Marrow Cavity Research Articles

The Osteogenic Role of Barium Titanate/Polylactic Acid Piezoelectric Composite Membranes as Guiding Membranes for Bone Tissue Regeneration.

PurposeBiopiezoelectric materials have good biocompatibility and excellent piezoelectric properties, and they can generate local currents in vivo to restore the physiological electrical microenvironment of the defect and promote bone regeneration. Previous studies of guided bone regeneration membranes have rarely addressed the point of restoring it, so this study prepared a Barium titanate/Polylactic acid (BT/PLA) piezoelectric composite membrane and investigated its bone-formation, with a view to providing an experimental basis for clinical studies of guided bone tissue regeneration membranes.MethodsBT/PLA composite membranes with different BT ratio were prepared by solution casting method, and piezoelectric properties were performed after corona polarization treatment. The optimal BT ratio was selected and then subjected to in vitro cytological experiments and in vivo osteogenic studies in rats. The effects on adhesion, proliferation and osteogenic differentiation of the pre-osteoblastic cell line (MC3T3-E1) were investigated. The effect of composite membranes on bone repair of cranial defects in rats was investigated after 4 and 12 weeks.ResultsThe highest piezoelectric coefficient d33 were obtained when the BT content was 20%, reaching (7.03 ± 0.26) pC/N. The value could still be maintained at (4.47±0.17) pC/N after 12 weeks, meeting the piezoelectric constant range of bone. In vitro, the MC3T3-E1 cells showed better adhesion and proliferative activity in the group of polarized 20%BT. The highest alkaline phosphatase (ALP) content was observed in cells of this group. In vivo, it promoted rapid bone regeneration. At 4 weeks postoperatively, new bone formation was evident at the edges of the defect, with extensive marrow cavity formation; after 12 weeks, the defect was essentially completely closed, with density approximating normal bone tissue and significant mineralization.ConclusionThe BT/PLA piezoelectric composite membrane has good osteogenic properties and provides a new idea for guiding the research of membrane materials for bone tissue regeneration.

Intra-bone marrow injection of magnesium isoglyrrhizinate inhibits inflammation and delays osteoarthritis progression through the NF-κB pathway

ObjectiveOsteoarthritis (OA) presents cartilage damage in addition to chronic inflammation. However, self-recovery of damaged cartilage in an inflammatory environment is not possible. Mesenchymal stem cells (MSCs) in the bone marrow are a source of regenerative repair of damaged cartilage. To date, whether intra-luminal administration of the bone marrow can delay the progression of OA is still unknown. This study, therefore, aimed to explore the role of intra-bone marrow injection of Magnesium isoglycyrrhizinate (MgIG) in delaying the OA progression and to investigate the underlying mechanism.MethodsRabbit OA models were established using the anterior cruciate ligament transection method while a catheter was implanted into the bone marrow cavity. 1 week after surgery, MgIG treatment was started once a week for 4 weeks. The cartilage degradation was analyzed using hematoxylin–eosin staining, Masson’s trichrome staining and Alcian blue staining. Additionally, the pro-inflammatory factors and cartilage regeneration genes involved in the cartilage degeneration and the underlying mechanisms in OA were detected using enzyme-linked immunosorbent assay, quantitative real-time PCR (qRT-PCR) and Western blotting.ResultsThe results of histological staining revealed that intra-bone marrow injection of MgIG reduced degeneration and erosion of articular cartilage, substantially reducing the Osteoarthritis Research Society International scores. Furthermore, the productions of inflammatory cytokines in the bone marrow cavity and articular cavity such as interleukin-1β(IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) were inhibited upon the treatment of MgIG. At the same time, the expression of alkaline phosphate, tartrate-resistant acid phosphatase-5b (TRAP-5b) and C-telopeptides of type II collagen (CTX-II) in the blood also decreased and was positively correlated. On the contrary, cartilage-related genes in the bone marrow cavity such as type II collagen (Col II), Aggrecan (AGN), and SRY-box 9 (SOX9) were up-regulated, while matrix metalloproteinase-3 (MMP-3) was down-regulated. Mechanistically, MgIG was found to exert an anti-inflammatory effect and impart protection to the cartilage by inhibiting the NF-κB pathway.ConclusionIntra-bone marrow injection of MgIG might inhibit the activation of the NF-κB pathway in the progression of OA to exert an anti-inflammatory effect in the bone marrow cavity and articular cavity, thereby promoting cartilage regeneration of MSCs in the bone marrow, making it a potential new therapeutic intervention for the treatment of OA.

