CD38 Drives Progress of Osteoarthritis by Affecting Cartilage Homeostasis.

OBJECTIVE: To observe expression of CD38, a key modulator of nicotinamide dinucleotide (NAD+) metabolism in mice with knee osteoarthritis, and protective effect of CD38 inhibition during the osteoarthritis (OA) development. METHOD: The destabilization of the medial meniscus (DMM) model was performed in mice to mimic the process of OA. Immunofluorescence of CD38 was performed to evaluate its response during the OA process. Limb bud-derived mesenchymal cells were isolated for micromass culture. 100 nM or 1 µM CD38 inhibitor (78c) treatment for 14 days and CD38 sgRNA infection were then used to explore the effects of chondrogenic differentiation via Alcian blue staining. The expressions of chondrogenic markers were detected using RT-PCR and Western blot. To explore the protective effect of CD38 inhibitor on cartilage degradation during OA in vivo, a CD38 inhibitor was injected into the knee joint after DMM operations. Micro-CT analysis and Safranin O-fast green staining were used to evaluate subchondral bone micro-architecture changes and cartilage degeneration. RESULTS: Compared to the control group, the CD38 expression in superficial cartilage was obviously increased in DMM group (P < 0.05). During the normal chondrogenic differentiation, the extracellular matrix formed and expression of Sox9, Col2, aggrecan increased apparently while CD38 expression decreased, which could be reversed with ablation of CD38 in limb bud-derived mesenchymal cells. Consistent with findings in vitro, CD38 blockage via CD38 inhibitor injection protected against osteosclerosis in medial subchondral bone and cartilage degeneration in DMM-induced experimental mice. Compared to the Sham group, DMM mice showed significantly increased values of BV and BV/TV in subchondral bone (P < 0.05) and Mankin score, which could be rescued by 78c treatment (P < 0.05). Also the CD38 inhibitor contributed to homeostasis of anabolism and catabolism by upregulating Sox9, Col2, aggrecan and downregulating Runx2, Col10 and Mmp13. CONCLUSION: This study primarily implicates CD38 as an important regulator of chondrogenic differentiation. Inhibition of CD38 demonstrated protection against cartilage degeneration, which suggests that CD38 could be a potential therapeutic target for OA.

[Genomics study of steroid induced femoral head necrosis of rats].

OBJECTIVES: To identify significantly differentially expression genes of steroid-induced femoral head necrosis (SINFH) of rats by gene chip, and to find out the potential factors and molecular mechanisms that oxidative stress originate or strengthen the SINFH. METHODS: Twenty Wistar rats were divided into experimental group and control group randomly. E. coli endotoxin was given to all rats at a dose of 20 µg/kg body weight by daily i.p. for two times. Then methylprednisolone (40 mg/kg) or saline was daily injected into the left gluteus muscle of the rats in experimental group and control group respectively. Six weeks later, the mRNA was extracted from the femoral head of rats in every group, and the cDNA were obtained by inverse transcript, then carried out microarray detection. The quantitative RT-PCR was used to confirm the result of microarray, and the differentially expressed genes were analyzed for the functional annotation by gene ontology (GO). RESULTS: Compared to the control group, 190 genes in the experimental group were differentially expressed, with 52 up-regulated and 138 down-regulated. Of these genes, 102 are known (have deposited in GeneBank), while 88 of them are unknown. The known genes can be divided into several families according to their biological functions, such as: oxidative stress, apoptosis, signal transduction, angiogenesis, extracellular matrix, lipid metabolism, and gene transcription related genes. The results of quantitative RT-PCR are consistent with gene-chip results. CONCLUSIONS: The occurrence of SINFH is a complicated process affected by multiple factors and signaling pathways. Our findings indicate that many genes which are involved in different signaling pathways were differentially expressed between SINFH rats and normal rats.

[Role of ATP6V1H gene in bone metabolism].

