ABSTRACT
This study proposed a pupillary light reflex (PLR) inherent model based on the system identification method to demonstrate the dynamic physiological mechanism of the PLR, in which pupillary constriction and dilation are controlled by the sympathetic and parasympathetic nervous system. This model was constructed and verified by comparing the simulated and predicted PLR response with that of healthy participants. The least root-mean-square error (RMSE) of simulated PLR response was less than 0.7% when stimulus duration was under 3 ms. The RMSE of predicted PLR response increased by approximately 6.76%/s from the stimulus duration of 1 ms to 3 s, when the model directly used the parameters extracted from the PLR at the stimulus duration of 10 ms. When model parameters were derived from the regression by the measured PLR response, the RMSE kept under 8.5%. The model was applied to explore the PLR abnormalities of the people with Diabetic Mellitus (DM) by extracting the model parameters from 42 people with DM and comparing these parameters with those of 42 healthy participants. The parameter in the first-order term of the elastic force of the participants with DM was significantly lower than that of the healthy participants (p < 0.05). The sympathetic force and sympathetic action delay of the participants with DM were significantly larger (p < 0.05) and longer (p < 0.0001) than that of the healthy ones, respectively. The reason might be that the sympathetic nervous system, which controls the dilator muscle, degenerated in diabetic patients.
ABSTRACT
Xanthohumol is one of the main flavonoids in hop extracts and in beer. Very few investigations of xanthohumol have studied hepatocellular carcinoma. In this study, the inhibitory effects of xanthohumol on human hepatocellular carcinoma cell lines were investigated. The IC(50) values of xanthohumol for two hepatocellular carcinoma cell lines and one normal hepatocyte cell line were 108, 166 and 211 microm, respectively. Normal murine hepatocyte cell line had more resistance to xanthohumol than hepatocellular carcinoma cell lines. Besides, the inhibitory effects of xanthohumol on human hepatocellular carcinoma cell lines were attributed to apoptosis as indicated in the results of flow cytometry, fluorescent nuclear staining and electrophoresis of oligonucleosomal DNA fragments. Hop xanthohumol was more efficient in the growth inhibition of hepatocellular carcinoma cell lines than the flavonoids silibinin and naringin from thistle and citrus. It was shown for the first time that xanthohumol from hops effectively inhibits proliferation of human hepatocellular carcinoma cells in vitro.
