[Gene polymorphisms of cytochrome B-245 alpha chain (CYBA) and cholesteryl ester transfer protein (CETP) and susceptibility to generalized aggressive periodontitis].

OBJECTIVE: To explore the correlation of cytochrome B-245 alpha chain (CYBA) rs4673 and cholesteryl ester transfer protein (CETP) rs12720922 polymorphisms with the susceptibility of gene-ralized aggressive periodontitis (GAgP). METHODS: The study was a case-control trial. A total of 372 GAgP patients and 133 periodontally healthy controls were recruited. The CYBA rs4673 and CETP rs12720922 polymorphisms were detected by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Logistic regression models were used to analyze the correlation of CYBA rs4673 and CETP rs12720922 variants with the susceptibility of GAgP. The interaction between the two gene polymorphisms to the susceptibility of GAgP was analyzed by the likelihood ratio test. The interaction model adopted was the multiplication model. RESULTS: The mean age of GAgP group and control group was (27.5±5.2) years and (28.8±7.1) years respectively. There was significant difference in age between the two groups (P < 0.05). The gender distribution (male/female) was 152/220 and 53/80 respectively, and there was no significant difference between GAgP group and controls (P>0.05). For CYBA rs4673, the frequency of CT/TT genotype in the GAgP group was significantly higher than that in the controls [18.0% (66/366) vs. 10.6% (14/132), P < 0.05]. After adjusting age and gender, the individuals with CT/TT genotype had a higher risk of GAgP (OR=1.86, 95%CI: 1.01-3.45, P < 0.05), compared with CC genotype. There was no statistically significant difference in distributions of the CETP rs12720922 genotypes (GG, AA/AG) between GAgP patients and healthy controls (P>0.05). A significant interaction between CYBA rs4673 and CETP rs12720922 in the susceptibility to GAgP was observed. The GAgP risk of the individuals with CYBA rs4673 CT/TT and CETP rs12720922 GG genotypes was significantly increased (OR=3.25, 95%CI: 1.36-7.75, P < 0.01), compared with those carrying CC and AA/AG genotypes. CONCLUSION: CYBA rs4673 CT/TT genotype is associated with GAgP susceptibility. There is a significant interaction between CYBA rs4673 CT/TT genotype and CETP rs12720922 GG genotype in the susceptibility of GAgP.

[Clinical evaluation of periodontal-orthodontic treatment in patients with aggressive periodontitis and malocclusion].

OBJECTIVE: To evaluate the clinical effect and safety of periodontal-orthodontic treatment in patients with aggressive periodontitis (AgP) and malocclusion. METHODS: A retrospective analysis was conducted in 25 AgP patients, who had received periodontal-orthodontic treatment in Peking University School and Hospital of Stomatology. Clinical indexes, including probing depth (PD), bleeding index (BI) and percentage of sites with bleeding on probing (BOP%) were evaluated at three time points: Baseline (T0); active periodontal treatment finished and before orthodontic treatment (T1); and after orthodontic treatment (T2). Also changes of ratio of the residual alveolar bone height (RBH) and the occurrence of root resorption were evaluated by periapical radiographs. RESULTS: (1) Compared with T0, all the clinical parameters including PD, BI, BOP% and percentage of sites with PD>3 mm were significantly improved (P<0.001). (2) Significant difference was observed in the average RBH between T0 (68.37%±15.60% and T2 (70.27%±14.23%). RBH in upper incisors [(58.79%±16.71% at T0, 65.54% (55.74%, 78.13%) at T2], upper canines [77.62% (66.06%, 87.17%) at T0, 79.57% (69.75%, 86.52%) at T2] and upper molars [74.30% (61.69%, 84.45%) at T0, 76.76% (68.12%, 85.09%) at T2] showed significant increase (P<0.05). (3) After orthodontic treatment, varying degrees of root resorption occurred in (23.94%±13.45%) of teeth per capita, among which the lower and upper incisors showed the highest incidence (68.48% and 65.31% in homogeneous teeth, respectively). CONCLUSION: After active periodontal treatment, orthodontic treatment in AgP patients had not aggravated inflammation and alveolar bone resorption; root resorption occurred in two-thirds of incisors approximately.