Osteoporosis is one of the common clinical orthopedic diseases, which can lead to a variety of complications. There are many pathogenic factors in this disease. The latest research found that ATP6V1H is a new gene leading to the occurrence of osteoporosis, and it is likely to become a new target for the future drug treatment of osteoporosis.This paper introduces the biological structure and characteristics of H subunit, summed up the human body caused by loss of ATP6V1H and animal models such as zebrafish, mice bone loss and osteoporosis symptom such as related research reports of the loss, from osteoclast, osteoblast and marrow stromal cell level and the connection between the various subunits further expounds the H subunit regulate bone dynamic balance of mechanism, to explore ATP6V1H in bone developmentand bone related diseases has laid a solid foundation, also provide new ideas for clinical treatment of osteoporosis.

[Progress on the treatment of adolescent idiopathic scoliosis].

Adolescent idiopathic scoliosis (AIS) is a common disease with the age of 10 to 18 years, the Cobb angle more than 10 ° on the coronal plane and combined with the rotation of the vertebral body without other organic lesions. The disease can lead to deformity, pain and even damage of cardiopulmonary function, which seriously affects the physical and mental health and quality of life of patients. For mild to moderate AIS patients, regular observation, braces and other conservative treatment methods can effectively delay the progress of scoliosis. For AIS patients whose conservative treatment is ineffective and reaches the surgical threshold, surgery is recommended. Currently, the prevalent surgical method is posterior vertebral body fusion represented by the pedicle screw internal fixation system, which can often achieve good clinical efficacy. In recent years, Physical Therapeutic Scoliosis Specific Exercise (PSSE) has become more and more popular because of its safety and effectiveness. At present, the specific indications for the treatment of AIS patients are gradually improving, the concept and technology of treatment are constantly updated, and the clinical efficacy is constantly improved. This article will start from two aspects of conservative treatment and surgical treatment, mainly describes the commonly used treatment methods in clinical progress and application as well as the problems faced, in order to provide a reference for the selection of clinical treatment.

Factors associated with preferences for elderly care mode and choice of caregivers among parents who lost their only child in a central China city.

AIM: It is forecasted that the figure of families in China who lost their only child will reach 10 million by 2035. Traditional Chinese culture places these families in a particularly disadvantaged position for elderly care. It is quite important to understand the elderly care needs of the parents. METHODS: The cluster sampling method was used to select the parents who lost their only child in Wuhu city, China. Univariate and multivariate logistic regression analysis models were carried out to analyze factors influencing the parents' preferences for elderly care mode and choice of caregivers. RESULTS: The Geriatric Depression Scale score (P < 0.001) was significantly associated with the parents' preferences for elderly care mode. Parents with different sex, marital status and grandchildren status had different preferences for their choice of caregivers. The number of chronic diseases and Geriatric Depression Scale scores were significantly associated with preferences for choice of caregivers. CONCLUSIONS: These parents should have a preferential policy of check in to a nursing home and simplify the check-in procedure. The parents should receive prompt for depression and stay in the community for elderly care. The government should guarantee that spouseless parents have priority in enjoying nurse/nursing home worker services. The government should support the development of volunteer services. Geriatr Gerontol Int 2020; 20: 112-117.

[Application status of 3D printing patient-specific instrumentation in total knee arthroplasty].

Recently, the joint replacement has gradually become a common operation of orthopedics. It's also the hot spot in current investigations. The increasing number of reports about the 3D printing technology such as patient-specific instrumentation(PSI) is applied to hip and knee replacement. It plays an important role in supporting operation especially for complex cases. However, it is still at the primary stage. This article reviews the relevant literature, analyzes and collates the research status of the application of 3D printing PSI in total knee arthroplasty, and summarizes its effectiveness in the application of knee arthroplasty from the aspects of individual preoperative planning, intraoperative operation and postoperative functional recovery, especially complex knee surgery such as obesity and knee deformity. The necessity of clinical application is discussed, and the existing problems and controversies in the current clinical application are summarized in order to provide references for the future research direction and clinical application.

