Hormone replacement therapy and periodontitis progression in postmenopausal women: A prospective cohort study.

OBJECTIVE: This study aimed to investigate the responses of periodontal environment to hormone replacement therapy (HRT) in postmenopausal women with or without periodontitis. BACKGROUND: HRT is a common and effective strategy for controlling menopausal symptoms, while the changes of periodontal environment under it, particularly in postmenopausal women with periodontitis, remain unclear. METHODS: As a prospective cohort study, a total of 97 postmenopausal women receiving HRT were screened, including 47 with and 50 without periodontitis. Correspondingly, 97 women did not receiving HRT were screened as controls during the same period. The full-mouth sulcus bleeding index (SBI), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were measured using periodontal probes. The levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in the gingival crevicular fluid were measured using enzyme-linked immunosorbent assay. In addition, cone beam computed tomography was performed to measure the alveolar bone height (ABH) and bone mineral density (BMD). RESULTS: In postmenopausal women without periodontitis, no significantly changes on periodontal parameters were observed after HRT. In women with stage II periodontitis, SBI, BOP, IL-6, and TNF-α were significant decreased after one year and two years of HRT. Compared to the controls, women with stage II periodontitis who underwent HRT had significantly lower CAL and ABH and higher BMD in the second year. The incidence of at least one site with CAL increase ≥1 mm between baseline and 2 years was significantly lower in the HRT group than in the control group in women with stage II periodontitis. In addition, HRT was significantly associated with a decrease in SBI, BOP, IL-6, and TNF-α in the first year and with a decrease in CAL, SBI, BOP, IL-6, and ABH and an increase in BMD in the second year. CONCLUSIONS: In postmenopausal women with stage II periodontitis, HRT is associated with the alleviation of inflammation within two years and the remission of alveolar bone loss in the second year. HRT appears to decrease the incidence of CAL increase ≥1 mm within 2 years in women with periodontitis by inhibiting inflammation and alveolar bone loss.

Adsorption and Desorption of Steroid Hormones by Microplastics in Seawater.

This study evaluated the adsorption and desorption of 17ß-estradiol (E2) and 17α-ethynylestradiol (EE2) on microplastics in seawater. The effects of microplastic materials and particle sizes on adsorption of E2 and EE2 were explored. Moreover, effects of salinity, pH, humic acid (HA) concentrations, and initial E2/EE2 concentrations on adsorption were also discussed. Increase in salinity, HA concentration, and initial E2/EE2 concentration would enhance adsorption of E2/EE2 on microplastics. Adsorption capacity of E2/EE2 firstly increased to reach the highest at pH of 8.0 and then decreased when pH further increased. Pseudo-second-order kinetics better fitted adsorption data of E2 while pseudo-first-order model yielded better fitting results for EE2. Freundlich isotherm was better to fit the adsorption data of E2 while Langmuir isotherm yielded better fitting results for EE2. Desorption capacity of E2/EE2 on microplastics was over 40% of its adsorption capacity. This study provides new insights on microplastics and endocrine disrupting chemicals.

Amplified fluorescent sensing of DNA using graphene oxide and a conjugated cationic polymer.

We explore the interactions between a fluorescein (FAM)-labeled single-stranded DNA (P), graphene oxide (GO), and a cationic conjugated polymer, poly [(9,9-bis(6'-N,N,N-trimethylammonium)hexyl)-fluorenylene phenylene dibromide] (PFP). It is found that the fluorescence change of P-GO-PFP system is dependent on the addition order of P and PFP. When adding PFP into P/GO complex, the fluorescence resonance energy transfer (FRET) from PFP to P is inefficient. If P is added to PFP/GO complex, efficient FRET is obtained. This may be attributed to the equal binding ability for P and PFP to GO. The results of time-resolved fluorescence and fluorescence anisotropy support the different fluorescent response under different addition order of P and PFP to GO. Based on the above phenomenon, we demonstrate a method to reduce the high background signal of a traditional PFP-based DNA sensor by introducing GO. In comparison to the use of single PFP, the combination of PFP with GO-based method shows enhanced sensitivity with a detection limit as low as 40 pM for target DNA detection.