[Histomorphometric evaluation of ridge preservation after molar tooth extraction].

OBJECTIVE: To evaluate bone formation in human extraction sockets with absorbed surrounding walls augmented with Bio-Oss and Bio-Gide after a 6-month healing period by histologic and histomorphometric analyses. METHODS: Six fresh molar tooth extraction sockets in 6 patients who required periodontally compromised moral tooth extraction were included in this study. The six fresh extraction sockets were grafted with Bio-Oss particle covered with Bio-Gide. The 2.8 mm×6.0 mm cylindric bone specimens were taken from the graft sites with aid of stent 6 months after the surgery. Histologic and histomorphometric analyses were performed. RESULTS: The histological results showed Bio-Oss particles were easily distinguished from the newly formed bone, small amounts of new bone were formed among the Bio-Oss particles, large amounts of connective tissue were found. Intimate contact between the newly formed bone and the small part of Bio-Oss particles was present. All the biopsy cylinders measurement demonstrated a high inter-individual variability in the percentage of the bone, connective tissues and Bio-Oss particles. The new bone occupied 11.54% (0-28.40%) of the total area; the connective tissues were 53.42% (34.08%-74.59%) and the Bio-Oss particles were 35.04% (13.92%-50.87%). The percentage of the particles, which were in contact with bone tissues, amounted to 20.13% (0-48.50%). CONCLUSION: Sites grafted with Bio-Oss particles covered with Bio-Gide were comprised of connective tissues and small amounts of newly formed bone surrounding the graft particles.

Associations of apolipoprotein E and low-density lipoprotein receptor-related protein 5 polymorphisms with dyslipidemia and generalized aggressive periodontitis in a Chinese population.

BACKGROUND AND OBJECTIVE: Dyslipidemia is associated with aggressive periodontitis, a condition characterized by the rapid destruction of the periodontium. Apolipoprotein E (APOE) and low-density lipoprotein receptor-related protein 5 (LRP5) are involved in immunomodulation and inflammatory activity. We evaluated the association of LRP5 and APOE polymorphisms with serum lipid concentrations and generalized aggressive periodontitis within a Chinese population. MATERIAL AND METHODS: Mean serum lipid concentrations were compared across LRP5 and APOE polymorphisms, among cases (n = 185) and controls (n = 138). Multivariable logistic regression was used to evaluate the independent and combined associations of LRP5 and APOE polymorphisms with generalized aggressive periodontitis. RESULTS: Compared with controls, individuals with generalized aggressive periodontitis exhibited significantly lower serum total cholesterol (TC) and lower high-density lipoprotein cholesterol (HDL-c). Individuals with LRP5 polymorphisms (rs682429-AA or rs312016-GG) exhibited higher TC, higher HDL-c and decreased odds for generalized aggressive periodontitis. Haplotype (A-G), determined by rs682429 and rs312016, was also associated with decreased odds for generalized aggressive periodontitis. Furthermore, individuals with the combined polymorphisms (LRP5-rs682429-AA and APOE-rs429358-CC/CT) had higher levels of low-density lipoprotein cholesterol, higher levels of TC and decreased odds for generalized aggressive periodontitis. CONCLUSION: Independently or combined with APOE, LRP5 polymorphisms may lead to dyslipidemia and are associated with generalized aggressive periodontitis. Dyslipidemia may be a risk indicator for generalized aggressive periodontitis in the Chinese population. Furthermore, two LRP5 polymorphisms (rs682429 and rs312016) might be useful for identifying subjects at higher risk of generalized aggressive periodontitis.

