[Study on the relationship between severe knee osteoarthritis and bone marrow edema].

OBJECTIVE: To investigate the relationship between bone marrow edema and pathological changes, symptoms and signs of severe knee osteoarthritis. METHODS: From January 2020 to March 2021, 160 patients with severe knee osteoarthritis who underwrent MRI of the knee at the Department of Bone and Joint, Wangjing Hospital, China Academy of Chinese Medical Sciences were included. Eighty patients with bone marrow edema were selected as the case group, including 12 males and 68 females, aged from 51 to 80 years old with an average of (66.58±8.10) years old, the duration of disease 5 to 40 months with an average of (15.61±9.25) months. Eighty patients without bone marrow edema were selected as the control group, including 15 males and 65 females, aged from 50 to 80 years old with an average of (67.82±8.05) years old, the duration of disease 6 to 37 months with an average of (15.75±8.18) months, BMI was (28.26±3.13) kg·m-2 ranged from 21.39 to 34.46 kg·m-2. The degree of bone marrow edema was evaluated by knee whole oragan magnetic resonance imaging score (WORMS). The degree of knee osteoarthritis was evaluated by Kellgren- Lawrence(K-L) grade and Western Ontario and McMaster University Osteoarthritis Index (WOMAC). The degree of joint pain was evaluated by visual analogue scale(VAS) and WOMAC pain score, the joint signs were evaluated by tenderness, percussion pain, joint swelling and joint range of motion. To explore the relationship between bone marrow edema and knee osteoarthritis, the prevalence of bone marrow edema and K-L grade were compared between the two groups. Furthermore the WORMS score and WOMAC index, pain-related score, and sign-related score correlation coefficient were analyzed to further explore the relationship between bone marrow edema and knee osteoarthritis index, joint pain symptoms and signs. RESULTS: There was 68.75% (55/80) of the patients in the case group were in K-L grade Ⅳ, and 52.5% (42/80) in the control group, indicating a higher proportion of patients with grade Ⅳ in the case group than the control group (χ2=4.425, P<0.05). In the case group, there was a strong correlation between bone marrow edema WORMS score and knee osteoarthritis WOMAC index. (r=0.873>0.8, P<0.001), a moderate correlation between WORMS score and VAS score and WOMAC pain score(r=0.752, 0.650>0.5, P<0.001), a moderate correlation between WORMS score and percussion pain score (r=0.784>0.5, P<0.001), and a weak correlation between WORMS score and VAS and tenderness score, joint swelling score and joint range of motion score (r=0.194, 0.259, 0.296<0.3, P<0.001). CONCLUSION: Our study suggests that severe knee osteoarthritis is associated with an increased risk of bone marrow edema. Bone marrow edema can also lead to knee osteoarthritis joint pain, with percussion pain being a positive sign, but tenderness, joint swelling and limitation of activity are not significantly related to bone marrow edema.

[Study on correlation between bone marrow edema and osteoporosis in patients with severe knee osteoarthritis].

OBJECTIVE: To explore relationship between bone marrow edema(BME) and osteoporosis in patients with severe knee osteoarthritis. METHODS: Unmatched case-control study was conducted. Totally 160 patients with severe knee osteoarthritis who had undergone knee magnetic resonance imaging (MRI) and bone mineral density examination (BMD) from January 2020 to March 2021 were included. Eighty patients complicated with BME were included in BME group, and 80 patients without BME were selected as NBME group. In BME group, there were 12 males and 68 females, aged from 51 to 80 years old with an average of(66.58±8.10) years old;the courses of disease ranged from 5 to 40 months with an average of (15.61±9.25) months;body mass index(BMI) ranged from 21.81 to 34.70 with an average of (27.79±3.00) kg·m-2;25 patients classified to grade Ⅲ and 55 patients grade Ⅳ according to Kellgren- Lawrence(K-L). In NBME group, there were 15 males and 65 females, aged from 50 to 80 years old with an average of(67.82±8.05) years old;the course of disease ranged from 6 to 37 months with an average of(15.75±8.18) months;BMI ranged from 21.39 to 34.46 with an average of (28.26±3.13) kg·m-2;25 patients were K-L Ⅲ and 55 patients with K-L Ⅳ. The degree of bone marrow edema was evaluated by knee whole oragan magnetic resonance imaging score(WORMS). Osteoporosis was diagnosed and BMD was evaluated by DXA T value. To explore the relationship between bone marrow edema and osteoporosis by comparing prevalence rate of osteoporosis between two groups, and to further explore relationship between BME and BMD by Spearman correlation analysis of BME WORMS score and DXA T value in BME group. RESULTS: The complete case data were obtained on the first diagnosis, and there was no significant difference in sex, age, courses of disease and BMI between two groups (P>0.05). The proportion of K-L Ⅳ in BME group was significantly higher than that in NBME (P<0.05). The prevalence rate of osteoporosis in BME group was significantly higher than in NBME group with the same K-L grade (P<0.001), and there was a strong negative correlation between BME WORMS score and DXA BMD T value (r=-0.812, |r|=0.812 >0.8, P<0.001). CONCLUSION: Osteoporosis is one of the risk factors of bone marrow edema in patients with severe knee osteoarthritis, and the lower the bone mineral density is, the easier it is to be complicated with bone marrow edema.

