CARE: A Large Scale CT Image Dataset and Clinical Applicable Benchmark Model for Rectal Cancer Segmentation

Rectal cancer segmentation of CT image plays a crucial role in timely clinical diagnosis, radiotherapy treatment, and follow-up. Although current segmentation methods have shown promise in delineating cancerous tissues, they still encounter challenges in achieving high segmentation precision. These obstacles arise from the intricate anatomical structures of the rectum and the difficulties in performing differential diagnosis of rectal cancer. Additionally, a major obstacle is the lack of a large-scale, finely annotated CT image dataset for rectal cancer segmentation. To address these issues, this work introduces a novel large scale rectal cancer CT image dataset CARE with pixel-level annotations for both normal and cancerous rectum, which serves as a valuable resource for algorithm research and clinical application development. Moreover, we propose a novel medical cancer lesion segmentation benchmark model named U-SAM. The model is specifically designed to tackle the challenges posed by the intricate anatomical structures of abdominal organs by incorporating prompt information. U-SAM contains three key components: promptable information (e.g., points) to aid in target area localization, a convolution module for capturing low-level lesion details, and skip-connections to preserve and recover spatial information during the encoding-decoding process. To evaluate the effectiveness of U-SAM, we systematically compare its performance with several popular segmentation methods on the CARE dataset. The generalization of the model is further verified on the WORD dataset. Extensive experiments demonstrate that the proposed U-SAM outperforms state-of-the-art methods on these two datasets. These experiments can serve as the baseline for future research and clinical application development.Comment: 8 page

The effect of spatio-temporal inconsistency on the subjective quality evaluation of omnidirectional videos

With the development of immersive media technologies, omnidirectional video services have been launched in many fields. Conducting subjective quality evaluation research becomes a crucial step to benchmark and ensure the quality of omnidirectional video services. As omnidirectional videos record spherical visual scenes that are broader than the visual field of human eyes, the quality scores rated by different observers are based on individual spatio-temporal viewing experience. The potential spatio-temporal inconsistency between observers may impact the reliability of subjective quality evaluation and thus challenge existing experimental methodologies. In this paper, we focus on investigating the effect of spatial-temporal inconsistency on the subjective quality evaluation of omnidirectional videos. A systematic quality evaluation experiment was designed with various viewing methods involved. Experimental results showed that the spatio-temporal inconsistency has a significant impact on the reliability of subjective quality results and the impact is strongly determined by the viewing method. We intend to provide recommendations with respect to the subjective quality evaluation of omnidirectional videos

Antimicrobial Effect of a Peptide Containing Novel Oral Spray on Streptococcus mutans

Objective. To investigate the antibacterial effect of a novel antimicrobial peptide containing oral spray GERM CLEAN on Streptococcus mutans (S. mutans) in vitro and further explore the related mechanisms at phenotypic and transcriptional levels. Methods. The disk diffusion method was used to preliminarily appraise the antimicrobial effect of GERM CLEAN. The minimal inhibitory concentration (MIC) of GREM CLEAN towards S. mutans was determined by the broth dilution method. S. mutans virulence-related phenotypic assays including initial adhesive assay, pH drop, exopolysaccharides (EPS), and biofilm formation measurements and quantitative real-time PCR (qRT-PCR) were further applied to detect the inhibitory mechanisms of GREM CLEAN at 1/2MIC. Results. The diameter (10.18 ± 1.744 mm) of inhibition zones formed by GERM CLEAN preliminarily indicated its inhibitory effect on the major cariogenic bacteria S. mutans. The minimal inhibitory concentration of GERM CLEAN on S. mutans was 100% mass fraction (the stock solution). The study of the antibacterial mechanism showed that GERM CLEAN had a certain inhibitory effect on the initial adhesion, acid production, extracellular polysaccharides (EPS) production, and biofilm formation of S. mutans. GERM CLEAN disturbed S. mutans biofilm physiology mainly through destruction of biofilm architecture and suppression of bacterial growth. The results of qRT-PCR further confirmed that the expression levels of EPS and lactic acid generation genes including gtfB, gtfC, gtfD, and ldh were significantly repressed by treating with GERM CLEAN, and this was consistent with our phenotypic results. Conclusion. The novel antimicrobial peptide containing oral spray GERM CLEAN has an anti-Streptococcus mutans effect and the inhibitory property may be due to suppression of the virulence factors of S. mutans including adhesive, acidogenicity, EPS, and biofilm formation

Engineering Antibody Reactivity for Efficient Derivatization to Generate Na_V1.7 Inhibitory GpTx‑1 Peptide–Antibody Conjugates

The voltage-gated sodium channel Na_V1.7 is a genetically validated pain target under investigation for the development of analgesics. A therapeutic with a less frequent dosing regimen would be of value for treating chronic pain; however functional Na_V1.7 targeting antibodies are not known. In this report, we describe Na_V1.7 inhibitory peptide–antibody conjugates as an alternate construct for potential prolonged channel blockade through chemical derivatization of engineered antibodies. We previously identified Na_V1.7 inhibitory peptide GpTx-1 from tarantula venom and optimized its potency and selectivity. Tethering GpTx-1 peptides to antibodies bifunctionally couples FcRn-based antibody recycling attributes to the Na_V1.7 targeting function of the peptide warhead. Herein, we conjugated a GpTx-1 peptide to specific engineered cysteines in a carrier anti-2,4-dinitrophenol monoclonal antibody using polyethylene glycol linkers. The reactivity of 13 potential cysteine conjugation sites in the antibody scaffold was tuned using a model alkylating agent. Subsequent reactions with the peptide identified cysteine locations with the highest conversion to desired conjugates, which blocked Na_V1.7 currents in whole cell electrophysiology. Variations in attachment site, linker, and peptide loading established design parameters for potency optimization. Antibody conjugation led to <i>in vivo</i> half-life extension by 130-fold relative to a nonconjugated GpTx-1 peptide and differential biodistribution to nerve fibers in wild-type but not Na_V1.7 knockout mice. This study describes the optimization and application of antibody derivatization technology to functionally inhibit Na_V1.7 in engineered and neuronal cells