Involvement of cannabinoid type 1 receptor in fasting-induced analgesia.

The endocannabinoid system (ECS) is known to modulate not only food intake but also pain, especially via the cannabinoid type 1 receptor (CB1R) expressed throughout the central nervous system and the peripheral tissues. Our previous study demonstrated that fasting produces an analgesic effect in adult male mice, which is reversed by intraperitoneal (i.p.) administration of CB1R antagonist (SR 141716). In the present study, we further examined the effect of CB1R expressed in the peripheral tissues. In the formalin-induced inflammatory pain model, i.p. administration of peripherally restricted CB1R antagonist (AM 6545) reversed fasting-induced analgesia. However, intraplantar administration of SR 141716 did not affect fasting-induced analgesia. Furthermore, mRNA expression of CB1R did not change in the formalin model by fasting in the dorsal root ganglia. The formalin-induced c-Fos expression at the spinal cord level was not affected by fasting, and in vivo recording from the superficial dorsal horn of the lumbar spinal cord revealed that fasting did not affect formalin-induced neural activity, which indicates minimal involvement of the spinal cord in fasting-induced analgesia. Finally, when we performed subdiaphragmatic vagotomy to block the hunger signal from the gastrointestinal (GI) system, AM 6545 did not affect fasting-induced analgesia, but SR 141716 still reversed fasting-induced analgesia. Taken together, our results suggest that both peripheral and central CB1Rs contribute to fasting-induced analgesic effects and the CB1Rs in the GI system which transmit fasting signals to the brain, rather than those in the peripheral sensory neurons, may contribute to fasting-induced analgesic effects.

Effect of Applied Current Density on Anodic Oxidation Behavior of AZ31 Mg Alloy in NaOH Solution.

This paper reports three different anodic oxidation behaviors of AZ31 Mg alloy in NaOH solutions, depending on the applied current density and concentration of NaOH between 0.1 M and 0.6 M. When applied current density is lower than about 30 mA/cm², dark anodic film was formed with a very low film formation voltage of less than 6 V and it was found to grow with anodizing time. If applied current density is higher than a critical value about 30 mA/cm², bright metallic surface appearance with small number of pits and/or trenches was obtained. The formation of the pits or trenches was attributed to the result of repeated formation and detachment of plasma electrolytic oxidation (PEO) films at the same site or neighboring places, as strongly supported by repeated micro-arc generations at the same surface site of the specimen during the anodic oxidation process. When applied current density exceeds about 80 mA/cm² in 0.6 M NaOH solution, micro-arcs were generated uniformly over the entire surface, resulting in grey surface appearance and the formation of PEO films with cracks and pores. Based on the experimental results obtained in this work, it is concluded that dark anodic films and grey colored PEO films can be formed on the AZ31 Mg alloy surface in NaOH solution if the applied current density is controlled to be lower than a critical value and if the applied current density and NaOH concentration are controlled to exceed critical values of about 80 mA/cm² and 0.6 M, respectively.

A New Dynamic Complex Baseband Pulse Compression Method for Chirp-Coded Excitation in Medical Ultrasound Imaging.

Chirp-coded excitation can increase the signal-to-noise ratio (SNR) without degrading the axial resolution. Effective pulse compression (PC) is important to maintain the axial resolution and can be achieved with radio frequency (RF) and complex baseband (CBB) data (i.e., and , respectively). can further reduce the computational complexity compared to ; however, suffers from a degraded SNR due to tissue attenuation. In this paper, we propose a new dynamic CBB PC method ( that can improve the SNR while compensating for tissue attenuation. The compression filter coefficients in the method are generated by dynamically changing the demodulation frequencies along with the depth. For PC, the obtained coefficients are independently applied to the in-phase and quadrature components of the CBB data. To evaluate the performance of the proposed method, simulation, phantom, and in vivo studies were conducted, and all three studies showed improved SNR, i.e., maximally 3.87, 7.41, and 5.75 dB, respectively. In addition, the measured peak range sidelobe level of the proposed method yielded lower values than the and , and it also derived a suitable target location, i.e., a <0.07-mm target location error, while maintaining the axial resolution. In an in vivo abdominal experiment, the method depicted brighter and clearer features in the hyperechoic region because highly correlated signals were produced by compensating for tissue attenuation. These results demonstrated that the proposed method can improve the SNR of chirp-coded excitation while preserving the axial resolution and the target location and reducing the computational complexity.

Impairment of driving ability and neuropsychological function in patients with MHE disease.

Minimal hepatitis encephalopathy (MHE) is a liver cirrhosis complication that does not show symptoms of overt hepatitis encephalopathy (OHE) but can be detected using specific complementary neuropsychological and neurophysiological evaluations. Patients with MHE show abnormalities in cognitive functions, which can increase the risk of automobile accidents. The aim of this study was to compare the cognitive functioning of patients with MHE to patients with other liver disease and to compare their driving abilities, using a driving simulator and the Stim(2) software. Thirty-eight participants, who were not diagnosed with OHE but were diagnosed with chronic hepatitis and liver cirrhosis, took part in the study. The results indicate that patients with MHE show reduced level of cognitive functioning, which may affect their ability to drive safely. We cautiously predict that any future guidelines based on this knowledge may help reduce the incidence of traffic accidents caused by drivers with decreased with driving abilities.