A possible causative role for the recently discovered hepatitis C virus (HCV) in the development of hepatocellular carcinoma (HCC) was investigated by assay of sera from HCC patients in Japan for antibodies to a recombinant HCV antigen and to hepatitis B virus (HBV) antigens. Among the 253 HCC patients examined, 156 (61.7%) had no serum markers of either a previous or a current HBV infection (group I), 46 (18.2%) were negative for HBV surface antigen but positive for anti-HBV surface and/or anti-HBV core antibody, indicating the occurrence of a previous, transient HBV infection (group II), and 51 (20.2%) were chronically infected HBV carriers as evidenced by positivity for HBV surface antigen (group III). The prevalence of HCV antibody in group I (68.6%) and II (58.7%) patients was significantly higher than for group III (3.9%) or in 148 additional patients with other (non-HCC) cancers (10.1%) (P less than 0.01). Thus, there appears to be a strong association between HCV infection and the development of HCC, particularly in patients for which HBV infection cannot be implicated as a causative factor. The data also suggest an additional mode of transmission for HCV other than blood transfusion, since a history of blood transfusion was shown in only about 30% of the HCV antibody-positive HCC patients in groups I and II. A high prevalence of HCV antibody was also shown among patients with HCC whose disease was originally thought to be due to very high ethanol consumption.

Oxidative stress is associated with the degeneration of both motor neurons and skeletal muscles in amyotrophic lateral sclerosis (ALS). A free radical scavenger edaravone has been proven as a therapeutic drug for ALS patients, but the neuroprotective mechanism for the oxidative stress of ALS has not been fully investigated. In this study, we investigated oxidative stress in ALS model mice bearing both oxidative stress sensor nuclear erythroid 2‐related factor 2 (Nrf2) and G93A‐human Cu/Zn superoxide dismutase (Nrf2/G93A) treated by edaravone. In vivo Nrf2 imaging analysis showed the accelerated oxidative stress both in spinal motor neurons and lower limb muscles of Nrf2/G93A mice according to disease progression in addition to the enhancement of serum oxidative stress marker dROMS. These were significantly alleviated by edaravone treatment accompanied by clinical improvements (rotarod test). The present study suggests that in vivo optical imaging of Nrf2 is useful for detecting oxidative stress in ALS, and edaravone alleviates the degeneration of both motor neurons and muscles related to oxidative stress in ALS patients.

To quantitatively assess pathological gait, we developed a novel smartphone application for full-body human motion tracking in real time from markerless video-based images using a smartphone monocular camera and deep learning. As training data for deep learning, the original three-dimensional (3D) dataset comprising more than 1 million captured images from the 3D motion of 90 humanoid characters and the two-dimensional dataset of COCO 2017 were prepared. The 3D heatmap offset data consisting of 28 × 28 × 28 blocks with three red–green–blue colors at the 24 key points of the entire body motion were learned using the convolutional neural network, modified ResNet34. At each key point, the hottest spot deviating from the center of the cell was learned using the tanh function. Our new iOS application could detect the relative tri-axial coordinates of the 24 whole-body key points centered on the navel in real time without any markers for motion capture. By using the relative coordinates, the 3D angles of the neck, lumbar, bilateral hip, knee, and ankle joints were estimated. Any human motion could be quantitatively and easily assessed using a new smartphone application named Three-Dimensional Pose Tracker for Gait Test (TDPT-GT) without any body markers or multipoint cameras.