Effect of non-surgical periodontal treatment on short chain fatty acid levels in gingival crevicular fluid of patients with generalized aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Short chain fatty acids (SCFAs) play important roles in periodontal diseases. However, the concentrations of SCFAs in gingival crevicular fluid of patients with aggressive periodontitis are not known. The aim of this intervention study was to investigate the influences of non-surgical periodontal therapy on levels of SCFAs in the gingival crevicular fluid of patients with generalized aggressive periodontitis (G-AgP), and analyze the concentrations of SCFAs in sites with or without the detected putative periodontal pathogens. MATERIAL AND METHODS: Eighty gingival crevicular fluid samples (four per subject) were collected on filter paper strips from patients with G-AgP (n = 20; mean age 24.5 years), before and at 2 wk, 2, 4 and 6 mo after non-surgical periodontal treatment. Eighty gingival crevicular fluid samples (four per subject) were collected from periodontally healthy controls (n = 20; mean age 26.2 years). Concentrations of formic acid, succinic acid, acetic acid, lactic acid, propionic acid, butyric acid and isovaleric acid from the supernatant of gingival crevicular fluid samples were measured by high performance capillary electrophoresis. Porphyromonas gingivalis, Treponema denticola, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Fusobacterium nucleatum from the precipitate of the same pretreatment samples of gingival crevicular fluids were analyzed by polymerase chain reaction amplification. RESULTS: The clinical parameters of patients with G-AgP during the 6 mo after non-surgical periodontal treatment were improved remarkably. The formic acid concentration increased significantly after treatment; the level of formic acid was lower in the P. gingivalis-, T. denticola-, P. intermedia- or F. nucleatum-positive sites compared with the negative sites. The concentrations of acetic acid, propionic acid and butyric acid reduced significantly after treatment and reached the lowest level at 2 wk post-treatment, although showed a tendency to increase after 2 mo post-treatment, and the three SCFA levels were significantly higher in P. gingivalis-, T. denticola-, P. intermedia- or F. nucleatum-positive sites compared with those in the negative sites. CONCLUSION: Non-surgical periodontal treatment resulted in a significant decrease of acetic acid, propionic acid, butyric acid levels and increase of formic acid level in gingival crevicular fluids in patients with G-AgP, accompanied by improvement in clinical parameters. A marked lower level of formic acid, as well as higher levels of acetic acid, propionic acid and butyric acid in gingival crevicular fluid of patients with G-AgP was consistent with periodontal pathogen infection.

Elevation of vitamin D-binding protein levels in the plasma of patients with generalized aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Vitamin D-binding protein (DBP) is a multifunctional and highly expressed plasma protein. Among its diverse roles, including those in the immune and inflammatory responses, it is the primary carrier of vitamin D, which has been implicated in periodontitis. We hypothesized that there is a correlation between systemic DBP levels and generalized aggressive periodontitis (GAgP). MATERIAL AND METHODS: Forty-four patients with GAgP and 32 healthy controls were recruited. Clinical parameters were examined, including the mean bleeding index, probing depth, attachment loss and percentage of severely affected sites. Blood chemistry analyses were performed for each subject. Plasma levels of DBP, interleukin-6 (IL-6) and procalcitonin (PCT) were measured using ELISAs, and plasma levels of 25-hydroxy-vitamin D(3) (25(OH)D(3)) were detected using a radioimmunoassay. RESULTS: Significantly higher levels of plasma DBP, IL-6, PCT and 25(OH)D(3), as well as leukocyte counts, neutrophil counts and neutrophil percentages were found in patients with GAgP compared with healthy controls (p < 0.05 for all). Multiple linear regression analysis showed that the plasma DBP levels were significantly correlated with GAgP, plasma PCT levels and smoking status (p < 0.05 for all). In the GAgP group, the plasma DBP levels in smokers were significantly higher than those in nonsmokers (p < 0.001). CONCLUSION: Elevated plasma vitamin DBP levels are associated with GAgP.

Clinical outcomes of keratinized mucosa augmentation in jaws reconstructed with fibula or iliac bone flaps.