A Comparative Study on the Health Status and Behavioral Lifestyle of Centenarians and Non-centenarians in Zhejiang Province, China-A Cross-Sectional Study.

Background: The growth rate of centenarians was unusually rapid in recent decades, ushering in an era of longevity. This study aims to explore the difference between centenarians and non-centenarians using quantitative research, and to scientifically guide residents to develop the correct lifestyle and health care ways. Methods: From October 2013 to August 2017. A cross-sectional survey was conducted on 271 centenarians and 570 non-centenarians by using a questionnaire to assess longevity and health issues which was developed for the needs of the study, who came from 29 counties and districts in 11 cities of Zhejiang province, China. Two hundred and fifty-five valid questionnaires were returned, with an effective response rate of 94.1%. Meanwhile, data of 526 non-centenarians from Zhejiang province was collected as a control group, with an effective response rate of 92.3%. Results: The prevalence rates of tumor, stomach and duodenal ulcer, diabetes, bronchial asthma, and chronic obstructive pulmonary disease, tuberculosis among centenarians were all lower than those among non-centenarians. The oral health of centenarians is better than that of non-centenarians. The consumption of coarse cereals, pasta, other staple foods and fruits among centenarians was higher than that of non-centenarians. The percentage of centenarians who smoke or engage in recreational activities every day was lower than that of non-centenarians. Conclusions: We should give full play to the role of preventive medicine and health management to safeguard the health of residents. Pay attention to oral health, and develop the good habit of loving teeth. The diet should be rich and varied, and increase the intake of grains and fruits. Give up smoking, limit alcohol, spirit-preserving with calming, follow the law of scientific regimen.

[Comparative study on infection rate of different adeno-associated virus for knee joint cartilage in mice].

OBJECTIVE: To explore infection rate of different adeno-associated virus (AAV) on knee joint cartilage in mice and to find a good gene editing tool for mice chondrocytes of knee joint. METHODS: Forty-five 4-week-old SPF C57BL/6 weighed(14.3±0.2) g were selected. According to different injections(6 µl) for right knee joint, mice were divided into 9 different groups, 5 mice in each group. The groups were such as following:control group (normal saline), Vigene 2 group (AAV2 from vigene biosciences, titer for 1×10¹³ vg/ml), Vigene 5 group (AAV5 from vigene biosciences, titer for 1×10¹³ vg/ml), Vigene 6 group (AAV6 from vigene biosciences, titer for 1×10¹³ vg/ml), Vigene 7 group (AAV7 from vigene biosciences, titer for 1×10¹³ vg/ml), Vigene 8 group (AAV8 from vigene biosciences, titer for 1×10¹³ vg/ml), Vigene 9 group (AAV9 from vigene biosciences, titer for 1×10¹³ vg/ml), Hanbio DJ group(AAV2-DJ from Hanbio, titer for 1×10¹² vg/ml), Hanbio 5 group (AAV5 from Hanbio, titer for 1×10¹² vg/ml). All AAVs were over-expressed green fluorescent protein(GFP). Knee joint specimens were taken and observed injury of cartilage under stereomicroscope at 30 days after injection, then 10 µm thick frozen sections were prepared. Distribution of green fluorescent protein of meniscus and cartilage of knee joint was observed under fluorescence microscope. RESULTS: Stereomicroscope observation indicated that no obvious lesion was observed in knee joint cartilage of mice after intra-articular injection of AAV. According to frozen sections of knee joints, strong green fluorescence was observed in knee joint cartilage in all AAV experimental groups. Compared with other groups, significantly stronger green fluorescence were observed both in AAV2 and AAV7 groups, whose average fluorescence density was 0.077±0.020 and 0.061±0.022. There were significant differences between two groups and other groups. CONCLUSIONS: AAV could infect chondrocyte of knee joint in vivo by injecting into knee joint cavity. Higher infection efficiency of AAV2 and AAV7 on knee joint cartilage were observed. Local injection of AAV into knee joint cavity could be used as an effective tool for gene editing of knee joint chondrocyte.

