Periodontal disease increases the severity of chronic obstructive pulmonary disease: a Mendelian randomization study.

BACKGROUND: Recent research suggests that periodontitis can increase the risk of chronic obstructive pulmonary disease (COPD). In this study, we performed two-sample Mendelian randomization (MR) and investigated the causal effect of periodontitis (PD) on the genetic prediction of COPD. The study aimed to estimate how exposures affected outcomes. METHODS: Published data from the Gene-Lifestyle Interaction in the Dental Endpoints (GLIDE) Consortium's genome-wide association studies (GWAS) for periodontitis (17,353 cases and 28,210 controls) and COPD (16,488 cases and 169,688 controls) from European ancestry were utilized. This study employed a two-sample MR analysis approach and applied several complementary methods, including weighted median, inverse variance weighted (IVW), and MR-Egger regression. Multivariable Mendelian randomization (MVMR) analysis was further conducted to mitigate the influence of smoking on COPD. RESULTS: We chose five single-nucleotide polymorphisms (SNPs) as instrumental variables for periodontitis. A strong genetically predicted causal link between periodontitis and COPD, that is, periodontitis as an independent risk factor for COPD was detected. PD (OR = 1.102951, 95% CI: 1.005-1.211, p = 0.039) MR-Egger regression and weighted median analysis results were coincident with those of the IVW method. According to the sensitivity analysis, horizontal pleiotropy's effect on causal estimations seemed unlikely. However, reverse MR analysis revealed no significant genetic causal association between COPD and periodontitis. IVW (OR = 1.048 > 1, 95%CI: 0.973-1.128, p = 0.2082) MR Egger (OR = 0.826, 95%CI:0.658-1.037, p = 0.1104) and weighted median (OR = 1.043, 95%CI: 0.941-1.156, p = 0.4239). The results of multivariable Mendelian randomization (MVMR) analysis, after adjusting for the confounding effect of smoking, suggest a potential causal relationship between periodontitis and COPD (P = 0.035). CONCLUSION: In this study, periodontitis was found to be independent of COPD and a significant risk factor, providing new insights into periodontitis-mediated mechanisms underlying COPD development.

Dysbiosis of saliva microbiome in patients with oral lichen planus.

BACKGROUND: Oral microbiota is not only important for maintaining oral health but also plays a role in various oral diseases. However, studies regarding microbiome changes in oral lichen planus (OLP) are very limited. To the best of our knowledge, there has been only two studies investigating salivary microbiome changes in OLP. Therefore, the purpose of this study was to identify the characteristic microbial profile in the saliva of OLP patients, with or without erosive lesions, and compare that with recurrent aphthous ulcer (RAU), a common oral immunological disorder that also shows multiple erosive/ulcerative lesions. Whole saliva samples were collected from 20 patients with OLP (erosive E, n = 10 and non-erosive NE, n = 10), 10 patients with RAU (U) and 10 healthy controls (C). DNA was extracted from the saliva samples, and the 16S rDNA gene V4 hypervariable region was analyzed using Illumina sequencing. RESULTS: We obtained 4949 operational taxonomic units (OTUs) from the V4 region in all saliva samples. Community composition analysis showed a clear decreased relative abundance of genera Streptococcus and Sphingomonas in saliva from RAU patients when compared to the other three groups. Relative abundance of Lautropia and Gemella were higher in E group, whereas relative abundance of Haemophilus and Neisseria were higher in NE group when compared to C group. Abiotrophia and Oribacterium were higher in OLP (combining E and NE groups), while Eikenella and Aggregatibacter were lower when compared to C group. There was statistically significance in α-diversity between E and RAU groups(p < 0.05). Significant differences in ß-diversity were detected in bacteria between E and C; NE and C; as well as E and NE groups. The LDA effect size algorithm identified the g_Haemophilus might be the potential biomarker in NE group. CONCLUSIONS: We found that salivary microbiome in erosive OLP was significantly different from that found in RAU; and these changes may be related to the underlying disease process rather than presence of ulcerative/erosive lesions clinically. In addition, our findings in bacterial relative abundance in OLP were significantly different from the previously reported findings, which points to the need for further research in salivary microbiome of OLP.