Effect of titanium preoxidation on wrought pure titanium to ceramic bond strength.

STATEMENT OF PROBLEM: The creation of high bond strength between machined computer-manufactured pure titanium and porcelain remains a problem. However, machined titanium does not form the thick titanium oxide film found in cast titanium. PURPOSE: The purpose of this study was to investigate the effects of different preoxidation treatments on the bond strength of a machined pure titanium ceramic system. MATERIAL AND METHODS: Specimens of commercially pure titanium (25 × 3 × 0.5 mm) were divided equally into 6 groups (n=8), which received different preoxidation treatments (3 hour natural oxidation; 600°C, 650°C, 700°C, 750°C, and 800°C for 3 minutes). Bond strengths were evaluated by using a 3-point bend test. The results were analyzed by using 1-way ANOVA and the least significant difference test. Twelve additional specimens of commercially pure titanium (15 × 3 × 0.5 mm) were cut for interface observation and divided equally into 6 groups that received the preoxidation treatments described previously. Scanning electron microscopy and energy dispersive spectrum were used to observe microscopic features of the interface between Ti and ceramic. RESULTS: The bond strength values of the 6 groups ranged from 23.72 ±2.53 MPa to 36.99 ±3.92 MPa, with significant differences (P<.05). The specimen that received 750°C preoxidation had the highest bond strength. The main interface elements of the 6 groups were O, Si, Ti, Sn, Al, Na, and K. Ti showed a sigmoidal diffusion curve in each group, and Si showed a sigmoidal diffusion curve in most groups. Sn was enriched in each group's interface. CONCLUSIONS: Preoxidation under vacuum before porcelain firing can effectively improve the bond strength of machined pure titanium-porcelain systems.

[Relationship between G6PD deficiency and hand-foot-mouth disease induced by enterovirus 71].

OBJECTIVE: To study the influence of glucose-6-phosphate dehydrogenase (G6PD) deficiency on hand-foot-mouth disease (HFMD) induced by enterovirus 71 (EV71) , and possible mechanisms. METHODS: A total of 220 boys with HFMD induced by EV71 were classified into two groups based on disease severity: mild/moderate (n=145) and severe HFMD groups (n=75), and 132 healthy boys were selected as the control group. The activity of G6PD and levels of reduced glutathione (GSH) and malonaldehyde (MDA) in blood were measured using the automatic biochemical analyzer. RESULTS: The percentage of G6PD deficiency cases in the severe HFMD group was significantly higher than in the control group (P<0.0125). In the severe HFMD group, the durations of fever, mental abnormality, limb trembling and hospital stay were significantly longer in children with G6PD deficiency than in those with normal G6PD activity (P<0.05). In the acute and recovery stages, patients in the mild/moderate and severe HFMD groups had significantly lower GSH levels and G6PD activity and significantly higher MDA levels compared with those in the control group (P<0.05). In the acute stage, children in the mild/moderate and severe HFMD groups with G6PD deficiency had significantly lower GSH levels and significantly higher MDA levels compared with those with normal G6PD activity (P<0.01). In the acute and recovery stages, GSH level in children with HFMD was positively correlated with G6PD activity (r=0.61, P<0.01; r=0.58, P<0.01), and in the acute stage, MDA level was negatively correlated with G6PD activity (r=-0.29, P<0.01). CONCLUSIONS: G6PD deficiency is probably a predisposing factor for HFMD induced by EV71 and may aggravate the patient's condition. Its mechanism might be related to oxidative stress.

Rubber and pulp plantations represent a double threat to Hainan's natural tropical forests.