Tricin protects rats from ovariectomized-induced osteoporosis by enhancing Wnt/β-catenin pathway

Purpose: To investigate the effects of tricin on ovariectomized-induced osteoporosis, and unravel theunderling mechanism of action.Methods: An osteoporosis rat model was established by conducting ovariectomy (OVX). Changes in the microstructure of the trabecular bone were visualized using Hematoxylin and eosin (H&E) staining, and a three-point bending test was employed to assess the biomechanical stability of the femurs, after the administration of tricin (20 and 40 mg/kg). Subsequently, bone marrow mesenchymal stem cells (BMSCs) were isolated and treated with tricin (7 and 15 μM). Alizarin red staining was performed to assess mineralization, and Runt-related transcription factor 2 (RUNX2); osteocalcin (OCN) and collagen type I alpha 1 (Col1a1) were quantified using western blot analysis. The Wnt/β-catenin pathway related proteins, i.e., Wnt3a, β-catenin, glycogen synthase kinase-3 β (GSK-3 β) were determined.Results: Ovariectomy induced thinner and discontinuous trabecular bone, with increased marrow cavities, while application of tricin significantly improved the density and regularity meshwork, but reduced marrow cavities. Tricin also enhanced biomechanical competence as seen in the upregulated maximum load, stiffness, young modulus and maximum stress compared with OVX group (p < 0.01). Furthermore, tricin increased calcification in BMSCs, and significantly upregulated the expressions of RUNX2, OCN and COL1A1 when compared with OVX group (p < 0.01). It promoted Wnt/β-catenin signaling by enhancing Wnt3a and β-catenin, while inhibiting GSK3β expression, compared with OVX group (p < 0.05 or p < 0.01).Conclusion: Tricin exerts protective effects against OVX-induced osteoporosis by enhancing Wnt/β-catenin pathway. Thus, tricin is a potential therapeutic agent for the management of osteoporosis.

PTHrP promotes subchondral bone formation in TMJ-OA

PTH-related peptide (PTHrP) improves the bone marrow micro-environment to activate the bone-remodelling, but the coordinated regulation of PTHrP and transforming growth factor-β (TGFβ) signalling in TMJ-OA remains incompletely understood. We used disordered occlusion to establish model animals that recapitulate the ordinary clinical aetiology of TMJ-OA. Immunohistochemical and histological analyses revealed condylar fibrocartilage degeneration in model animals following disordered occlusion. TMJ-OA model animals administered intermittent PTHrP (iPTH) exhibited significantly decreased condylar cartilage degeneration. Micro-CT, histomorphometry, and Western Blot analyses disclosed that iPTH promoted subchondral bone formation in the TMJ-OA model animals. In addition, iPTH increased the number of osterix (OSX)-positive cells and osteocalcin (OCN)-positive cells in the subchondral bone marrow cavity. However, the number of osteoclasts was also increased by iPTH, indicating that subchondral bone volume increase was mainly due to the iPTH-mediated increase in the bone-formation ability of condylar subchondral bone. In vitro, PTHrP treatment increased condylar subchondral bone marrow-derived mesenchymal stem cell (SMSC) osteoblastic differentiation potential and upregulated the gene and protein expression of key regulators of osteogenesis. Furthermore, we found that PTHrP-PTH1R signalling inhibits TGFβ signalling during osteoblastic differentiation. Collectively, these data suggested that iPTH improves OA lesions by enhancing osteoblastic differentiation in subchondral bone and suppressing aberrant active TGFβ signalling. These findings indicated that PTHrP, which targets the TGFβ signalling pathway, may be an effective biological reagent to prevent and treat TMJ-OA in the clinic.

Isolation of Monocyte-Macrophage Lineage Cells from Rat Bones by Secondary Adherence Method.

With a decrease of bone mineral density, bones are more likely to fracture, thus negatively affecting a patient's quality of life. The growth and development of bones are mainly regulated by osteoblasts and osteoclasts. It has been widely accepted that osteoclasts are derived from bone marrow monocyte-macrophage cells (BMMs). BMMs and other hematopoietic stem cells are located in the bone marrow cavity. Therefore, isolating single stable BMMs from different and heterogeneous cell populations is a huge challenge. Here we present a protocol for the isolation of BMMs from SD rats, called the secondary adherence method. Adherent cells cultured for 24-48 h in primary culture were collected. Flow cytometric analysis showed that approximately 37.94% of the cells were CD11b/c+ (monocyte-macrophage surface antigen). Tartrate resistant acid phosphatase (TRAP) staining and western blot analysis demonstrated that BMMs could differentiate into osteoclasts in vitro. The above findings suggested that the secondary adherence cells could be considered as a suitable cellular model for osteoclast differentiation research.

