Tantalum-incorporated hydroxyapatite coating on titanium implants: its mechanical and in vitro osteogenic properties.

OBJECTIVE: The fabrication of bioactive coatings on metallic implants to enhance osseointegration has become a topic of general interest in orthopedics and dentistry. Hydroxyapatite (HA) coating has been shown to induce bone formation and promote bone-implant integration. Unfortunately, poor mechanical performance has hindered this from becoming a favorable coating material. The majority of present studies have focused in incorporating different elements into HA coatings to improve mechanical properties. In recent years, tantalum (Ta) has received increasing attention due to its excellent biocompatibility and corrosion resistance. The aim of on the present study was to investigate the fabrication and biological performance of Ta-incorporated HA coatings. METHODS: Ta-incorporated HA coatings were fabricated using the plasma spray technique on a titanium substrate, and the surface characteristics and mechanical properties were examined. In addition, the effects of Ta-incorporated HA coatings on the biological behavior of mesenchymal stem cells (BMSCs) were investigated. RESULTS: Ta-incorporated HA coatings with microporous structure had higher roughness and wettability. In addition, the bonding strength of Ta/HA coatings with the substrate was substantially superior to HA coatings. Furthermore, Ta-incorporated HA coatings not only facilitated initial cell adhesion and faster proliferation, but also promoted the osteogenic differentiation of BMSCs. CONCLUSION: These results indicate that the incorporation of Ta could improve mechanical performance and increase the osteogenic activity of HA coatings. The Ta-incorporated HA coating fabricated by plasma spraying is expected to be a promising bio-coating material for metallic implants.

Pathological changes in the maxillary sinus mucosae of patients with recurrent odontogenic maxillary sinusitis.

OBJECTIVE: To study the structural and functional changes of maxillary sinus mucosae of patients with odontogenic maxillary sinusitis, and to improve the therapeutic effects. METHODS: Ten mucosal biopsy samples collected during the surgeries of patients with recurrent odontogenic maxillary sinusitis were selected as Group A. Another ten mucosal biopsy sample were collected during retention cyst-removing surgeries and referred to as Group B. The mucosae were put in 10% neutral formalin solution for 1 day and prepared into 5-7 µm thick paraffin sections which were subjected to hematoxylin-eosin staining. The reactions included: (1) Reaction with T-lymphocyte (CD-3); (2) reaction with T-helper cell (CD-4); (3) reaction with T-suppressing cell (CD-8); (4) reaction with B-lymphocyte (CD-20). Polymeric horseradish peroxidase visualized detection system was used. The contents of CD3, CD4, CD8 and CD20 in the stained cells of the maxillary sinus mucosal layer were calculated. The responses of receptors to muramidase were classified as mild, moderate and strong. All data were analyzed by Statistica 6.0 package for Windows based on Mann-Whitney non-parametric standards. RESULTS: The epithelial tissues in the maxillary sinus mucosa of Group B were covered with multiple rows of cilia. The epithelial cells of Group A suffered from degeneration, shrinkage and desquamation. Different cells were distributed in the autologous mucosal layer, of which macrophages, fibroblasts, lymphocytes and neutrophils were dominant. The average contents of macrophages and lymphocytes accounted for 42.8%. Lymphocyte subset analysis showed that the number of CD3 cells exceeded that of CD20 ones and there were more CD4+ cells than CD8+ ones. T-helper and T-suppressing cells were distributed remarkably differently. CD8+ cells were mainly located inside and under the epithelium, while CD4+ cells were scattered in the autologous matrix. CONCLUSION: For patients with recurrent odontogenic maxillary sinusitis, the maxillary sinus mucosa mainly suffered from regeneration of epithelial tissues and inhibition of cell proliferation, which were accompanied by damages to the protective and shielding effects of the mucociliary transport system. Macrophages and lymphocytes dominated in the infiltration of autologous mucosal layer, and the coexisting copious fibroblasts indicated the onset of inflammation.

Effects of rhBMP-2 on Bone Formation Capacity of Rat Dental Stem/Progenitor Cells from Dental Follicle and Alveolar Bone Marrow.