Hainan, the largest tropical island in China, belongs to the Indo-Burma biodiversity hotspot and harbors large areas of tropical forests, particularly in the uplands. The Changhua watershed is the cradle of Hainan's main river and a center of endemism for plants and birds. The watershed contains great habitat diversity and is an important conservation area. We analyzed the impact of rubber and pulp plantations on the distribution and area of tropical forest in the watershed, using remote sensing analysis of Landsat images from 1988, 1995 and 2005. From 1988 to 1995, natural forest increased in area (979-1040 sq km) but decreased rapidly (763 sq km) over the next decade. Rubber plantations increased steadily through the study period while pulp plantations appeared after 1995 but occupied 152 sq km by 2005. Rubber and pulp plantations displace different types of natural forest and do not replace one another. Because pulp is not as profitable as rubber and existing pulp processing capacity greatly exceeds local supply, considerable pressure exists on remaining upland forests. We recommend for future management that these plantation forests be reclassified as 'industrial', making a clear policy distinction between natural and industrial forestry. Additionally, the local government should work to enforce existing laws preventing forest conversion on marginal and protected areas.

[Rapid method for determination of furfural and 5-hydroxymethyl furfural in pre-extraction stream of biomass using UV spectroscopy].

The present paper reports a rapid method for the determination of furfural (F) and 5-hydroxymethyl furfural (HMF) in pre-extraction liquors of lignocellulosic biomass based on UV spectroscopy. In a concentrated acetic acid medium, F and HMF have an isosbestic point at 276 nm. It was found that the acidic soluble lignin in the pre-extraction sample is the major interference species in the F and HMF spectroscopic quantification However, only acidic soluble lignins have the absorption at the wavelengths above 325 nm. Based on the absorption of the acidic soluble lignins at 325 nm, their absorptions at either F or HMF absorbed wavelengths can be determined. Thus, with a simple triple-wavelength technique, both F and HMF in the pre-extraction liquors of lignocellulosic biomass can be quantified based on the spectroscopic measurement at the isosbestic point wavelength (276 nm), maximum absorption wavelength of F (272 nm) and the acid soluble lignin absorbed wavelength (325 nm). The present method does not require the hazardous organic compounds (such as phenolic compounds etc.) acting as a color reagent in the experiment. It is not only simple and rapid, but also has a good measurement precision and accuracy, with the relative standard deviations of 3.02% and 2.72%, and recoveries of 95%-107% and 96%-101%, respectively, in the F and HMF quantification. The present method is suitable for use in the research on pre-extraction hemicellulose of the lignocellulosic biomass in bio-refinery area in order to achieve a high selective sugar conversion.

The sensitive "Turn-on" fluorescence platform of ascorbic acid based on conjugated polymer nanoparticles.

Ascorbic acid (AA) is very important for maintaining the normal physiological processes of the organism. In order to overcome the shortcomings of existing methods, such as lower sensitivity, complex operations and expensive instruments, it is urgent to develop a simple and rapid method for the determination of AA in the field of food and pharmaceutical preparations. Conjugated polymer nanoparticles (CPNs) have lately aroused wide concerns because of excellent optical properties, biocompatibility and stability. In our work, a CPNsPBOC-COOH fluorescence platform based on Poly [3-{2,5-bis (2-ethyl-hexyloxy)]-phenyl}-vinyl}-9-octyl-carbazole] (PBOC) and Polystyrene-maleic anhydride (PSMA), was prepared for the quantitative detection of AA. Experimental results were showed that this platform was highly selective and sensitive to AA. The concentration of AA detected by the fluorescence platform has a linear relationship in the range of 0.57-17.10 µM. The limit of detection (LOD) is 10 nM, which is lower than other methods reported. More interestingly, the fluorescence of CPNsPBOC-COOH can be controlled by logic gates with Fe3+ and AA. Finally, the designed fluorescence platform has been successfully applied to the analysis of AA in actual samples (vitamin C tablets, mouse serum and plasma), indicating the designed platform with a good feasibility.

Occurrence and spatial distribution of antibiotic resistance genes in the Bohai Sea and Yellow Sea areas, China.

