Biomechanical effect of endplate defects on the intermediate vertebral bone in consecutive two-level anterior cervical discectomy and fusion: a finite element analysis.

BACKGROUND: Intermediate vertebral collapse is a newly discovered complication of consecutive two-level anterior cervical discectomy and fusion (ACDF). There have been no analytical studies related to the effects of endplate defects on the biomechanics of the intermediate vertebral bone after ACDF. This study aimed to compare the effects of endplate defects on the intermediate vertebral bone biomechanics in the zero-profile (ZP) and cage-and-plate (CP) methods of consecutive 2-level ACDF and to determine whether collapse of the intermediate vertebra is more likely to occur using ZP. METHODS: A three-dimensional finite element (FE) model of the intact cervical spine (C2-T1) was constructed and validated. The intact FE model was then modified to build ACDF models and imitate the situation of endplate injury, establishing two groups of models (ZP, IM-ZP and CP, IM-ZP). We simulated cervical motion, such as flexion, extension, lateral bending and axial rotation, and compared the range of motion (ROM), upper and lower endplate stress, fusion fixation device stress, C5 vertebral body stress, intervertebral disc internal pressure (intradiscal pressure, or IDP) and the ROM of adjacent segments in the models. RESULTS: There was no significant difference between the IM-CP model and the CP model in the ROM of the surgical segment, upper and lower endplate stress, fusion fixation device stress, C5 vertebral body stress, IDP, or ROM of the adjacent segments. Compared with the CP model, the endplate stress of the ZP model is significantly higher in the flexion, extension, lateral bending and axial rotation conditions. Compared with the ZP model, endplate stress, screw stress, C5 vertebral stress and IDP in IM-ZP were significantly increased under flexion, extension, lateral bending and axial rotation conditions. CONCLUSIONS: Compared to consecutive 2-level ACDF using CP, collapse of the intermediate vertebra is more likely to occur using ZP due to its mechanical characteristics. Intraoperative endplate defects of the anterior lower margin of the middle vertebra are a risk factor leading to collapse of the middle vertebra after consecutive 2-level ACDF using ZP.

Micro-structure and morphology of tailings sand under different oxidation and acidification degree.

The tailings pond is a dangerous source of man-made debris flow with high potential energy. The oxidative acidification of tailings may cause the instability of the pond and induce serious safety accidents. The influence of oxidation and acidification degree on macro mechanical properties of tailings is discussed from the aspects of mineral composition and microstructure. The results show that as the degree of oxidation and acidification of tailings sand increases, the overall structural performance and load-bearing capacity decrease, and its cohesion (c) and internal friction angle (φ) show a decreasing trend. In fact, the engineering properties of tailings with different oxidation and acidification degrees are dominated by the physicochemical composition and structural characteristics. On the one hand, as the degree of oxidation increases, acidic substance will neutralize with CaCO3 and CaMg(CO3)2, resulting in the loss of cemented substance and the decrease of cementation force between tailing sand particles as well as the gradual destruction of the integrity of tailing sand. On the other hand, the increase of oxidation and acidification degree of tailing sand leads to a gradual reduction of outline (2D) fractal dimension and gray surface (3D) fractal dimension of surface laminated structure as well as the obvious reduction of laminated structure and its roughness of tailings sand.

Conversational head movement decreases close-contact exposure to expired respiratory droplets.

People constantly move their heads during conversation, as such movement is an important non-verbal mode of communication. Head movement alters the direction of people's expired air flow, therefore affecting their conversational partners' level of exposure. Nevertheless, there is a lack of understanding of the mechanism whereby head movement affects people's exposure. In this study, a dynamic meshing method in computational fluid dynamics was used to simulate the head movement of a human-shaped thermal manikin. Droplets were released during the oral expiration periods of the source manikin, during which it was either motionless, was shaking its head or was nodding its head, while the head of a face-to-face target manikin remained motionless. The results indicate that the target manikin had a high level of exposure to respiratory droplets when the source manikin was motionless, whereas the target manikin's level of exposure was significantly reduced when the source manikin was shaking or nodding its head. The source manikin had the highest level of self-exposure when it was nodding its head and the lowest level of self-exposure when its head was motionless. People's level of exposure during close contact is highly variable, highlighting the need for further investigations in more realistic conversational scenarios.