[Research status of correlation between type IX collagen gene and musculoskeletal diseases].

As an important component of articular cartilage, type IX collagen plays an important role in regulating homeostasis of bone and cartilage. The mutation or deletion of gene could disequilibrate homeostasis leads to deformity of corresponding bone and joint, and finally causes multiple epiphyseal dysplasia. Moreover, anatomic variation also leads to biomechanics change of corresponding functional unit, combine with micro-environment change caused by change of genes, osteoarthritis and disc degeneration were occurred under the function of stress over and over again. In addition, lack of type IX collagen could effect repair of articular cartilage, intervertebral disc tissue injury. However, musculoskeletal diseases related with type IX collagen has so much not limited this, the reports about it is less for lack of evidence, and need further work to study. Clear relationship of type IX collagen and its disease could provide an effective diagnostic method, and develop a new pathway for follow-up treatment.

[Clinical diagnosis and treatment for iliotibial band syndrome].

As an usually occurs in athletes, iliotibial band syndrome is payed more attention for people, the disease is diagnosed mainly by clinical symptoms, physical examination and MRI, but there is no uniform diagnostic criteria. The pathogenesis of iliotibial band syndrome is considered to be related to pressure and friction factors. As for the treatment, manipulation, muscle exercise, mainly drugs and physical therapy and so on both at home and abroad are recognized to use to achieve desired effect. For conservative failure, refractory iliotibial band syndrome patients, arthroscopy, or release of iliotibial band syndrome surgery are performed. While conservative local drug injection combined with muscle exercise could play a role in pain management besides, arthroscopic as operation method is more advanced, and applicable to all types of patients without absolute contraindication, so it is helpful for patients with early activity. At present, there is still a great deal of controversy about its pathogenesis, and there is no obvious limit for the specific indications of its various therapies in clinic, so it needs further specification.

Accumulated Spinal Axial Biomechanical Loading Induces Degeneration in Intervertebral Disc of Mice Lumbar Spine.

OBJECTIVE: To investigate the effect of accumulated spinal axial biomechanical loading on mice lumbar disc and the feasibility of applying this method to establish a mice intervertebral disc degeneration model using a custom-made hot plate cage. In previous studies, we observed that the motion pattern of mice was greatly similar to that of humans when they were standing and jumping on their lower limbs. There is little data to demonstrate whether or not accumulated spinal axial biomechanical loading could induce intervertebral disc degeneration in vivo. METHODS: Twenty-four 0-week-old mice were randomly divided into model 1-month and 3-month groups, and control 1-month and 3-month groups (n = 6 per group). The model groups was transferred into the custom-made hot plate cage three times per day for modeling. The control group was kept in a regular cage. The intervertebral disc samples of the L3 -L5 were harvested for histologic, molecular, and immunohistochemical studies after modeling for 1 and 3 months. RESULTS: Accumulated spinal axial biomechanical loading affects the histologic, molecular, and immunohistochemical changes of mice L3- L5 intervertebral discs. Decreased height of disc and endplate, fissures of annulus fibrosus, and ossification of cartilage endplate were found in morphological studies. Immunohistochemical studies of the protein level showed a similar expression of type II collagen at 1 month, but a slightly decreased expression at 3 months, and an increased expression level of type X collagen and matrix metalloproteinase 13 (MMP13). Molecular studies showed that ColIIa1 and aggrecan mRNA expression levels were slightly increased at 1 month (P > 0.05), but then decreased slightly (P > 0.05). ColXa1, ADAMTS-5, and MMP-13 expression levels werer increased both at 1 and 3 months (P < 0.05). In addition, increased expression of Runx2 was observed. CONCLUSION: Accumulated spinal axial loading provided by a custom-made hot plate accelerated mice lumbar disc and especially endplate degeneration. However, this method requires further development to establish a lumbar disc degeneration model.

Minimally invasive percutaneous plate osteosynthesis through fracture site approach for fracture of both tibia and fibula.