How high-fat diet affects bone in mice: A systematic review and meta-analysis.

High-fat diet (HFD) feeding for mice is commonly used to model obesity. However, conflicting results have been reported on the relationship between HFD and bone mass. In this systematic review and meta-analysis, we synthesized data from 80 articles to determine the alterations in cortical and trabecular bone mass of femur, tibia, and vertebrae in C57BL/6 mice after HFD. Overall, we detected decreased trabecular bone mass as well as deteriorated architecture, in femur and tibia of HFD treated mice. The vertebral trabecula was also impaired, possibly due to its reshaping into a more fragmentized pattern. In addition, pooled cortical thickness declined in femur, tibia, and vertebrae. Combined with changes in other cortical parameters, HFD could lead to a larger femoral bone marrow cavity, and a thinner and more fragile cortex. Moreover, we conducted subgroup analyses to explore the influence of mice's sex and age as well as HFD's ingredients and intervention period. Based on our data, male mice or mice aged 6-12 weeks old are relatively susceptible to HFD. HFD with > 50% of energy from fats and intervention time of 10 weeks to 5 months are more likely to induce skeletal alterations. Altogether, these findings supported HFD as an appropriate model for obesity-associated bone loss and can guide future studies.

Aseptic femoral nonunion treated with exchange locked nailing with intramedullary augmentation cancellous bone graft

BackgroundClosed reamed locked intramedullary nailing has been the treatment of choice for most of femoral shaft fractures. A high union rate with a low complication rate is generally predictable. For an aseptic femoral shaft nonunion with a prior inserted intramedullary nail, exchange nailing is one of favored surgical techniques for treatment. However, a greatly varied success rate of 72–100% has been reported. To improve the success rate of exchange femur nailing, a modified bone grafting technique was developed. The purpose of this retrospective study intended to evaluate outcomes of such a revised technique.MethodsFrom July 2011 to March 2019, 48 consecutive adult patients (average, 38 years; range, 19–67 years) with aseptic femoral shaft nonunions after intramedullary nailing treatment were studied. All femoral shaft fractures were initially caused by traffic accidents, which were treated by a closed or open intramedullary nailing technique at various hospitals. The current revision treatment was performed after an average of 2.2 years (range 1.1–6.2 years) from initial injuries. In the surgery, the prior nail was removed and the marrow cavity was reamed widely (at least 2 mm as possible). Sufficient cancellous bone grafts harvested on the trochanteric marrow wall from the inside were placed in the marrow cavity of the junction of nonunion fragments. A new 1-mm smaller size locked intramedullary nail was inserted. Whether the dynamic or static mode of nails were used mainly depended on the nonunion level. Postoperatively, protected weight bearing with crutches was allowed for all patients.ResultsForty-one patients were followed for an average of 2.8 years (85.4%; range, 1.9–4.5 years) and all fractures healed. The union rate was 100% (41/41, p < 0.001) with a union time of an average of 3.4 months (range, 2.5–5.0 months). There were no complications of deep infection, nonunions, malunions, implant failures or an avulsed trochanter tip fracture. The satisfactory knee function improved from 73.2% (30/41) preoperatively to 92.7% (38/41) at the latest follow-up (p = 0.019).ConclusionsThe described modified bone grafting technique may effectively improve a union rate of exchange femur nailing while the surgical procedure is not complicated. It may therefore be used concomitantly in all aseptic femoral shaft nonunions when exchange nailing is performed.