Predominance of inhalation route in short-range transmission of respiratory viruses: Investigation based on computational fluid dynamics.

During the Coronavirus disease 2019 pandemic, short-range virus transmission has been observed to have a higher risk of causing infection than long-range virus transmission. However, the roles played by the inhalation and large droplet routes cannot be distinguished in practice. A recent analytical study revealed the predominance of short-range inhalation over the large droplet spray route as causes of respiratory infections. In the current study, short-range exposure was analyzed via computational fluid dynamics (CFD) simulations using a discrete phase model. Detailed facial membranes, including eyes, nostrils, and a mouth, were considered. In CFD simulations, there is no need for a spherical approximation of the human head for estimating deposition nor the "anisokinetic aerosol sampling" approximation for estimating inhalation in the analytical model. We considered two scenarios (with two spheres [Scenario 1] and two human manikins [Scenario 2]), source-target distances of 0.2 to 2 m, and droplet diameters of 3 to 1,500 µm. The overall CFD exposure results agree well with data previously obtained from a simple analytical model. The CFD results confirm the predominance of the short-range inhalation route beyond 0.2 m for expiratory droplets smaller than 50 µm during talking and coughing. A critical droplet size of 87.5 µm was found to differentiate droplet behaviors. The number of droplets deposited on the target head exceeded those exposed to facial membranes, which implies a risk of exposure through the immediate surface route over a short range. Electronic Supplementary Material ESM: the Supplementary Materials are available in the online version of this article at 10.1007/s12273-022-0968-y.

Finite Element Analysis of Elbow Joint Stability by Different Flexion Angles of the Annular Ligament.

OBJECTIVE: The injury of the annular ligament can change the stress distribution and affect the stability of the elbow joint, but its biomechanical mechanism is unclear. The present study investigated the biomechanical effects of different flexion angles of the annular ligament on elbow joint stability. METHODS: A cartilage and ligament model was constructed using SolidWorks software according to the magnetic resonance imaging results to simulate the annular ligament during normal, loosened, and ruptured conditions at different buckling angles (0°, 30°, 60°, 90°, and 120°). The fixed muscle strengths were 40 N (F1), 20 N (F2), 20 N (F3), 20 N (F4), and 20 N (F5) for the triceps, biceps, and brachial tendons and the base of the medial collateral ligament and lateral collateral ligament. The different elbow three-dimensional (3D) finite element models were imported into ABAQUS software to calculate and analyze the load, contact area, contact stress, and stress of the medial collateral ligament of the olecranon cartilage. RESULTS: The results showed that the stress value of olecranon cartilage increased under different conditions (normal, loosened, and ruptured annular ligament) with elbow extension, and the maximum stress value of olecranon cartilage was 2.91 ± 0.24 MPa when the annular ligament was ruptured. The maximum contact area of olecranon cartilage was 254 mm2 with normal annular ligament when the elbow joint was flexed to 30°, while the maximum contact area of loosened and ruptured annular ligament was 283 and 312 mm2 at 60° of elbow flexion, and then decreased gradually. The maximum stress of the medial collateral ligament was 6.52 ± 0.23, 11.51 ± 0.78, and 18.74 ± 0.94 MPa under the different conditions, respectively. CONCLUSION: When the annular ligament ruptures, it should be reconstructed as much as possible to avoid the elevation of stress on the surface of the medial collateral ligament of the elbow and the annular cartilage, which may cause clinical symptoms.

Probable cross-corridor transmission of SARS-CoV-2 due to cross airflows and its control.

