Automated Prediction of Proximal Middle Cerebral Artery Occlusions in Noncontrast Brain Computed Tomography.

BACKGROUND: Early identification of large vessel occlusion (LVO) in patients with ischemic stroke is crucial for timely interventions. We propose a machine learning-based algorithm (JLK-CTL) that uses handcrafted features from noncontrast computed tomography to predict LVO. METHODS: We included patients with ischemic stroke who underwent concurrent noncontrast computed tomography and computed tomography angiography in seven hospitals. Patients from 5 of these hospitals, admitted between May 2011 and March 2015, were randomly divided into training and internal validation (9:1 ratio). Those from the remaining 2 hospitals, admitted between March 2021 and September 2021, were designated for external validation. From each noncontrast computed tomography scan, we extracted differences in volume, tissue density, and Hounsfield unit distribution between bihemispheric regions (striatocapsular, insula, M1-M3, and M4-M6, modified from the Alberta Stroke Program Early Computed Tomography Score). A deep learning algorithm was used to incorporate clot signs as an additional feature. Machine learning models, including ExtraTrees, random forest, extreme gradient boosting, support vector machine, and multilayer perceptron, as well as a deep learning model, were trained and evaluated. Additionally, we assessed the models' performance after incorporating the National Institutes of Health Stroke Scale scores as an additional feature. RESULTS: Among 2919 patients, 83 were excluded. Across the training (n=2463), internal validation (n=275), and external validation (n=95) datasets, the mean ages were 68.5±12.4, 67.6±13.8, and 67.9±13.6 years, respectively. The proportions of men were 57%, 53%, and 59%, with LVO prevalences of 17.0%, 16.4%, and 26.3%, respectively. In the external validation, the ExtraTrees model achieved a robust area under the curve of 0.888 (95% CI, 0.850-0.925), with a sensitivity of 80.1% (95% CI, 72.0-88.1) and a specificity of 88.6% (95% CI, 84.7-92.5). Adding the National Institutes of Health Stroke Scale score to the ExtraTrees model increased sensitivity (from 80.1% to 92.1%) while maintaining specificity. CONCLUSIONS: Our algorithm provides reliable predictions of LVO using noncontrast computed tomography. By enabling early LVO identification, our algorithm has the potential to expedite the stroke workflow.

Estrogenic activity produced by aqueous extracts of silkworm (Bombyx mori) pupae in ovariectomized rats.

This study examined the estrogenic activity produced by aqueous extracts of silkworm (Bombyx mori) pupae in ovariectomized (OVX) rats. The components of silkworm pupae were extracted in distilled water at room temperature for 6 hours. The ovaries of six-week old female rats were then bilaterally removed. One week after OVX, the animals were treated with 200, 400 or 600 mg/kg/day of silkworm pupae extracts. The body weights of the OVX rats increased remarkably compared to the control rats, however their relative uterus weights to body weights decreased significantly. Treatment with the aqueous extracts of silkworm pupae dramatically improved the decreased uterus weights of OVX rats, with the highest increase observed in treatment with 200 mg/kg/day of the aqueous extracts. Additionally, treatment with aqueous extracts (200 mg/kg/day) of silkworm pupae significantly elevated the serum 17beta-estradiol contents of OVX rats when compared to the control animals. To examine the toxic effects of silkworm pupae on the hepatic functions of OVX rats, the levels of serum glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) were measured. The serum GOT and GPT levels did not change in response to the administration of aqueous extracts (200, 400 and 600 mg/kg/day) for 4-weeks. Taken together, these results suggest that the aqueous extracts of silkworm pupae may have estrogenic activity, which suggests that silkworm pupae may be useful in the prevention and/or treatment of menopausal disorders caused by deficiencies in female sexual hormones, including estrogen.

Effects of gangliosides on the differentiation of human mesenchymal stem cells into osteoblasts by modulating epidermal growth factor receptors.

