Single missing molar with wide mesiodistal length restored using a single or double implant-supported crown: A self-controlled case report and 3D finite element analysis.

PURPOSE: Based on a self-controlled case, this study evaluated the finite element analysis (FEA) results of a single missing molar with wide mesiodistal length (MDL) restored by a single or double implant-supported crown. METHODS: A case of a missing bilateral mandibular first molar with wide MDL was restored using a single or double implant-supported crown. The implant survival and peri-implant bone were compared. FEA was conducted in coordination with the case using eight models with different MDLs (12, 13, 14, and 15 mm). Von Mises stress was calculated in the FEA to evaluate the biomechanical responses of the implants under increasing vertical and lateral loading, including the stress values of the implant, abutment, screw, crown, and cortical bone. RESULTS: The restorations on the left and right sides supported by double implants have been used for 6 and 12 years, respectively, and so far have shown excellent osseointegration radiographically.The von Mises stress calculated in the FEA showed that when the MDL was >14 mm, both the bone and prosthetic components bore more stress in the single implant-supported strategy. The strength was 188.62-201.37 MPa and 201.85-215.9 MPa when the MDL was 14 mm and 15 mm, respectively, which significantly exceeded the allowable yield stress (180 MPa). CONCLUSIONS: Compared with the single implant-supported crown, the double implant-supported crown reduced peri-implant bone stress and produced a more appropriate stress transfer model at the implant-bone interface when the MDL of the single missing molar was ≥14 mm.

Dietary, Lifestyle, and Children Health.

Childhood is a critical period for the development of a healthy lifestyle and the prevention of chronic diseases in adulthood [...].

Respiratory microbiota imbalance in children with Mycoplasma pneumoniae pneumonia.

Although previous studies have reported the dysregulation of respiratory tract microbiota in infectious diseases, insufficient data exist regarding respiratory microbiota imbalances in the lower respiratory tracts (LRTs) of children with Mycoplasma pneumoniae pneumonia (MPP). Here, we analysed the microbial community using 16S rRNA gene sequencing. Finally, bronchoalveolar lavage fluid (BALF) samples from 158 children with MPP and 29 with bacterial or viral pneumonia (control group) were collected. The diversity of the microbial community was significantly different between the two groups. A significantly increased abundance of Tenericutes and Mycoplasma was detected in the MPP group, exceeding 67% and 65% of the total bacterial population, respectively. Using Mycoplasma abundance as the diagnostic method, the sensitivity and specificity of the model was 97.5% and 96.6%, respectively. Compared to the mild MPP group, lower alpha diversity and significantly increased Mycoplasma abundance were found in the severe MPP group (P < 0.01). The abundance of Mycoplasma was positively correlated with complications and clinical indices in children with severe MPP compared with children with mild MPP. Our study describes the features of the LRT microbiota of children with MPP and uncovered its association with disease severity. This finding may offer insights into the pathogenesis of MPP in children.

Association of intestinal microbiota and its metabolite markers with excess weight in Chinese children and adolescents.

OBJECTIVE: The objective of this study was to identify the intestinal microbiota and faecal metabolic biomarkers associated with excess weight in Chinese children and adolescents. METHODS: This cross-sectional study included 163 children aged 6-14 years (including 72 with normal-weight and 91 with overweight/obesity from three Chinese boarding schools). We used 16S rRNA high-throughput sequencing to analyse the diversity and composition of intestinal microbiota. Of these participants, we selected 10 children with normal-weight and 10 with obesity (matched 1:1 for school, sex and age) and measured faecal metabolites using ultra-performance liquid chromatography coupled with tandem mass spectrometry. RESULTS: Alpha diversity was significantly elevated in children with normal-weight compared to overweight/obese. Principle coordinate analysis and permutational multivariate analysis of variance revealed a significant difference in intestinal microbial community structure between the normal-weight and overweight/obese groups. The two groups differed significantly in the relative abundances of Megamonas, Bifidobacterium and Alistipes. In faecal metabolomics analysis, we identified 14 differential metabolites and 2 main differential metabolic pathways associated with obesity. CONCLUSION: This study identified intestinal microbiota and metabolic markers associated with excess weight in Chinese children.

