OBJECTIVE: To investigate the prevalence and influencing factors of low back pain in workers in automobile manufacturing plants. METHODS: A judgment sampling method was used to select 394 workers with working length ≥1 year in an automobile manufacturing plant as study subjects. A questionnaire survey was conducted to investigate the prevalence of low back pain in these workers using the Nordic Musculoskeletal Disorders Questionnaire. RESULTS: The prevalence of low back pain in these study subjects was 28. 9%( 114/394). The multivariate logistic regression analysis results showed that the relative risk ranked from high to low is as follow: uncomfortable working posture [Odds ratio( OR) =7. 31,95% confidence interval( 95% CI) = 2. 92-18. 28],feeling tired after work( OR = 5. 34,95% CI = 1. 22-23. 32],the commu time more than 30 minutes( OR = 2. 76,95% CI = 1. 38-5. 52),insufficient operating space( OR = 2. 22,95% CI = 1. 28-3. 83),hand or arm frequently used at work( OR = 2. 08,95% CI = 1. 14-3. 78) and age( OR = 2. 00,95% CI = 1. 19-3. 35),that were all risk factors of low back pain( P < 0. 05). CONCLUSION: The frequent use of hand or arm at work,insufficient operating space,uncomfortable working posture,feeling tired after work,and long commute time are the main influencing factors affecting the low back pain of automobile manufacturing workers.

OBJECTIVETo investigate the effect of baicalein and quercetin on the enzymatic resistance of dentin matrix collagen.

METHODSBaicalein, quercetin and proanthocyanidin were dissolved in 20% dimethyl sulfoxide (DMSO) ethanol and prepared into pretreatment agents with a concentration of 50 g/L. Demineralized dentin specimens were prepared and immersed in pretreatment agents at 37 °C for 24 h, then they were digested in solution containing type?collagenase. The pretreatment agents of blank control group and negative control group were 20% DMSO ethanol, blank control group were digested in solution without collagenase. The ultimate tensile strength (UTS) and the hydroxyproline content of enzymolysis liquid in each group were measured respectively after collagenase digestion for 24 h, the dentin collagen morphology were observed under a field emission scanning electron microscopic (FE-SEM) after collagenase digestion for 12 h.

RESULTSAfter collagenase digestion for 24 h, the baicalein group had the highest UTS [(16.00±1.31) MPa], followed by proanthocyanidin group [(12.64±0.91) MPa], blank control group [(7.84±1.18) MPa], quercetin group [(3.20±1.07) MPa], and negative control group (0 MPa). Significant differences were detected among the UTS in each two group (P < 0.01). The hydroxyproline content in blank control group was the lowest [(0.40 ± 0.16) mg/L], followed by baicalein group[(2.95 ± 0.18) mg/L], proanthocyanidin group [(4.78±0.38) mg/L], quercetin group[(28.22±1.53) mg/L], and negative control group [(34.39±0.39) mg/L]. There were significant differences among the hydroxyproline contents in each group (P < 0.01). After collagenase digestion for 12 h, intact collagen network could be seen in blank control group under a FE-SEM. Collagen network in negative control group suffered nearly complete destruction and collapsed. In quercetin group, most of collagen collapsed. In proanthocyanidin group, a small portion of collagen destruction and collapse could be seen. In baicalein group, collagen network remained intact.

CONCLUSIONSThe use of baicalein and quercetin could improve enzymatic resistance of dentin matrix collagen at a concentration of 50 g/L. The effect of baicalein was better than that of proanthocyanidin while the effect of quercetin was weaker than that of proanthocyanidin.

Antioxidants ; pharmacology ; Collagen ; metabolism ; Collagenases ; metabolism ; Dental Bonding ; Dentin ; drug effects ; metabolism ; Dentin-Bonding Agents ; Flavanones ; pharmacology ; Proanthocyanidins ; Quercetin ; pharmacology ; Tensile Strength

Arnebiae Radix is used widely in TCM external treatment. It has obvious curative effect on skin diseases， wound infection and local inflammation， and is used to treat water and fire burns， skin ulcers， eczema， psoriasis， vitiligo and atopic dermatitis， etc. The clinical and commercial preparations mainly include ointment， liniment and suppository. Modern research has proved that microcapsules， nano-micelles， nanofiber membranes， nanogels and other novel nanoformulations can significantly improve the stability of drug-effective substances， improve local drug concentration and targeting， and perform sound drug release properties in vitro. This paper reviews the variety and application of Arnebiae Radix traditional preparations for external use and the research progress of novel nanoformulations of Arnebiae Radix， from which we prospect to provide some valuable references for the future application and development of Arnebiae Radix external preparations.