Island perforator muscle flaps for chronic osteomyelitis of the lower extremities: a retrospective analysis of 21 consecutive cases

One of the procedures for treating chronic osteomyelitis is the management of dead space resulting from aggressive débridement of the marrow cavity. To fill the void created by débridement, various muscle flaps have been recommended by many surgeons for their convenience and antiinfective properties. The objective of this study was to evaluate the efficacy of island perforator muscle flaps for the reconstruction of chronic osteomyelitis débridement defects of the lower extremities and provide indications for the selection of the muscle flap. A retrospective review of consecutive patients with chronic osteomyelitis of the lower extremities who underwent reconstruction using the island perforator muscle flap procedure from 2015 through 2018 was conducted. Data were collected on characteristics of the patients, wound site, wound size, surgical procedure, muscle choice, and wound healing. For the 21 patients included in the study, all muscle flaps survived. Wounds healed completely within 4 weeks. No infection relapses were identified during the follow-up period of at least 12 months. Simple primary closure, with no additional incision in the donor site, was achieved in five patients. In eight patients, an additional incision was made to harvest a muscle flap, but both the wound and donor site were closed primarily. The results showed that the island perforator muscle flap is less invasive, easy to harvest, and effective, and can be a good choice for the management of dead space resulting from débridement for chronic osteomyelitis in the lower extremity. Therapeutic, IV.

Osteocyte-specific dentin matrix protein 1 : the role of mineralization regulation in low-magnitude high-frequency vibration enhanced osteoporotic fracture healing.

AimsThere is an increasing concern of osteoporotic fractures in the ageing population. Low-magnitude high-frequency vibration (LMHFV) was shown to significantly enhance osteoporotic fracture healing through alteration of osteocyte lacuno-canalicular network (LCN). Dentin matrix protein 1 (DMP1) in osteocytes is known to be responsible for maintaining the LCN and mineralization. This study aimed to investigate the role of osteocyte-specific DMP1 during osteoporotic fracture healing augmented by LMHFV.MethodsA metaphyseal fracture was created in the distal femur of ovariectomy-induced osteoporotic Sprague Dawley rats. Rats were randomized to five different groups: 1) DMP1 knockdown (KD), 2) DMP1 KD + vibration (VT), 3) Scramble + VT, 4) VT, and 5) control (CT), where KD was performed by injection of short hairpin RNA (shRNA) into marrow cavity; vibration treatment was conducted at 35 Hz, 0.3 g; 20 minutes/day, five days/week). Assessments included radiography, micro-CT, dynamic histomorphometry and immunohistochemistry on DMP1, sclerostin, E11, and fibroblast growth factor 23 (FGF23). In vitro, murine long bone osteocyte-Y4 (MLO-Y4) osteocyte-like cells were randomized as in vivo groupings. DMP1 KD was performed by transfecting cells with shRNA plasmid. Assessments included immunocytochemistry on osteocyte-specific markers as above, and mineralized nodule staining.ResultsHealing capacities in DMP1 KD groups were impaired. Results showed that DMP1 KD significantly abolished vibration-enhanced fracture healing at week 6. DMP1 KD significantly altered the expression of osteocyte-specific markers. The lower mineralization rate in DMP1 KD groups indicated that DMP1 knockdown was associated with poor fracture healing process.ConclusionThe blockage of DMP1 would impair healing outcomes and negate LMHFV-induced enhancement on fracture healing. These findings reveal the importance of DMP1 in response to the mechanical signal during osteoporotic fracture healing.Cite this article: Bone Joint Res 2022;11(7):465–476.

Progressive skeletal defects caused by Kindlin3 deficiency, a model of autosomal recessive osteopetrosis in humans.

The cellular and molecular mechanisms of bone development and homeostasis are clinically important, but not fully understood. Mutations in integrins and Kindlin3 in humans known as Leukocyte adhesion deficiencies (LAD) cause a wide spectrum of complications, including osteopetrosis. Yet, the rarity, frequent misdiagnosis, and lethality of LAD preclude mechanistic analysis of skeletal abnormalities in these patients. Here, using inducible and constitutive tissue-specific Kindlin3 knockout (K3KO) mice, we show that the constitutive lack of embryonic-Kindlin3 in myeloid lineage cells causes growth retardation, edentulism, and skull deformity indicative of hydrocephaly. Micro-CT analysis revealed craniosynostosis, choanal stenosis, and micrognathia along with other skeletal abnormalities characteristic of osteopetrosis. A marked progression of osteosclerosis occurs in mature to middle-aged adults, resulting in the narrowing of cranial nerve foramina and bone marrow cavities of long bones. However, postnatal-Kindlin3 is less critical for bone remodeling and architecture. Thus, myeloid Kindlin3 is essential for skeletal development and its deficiency leads to autosomal recessive osteopetrosis (ARO). The study will aid in the diagnosis, management, and treatment choices for patients with LAD-III and ARO.

CD137 Regulates Bone Loss via the p53 Wnt/β-Catenin Signaling Pathways in Aged Mice.