OBJECTIVE: To introduce the experience of treating fracture of both tibia and fibula with micro-invasive percutaneous plate internal fixation through fracture site approach. METHODS: The data of 15 patients (11 males and 4 females), including 14 adults (aged 22-73 years, mean equal to 40 years) and 1 child (aged 10 years), with fracture of both tibia and fibula were studied retrospectively in this study. A small incision was made at the fracture site of tibia. Then reposition was made under direct vision, and internal fixation was employed with steel plates inserting through the small incision. RESULTS: Anatomical reduction was obtained. No complication was found. Union occurred on time in 14 patients. One case healed after a second operation. CONCLUSIONS: Micro-invasive percutaneous plate internal fixation is beneficial to the healing of bone and soft tissues. Without X-ray examination, it is also easy to reach anatomical reduction and make tibial internal fixation with both plates with micro-invasive percutaneous plate internal fixation.

[Subculture, cryopreservation and recovery of osteoclasts].

OBJECTIVE: To explore the feasibility of passage, cryopreservation, and recovery of osteoclasts in order to develop new techniques facilitating osteoclast research. METHODS: Passage of osteoclasts: adult male SD rat(SPF grade, weight of 250 g) was sacrificed and the abdominal aorta was exposed for blood draw. Monocytes isolated from peripheral circulation was treated with RANKL and M-CSF for 2 weeks. After formation of osteoclasts, they were trypsinized with pipetting, centrifuged, re-suspended with α-MEM containing RANKL and M-CSF, and cultured in 6 well-plates and 35 mm culture dishes. Freezing of osteoclasts: trypsinized osteoclasts were centrifuged and resuspended with DMSO, FBS, α-MEM (1:2:7), and were stored in liquid nitrogen(-196 °C). Recovery of osteoclasts: frozen osteoclasts were taken out of liquid nitrogen tank and thawed quickly at 37 °C in water bath. After wash with PBS, the cells were resuspended with α-MEM containing RANKL and M-CSF, and were cultured in 6 well dishes and 35 mm culture dishes. Meanwhile, cells were checked with inverted phase contrast microscope and observed in the live cell station for real time imaging. TRAP staining was performed 3 days after plating. RESULTS: Trypsinization together with pipetting and shaking can detach the adherent osteoclasts, and the resuspended cells can be used for passage and storage in liquid nitrogen. The passaged cells became fully attached to the culture dishes in 2 hours, and the multinucleated feature could be clearly seen. The osteoclasts recovered from liquid nitrogen could completely spread out for 2 to 3 hours so that the multinucleated cells were clearly seen. These cells were still TRAP positive. CONCLUSIONS: Although osteoclasts strongly adhere to the bottom of culture dishes, a large majority of the osteoclasts can be detached after appropriate digestion with trypsin, pipetting and shaking. These cells can be used for passage and cryopreservation. After recovering from liquid nitrogen, these cells still preserve the viability and the feature of osteoclasts. The results provide a new and powerful tool for future study of osteoclast biology.

[Effect of jingui shenqi pill on morphology of injured spinal cell apoptosis in rats caused by brachytherapy].

OBJECTIVE: To study the effect of Jingui Shenqi Pill (JSP) on morphology of spinal cell apoptosis in rats injured by 192Ir irradiation. METHODS: One hundred and twenty rats were randomly divided into four groups: the model group, the JSP group, the prednisone group and the normal group. Corresponding pharmaceutics were given to rats once a day for 14 days respectively. Then except rats in the normal group, the others received 192Ir interstitial irradiation with the dosage of 22 Gy using back-fixing technology. The injured segments of spinal cord were taken out for HE staining, TUNEL examination and observation with electron microscope 8 hrs, 24 hrs and 4 weeks after irradiation. RESULTS: HE staining examination showed no obvious histological change in rats 8 and 24 hrs after irradiation, but pathological changes, as tissue rarefaction and hemorrhage did found in white matter of spinal cord shown by TUNEL 4 weeks later. Electron microscopic examination and TUNEL staining showed that as compared with the model group, the apoptotic index in the JSP and predinisone treated groups was significantly lower (P < 0.01) 8 hrs after radiation, but it showed insignificant difference between groups at the time points of 24 hrs and 4 weeks after radiation (P > 0.05). CONCLUSION: JSP could act against apoptosis of gliocyte in spinal cord of rats in early stage after brachytherapy, indicating that JSP possessing a prednisone-like action.