This prospective study was undertaken to evaluate the treatment outcomes of keratinized mucosa augmentation (KMA) on the buccal and palatal/lingual sides of implants in jaws reconstructed after oncological surgery. Forty-two implants in 12 patients whose jaws had been reconstructed with a fibula or iliac bone flap were included. KMA was performed at 3 months after implant placement; this included an apically displaced partial-thickness flap and a free gingival graft (FGG) around the implants to increase the keratinized mucosa width (KMW). Patients were followed up for at least 6 months post-surgery. KMW, shrinkage, and patient pain and discomfort measured on a visual analogue scale were analysed. A histological analysis was performed of tissue epithelium from two patients. The results showed that KMW was >2 mm on both the buccal and palatal/lingual sides during follow-up. Before surgery, histological analysis showed epithelium with no epithelial spikes; normal keratinized epithelial spikes were observed at 8 weeks after KMA. Greater KMW was observed around implants in reconstructed maxillae than around those in reconstructed mandibles (P < 0.001). Patients felt more pain at the donor site than at the recipient site during the first 3 days post-surgery. KMA with FGG was predictable in reconstructed jaws and may help maintain the long-term stability of implants.

Analysis of plasma calprotectin and polymorphisms of S100A8 in patients with aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Calprotectin is an important proinflammatory mediator in various inflammatory diseases and is composed of two subunits (S100A8 and S100A9). However, the level of calprotectin in plasma of patients with aggressive periodontitis and its relationship with gene polymorphisms of S100A8 are unclear. MATERIAL AND METHODS: The plasma concentrations of calprotectin were measured, using an enzyme immunoassay, in 139 patients with aggressive periodontitis and in 88 periodontally healthy control subjects. These patients were genotyped for the rs3795391 and rs3806232 polymorphisms of S100A8. RESULTS: The plasma concentration of calprotectin in patients with aggressive periodontitis was significantly higher than in controls (2.17 mg/L vs. 1.72 mg/L, respectively, p = 0.001). The percentage of the AA genotype of S100A8 rs3795391 was significantly higher in patients than in controls (82% vs. 69.3%, respectively, p = 0.027), while the frequency of the allele G was decreased among patients compared with controls (9.6% vs. 16.1%, respectively, p = 0.036), which was especially apparent in men (rs3795391 genotype, p = 0.005; rs3795391 allele, p = 0.015). The mean probing depth in patients carrying the AA genotype was significantly higher than that of patients carrying the GA + GG genotype of two polymorphisms of S100A8 (rs3795391, p = 0.035; rs3806232, p = 0.040), whereas the levels of calprotectin between different genotypes were not significantly different (rs3795391, p = 0.11; rs3806232, p = 0.15). CONCLUSION: These findings indicate that aggressive periodontitis is associated with elevated levels of plasma calprotectin and that gene polymorphisms of S100A8 may influence the susceptibility and severity of aggressive periodontitis.

[Clinical research progress in the treatment of intrabony defect by minimally invasive periodontal surgery].

Minimally invasive surgery develops rapidly in the periodontal treatments, especially in the periodontal regenerative treatment, in recent years. It supplements, to a certain extent, the insufficiency of the conventional periodontal regenerative treatment. The minimally invasive surgery has many advantages such as enhancing the healing process, reducing surgical chair time and minimizing patient discomfort, etc. It has been proved to improve the clinical effect and provide additional benefits compared to conventional approaches. At present, there are many studies on minimally invasive techniques used in tooth extraction or implant placement in China, but there are few reports on the application of periodontal minimally invasive surgical techniques. Thus based on the reviews of the literatures, this article describes the applications, advantages, indications, microsurgical instruments of minimally invasive periodontal surgery on the treatment of intrabony defect, including various minimally invasive surgical procedures. The review also demonstrates the therapeutic effects and research progress of minimally invasive periodontal surgery combined with biomaterials used in the treatments of intrabony defect. The present article may also provide reference for clinicians applying minimally invasive surgeries to treat intrabony defects.

[Effect of systemic use of amoxicillin and metronidazole during mechanical therapy on the periodontal microorganisms in subgingival plaque and saliva of patients with aggressive periodontitis].