Senile osteoporosis is a chronic skeletal disease, leading to increased bone brittleness and risk of fragile fractures. With the acceleration of population aging, osteoporosis has gradually become one of the most serious and prevalent problems worldwide. Bone formation is highly dependent on the proper osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in the bone marrow microenvironment, which is generated by the functional relationship among different cell types, including osteoblasts, adipogenic cells, and bone marrow stromal cells in the bone marrow. It is still not clear how osteoporosis is caused by its molecular mechanism. With aging, bone marrow is able to restrain osteogenesis. Discovering the underlying signals that oppose BMSC osteogenic differentiation from the bone marrow microenvironment and identifying the unusual changes in BMSCs with aging is important to elucidate possible mechanisms of senile osteoporosis. We used 3 gene expression profiles (GSE35956, GSE35957, and GSE35959) associated with osteoporosis. And a protein-protein interaction (PPI) network was also built to identify the promising gene CD137. After that, we performed in vivo experiments to verify its function and mechanism. In this experiment, we found that significant bone loss was observed in aged (18-month-old) mice compared with young (6-month-old) mice. The adipose tissue in bone marrow cavity from aged mice reached above 10 times more than young mice. Combining bioinformatics analysis and vivo experiments, we inferred that CD137 might be involved in the p53 and canonical Wnt/β-catenin signaling pathways and thereby influenced bone mass through regulation of marrow adipogenesis. Importantly, osteoporosis can be rescued by blocking CD137 signaling in vivo. Our research will contribute to our understanding not only of the pathogenesis of age-related bone loss but also to the identification of new targets for treating senile osteoporosis.

Pelvic U-Net: multi-label semantic segmentation of pelvic organs at risk for radiation therapy anal cancer patients using a deeply supervised shuffle attention convolutional neural network

BackgroundDelineation of organs at risk (OAR) for anal cancer radiation therapy treatment planning is a manual and time-consuming process. Deep learning-based methods can accelerate and partially automate this task. The aim of this study was to develop and evaluate a deep learning model for automated and improved segmentations of OAR in the pelvic region.MethodsA 3D, deeply supervised U-Net architecture with shuffle attention, referred to as Pelvic U-Net, was trained on 143 computed tomography (CT) volumes, to segment OAR in the pelvic region, such as total bone marrow, rectum, bladder, and bowel structures. Model predictions were evaluated on an independent test dataset (n = 15) using the Dice similarity coefficient (DSC), the 95th percentile of the Hausdorff distance (HD95), and the mean surface distance (MSD). In addition, three experienced radiation oncologists rated model predictions on a scale between 1–4 (excellent, good, acceptable, not acceptable). Model performance was also evaluated with respect to segmentation time, by comparing complete manual delineation time against model prediction time without and with manual correction of the predictions. Furthermore, dosimetric implications to treatment plans were evaluated using different dose-volume histogram (DVH) indices.ResultsWithout any manual corrections, mean DSC values of 97%, 87% and 94% were found for total bone marrow, rectum, and bladder. Mean DSC values for bowel cavity, all bowel, small bowel, and large bowel were 95%, 91%, 87% and 81%, respectively. Total bone marrow, bladder, and bowel cavity segmentations derived from our model were rated excellent (89%, 93%, 42%), good (9%, 5%, 42%), or acceptable (2%, 2%, 16%) on average. For almost all the evaluated DVH indices, no significant difference between model predictions and manual delineations was found. Delineation time per patient could be reduced from 40 to 12 min, including manual corrections of model predictions, and to 4 min without corrections.ConclusionsOur Pelvic U-Net led to credible and clinically applicable OAR segmentations and showed improved performance compared to previous studies. Even though manual adjustments were needed for some predicted structures, segmentation time could be reduced by 70% on average. This allows for an accelerated radiation therapy treatment planning workflow for anal cancer patients.

