[Revision rate of periprosthetic joint infection post total hip or knee arthroplasty of 34 hospitals in China between 2015 and 2017: a multi-center survey].

Objective: To investigate the rate of periprosthetic joint infection (PJI) revision surgeries and clinical information of hip-/knee- PJI cases nationwide from 2015 to 2017 in China. Methods: An epidemiological investigation. A self-designed questionnaire and convenience sampling were used to survey 41 regional joint replacement centers nationwide from November 2018 to December 2019 in China. The PJI was diagnosed according to the Musculoskeletal Infection Association criteria. Data of PJI patients were obtained by searching the inpatient database of each hospital. Questionnaire entries were extracted from the clinical records by specialist. Then the differences in rate of PJI revision surgery between hip- and knee- PJI revision cases were calculated and compared. Results: Total of 36 hospitals (87.8%) nationwide reported data on 99 791 hip and knee arthroplasties performed from 2015 to 2017, with 946 revisions due to PJI (0.96%). The overall hip-PJI revision rate was 0.99% (481/48 574), and it was 0.97% (135/13 963), 0.97% (153/15 730) and 1.07% (193/17 881) in of 2015, 2016, 2017, respectively. The overall knee-PJI revision rate was 0.91% (465/51 271), and it was 0.90% (131/14 650), 0.88% (155/17 693) and 0.94% (179/18 982) in 2015, 2016, 2017, respectively. Heilongjiang (2.2%, 40/1 805), Fujian (2.2%, 45/2 017), Jiangsu (2.1%, 85/3 899), Gansu (2.1%, 29/1 377), Chongqing (1.8%, 64/3 523) reported relatively high revision rates. Conclusions: The overall PJI revision rate in 34 hospitals nationwide from 2015 to 2017 is 0.96%. The hip-PJI revision rate is slightly higher than that in the knee-PJI. There are differences in revision rates among hospitals in different regions.

The involvement of senescence induced by the telomere shortness in the decline of osteogenic differentiation in BMSCs.

OBJECTIVE: BMSC (Bone marrow mesenchymal stem cells) is an important seed cell for the repair of bone and cartilage defect in the tissue engineering. The proliferation rate and differentiation capacity of BMSCs from the old donors were less than that from young donors; however, the related mechanism remained unclear. MATERIALS AND METHODS: Sprague Dawley (SD) rats BMSCs were cultured and treated. Hydrogen peroxide (H2O2) and continual passage of BMSCs were performed to induce senescence. Senescence was detected by the SA-b-Gal staining and the telomere length analysis. Cell proliferation and osteogenic differentiation were also observed. Finally, Olaparib was used to maintain the telomere length and investigate the role of telomere length and senescence on the cell proliferation and differentiation. RESULTS: H2O2 could increase the positive rate of SA-b-Gal staining in BMSCs and shorten the length of the telomere. The proliferation rate and ALP activity were also decreased by the H2O2. The senescence and decline of osteogenic differentiation could also be observed after prolonged passage of BMSCs. Inhibition of telomere length decline could attenuate the increased positive rate of SA-b-Gal staining induced by the H2O2, promote the cell proliferation, and enhance the capacity of osteogenic differentiation. CONCLUSIONS: Senescence induced by the decline of telomere length could reduce the capacity of osteogenic differentiation and inhibit cell proliferation in BMSCs.

Efficacy of 3.6% topical ALA-PDT for the treatment of severe acne vulgaris.

OBJECTIVE: To evaluate the efficacy and safety of topical 5-aminolevulinic acid (ALA) mediated photodynamic therapy (PDT) for the treatment of severe acne vulgaris. PATIENTS AND METHODS: A total of 125 patients with Pillsbury III-IV severe facial acne were treated with 3 courses of ALA-PDT with an interval of 2 weeks. ALA gel (3.6%) was applied topically to acne lesions for 1.5 h. The lesions were irradiated by a LED light of 633 nm with a light intensity of 66 mW/cm² and a light dose of 126 J/cm². Patients were evaluated for efficacy and safety at weeks 2, 4, 6, 8, 12 after the initial treatment. RESULTS: The total effective rates were 1.6%, 24.8%, 68.8%, 89.6% and 88.8% at the 2- 4- 6- 8- and 12-week after the initial treatment respectively. The clinical outcomes were the best at 4 weeks after the final treatment. The best effective rate and cure rate were 89.6% and 44% respectively. 26 patients and 16 patients showed apparent exacerbation of acne lesions before the 2nd and 3rd treatment respectively, but all of them showed good or excellent improvement after 3-course treatment. Adverse reactions were mild and transient. CONCLUSIONS: 3.6% ALA-PDT is a simple, safe and effective therapeutic option for the treatment of severe acne vulgaris.