Objective: To explore the effect of systemic use of amoxicillin and metronidazole during mechanical therapy on the clinical parameters of the first molars and periodontal microorganisms in subgingival plaque and saliva in patients with generalized aggressive periodontitis (GAgP). Methods: A total of 23 GAgP patients were recruited from Peking University School and Hospital of Stomatology from January 2006 to December 2009 and then randomly divided into two groups according to random number table: 12 patients received scaling and root planning (SRP) only and 11 patients received SRP combined with systemic administration of antibiotics (amoxicillin and metronidazole for a week after supragingival scaling). Clinical examination of periodontal parameters and collection of saliva and pooled subgingival plaque samples from mesial-buccal sites of 4 first molars were performed before initial therapy and 2, 4 and 6 months respectively after mechanical therapy, and saliva samples were also collected 2 weeks after therapy. Eight different periodontal microorganisms were detected in these samples by PCR. In addition, semiquantitative analysis of red complex microorganisms [Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td)] was performed. Results: Both therapies led to significant decrease of the plaque index (PLI), probing depth (PD) and bleeding index (BI) from mesial-buccal sites of first molars. Meanwhile the PD of antibiotics group [(4.21±1.50), (4.00±1.54), (3.84±1.89) mm of 2, 4 and 6 months respectively after therapy] was significantly lower than the SRP group [(5.29±1.27), (5.30±1.34), (4.98±1.36) mm of 2, 4 and 6 months respectively after therapy] at 3 different time points after mechanical therapy (P<0.05). In the antibiotics group, the quantities of Pg, Tf and Td in subgingival plaque samples (the median quantity decreased to 0.0 ng at 2, 4 and 6 months after therapy) and saliva samples (the median quantity of Tf and Td decreased to 0.0 ng at 2, 4 and 6 months after therapy (P<0.05), and the median quantity of Pg decreased to 16.3, 59.6 and 22.4 ng at 2, 4 and 6 months respectively after therapy) significantly decreased at 3 different time points after mechanical therapy compared with before therapy (P<0.05). While in the SRP group, there were no significant changes in the quantities of Tf and Td in saliva at 2, 4 and 6 months after mechanical therapy (P>0.05) , and the quantities of Tf and Td in subgingival plaque significantly decreased only at 2 months after therapy (P<0.05). Conclusions: SRP combined with systemic administration of amoxicillin and metronidazole could achieve greater improvement in PD of first molars and better control of the amounts of red complex microorganisms in the saliva and subgingival plaque of GAgP patients over a 6-month period.

[Interaction analysis between epidermal growth factor and peroxidase proliferators activate receptor-α gene polymorphism and susceptibility to generalized aggressive periodontitis].

Objective: To explore the correlation and interaction between epidermal growth factor (EGF) rs2237051 and peroxidase proliferators activate receptor-α (PPAR-α) rs4253623 polymorphisms and the susceptibility of generalized aggressive periodontitis (GAgP). Methods: Two hundred and nineteen Chinese patients with GAgP were enrolled from the patients of the Department of Periodontology, Peking University School and Hospital of Stomatology from January 2001 to December 2015. The control group comprised 138 periodontally healthy volunteers recruited from the staff and students of the Peking University School and Hospital of Stomatology. The EGF rs2237051 and PPAR-α rs4253623 polymorphisms were genotyped using time-of-flight mass spectrometry. Logistic regression models were conducted to analyze the correlation between the EGF rs2237051 and PPAR-α rs4253623 variants with GAgP. The likelihood ratio test was used to analyze whether there was an interaction between the two polymorphisms in the susceptibility of GAgP. The interaction model adopted was the multiplication model. Results: The mean ages of GAgP group (male:87; female:132) and control group (male: 53; female: 85) were (27.3±4.5) years and (27.1±4.2) years respectively and there was no significant difference in age and gender distribution between the two groups. For EGF rs2237051, the frequency of AA genotype in the GAgP group [49.5% (107/216)] was significantly higher than that in the control group [37.7% (52/138)], and the frequency of AG/GG genotype in the GAgP group [50.5% (109/216)] was significantly lower than that in the control group [62.3% (86/138)](P<0.05). Compared with AA genotype, individuals with AG/GG genotype had a 39% lower risk of GAgP after adjustment of age and gender (OR: 0.61, 95%CI: 0.40-0.95, P<0.05). For PPAR-α rs4253623, the frequency of AA genotype in the GAgP group [76.2% (160/210)] was significantly higher than that in the control group [65.9%(81/123)], and the frequency of AG/GG genotype in the GAgP group [23.8% (50/210)] was significantly lower than that in the control group [34.1%(42/123)] (P<0.05). Compared with AA genotype, individuals with AG/GG genotype had a 40% lower risk of GAgP after adjustment of age and gender (OR: 0.60, 95%CI: 0.36-0.98, P<0.05). EGF rs2237051 and PPAR-α rs4253623 showed a significant interaction in the susceptibility to GAgP. Compared with AA genotype, the risk of GAgP in individuals with both AG/GG genotypes of EGF rs2237051 and PPAR-α rs4253623 was reduced by 66% (OR: 0.34, 95%CI: 0.17-0.66, P<0.01). Conclusions: EGF rs2237051 and PPAR-α rs4253623 are correlated with GAgP susceptibility, and there is a significant interaction between them in the susceptibility of GAgP. The G allele of the two loci has a protective effect on the disease of GAgP.