The effect of Rutin hydrate on Glucocorticoids induced osteoporosis in mandibular alveolar bone in Albino rats (Radiological, histological and histochemical study)

BackgroundGlucocorticoids are used in different conditions such as autoimmune disorders and organ transplantation and their administration is the most common cause of secondary osteoporosis. Rutin is a flavonoid found in many plants. Flavonoids are natural products with various therapeutic and biological effects. ObjectiveIs to investigate the effect of Rutin Hydrate as a form of Rutin on glucocorticoid induced osteoporosis in mandibular alveolar bone radiologically, histologically and histochemically. MethodsTwenty-one adult male Albino rats were randomly divided into three groups. Group I (control), group II (osteoporotic) and group III (Rutin Hydrate treated). In both group II and III rats received 21 mg/kg of methylprednisolone daily for four weeks. Then group III received 50 mg/kg of rutin hydrate in distilled water daily for another four weeks. At the end of the experiment, mandibles were dissected for radiographic assessment, then processed for histological and histochemical examination and statistical analysis. ResultsRadiologically, administration of Rutin Hydrate was able to enhance bone density than osteoporotic group. Histological examination revealed preserved cortical bone thickness that had been statistically proved. Apparently normal sized marrow cavities, some plump osteoblasts and normal osteocytes were seen in group III. Histochemical examination showed statistical increase in the area percentage of newly formed collagen in group III than group II. ConclusionsRutin Hydrate was able to modify the radiological and histological picture of osteoporotic alveolar bone. This was achieved by the ability of Rutin Hydrate to increase bone density, preserve cortical plates thickness and enhance new collagen formation that was proved histochemically.

Age and Body Growth of the Tokay Gecko, &lt;i&gt;Gekko gecko&lt;/i&gt; (Linnaeus, 1758), Studied by the Skeletochronological Method

Tokay gecko, Gekko gecko (Linnaeus, 1758) is highly exploited in Java for human consumption in China. Using skeletochronology, the age and body growth of Tokay Geckos from local populations in Central Java (18 females, 21 males) and in East Java (19 females, 42 males) were studied for the first time. A total of 100 frozen specimens (37 females, 63 males) were used. Sex was determined by observing the presence (male) or absence of pre-anal pores (female). Snout to vent length (SVL) of the smallest female and male with the line of arrested growth (LAG) was 127.1 and 160.4 mm, respectively. Both males and females reach sexual maturity before one year old with 98.3 mm SVL for females and 111.6 mm SVL for males. Analysis of the LAG counts indicated that the age of individuals that were harvested was ranged 0 – 2 years for females and males, with SVL ranging 110 – 182 mm. Growth rates in SVL are much faster in males as compared to females, as well as increasing of MP (width of bone from the edge of marrow cavity to the periosteal outer margin) inside femur bone. The mean SVL of males was larger than that of females. The Sexual Dimorphism Index (SDI) was calculated as -0.28, indicating a sexual size dimorphism in favor of males.

Creation and application of war trauma treatment simulation software for first aid on the battlefield based on undeformed high-resolution sectional anatomical image (Chinese Visible Human dataset)

BackgroundEffective first aid on the battlefield is vital to minimize deaths caused by war trauma and improve combat effectiveness. However, it is difficult for junior medical students, which have relatively poor human anatomy knowledge and first aid experience. Therefore, we aim to create a treatment simulation software for war trauma, and to explore its application for first aid training.Methods This study is a quantitative post-positivist study using a survey for data collection. First, high-resolution, thin-sectional anatomical images (Chinese Visible Human (CVH) dataset) were used to reconstruct three-dimensional (3D) wound models. Then, the simulation system and the corresponding interactive 3D-PDF, including 3D models, graphic explanation, and teaching videos, were built, and used for first aid training in army medical college. Finally, the interface, war trauma modules, and training effects were evaluated using a five-point Likert scale questionnaire. All measurements are represented as mean and standard deviations. Moreover, free text comments from questionnaires were collected and aggregated.ResultsThe simulation software and interactive 3D-PDF were established. This included pressure hemostasis of the vertex, face, head-shoulder, shoulder-arm, upper forearm, lower limb, foot, and punctures of the cricothyroid membrane, pneumothorax, and marrow cavity. Seventy-eight medical students participated in the training and completed the questionnaire, including 66 junior college students and 12 graduate students. The results indicated that they were highly satisfied with the software (score: 4.64 ± 0.56). The systems were user-friendly (score: 4.40 ± 0.61) and easy to operate (score: 4.49 ± 0.68). The 3D models, knowledge of hemostasis, and puncture were accurate (scores: 4.41 ± 0.67, and 4.53 ± 0.69) and easily adopted (scores: 4.54 ± 0.635, and 4.40 ± 0.648). They provided information about hemostasis and puncture (all scores > 4.40), except for cricothyroid membrane puncture (scores: 4.39 ± 0.61), improved the learning enthusiasm of medical students (score: 4.55 ± 0.549), and increased learning interest (score: 4.54 ± 0.57).ConclusionOur software can effectively help medical students master first aid skills including hemostasis, cricothyroid membrane and bone marrow puncture, and its anatomy. This may also be used for soldiers and national first aid training.