Rapid development of Bohai and Yellow Sea Economic Rim has led to the concern of emerging contamination of marine environments. This study investigated the spatial distribution of antibiotic resistance genes (ARGs) in Bohai and Yellow Sea areas. A large scale sampling from Bohai Sea, Yellow Sea and the major cities along the coastline from the mouth of Yalu River to the Yangtze River was performed. The spatial distribution of target ARGs based on the absolute abundances was in the trend of river water ≈ coastal water > the Bohai Sea > the Yellow Sea, inshore > offshore and inner bay > bay mouth. The total absolute abundances of selected ARGs in the coastal waters (1.23 × 104-3.94 × 105 copies/mL) were about 1-4 orders of magnitude higher than those in the sea (21.1-8.00 × 103 copies/mL). The abundances of ARGs fluctuated greatly in the Yellow Sea and the coastal areas. Sulfonamide resistance genes hold the highest abundances in the Bohai and Yellow Sea (up to 2.13 × 103 copies/mL of sul1 and 6.23 × 103 copies/mL of sul2), followed by tetracycline and quinolone resistance genes, while qnrA hold the highest abundances in coastal areas (up to 3.66 × 105 copies/mL). The distribution coefficients of target genes between sediments and corresponding water samples were more than 1.0 in the majority of different aquatic systems. According to the principle component analysis and redundancy analysis, water samples collected from the sea clustered together while those from the coastal zone and rivers were separated. Ammonium and nitrate played important roles in the distribution and variation of ARGs. Co-occurrence network analysis revealed that the potential multi-antibiotics resistant bacteria were detected with higher abundances in the Yellow Sea than in the Bohai Sea. These observations provided a comprehensive new insight into the pollution status of ARGs in the Bohai and Yellow Sea areas.

Changes of cytoskeletal proteins in nerve tissues and serum of rats treated with 2,5-hexanedione.

To investigate the mechanisms and biomarker of the neuropathy induced by 2,5-hexanedione (HD), male Wistar rats were administrated HD at dosage of 200 or 400mg/kg for 8 weeks (five-times per week). All rats were sacrificed after 8 weeks of treatment and the cerebrum cortex (CC), spinal cord (SC) and sciatic nerves (SN) were dissected, homogenized and used for the determination of cytoskeletal proteins by western blotting. The levels of neurofilaments (NFs) subunits (NF-L, NF-M and NF-H) in nerve tissues of 200 and 400mg/kg HD rats significantly decreased in both the supernatant and pellet fractions. Furthermore, significant negative correlations between NFs levels and gait abnormality were observed. As for microtubule (MT) and microfilament (MF) proteins, the levels of alpha-tubulin, beta-tubulin and beta-actin in the supernatant and pellet fraction of SN significantly decreased in 200 and 400mg/kg HD rats and correlated negatively with gait abnormality. However, the contents of MT and MF proteins in CC and SC were inconsistently affected and had no significant correlation with gait abnormality. The levels of NF-L and NF-H in serum significantly increased, while NF-M, alpha-tubulin, beta-tubulin and beta-actin contents remain unchanged. A significant positive correlation (R=0.9427, P<0.01) was observed between gait abnormality and NF-H level in serum as the intoxication went on. These findings suggested that HD intoxication resulted in a progressive decline of cytoskeletal protein contents, which might be relevant to the mechanisms of HD-induced neuropathy. NF-H was the most sensitive index, which may serve as a good indicator for neurotoxicity of n-hexane or HD.

Association of polymorphisms in key Th-17 immune response genes with HBeAg-positive chronic hepatitis B susceptibility and response to PEG-IFNa-2α.