A COVID-19 outbreak occurred in May 2020 in a public housing building in Hong Kong - Luk Chuen House, located in Lek Yuen Estate. The horizontal cluster linked to the index case' flat (flat 812) remains to be explained. Computational fluid dynamics simulations were conducted to obtain the wind-pressure coefficients of each external opening on the eighth floor of the building. The data were then used in a multi-zone airflow model to estimate the airflow rate and aerosol concentration in the flats and corridors on that floor. Apart from flat 812 and corridors, the virus-laden aerosol concentrations in flats 811, 813, 815, 817 and 819 (opposite to flat 812, across the corridor) were the highest on the eighth floor. When the doors of flats 813 and 817 were opened by 20%, the hourly-averaged aerosol concentrations in these two flats were at least four times as high as those in flats 811, 815 and 819 during the index case's home hours or the suspected exposure period of secondary cases. Thus, the flats across the corridor that were immediately downstream from flat 812 were at the highest exposure risk under a prevailing easterly wind, especially when their doors or windows that connected to the corridor were open. Given that the floorplan and dimension of Luk Chuen House are similar to those of many hotels, our findings provide a probable explanation for COVID-19 outbreaks in quarantine hotels. Positive pressure and sufficient ventilation in the corridor would help to minimise such cross-corridor infections.

High attack rate in a Tong Lau house outbreak of COVID-19 with subdivided units in Hong Kong.

Poor housing conditions are known to be associated with infectious diseases such as high Coronavirus disease 2019 (COVID-19) incidences. Transmission causes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in poor housing conditions can be complex. An understanding of the exact mechanism of transmission can help to pinpoint contributing environmental issues. Here, we investigated a Hong Kong COVID-19 outbreak in early 2021 in four traditional Tong Lau houses with subdivided units. There are more than 80 subdivided units of less than 20 m2 floor area each on average. With a total of 34 confirmed COVID-19 cases, the outbreak had an attack rate of 25.4%, being one of the highest attack rates observed in Hong Kong, and ranked among the highest attack rates in reported outbreaks internationally. Tracer gas leakage and decay measurements were performed in the drainage system and in the subdivided units to determine the transport of infectious aerosols by the owner-modified sophisticated wastewater drainage pipe networks and the poor ventilation conditions in some subdivided units. The results show that the outbreak was probably due to multiple transmission routes, i.e. by the drainage pipe spread of stack aerosols, which is enhanced by poor ventilation in the subdivided units.

Spread of SARS-CoV-2 aerosols via two connected drainage stacks in a high-rise housing outbreak of COVID-19.

Vertical transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) along a vertical column of flats has been documented in several outbreaks of coronavirus disease 2019 (COVID-19) in Guangdong and Hong Kong. We describe an outbreak in Luk Chuen House, involving two vertical columns of flats associated with an unusually connected two-stack drainage system, in which nine individuals from seven households were infected. The index case resided in Flat 812 (8th floor, Unit 12), two flats (813, 817) on its opposite side reported one case each (i.e., a horizontal sub-cluster). All other flats with infected residents were vertically associated, forming a vertical sub-cluster. We injected tracer gas (SF6) into drainage stacks via toilet or balcony of Flat 812, monitored gas concentrations in roof vent, toilet, façade, and living room in four of the seven flats with infected residents and four flats with no infected residents. The measured gas concentration distributions agreed with the observed distribution of affected flats. Aerosols leaking into drainage stacks may generate the vertical sub-cluster, whereas airflow across the corridor probably caused the horizontal sub-cluster. Sequencing and phylogenetic analyses also revealed a common point-source. The findings provided additional evidence of probable roles of drainage systems in SARS-CoV-2 transmission.

Aerosol transmission of SARS-CoV-2 due to the chimney effect in two high-rise housing drainage stacks.

