Optimal tooth sectioning using a surgical handpiece and elevator: a finite element study of horizontally deeply impacted mandibular third molars.

OBJECTIVES: To conduct a finite element analysis of the impact of different variables on tooth sectioning efficiency and trauma to surrounding tissues when utilizing high-speed surgical handpieces and elevators. METHODS: CBCT data from the horizontally impacted third mandibular molar (M3M) of a patient were utilized to establish digital models of the M3M, adjacent M2M, and surrounding bone. To simulate tooth sectioning, a 3D finite element model was established with the following variables: remaining tooth tissue thickness (1-5 mm), tooth section fissure width (1-3 mm), elevator depth in fissure (2-6 mm), elevator position (buccal, lingual, central), elevator width (2-5 mm), and application of force (rotating, levering). Using this model, the distribution of stress on the M3M and the surrounding tissue was assessed while measuring tooth sectioning efficiency and trauma to the surrounding tissue. RESULTS: Factors associated with uniform stress at the site of sectioning included thin (≤ 3 mm) remaining tooth tissue, appropriate fissure width (~ 2 mm), a wide (≥ 4 mm) elevator, and central elevator positioning. Levering the elevator yielded greater stress on the M3M than rotating force. Greater sectioning efficiency was associated with increased stress placed on the distobuccal side of M2M. CONCLUSIONS: Tooth sectioning efficiency can be improved by adjusting the high-speed surgical handpiece and elevator. However, it is important to remain attentive to the trauma to which adjacent teeth are exposed during this process. CLINICAL SIGNIFICANCE: These results offer guidance for approaches to improving operator efficiency and reducing trauma to surrounding tissues during tooth sectioning.

MT1G induces lipid droplet accumulation through modulation of H3K14 trimethylation accelerating clear cell renal cell carcinoma progression.

BACKGROUND: Lipid droplet formation is a prominent histological feature in clear cell renal cell carcinoma (ccRCC), but the significance and mechanisms underlying lipid droplet accumulation remain unclear. METHODS: Expression and clinical significance of MT1G in ccRCC were analyzed by using TCGA data, GEO data and scRNASeq data. MT1G overexpression or knockdown ccRCC cell lines were constructed and in situ ccRCC model, lung metastasis assay, metabolomics and lipid droplets staining were performed to explore the role of MT1G on lipid droplet accumulation in ccRCC. RESULTS: Initially, we observed low MT1G expression in ccRCC tissues, whereas high MT1G expression correlated with advanced disease stage and poorer prognosis. Elevated MT1G expression promoted ccRCC growth and metastasis both in vitro and in vivo. Mechanistically, MT1G significantly suppressed acylcarnitine levels and downstream tricarboxylic acid (TCA) cycle activity, resulting in increased fatty acid and lipid accumulation without affecting cholesterol metabolism. Notably, MT1G inhibited H3K14 trimethylation (H3K14me3) modification. Under these conditions, MT1G-mediated H3K14me3 was recruited to the CPT1B promoter through direct interaction with specific promoter regions, leading to reduced CPT1B transcription and translation. CONCLUSIONS: Our study unveils a novel mechanism of lipid droplet accumulation in ccRCC, where MT1G inhibits CPT1B expression through modulation of H3K14 trimethylation, consequently enhancing lipid droplet accumulation and promoting ccRCC progression. Graphical abstract figure Schematic diagram illustrating MT1G/H3K14me3/CPT1B-mediated lipid droplet accumulation promoted ccRCC progression via FAO inhibition.

Effect of mineralized dentin matrix on the prognosis of bone defect and retained root after coronectomy.

OBJECTIVE: To investigate the impact of mineralized dentin matrix (MDM) on the prognosis on bone regeneration and migration of retained roots after coronectomy. MATERIALS AND METHODS: Patients were divided into three groups based on the type of bone graft after coronectomy: Group C (n = 20, collagen), Group T (n = 20, tricalcium phosphate (TCP) + collagen), and Group D (n = 20, MDM + collagen). CBCT scans, conducted immediately and 6 months after surgery, were analyzed using digital software. Primary outcomes, including changes in bone defect depth and retained root migration distance, were evaluated 6 months after surgery. RESULTS: After 6 months, both Groups D and T exhibited greater reduction of the bone defect and lesser retained root migration than Group C (p < 0.001). Group D had greater regenerated bone volume in the distal 2 mm (73 mm3 vs. 57 mm3, p = 0.011) and lesser root migration (2.18 mm vs. 2.96 mm, p < 0.001) than Group T. The proportion of completely bone embedded retained roots was also greater in Group D than in Group C (70.0% vs. 42.1%, p = 0.003). CONCLUSIONS: MDM is an appropriate graft material for improving bone defect healing and reducing retained root migration after coronectomy. CLINICAL RELEVANCE: MDM is an autogenous material prepared chairside, which can significantly improve bone healing and reduce the risk of retained root re-eruption. MDM holds promise as a routine bone substitute material after M3M coronectomy.

