Objective To study the effect of maca extract on sport fatigue and its antioxidant effect.Methods 50 healthy male Wistar rats were randomly divided into control group (normal breeding,without swimming,equal amount of distilled water for gavage),simple swimming group (swimming,equal amount of distilled water for gavage),swimming and medicine group (divided into maca extract 4.0,8.0 and 16.0 g/(kg· bw) groups,respectively),10 rats in each group.All rats were freely swimming in the circulating water flow daily for 15 days.On the 16th day of experiment,liver tissue samples were collected.The liver lipid peroxide (LPO),superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) and liver glycogen level were determined.Results When rats were administered with maca extract at the doses of 4.0,8.0,16.0 g/(kg· bw),respectively,the swimming time before sinking and the total swimming time were increased by 18.99%,64.46% and 90.69%,and 18.99%,56.23% and 94.72%,respectively,while the numbers of times of sinking were decreased by 27.44%,42.86%,64.11% (P<0.01),respectively,compared with the swimming rats without maca extract treatment.The LPO content in the liver of rats treated with maca extract 4.0,8.0,16.0 g/(kg· bw) were reduced by 31.31%,42.00% and 31.31%,respectively,while the levels of SOD,GSH-Px and liver glycogen were enhanced by 25.92%,31.82%,62.09%,12.33%,23.01%,46.36% and 17.83%,44.69%,62.99%,respectively,over those of rats without maca extract treatment.Conclusions Maca extract reduces the liver LPO level,increases liver glycogen level,improves the SOD and GSH-Px activity,therefore,plays a protective role in sport fatigue.

Objective To explore the relationship of time and analgesic effect of buccal acupuncture on rabbits with rheumatoid arthritis (RA),so as to provide the experimental basis for the clinical practice of buccal acupuncture.Methods Altogether 40 rabbits were randomly divided into normal group,model group,body acupuncture group and buccal acupuncture group (each n =10).RA model was induced by subcutaneous injection of ovalbumin.After modeling,rabbits of body acupuncture group were needled at the acupoint of bilateral “Xiyan”and “Tsusanli”and those of buccal acupuncture group were needled at the buccal acupoint of “knee”once daily for ten times.Heat pain threshold at the time point of 0,5, 15,30,60,120,and 240 minutes were recorded at the 1 st ,4th ,7 th ,and 10th treatment.Results The buccal acupuncture and body acupuncture both showed definite analgesia effect.The heat pain threshold of buccal acupuncture group began to increase after five-minute treatment,reached the peak value at the 30th minute,then declined at the 60th minute to the same as that before treatment at the 240th minute.The variation trend of heat pain threshold of body acupuncture group was in common with that of buccal acu-puncture group,but the pain threshold at the 240th minute was higher than that before treatment.Con-clusion Buccal acupuncture against pain showed obvious effect-time relationship which was as similar as that of body acupuncture,but the onset time of buccal acupuncture was shorter than that of body acu-puncture,and the duration was shorter.Furthermore,the analgesic effect of buccal acupuncture showed no relationship with times.

Objective To study the effect of noise pollution on serum hormone and heat shock protein-70(Hsp-70)levels in rats. Methods Forty male Wistar rats were randomly divided into control group(normal), experimental group(further divided into 35,65 and 85 dB three groups), each group 10 animals, stimulated for 30 min once a day, continually stimulated for consecutive 20 days. On the 21st day of experiment,the serum noradrenaline(NA),testosterone (T),dopamine(DA)and Hsp-70 levels were determined by enzyme-linked immunosorbent assay(ELISA). Results Compared with the control group, the body weight of experimental group(35, 65 and 85 dB groups)was reduced by 23.45%,30.13%, and 35.64%, respectively The serum T and DA levels were decreased by 9.12%, 20.06%, 37.99% and 15.49%, 8.31%, 24.88%, respectively; while the serum NA and Hsp-70 levels were increased by 35.08%, 171.52%,197.86%, and 39.34%, 195.09%, and 285.25%, respectively. All the result showed a significant difference(P<0.01). Conclusions Noise pollution can significantly affect the serum levels of hormone and heat shock protein-70 expression in rats.

New threats posed by the emerging circulating variants of SARS-CoV-2 highlight the need to find conserved neutralizing epitopes for therapeutic antibodies and efficient vaccine design. Here, we identified a receptor-binding domain (RBD)-binding antibody, XG014, which potently neutralizes β-coronavirus lineage B (β-CoV-B), including SARS-CoV-2, its circulating variants, SARS-CoV and bat SARSr-CoV WIV1. Interestingly, antibody family members competing with XG014 binding show reduced levels of cross-reactivity and induce antibody-dependent SARS-CoV-2 spike (S) protein-mediated cell-cell fusion, suggesting a unique mode of recognition by XG014. Structural analyses reveal that XG014 recognizes a conserved epitope outside the ACE2 binding site and completely locks RBD in the non-functional "down" conformation, while its family member XG005 directly competes with ACE2 binding and position the RBD "up". Single administration of XG014 is effective in protection against and therapy of SARS-CoV-2 infection in vivo. Our findings suggest the potential to develop XG014 as pan-β-CoV-B therapeutics and the importance of the XG014 conserved antigenic epitope for designing broadly protective vaccines against β-CoV-B and newly emerging SARS-CoV-2 variants of concern.
Angiotensin-Converting Enzyme 2 ; Antibodies, Neutralizing ; Antibodies, Viral ; COVID-19 ; Epitopes ; Humans ; SARS-CoV-2/genetics* ; Spike Glycoprotein, Coronavirus/genetics*