A deep learning model for drug screening and evaluation in bladder cancer organoids.

Three-dimensional cell tissue culture, which produces biological structures termed organoids, has rapidly promoted the progress of biological research, including basic research, drug discovery, and regenerative medicine. However, due to the lack of algorithms and software, analysis of organoid growth is labor intensive and time-consuming. Currently it requires individual measurements using software such as ImageJ, leading to low screening efficiency when used for a high throughput screen. To solve this problem, we developed a bladder cancer organoid culture system, generated microscopic images, and developed a novel automatic image segmentation model, AU2Net (Attention and Cross U2Net). Using a dataset of two hundred images from growing organoids (day1 to day 7) and organoids with or without drug treatment, our model applies deep learning technology for image segmentation. To further improve the accuracy of model prediction, a variety of methods are integrated to improve the model's specificity, including adding Grouping Cross Merge (GCM) modules at the model's jump joints to strengthen the model's feature information. After feature information acquisition, a residual attentional gate (RAG) is added to suppress unnecessary feature propagation and improve the precision of organoids segmentation by establishing rich context-dependent models for local features. Experimental results show that each optimization scheme can significantly improve model performance. The sensitivity, specificity, and F1-Score of the ACU2Net model reached 94.81%, 88.50%, and 91.54% respectively, which exceed those of U-Net, Attention U-Net, and other available network models. Together, this novel ACU2Net model can provide more accurate segmentation results from organoid images and can improve the efficiency of drug screening evaluation using organoids.

Redescription and molecular characterization of sarcocysts of Sarcocystis cymruensis from Norway rats (Rattus norvegicus) and Sarcocystis ratti from black rats (R. rattus) in China.

In the present study, sarcocysts of Sarcocystis cymruensis were found in four of 42 (9.5%) Norway rats and those of S. ratti were observed in six of 60 (10%) black rats in China. With light microscopy, the sarcocysts of the two parasites were microscopic, and had smooth, thin cyst walls (≤ 1 µm). Ultrastructurally, the sarcocysts of S. cymruensis had small, osmiophilic, bleb-like protrusions, similar to type 1c; those of S. ratti had a cyst wall with regular, short, conical protrusions, similar to type 1 g. Three loci, i.e., 18S rDNA, the mitochondrial cox1 gene (Cox1), and the mitochondrial Cytb gene (Cytb), of the two parasites were sequenced and analyzed, and the Cytb sequences of the two parasites constituted the first records of this marker in GenBank. A comparison of the newly obtained sequences of the three loci between the two parasites revealed that the interspecific similarities of 18S rDNA, Cox1, and Cytb were 96.4-97.2%, 96.5%, and 93.7%, respectively. Therefore, the two species could be better discriminated with Cytb than with 18S rDNA and Cox1. Phylogenetic analysis based on 18S rDNA sequences and Cox1 sequences indicated that the two parasites had a close relationship with Sarcocystis in nonruminant animals, especially birds and canids.

High-level soluble expression, purification, and functional characterization of the recombinant human leukemia inhibitory factor: a potential general strategy for the recombinant expression of cytokines consisting of four α-helices in a bundle.

The human leukemia inhibitory factor (hLIF) is one of the most important cytokines in the interleukin-6 (IL-6) cytokine family. Numerous studies have demonstrated that hLIF is a pleiotropic cytokine with multiple effects on different types of cells and tissues. The optimal chemical synthesis of the hLIF gene has been previously reported to increase the expression of the recombinant inclusion body protein in E. coli. However, the required refolding step limits the recovery rate. In this report, a novel strategy was designed to produce a soluble recombinant human LIF (rhLIF) in the prokaryotic system in order to obtain higher yields of the bioactive protein with simpler steps. This optimal hLIF gene was cloned, and it successfully expressed the soluble recombinant protein in E. coli using the thioredoxin (Trx) protein as a fusion partner. A simple purification procedure is established to purify the recombinant fusion protein from the soluble supernatant of the lysed culture cells. This procedure yields up to 5 mg/L rhLIF with above 95? purity. The strategy allows the protease to release target cytokines without additional N-terminus amino acids, which is an important consideration for maintaining its bioactivity. Functional analysis of the purified rhLIF by murine myeloblastic leukemia M1 cell proliferation assay demonstrates biological activity that is similar and comparable to that of hLIF. These results present a sound strategy for the soluble production of rhLIF and other homologous tertiary structure cytokines consisting of four α-helices in a bundle for basic research, as well as clinical applications.