CCR9+CD4+ T cells are associated with disease activity in patients with rheumatoid arthritis.

An increase in CD4+ T cells in the synovium is closely linked to the pathogenesis of rheumatoid arthritis (RA). We aimed to identify the possible causes of the elevated CD4+ T cell levels and to explore the factors influencing disease activity in RA. Fifty-five RA patients, including 28 with active RA (ARA), 27 with inactive RA, and 22 healthy controls, were recruited for this study. The proportion of CCR9+CD4+ T cells and the expression of chemokine receptor 9 (CCR9) on CD4+ T cells were analyzed by flow cytometry. Enzyme-linked immunosorbent assay and chemiluminescent immunoassay were used to evaluate interleukin (IL)-17A and IL-6 levels, respectively. The proportion of CCR9+CD4+ T cells and the expression of CCR9 on CD4+ T cells increased significantly in peripheral blood (PB) and synovial fluid (SF) in ARA compared to those in inactive RA. Furthermore, SF contained more CCR9+CD4+ T cells, IL-6, and IL-17A than PB in RA patients. Moreover, CD4+ T cells in the PB of patients with RA, especially ARA, expressed more CCR9 and secreted more IL-6 and IL-17A after activation. Here, we also demonstrated that both the percentage of CCR9+ cells in CD4+ T cells and the expression of CCR9 on circulating CD4+ T cells were positively correlated with erythrocyte sedimentation rate, hypersensitive C-reactive protein, rheumatoid factor, and anti-cyclic citrullinated peptide antibody. CCR9+CD4+ T cells are elevated in PB and SF, and are associated with disease activity in patients with RA.

Training semantic long-term memory retrieval transfers to executive function and reading fluency.

The retrieval of information from long-term memory is a fundamental cognitive ability, crucial for most aspects of successful human functioning. Whether and how long-term memory retrieval (LTMR) can be improved with training has clear societal importance but also theoretical value for furthering our understanding of underlying mechanisms. Here, we provide electrophysiological evidence for the plasticity of semantic LTMR. Thirty-five university students were randomly assigned to adaptive semantic LTMR training (using a Posner task) or to a non-adaptive version of the training. Before and after training they were assessed on measures of semantic LTMR, working memory, central executive function (interference control, switching), reading fluency, and fluid intelligence. Adaptive LTMR training (relative to non-adaptive training) led to significant improvements in semantic LTMR. The intervention group (in contrast to the control group) also showed a significant reduction in the mean amplitude of the N400 ERP component and 700-1000 ms measured during a semantic LTMR task, suggesting that changes in retrieval occurred at an early/automatic point and retrieval processing in semantic processing. Moreover, transfer effects were observed for switching, working memory and reading fluency, but not for interference control or fluid intelligence. These results point to the plasticity of semantic LTMR, and suggest that improvement in this ability can transfer to other domains for which LTMR is key.

Analysis of the aerodynamic characteristics of the upper airway in obstructive sleep apnea patients.

Background/purpose: This study was designed to explore upper airway aerodynamic characteristics in individuals diagnosed with obstructive sleep apnea (OSA) and to evaluate correlations between these characteristics and other anatomical upper airway findings in these patients. Materials and methods: This was a retrospective study of 40 OSA patients (22 male, 18 female) who were stratified into groups with mild, moderate, and severe disease based upon overnight polysomnographic (PSG) recording results. Newtom5G cone-beam CT scans (CBCT) were conducted for all patients, and the resultant images were used to reconstruct three-dimensional images of the upper airways which were used to calculate aerodynamic characteristics. Differences in these characteristics between groups were evaluated with one-way ANOVAs, while relationships between anatomical and aerodynamic characteristics were assessed through Pearson correlation analyses. Results: The aerodynamic of the upper airway has typical characteristic in severe group. There was a significant negative correlation in severe group between resistance during inspiration (Rin) and volume (V) (r = -0.693, P = 0.013), minimum axial area (MMA) (r = -0.685, P = 0.014), and lateral dimension (LAT) (r = -0.724, P = 0.008), resistance during expiration (Rex) and LAT (r = -0.923, P < 0.001). Conclusion: This study showed that airway resistance during inspiration and expiration are most closely associated with upper airway collapse in OSA patients, with repetitive collapse occurring during both of these breathing processes. LAT may be an important anatomical factor associated with OSA pathogenesis and treatment.