Stack aerosols are generated within vertical building drainage stacks during the discharge of wastewater containing feces and exhaled mucus from toilets and washbasins. Fifteen stack aerosol-related outbreaks of coronavirus disease 2019 (COVID-19) in high-rise buildings have been observed in Hong Kong and Guangzhou. Currently, we investigated two such outbreaks of COVID-19 in Hong Kong, identified the probable role of chimney effect-induced airflow in a building drainage system in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We injected tracer gas (SF6) into the drainage stacks via the water closet of the index case and monitored tracer gas concentrations in the bathrooms and along the facades of infected and non-infected flats and in roof vents. The air temperature, humidity, and pressure in vertical stacks were also monitored. The measured tracer gas distribution agreed with the observed distribution of the infected cases. Phylogenetic analysis of the SARS-CoV-2 genome sequences demonstrated clonal spread from a point source in cases along the same vertical column. The stack air pressure and temperature distributions suggested that stack aerosols can spread to indoors through pipe leaks which provide direct evidence for the long-range aerosol transmission of SARS-CoV-2 through drainage pipes via the chimney effect.

Extended short-range airborne transmission of respiratory infections.

Debate and scientific inquiries regarding airborne transmission of respiratory infections such as COVID-19 and influenza continue. Health authorities including the WHO and the US CDC have recognized the airborne transmission of COVID-19 in specific settings, although the ventilation requirements remain to be determined. In this work we consider the long-range airborne transmission as an extended short-range airborne route, which reconciles the link between short- and long-range airborne routes. The effective short-range distance is defined as the distance in short range at which long-range route has the same volumetric exposure value as that due to short-range route. Our data show that a decrease in ventilation rate or room volume per person, or an increase in the ratio of the number of infected to susceptible people reduces the effective short-range distance. In a normal breathing scenario with one out of five people infected and a room volume of 12 m3 per person to ensure an effective short-range distance of 1.5 m, a ventilation rate of 10 L/s per person is needed for a duration of 2 h. Our results suggest that effective environmental prevention strategies for respiratory infections require appropriate increases in the ventilation rate while maintaining a sufficiently low occupancy. PRACTICAL IMPLICATIONS: Demonstration of the long-range airborne route as an extended short-range airborne route suggests the significant role played by building ventilation in respiratory infection exposure. The reconciliation of short- and long-range airborne transmission suggests that the commonly observed dominance of close-contact transmission is a probable evidence of short-range airborne transmission, following a separate earlier study that revealed the relative insignificance of large droplet transmission in comparison with the short-range airborne-route. Existing ventilation standards do not account for respiratory infection control, and this study presents a possible approach to account for infection under new ventilation standards.

Evidence for lack of transmission by close contact and surface touch in a restaurant outbreak of COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is primarily a respiratory disease that has become a global pandemic. Close contact plays an important role in infection spread, while fomite may also be a possible transmission route. Research during the COVID-19 pandemic has identified long-range airborne transmission as one of the important transmission routes although lack solid evidence. METHODS: We examined video data related to a restaurant associated COVID-19 outbreak in Guangzhou. We observed more than 40,000 surface touches and 13,000 episodes of close contacts in the restaurant during the entire lunch duration. These data allowed us to analyse infection risk via both the fomite and close contact routes. RESULTS: There is no significant correlation between the infection risk via both fomite and close contact routes among those who were not family members of the index case. We can thus rule out virus transmission via fomite contact and interpersonal close contact routes in the Guangzhou restaurant outbreak. The absence of a fomite route agrees with the COVID-19 literature. CONCLUSIONS: These results provide indirect evidence for the long-range airborne route dominating SARS-CoV-2 transmission in the restaurant. We note that the restaurant was poorly ventilated, allowing for increasing airborne SARS-CoV-2 concentration.

iTRAQ-based proteomic analysis of the molecular mechanisms and downstream effects of fatty acid synthase in osteosarcoma cells.

