Isobutyric acid promotes colorectal cancer metastasis through activating RACK1.

Colorectal cancer (CRC) metastasis plays a crucial role in disease progression, yet the regulatory mechanisms underlying metastasis remain incompletely understood. Isobutyric acid (IBA), a short-chain fatty acid found at high levels in serum of CRC patients, has been shown to be a critical metabolite influencing CRC proliferation. However, its role in tumor metastasis remains unknown. Here, utilizing liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis, we found that levels of IBA were significantly higher in patients with distant organ metastasis of CRC than in those without. Furthermore, IBA promoted CRC metastasis both in vitro and in vivo. Mass spectrometry, immunofluorescence, and cellular thermal shift assay revealed that IBA interacts with RACK1. Mechanistically, IBA binding to and activating RACK1 promotes regulation of downstream Akt and FAK signaling and CRC metastasis. Collectively, our study highlights the critical interplay between IBA and RACK1 and its impact on tumor metastasis. This study suggests that targeting the IBA-RACK1 signaling axis may be an effective therapeutic strategy for controlling CRC metastasis.

Numerical Simulation of Mass Transfer and Three-Dimensional Fabrication of Tissue-Engineered Cartilages Based on Chitosan/Gelatin Hybrid Hydrogel Scaffold in a Rotating Bioreactor.

Cartilage tissue engineering is believed to provide effective cartilage repair post-injuries or diseases. Biomedical materials play a key role in achieving successful culture and fabrication of cartilage. The physical properties of a chitosan/gelatin hybrid hydrogel scaffold make it an ideal cartilage biomimetic material. In this study, a chitosan/gelatin hybrid hydrogel was chosen to fabricate a tissue-engineered cartilage in vitro by inoculating human adipose-derived stem cells (ADSCs) at both dynamic and traditional static culture conditions. A bioreactor that provides a dynamic culture condition has received greater applications in tissue engineering due to its optimal mass transfer efficiency and its ability to simulate an equivalent physical environment compared to human body. In this study, prior to cell-scaffold fabrication experiment, mathematical simulations were confirmed with a mass transfer of glucose and TGF-ß2 both in rotating wall vessel bioreactor (RWVB) and static culture conditions in early stage of culture via computational fluid dynamic (CFD) method. To further investigate the feasibility of the mass transfer efficiency of the bioreactor, this RWVB was adopted to fabricate three-dimensional cell-hydrogel cartilage constructs in a dynamic environment. The results showed that the mass transfer efficiency of RWVB was faster in achieving a final equilibrium compared to culture in static culture conditions. ADSCs culturing in RWVB expanded three times more compared to that in static condition over 10 days. Induced cell cultivation in a dynamic RWVB showed extensive expression of extracellular matrix, while the cell distribution was found much more uniformly distributing with full infiltration of extracellular matrix inside the porous scaffold. The increased mass transfer efficiency of glucose and TGF-ß2 from RWVB promoted cellular proliferation and chondrogenic differentiation of ADSCs inside chitosan/gelatin hybrid hydrogel scaffolds. The improved mass transfer also accelerated a dynamic fabrication of cell-hydrogel constructs, providing an alternative method in tissue engineering cartilage.

Ergonomic evaluation of the operating characteristics of the 6MF-30 portable pneumatic extinguisher.

The 6MF-30 portable pneumatic extinguisher, which is one of the most widely used pieces of equipment for fighting forest fires in China, can produce great physical discomfort for the wearer. To mitigate the physical discomfort associated with the use of the 6MF-30, the operating characteristics of this machine were ergonomically evaluated. Fourteen subjects were instructed to operate the 6MF-30 portable pneumatic extinguisher using three different carrying postures (oblique strap, vertical strap and no strap) two different motions (stationary and swinging) during a simulated firefighting task. Dependent measures included heart rate (HR), electromyography (EMG) data and a subjective assessment (measured as the degree of fatigue in the left arm, right arm and waist). The EMG data were acquired from the palmaris longus and the biceps brachii of the left arm of each subject. Variance analysis indicated that the effects of the carrying posture on the HR (p < 0.001), the EMG data of the left arm (the p value of the palmaris longus is 0.001 and the p value of the biceps brachii is 0.015), and the degree of fatigue of the left and right arms (p < 0.001) were significant, while the effects of motion on all of the dependent measures, and the effects of carrying posture on the degree of fatigue of the waist were not significant. The effect of an oblique strap on the whole-body load is minimal, and the use of the equipment without a strap produced significantly greater physical discomfort for the wearer than did the oblique strap and the vertical strap. The results suggest that the strap of the 6MF-30 can help Chinese forest firefighters to lessen physical stress when operating the 6MF-30, and the use of the oblique strap should be adopted as the standard position.

[Application of folded soft palate plasty to obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To explore the effect of the modified (Uvulopalatopharyngoplasty, UPPP) where uvula is reserved completely and the soft palate is folded in the operation. METHODS: 36 patients with the obstructive sleep apnea-hypopnea syndrome (OSAHS) (30 men, 6 women) underwent operation. The uvula and the muscles of the soft palate were reserved completely, and the soft palate was folded during the operation. RESULTS: 31 patients (86.1%) reported improvement of snoring and daytime somnolence. 30 patients (83.33%) showed a decrease of at least 50% in the apnea and hypopnea indices (AHI). No velopalatal insufficiency occurred. CONCLUSION: The modified UPPP not only enlarges pharyngeal cavity, but also avoids the postoperative complications. The modified UPPP could be better than the traditional operation.