[Internal fixation with lag screws plus an anti-sliding plate for the treatment of Hoffa fracture of the lateral femoral condyle].

OBJECTIVE: To explore the clinical effects of internal fixation with lag screws plus an anti-sliding plate for the treatment of Hoffa fractures of the lateral femoral condyle. METHODS: From May 2006 to May 2014, 17 patients with Hoffa fractures of the lateral femoral condyle were treated with lag screws plus an anti-sliding plate. There were 13 males and 4 females, ranging in age from 27 to 59 years, with a mean of 32.5 years. All the fractures were fresh and closed fractures. According to the Letenneur's classification, 8 cases were type I, 4 cases were type II, 5 cases were type III. All the patients had no injuries of the cruciate ligament and the another part of the knee. Operative incision and fracture healing time were observed, knee joint function was evaluated by Letenneur system and HSS standard. RESULTS: The patients were followed up from 10 to 24 months with a mean of 14.6 months. All incisions achieved primary healing, and no internal fixation breakage, malunion, femoral candyle necrosis, deep vein thrombosis of lower extremity were found. Fracture healing time was from 4 to 9 months with an average of 4.7 months. According to Letenneur's functional assessment, 10 patients got an excellent results, 4 good, 3 fair. Total HSS score was 91.1 +/- 4.7 on average,15 cases obtained excellent results, 2 good. CONCLUSION: Internal fixation with lag screws and an anti-sliding plate can result in excellent effects for Hoffa fractures of the lateral femoral condyle. The key to a successful surgery is an anatomic reduction and rigid fixation of the fracture.

[Comprehensive analysis of the ischemic times of main artery injury in the limbs].

OBJECTIVE: To study the ischemic times of the main artery injury in the limbs and the influence on the limbs survival rate, and to analyze the reasons for the formation of the ischemia time. METHODS: From June 1996 to November 2012, 83 patients with completely severed limb main artery treated in our hospital were retrospectively studied. There were 77 males and 6 females, including 81 adults (ranging in age from 16 to 52 years old, with a median age of 35 years old) and 2 children (4 and 5 years old respectively). Seventy-five patients were treated with end to end anastomosis, 7 patients were treated with great saphenous vein transplantation, and 1 patient was treated with artificial blood vessel transplantation. The prior to admission ischemia time, after admission ischemia time and total ischemia time for successful and unsuccessful patients, as well as the causes of the formation of the ischemia time were studied. Limb survival rate of different ischemic time was counted. Sharpness injury or blunt injury ischemia time and amputation rate were researched statistically. All data were analyzed using SPSS statistical software. RESULTS: There were 72 limbs survived, 11 amputated. The average ischemia time was (7.45±5.94) h for limb-salvage group and (13.73±14.00) h for amputation group. Prior to admission ischemia time between amputation and limb-salvage group had no significant difference. After admission the ischemia time in amputation group was longer than limb-salvage group. The amputation rate for ischemia time 21 to 44 h group was higher than other three groups (≤ 5 h, 6 to 10 h, 11 to 20 h) (P=0.023, 0.038, 0.044). Amputation reasons can be divided into anastomosis failure in the operation, vascular thrombosis 2 to 4 days after operation and late infection. CONCLUSION: Vascular injury limbs can tolerate longer ischemia time and the limb salvage succeed. Only too long ischemia time (> 20 h), limb amputation rate increases significantly. The main cause of long time ischemia is delayed diagnosis in the hospital. Whether limb-salvage success mainly depends on the degree of trauma and the quality of the anastomosis than ischemia time.