BACKGROUND: Fatty acid synthase (FASN) is a lipogenic enzyme that participates in tumor progression. We previously showed that FASN is dysregulated in OS malignancy, but the molecular mechanism(s) of these effects remained unclear. METHODS: We examined differentially expressed proteins (DEPs) in FASN-silenced osteosarcoma 143B cells and their parental cells by isobaric tags for relative and absolute quantitation (iTRAQ). Differentially expressed proteins were classified using GO and KEGG analysis. The association between FASN and heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) was confirmed using qPCR, Western blot, and immunohistochemistry. The function of HNRNPA1 in osteosarcoma was determined using CCK-8, colony formation, wound healing, transwell migration, and invasion assays. RESULTS: Among the 4971 identified proteins, 567 DEPs (325 upregulated and 242 downregulated) were identified. The top 10 upregulated proteins comprised HIST1H2AB, INA, INTS5, MTCH2, EIF1, MAPK1IP1L, PXK, RPS27, PM20D2, and ZNF800, while the top 10 downregulated proteins comprised NDRG1, CNTLN, STON2, GDF7, HECTD3, HBB, TPM1, PPP4R4, PTTG1IP, and PLCB3. Bioinformatic analysis indicated that the DEPs were related to cellular processes, metabolic processes, biological regulation, binding, and catalytic activity. HNRNPA1 was dysregulated in FASN-silenced 143B and HOS cells. qPCR, Western blot, and immunohistochemistry showed that FASN expression positively correlates with HNRNPA1 expression. Further studies indicated that HNRNPA1 correlates with OS diagnosis and prognosis. And HNRNPA1 silence inhibits the proliferation, migration, and invasion in OS cells. CONCLUSION: HNRNPA1 acts as targets downstream of FASN and potential biomarker and oncogene in OS.

Transparent floatable magnetic alginate sphere used as photocatalysts carrier for improving photocatalytic efficiency and recycling convenience.

Practical application of powder photocatalysts is far from satisfying due to their low photon utilization, inconvenient recovery and potential environmental risk. In this study, an easily recoverable, environmentally friendly and highly transparent floatable magnetic photocatalyst carrier was prepared based on biopolymer alginate and Fe3O4 particles. Further, three different types of photocatalysts were chosen as model semiconductor photocatalysts and loaded on the shell of the carriers. The freeze process facilitated the formation of internal cavities that enhanced floating ability and transparency of the spheres. Meanwhile, the excellent floating performance offered massive reaction sites for pollutants reacting with photocatalysts, O2 and photons on the air/water interface. Photodegradation results showed all three floatable hybrid photocatalysts exhibited enhanced photocatalytic efficiencies compared to the virgin photocatalysts. In short, the carrier can integrate excellent floating ability, environmental friendliness and full recycling with good stability, and it can greatly improve the photocatalytic efficiency of various powder semiconductor photocatalysts.

Long-term antibacterial composite via alginate aerogel sustained release of antibiotics and Cu used for bone tissue bacteria infection.

Bone related-bacterial diseases including wound infections and osteomyelitis (OM) remain a serious problem accompanied with amputation in most severe cases. In this work, we report an exceptional effective antibacterial alginate aerogel, which consists of tigecycline (TGC) and octahedral Cu crystal as an organo-inorganic synergy platform for antibacterial and local infection therapy applications. The alginate aerogel could greatly prolong the release of copper ions and maintain effective antibacterial concentration over 18 days. The result of in-vitro experiments demonstrated that the alginate aerogel has an exceptional effective function on antibacterial activity. Cytotoxicity tests indicated that the alginate aerogel has low biological toxicity (average cell viability >75%). These remarkable results suggested that the alginate aerogel exhibits great potential for the treatment of OM, and has a prosperous future of application in bone tissue engineering.

Impact of intervention methods on COVID-19 transmission in Shenzhen.