Near-infrared light-responsive multifunctional hydrogel releasing peptide-functionalized gold nanorods sequentially for diabetic wound healing.

Treatment for chronic diabetic wounds remains a clinical challenge. Wound healing process occurs in three phases: inflammation, proliferation and remodeling. Several factors including bacterial infection, decreased local angiogenesis and diminished blood supply delay wound healing. There is an urgent need to develop wound dressings with multiple biological effects for different stages of diabetic wound healing. Here, we develop a multifunctional hydrogel with two-stage sequential release upon near-infrared (NIR) stimulation, antibacterial activity and pro-angiogenic efficacy. This hydrogel consists of covalently crosslinked bilayer structure, with the lower thermoresponsive poly(N-isopropylacrylamide)/gelatin methacrylate (NG) layer and the upper highly stretchable alginate/polyacrylamide (AP) layer embedding different peptide-functionalized gold nanorods (AuNRs) in each layer. Antimicrobial peptide-functionalized AuNRs released from NG layer exert antibacterial effects. After NIR irradiation, the photothermal transition efficacy of AuNRs synergistically enhances bactericidal efficacy. The contraction of thermoresponsive layer also promotes the release of embedded cargos during early stage. The pro-angiogenic peptide-functionalized AuNRs released from AP layer promote angiogenesis and collagen deposition by accelerating fibroblast and endothelial cell proliferation, migration and tube formation during the subsequent healing phases. Therefore, the multifunctional hydrogel with effective antibacterial activity, pro-angiogenic efficacy and sequential release behaviors is a potential biomaterial for diabetic chronic wound healing.

Screening of Peptides that Specifically Binds to M3-M4 Extracellular Domain of Sodium Pump α1 Subunit and Analysis of Their Bioactivity In Vitro and In Vivo.

Interaction between ouabain (OUA) and Na+/K+-pump remains in the current focus of hypertension research. This study aimed to find an oligopeptide that would antagonize the inhibitory effect of endogenous OUA on Na+/K+-pump and examine its activity at the cellular and organism levels. To this end, Phage Random 12 Peptide Library was employed to screen for specific polypeptide ligands that interact with M3-M4 extracellular domain of Na+/K+-pump α1 subunit known as OUA-binding site. Synthetic sequence ILEYTWLEAGGGS of extracellular domain M3-M4 of Na+/K+-pump α1 subunit was used as the target. The phage positive clones were screened and identified using the phage library and double sandwich ELISA. DNA was extracted and sequenced to synthesize 3 peptide ligands to Na+/K+-pump: P-A, P-B, and P-C. We also studied the effects of the short peptide with the highest potency for countering OUA on proliferation and apoptosis of EA.hy926 vascular endothelial cells and on systolic BP in spontaneously hypertensive rats (SHR). The effect of peptide P-A on proliferation (stimulation with physiological concentrations of OUA) and on apoptosis (stimulation with OUA in high concentrations) of EA.hy926 vascular endothelial cells was assessed by the MTT test and flow cytometry, respectively. In SHR rats, intravenous injection of P-A decreased systolic BP. Oligopeptide P-A competitively antagonized the inhibitory action of OUA on Na+/K+-pump, OUA-induced proliferation, and OUA-provoked apoptosis of cultured EA.hy926 cells. Our findings open vista for the emergence of novel hypertensive drugs.

Differences in body composition measurements assessed by air displacement plethysmography and dual-energy X-ray absorptiometry in young and middle-aged adults.