A single-component yet multifunctional tongue-mimicking sensor array for upconversion fluorescence biosensing.

In this work, we prepared a type of multiplexing upconversion nanoparticle (UCNP). There are three fluorescence emission peaks when our UCNPs are excited with 980 and 808 nm lasers. These fluorescence peaks of UCNPs can be quenched ("turn off") to varying degrees via fluorescence resonance energy transfer (FRET) when the UCNPs are coated with a polydopamine (PDA) layer, which is a universal quencher self-polymerized from dopamine (DA). Here, we create a novel single-component nanoprobe that can be used for the pattern recognition of antioxidants in a "turn on" manner by integrating with the prevention of PDA formation with an antioxidant. Our sensing strategy is based on the recovery of the fluorescence intensity of three emission peaks to different degrees due to different antioxidants with differential inhibition of PDA formation. Then, these three fluorescence emission peaks of UCNPs are innovatively selected as the sensor array, which enables us to discriminate multiple antioxidants and their mixtures. Simultaneously, the sensor array shows excellent performance in the chiral discrimination of cysteine enantiomers. This is a novel, innovative sensor array that requires only a single component to achieve the upconversion fluorescence pattern and recognize chiral molecules, and it elucidates a more innovative concept towards widespread applications.

Lipid peroxidation is another potential mechanism besides pore-formation underlying hemolysis of tentacle extract from the jellyfish Cyanea capillata.

This study was performed to explore other potential mechanisms underlying hemolysis in addition to pore-formation of tentacle extract (TE) from the jellyfish Cyanea capillata. A dose-dependent increase of hemolysis was observed in rat erythrocyte suspensions and the hemolytic activity of TE was enhanced in the presence of Ca2+, which was attenuated by Ca2+ channel blockers (Diltiazem, Verapamil and Nifedipine). Direct intracellular Ca2+ increase was observed after TE treatment by confocal laser scanning microscopy, and the Ca2+ increase could be depressed by Diltiazem. The osmotic protectant polyethylenglycol (PEG) significantly blocked hemolysis with a molecular mass exceeding 4000 Da. These results support a pore-forming mechanism of TE in the erythrocyte membrane, which is consistent with previous studies by us and other groups. The concentration of malondialdehyde (MDA), an important marker of lipid peroxidation, increased dose-dependently in rat erythrocytes after TE treatment, while in vitro hemolysis of TE was inhibited by the antioxidants ascorbic acid-Vitamin C (Vc)-and reduced glutathione (GSH). Furthermore, in vivo hemolysis and electrolyte change after TE administration could be partly recovered by Vc. These results indicate that lipid peroxidation is another potential mechanism besides pore-formation underlying the hemolysis of TE, and both Ca2+ channel blockers and antioxidants could be useful candidates against the hemolytic activity of jellyfish venoms.

3-D culture of human umbilical vein endothelial cells with reversible thermosensitive hydroxybutyl chitosan hydrogel.

The aim of this study was to present a non-trypsin 3D cell culture method with a reversible thermosensitive HBCS hydrogel. In this study, hydroxybutyl chitosan (HBCS) was synthesized by grafting hydroxybutyl groups on chitosan molecule chains. The prepared HBCS was water-soluble, and the reversible phase transformation temperature was 26 °C. Scanning electron microscope images illuminated the 3-D network of hydrogel formed irregular porous structure which ranged from 50-250 µm. Cell viability assay indicated that HBCS solution could promote the proliferation of human umbilical vein endothelial cells (HUVECs), and the boost of proliferation was enhanced with the increase of HBCS concentration. HBCS had no harm to the nitric oxide (NO) synthesis functionality of HUVECs. HUVECs could grow and reproduce inside the hydrogel, and showed good vitality after 14-days culture. Meanwhile, cells cultured inside the hydrogel could be passaged successively through the reversible phase transformation process of HBCS. The results revealed that HBCS have the potential to be used for 3-D cell culture without the use of trypsin.