[Clinical diagnosis and treatment of chronic osteomyelitis].

Chronic osteomyelitis is one of the most common disorder in clinic. In recent years due to diabetes, peripheral vascular disease and trauma induced disease increased, the prevalence rate increased. With the development of magnetic resonance imaging and CT imaging technology, it greatly improved the accuracy of clinical diagnosis of chronic osteomyclitis and ability to describe the infection characteristics, and provide a reliable basis for clinical treatment. The current research on chronic osteomyelitis mainly concentrated on the aspects of imaging applications and ways of using antibiotic optimization control inflammation, defect restoration and reconstruction of blood supply and treatment. But the best time to the antibiotic therapy and the use of program is still uncertain, for after debridement, bone grafting time and defect repair function of fast recovery still need further research.

[Experimental study on preventive effect of Yougui drink on femoral head necrosis in rats under micro CT].

OBJECTIVE: To explore the preventive effect of Yougui drink on femoral head necrosis in rats under micro CT. METHODS: Twenty-five SD rats were divided into steroid hormone group (group A, 10 rats ), Yougui drink group (group B,10 rats) and normal group (group C,5 rats)with random number table. Endotoxin were injected into abdominal cavity of rats in group A and B for 2 days, methylprednisolone sodium succinate were injected by gluteus for twice a week continued for 6 weeks; group B were gavaged by Yougui drink (veryday for 8 weeks; group C did not do any processing. All rats were killed on the 10th weeks,m icro CT were used to scan femoral head in vitro and preventive effect of Yougui drink (n femoral head necrosis in rats. RESULTS: There was statistical significance in BMD, BV/TV, Tb.N, Tb, Th, Thb, Sp, BS/TV and DA but no significance in SMI between group A and B. Comparison between A and C, there was significant meaning in BMD, BV/TV, Tb.N, Tb, Th, Tb, Sp, BS/TV, DA and SMI. CONCLUSION: Yougui drink on femoral head necrosis in rats under micro CT has preventive effect from BMD BV/TV, Tb.N, Tb, Th, Tb, Sp, BS/TV and DA.

[Research advance on intervertebral disc degeneration and cell death].

Intervertebral disc degeneration is considered as a primary cause of clinical low back pain, however the molecular mechanism is not clear yet. Recently, researches on the molecular basis of intervertebral disc degeneration have become a hotspot. The special structure and biomechanics properties of the disc contribute to its propensity toward degeneration. Intervertebral disc degeneration is associated with the changes of the cytological behavior,including the increase in cell death and the degradation of extracellular matrix. However, the mechanism of cell death including cell apoptosis and autophagy in intervertebral disc degeneration remains unclear. Further study on the molecular mechanism of intervertebral disc degeneration is the foundation of improving and treating the intervertebral disc degeneration in the future. Although some progresses are made in the aspect of biological study, the biological environment of intervertebral disc itself is still a challenge for the development of biological treatment. This article is to review the latest advance on the biological characteristics of normal intervertebral disc and the cell death in the process of the intervertebral disc degeneration.

[Research on regulation mechanism of osteoclast differentiation].

Osteoclasts are multinucleated giant cell, which derived from mononuclear myeloid hematopoietic stem cells with the function of bone absorption. Osteoclasts plays a key role in bone metabolism, therefore the body is very strict to regulation of osteoclastogenesis. Mobilization and differentiation of osteoclast maturation is a complex and sophisticated multi-level regulatory processes. In the relevant regulatory mechanisms, OPG/RANKL/RANK system plays a pivotal role in the process of osteoclast differentiation and maturation. Recent studies revealed that immune cells and osteoclasts were closely connect with each other in the field of bone metabolism, also provide a new therapeutic target for the treatment of bone diseases. The apoptosis of osteoclasts in bone metabolism have been payed more attention,while its mechanism is still not clear, which need further research.