Elevation of C-reactive protein and interleukin-6 in plasma of patients with aggressive periodontitis.

BACKGROUND AND OBJECTIVE: Systemic levels of C-reactive protein and interleukin-6 have been reported to be elevated in patients with periodontitis compared with periodontally healthy individuals. Most studies included patients with chronic periodontitis and comprised predominantly Caucasians. The aim of this study was to determine the relative levels of C-reactive protein and interleukin-6 in plasma of patients with aggressive periodontitis in China and to examine the relationships between these two inflammatory mediators and clinical parameters, peripheral blood cells and protein variables. MATERIAL AND METHODS: Plasma samples were collected from 84 patients with aggressive periodontitis and from 65 control subjects. Periodontal examination consisted of taking probing depth and attachment loss measurements. The levels of plasma C-reactive protein and interleukin-6 were determined using enzyme-linked immunosorbent assays. RESULTS: The levels of plasma C-reactive protein in patients with aggressive periodontitis were significantly higher than those in control subjects (1.87 vs. 0.52 mg/L). The level of plasma interleukin-6 in patients with aggressive periodontitis was 1.20 pg/mL, higher than that in control subjects (0.08 pg/mL). Multiple linear regression analysis showed that log C-reactive protein was significantly related to severe sites percentage and albumin following correction for age, gender, body mass index and smoking (p = 0.000, p = 0.008, respectively). Log interleukin-6 was found to be significantly correlated with periodontal diagnosis, leukocyte count and level of fasting blood glucose after adjusting for the confounders (p = 0.000, p = 0.009 and p = 0.013, respectively). CONCLUSION: Patients with aggressive periodontitis have significantly elevated levels of plasma C-reactive protein and interleukin-6. These elevated inflammatory factors might potentially increase the risk for cardiovascular events and glucose dysregulation in relatively young individuals.

Family-based association analysis of S100A8 genetic polymorphisms with aggressive periodontitis.