Biotribological study of large diameter ceramic-on-CFR-PEEK hip joint including fluid uptake, wear and frictional heating.

A novel material combination of a large diameter Biolox(®) Delta zirconia-toughened-alumina (ZTA) head and a pitch-based carbon fibre reinforced poly ether-ether-ketone (CFR-PEEK) MOTIS(®) cup has been studied. The acetabular cups were inclined at three angles and tested using Durham Hip Simulators. The different inclination angles used did not have a significant effect on the wear rates (ANOVA, p = 0.646). Averaged over all cups, the wear rates were calculated to be 0.551 ± 0.115 mm(3)/10(6) cycles and 0.493 ± 0.107 mm(3)/10(6) cycles taking into account two types of soak controls; loaded at room temperature and unloaded at 37 °C respectively. Averaged across all femoral heads, the wear rate was 0.243 ± 0.031 mm(3)/10(6) cycles. The temperature change of the lubricant caused by the frictional heat was measured in situ. Friction factors measured using the Durham Friction Simulator were lower for the worn CFR-PEEK cups compared with unworn. This correlated with the decreased surface roughness. Even though relatively high friction was observed in these hemispherical hard-on-soft bearings, the wear rate is encouragingly low.

Case Report: Malignant Transformation of Noma: Repair by Forearm Flap.

Noma is a progressive infectious disease manifested by a necrotic ulcer of the mouth and face. It usually occurs in poor, malnourished children, with about 30,000-140,000 cases each year and a low survival rate. The exact cause of noma remains unclear, but bacterial infection has been postulated to be a major cause of this disease. Antibiotics and improved nutrition could help inhibit the progression of noma, but most patients still require oral surgery because of the bacterial infection-induced tissue damage. In this study, we report an unusual case of a noma patient whose facial lesion developed a malignancy. The necrotic tissue and infectious area were surgically resected, and a forearm flap was used to repair the patient's facial defect. This case aimed at increasing people's awareness of tropical diseases such as noma.

[Influence of fixed orthodontic treatment on oral health-related quality of life in adolescent and adult: a comparative study].

PROPOSE: To compare the changes in oral health-related quality of life(OHRQoL) among adolescent patients and adult patients during orthodontic treatment. METHODS: The clinical data were collected from 81 patients (aged 15 to 25 years old) who underwent comprehensive orthodontic treatment. The participants were divided into 2 groups: adolescent patients (n=43) and adult patients (n=38) by age. OHRQoL was assessed using the Oral Health Impact Profile (OHIP-14). All subjects were examined and interviewed at baseline and the end of 3 stages during orthodontics treatment. Friedman 2-way analysis of variance (ANOVA) and Wilcoxon signed rank tests were used to compare the relative changes of OHRQoL among different time points with SPSS 20.0 software package. RESULTS: The scores of OHIP-14 and all domains except communication disorder and social disability domain in adolescent and adult patients showed significant changes as well as a decrease trend. Only adults showed significant changes in communication disorder.Both groups had no significant difference. CONCLUSIONS: The impact of comprehensive orthodontic treatment on patients' OHRQoL is quite different. Orthodontists should pay attention to the differences and guide the patients accordingly.

Evaluation of the bactericidal effect of Er,Cr:YSGG, and Nd:YAG lasers in experimentally infected root canals.

The aim of this study was to evaluate the bactericidal effect of the Er,Cr:YSGG laser and the Nd:YAG laser in experimentally infected root canals. Sixty single-rooted teeth with straight canals were selected. After preparation and sterilization, the specimens were inoculated with Enterococcus faecalis for 3 weeks. After irradiation by lasers, the number of bacteria in each root canal was examined. The Er,Cr:YSGG laser gave a reduction of 77% after irradiation at 1 W and 96% at 1.5 W, but there was no significant difference (p > 0.05). The Nd:YAG laser gave a reduction of 97% at 1 W and 98% at 1.5 W, and there was no significant difference (p > 0.05). Compared with the Er,Cr:YSGG laser, the Nd:YAG laser is more effective (p < 0.05). In conclusion, both lasers systems have a significant bactericidal effect in infected root canals, and the Nd:YAG laser is more effective than the Er,Cr:YSGG laser.