Dental stem/progenitor cells are a promising cell sources for alveolar bone (AB) regeneration because of their same embryonic origin and superior osteogenic potential. However, their molecular processes during osteogenic differentiation remain unclear. The objective of this study was to identify the responsiveness of dental follicle cells (DFCs) and AB marrow-derived mesenchymal stem cells (ABM-MSCs) to recombinant human bone morphogenetic protein-2 (rhBMP-2). These cells expressed vimentin and MSC markers and did not express cytokeratin and hematopoietic stem cell markers and showed multilineage differentiation potential under specific culture conditions. DFCs exhibited higher proliferation and colony-forming unit-fibroblast efficiency than ABM-MSCs; rhBMP-2 induced DFCs to differentiate toward a cementoblast/osteoblast phenotype and ABM-MSCs to differentiate only toward a osteoblast phenotype; and rhBMP-2-induced DFCs exhibited higher osteogenic differentiation potential than ABM-MSCs. These cells adhered, grew, and produced extracellular matrix on nanohydroxyapatite/collagen/poly(l-lactide) (nHAC/PLA). During a 14-day culture on nHAC/PLA, the extracellular alkaline phosphatase (ALP) activity of DFCs decreased gradually and that of ABM-MSCs increased gradually; rhBMP-2 enhanced their extracellular ALP activity, intracellular osteocalcin (OCN), and osteopontin (OPN) protein expression; and DFCs exhibited higher extracellular ALP activity and intracellular OCN protein expression than ABM-MSCs. When implanted subcutaneously in severe combined immunodeficient mice for 3 months, DFCs+nHAC/PLA+rhBMP-2 obtained higher percentage of bone formation area, OCN, and cementum attachment protein expression and lower OPN expression than ABM-MSCs+nHAC/PLA+rhBMP-2. These results showed that DFCs possessed superior proliferation and osteogenic differentiation potential in vitro, and formed higher quantity and quality bones in vivo. It suggested that DFCs might exhibit a more sensitive responsiveness to rhBMP-2, so that DFCs enter a relatively mature stage of osteogenic differentiation earlier than ABM-MSCs after rhBMP-2 induction. The findings imply that these dental stem/progenitor cells are alternative sources for AB engineering in regenerative medicine, and developing dental tissue may provide better source for stem/progenitor cells.

Combined Use of Recombinant Human BMP-7 and Osteogenic Media May Have No Ideal Synergistic Effect on Leporine Bone Regeneration of Human Umbilical Cord Mesenchymal Stem Cells Seeded on Nanohydroxyapatite/Collagen/Poly (l-Lactide).

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising alternative source of mesenchymal stem cells (MSCs) that are enormously attractive for clinical use. This study was designed to investigate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) and/or osteogenic media (OMD) on bone regeneration of hUC-MSCs seeded on nanohydroxyapatite/collagen/poly(l-lactide) (nHAC/PLA) in a rabbit model. The characteristics of stem cells were analyzed by plastic adherence, cell phenotype, and multilineage differentiation potential. Cell proliferation was examined using cell counting kit-8 assay. Osteogenic differentiation was evaluated by quantitative Ca2+ concentration, PO43- concentration, alkaline phosphatase (ALP) activity, osteocalcin (OCN) secretion, and mineralized matrix formation. Bone regeneration was investigated in jaw bone defect repair in rabbit by microcomputed tomography, fluorescent labeling, and hematoxylin and eosin staining. Except for initial stress response, OMD and OMD + rhBMP-7 inhibited the proliferation of hUC-MSCs seeded on nHAC/PLA; rhBMP-7 inhibited cell proliferation in the nonlogarithmic phase and attenuated the inhibitory effect of OMD on cell proliferation. The inhibitory effects of OMD, rhBMP-7, and OMD + rhBMP-7 on cell proliferation were ranked as OMD > OMD + rhBMP-7 > rhBMP-7. OMD, rhBMP-7, and OMD + rhBMP-7 promoted Ca2+ concentration, PO43- concentration, ALP activity, OCN secretion, and mineralized matrix formation of hUC-MSCs seeded on nHAC/PLA. The promoting effects of OMD, rhBMP-7, and OMD+rhBMP-7 on Ca2+ concentration, PO43- concentration, ALP activity, OCN secretion, and mineralized matrix formation were ranked as rhBMP-7 > OMD > OMD + rhBMP-7, OMD > OMD + rhBMP-7 > rhBMP-7, OMD > rhBMP-7 > OMD + rhBMP-7, rhBMP-7 > OMD + rhBMP-7 > OMD, and OMD > rhBMP-7 > OMD + rhBMP-7, respectively. In rabbit jaw bone defect repair, OMD, rhBMP-7, and OMD + rhBMP-7 enhanced bone regeneration of hUC-MSCs seeded on nHAC/PLA, but the largest bone mineral apposition rate and bone formation were presented in cultures with rhBMP-7. These findings suggested that the combined use of rhBMP-7 and OMD may have no ideal synergistic effect on bone regeneration of hUC-MSCs seeded on nHAC/PLA in rabbit jaw bone defect.