BACKGROUND AND OBJECTIVE: It is known that S100A8, a member of the S100 calcium-binding protein family, is associated with inflammatory diseases, including periodontitis. Our previous population-based study found an association between two polymorphisms, rs3795391 (A > G) and rs3806232 (A > G), in the upstream region of the S100A8 gene and aggressive periodontitis (AgP) in Chinese people. Based on those results, this investigation set out to analyze and corroborate whether the association also exists within families. MATERIAL AND METHODS: Two hundred and four subjects from 73 nuclear families were recruited. All probands and their relatives were diagnosed according to the 1999 classification of periodontal diseases. Anticoagulated peripheral blood samples were collected from all the subjects, and DNA was extracted. The two single nucleotide polymorphisms (SNPs; rs3795391 and rs3806232) were detected and analyzed by standard polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Analysis of genotype/allele was performed by Family-Based Association Test (FBAT) software ( http://www.biostat.harvard.edu/~fbat/default.html). RESULTS: There was a statistically significant association of the SNP rs3795391 with AgP in the additive genetic model (chi(2) = 3.9836, d.f. = 1, p = 0.0459). Allele A showed significantly preferential transmission to the AgP affected individuals (Z = 1.996, p = 0.0459). The other SNP, rs3806232, showed no significant results in all models. CONCLUSIONS: This family-based association study supports the previous findings that SNP rs3795391 (A > G) of the S100A8 gene might contribute to AgP susceptibility. This is, to our knowledge, the first investigation about AgP using FBAT in genetic analysis.

An optimal rice-based oral rehydration solution: the effect of different concentrations of amylase on production of short chain polymers of glucose.

As part of a plan to develop a rice-based oral rehydration solution containing short polymers of glucose instead of glucose, we determined the concentration of amylase that would yield the largest amount of short chain polymers. Thai rice (25 g) was boiled with 500 ml of distilled water for 30 min. Of 200 ml supernatant rice water obtained, 100 ml were digested with different amounts of amylase after cooling to 50 degrees C for 60 min, boiled for 5 min, and centrifuged (10,000 g, 25 degrees C) for 60 min. The resulting supernatant (80 ml) was freeze-dried; 1.75 g of the powder obtained were dissolved in 3.5 ml of water, passed through a Bio-Gel P2 column to separate short chain polymers (2-9 molecules of glucose) and long chain polymers (> 9 molecules of glucose), which were identified by spectrophotometry (lambda = 190 nm) or by high performance liquid chromatography. Ten mg of amylase (equivalent to 12,000 modified Wohlgemath units) per 100 ml of rice water was optimal for the production of short polymers of glucose from rice.

In vitro investigation of blood compatibility of Ti with oxide layers of rutile structure.

Structure characteristics of titanium oxide layer on titanium matrix were investigated by Rutherford Backscattering Spectroscopy (RBS), Auger Electron Spectroscopy (AES) and X-ray diffraction. It has been identified that the titanium oxide layers had rutile structure. The blood compatibility of the titanium oxide layers of different thickness was studied by blood clotting time measurement. It was shown that as the thickness of the titanium oxide layers increased, blood compatibility of these layers was obviously improved.

An investigation of the composite resin/porcelain interface.

Failures at composite resin/porcelain interfaces under shear-like loading were examined. Porcelain surfaces were treated with hydrofluoric acid and/or one of two silane coupling agents, using two different composite resin cements. The results showed that after seven days storage, bond strengths of specimens which had undergone porcelain surface treatment were greater than the cohesive strength of the porcelain itself, resulting in brittle fracture of the porcelain. The diluted restorative composite resin performed as well as the commercial composite resin cement. Silane pretreatment of porcelain was important as the bond strength of etched/silane primed specimens was significantly higher than the etched only specimens. However, one primer appeared to be more efficient than the other in bond promotion. Some explanations for the differences in bond strengths are offered.

[Effects of tea polyphenol on blood lipid and antioxidation in vivo in aged rats].

OBJECTIVE: To study the ability of tea polyphenol to lowering blood lipid and antioxidation in the aged rats. METHODS: The SD rats were divided into three groups, i.e., control group and two trial groups fed with 1% and 2% tea polyphenol for six weeks, respectively. RESULTS: Tea polyphenol could reduce serum level of lipid peroxide and increase the ratio of high-density lipoprotein cholesterol (HDL-C) to total cholesterol (TC), and significantly lower serum level of lipid peroxide in rats. Activities of superoxide dismutase in red blood cells of rats fed with 2% tea polyphenol were significantly higher than those in control ones. CONCLUSION: Tea polyphenol can enhance antioxidation in vivo in the aged rats.