The impacts of registration-and-fixation device positioning on the performance of implant placement assisted by dynamic computer-aided surgery: A randomized controlled trial.

OBJECTIVES: To assess the efficacy of dynamic computer-aided surgery (dCAS) in replacing a single missing posterior tooth, we compare outcomes when using registration-and-fixation devices positioned anterior or posterior to the surgical site. Registration is performed on either the anterior or opposite posterior teeth. METHODS: Forty individuals needing posterior single-tooth implant placement were randomly assigned to anterior or posterior registration. Nine parameters were analyzed to detect the deviations between planned and actual implant placement, using Mann-Whitney and t-tests for nonnormally and normally distributed data, respectively. RESULTS: The overall average angular deviation for this study was 2.08 ± 1.12°, with the respective average 3D platform and apex deviations of 0.77 ± 0.32 mm and 0.88 ± 0.32 mm. Angular deviation values for individuals in the anterior and posterior registration groups were 1.58°(IQR: 0.98°-2.38°) and 2.25°(IQR: 1.46°-3.43°), respectively (p = .165), with 3D platform deviations of 0.81 ± 0.29 mm and 0.74 ± 0.36 mm (p = .464), as well as 3D apex deviations of 0.89 ± 0.32 mm and 0.88 ± 0.33 mm (p = .986). No significant variations in absolute buccolingual (platform, p = .659; apex, p = .063), apicocoronal (platform, p = .671; apex, p = .649), or mesiodistal (platform, p = .134; apex, p = .355) deviations were observed at either analyzed levels. CONCLUSIONS: Both anterior and posterior registration approaches facilitate accurate dCAS-mediated implant placement for single missing posterior teeth. The device's placement (posterior-to or anterior-to the surgical site) did not affect the clinician's ability to achieve the planned implant location.

Alveolar ridge preservation of two-wall bone defects using mineralized dentin matrix: An experimental pre-clinical study.

OBJECTIVES: To study bone healing of two-wall bone defects after alveolar ridge preservation using mineralized dentin matrix. MATERIALS AND METHODS: After distal roots extraction of second and fourth premolars (P2, P4) on one lateral mandible in 12 beagles, two-wall bone defects (5 × 5 × 5 mm) were surgically created distally to the remaining mesial roots of P2 and P4. A total of 24 sites were randomly allocated to three groups (implant material- time of execution): mineralized dentin matrix (MDM)-3 m (MDM + collagen membrane; 3 months), MDM-6 m (MDM particles + collagen membrane; 6 months), and C-6 m (collagen membrane only; 6 months). Clinical, radiographic, digital, and histological examinations were performed 3 and 6 months after surgery. RESULTS: The bone healing in MDM groups were better compared to Control group (volume of bone regenerated in total: 25.12 mm3 vs. 13.30 mm3, p = .046; trabecular volume/total volume: 58.84% vs. 39.18%, p = .001; new bone formation rate: 44.13% vs. 31.88%, p = .047). Vertically, the radiological bone level of bone defect in MDM-6 m group was higher than that in C-6 m group (vertical height of bone defect: 1.55 mm vs. 2.74 mm, p = .018). Horizontally, no significant differences in buccolingual bone width were found between MDM and C groups at any time or at any level below the alveolar ridge. The percentages of remaining MDM were <1% in both MDM-3 m and MDM-6 m groups. CONCLUSIONS: MDM improved bone healing of two-wall bone defects and might be considered as a socket fill material used following tooth extraction.

Accuracy of computer-assisted dynamic navigation when performing coronectomy of the mandibular third molar: A pilot study.