By March 31, 2020, COVID-19 had spread to more than 200 countries. Over 750,000 confirmed cases were reported, leading to more than 36,000 deaths. In this study, we analysed the efficiency of various intervention strategies to prevent infection by the virus, SARS-CoV-2, using an agent-based SEIIR model, in the fully urbanised city of Shenzhen, Guangdong Province, China. Shortening the duration from symptom onset to hospital admission, quarantining recent arrivals from Hubei Province, and letting symptomatic individuals stay at home were found to be the three most important interventions to reduce the risk of infection in Shenzhen. The ideal time window for a mandatory quarantine of arrivals from Hubei Province was between 10 January and January 17, 2020, while the ideal time window for local intervention strategies was between 15 and 22 January. The risk of infection could have been reduced by 50% if all symptomatic individuals had immediately gone to hospital for isolation, and by 35% if a 14-day quarantine for arrivals from Hubei Province had been introduced one week earlier. Intervention strategies implemented in Shenzhen were effective, and the spread of infection would be controlled even if the initial basic reproduction number had doubled. Our results may be useful for other cities when choosing their intervention strategies to prevent outbreaks of COVID-19.

Aurora-B Promotes Osteosarcoma Cell Growth and Metastasis Through Activation of the NPM1/ERK/NF-κß/MMPs Axis.

PURPOSE: Osteosarcoma (OS) is the most common primary malignant tumor of the bone in young adolescents and children. We explored the underlying mechanism of Aurora-B in promoting OS cell proliferation and metastasis. PATIENT AND METHODS: Bioinformatics was employed to predict the substrate of Aurora-B. IHC and Western blot were used to confirm the correlation between Aurora-B and NPM1. ERK/NF-κß pathway-related proteins were detected by Western blot and immunofluorescence (IF). CCK8, wound healing, transwell, and Tunel assays were used to identify the cell proliferation, migration and apoptosis potential. Spontaneous metastasis xenografts were established to confirm the role of Aurora-B and NPM1. RESULTS: Aurora-B promotes NPM1 phosphorylation on Ser125. The phosphorylation of NPM1Ser125 induced by Aurora-B activates the ERK/NF-κß signaling. Further study revealed that Aurora-B promotes proliferation, migration and inhibits apoptosis via phosphorylating NPM1 in vitro and in vivo. CONCLUSION: Aurora-B promotes OS malignancy via phosphorylating NPM1Ser125 and activating ERK/NF-κß signaling.

Close contact behavior in indoor environment and transmission of respiratory infection.

Close contact was first identified as the primary route of transmission for most respiratory infections in the early 20th century. In this review, we synthesize the existing understanding of the mechanisms of close contact transmission. We focus on two issues: the mechanism of transmission in close contact, namely the transmission of the expired particles between two people, and the physical parameters of close contact that affect the exposure of particles from one individual to another, or how the nature of close contact plays a role in transmission. We propose the existence of three sub-routes of transmission: short-range airborne, large droplets, and immediate body-surface contact. We also distinguish a "body contact," which is defined with an interpersonal distance of zero, from a close contact. We demonstrate herein that the short-range airborne sub-route may be most common. The timescales over which data should be collected to assess the transmission risk during close contact events are much shorter than those required for the distant airborne or fomite routes. The current paucity of high-resolution data over short distances and timescales makes it very difficult to assess the risk of infection in these circumstances.

Long noncoding RNA PCAT-1 acts as an oncogene in osteosarcoma by reducing p21 levels.

Long non-coding RNA (lncRNA) is emerging as a critical regulator in multiple cancers. Recently, lncRNA PCAT-1 was found to be up-regulated in prostate cancer and hepatocellular carcinoma, exerting oncogenic effects. However, the biological function and regulatory mechanism of PCAT-1 remain unclear in osteosarcoma (OS). In this study, we reported that PCAT-1 expression was also upregulated in OS tissues, and its overexpression was remarkably associated with tumor size, Enneking stage, tumor node metastasis (TNM) stage and metastasis in patients with OS. Knockdown of PCAT-1 suppressed OS cells proliferation, migration and invasion in vitro, and inhibited the tumorigenicity of OS cells in vivo. Mechanistic investigations revealed that PCAT-1 could interact with EZH2, thereby repressing p21 expression. Additionally, rescue experiments indicated that PCAT-1 functioned as an oncogene partly via suppressing p21 in OS cells. Collectively, our findings demonstrate that PCAT-1 is a new candidate for use in OS diagnosis, prognosis and therapy.

