Response of face-selective brain regions to trustworthiness and gender of faces

Neuropsychological and neuroimaging studies have demonstrated a role for the amygdala in processing the perceived trustworthiness of faces, but it remains uncertain whether its responses are linear (with the greatest response to the least trustworthy-looking faces), or quadratic (with increased fMRI signal for the dimension extremes). It is also unclear whether the trustworthiness of the stimuli is crucial or if the same response pattern can be found for faces varying along other dimensions. In addition, the responses to perceived trustworthiness of face-selective regions other than the amygdala are seldom reported. The present study addressed these issues using a novel set of stimuli created through computer image-manipulation both to maximise the presence of naturally occurring cues that underpin trustworthiness judgments and to allow systematic manipulation of these cues. With a block-design fMRI paradigm, we investigated neural responses to computer-manipulated trustworthiness in the amygdala and core face-selective regions in the occipital and temporal lobes. We asked whether the activation pattern is specific for differences in trustworthiness or whether it would also track variation along an orthogonal male-female gender dimension. The main findings were quadratic responses to changes in both trustworthiness and gender in all regions. These results are consistent with the idea that face-responsive brain regions are sensitive to face distinctiveness as well as the social meaning of the face features.     

Comparison of pulmonary diseases in common variable immunodeficiency and X‐linked agammaglobulinaemia

Background and objective: Pulmonary disease is the most common complication in patients with common variable immunodeficiency (CVID) or X‐linked agammaglobulinaemia (XLA). Pulmonary disease may progress despite immunoglobulin replacement therapy. In this study pulmonary complications were compared in patients with CVID or XLA. Methods: Pulmonary complications were evaluated in 115 patients (76 with CVID and 39 with XLA) by reviewing hospital records of chest infections, pulmonary function tests and high‐resolution CT scans. Results: Thirty‐two patients with XLA (82%) presented with 59 episodes of pneumonia before diagnosis, whereas 15 patients (38.4%) experienced pneumonia after immunoglobulin replacement therapy (1.67 vs 0.45 episodes per patient per year). Among the CVID patients, 196 episodes of pneumonia were documented in 59 patients (77.6%) before diagnosis, while 36 patients (47.3%) experienced pneumonia after therapy (1.11 vs 0.58 episodes of pneumonia per patient per year). Forty‐seven (41%) patients (38 with CVID and 9 with XLA) developed chronic lung disease. The CVID patients developed more complications, including bronchiectasis and lymphoid interstitial pneumonitis, than the XLA patients. Conclusions: Patients with CVID had a greater likelihood of developing lung disease, possibly due to delayed diagnosis and immune dysregulation, as compared with XLA patients. Early diagnosis of patients with primary antibody deficiencies and adequate i.v. immunoglobulin replacement therapy substantially reduces the number of pulmonary infections. However, CVID patients are prone to progression of lung disease despite optimal immunoglobulin therapy because of the nature of the disease. This important issue should be addressed in further studies.     

Comparing performance among male and female candidates in sex-specific clinical knowledge in the MRCGP

Background

Patients often seek doctors of the same sex, particularly for sex-specific complaints and also because of a perception that doctors have greater knowledge of complaints relating to their own sex. Few studies have investigated differences in knowledge by sex of candidate on sex-specific questions in medical examinations.

Aim

The aim was to compare the performance of males and females in sex-specific questions in a 200-item computer-based applied knowledge test for licensing UK GPs.

Design and setting

A cross-sectional design using routinely collected performance and demographic data from the first three versions of the Applied Knowledge Test, MRCGP, UK.

Method

Questions were classified as female specific, male specific, or sex neutral. The performance of males and females was analysed using multiple analysis of covariance after adjusting for sex-neutral score and demographic confounders.

Results

Data were included from 3627 candidates. After adjusting for sex-neutral score, age, time since qualification, year of speciality training, ethnicity, and country of primary medical qualification, there were differences in performance in sex-specific questions. Males performed worse than females on female-specific questions (–4.2%, 95% confidence interval [CI] = –5.7 to –2.6) but did not perform significantly better than females on male-specific questions (0.3%, 95% CI = –2.6 to 3.2%.

Conclusion

There was evidence of better performance by females in female-specific questions but this was small relative to the size of the test. Differential performance of males and females in sex-specific questions in a licensing examination may have implications for vocational and post-qualification general practice training.     

Enhancing the [13C]bicarbonate signal in cardiac hyperpolarized [1‐13C]pyruvate MRS studies by infusion of glucose,insulin and potassium

A change in myocardial metabolism is a known effect of several diseases. MRS with hyperpolarized ¹³C‐labelled pyruvate is a technique capable of detecting changes in myocardial pyruvate metabolism, and has proven to be useful for the evaluation of myocardial ischaemia in vivo. However, during fasting, the myocardial glucose oxidation is low and the fatty acid oxidation (β‐oxidation) is high, which complicates the interpretation of pyruvate metabolism with the technique. The aim of this study was to investigate whether the infusion of glucose, insulin and potassium (GIK) could increase the myocardial glucose oxidation in the citric acid cycle, reflected as an increase in the [¹³C]bicarbonate signal in cardiac hyperpolarized [1‐¹³C]pyruvate MRS measurements in fasted rats. Two groups of rats were infused with two different doses of GIK and investigated by MRS after injection of hyperpolarized [1‐¹³C]pyruvate. No [¹³C]bicarbonate signal could be detected in the fasted state. However, a significant increase in the [¹³C]bicarbonate signal was observed by the infusion of a high dose of GIK. This study demonstrates that a high [¹³C]bicarbonate signal can be achieved by GIK infusion in fasted rats. The increased [¹³C]bicarbonate signal indicates an increased flux of pyruvate through the pyruvate dehydrogenase enzyme complex and an increase in myocardial glucose oxidation through the citric acid cycle. Copyright © 2013 John Wiley & Sons, Ltd.