BACKGROUND & OBJECTIVES: Dual-energy X-ray absorptiometry (DXA) and air displacement plethysmography (ADP) are two widely used methods for body composition analysis (BCA). However, little is known about the discrepancies in the results of BCA obtained from the two methods in Chinese population. This study aimed to compare the measurement differences between DXA and ADP in young and middle-aged Chinese adults, and to explore the influential factors of this difference. METHODS: A total of 186 healthy volunteers (51.1% males) who aged 18-56 years old with body mass index (BMI) of 15.9-35.9 kg/m2 were enrolled. Fat mass (FM), fat mass percentage (FMP), and fat-free mass (FFM) were analyzed by both DXA and ADP within 1 h. RESULTS: In general, all the BCA measures of DXA and ADP were highly correlated (intraclass correlation coefficient ICC>0.80, P < 0.001), while differences were found between the two methods (all P < 0.001). At the population level, greater body fat estimates (FM: 1.8 ± 3.1 kg in males and 2.2 ± 2.4 kg in females; FMP: 2.4 ± 4.2% in males and 3.1 ± 3.5% in females), whereas lower FFM (-0.2 ± 3.1 kg in males and -0.9 ± 2.4 kg in females) were found for DXA than ADP. Moreover, the average difference in FM and FMP as referred to ADP changed from positive in underweight group to negative in obesity group, and vice versa for FFM. At the individual level, the proportion of relative errors for FM and FMP within ±15% was less than 10% in underweight subjects and over 75% in those with obesity. For FFM, all underweight subjects had a relative error within 15%, and the proportion was 90.5% for obese males and 85.0% for obese females. CONCLUSION: BCA results by DXA and ADP were highly correlated, but the differences between the two methods were strongly influenced by BMI status at both population and individual levels. Caution should be especially taken when interchanging body fat results measured by the two methods in underweight and obese subjects.

Consistency between 3 days' dietary records and 24-h urine in estimating salt intake in children and adolescents.

Purpose: This study aimed to evaluate the salt intake in boarding school students and the consistency between salt intake measurements based on 24-h urine and weighed dietary records over 3 consecutive days in this population. Methods: This was a school-based cross-sectional study. Overweight (including obesity) or hypertensive students aged 6-14 years and their normal counterparts were recruited for this study at three boarding schools in China. Three consecutive 24-h urine samples were collected from all participants. During the collection period of 24-h urine, the weighed diet records were collected in children who had all three meals at the school canteens on weekdays. Incomplete 24-h urine or dietary records were excluded from the analysis. Results: The median salt excretion was 6,218 [4,636, 8,290] mg by 24-h urine and 120 (82.2%) consumed excess salt among the participants. The median salt intake was 8,132 [6,348, 9,370] mg by dietary records and 112 (97.4%) participants consumed excess salt than recommended in participants who have all three meals in the school canteens. In children with complete dietary records and 24-h urine, the level of salt intake estimated by 24-h urine accounted for 79.6% of the dietary records. Conclusion: Our study showed that boarding school students consumed excessive salt from school canteens. Thus, policies or strategies targeting school canteens are urgently needed. Weighed dietary records are recommended if feasible.

Correction: Micro/nano-net guides M2-pattern macrophage cytoskeleton distribution via Src-ROCK signalling for enhanced angiogenesis.

Correction for 'Micro/nano-net guides M2-pattern macrophage cytoskeleton distribution via Src-ROCK signalling for enhanced angiogenesis' by Yang Yang et al., Biomater. Sci., 2021, DOI: 10.1039/d1bm00116g.

Different Cell and Tissue Behavior of Micro-/Nano-Tubes and Micro-/Nano-Nets Topographies on Selective Laser Melting Titanium to Enhance Osseointegration.