Gangliosides are sialic acid-conjugated glycosphingolipids that are believed to regulate cell differentiation as well as the signals of several signal molecules, including epidermal growth factor receptors (EGFR). These compounds are localized in a glycosphingolipid-enriched microdomain on the cell surface and regulated by the glycosphingolipid composition. However, the role that gangliosides play in osteoblastogenesis is not yet clearly understood, therefore, in this study, the relationship between gangliosides and EGFR activation was investigated during osteoblast differentiation in human mesenchymal stem cells (hMSCs). The results of high-performance thin-layer chromatography (HPTLC) showed that ganglioside GM3 expression was decreased, whereas ganglioside GD1a expression was increased during the differentiation of hMSCs into osteoblasts. In addition, an increase in the activation of alkaline phosphatase (ALP) was observed in response to treatment with EGF (5 ng/ml) and GD1a (1 microM) (p<0.05). The activation of ALP was significantly elevated in response to treatment of ganglioside GD1a with EGF when compared to control cells (p<0.01). However, treatment with GM3 (1muM) resulted in decreased ALP activation (p<0.01), and treatment of hMSCs with a chemical inhibitor of EGFR, AG1478, removed the differential effect of the two gangliosides. Moreover, incubation of the differentiating cells with GD1a enhanced the phosphorylation of EGFR, whereas treatment with GM3 reduced the EGFR phosphorylation. However, AG1478 treatment inhibited the effect of ganglioside GD1a elicitation on EGFR phosphorylation. Taken together, these results indicate that GD1a promotes osteoblast differentiation through the enhancement of EGFR phosphorylation, but that GM3 inhibits osteoblast differentiation through reduced EGFR phosphorylation, suggesting that GM3 and GD1a are essential molecules for regulating osteoblast differentiation in hMSCs.

Expression of ganglioside GT1b in mouse embryos at different developmental stages after cryopreservation.

Gangliosides are a family of sialic acid-containing glycosphingolipids that are abundant in neurons and have a variety of functions in developing and mature tissues. We examined the expression of ganglioside GT1b in the embryonic preimplantation stage after freezing and thawing processes to determine the regulatory roles of ganglioside GT1b in early embryonic development. ICR mouse embryos at the two-cell stage obtained by flushing the oviducts were frozen by two cryopreservation procedures, slow freezing using a programmable freezer or vitrification by direct plunging into liquid nitrogen. Slow freezing was conducted with equilibration in 1.5 M 1,2-propanediol or 5% equilibration glycerol. Vitrification was applied with a 10-15 min equilibration in 7.5% ethylene glycol (EG), 7.5% dimethylsulfoxide (DMSO), and 30 sec in a solution of 15% EG, 15% DMSO and 0.5 M sucrose. Immediately after thawing, the survival rate of the embryos was assessed by their morphology and ability to develop to blastocysts in culture. The survival rate of vitrified and thawed embryos (92%) was significantly higher than that of slow frozen and thawed embryos (76%) (P<0.05). A tendency of higher blastocyst rate was found in the vitrified and thawed embryos compared to that of the slow frozen and thawed embryos. Confocal immunofluorescence staining confirmed that surviving embryos expressed ganglioside GT1b, with the strongest expression at the compacted eight-cell or later stage embryos. Ganglioside GT1b was not observed in the TUNEL-positive, apoptotic embryos, suggesting that cryopreservation had induced DNA breaks in them. These results suggest that ganglioside GT1b may play an important role in embryo survival or development.

Effects of daunorubicin on ganglioside expression and neuronal differentiation of mouse embryonic stem cells.

Gangliosides are implicated in neuronal development processes. The regulation of ganglioside levels is closely related to the induction of neuronal cell differentiation. In this study, the relationship between ganglioside expression and neuronal cell development was investigated using an in vitro model of neural differentiation from mouse embryonic stem (mES) cells. Daunorubicin (DNR) was applied to induce the expression of gangliosides in embryoid body (EB) (4+). We observed an increase in expression of gangliosides in all stages of EBs by treatment of DNR (2microM). High-performance thin-layer chromatography (HPTLC) showed that gangliosides GD3, GD1a, GT1b, and GQ1b increased in DNR-treated 7-day-old EB (4+) [EB (4+):7]. DNR treatment significantly increased the expression of gangliosides, especially GT1b and GQ1b in comparison to control cells. Interestingly, GQ1b co-localized with microtubule-associated protein 2 (MAP-2) expressing cells in DNR-treated EB (4+):7. The co-localization of GQ1b and MAP-2 was found in neurite-bearing cells in DNR-treated 15-day-old EB (4+) [EB (4+):15], whereas no significant expression of GQ1b and less neurite formation were observed in untreated control. Also, the expression of synaptophysin and NF200, both neuronal markers associated with neruites, was increased by DNR treatment. These results demonstrate that DNR increases expression of gangliosides, especially GQ1b, in differentiating neuronal cells. Further, neurite-bearing neuronal cell differentiation can be facilitated by DNR, possibly through the induction of gangliosides. Thus, the present data suggest that DNR is beneficial for facilitating neuronal differentiation from ES cells and among the gangliosides analyzed in the present study, GQ1b is mainly involved in neurite formation.