Hemodynamic evaluation of bovine pericardial xenograft valves in the mitral position by stress Doppler echocardiography.

The function of a bovine pericardial xenograft valve in the mitral position was studied in 18 patients by using stress Doppler echocardiography after submaximal supine exercise. In 10 patients with normally functioning tissue valve, peak and mean gradients increased from 9.3 +/- 1.3 and 2.7 +/- 0.7 mmHg, respectively at rest, to 14.7 +/- 0.9 and 4.1 +/- 1.0 mmHg at peak exercise. The tissue valve area assessed by the Doppler pressure half-time method increased from 2.69 +/- 0.38 cm2 at rest, to 3.15 +/- 0.38 cm2 at peak exercise (P < 0.05). In 6 patients with mitral regurgitation, peak and mean gradients increased from 17.3 +/- 5.3 and 7.0 +/- 1.8 mmHg, respectively at rest, to 24.3 +/- 5.0 and 9.0 +/- 2.6 mmHg at peak exercise, but there was no significant change in valve area at peak exercise. Patients with severe isolated mitral regurgitation had a Vmax of more than 2 m/s and elevated pressure gradients at peak exercise. But the pressure half-time was relatively unaffected, allowing their differentiation from patients with tissue valvular stenosis. Stress Doppler echocardiography is a simple, noninvasive and reliable method for the evaluation of the mitral tissue valve function which is recommendable for patients with suspected mitral tissue valve dysfunction.

Transcoronary chemical ablation of ventricular tachycardia.

Transcoronary chemical ablation of ventricular tachycardia was recently performed in one patient with refractory ventricular tachycardia in our hospital. The procedure was successful. The arrhythmia was cured and no recurrence occurred in a 24-month period. The clinical application and mechanism of transcoronary chemical ablation were discussed.

Transcoronary ethanol ablation of experimental ventricular tachycardia after epicardial ice mapping and localizing.

Thirty-seven reproducible ventricular tachycardias (VTs) were induced in 19 dogs after the onset of myocardial infarction. The site of origin of VT was localized in 19 (59%) of 32 VTs by ice epicardial mapping. After 0.3-1.2 ml of 95% ethanol was injected into a small coronary artery supplying the arrhythmogenic area, VT was no longer inducible in 10 of 14 dogs. Intramyocardial ethanol (1-3 ml) was injected into the site of origin of VT in 9 dogs including 4 with VTs reinduced after intracoronary ethanol. Six of these VTs were not reinduced. Thus, the total efficacy rate was 84%. In 7 dogs, after injection of 0.4-1.2 ml (mean 0.5 ml) of 95% ethanol into a small normal coronary artery, the extent of the changes in ECG, CK-MB and pathology was found to be related to the size of myocardial damage and to the dose of ethanol. The smaller the dose of ethanol was given and the more distal the branch of coronary artery into which the ethanol was injected, the smaller the myocardial damage was. The data demonstrated that intracoronary or intramyocardial injection of ethanol may ablate the experimental VT induced by programmed heart stimulation in dogs after myocardial infarction, indicating that this approach may be useful and meaningful in some selected instances. However, it is necessary to limit the myocardial damage as far as possible.

Fibrinolytic activity in coronary heart disease.

To evaluate the effects of the fibrinolytic system on the development of coronary heart disease (CHD), the level of released plasminogen activator was measured by venous occlusion in 60 CHD cases, and 20 healthy subjects. The level of plasma basic plasminogen activator activity, plasminogen, fibrinogen and serum fibrin degradation products (FDP) were determined also. In comparison with control subjects, a lower level of released plasminogen activator was found in all CHD patients, being especially marked in those with unstable angina pectoris and acute myocardial infarction. The levels of plasma plasminogen, fibrinogen and FDP were also significantly changed in these patients. In acute myocardial infarction patients, the level of released plasminogen activator was lower in cases complicated with heart failure than in those without.

Dietary patterns in 10 groups and the relationship with blood pressure. Collaborative Study Group for Cardiovascular Diseases and Their Risk Factors.

An epidemiological comparative study on dietary patterns and population means of blood pressure was undertaken in 10 groups (3 of workers, 6 of farmers, 1 of fishermen) of adult males and females of northeast, north, south, middle and east China. Standardized methods and record forms were used for blood pressure measurements and 24-hr dietary recall interviews. Simple correlation and linear regression, multiple regression (adjusted for age, sex and body mass index) and ridge regression were used to analyze the relationship of dietary electrolytes and animal protein to blood pressure. The results show a significant negative association of mean daily intake of Ca and animal protein with population mean blood pressure. Excluding the fishermen's group, mean daily intake of Na showed significant positive association with both systolic and diastolic blood pressure. The Chinese diet should probably be improved, increasing Ca and animal protein and cutting salt to a much lower level.