The potential role of gut microbiota outer membrane vesicles in colorectal cancer.

Colorectal cancer (CRC) is a common malignant digestive tract tumor in colorectal regions. Considerable evidence now shows that the gut microbiota have essential roles in CRC occurrence and development. Most Gram-negative bacteria release outer membrane vesicles (OMVs) via outer membrane blistering, which contain specific cargoes which interact with host cells via intercellular communications, host immune regulation, and gut microbiota homeostasis. Studies have also shown that OMVs selectively cluster near tumor cells, thus cancer treatment strategies based on OMVs have attracted considerable research attention. However, little is known about the possible impact of gut microbiota OMVs in CRC pathophysiology. Therefore, in this review, we summarize the research progress on molecular composition and function of OMV, and review the microbial dysbiosis in CRC. We then focus on the potential role of gut microbiota OMVs in CRC. Finally, we examine the clinical potential of OMVs in CRC treatment, and their main advantages and challenges in tumor therapy.

Bacterial strategies for immune systems - Role of the type VI secretion system.

The process of host infection by bacteria is complicated. Bacterial infections strongly induce the host immune system, which necessitates a robust clearance of the infection. However, bacteria have over time developed strategies that enable their evasion of attacks by the host immune system. One such strategy is the type VI secretion system (T6SS), a special needle-like secretion system that is widespread in Gram-negative bacteria and is responsible for delivering effector proteins into the external bacterial environment or directly into the host cell cytosol. Bacterial T6SS and its secreted effector proteins play an important role in the interaction between bacteria and host immune system. They also serve as antigens that are employed in the development of vaccines for clinical trials as well as future vaccine candidates. This review focuses mainly on aspects of T6SS effectors that impact the strength of the host immune system, including inflammation, autophagy, and apoptosis (silent programmed cell death). The T6SS-based vaccines are also described.

Cascaded convolutional networks for automatic cephalometric landmark detection.

Cephalometric analysis is a fundamental examination which is widely used in orthodontic diagnosis and treatment planning. Its key step is to detect the anatomical landmarks in lateral cephalograms, which is time-consuming in traditional manual way. To solve this problem, we propose a novel approach with a cascaded three-stage convolutional neural networks to predict cephalometric landmarks automatically. In the first stage, high-level features of the craniofacial structures are extracted to locate the lateral face area which helps to overcome the appearance variations. Next, we process the aligned face area to estimate the locations of all landmarks simultaneously. At the last stage, each landmark is refined through a dedicated network using high-resolution image data around the initial position to achieve more accurate result. We evaluate the proposed method on several anatomical landmark datasets and the experimental results show that our method achieved competitive performance compared with the other methods.

Serial Interval and Reproductive Number of COVID-19 Among 116 Infector-infectee Pairs - Jingzhou City, Hubei Province, China, 2020.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: The key epidemiological parameters including serial interval, basic reproductive number (R 0), and effective reproductive number (R t) are crucial for coronavirus disease 2019 (COVID-19) control and prevention. Previous studies provided different estimations but were often flawed by some limitations such as insufficient sample size and selection bias. WHAT IS ADDED BY THIS REPORT?: In this study, a total of 116 infector-infectee pairs meeting strict inclusion criteria were selected for analysis. The mean serial interval of COVID-19 was 5.81 days (standard deviation: 3.24). The estimated mean with 95% confidence interval of R 0 was 3.39 (3.07-3.75) and 2.98 (2.62-3.38) using exponential growth (EG) and maximum likelihood (ML) methods, respectively. The R t in the early phase of the epidemic was above 1 with the peak of 4.43 occurring on January 8, and then showing subsequent declines and approaching 1 on January 24. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICES?: This study supports previous findings that COVID-19 has high transmissibility and that implementing comprehensive measures is effective in controlling the COVID-19 outbreak.

Progression of cartilage degradation, bone resorption and pain in rat temporomandibular joint osteoarthritis induced by injection of iodoacetate.

BACKGROUND: Osteoarthritis (OA) is an important subtype of temporomandibular disorders. A simple and reproducible animal model that mimics the histopathologic changes, both in the cartilage and subchondral bone, and clinical symptoms of temporomandibular joint osteoarthritis (TMJOA) would help in our understanding of its process and underlying mechanism. OBJECTIVE: To explore whether injection of monosodium iodoacetate (MIA) into the upper compartment of rat TMJ could induce OA-like lesions. METHODS: Female rats were injected with varied doses of MIA into the upper compartment and observed for up to 12 weeks. Histologic, radiographic, behavioral, and molecular changes in the TMJ were evaluated by light and electron microscopy, MicroCT scanning, head withdrawal threshold test, real-time PCR, immunohistochemistry, and TUNEL assay. RESULTS: The intermediate zone of the disc loosened by 1 day post-MIA injection and thinned thereafter. Injection of an MIA dose of 0.5 mg or higher induced typical OA-like lesions in the TMJ within 4 weeks. Condylar destruction presented in a time-dependent manner, including chondrocyte apoptosis in the early stages, subsequent cartilage matrix disorganization and subchondral bone erosion, fibrosis, subchondral bone sclerosis, and osteophyte formation in the late stages. Nociceptive responses increased in the early stages, corresponding to severe synovitis. Furthermore, chondrocyte apoptosis and an imbalance between anabolism and catabolism of cartilage and subchondral bone might account for the condylar destruction. CONCLUSIONS: Multi-level data demonstrated a reliable and convenient rat model of TMJOA could be induced by MIA injection into the upper compartment. The model might facilitate TMJOA related researches.

[Expression of hsa-miR-20a in human glioma tissues and its effect on the proliferation of human glioma cells in vitro].

OBJECTIVE: To investigate miR-20a expression in human glioma and normal brain tissues and its effect on the proliferation of glioma cells in vitro. METHODS: The expression of miR-20a was detected in human normal brain tissues and glioma tissues by real-time RT-PCR. miR-20a mimics were synthesized and transfected into U251 cells via liposome, and the cell proliferation were detected using MTT assay and flow cytometry. RESULTS: The glioma tissues showed significantly up-regulated expression of miR-20a compared with normal brain tissues (P=0.035). The expression level of miR-20a was higher in high-grade than in low-grade gliomas. miR-20a mimics significantly enhanced the proliferation of U251 cells and the percentage of S-phase cells. CONCLUSION: miR-20a shows potent effect in promoting the growth of glioma cells, suggesting its important role in the pathogenesis of human glioma.