BACKGROUND AND PURPOSE: Micro-/nano-tubes (TNTs) and micro-/nano-nets (TNNs) are the common and sensible choice in the first step of combined modifications of titanium surface for further functionalization in the purpose of extended indications and therapeutic effect. It is important to recognize the respective biologic reactions of these two substrates for guiding a biologically based first-step selection. MATERIALS AND METHODS: TNTs were produced by anodic oxidation and TNNs were formed by alkali-heat treatment. The original selective laser melting (SLM) titanium surface was set as control. Surface characterization was evaluated by scanning electron microscopy, surface roughness, and water contact angle measurements. Osteoclastogenesis and osteogenesis were measured. MC3T3-E1 cells and RAW 264.7 cells were used for in vitro assay in terms of adhesion, proliferation, and differentiation. In vivo assessments were taken on Beagle dogs with micro-CT and histological analysis. RESULTS: TNN and TNT groups performed decreased roughness and increased hydrophilicity compared with SLM group. For biological detections, the highest ALP activity and osteogenesis-related genes expression were observed in TNT group followed by TNN group (P <0.05). Interestingly, when it comes to the osteoclastogenesis, TNNs displayed lowest TRAP activity and osteoclastogenesis-related genes expression and TNTs were lower than SLM but higher than TNNs (P <0.05). BV/TV around implants was highest in TNT group after 4 weeks (P <0.05). HE, ALP and TRAP staining showed that osteogenic and osteoclastic activity around TNTs were both higher than TNNs (P <0.05). CONCLUSION: TNNs and TNTs have dual advantages in promotion of osteogenesis and inhibition of osteoclastogenesis. Furthermore, TNNs showed better capability in inhibiting osteoclast activity while TNTs facilitated stronger osteogenesis. Our results implied that TNT substrates would take advantage in early application after implantation, while diseases with inappropriate osteoclast activity would prefer TNN substrates, which will guide a biologically based first-step selection on combined modification for different clinical purposes.

A meta-analysis indicating extra-short implants (≤ 6 mm) as an alternative to longer implants (≥ 8 mm) with bone augmentation.

Extra-short implants, of which clinical outcomes remain controversial, are becoming a potential option rather than long implants with bone augmentation in atrophic partially or totally edentulous jaws. The aim of this study was to compare the clinical outcomes and complications between extra-short implants (≤ 6 mm) and longer implants (≥ 8 mm), with and without bone augmentation procedures. Electronic (via PubMed, Web of Science, EMBASE, Cochrane Library) and manual searches were performed for articles published prior to November 2020. Only randomized controlled trials (RCTs) comparing extra-short implants and longer implants in the same study reporting survival rate with an observation period at least 1 year were selected. Data extraction and methodological quality (AMSTAR-2) was assessed by 2 authors independently. A quantitative meta-analysis was performed to compare the survival rate, marginal bone loss (MBL), biological and prosthesis complication rate. Risk of bias was assessed with the Cochrane risk of bias tool 2 and the quality of evidence was determined with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. 21 RCTs were included, among which two were prior registered and 14 adhered to the CONSORT statement. No significant difference was found in the survival rate between extra-short and longer implant at 1- and 3-years follow-up (RR: 1.002, CI 0.981 to 1.024, P = 0.856 at 1 year; RR: 0.996, CI 0.968 to 1.025, P = 0.772 at 3 years, moderate quality), while longer implants had significantly higher survival rate than extra-short implants (RR: 0.970, CI 0.944 to 0.997, P < 0.05) at 5 years. Interestingly, no significant difference was observed when bone augmentations were performed at 5 years (RR: 0.977, CI 0.945 to 1.010, P = 0.171 for reconstructed bone; RR: 0.955, CI 0.912 to 0.999, P < 0.05 for native bone). Both the MBL (from implant placement) (WMD: - 0.22, CI - 0.277 to - 0.164, P < 0.01, low quality) and biological complications rate (RR: 0.321, CI 0.243 to 0.422, P < 0.01, moderate quality) preferred extra-short implants. However, there was no significant difference in terms of MBL (from prosthesis restoration) (WMD: 0.016, CI - 0.036 to 0.068, P = 0.555, moderate quality) or prosthesis complications rate (RR: 1.308, CI 0.893 to 1.915, P = 0.168, moderate quality). The placement of extra-short implants could be an acceptable alternative to longer implants in atrophic posterior arch. Further high-quality RCTs with a long follow-up period are required to corroborate the present outcomes.Registration number The review protocol was registered with PROSPERO (CRD42020155342).

Micro/nano-net guides M2-pattern macrophage cytoskeleton distribution via Src-ROCK signalling for enhanced angiogenesis.

