Peripheral inflammation is associated with impaired sadness recognition in euthymic bipolar patients.

BACKGROUND: Inflammation impairs cognitive function in healthy individuals and people with psychiatric disorders, such as bipolar disorder (BD). This effect may also impact emotion recognition, a fundamental element of social cognition. Our study aimed to investigate the relationships between pro-inflammatory cytokines and emotion recognition in euthymic BD patients and healthy controls (HCs). METHODS: We recruited forty-four euthymic BD patients and forty healthy controls (HCs) and measured their inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and TNF-α. We applied validated cognitive tasks, the Wisconsin Card-Sorting Test (WCST) and Continuous Performance Test (CPT), and a social cognitive task for emotion recognition, Diagnostic Analyses of Nonverbal Accuracy, Taiwanese Version (DANVA-2-TW). We analyzed the relationships between cytokines and cognition and then explored possible predictive factors of sadness recognition accuracy. RESULTS: Regarding pro-inflammatory cytokines, TNF-α was elevated in euthymic BD patients relative to HCs. In euthymic BD patients only, higher TNF-α levels were associated with lower accuracy of sadness recognition. Regression analysis revealed that TNF-α was an independent predictive factor of sadness recognition in patients with euthymic BD when neurocognition was controlled for. CONCLUSIONS: We demonstrated that enhanced inflammation, indicated by increased TNF-α, was an independent predictive factor of impaired sadness recognition in BD patients but not in HCs. Our findings suggested a direct influence of TNF-α on sadness recognition and indicated vulnerability to depression in euthymic BD patients with chronic inflammation.

Social cognitive deficit is associated with visuomotor coordination impairment and dopamine transporter availability in euthymic bipolar disorder.

BACKGROUND: Extensive evidence has suggested functional connections between co-occurring visuomotor and social cognitive deficits in neuropsychiatric disorders; however, such association has not been studied in bipolar disorder (BD). We aimed to investigate the relationship between visuomotor coordination and social cognition in the euthymic stage of BD (euBD). Given the shared neurobiological underpinnings involving the dopaminergic system and corticostriatal circuitry, we hypothesized a positive correlation between social cognition and visuomotor coordination in euBD patients. METHODS: 40 euBD patients and 59 healthy control (HC) participants underwent evaluation of social (Diagnostic Analysis of Nonverbal Accuracy 2-Taiwan version (DANVA-2-TW)), non-social cognitive function and visuomotor coordination. A subgroup of participants completed single-photon emission computed tomography for striatal dopamine transporter (DAT) availability assessment. RESULTS: EuBD patients showed impaired nonverbal emotion recognition (ps ≤ 0.033) and poorer visuomotor coordination (ps < 0.003) compared to HC, with a positive correlation between these two abilities (r = 0.55, p < 0.01). However, after considering potential confounding factors, instead of visuomotor coordination, striatal DAT availability was a unique predictor of emotion recognition accuracy in euBD (beta = 0.33, p = 0.001). CONCLUSION: Our study result supported a functional association between social cognition and visuomotor coordination in euBD, with striatal dopaminergic dysfunction emerged as a crucial contributing factor in their interrelation.

Increase of pullout strength of spinal pedicle screws with conical core: biomechanical tests and finite element analyses.

Screw loosening can threaten pedicle screw fixation of the spine. Conical screws can improve the bending strength, but studies of their pullout strength as compared with that of cylindrical screws have shown wide variation. In the present study, polyurethane foam with two different densities (0.32 and 0.16 gm/cm3) was used to compare the pullout strength and stripping torque among three kinds of pedicle screws with different degrees of core tapering. Three-dimensional finite element models were also developed to compare the structural performance of these screws and to predict their pullout strength. In the mechanical tests, pullout strength was consistently higher in the higher density foam and was closely related to screw insertion torque (r=0.87 and 0.81 for the high and low density foam, respectively) and stripping torque (r=0.92 and 0.78, respectively). Conical core screws with effective foam compaction had significantly higher pullout strength and insertion torque than cylindrical core screws (p<0.05). The results of finite element analyses were closely related to those of the mechanical tests in both situations with or without foam compaction. This study led to three conclusions: polyurethane foam bone yielded consistent experimental results; screws with a conical core could significantly increase pullout strength and insertion torque over cylindrical; and finite element models could reliably reflect the results of mechanical tests.