[Effect of icraiin on turnover of alveolar bone during orthodontic tooth movement in rats].

PURPOSE: To observe the effect of icariin on turnover of paradentium as well as the mechanism of effects on osteoclast during orthodontic tooth movement in rats. METHODS: Forty-right SD rats were used to establish animal models of OTM and divided into two groups randomly: the control group and the experimental group. Rats in the experimental group were given 20 mg/（kg.d） icariin by intragastric administration, while rats in the control group received solvent with the same volume. The rats were sacrificed in batch on the 7th, 14th, 21st and 28th day after orthodontic treatment. The amount of tooth movement was measured, and histomorphometric analysis based on slices from periodontium adjacent to the maxillary first molars was used to observe new bone formation, bone resorption and quantify osteoclasts. Statistical analysis was performed by using SPSS 16.0 software package. RESULTS: The movement distance of the first molar was significantly larger in the icariin group than that in the control group (P<0.05). In the icariin group, the number of osteoclasts was significantly higher than the control group at the 7th day and then demonstrated a steady decrease. CONCLUSIONS: Icariin could accelerate OTM in rats through promoting bone turnover of alveolar bone.

Prevalence of Enterococcus faecalis in saliva and filled root canals of teeth associated with apical periodontitis.

To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis. Patients with apical periodontitis who were referred for endodontic retreatment were examined. The type and quality of the restoration, symptoms, quality of obturation were recorded. During retreatment, an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E. faecalis. The 16S rRNA technique was used to identify E. faecalis. A total of 32 women and 22 men (mean age: 38 years; s.d.: 11 years) and 58 teeth were studied. The prevalence of E. faecalis was 19% in the saliva and 38% in the root canals. The odds that root canals harbored E. faecalis were increased if the saliva habored this bacterium (odds ratio=9.7; 95% confidence interval=1.8-51.6; P<0.05). Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation (P<0.05). E. faecalis is more common in root canals of teeth with apical periodontitis than in saliva. The prevalence of E. faecalis in root canals is associated with the presence of E. faecalis in saliva.

Receptor activator of nuclear factor kappa B ligand and osteoprotegerin expression in chronic apical periodontitis: possible association with inflammatory cells.

BACKGROUND: Receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL) and osteoprotegerin (OPG) have been recently shown to play important roles in bone resorption. The aim of this study was to investigate the possible association between the expression of bone resorption regulators (RANKL and OPG) and inflammatory cell infiltration in chronic apical periodontitis. METHODS: The samples of chronic periapical lesions (n = 40) and healthy periapical tissues (n = 10) were examined for immunohistochemical analysis of RANKL and OPG. Lesion samples were further analyzed for the inflammatory infiltration condition. The inflammatory cell infiltration was scored in relation to immunohistochemical reactivity for CD3, CD20 and CD68. RESULTS: The number of RANKL-positive cells and the ratio of RANKL/OPG in chronic apical periodontitis were significantly higher than those in healthy periapical tissues (P < 0.001). The number of RANKL-positive cells was higher in lesions with severe inflammatory infiltration than in those with light inflammatory infiltration (P < 0.05). Significantly increased RANKL expression was found with T lymphocytes (CD3(+)), macrophages (CD68(+)) and B lymphocytes (CD20(+)) infiltration (P < 0.05). No association was found between the ratio of RANKL/OPG and inflammatory cell infiltration. CONCLUSIONS: RANKL expression was increased with T, B lymphocytes and macrophages infiltration, respectively in chronic periapical lesions. RANKL appears to be closely related to periapical inflammatory infiltrates. The relative ratio of RANKL/OPG may be a key determinant of RANKL-mediated bone resorption.

Identification of dominant pathogens in periapical lesions associated with persistent apical periodontitis.

