The normal range of maximum mouth opening and its correlation with height or weight in the young adult Chinese population.

BACKGROUND/PURPOSE: Maximum mouth opening (MMO) is an important diagnostic reference for dental clinicians. However, the relationship between either body height or weight of the individual and their subsequent MMO has, up to now, been unclear. The purpose of this study was to measure the MMO of healthy young Chinese adults and to analyze the possible correlation of MMO with either height or weight. MATERIALS AND METHODS: A total of 452 young Chinese adults, aged 20-35 years (238 males, 214 females) were selected for this cross-sectional study. We recorded the MMO, age, sex, height, and weight of the participants. Two standardized examiners performed the clinical oral assessments. Independent sample t tests were used to examine the difference in MMO relative to sex. Pearson's correlation and simple linear regression were used to estimate the correlation between MMO and either height or weight. RESULTS: The average MMO across the 452 participants was 52.02 ± 5.09 mm, and the average MMO of males (54.18 ± 5.21 mm) was significantly larger than that of females (49.62 ± 3.69 mm; P < 0.001). The mean MMO was moderately positively correlated with height (r = 0.54; P < 0.001) and weight (r = 0.50; P < 0.001). In the regression model, it was estimated that, for every 10 cm or 10 kg, MMO increased by about 3.6 mm or 1.8 mm, respectively. CONCLUSION: With the limits of the present study, both height and weight were found to be significantly correlated with the MMO of Chinese young adults and may be significant predictors of MMO measurement.

Assessment of serum malondialdehyde, uric acid, and vitamins C and E levels in patients with recurrent aphthous stomatitis.

BACKGROUND/PURPOSE: Recurrent aphthous stomatitis (RAS) is a common oral mucosal disease. Recently, oxidative stress has been thought to play a major role in the etiopathogenesis of RAS. The aim of this investigation was to compare the serum levels of an important oxidant agent [malondialdehyde (MDA)] and nonenzymatic antioxidants [uric acid (UA) and vitamins C and E] in patients with RAS versus healthy individuals. MATERIALS AND METHODS: Ninety-seven patients with idiopathic minor RAS and 97 race-, age-, and sex-matched healthy individuals were included in this study. All these individuals were allocated to three groups: RAS patients in the active stage (Group A); the same RAS patients in Group A in the remission stage (Group B); and healthy individuals without RAS (Group C). The serum levels of MDA, UA, and vitamins C and E were measured by the spectrophotometric method. Independent sample t test and paired t test were performed for statistical evaluation. RESULTS: Serum MDA level of Group A was significantly higher than that of Group B (P = 0.040) or Group C (P = 0.011), whereas the serum level of vitamin E was significantly decreased in Group A as compared with Group B (P = 0.012) or Group C (P = 0.001). No statistically significant differences were found between Group B and Group C in terms of MDA, UA, and vitamins C and E serum levels (P > 0.05). CONCLUSION: With the double-faced character of oxidant/antioxidant, UA and vitamin C may not play a crucial role in the pathogenesis of RAS. However, MDA and vitamin E can be used as indicators for RAS.

[Porewater Dissolved Methane in Cyperus malaccensis Marshes Along Salinity Gradient in the Minjiang River Estuary].

Physicochemical properties of soil and dissolved methane concentrations of porewater in the sediments of the Cyperus malaccensis marshes along a salinity gradient in the Minjiang River estuary were evaluated, and the spatial-temporal characteristics and main impact factors were discussed. The average concentrations of dissolved methane in porewater were 331.18, 299.94 and 638.58 µmol x L(-1), respectively in the Shanyutan, Bianfuzhou and Xiayangzhou wetlands in summer. In the winter, they were 9.04, 266.67 and 322.68 µmol x L(-1), respectively. The dissolved methane concentration in porewater was higher in summer than those in winter (P < 0.05). Overall, the concentrations of dissolved methane in porewatdr showed an increasing trend from brackish to freshwater marshes. Multivariate statistics analysis showed that the concentrations of dissolved methane in porewater was positively correlated with soils temperature and DOC (P < 0.05), but negatively correlated with soils pH, salinity, and the concentrations of porewater SO4(2-) and Cl-. Spatial-temporal distribution of porewater dissolved methane in estuarine marshes represents a final result of multiple factors, including soil physicochemical properties and hydrodynamic condition.

Metabolic profiling of GuanXin II prescription based on metabolic fingerprinting and chemical analysis.

