Machine Learning-Enabled Determination of Diffuseness of Brain Arteriovenous Malformations from Magnetic Resonance Angiography.

The diffuseness of brain arteriovenous malformations (bAVMs) is a significant factor in surgical outcome evaluation and hemorrhagic risk prediction. However, there are still predicaments in identifying diffuseness, such as the judging variety resulting from different experience and difficulties in quantification. The purpose of this study was to develop a machine learning (ML) model to automatically identify the diffuseness of bAVM niduses using three-dimensional (3D) time-of-flight magnetic resonance angiography (TOF-MRA) images. A total of 635 patients with bAVMs who underwent TOF-MRA imaging were enrolled. Three experienced neuroradiologists delineated the bAVM lesions and identified the diffuseness on TOF-MRA images, which were considered the ground-truth reference. The U-Net-based segmentation model was trained to segment lesion areas. Eight mainstream ML models were trained through the radiomic features of segmented lesions to identify diffuseness, based on which an integrated model was built and yielded the best performance. In the test set, the Dice score, F2 score, precision, and recall for the segmentation model were 0.80 [0.72-0.84], 0.80 [0.71-0.86], 0.84 [0.77-0.93], and 0.82 [0.69-0.89], respectively. For the diffuseness identification model, the ensemble-based model was applied with an area under the Receiver-operating characteristic curves (AUC) of 0.93 (95% CI 0.87-0.99) in the training set. The AUC, accuracy, precision, recall, and F1 score for the diffuseness identification model were 0.95, 0.90, 0.81, 0.84, and 0.83, respectively, in the test set. The ML models showed good performance in automatically detecting bAVM lesions and identifying diffuseness. The method may help to judge the diffuseness of bAVMs objectively, quantificationally, and efficiently.

Ultrasound Shear Wave Elastography for Evaluation of Diaphragm Stiffness in Patients with Stable COPD: A Pilot Trial.

OBJECTIVES: Skeletal muscle dysfunction is one of the most common comorbidities in chronic obstructive pulmonary disease (COPD). The occurrence of respiratory failure in COPD is common and leads to the patient's death. The diaphragm is the most important muscle in the respiratory system and plays a key role in the onset of respiratory failure. This study explores the feasibility of ultrasound shear wave elastography (SWE) to measure diaphragmatic stiffness and evaluates its changes in COPD patients. METHODS: In total, 77 participants (43 patients with stable COPD and 34 healthy controls) were enrolled. All subjects underwent complete diaphragmatic ultrasound SWE measurements and pulmonary function tests. The diaphragmatic stiffness was indicated via diaphragmatic shear wave velocity (SWV) at functional residual capacity (FRC). A trained operator performed the ultrasound SWE examinations of the first 15 healthy controls thrice to assess the reliability of diaphragmatic SWE. RESULTS: A good to excellent reliability was found in diaphragmatic SWV at FRC (ICC = 0.93, 95%CI 0.82-0.98). As compared to the control group, the diaphragmatic SWV at FRC was considerably high in the COPD group (median 2.5 m/s versus 2.1 m/s, P = .008). Diaphragmatic SWV at FRC was linked to forced expiratory volume in one second (r = -0.30, P = .009), forced vital capacity (r = -0.33, P = .003), modified Medical Research Council score (r = 0.30, P = .001), and COPD assessment test score (r = 0.48, P < .001). CONCLUSIONS: Ultrasound SWE may be employed as an effective tool for quantitative evaluation of diaphragm stiffness and can help in personalized management of COPD, such as treatment guidance and follow-up monitoring.

Short-term effect analysis of radiofrequency ablation combined chemotherapy on middle and late period non-small cell lung cancer.

In this study, we investigated the effect of radiofrequency ablation (RFA) combined chemotherapy on middle and late period non-small cell lung cancer (NSCLC). In total, 85 cases of middle and late period NSCLC patients were selected, and were randomly divided into the RFA combined chemotherapy group, RFA treatment group and chemotherapy group. After treatment, the three groups were followed up for computed tomography (CT) scan, and were analyzed for the effect of RFA combined chemotherapy on middle and late period NSCLC. It was found that CT value of RFA combined chemotherapy group decreased significantly compared to before surgery (P<0.05). The CT value of the RFA group decreased significantly compared to before surgery (P<0.05). The CT value of chemotherapy group was not significantly changed compared to before surgery (P>0.05). The postoperative CT value of the RFA combined chemotherapy group and RFA group was smaller compared to that of the chemotherapy group (P<0.05). Effective rate [complete response (CR) + partial response (PR)] of RFA combined chemotherapy group was significantly higher than that of the EFA and chemotherapy groups (P<0.05). Effective rate (CR+PR) of the RFA group was significantly higher than that of the chemotherapy group (P<0.05). By contrast, the progressive rate (P) of RFA combined chemotherapy group was significantly lower than that of the RFA and chemotherapy groups (P<0.05). In conclusion, RFA combined chemotherapy has obvious effect on middle and late period NSCLC, and is safe and feasible.

Tumor-derived transforming growth factor-ß is critical for tumor progression and evasion from immune surveillance.

Tumors have evolved numerous mechanisms by which they can escape from immune surveillance. One of these is to produce immunosuppressive cytokines. Transforming growth factor-ß(TGF-ß) is a pleiotropic cytokine with a crucial function in mediating immune suppression, especially in the tumor microenvironment. TGF-ß produced by T cells has been demonstrated as an important factor for suppressing antitumor immune responses, but the role of tumor-derived TGF-ß in this process is poorly understood. In this study, we demonstrated that knockdown of tumor-derived TGF-ß using shRNA resulted in dramatically reduced tumor size, slowing tumor formation, prolonging survival rate of tumor-bearing mice and inhibiting metastasis. We revealed possible underlying mechanisms as reducing the number of myeloid-derived suppressor cells (MDSC) and CD4+Foxp3+ Treg cells, and consequently enhanced IFN-γ production by CTLs. Knockdown of tumor-derived TGF-ß also significantly reduced the conversion of naive CD4+ T cells into Treg cells in vitro. Finally, we found that knockdown of TGF-ß suppressed cell migration, but did not change the proliferation and apoptosis of tumor cells in vitro. In summary, our study provided evidence that tumor-derived TGF-ß is a critical factor for tumor progression and evasion of immune surveillance, and blocking tumor-derived TGF-ß may serve as a potential therapeutic approach for cancer.

[Measuring method of spatial and spectral distribution of hollow cathode lamp].

In the present paper, the authors propose a method to measure the spatial and spectral distribution of hollow cathode lamp by imaging spectrometer. A push-broom convex grating imaging spectrometer based on Offner system is presented, with wavelength range 400-1 000 nm, field angle 22 degrees and spectral resolution 2-3 nm. The spatial distribution of Hg hollow cathode lamp was measured for the first time; this gives the spatial intensity distribution for different wavelengths and spectral distribution at different positions, with high spatial and spectral resolution. Also the hyperspectral data under different working current condition was obtained in order to analyze the differences of the distribution. It will be a powerful tool for the spatial and spectral properties measurement of hollow cathode lamps and other kinds of light sources.