Microsurgical and Endovascular Treatment Outcomes in Pericallosal Artery Aneurysms: A Single Center Retrospective Analysis.

AIM: To summarize the clinical outcomes, follow-up results and to discuss the optimal therapeutic strategy for pericallosal artery aneurysms (PAAs). MATERIAL AND METHODS: From January 2013 to May 2017, the charts of 49 patients with PAAs, representing 2.43% of 2,018 consecutive patients with intracranial aneurysms (IAs) were reviewed. The clinical and radiological data of these patients were retrospectively analyzed. RESULTS: There were no technical failures in the clipping group, but one patient in the coiling group presented rebleeding during the operation, resulting in a poor prognosis. Although the difference was not significant, the coiling group had a better complete recovery rate than the clipping group [overall: coiling, n=20 (87.0%) vs clipping, n=11 (68.8%), p=0.33; unruptured PAAs: coiling, n=12 (92.3%) vs clipping, n=5 (83.3%); ruptured PAAs: coiling, n=8 (80%) vs clipping, n=6 (60%), p=0.63]. One patient in the coiling group exhibited recurrence. No patients experienced rebleeding during the follow-up period in either group. CONCLUSION: In our study, both endovascular coiling and microsurgery were technically feasible and achieved favorable clinical outcomes in patients with PAAs. Longer radiological follow-up is necessary. Patients should be evaluated by a multidisciplinary team prior to determining the optimal treatment modality.

Morphological Characteristics of Pericallosal Artery Aneurysms and Their High Propensity for Rupture.

BACKGROUND: Compared with intracranial aneurysms (IAs) at other locations, pericallosal artery aneurysms (PAAs) have demonstrated an extremely high risk of rupture. However, owing to their rarity, our understanding of their morphological characteristics has been limited, and whether the morphological characteristics of PAAs contribute to this high rupture risk has remained unexplored. In the present study, we aimed to provide a detailed description of the morphological characteristics of PAAs and investigate the association between its morphology and rupture risk compared with anterior circulation IAs at other locations. METHODS: A total of 40 patients with 45 PAAs and 348 patients with 392 anterior circulation IAs at other locations were recruited. The clinical and radiological data for these patients were retrospectively reviewed. The differences in the morphological parameters, including the aneurysm diameter, neck width, height, width, parent artery diameter, inflow angle, aspect ratio (AR), size ratio (SR), and aneurysm diameter/width ratio, between PAAs and other IA groups were compared. RESULTS: Of the 45 PAAs, 22 (48.9%) had ruptured. The proportion of ruptured aneurysms was greater for PAAs than for anterior circulation IAs at other locations. For both ruptured and unruptured anterior circulation IAs, PAAs had the highest AR and SR among all IA groups and had the largest inflow angle. CONCLUSION: The morphological characteristics of PAAs are unique. Compared with other anterior circulation IAs, PAAs have significantly increased ARs, SRs, and inflow angles, which, ultimately, promote their high propensity toward rupture.

Treatment of Saos-2 osteosarcoma cells with diallyl trisulfide is associated with an increase in calreticulin expression.

