Forensic bone age estimation of adolescent pelvis X-rays based on two-stage convolutional neural network.

In the forensic estimation of bone age, the pelvis is important for identifying the bone age of teenagers. However, studies on this topic remain insufficient as a result of lower accuracy due to the overlapping of pelvic organs in X-ray images. Segmentation networks have been used to automate the location of key pelvic areas and minimize restrictions like doubling images of pelvic organs to increase the accuracy of estimation. This study conducted a retrospective analysis of 2164 pelvis X-ray images of Chinese Han teenagers ranging from 11 to 21 years old. Key areas of the pelvis were detected with a U-Net segmentation network, and the findings were combined with the original X-ray image for regional augmentation. Bone age estimation was conducted with the enhanced and not enhanced pelvis X-ray images by separately using three convolutional neural networks (CNNs). The root mean square errors (RMSE) of the Inception-V3, Inception-ResNet-V2, and VGG19 convolutional neural networks were 0.93 years, 1.12 years, and 1.14 years, respectively, and the mean absolute errors (MAE) of these networks were 0.67 years, 0.77 years, and 0.88 years, respectively. For comparison, a network without segmentation was employed to conduct the estimation, and it was found that the RMSE of the three CNNs above became 1.22 years, 1.25 years, and 1.63 years, respectively, and the MAE became 0.93 years, 0.96 years, and 1.23 years. Bland-Altman plots and attention maps were also generated to provide a visual comparison. The proposed segmentation network can be used to reduce the influence of restrictions like image overlapping of organs and can thus increase the accuracy of pelvic bone age estimation.

Lack of serum- and glucocorticoid-inducible kinase 3 leads to podocyte dysfunction.

Serum- and glucocorticoid-inducible kinase 3 (SGK3) is a downstream mediator of PI3K, which is essential for maintaining the functional integrity of podocytes. However, little is known about the role of SGK3 in podocyte function. Herein, we demonstrated that SGK3 contributes to the maintenance of podocyte integrity. Conditionally immortalized mouse podocyte cells (MPCs) were treated with puromycin aminonucleoside (PAN). PAN treatment inhibited the activity of SGK3 and the expression of podocin. Short hairpin RNA (shRNA)-mediated knockdown of SGK3 also reduced podocin expression in the absence of PAN. Adriamycin (ADR)-treated mice developed proteinuria and had decreased renal glomerular SGK3 expression in comparison to control mice. Consistent with a role for SGK3 in the ADR effect, SGK3 knockout (KO) mice had markedly reduced kidney podocin expression and significantly elevated proteinuria compared with wild-type mice. Electron microscopy revealed that SGK3 KO mice displayed partial effacement of podocyte foot processes. Further, a SGK3 target protein, glycogen synthase kinase-3 (GSK3), was discovered to be dramatically activated in PAN and SGK3 shRNA-treated MPCs and in SGK3 KO mice. Taken together, these data strongly suggest that SGK3 plays a significant role in regulating podocyte function, likely by controlling the expression and activity of GSK3.-Peng, L.-Q., Zhao, H., Liu, S., Yuan, Y.-P., Yuan, C.-Y., Mwamunyi, M.-J., Pearce, D., Yao, L.-J. Lack of serum- and glucocorticoid-inducible kinase 3 leads to podocyte dysfunction.

Can unstimulated whole salivary flow objectively classify salivary gland secretory function in Sjögren's syndrome?