A sensitive LC/MS method was established to investigate the in vivo metabolism of GuanXin II prescription, a five-component Chinese herbal medicine formulation. Rat plasma, bile, urine, and feces were collected and analyzed following oral administration of the water decoction. A total of 50 compounds were identified, including 17 prototypes and 33 metabolites underwent methylation, oxidation, hydrolysis, sulfate conjugation, glucuronide conjugation, and glutathion conjugation. In addition, the component herb of the formulation from which the metabolites were derived was also identified. Among the five component herbs, Rhizoma Chuanxiong, Flos Carthami, and Lignum Dalbergiae Odoriferae were actively metabolized, contributing 26 metabolites and 2 prototypes, while Radix Salviae Miltiorrhizae and Radix Paeoniae Rubra underwent less biotransformation, yielding 7 metabolites and 15 prototypes. This is the first study on the metabolic profile of GuanXin II prescription. The results could be valuable to elucidate the material basis of this formulated Chinese medicine.

Characterization of chemical constituents in Guan Xin II decoction by liquid chromatography coupled with electrospray ionization-mass spectrometry.

Guan Xin II decoction (GX II) is a widely used traditional Chinese medicine (TCM) formula for the treatment of coronary heart diseases. However, the comprehensive chemical analysis of the formulated GX II is not clarified yet. An HPLC-DAD-ESI-MSn method was established to analyze GX II and its five component herbs, respectively. A total of 57 compounds, including phenolic acids, glycosides, flavonoids, and alkaloids were identified or tentatively characterized on the basis of their mass spectra or by comparison with reference standards. This is the first time that the chemical composition of GX II was elucidated by LC/MS. The established method will be used for quality control and pharmacokinetic studies of GX II.

Metabolic analysis of four phenolic acids in rat by liquid chromatography-tandem mass spectrometry.

A liquid chromatography-diode array detection-electrospray ionization ion trap mass spectrometry (LC-DAD-ESI-MS(n)) method was established for the analysis of danshensu, caffeic acid, ferulic acid and isoferulic acid in rat plasma, bile, urine and feces after oral administration or intravenous injection. Liquid-liquid extraction was employed for the preparation of biosamples, and the chromatographic separation was carried out using an Agilent Zorbax Extend C(18) reversed phase column and acetonitrile-0.1% formic acid as the mobile phase. Totally nineteen metabolites were detected and identified as prototype, methylated, hydroxylated, sulfated and glucuronized conjugates. The metabolism of the individual phenolic acids in biosamples was investigated, and the metabolic pathway was proposed. By comparing the metabolism of different compounds which shared similar structures, we were able to find that methylation was the main pathway of danshensu metabolism, and the double bond on the side chain was critical for the drug excretion via bile and the formation of glucuronized conjugates. The results proved that the established method was simple, sensitive and reliable, which could be used to detect and identify the structures of metabolites and to better understand their in vivo metabolism.

Determination of danshensu in rat plasma and tissues by high-performance liquid chromatography.

A systematic study on pharmacokinetics and tissue distribution of danshensu (one of the major active components from Salvia miltiorrhizae) is conducted using a rapid and sensitive high-performance liquid chromatographic (HPLC) method. Before HPLC analysis, biological samples are pretreated with a liquid-liquid extraction. Separation of danshensu and internal standard is achieved on an Agilent Zorbax C18 column with a mobile phase made up of acetonitrile and 0.05% trifluoracetic acid at a flow rate of 0.8 mL/min. The calibration curves in plasma and tissues are linear in the given concentration ranges, with r2 no less than 0.99. The intra-day and inter-day relative standard deviations in the measurement of quality control samples are less than 15%, and the accuracies are in the range of 86-115%. The recoveries of danshensu in plasma and tissues are among 80% to 118%. Meanwhile, the multi-peaks in pharmacokinetic profiles are observed. The method is successfully applied to the pharmacokinetics and tissue distribution study of danshensu after a single oral administration of 50.0 mg/kg sodium danshensu to rats.

Structural characterization of metabolites of salvianolic acid B from Salvia miltiorrhiza in normal and antibiotic-treated rats by liquid chromatography-mass spectrometry.

This study was conducted to compare the in vivo metabolites of salvianolic acid B (Sal B) between normal rats and antibiotic-treated rats and to clarify the role of intestinal bacteria on the absorption, metabolism and excretion of Sal B. A valid method using LC-MS(n) analysis was established for identification of rat biliary and fecal metabolites. And isolation of normal rat urinary metabolites by repeated column chromatography was applied in this study. Four biliary metabolites and five fecal metabolites in normal rats were identified on the basis of their MS(n) fragmentation patterns. Meanwhile, two normal rat urinary metabolites were firstly identified on the basis of their NMR and MS data. In contrast, no metabolites were detected in antibiotic-treated rat urine and bile, while the prototype of Sal B was found in antibiotic-treated rat feces. The differences of in vivo metabolites between normal rats and antibiotic-treated rats were proposed for the first time. Furthermore, it was indicated that the intestinal bacteria showed an important role on the absorption, metabolism and excretion of Sal B. This investigation provided scientific evidence to infer the active principles responsible for the pharmacological effects of Sal B.