Implant surface topography has been proven to determine the fate of adhered macrophage polarization, which is closely related to the cytoskeletal arrangement during adhesion. Our purpose was to establish a topography that is favourable to M2 macrophage switching by regulating macrophage cytoskeleton distribution. Two micro/nano-net structures with different pore sizes were generated by alkali bathing at medium (SAM) or high (SAH) temperature based on the micro-level surface. Their surface characteristics, in vitro macrophage polarization and impact on endothelial cells were analysed. The in vivo macrophage response and osseointegration were also tested. The results showed that the micro/nano-net has high hydrophilicity and moderate roughness. In the SAH and SAM groups, macrophages exhibited an elongated cytoskeleton with tiny protrusions and had a high M2/M1 polarization ratio with enhanced angiogenic ability, and in vivo studies also showed faster angiogenesis and bone formation in these groups. SAH showed even better results than SAM. For cytoskeleton related pathway explanation, ROCK expression was upregulated and Src expression was downregulated at the early or late adhesion stage in both the SAH and SAM groups. These results indicated that the micro/nano-net structure guides elongated macrophage adhesion states via Src-ROCK signalling and switches macrophages towards the M2 phenotype, which provides a cytoskeleton-oriented topography design for an ideal immune response.

LL-37 inhibits LPS-induced inflammation and stimulates the osteogenic differentiation of BMSCs via P2X7 receptor and MAPK signaling pathway.

Oral diseases, such as periapical periodontitis and periodontitis, are characterized by inflammation-induced bone loss. LL-37, a human antimicrobial peptide (AMP), has multiple biological functions and the potential to promote osteogenesis. Therefore, this study aimed to investigate the regulatory effects of LL-37 within normal and inflammatory microenvironments. The roles of P2X7 receptor (P2X7R) and mitogen-activated protein kinase (MAPK) signaling pathway were also demonstrated. The results showed that LL-37 promoted bone marrow stromal cell (BMSC) proliferation, migration and osteogenic differentiation. LL-37 inhibited the expression of the inflammatory cytokines interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and receptor activator of nuclear factor kappa-B ligand (RANKL) at both protein and gene levels, and attenuated the lipopolysaccharide (LPS)-induced inhibition of osteogenesis. Immunofluorescence (IF) confirmed P2X7R expression in BMSCs. BBG, a P2X7R antagonist, significantly attenuated LL-37-promoted osteogenesis. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH2-terminal kinase (JNK) increased after LL-37 stimulation, which did not affect p38 phosphorylation. The effects of LL-37 on osteogenesis-related gene expression were markedly attenuated by selective inhibitors of ERK1/2 and JNK. Furthermore, a mouse model of LPS-stimulated calvarial osteolysis was established, and results showed that LL-37 markedly inhibited osteoclastic bone resorption. In conclusion, we speculate that LL-37 inhibits inflammation and promotes BMSC osteogenesis via P2X7R and MAPK signaling pathway.

[Blocking programmed death-ligand 1 attenuates maturation inhibition of dendritic cells by co-cultured breast cancer cells].

OBJECTIVE: To study if programmed death-ligand 1 (PL-L1) expression in breast cancer cell activates PD-L1/PD-1 pathway in dendritic cells to inhibit dendritic cell maturation. METHODS: Human monocytes were induced to differentiate into immature dendritic cells using GM-CSF and IL-4, and further to mature dendritic cells using TNF-α. PD-L1-expressing breast cancer cell line MDA-MB-231 was co-cultured in contact with the dendritic cells to observe the effects of the breast cancer cells on the maturation of the dendritic cells. A PD-L1 blocking antibody was applied to the co-culture, and the changes in the inhibitory effect of the MDA-MB-231 cells on dendritic cell maturation was observed. TNF-α-induced dendritic cells were treated with a recombinant human PD-L1 protein to study the effect of PD-L1/PD-1 pathway activation on the maturation of dendritic cells. The expression of PD-L1 in MDA-MB-231 cells and the dendritic cell maturation marker HLA-DR and CD83 were analyzed using flow cytometry. RESULTS: MDA-MB-231 cell line showed PD-L1 positivity on the cell membrane cells at a rate as high as (99.7∓0.15)%. In mature dendritic cells, the positivity rates for HLA-DR and CD83 were (88.8∓6.96)% and (18.36∓3.07)%, respectively, but in the co-culture system, the positivity rates of the dendritic cells were significantly decreased to (42.76∓10.52)% (P<0.01) and (9.93∓2.74)% (P<0.05), respectively, indicating that MDA-MB-231 cells inhibited the maturation of dendritic cells. Following treatment with a PD-L1 antibody isotype control, the percentages of HLA-DR- and CD83-positive cells in the co-culture were (45.17∓10.19)% and (10.15∓2.54)%, which were significantly increased to (63.46∓1.72)% and (16.46∓2.58)% after treatment with PD-L1 antibody, respectively (both P<0.05). Compared with the mature dendritic cell controls, the cells treated with the recombinant human PD-L1 protein exhibited significantly lowered percentages of HLA-DR-positive [from (84.23∓4.18)% to (2.56∓2.39)%, P<0.05] and CD83-positive cells [(87.26∓1.54)% to (60.67∓1.63)%, P<0.05]. CONCLUSION: The effect of PD-L1 antibody therapy on triple negative breast cancer can be partially mediated by blocking PD-L1 expression on breast cancer cell membrane, which attenuates the inhibition of dendritic cell maturation in the cancer microenvironment.