Adaptation, restoration and collapse of anammox process to La(III) stress: Performance, microbial community, metabolic function and network analysis.

During the mining of rare earth mineral, the use of lanthanum-containing fertilizers, and the disposal of lanthanum-containing electronic products, the content of lanthanum (La(III)) in typical ammonia wastewater with low carbon to nitrogen ratio is increasing day by day. Here, effects of La(III) on anammox process in performance, microbial community structure, metabolic function, and microbial co-occurrence network were investigated. The results shown that the nitrogen removal efficiency was declines briefly and then gradually recovers after low dosage (1-5 mg/L) La(III) treatment and the decrease to low level (24.25 ± 1.74%) under high La(III) dosage (10 mg/L). La(III) in the range of 1-5 mg/L significantly promoted the relative abundance of Anammoxoglobus (0.024% to 9.762%). The blocking of key metabolic pathways was confirmed to cause the breakdown of anammox by PICRUSt. Furthermore, network analysis revealed that lack of cooperation bacteria limits the activity of Anammoxoglobus.

Exploring potential impact(s) of cerium in mining wastewater on the performance of partial-nitrification process and nitrogen conversion microflora.

Cerium Ce(III) is one of the major pollutants contained in wastewater generated during Ce(III) mining. However, the effect(s) of Ce(III) on the functional genera responsible for removing nitrogen biologically from wastewater has not been studied and reported. In this study, the effects of Ce(III) on aspects of partial-nitritation-(PN) process including ammonia oxidation rate (AOR), process kinetics, and microbial activities were investigated. It was found that the effect of dosing Ce(III) in the PN system correlated strongly with the AOR. Compared to the control, batch assays dosed with 5 mg/L Ce(III) showed elevated PN efficiency of about 121%, an indication that maximum biological response was feasible upon Ce(III) dose. It was also found that, PN performance was not adversely affected, given that Ce(III) dose was ≤20 mg/L. Process kinetics investigated also suggested that the maximum Ce(III) dose without any visible inhibition to the activities of ammonium oxidizing bacteria was 1.37 mg/L, but demonstrated otherwise when Ce(III) dose exceeded 5.63 mg/L. Compared to the control, microbes conducted efficient Ce(III) removal (averaged 98.66%) via biosorption using extracellular polymeric substances (EPS). Notably, significant deposits of Ce(III) was found within the EPS produced as revealed by SEM, EDX, CLSM and FTIR. 2-dimensional correlation infrared-(2DCOS-IR) revealed ester group (uronic acid) as a major organic functional group that promoted Ce(III) removal. Excitation-emission matrix-(EEM) spectrum and 2DCOS-IR suggested the dominance of Fulvic acid, hypothesized to have promoted the performance of the PN process under Ce(III) dosage.

Effects of heavy rare earth element (yttrium) on partial-nitritation process, bacterial activity and structure of responsible microbial communities.