This study aims to investigate effects of polymorphisms in key Th-17 immune response genes on the susceptibility to HBeAg-positive (HBeAg+) chronic hepatitis B (CHB) and response to PEG-IFNa-2α. A total of 139 patients with HBeAg+ CHB treated with PEG-IFNa-2α and 145 healthy controls were enrolled to explore the association between IL-17A, IL-17F, IL-21 and IL-23R polymorphisms and HBeAg+ CHB susceptibility, as well as treatment efficacies. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. IL-17A rs4711998 and IL-17F rs763780 may affect susceptibility to HBeAg+ CHB and response to PEG-IFNa-2α treatment. The T allele of IL-21 rs12508721 may lower HBeAg+ CHB susceptibility but enhance PEG-IFNa-2α response, and the GA genotype and the A allele of IL-23R rs11209026 may reduce the susceptibility to HBeAg+ CHB. Th17-related gene polymorphisms were linked to HBeAg+ CHB susceptibility, and rs4711998, rs763780 and rs12508721 were associated with sustained responses to PEG-IFNa-2α.

Lysosomal ATP imaging in living cells by a water-soluble cationic polythiophene derivative.

Lysosomes in astrocytes and microglia can release ATP as the signaling molecule for the cells through ca(2+)-dependent exocytosis in response to various stimuli. At present, fluorescent probes that can detect ATP in lysosomes have not been reported. In this work, we have developed a new water-soluble cationic polythiophene derivative that can be specifically localized in lysosomes and can be utilized as a fluorescent probe to sense ATP in cells. PEMTEI exhibits high selectivity and sensitivity to ATP at physiological pH values and the detection limit of ATP is as low as 10(-11)M. The probe has low cytotoxicity, good permeability and high photostability in living cells and has been applied successfully to real-time monitoring of the change in concentrations of ATP in lysosomes though fluorescence microscopy. We also demonstrated that lysosomes in Hela cells can release ATP through Ca(2+)-dependent exocytosis in response to drug stimuli.

Enhanced cardioprotective effects mediated by plasmid containing the short-hairpin RNA of angiotensin converting enzyme with a biodegradable hydrogel after myocardial infarction.

The expression of foreign gene was enhanced and prolonged by sustained releasing a target gene to cells from biodegradable dextran-poly(e-caprolactone)-2-hydroxylethylmethacrylate-poly(N-isopropylacrylamide) (Dex-PCL-HEMA/PNIPAAm) hydrogel in vitro. Moreover, we have demonstrated that injection of the same hydrogel improved post-infarct ventricular remodeling. Therefore, we hypothesized that intramyocardial injection of plasmid containing the short-hairpin RNA (shRNA) of angiotensin converting enzyme (ACE) with the same hydrogel enhances the cardioprotective effects superior to either alone or after rat myocardial infarction (MI). In this study, equal volume of phosphate-buffered solution (PBS), 10 µg ACE-shRNA plasmids, hydrogel containing 10 µg negative control ACE-shRNA plasmids and hydrogel containing 10 µg ACE-shRNA plasmids were shortly injected into the infarct area of rats after MI, respectively. We found that ACE-shRNA plasmid-loaded hydrogel extended the duration of gene expression in vivo. Moreover, it was shown that direct intramyocardial injection of ACE-shRNA plasmid-loaded hydrogel significantly decreased the expression of local ACE expression, inhibited cell apoptosis, reduced infarct size, and improved cardiac function compared with the injection of either alone 30 days after MI in rats. These results suggest that injection of ACE-shRNA plasmid-loaded hydrogel into impaired myocardium obtains more cardioprotective effects than either alone in rat with MI by prolonging the gene silencing of ACE. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3452-3458, 2014.

[Clinical study of submental artery island myocutaneous flap for reconstruction of oral and maxillofacial defects following operation].