Insulin resistance is a major determinant of sustained virological response in genotype 1 chronic hepatitis C patients receiving peginterferon alpha-2b plus ribavirin.

BACKGROUND: Cross-sectional studies suggest insulin resistance is strongly associated with hepatic steatosis and fibrosis in patients with chronic hepatitis C (CHC), which might affect the efficacy of antiviral therapy. Aim To investigate retrospectively the impact of insulin resistance on treatment response in Chinese genotype 1 CHC patients receiving a 24-week course therapy with peginterferon alpha-2b/ribavirin. METHODS: A total of 133 biopsy-proven CHC patients were enrolled for analyses. Insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA-IR). Hepatic fibrosis was graded by the METAVIR scoring system. RESULTS: Mean HOMA-IR progressively elevated along with the severity of hepatic fibrosis (F1-F2 fibrosis: 2.55 +/- 0.16 vs. F3-F4 fibrosis: 3.61 +/- 0.20, P < 0.001). Compared with patients with sustained virological response (SVR), patients without SVR had significantly higher percentages of F3-F4 fibrosis (62.2% vs. 21.6%, P < 0.001) and baseline high viral load (>or=600,000 IU/mL; 64.4% vs. 35.6%, P = 0.038). In addition, patients without SVR had significantly higher plasma levels of insulin (15.03 +/- 0.89 vs. 10.19 +/- 0.55 microU/mL, P < 0.001) and HOMA-IR values (3.76 +/- 0.23 vs. 2.50 +/- 0.15, P < 0.001). Multivariate analyses showed that F1-F2 fibrosis (odds ratio: 4.49, P = 0.001), HOMA-IR < 2 (odds ratio: 7.15, P = 0.005) and pre-treatment hepatitis C virus RNA < 600,000 IU/mL (odds ratio: 3.26, P = 0.012) were the independent factors associated with SVR. CONCLUSIONS: Insulin resistance is a major determinant of SVR in genotype 1 CHC patients receiving peginterferon alpha-2b/ribavirin. Strategies to modify insulin resistance may be effective in enhancing SVR before or during anti-viral therapy.

Chronic treatment with carvedilol improves Ca(2+)-dependent ATP consumption in triton X-skinned fiber preparations of human myocardium.

Evidence is given that beta-blocker treatment differentially influences gene expression and up-regulation of beta(1)-adrenoceptors in human myocardium. Here, we investigate whether long-term treatment with carvedilol or metoprolol may functionally alter myofibrillar function in end-stage human heart failure. Investigations were performed in Triton X (1%, 4 degrees C, 20 h)-skinned fiber preparations of explanted hearts from patients undergoing heart transplantation due to idiopathic dilative cardiomyopathy. Five patients were not on beta-adrenoceptor blocker treatment (DCM_NBB), and 5 patients received either carvedilol (DCM_CAR) or metoprolol (DCM_MET). Nonfailing (NF) donor hearts (n = 5), which could not be transplanted due to technical reasons, were investigated for comparison. Ca(2+)-dependent tension (DT) development and actomyosin-ATPase activity (MYO) were measured and tension-dependent ATP consumption was calculated by the ratio of DT and MYO ("tension cost"). In addition, we measured the phosphorylation of troponin I (TNI) by back phosphorylation. Maximal DT and TNI phosphorylation were reduced, with myofibrillar Ca(2+) sensitivity of DT and MYO as well as tension cost being increased in DCM_NBB compared with NF. Metoprolol treatment restored TNI phosphorylation, decreased Ca(2+) sensitivity of tension development and of myosin-ATPase activity, but did not alter the tension-dependent ATP consumption. Carvedilol treatment improved maximal DT and significantly decreased tension-dependent ATP consumption without altering myofibrillar Ca(2+) sensitivity. TNI dephosphorylation was increased in patients treated with carvedilol. In conclusion, chronic beta-adrenoceptor blockade functionally alters myofibrillar function. The more economic cross-bridge cycling in patients under carvedilol treatment may provide an explanation for the efficacy of carvedilol in the treatment of chronic heart failure patients.