12 research outputs found
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<sub>V</sub>1.7 Inhibitory GpTx‑1 Peptide–Antibody Conjugates
The voltage-gated
sodium channel Na<sub>V</sub>1.7 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<sub>V</sub>1.7 targeting
antibodies are not known. In this report, we describe Na<sub>V</sub>1.7 inhibitory peptide–antibody conjugates as an alternate
construct for potential prolonged channel blockade through chemical
derivatization of engineered antibodies. We previously identified
Na<sub>V</sub>1.7 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<sub>V</sub>1.7 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<sub>V</sub>1.7 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<sub>V</sub>1.7 knockout mice. This study describes the
optimization and application of antibody derivatization technology
to functionally inhibit Na<sub>V</sub>1.7 in engineered and neuronal
cells