OBJECTIVE: To evaluate the outcome and indication of the reconstruction of oral and maxillofacial postoperative defects by submental artery island myocutaneous flaps. METHODS: Sixty eight cases with the reconstruction of oral and maxillofacial defects by submental artery island myocutaneous flaps from January 2006 to May 2010 were analysed retrospectively. Primary lesions included carcinomas originating from tongue (28 cases), palate (13 cases), mouth floor (9 cases), gingiva (4 cases), buccal mucosa (6 cases), lip (3 cases), and other malignant or benign tumors (5 cases). The ages ranged from 25 to 84 years (mean 58 years); 47 males and 21 females. The sizes of skin paddle varied from a minimum of 4 cm × 4 cm to a maximum of 15 cm × 10 cm. RESULTS: Of the 68 flaps, 62 were survival, 4 had partial necrosis but healed with treatments, and 2 failed due to complete necrosis. Appearance and functions of recipient sites were satisfactory. The followed-up time was 3 - 24 months, local recurrence occurred in 5 cases and cervical lymph node metastases were found in 15 patients. CONCLUSION: Submental island flap is reliable for the reconstruction of postoperative defects in early oral cancer without regional lymph node metastasis or in benign tumor.

Extraction, partial characterization, and storage stability of ß-glucosidase from propolis.

Extraction and assay conditions for ß-glucosidase from propolis were optimized. Highest enzyme activity was obtained in a citric acid-disodium hydrogen phosphate buffer at pH 6.0 with 2.5% insoluble polyvinylpyrrolidone at incubation temperature of 57 °C. ß-Glucosidase activities were found in all freshly harvested propolis while ß-glucosidase activities were scarcely present in the randomly bought propolis. Propolis was stored at -20 °C and 4 °C for 3 mo with almost no loss of ß-glucosidase activity, but at room temperature the activity decreased exponentially with the increase of storage time. These results indicated that the activity of ß-glucosidase could be a candidate for propolis-freshness index. ß-Glucosidase from propolis was capable of hydrolyzing p-nitrophenyl-ß-D-glucoside and p-nitrophenyl-ß-D-galactoside, but lacked activity toward p-nitrophenyl-ß-D-glucuronide, p-nitrophenyl-ß-D-cellobioside, amygdalin, cellobiose, and gentiobiose. These results were consistent with the hypothesis that flavonoid glucosides were hydrolyzed by ß-glucosidase during propolis collection and processing and provided a possible explanation for why some flavonoid biosides (that is, rutin and isorhamnetin-3-O-rutinoside) exist in propolis. Practical Application: ß-Glucosidase activity was detected and partial characterization of the enzyme was determined in propolis. The enzyme activity decreased exponentially with the increase of storage time at room temperature, which suggested that the activity of ß-glucosidase could be regarded as a freshness index of propolis. The research will be useful for studying the chemical constituents of propolis.

[Effect of different heat treatment on the bonding strength of porcelain and Co-Cr alloy].

PURPOSE: To investigate and compare the effect of different heat treatment on the metal- ceramic bonding strength and the interfacial microstructure of the Co-Cr alloy. METHODS: Thirty specimens were made according to ISO 9693,and then divided into 3 groups (n=10) through the measurements .Group A(degassed 60s):degassed and then maintained 60s in 980 degrees centigrade Group B(degassed 60s and preoxidation 60s): degassed and maintained 60s in 980 degrees centigrade, then were maintained continuously for 60s in 980 degrees centigrade after re-gassed,Group C(degassed 120s): degassed and maintained 120s in 980 degrees centigrade. The bonding strengths of the three groups were evaluated through three point bending test. Six specimens divided into 3 group were made in the same method to observe the metal-ceramic interface through scanning electronic microscope(SEM) and energy dispersive spectrum(EDS).The bonding strength data were analyzed using ANOVA and Bonferroni's test by SPSS13.0 software package. RESULTS: The mean value of bonding strength was (39.03±2.70)MPa for group A, (34.43±2.36)MPa for group B, (31.65±1.49)MPa for group C, respectively. There were significant difference between every two groups (P<0.05). SEM demonstrated that the width of interfacial transition layer was 12.3-16.4µm in group A, 15.2-21.8µm in group B and 26.3-32.2µm in group C. CONCLUSIONS: Higher metal-ceramic bonding strength for Co-Cr alloy will be formed under the situation of degassed,and maintained 60s in 980 degrees centigrade ; while extending degassed time, prolonging the heat maintained time and preoxidation after degassing will reduce metal-ceramic bonding strength.