INTRODUCTION: The aim of this study is to investigate whether the testing time for unstimulated whole salivary flow (UWSF) can be shortened to 5 min in patients with suspected Sjögren's syndrome (SjS); and which SjS patients can use UWSF to evaluate salivary gland (SG) secretory function. METHOD: A diagnostic cohort comprising suspected SjS patients was conducted to investigate the correlation between UWSF measurements taken at 10 min (UWSF_10 min) and those taken at 5 min (UWSF_5 min). A group of SjS patients was enrolled for a comparison between UWSF and stimulated whole salivary flow (SWSF). RESULTS: In 734 suspected SjS patients, there was a remarkably high concordance between UWSF_10 min and UWSF_5 min (ICC 0.970, P < 0.001; r 0.973, P < 0.001). Reducing the testing time for UWSF to 5 min resulted in a high PPV of 83.8% and an exceptionally high NPV of 98.7%. In 408 SjS patients, the cut-off values of UWSF_10 min were investigated to classify SG secretory function. Using a threshold of > 0.2 mL/min (36.8%, 150/408) instead of SWSF > 0.7 mL/min (indicating mild secretory hypofunction), the specificity and PPV were found to be 94.2% and 94.0%, respectively; and using a threshold of < 0.05 mL/min (16.9%, 69/408) instead of SWSF ≤ 0.7 mL/min (indicating moderate to severe secretory hypofunction), the specificity was remarkably high at 97.6%, accompanied by a high PPV of 91.3%. CONCLUSIONS: This study supports the possibility of reducing UWSF testing time to 5 min; and the SWSF test may be skipped for SjS patients with USWF > 0.2 mL/min, indicating mild secretory hypofunction, or < 0.05 mL/min, indicating moderate to severe secretory hypofunction. Key Points •A diagnostic cohort of 734 patients with clinical suspicion of SjS provides compelling evidence for the potential to reduce the testing time for UWSF from 10 to 5 min. •Our finding challenges the 2019 treatment recommendation for SjS, which does not require SWSF measurement in SjS patients with UWSF ≥ 0.1 mL/min. •We propose that it may be feasible to consider utilizing UWSF instead of SWSF test for objective classification of SG secretory function in over half of SjS patients.

Quercetin binds to calcineurin at a similar region to cyclosporin A and tacrolimus.

Quercetin, the primary dietary flavonol, exerts a strong inhibitory effect on calcineurin (CN), a unique Ca(2+)/calmodulin-dependent serine/threonine protein phosphatase. Using fluorescence spectroscopy (FS) we showed quercetin strongly bound to calcineurin catalytic subunit (CNA) with a ratio of 1:1; we also showed that calcineurin regulatory subunit (CNB) weakened this binding. In addition, the secondary structure of CNA was much tighter in the presence of quercetin. An FS study with CNA truncated mutant CNAa showed that the binding area for quercetin was reduced to the catalytic domain of CNA. Furthermore, fluorescence resonance energy transfer (FRET) results and molecular docking indicated three potential binding sites for quercetin, which were located at a region between the active centre of CNA and the CNB binding domain, a similar binding area to that of cyclosporin A and tacrolimus. Interestingly, this region was also important for CN substrate recognition.

The SGK3-triggered ubiquitin-proteasome degradation of podocalyxin (PC) and ezrin in podocytes was associated with the stability of the PC/ezrin complex.

Podocyte damage is commonly accompanied by destabilization of the podocalyxin (PC)/ezrin complex. Serum- and glucocorticoid-inducible kinase 3 (SGK3) plays a role in the maintenance of podocyte function, but the details of this role are poorly understood. Herein we demonstrated that SGK3 and its downstream target protein neural precursor cell expressed developmentally downregulated protein 4 subtype 2 (Nedd4-2) triggered PC and ezrin interaction. In adriamycin (ADR)-induced nephritic mice, and after puromycin aminonucleoside (PAN)-induced podocyte damage in vitro, PC and ezrin protein expression levels decreased significantly, while Nedd4-2 activity increased. Moreover, PAN treatment increased PC and ezrin ubiquitination and decreased PC/ezrin interaction in cultured mouse podocytes. The downregulation of SGK3 activity in mouse podocytes resulted in decreased PC and ezrin protein expression and increased the ubiquitin-proteasome degradation of PC and ezrin. Furthermore, upregulation of SGK3 activity mostly reversed the PAN-induced decrease in PC and ezrin protein expression. Overexpression of Nedd4-2 led to decreased ezrin protein expression via the upregulation of ezrin ubiquitination. In contrast, Nedd4-2 knockdown resulted in increased ezrin protein expression but decreased ezrin ubiquitination. In PC-transfected human embryonic kidney (HEK293T) cells, SGK3 activity downregulation and Nedd4-2 overexpression resulted in decreased PC/ezrin interaction. These results suggested that SGK3 triggers the ubiquitin-proteasome degradation of PC and ezrin, while the SGK3/Nedd4-2 signaling pathway regulates ezrin, but not PC, ubiquitination. Thus SGK3 helps to regulate podocyte function by maintaining the stability of the PC/ezrin complex.