Yttrium (Y(III)) is mined commercially for industrial purposes due to its excellent physical properties. However, the effects of Y(III) in mining-wastewater on the performance of partial-nitritation process and ammonia-oxidizing bacteria (AOB) have not been explored. To elucidate Y(III) effects on biological mechanisms, kinetics was conducted to establish a correlation between Y(III) dosage and specific-oxygen-uptake-rate (SOUR). The mechanism(s) demonstrated by bacterial population to resist against toxic effects from Y(III) dose was also investigated using scanning electron microscopy-(SEM), energy-dispersive X-ray spectroscopy-(EDS), confocal laser scanning microscopy-(CLSM)，Fourier transform infrared-(FTIR) spectroscopy, and 2-dimensional correlation infrared-(2DCOS-IR) approach. The study revealed a strong correlation between ammonium oxidation rate (AOR) and Y(III) dosage. AOR promotion was more pronounced when Y(III) concentration was ≤20 mg/L (maximum AOR of 12.39 mgN/L/h, at 5 mg/L), whereas inhibition when Y(III) in influent was >20 mg/L (minimum AOR of 7.34 mgN/L/h, at 500 mg/L). Aiba model demonstrated high-performance (R2 = 0.962) when Y(III) concentration ranged 0-20 mg/L, whereas linear model fitted well (R2 of 0.984) to experimental data when Y(III) dose ranged 20-500 mg/L. The maximum change in SOUR (Vmax), half-rate constant (Km), and inhibition constant (Ki) reached 1.04 d-1, 20.12 mg/L, and 4.87 mg/L, respectively, an indication that dosage of Y(III) could affect the partial-nitritation process. SEM-EDS showed that the content of extracellular polymeric substances (EPS) increased along with increasing Y(III) dosage. When 20 mg/L of Y(III) was dosed, the fraction of Y(III) within the surface elemental composition of the sludge increased gradually whereas that of calcium decreased. To further comprehend the EPS production, CLSM results further revealed ß-polysaccharide as the dominant component in the EPS. FTIR/2DCOD-IR showed that the chelation of polyguluronic sections within ß-polysaccharide, together with hydrazine might be the main pathways of cell resistance, but ß- glucan, may have caused the hormesis.

High-rate partial-nitritation and efficient nitrifying bacteria enrichment/out-selection via pH-DO controls: Efficiency, kinetics, and microbial community dynamics.

Conventional nitrification/denitrification process is gradually being replaced with partial-nitritation/anammox (PN/A) processes due to its installation and running cost. However, high ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing (anammox) bacteria activity as well as optimum out-selection of nitrite-oxidizing bacteria (NOB) are necessary to achieving efficient PN/A process. Consequently, to enhance PN process via nitrifying bacteria enrichment/out-selection within psychrophilic environment, a novel pH-DO (dissolved oxygen) control strategy was proposed and the response of PN, kinetics, AOB enrichment, and NOB out-selection efficiency was investigated during start-up and long-term operation. With DO of 0.7 mg/L and pH of 7.5-7.9, quick start-up of the PN process was established within 34d as NO2--N accumulation ratio (NAR) reached 90.08 ±â€¯1.4%. Again, when NLR was elevated to 0.8 kg/m3·d (400mgNH4+-N/L), DO curtailed to 0.2 mg/L, pH maintained at 7.7 and free ammonium at 6.5 mg/L, NAR and NH4+-N removal rate could still reach 97.04 ±â€¯2.4% and 97.84 ±â€¯1.5%, respectively. After optimum control factors had been established, real nitrogen-rich-mine-wastewater was fed (DO, 0.2 mg/L, pH, 8.9, and free ammonia, 6.5 mg/L) and NAR and NH4+-N removal rate reached was 97.33 ±â€¯0.5% and 97.76 ±â€¯1.1%, respectively. Estimated kinetic parameters including maximum degradation rate (Vmax = 1.58/d), half-rate constant (Km = 33.8 mg/L), and inhibition constant (Ki = 201.6 mg/L) suggested that inhibition on NH4+-N oxidation was most feasible at higher concentration of NH4+-N. To elucidate biological mechanisms, 16S rRNA high-throughput revealed that AOB (Nitrosomonas) enrichment had increased from 0.08% to 49% whereas NOB (Nitrospira) abundance reduced from 1% to 0.034%, indicating pH-DO control efficiently enriched AOB and out-selected NOB. Conversely, when influent NH4+-N was curtailed to about 200 mg/L and free ammonia concentration maintained at 6.5 mg/L, the population of AOB was observably reduced by 6% within a period of 14 days, indicating control strategies including pH-DO control and substrate availability were the key factors which substantially influenced and promoted the activities and growth of AOBs in the present SBR.

Modeling the performance of Single-stage Nitrogen removal using Anammox and Partial nitritation (SNAP) process with backpropagation neural network and response surface methodology.