Potential Molecular Mechanisms of AURKB in the Oncogenesis and Progression of Osteosarcoma Cells: A Label-Free Quantitative Proteomics Analysis.

Our previous study indicated that knockdown of Aurora-B inhibit the proliferation of osteosarcoma cells. But the function and molecular mechanisms of Aurora-B in osteosarcoma cells growth and metastasis remains unclear. The aim of this study was to investigate the molecular mechanisms of Aurora-B in the progression of osteosarcoma. Osteosarcoma cells (U2-OS and 143B) were treated with specific Lentivirus-Vectors (up or downregulation Aurora-B). The ability of cells proliferation, migration, and invasion was measured using Cell-Counting Kit-8, wound healing and transwell invasion assays. Furthermore, based on label-free quantitative proteomic analysis of potential molecular mechanisms of Aurora-B in human 143B cells. A total of 25 downregulated and 76 upregulated differentially expressed proteins were screened in terms of the change in their expression abundance. We performed functional annotation and functional enrichment analyses. Gene ontology enrichment, KEGG analysis, and protein-protein interaction networks were constructed and analyzed. We found that the PTK2 may play an important role in the progression of osteosarcoma cells. Finally, Western blot revealed that expression of PTK2, AKT, PI3K, and nuclear factor-kappaB increased after over expression of Aurora-B. Overall, these data highlight that Aurora-B may promote the malignant phenotype of osteosarcoma cells by activating the PTK2/PI3K/AKt/nuclear factor-KappaB pathway.

Risk factors for bone metastasis from renal cell cancer.

OBJECTIVE: The prognosis for renal cell carcinoma (RCC) is related to a high rate of metastasis, including 30% of bone metastasis. In this study, we investigate the correlation between diverse clinical factors and bone metastases secondary from renal cell cancer (RCC), and to identify potential risk factors for bone metastasis in newly diagnosed patients and those who have already received treatment. METHODS: The clinical data of 372 patients with RCC were reviewed from January 2000 to August 2016. The correlations between age, gender, histopathologic types, alkaline phosphotase (ALP), CEA, AFP, CA-125, CA-153, CA-199, calcium, hemoglobin (HB) and bone metastases were analyzed. And the risk factors for bone metastases in RCC were identified by multivariate logistic regression analysis. The cutoff value, sensitivity and specificity of the independent correlation factors were calculated by receiver operating characteristic (ROC) curve. RESULTS: The bone is the second to the lung as a distant metastasis target site in patients with RCC. Thirty eight individuals were identified with bone metastases. Of these patients, significantly higher levels of ALP, calcium, HB were found than those without bone metastasis (P < 0.05, respectively). No significant differences were detected in CEA, AFP, CA-125, CA-153, CA-199, age, gender and histopathologic types between patients with and without bone metastases (P > 0.05, respectively). Multivariate logistic regression analysis indicated that ALP, calcium and HB were independent risk factors correlated with bone metastasis (P < 0.05, respectively). ROC curves demonstrated these factors had comparable accuracy at predicting bone metastasis (AUC were 0.749, 0.633 and 0.665, respectively). The cutoff values of ALP, calcium and HB were 105.5 U/L, 2.615 mmol/L and 111.5 g/L, respectively. The sensitivities of them were 57.9%, 36.8% and 71.1% for predicting bone metastasis, with specificities of 83.5%, 95.2% and 65.3%, respectively. CONCLUSION: Based on our study, the concentrations of ALP, calcium and HB were potentially risk factors for bone metastasis in patients with RCC. For newly diagnosed patients, if the values of ALP>105.5 U/L, calcium>2.615 mmol/L and HB<111.5 g/L were detected, intensive monitoring and bone scanning are warranted for them.