[Phosphorylation of ezrin Tyr477 is critical in invasion of breast cancer cells stimulated by precursor of nerve growth factor].

OBJECTIVE: To investigate the effect of precursor of nerve growth factor (proNGF) in promoting invasion of breast cancer cells and its relation with ezrin expression and phosphorylation of ezrin Thr567 and Tyr477. METHODS: Human breast cancer cell lines MDA-MB-231 and MCF-7 were stimulated by gradient concentrations of proNGF (0, 2.5, 5 and 10 ng/mL) for 16 h, and the invasion of the cells was assessed with Transwell assay. The expression of ezrin and the phosphorylation of ezrin Thr567 and ezrin Tyr477 in the treated cells were examined by Western blotting. MDA-MB-231 cells were transfected with pEnter-His-ezrinY477F (a dominant negative mutant) to study the role of phosphrylation of ezrin Tyr477 in the invasion of breast cancer cell stimulated by proNGF. RESULTS: proNGF significantly promoted MDA-MB-231 and MCF-7 cell invasion in a concentration-dependent manner (P<0.05), and concentration- and time-dependently increased the phosphorylation of ezrin Tyr477 (P<0.05) without affecting the expression of ezrin or the phosphorylation of ezrin Thr567. The specific inhibitor of src, SKI-606, significantly inhibited the phosphorylation of ezrin Tyr477 induced by proNGF. Transfection with pEnter-His- ezrinY477F inhibited proNGF-induced invasion and phosphorylation of ezrin Tyr477 in MDA-MB-231 cells (P<0.05). CONCLUSION: Phosphorylation of ezrin Tyr477 plays a critical role in the invasion of breast cancer cells stimulated by proNGF via proNGF/src/ezrin Tyr477 pathway.

[Nanog promotes the invasion of breast cancer cells by increasing PKCε expression].

OBJECTIVE: To study the relationship between Nanog-promoted metastasis of breast cancer and ezrin(T567) phosphorylation, and explore the possible mechanism by which Nanog regulates ezrin(T567) phosphorylation. METHODS: A siRNA construct targeting Nanog was transfected in breast cancer cells to knock down Nanog expression, and the changes in the cell invasion was detected using Transwell assay. The expression levels of Nanog and PKC and the phosphorylation level of ezrin(T567) were detected using Western blotting and immunofluorescent staining; the protein interaction between PKCε and ezrin was assayed by co-immunoprecipitation and Western blotting. RESULTS: Nanog knockdown significantly decreased the expression of PKCε protein, phosphorylation level of ezrin(T567) and the invasion ability of breast cancer cells. PKCε knockdown obviously decreased the phosphorylation level of ezrin(T567) in the cells, and PKCε and ezrin were co-immunoprecipitated. CONCLUDIONS: Nanogcan can upregulate the expression of PKCε to promote the phosphorylation of ezrin(T567), which can be a new mechanism by which Nanog promotes tumor metastasis.