ALPK1 Aggravates TMJOA Cartilage Degradation via NF-κB and ERK1/2 Signaling

Temporomandibular joint osteoarthritis (TMJOA) is a common degenerative joint disease without effective intervention strategies. Previous research implied that alpha-kinase 1 (ALPK1) is involved in the inflammatory responses of gout, a chronic arthritis. Herein, we found the main distribution of ALPK1 in a proliferative layer of condylar cartilage and marrow cavity of subchondral bone, as well as a lining layer of synovial tissues in human temporomandibular joint. Moreover, the expression of ALPK1 was augmented in degraded condylar cartilage of monosodium iodoacetate (MIA)–induced TMJOA mice. After MIA induction, ALPK1 knockout mice exhibited attenuated damage of cartilage and subchondral bone, as well as synovitis, as compared with wide type mice. In contrast, intra-articular administration of recombinant human ALPK1 aggravated the pathology of MIA-induced TMJOA. Furthermore, ex vivo study demonstrated that ALPK1 exacerbated chondrocyte catabolism by upregulating matrix metalloproteinase 13 and cyclooxygenase 2 by activating NF-κB (nuclear factor–kappaB) signaling and suppressed anabolism by downregulating aggrecan by inhibiting ERK1/2 (extracellular signal–regulated kinase 1/2) in articular chondrocytes. Taken together, ALPK1 exacerbates the degradation of condylar cartilage during TMJOA through the NF-κB and ERK1/2 signaling pathway. This study provides a new insight regarding the role of ALPK1 during TMJOA pathology.

Characteristics and significance of T lymphocyte subsets in peripheral blood of osteosarcoma mice.

BackgroundOsteosarcoma (OS) is the most common malignant bone tumor, which often has lung metastasis. The survival rate after tumor metastasis is very low. Treatments including the antitumor immunocompetence of innate immune cells are found favorable for OS tumor. However, as a major means of early tumor detection, there are still few studies on T cells in peripheral blood of OS patients.MethodsOS cells were implanted into the femoral bone marrow cavity of C3H/HeN mice to construct OS model. The proportion of T lymphocyte subsets in peripheral blood of mice was detected by flow cytometry on the 14th and 21st days after modeling.ResultsCompared with sham operation group, on the 14th day after operation, the proportion of γδT cells and CD4+ regulatory T cells (Tregs) showed significantly higher level while other subsets didn’t have obvious difference. On the 21st day after operation, the proportion of CD3+ T cells, γδ T cells, CD4+ Tregs and Tregs/Th17 ratio were obviously higher than that of sham operation group. Meanwhile, while CD4+ T cells and CD8+ T cells were lower, suggesting the happen of peripheral immunosuppression. Comparing the T lymphocytes subsets on the 14th and 21st day after modeling in the tumor group, it was found that CD3+ T cells and CD4+ Tregs on the 21st day after modeling were significantly higher than those on the 14th day while CD4+ T cells, CD8+ T cells decreased significantly, indicating the changes of T lymphocytes in peripheral blood of OS mice are related to tumor development.ConclusionsThe formation and development of femoral OS is accompanied by the disorder of peripheral blood T lymphocyte subsets and peripheral immunosuppression.

Factor analysis of effective platelet-producing ability of fetal liver-derived cells