OBJECTIVE: to identify dominant pathogens in the periapical lesions associated with persistent apical periodontitis. METHODS: thirty-three root-filled teeth with persistent apical periodontitis referred for surgical treatment were selected. Microbial samples were collected from the periapical lesions during apical surgery. Microbial identification was performed with species-specific primers prepared according to the sequence analysis data using a 16S rRNA technique. RESULTS: among the 33 cases, in 5 cases none of the target species were detected, 6 cases showed the presence of only one species, and 22 cases showed more than two species. Porphyromonas endodontalis (45% of sample) was the most commonly detected dominant microbial species in the study sample, followed by Actinomyces viscosus (42%), Candida albicans (36%) and Porphyromonas gingivalis (27%). Fusobacterium, Actinomyces israelii and Enterococcus faecalis were also detected in 27%, 21% and 15% of the sample, respectively. The most frequently isolated species, P. endodontalis, was in most cases detected together with Actinomyces (14 cases) and P. gingivalis (6 cases). None of the lesions analysed in the present study contained Prevotella intermedia. There was no correlation in relation to the presence of sinus tracts and the bacterial species. CONCLUSION: a mixed population of pathogens was found in the endodontic lesions associated with persistent apical periodontitis. P. endodontalis, A. viscosus, C. albicans and P. gingivalis were the dominant species identified.

Pulp revascularization of immature teeth with apical periodontitis: a clinical study.

INTRODUCTION: The purpose of this study was to examine the effect of a pulpal revascularization procedure for immature necrotic teeth with apical periodontitis. METHODS: Twelve patients, each with an immature permanent tooth with chronic or acute apical periodontitis, were recruited. A triantibiotic mix (ciprofloxacin, metronidazole, and minocycline) was used to disinfect the pulp for 1 week. Then a blood clot was created in the canal, over which grey mineral trioxide aggregate was placed. Patients were recalled periodically. RESULTS: Six patients dropped from the study (as a result of pain or failure to induce bleeding after canal disinfection) and instead received a standard apexification procedure. Another 3 patients did not attend any recall appointments. The remaining teeth (n = 3) were found to exhibit complete root development, with a positive response to pulp testing. CONCLUSIONS: Revascularization could be effective for managing immature permanent teeth with apical periodontitis with appropriate case selection.

[Clinical evaluation of different angulation radiograph in diagnosing multiple canals of mandibular first premolars in vivo].

OBJECTIVE: To investigate the efficiency of different angle projection radiograph in diagnosing multiple canals of mandibular first premolars. METHODS: Eighty-eight mandibular first premolars that needed endodontic treatment in vivo were selected. The radiograph was taken at a horizontal angles of 0, 20-30 degrees from mesial or distal direction of the tooth preoperative. According to the different angle projection radiographic evaluation, radiographic diagnosis of multiple canals were suspected. After the root canal orifice were detected and located with K files, the root canals were prepared using crown-down technique and obturated using cold lateral condensation technique. The configurations and numbers of root canals were identified and recorded. The postoperative radiograph was taken. According to configurations and postoperative radiograph, the root canal configuration was classified into type I -V. RESULTS: In eighty-eight mandibular first premolars, 31 multiple canals teeth were suspected in preoperative radiographic diagnosis, 30 multiple canal teeth were detected under clinical evaluation. In case of 31 multiple canal teeth suspected by preoperative radiographic diagnosis, 3 teeth were not found multiple canals under clinical evaluation. While in case of 2 teeth of one canal suspected by preoperative radiographic diagnosis, multiple canal was detected under clinical evaluation. In 31 multiple canal teeth suspected by preoperative radiographic diagnosis, 13 teeth were detected at a horizontal angles of 0 degree and 25 teeth were detected at a horizontal angles of 20-30 degree, 7 teeth were suspected at different angle projection. Clinical detected rate of multiple canal in mandibular first premolar were 34.09% (30/88), 70.00% of which were type IV and V. CONCLUSION: Different angulation radiograph of preoperative will assist to increase clinical detection rate of multiple canals in mandibular first premolar.