Two novel feedforward backpropagation Artificial Neural Networks (ANN)-based-models (8:NH:1 and 7:NH:1) combined with Box-Behnken design of experiments methodology was proposed and developed to model NH4+ and Total Nitrogen (TN) removal within an upflow-sludge-bed (USB) reactor treating nitrogen-rich wastewater via Single-stage Nitrogen removal using Anammox and Partial nitritation (SNAP) process. ANN were developed by optimizing network architecture parameters via response surface methodology. Based on the goodness-of-fit standards, the proposed three-layered NH4+ and TN removal ANN-based-models trained with Levenberg-Marquardt-algorithm demonstrated high-performance as computations exhibited smaller deviations-(±2.1%) as well as satisfactory coefficient of determination (R2), fractional variance-(FV), and index of agreement-(IA) ranging 0.989-0.997, 0.003-0.031 and 0.993-0.998, respectively. The computational results affirmed that the ANN architecture which was optimized with response surface methodology enhanced the efficiency of the ANN-based-models. Furthermore, the overall performance of the developed ANN-based models revealed that modeling intricate biological systems (such as SNAP) using ANN-based models with the view to improve removal efficiencies, establish process control strategies and optimize performance is highly feasible. Microbial community analysis conducted with 16S rRNA high-throughput approach revealed that Candidatus Kuenenia was the most pronounced genera which accounted for 13.11% followed by Nitrosomonas-(6.23%) and Proteocatella-(3.1%), an indication that nitrogen removal pathway within the USB was mainly via partial-nitritation/anammox process.

Accelerated start-up, long-term performance and microbial community shifts within a novel upflow porous-plated anaerobic reactor treating nitrogen-rich wastewater via ANAMMOX process.

The anaerobic ammonium oxidation (anammox) process has gained much popularity in recent years following its success in nitrogen removal. However, not much has been reported on techniques to promote anammox bacteria immobilization and associated microbial community evolution. In this study, a novel upflow porous-plate anaerobic reactor (UPPAR) was developed and explored to promote biomass (anammox) retention and growth. To comprehend the performance of the UPPAR, its nitrogen removal efficiencies, as well as the microbial community dynamics involved in the nitrogen removal process, was evaluated and reported. When NLR ranging 0.98-1.08 kg m-3 d-1 was introduced at various stages of the UPPAR operation, a rapid start-up was achieved in 63 d, and the overall nitrogen removal rate could reach 90-95%. By the end of the start-up period, it was revealed that Proteobacteria abundance had reduced by 43.92% as opposed Planctomycetes which increased from 2.95% to 43.52%. Conversely, after the UPPAR had been operated for 124 d, thus at steady-state, the most pronounced phylum observed was Planctomycetes (43.52%) followed by Proteobacteria (26.63%), Chloroflexi (5.87%), Ignavibacteriae (5.55%), and Bacteroidetes (4.9%). Predominant genera observed included Candidatus Kuenenia - (25.46%) and Candidatus Brocadia - (3.15%), an indication that nitrogen removal mechanism within the UPPAR was mainly conducted via autotrophic anammox process. Scanning electron microscopy (SEM) revealed that sludge samples obtained at steady-state were predominantly in granular form with sizes ranging between 2 mm to 5 mm. Granules surfaces were dominated with normal to coccoid-shaped cells as revealed by the SEM.

Apa is a trimeric autotransporter adhesin of Actinobacillus pleuropneumoniae responsible for autoagglutination and host cell adherence.

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia, and adherence to host cells is a key step in the pathogenic process. Although trimeric autotransporter adhesins (TAAs) were identified in many pathogenic bacteria in recent years, none in A. pleuropneumoniae have been characterized. In this study, we identified a TAA from A. pleuropneumoniae, Apa, and characterized the contribution of its amino acid residues to the adhesion process. Sequence analysis of the C-terminal amino acid residues of Apa revealed the presence of a putative translocator domain and six conserved HsfBD1-like or HsfBD2-like binding domains. Western blot analysis revealed that the 126 C-terminal amino acids of Apa could form trimeric molecules. By confocal laser scanning microscopy, one of these six domains (ApaBD3) was determined to mediate adherence to epithelial cells. Adherence assays and adherence inhibition assays using a recombinant E. coli- ApaBD3 strain which expressed ApaBD3 on the surface of E. coli confirmed that this domain was responsible for the adhesion activity. Moreover, cellular enzyme-linked immunosorbent assays demonstrated that ApaBD3 mediated high-level adherence to epithelial cell lines. Intriguingly, autoagglutination was observed with the E. coli- ApaBD3 strain, and this phenomenon was dependent upon the association of the expressed ApaBD3 with the C-terminal translocator domain.