Vertical transmission of infectious aerosols through building toilet drainage system: An experimental study.

The building's toilet drainage system has been identified as a potential route for the transmission of SARS-CoV-2 during outbreaks. This study employed agar-fluorescein sodium semi-solid as trace particles to investigate the possibility of vertical transmission of the SARS-CoV-2 in drainage system. In both scenarios, where floor drains were all properly sealed or dried out, simulated faeces containing fluorescein sodium were flushed into the toilet bowl. Air sampling was conducted in each restroom, and differential pressure measurements at the floor drain locations were taken. The experimental results showed that when all floor drains were properly sealed, the differential pressure at each floor drain was 0. The fluorescein sodium-traced aerosol did not transmit through the drainage system to various floors, which significantly reduced the risk of infection for users through this route. However, when all floor drains dried out, toilet users above the neutral pressure layer (NPL) were at a high risk of virus infection. Due to the increasing maximum negative pressure at the floor drain above the NPL with ascending floor levels, users on each floor above the NPL faced an elevated infection risk in restrooms. Specifically, users on the top floor were exposed to infectious aerosols roughly 1.6 times that of the first floor above the NPL. Conversely, owing to the increasing maximum positive pressure at the floor drain below the NPL with descending floor levels, users below the NPL experienced a comparatively lower infection risk. This finding has important implications for understanding the vertical transmission dynamics of SARS-CoV-2 in residential or public building and can inform the development of effective control measures.

The efficacy of ankle arthroplasty on motor function recovery in patients with orthopedic ankle injury: a systematic review and meta-analysis.

BACKGROUND: This study analyzed the effects of ankle arthroplasty on the recovery of motor function in patients with orthopedic ankle injury. METHODS: English databases including PubMed, Web of Science, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs) examining the effects of ankle arthroplasty, ankle replacement, and joint prosthesis on motor function recovery in patients with orthopedic ankle injury. The outcome indicators included the American Orthopedic Foot and Ankle Society (AOFAS) score, the 36-item short form survey (SF-36) score, the Foot and Ankle Ability Measures (FAAM) score, and the visual analog scale (VAS) score. The quality of the included literature was evaluated using the Jadad tool, and meta-analysis of the experimental data was performed using the Review Manager 5.3 software. RESULTS: A total of 7 articles, including 443 patients, were analyzed. The meta-analysis showed significant improvement in AOFAS scores among patients in the experiment group (who underwent ankle replacement) compared with those in the control group (who did not undergo ankle replacement) [mean difference (MD) =-41.89, 95% confidence interval (CI): -51.29 to 32.49, Z=8.73, P<0.00001], VAS scores (MD =5.59, 95% CI: 4.84 to 6.34, Z=14.56, P<0.00001), SF-36 scores (MD =-13.89, 95% CI: -26.74 to 1.04, Z=2.12, P=0.03), and FAAM scores (MD =-25.78, 95% CI: -31.27 to 20.29, Z=9.20, P<0.00001) compared to patients in the control group. DISCUSSION: Ankle arthroplasty had a positive effect on the quality of life, daily activities, and motor function recovery of patients with orthopedic ankle injuries. While ankle arthroplasty has potential for clinical application, future high-quality, long-term studies with larger samples and more outcome indicators are warranted to verify these results.

The GSK­3ß/ß­catenin signaling pathway is involved in HMGB1­induced chondrocyte apoptosis and cartilage matrix degradation.

Knee osteoarthritis (KOA) is a common joint disease with a high incidence rate among middle­aged and elderly individuals. However, the precise underlying pathological mechanisms and effective treatment of this disease remain to be determined. To explore the effect of high mobility group box 1 (HMGB1) on chondrocyte apoptosis and catabolism, the ATDC5 cell line was cultured as an in vitro model for cartilage research. Cultured cells were treated with recombinant HMGB1 at different concentrations. Hoechst staining and flow cytometry demonstrated that HMGB1 administration significantly induced apoptosis of ATDC5 cells, which was the same as the effect of interleukin­1ß treatment. HMGB1 also induced cartilage matrix degradation, as shown by Alcian blue staining. Moreover, HMGB1 markedly upregulated the expression levels of matrix metallopeptidases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS), while genetic silencing of HMGB1 significantly suppressed their expressions. The glycogen synthase kinase (GSK)­3ß/ß­catenin pathway was activated upon HMGB1 treatment. Pharmacological inhibitors or HMGB1 knockdown inactivated the GSK­3ß/ß­catenin pathway, inhibited the expression levels of downstream genes, including MMPs and ADAMTS, and attenuated the apoptosis of ATDC5 cells. Furthermore, the data demonstrated that HMGB1 promoted chondrocyte dysfunction via the regulation of estrogen sulfotransferase and Runt­related transcription factor 2. Thus, the findings of the present study demonstrated that HMGB1 induces chondrocyte cell apoptosis via activation of GSK­3ß/ß­catenin and the subsequent expression of multiple targeted genes.

[The effects of microenvironment on tissue-engineered osteochondral composite].

It is currently reported that extracellular matrix, biological scaffolds, conditions of stress, nutrients and metabolic waste play very important roles in tissue-engineered osteochondral composite. In this paper, we have made a review of their effects on such composite.