OBJECTIVES: The study represents a preliminary evaluation of the accuracy of the dynamic navigation system (DNS) in coronectomy of the mandibular third molar (M3M). METHODS: The study included participants with an impacted M3M near the inferior alveolar canal. The coronectomy planes were designed before the surgery using cone-beam computed tomography (CBCT) imaging data and then loaded into the DNS program. Intraoperatively, the navigation system was used to guide the complete removal of the target crown. Postoperative CBCT imaging was used to assess any three-dimensional deviations of the actual postoperative from the planned preoperative section planes for each patient. RESULTS: A total of 12 patients (13 teeth) were included. The root mean square (RMS) deviation of the preoperatively designed plane from the actual postoperative surface was 0.69 ± 0.21 mm, with a maximum of 1.45 ± 0.83/-1.87 ± 0.63 mm deviation. The areas with distance deviations < 1 mm, 1-2 mm, and 2-3 mm were 71.97 ± 5.72 %, 22.96 ± 6.57 %, and 4.52 ± 2.28 %, respectively. Most patients showed extremely high convexity of the surface area located in the mesial region adjacent to the base of the extraction socket. There was no observable evidence of scratching of the buccolingual bone plate at the base of the extraction socket by the handpiece drill. CONCLUSIONS: These results provide preliminary support for the use of DNS-based techniques when extracting M3M using a buccal approach. This would improve the accuracy of coronectomy and reduce the potiential damage to the surrounding tissue. CLINICAL SIGNIFICANCE: DNS is effective for guiding coronectomy.

Accuracy of different registration areas using active and passive dynamic navigation systems in dental implant surgery: An in vitro study.

OBJECTIVES: To gauge the relative accuracy of the use of passive and active dynamic navigation systems when placing dental implants, and to determine how registration areas affect the performance of these systems. MATERIALS AND METHODS: Eighty implants were assigned to be placed into 40 total resin mandible models missing either the left or right first molars using either passive or active dynamic navigation system approaches. U-shaped tube registration devices were fixed in the edentulous site for 20 models each on the left or right side. Planned and actual implant positions were superimposed to assess procedural accuracy, and parameters including 3D entry deviation, angular deviation, and 3D apex deviation were evaluated with Mann-Whitney U tests and Wilcoxon signed-rank tests. RESULTS: Respective angular, entry, and apex deviation values of 1.563 ± 0.977°, 0.725 ± 0.268 mm, and 0.808 ± 0.284 mm were calculated for all included implants, with corresponding values of 1.388 ± 1.090°, 0.789 ± 0.285 mm, and 0.846 ± 0.301 mm in the active group and 1.739 ± 0.826°, 0.661 ± 0.236 mm, and 0.769 ± 0.264 mm in the passive group. Only angular deviation differed significantly among groups, and the registration area was not associated with any significant differences among groups. CONCLUSIONS: Passive and active dynamic navigation approaches can achieve comparable in vitro accuracy. Registration on one side of the missing single posterior tooth area in the mandible can complete single-tooth implantation on both sides of the posterior teeth, highlighting the promise of further clinical research focused on this topic.

Analysis of the accuracy of a dynamic navigation system when performing dental implant surgery with transcrestal sinus floor elevation: A pilot study.

Background/purpose: The success of transcrestal sinus floor elevation (TSFE) is primarily reliant upon the experience of the surgeon owing to the limited operative visibility. To evaluate the accuracy associated with the use of a dynamic navigation system when conducting posterior maxilla implant surgery with TSFE. Materials and methods: Twenty-eight implants were placed in 28 patients requiring implantation in the posterior maxilla via a TSFE approach. The drills were used to access the planned position (within 1 mm of the bottom of the maxillary sinus floor) under dynamic navigation system. TSFE was then accomplished using osteotomes and a piezoelectric device. Lastly, the implant was inserted under the dynamic navigation. Three effective deviations between planned and actual implant placement were then measured including angular deviation (AD, degrees), entry point horizontal deviation (EPHD, mm), and apical point horizontal deviation (APHD, mm). Results: The AD, EPHD, and APHD between the planned and actual implant placement were 3.656 ± 1.665°, 1.073 ± 0.686 mm, and 1.086 ± 0.667 mm, respectively. Premolar site AD values were less than those for molar sites (P = 0.004). No significant differences in these outcomes were observed in different surgeons. Obvious sinus perforation was not detected by immediate postoperative cone beam computed tomography imaging. Conclusion: The accuracy associated with using a dynamic navigation system when conducting posterior maxilla implant surgery via a TSFE approach using piezoelectric devices was comparable. This technique thus achieved appropriate interventional precision and safety while decreasing the morbidity associated with the TSFE approach.

