[Protective effects of Polygonatum odoratum polysaccharides on alcohol-induced injury of HepG2 cells and its mechanisms].

Objective: To investigate the protective effects of Polygonatum odoratum polysaccharides (POP) on alcohol-induced injury of HepG2 cells and its potential molecular mechanisms. Methods: After screening the appropriate concentration of alcohol-treated HepG2 cells and the intervention concentration of POP by MTT method, HepG2 cells were divided into three groups according to different intervention concentrations (200 µg/L, 400 µg/L and 600 µg/L) of POP, and the blank group without POP. After pretreated for 1 h, HepG2 cells were treated with 4% alcohol for 24 h. The activities of intracellular alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and the levels of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNF- α) were measured. The protein expressions of Kelch-like epichlorohydrin-associated protein-1 (Keap1), phosphorylated nuclear factor E2-related factor 2 (p-Nrf2), phosphoamide adenine dinucleotide quinone oxidoreductase -1 (NQO1), B lymphocyte tumor-2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase 3 were detected. Results: Compared with the HepG2 cells treated with 4% alcohol, POP at the various concentrations could effectively down-regulate the activities of ALT and AST in HepG2 cells induced by alcohol (P＜0.05). The levels of IL-1ß and TNF-α in the 200 µg/L POP treated group were decreased significantly (P＜0.05), while the level of GSH was increased significantly (P＜0.01). The levels of ROS, MDA, IL-1ß and TNF-α in the 400 µg/L and 600 µg/L POP treated groups were decreased significantly (P＜0.05 or P＜0.01), while the GSH level was increased significantly (P＜0.01). POP effectively up-regulated the expressions of p-Nrf2 and NQO1 protein in HepG2 cells induced by alcohol, and also down-regulated the Bax/Bcl-2 index (P＜0.05), and inhibited the protein expressions of Keap1 and cleaved-caspase-3 (P＜0.05). Conclusion: POP can improve alcohol-induced oxidative stress injury in HepG2 cells by regulating the Nrf2/Keap1 pathway, thereby reducing the inflammatory index and apoptosis level of HepG2 cells. Among them, 400 µg/L and 600 µg/L POP have better intervention effects.

Pathogenic Hydrogel? A Novel-Entrapment Neuropathy Model Induced by Ultrasound-Guided Perineural Injections.

Entrapment neuropathy (EN) is a prevalent and debilitative condition caused by a complex pathogenesis that involves a chronic compression-edema-ischemia cascade and perineural adhesion that results in excessive shear stress during motion. Despite decades of research, an easily accessible and surgery-free animal model mimicking the mixed etiology is currently lacking, thus limiting our understanding of the disease and the development of effective therapies. In this proof-of-concept study, we used ultrasound-guided perineural injection of a methoxy poly(ethylene glycol)-b-Poly(lactide-co-glycoilide) carboxylic acid (mPEG-PLGA-BOX) hydrogel near the rat's sciatic nerve to induce EN, as confirmed sonographically, electrophysiologically, and histologically. The nerve that was injected with hydrogel appeared unevenly contoured and swollen proximally with slowed nerve conduction velocities across the injected segments, thus showing the compressive features of EN. Histology showed perineural cellular infiltration, deposition of irregular collagen fibers, and a possible early demyelination process, thus indicating the existence of adhesions. The novel method provides a surgery-free and cost-effective way to establish a small-animal model of EN that has mixed compression and adhesion features, thus facilitating the additional elucidation of the pathophysiology of EN and the search for promising treatments.

Feasibility of human T-lymphotropic virus type I screening using pooled sera.

BACKGROUND AND PURPOSE: The human T-cell lymphotropic virus type I (HTLV-I) seroprevalence rate among volunteer blood donors in Taiwan is low. To study the feasibility of HTLV-I enzyme immunoassay (EIA) screening using pooled sera, we prospectively compared its sensitivity to that of the routine test for each donor. METHODS: HTLV-I EIA tests for each serum sample and a pooled-sera test with 50 samples from voluntary donated blood samples were performed concurrently to assess the effectiveness and cost savings of this screening method. RESULTS: Of 135,606 blood samples from volunteer donors tested for HTLV-I infection, 60 samples (0.044%) were HTLV-I EIA-positive using the routine method. Among these, the positive results were confirmed by Western blot in 22 samples (36.7%). In the pooled-sera test, 17 of 2,713 pooled samples were EIA-positive and these results were all confirmed by Western blot. Five of the 22 (22.7%) EIA-positive samples had a false-negative result in the pooled-sera test. Serial dilution in these five cases revealed that the maximum dilution before loss of sensitivity was 8-fold for two specimens and 16-fold for three specimens. CONCLUSION: In this study, the 50-pooled sera test had higher specificity (100%), but lower sensitivity (77.3%), than the routine HTLV-I screening. Our results suggest that use of a pooling method with five samples would leave a reasonable safety margin and be feasible for HTLV-I mass screening in areas with low seroprevalence for HTLV-I infection.