Diallyl trisulfide (DATS) is a natural organic sulfur compound that may be isolated from garlic and has strong anticancer activity. DATS has been demonstrated to upregulate the expression of calreticulin (CRT) in various types of human cancers, which is associated with the prognosis of cancer and its response to therapy. However, whether DATS has the same effect on human osteosarcoma cells is not known. Therefore, in the present study, Saos-2 human osteosarcoma cells were cultured with different concentrations of DATS (0, 25, 50 and 100 µmol/l) for 24 h, or with 50 µmol/l DATS for different time periods (0, 12, 24 and 36 h). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blotting and immunofluorescent staining were used to detect CRT mRNA and protein in the Saos-2 cells. Exposure to DATS changed the morphology and inhibited the growth of the Saos-2 cells, and its effects appeared to be concentration- and exposure time-dependent. The optimum concentration and exposure time of DATS were 50 µmol/l and 24 h, respectively. The levels of CRT mRNA and protein in the Saos-2 cells were significantly upregulated following exposure to DATS. The upregulation of CRT expression by DATS may be a mechanism underlying the ability of DATS to inhibit the growth of human osteosarcoma Saos-2 cells.

[Clinical research of heart rate turbulence on predictive value in patients with acute myocardial infarction].

OBJECTIVE: To assess the predictive value of heart rate turbulence (HRT) in patients with acute myocardial infarction. METHODS: One hundred and twenty-five patients with acute myocardial infarction were enrolled in this study. During the period from 6 to 21 days after onset of acute myocardial infarction, they were undergone 24-hour Holter recordings to collect the mean RR interval and heart rate variability (HRV) SDNN. The Holter files were processed with software of "HRT! View V0.60-1" to obtain the value of Turbulence Onset (TO) and Turbulence Slope (TS) and the value of "heart rate variability (HRV) SDNN". LVEF and EDD were measured by Ultrasonic Cardiography. Endpoint of follow-up was cardiac death. According to the results, patients were divided into two groups (the "survivors" and the "nonsurvivors"). The predictive value for high-risk patients with acute myocardial infarction was assessed by variables between the two groups. RESULTS: In the period of follow-up (mean 225.4 +/- 99.8 days), 14 patients died and 111 patients survived. In the univariate Cox regression analysis, "TS" was a strong univariate predictor of mortality (hazard ratio 11.46, P < 0.01); "TO" was a relatively weak predictor and the hazard ratio was 2.76 (P > 0.05). Combination of abnormal TO and abnormal TS was the strongest mortality predictor (hazard ratio 26.70, P < 0.01); in the multivariate Cox regression analysis, TS < or = 2.5 ms/RR and EDD > or = 5.6 cm were the independent predictors of mortality with hazard ratios 9.49 (P < 0.01) and 3.64 (P < 0.05), respectively. CONCLUSIONS: The absence of the heart rate turbulence after ventricular premature beats is a very potent post-infarction risk predictor which is independent of and stronger than other known risk predictors.

[Relationship between HLA-A, B alleles and red blood cell parameters of patients with --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population of Wuzhou city].

This study was purposed to investigate the relationship between HLA-A, B allele polymorphisms and red blood cell parameters of patients with --(SEA/αα) subtype of α(0)-thalassemia in Han ethnic population of Wuzhou city. The HLA genetic polymorphisms were determined by polymerase chain reaction-sequence-based typing (PCR-SBT) in 57 patients with --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population in Wuzhou city, Guangxi province, China. Mean corpuscular volume (MCV), hemoglobin (Hb), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were detected by automatic blood analyzer system. HbA2 were detected by electrophoretic method. The statistical analysis was performed by ordinal polytomous logistic regression. The results showed that Hb and HbA2 levels were significantly lower in patients positive for HLA-A*33:03, B*15:01 or B*55:02, and were significantly higher in patients positive for B*15:02 (P < 0.05). It is concluded that several HLA alleles may be associated with Hb level of --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population in Wuzhou city. This result has the value for understanding phenotype-genotype relationships in thalassemia.