The use of shear wave elastography to monitor changes in gingival elasticity associated with initial periodontal therapy in patients with advanced periodontitis: A prospective pilot study.

Background/purpose: Gingival tissue firmness cannot be objectively assessed or monitored in real-time in existing examinations. This study was designed to examine the potential utility of shear wave elastography (SWE) as a means of evaluating and monitoring gingival inflammation in an effort to assess the effects of initial periodontal therapy in patients with advanced periodontitis. Materials and methods: This pilot study included analyses of 66 sites in 6 advanced periodontitis patients. Patients underwent the SWE examination of the gingiva at the mid-labial and interdental papillae at baseline and at 2, 4, and 6 weeks following initial periodontal therapy. Measured periodontal parameters in these patients include Plaque index (PI), Gingival bleeding index (GBI), Probing depth (PD), and Clinical attachment loss (CAL). Results: Respective baseline SWE values at the mid-labial gingiva and interdental papilla 25.68 ± 6.82 kPa and 26.78 ± 6.20 kPa, with no significant differences between these two measures. A significant negative correlation between SWE and both PI (r = -0.350, P = 0.004) and GBI (r = -0.287, P = 0.020) was observed at baseline. Initial periodontal therapy contributed to significantly higher SWE values and tougher gingiva, particularly during the first two weeks. Postoperative changes in SWE were negatively correlated with SWE values at baseline (r = -0.710, P < 0.001). Conclusion: These results establish SWE as a sensitive noninvasive approach to quantitatively assessing changes in gingival elasticity in real-time.

Accuracy of automatic and manual dynamic navigation registration techniques for dental implant surgery in posterior sites missing a single tooth: A retrospective clinical analysis.

OBJECTIVES: To assess the relative accuracy of manual (U-shaped tube) and automatic (two-in-one) dynamic navigation registration techniques for implant surgery performed in posterior sites missing one tooth. MATERIALS AND METHODS: This study included 58 partially edentulous patients with 58 implants, including 31 and 27 in the manual and automatic groups. Deviations between the planned and actual implant placement were assessed. RESULTS: The angular deviation in the overall study cohort was 2.54 ± 1.21°, while the 3D deviations at the implant platform and apex were 0.90 ± 0.46 mm and 1.04 ± 0.47 mm, respectively. The respective angular deviations in the manual and automatic groups were 2.82 ± 1.17° and 2.21 ± 1.19° (p > .05), while platform deviations were 0.89 ± 0.48 mm and 0.91 ± 0.45 mm (p > .05), and apex deviations were 0.99 ± 0.48 mm and 1.11 ± 0.46 mm (p > .05). No significant differences in absolute buccolingual, mesiodistal, or apicocoronal deviations were detected between these groups at either level (p > .05) nor were did deviation distributions differ in the buccolingual, mesiodistal, or apicocoronal directions at the platform or apex levels (p > .05). CONCLUSIONS: Manual and automatic dynamic navigation registration techniques can achieve excellent accuracy when placing implants in posterior sites missing a single tooth. The two-in-one automatic registration technique can reduce the amount of time and intraoperative steps necessary to complete the registration process relative to the manual U-shaped tube registration technique. Further follow-up studies are necessary to expand on these results.

A registration-and-fixation approach with handpiece adjustment for dynamic navigation in dental implant surgery.

The deviations between the preoperative (planned) and postoperative (actual) positions of dental implants have always been of a major concern in dental implant surgery. Dynamic computer-aided implant surgery (dCAIS) systems have been used to achieve optimal implant positioning. The method of registration is indeed an important factor that affects the implanting accuracy. Here, we propose a fast and concise registration method using a registration-and-fixation device as well as an adjustable handpiece for dynamic navigation in dental implant surgery. To the best of our knowledge, our work is the first study of such a registration method for dynamic navigation in a dental implant system.

Research Methods in a Multinational Business Environment and Implications for Capital Formation: Application of Cross-Sectional Autoregressive Distributed Lag Methods.

