[Periprosthetic gout flare after total knee arthroplasty: A misdiagnostic case report].

Periprosthetic gout flare is a rare arthritic condition after total knee arthroplasty, but the symptoms of gout may have often been mistaken as acute periprosthetic infection given their similarity. Misdiagnosis as periprosthetic infection can lead to unnecessary surgery, long-term dependence on anti-biotics, and even malfunction of the involved knee joint. Here, we report a case study of a patient with immunodeficiency condition of long-term oral glucocorticoid and diabetes mellitus, who had undergone a knee replacement 8 weeks before. The initial symptoms of fever and joint pain together with the dysfunction of her right knee with elevated inflammatory markers, such as increased serum leukocytes, erythrocyte sedimentation rate, C-reactive protein, and synovial cell counts led to a diagnosis of acute periprosthetic infection. Arthrocentesis and bacterial culture were performed preoperatively. According to the current Musculoskeletal Infection Society (MSIS) criteria for diagnosis of periprosthetic infection, the case was classified as periprosthetic infection and a prosthesis retained debridement surgery was performed. However we got negative culture results in all the pre-operative and intro-operative samples. The symptoms as well as the laboratory inflammatory markers improved shortly after the debridement surgery until the 11th day when all the similar systemic and local symptoms recurred. With a remedial crystal analysis of synovial fluid from the patient, gouty flare was found to be the cause of acute arthritis finally. Accor-dingly, after anti-gout medications were administrated, the symptoms associated with acute arthritis gra- dually subsided, and there was no recurrence during a 24-month follow-up. This article described the cli-nical manifestation, diagnosis and differential diagnosis, treatment of a case of periprosthetic gout. Although relatively rare, gout should be considered as a differential diagnosis in suspected periprosthetic infection. Current criteria for periprosthetic infection can not exclude the diagnosis of periprosthetic gout flare, it is therefore imperative that the analysis of joint aspirate for crystals be conducted to determine the correct course of treatment, or unnecessary surgical procedure may be performed in periprosthetic gout case.

[Hydrogen sulfide in cartilage and its inhibitory effect on matrix metalloproteinase 13 expression in chondrocytes induced by interlukin-1ß].

OBJECTIVE: To investigate whether endogenous hydrogen sulfide (H2S) was involved in the pathogenesis of osteoarthritis (OA) and its underlying mechanism, to detect H2S and its synthases expression in knee cartilage in patients diagnosed with different severity of OA, and to explore the transcription and expression of gene MMP-13 in chondrocytes treated with IL-1ß or H2S. METHODS: Synovial fluids of the in-patients with different severity of OA hospitalized in Peking University First Hospital were collected for measurement of H2S content using methylene blue assay. Articular cartilages of the patients who underwent knee arthroplasty were collected for the cell culture of relatively normal chondrocytes. The chondrocytes were cultured to the P3 generation and H2S molecular probes were used for detection of endogenous H2S generation in the chondrocytes. Immunocytochemistry was used to detect the localization of H2S synthases including cystathionine ß-synthase (CBS), cystathionine-γ-lyase (CSE), and mercaptopyruvate sulfurtransferase (MPST) in OA chondrocytes. Western blot was used to quantify the protein expressions of CSE, MPST, and CBS in cartilage tissues of the patients who were diagnosed with OA and underwent knee arthroplasty. The relatively normal human chondrocytes were cultured to passage 3 and then divided into 4 groups for different treatments: (1)the normal control group, no reagent was added; (2)the IL-1ß group, 5 µg/L of IL-1ß was added; (3)the IL-1ß+H2S group, 200 µmol/L of NaHS was added 30 min before adding 5 µg/L of IL-1ß;(4)the H2S group, 200 µmol/L of NaHS was added. The transcription and expression of gene MMP-13 in chondrocytes of each group were determined with Real-time PCR and Western blot, respectively. And the total NF-κB p65 and phosphorylated NF-κB p65 in chondrocytes were detected with Western blot. RESULTS: The content of H2S in the synovial fluid of degenerative knee was (14.3±3.3) µmol/L. Expressions of endogenous H2S and its synthases including CBS, CSE and MPST were present in the cytoplasm of chondrocytes.CSE protein expression in Grade 3 (defined by outerbridge grading) cartilage tissues was significantly increased as compared with that of Grade 1 cartilage tissues (1.67±0.09 vs. 1.26±0.11, P< 0.05). However, no significant difference of CBS or MPST expression among the different groups was observed. The expression of MMP-13 protein in the IL-1ßgroup was significantly higher than that in the normal chondrocytes (1.87±0.67 vs. 0.22±0.10, P<0.05), and that in the IL-1ß+H2S group was significantly decreased than that in the IL-1ß group (0.55±0.11 vs. 1.87±0.67, P< 0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The transcription of MMP-13 protein in the IL-1ß group was significantly higher than that in the normal chondrocytes (31.40±0.31 vs. 1.00±0.00, P<0.05), and that in the IL-1ß+H2S group was significantly decreased than that in the IL-1ß group (24.41±1.28 vs. 31.40±0.31, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The total NF-κB p65 in the IL-1ß group was significantly higher than that in the normal chondrocytes (2.13±0.08 vs. 0.73±0.08, P< 0.05), and that in the IL-1ß+H2S group was significantly decreased than that in the IL-1ß group (1.24±0.13 vs. 2.13±0.08, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group. The phosphorylated NF-κB p65 in IL-1ß group was significantly higher than that in the normal chondrocytes (1.30±0.13 vs. 0.19±0.04, P<0.05), and that in IL-1ß+H2S group was significantly decreased than that in the IL-1ß group (0.92±0.26 vs. 1.30±0.13, P<0.05), and that in the H2S group had no significant difference compared with that in the normal control group. CONCLUSION: H2S affected the cartilage degeneration by partly inhibiting the degradation of extracellular matrix.

[The microscopic observed for cells in mesocarp of part medicinal plant in Citrus L].

OBJECTIVE: To illustrate the microscopic characters of cells in mesocap of some of medicinal plants in Citrus of Rutaceae. METHOD: Microscopic observation and photograph were carried out. RESULT: It has been found that many of pavenchymatous cells are branches. It is spongy tissue that has huge room between cells. The thickening of cell wall is not obvious. The uneven thickness of walls of cells in mesocarp which is reported in the old documents are not found.