Objective: To study the different factors affecting platelet production post transplantation of hematopoietic stem cells (HSCs) isolated from different sources in order to explore novel options for treating platelet depletion following HSCs transplantation. Methods: HSCs and their downstream derivatives including myeloid and lymphoid cells (i.e., collective of mononuclear cells (MNCs)), were isolated from E14.5 fetal liver (FL) and bone marrow (BM) of 8-week-old mice by Ficoll separation technique. These cells were subsequently transplanted into the tibia bone marrow cavity of recipient mice post lethal myeloablative treatment in order to construct the FL-MNCs and BM-MNCs transplantation mouse model. Routine blood indices were examined in these recipient mice. The chimeric rate of donor cells in recipient peripheral blood cells were determined by flow cytometry. Different groups of cells involved in platelet reconstruction were analyzed. CD41+megakaryocytes were sorted from fetal liver or bone marrow using magnetic beads, which were then induced to differentiate into platelets in an in vitro assay. Quantitative RT-PCR was used to detect the expression of platelet-related genes in CD41+megakaryocytes from the two sources. Results: Both the FL-MNCs and the BM-MNCs transplantation groups resumed normal hematopoiesis at the 4th week after transplantation, and the blood cells of the recipient mice were largely replaced by the donor cells. Compared with the mice transplanted with BM-MNCs, the platelet level of mice transplanted with FL-MNCs recovered faster and were maintained at a higher level. At week 4, the PLT level of the FL-MNCs group was (1.45±0.37)×1012/L, and of the BM-MNCs group was (1.22±0.24)×1012/L, P<0.05. The FL-MNCs contain a higher proportion of hematopoietic stem cells (Lin-Sca-1+c-Kit+)(7.60%±1.40%) compared to the BM-MNCs (1.10%±0.46%), P<0.01; the proportion of the megakaryocyte progenitor cells (Lin-Sca-1-c-Kit+CD41+CD150+) and mature megakaryocyte cells (CD41+CD42b+), also differ significantly between the FL-MNCs (3.05%±0.22%, 1.60%±0.06%, respectively) and the BM-MNCs (0.15%±0.02%, 0.87%±0.11%, respectively) groups, both P<0.01. In vitro functional studies showed that FL-MNCs-CD41+megakaryocytes could produce proplatelet-like cells more quickly after induction, with proplatelet-like cells formation on day 3 and significant platelet-like particle formation on day 5, in contrast to bone marrow-derived BM-MNCs-CD41+megakaryocytes that failed to form proplatelet-like cell on day 5. In addition, FL-MNCs-CD41+cells expressed higher levels of platelet-related genes, Mpl (3.25-fold), Fog1 (3-fold), and Gata1 (1.5-fold) (P<0.05). Conclusion: Compared with the BM-MNCs group, the FL-MNCs transplantation group appears to have a more efficient platelet implantation effect in the HSCs transplantation recipient in vivo, as well as a higher platelet differentiation rate in vitro. This might be related to a higher proportion of megakaryocytes and higher expression levels of genes such as Mpl, Fog1, and Gata1 that could be important for platelet formation in FL-MNCs-CD41+cells. Further exploration of the specific functions of these genes and the characteristics of the different proportions of the donor cells will provide valuable clues for the future treatment of platelets reconstitution after HSCs transplantation clinically.

Effects of non-muscle myosin Ⅱ silenced bone marrow-derived mesenchymal stem cells transplantation on lung extracellular matrix in rats after endotoxin/lipopolysaccharide-induced acute lung injury

Effects of non-muscle myosin Ⅱ silenced bone marrow-derived mesenchymal stem cells transplantation on lung extracellular matrix in rats after endotoxin/lipopolysaccharide-induced acute lung injury

Upregulation of Runt related transcription factor 1 (RUNX1) contributes to tendon–bone healing after anterior cruciate ligament reconstruction using bone mesenchymal stem cells

BackgroundAnterior cruciate ligament (ACL) injury could lead to functional impairment along with disabilities. ACL reconstruction often fails owing to the regeneration failure of tendon–bone interface. Herein, we aimed to investigate the effects of Runt related transcription factor 1 (RUNX1) on tendon–bone healing after ACL reconstruction using bone mesenchymal stem cells (BMSCs).MethodsBMSCs were isolated from the marrow cavity of rat femur, followed by the modification of RUNX1 with lentiviral system. Then, an ACL reconstruction model of rats was established with autografts.ResultsResults of flow cytometry exhibited positive-antigen CD44 and CD90, as well as negative-antigen CD34 and CD45 of the BMSCs. Then, we found that RUNX1-upregulated BMSCs elevated the decreased biomechanical strength of the tendon grafts after ACL reconstruction. Moreover, based on the histological observation, upregulation of RUNX1 was linked with better recovery around the bone tunnel, a tighter tendon–bone interface, and more collagen fibers compared to the group of BMSCs infected with LV-NC. Next, RUNX1-upregulated BMSCs promoted osteogenesis after ACL reconstruction, as evidenced by the mitigation of severe loss and erosion of the cartilage and bone in the tibial and femur area, as well as the increased number of osteoblasts identified by the upregulation of alkaline phosphatase, osteocalcin, and osteopontin in the tendon–bone interface.ConclusionElevated expression of RUNX1 contributed to tendon–bone healing after ACL reconstruction using BMSCs.