We explore whether foreign direct investment outflows augment or obstruct public or private capital in developing countries by decomposing domestic capital into private and public capital. While developed countries are the primary source of foreign direct investment outflows (FDIOs), developing economies have become the primary source of FDIO over the past 30 years. We apply cross-sectional autoregressive distributed lag (CS-ARDL) methods to overcome the issue of endogeneity and cross-sectional dependency in our dataset. This study analyzes the interaction effects of foreign direct investment and institutional quality (IQ) in promoting aggregate domestic capital formation in developing countries. Our empirical results show that FDI outflows augment private capital formation and additionally, IQ also upsurges private capital formation. Conversely, as per results, FDI outflows obstruct public capital formation, and IQ crowds out public capital formation significantly while private capital crowds out FDI inflows. As per result estimations, we notice that FDIO crowds in private capital formation, thus we conclude that the private sector controls the majority of the sectors for developing countries and the role of the public sector is quite minimal. We conclude that private and public capital possess different attributes; thus clubbing them together might result in aggregation bias. Our result estimations provide several useful policy implications.

Lipogenic stromal cells as members of the foam-cell population in human atherosclerosis: Immunocytochemical and ultrastructural assessment of 6 cases.

To identify the nature of foam cells in atherosclerosis, carotid atherosclerotic plaques (CAPs) from six patients were studied. Hematoxylin-and-eosin, Congo Red and Oil Red O staining were used to study histopathologic alterations in CAPs. CD31, α-smooth-muscle actin (α-SMA), CD68, desmin and S100 were stained immunohistochemically. The ultrastructure of foam cells was analyzed by transmission electron microscopy (TEM). CAPs were shown to be composed of a fibrous cap covering a dome-shaped mass with a peripheral, circumferential fringe merging with a basal band which itself met the tunica media, the latter consisting of smooth-muscle cells (SMCs). The interior of the dome-shaped mass exhibited fibrosis, neovascularization, hemorrhage, necrosis and calcification. Lipid droplets identified by histological stains and TEM were found in the rounded epithelioid foam cells regarded as macrophages, as well as in spindled cells interpreted here as lipoleiomyocytes (lipid-containing SMCs), lipofibroblasts and lipomyofibroblasts; and all these cells were located in different regions of the CAPs. All of these lipid-laden cells were strongly positive for CD68 but negative for desmin. Foam cells were weakly positive for α-SMA, CD31 and S100. The results indicate that the light microscopically identifiable population of foam/lipid-laden cells hide a spectrum of diverse differentiation ranging from the expected macrophage phenotype to non-macrophage phenotypes. The origin of these diverse cell phenotypes in terms of multipotential mesenchymal precursors and the origin of the intracellular lipid are discussed.

M2 macrophagy-derived exosomal miRNA-26a-5p induces osteogenic differentiation of bone mesenchymal stem cells.

BACKGROUND: Bone marrow mesenchymal stem cells have always been a heated research topic in bone tissue regeneration and repair because of their self-renewal and multi-differentiation potential. A large number of studies have been focused on finding the inducing factors that will promote the osteogenic differentiation of bone marrow mesenchymal stem cells. Previous studies have shown that macrophage exosomes or miRNA-26a-5p can make it work, but the function of this kind of substance on cell osteogenic differentiation has not been public. METHODS: M2 macrophages are obtained from IL-4 polarized bone marrow-derived macrophages. Exosomes were isolated from the supernatant of M2 macrophages and identified via transmission electron microscopy (TEM), western blotting, and DLS. Chondrogenic differentiation potential was detected by Alcian blue staining. Oil red O staining was used to detect the potential for lipogenic differentiation. And MTT would detect the proliferative capacity of cells. Western blot was performed to detect differential expression of osteogenic differentiation-related proteins. RESULTS: The results showed that M2 macrophage exosomes will promote bone differentiation and at the same time inhibit lipid differentiation. In addition, M2 macrophage-derived exosomes have the function of promoting the expression of SOX and Aggrecan suppressing the level of MMP13. The exosome inhibitor GW4689 suppresses miRNA-26a-5p in M2 macrophage exosomes, and the treated exosomes do not play an important role in promoting bone differentiation. Moreover, miRNA-26a-5p can enable to promote bone differentiation and inhibit lipid differentiation. miRNA-26a-5p can promote the expression of ALP (alkaline phosphatase), RUNX-2 (Runt-related transcription factor 2), OPN(osteopontin), and Col-2(collagen type II). Therefore, it is speculated that exosomal miRNA-26a-5p is indispensable in osteogenic differentiation. CONCLUSIONS: The present study indicated that M2 macrophage exosomes carrying miRNA-26a-5p can induce osteogenic differentiation of bone marrow-derived stem cells to inhibit lipogenic differentiation, and miRNA-26a-5p will also promote the expression of osteogenic differentiation-related proteins ALP, RUNX-2, OPN, and Col-2.

Effect of renal function on high-density lipoprotein particles in patients with coronary heart disease.

BACKGROUND: Although renal insufficiency and dyslipidemia are known to be closely associated, the effect of kidney function on the size and clinical value of high-density lipoprotein (HDL) particles remains largely unknown, especially in patients with coronary heart disease. METHODS: A total of 419 coronary heart disease patients and 105 non-coronary heart disease patients were included. HDL particle size, represented by HDL-C/apoA-I, was compared between groups stratified by estimated glomerular filtration rate (eGFR) and Gensini scores using standard Student's t test and one-way ANOVA. Pearson's correlation test was performed to analyze the association between eGFR and HDL-C/apoA-I in patients with coronary heart disease. The relationship between HDL particle size and the occurrence of coronary heart disease was explored using Univariate logistic regression analysis. RESULTS: In patients with coronary heart disease, between-group analysis revealed that HDL-C/apoA-I increased as eGFR declined, and significance appeared as eGFR declined to under 60 ml/min·1.73 m2 (P < 0.001), and Pearson's correlation test also confirmed an inverse correlation between eGFR and HDL-C/apoA-I levels in coronary heart disease patients. When stratified by Gensini scores, in coronary heart disease patients with eGFR ≥ 90 mL/(min·1.73 m2), those with higher Gensini scores had smaller HDL-C/apoA-I. However, with or without kidney insufficiency, smaller HDL-C/apoA-I was associated with a higher occurrence of coronary heart disease (P < 0.05). CONCLUSION: With the presence of renal insufficiency, HDL-C/apoA1 was higher in patients with coronary heart disease. Lower HDL-C/apoA1 was still associated with a higher occurrence of coronary heart disease, but the original association between lower HDL-C/apoA1 and more severe coronary artery stenosis was lost in patients with renal insufficiency.

Histopathological and ultrastructural study of carotid atherosclerotic plaques: a study of four cases.

To clarify the characteristics and origin of the cellular components in atherosclerosis, carotid atherosclerotic plaques (CAPs) of four patients were studied by light microscopy using hematoxylin-eosin, Congo red and alpha-smooth-muscle actin stains, and by transmission electron microscopy of different regions of CAPs. By light microscopy, CAPs were composed of 1) a fibrous cap; 2) an atherosclerotic core presenting focal fibrosis, neovascularization, hemorrhage, necrosis, chondrification and ossification; and 3) a basal band composed of a hyperplasic pseudo-media and affected tunica media. Ultrastructurally, the CAPs contained a diversity of cells including fibroblasts, myofibroblasts, osteochondrocytes, vascular smooth-muscle cells, foam cells and other myoid cells characterized by varied features of the above mentioned cells. The results indicated that CAPs were derived from a proliferation of multipotential mesenchymal stem cells, leading to the presence of degenerated foam cells and lipid-laden cells.

Forest biomass carbon pool dynamics in Tibet Autonomous Region of China: Inventory data 1999-2019.

According to the forest resources inventory data for different periods and the latest estimation parameters of forest carbon reserves in China, the carbon reserves and carbon density of forest biomass in the Tibet Autonomous Region from 1999 to 2019 were estimated using the IPCC international carbon reserves estimation model. The results showed that, during the past 20 years, the forest area, forest stock, and biomass carbon storage in Tibet have been steadily increasing, with an average annual increase of 1.85×104 hm2, 0.033×107 m3, and 0.22×107 t, respectively. Influenced by geographical conditions and the natural environment, the forest area and biomass carbon storage gradually increased from the northwest to the southeast, particularly in Linzhi and Changdu, where there are many primitive forests, which serve as important carbon sinks in Tibet. In terms of the composition of tree species, coniferous forests are dominant in Tibet, particularly those containing Abies fabri, Picea asperata, and Pinus densata, which comprise approximately 45% of the total forest area in Tibet. The ecological location of Tibet has resulted in the area being dominated by shelter forest, comprising 68.76% of the total area, 64.72% of the total forest stock, and 66.34% of the total biomass carbon reserves. The biomass carbon storage was observed to first increase and then decrease with increasing forest age, which is primarily caused by tree growth characteristics. In over-mature forests, trees' photosynthesis decreases along with their accumulation of organic matter, and the trees can die. In addition, this study also observed that the proportion of mature and over-mature forest in Tibet is excessively large, which is not conducive to the sustainable development of forestry in the region. This problem should be addressed in future management and utilization activities.