167 research outputs found
CT Examinations for COVID-19: A Systematic Review of Protocols, Radiation Dose, and Numbers Needed to Diagnose and Predict
Purpose
Although chest CT has been discussed as a first-line test for coronavirus disease 2019 (COVID-19), little research has explored the implications of CT exposure in the population. To review chest CT protocols and radiation doses in COVID-19 publications and explore the number needed to diagnose (NND) and the number needed to predict (NNP) if CT is used as a first-line test.
Materials and Methods
We searched nine highly cited radiology journals to identify studies discussing the CT-based diagnosis of COVID-19 pneumonia. Study-level information on the CT protocol and radiation dose was collected, and the doses were compared with each national diagnostic reference level (DRL). The NND and NNP, which depends on the test positive rate (TPR), were calculated, given a CT sensitivity of 94% (95% confidence interval [CI]: 91%–96%) and specificity of 37% (95% CI: 26%–50%), and applied to the early outbreak in Wuhan, New York, and Italy.
Results
From 86 studies, the CT protocol and radiation dose were reported in 81 (94.2%) and 17 studies (19.8%), respectively. Low-dose chest CT was used more than twice as often as standard-dose chest CT (39.5% vs.18.6%), while the remaining studies (44.2%) did not provide relevant information. The radiation doses were lower than the national DRLs in 15 of the 17 studies (88.2%) that reported doses. The NND was 3.2 scans (95% CI: 2.2–6.0). The NNPs at TPRs of 50%, 25%, 10%, and 5% were 2.2, 3.6, 8.0, 15.5 scans, respectively. In Wuhan, 35418 (TPR, 58%; 95% CI: 27710–56755) to 44840 (TPR, 38%; 95% CI: 35161–68164) individuals were estimated to have undergone CT examinations to diagnose 17365 patients. During the early surge in New York and Italy, daily NNDs changed up to 5.4 and 10.9 times, respectively, within 10 weeks.
Conclusion
Low-dose CT protocols were described in less than half of COVID-19 publications, and radiation doses were frequently lacking. The number of populations involved in a first-line diagnostic CT test could vary dynamically according to daily TPR; therefore, caution is required in future planning
Line-defect-induced bending and splitting of self-collimated beams in two-dimensional photonic crystals
Cordycepin induces apoptosis of human ovarian cancer cells by inhibiting CCL5-mediated Akt/NF-κB signaling pathway
The chemokine, CCL5, is a key mediator for the recruitment of immune cells into tumors and tissues. Akt/NF-κB signaling is significantly activated by CCL5. However, the role of NF-κB inactivation in apoptosis induced by negative regulation of CCL5 remains unclear. Here, we analyzed the effect of cordycepin on NF-κB activity in SKOV-3 cells and found that cordycepin-mediated inhibition of NF-κB signaling induced apoptosis in SKOV-3 cells via the serial activation of caspases. In addition, immune-blotting analysis showed that CCL5 is highly expressed in SKOV-3 cells. In addition to activating caspases, we show that, cordycepin prevents TNF-α-induced increase in CCL5, Akt, NF-κB, and c-FLIPL activation and that CCL5 siRNA could inhibit Akt/NF-κB signaling. Moreover, cordycepin negatively regulated the TNF-α-mediated IκB/NF-κB pathway and c-FLIPL activation to promote JNK phosphorylation, resulting in caspase-3 activation and apoptosis. Also, we show that c-FLIPL is rapidly lost in NF-κB activation-deficient. siRNA mediated c-FLIP inhibition increased JNK. SP600125, a selective JNK inhibitor, downregulated p-JNK expression in cordycepin-treated SKOV-3 cells, leading to suppression of cordycepin-induced apoptosis. Thus, these results indicate that cordycepin inhibits CCL5-mediated Akt/NF-κB signaling, which upregulates caspase-3 activation in SKOV-3 cells, supporting the potential of cordycepin as a therapeutic agent for ovarian cancer
Prognostic implications of left ventricular mass-geometry in patients with no or nonobstructive coronary artery disease
Background
Coronary computed tomography angiography (CCTA) is widely used as a first-line noninvasive modality that frequently exhibits no or nonobstructive coronary artery disease (CAD) in clinical practice, along with abnormal left ventricular (LV) geometry on echocardiography. However, the combined prognostic value of these findings has not been well elucidated. Therefore, we aimed to evaluate the prognostic implications of abnormal LV geometry in individuals with no or nonobstructive CAD.
Methods
A total of 5806 subjects with no CAD or nonobstructive CAD (luminal narrowing 95 g/m2 in women and > 115 g/m2 in men, and/or relative wall thickness > 0.42. The primary outcome was all-cause mortality.
Results
A total of 5803 subjects without significant obstructive CAD (age, 56.6 ± 8.87 years; men, 3884 [66.9%]). Of them, 4045 (69.7%) subjects had normal LV geometry and 1758 (30.3%) had abnormal LV geometry respectively. During a mean follow-up of 6.2 ± 1.48 years, 84 (1.44%) subjects died in the study population. Of these, 56 subjects were from the normal LV geometry group (1.24%) and 28 were from the abnormal LV geometry group (2.32%). Subjects with abnormal LV geometry had significantly worse survival rates (log-rank, p < 0.001). After adjustment for confounding factors, abnormal LV geometry was an independent predictor of all-cause mortality (adjusted hazard ratio, 1.64; 95% confidence interval, 1.04–2.58; p = 0.034). Moreover, abnormal LV geometry was significantly worse in survival when classified as those with no CAD (log-rank, p = 0.024) and nonobstructive CAD (Log-rank, p < 0.001).
Conclusions
Abnormal LV geometry portends a worse prognosis in subjects with no or nonobstructive CAD. These findings suggest that LV geometry assessment can help improve the stratification of individuals with these CCTA findings.This work was supported by the National Research Foundation of Korea of the Ministry of Science and ICT (Grant No.2020R1C1C1010890)
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Serial Monitoring of Immune Markers Being Represented Regulatory T Cell/T Helper 17 Cell Ratio: Indicating Tolerance for Tapering Immunosuppression after Liver Transplantation
Recipients of liver transplantation (LT) require long-term immunosuppressive drug treatment, but lifelong immunosuppressive treatment has severe side effects. It is known that some LT recipients develop immune tolerance, and although the development of such operational tolerance should allow a decrease in the burden of immunosuppressive drug treatment, the factors that indicate operational tolerance are not clear. This study aimed to monitor immunological markers over time in LT recipients to identify those markers indicating the development of operational tolerance. We performed a prospective pilot study measuring immune markers, including the ratio of regulatory T (Treg) and T helper (Th) 17 cells in peripheral blood in the 14 most immunologically stable patients among 70 clinically stable LT recipients. The doses of immunosuppressive drugs given to these 14 LT recipients were tapered over time and they were monitored for immunological markers related to the development of immune tolerance. As the doses of immunosuppressive drugs were reduced, the Treg/Th17, Th1/Th17, and CD8/Th17 ratio in tolerant recipients was significantly increased compared with that of nontolerant recipients. These results suggest that monitoring of changes in the immune makers, including Treg/Th17 ratio during tapering of immunosuppression may allow prediction of the development of tolerance
Comparison of Clinical Outcomes by Different Renal Replacement Therapy in Patients with End-Stage Renal Disease Secondary to Lupus Nephritis
Comparison of Clinical Outcomes by Different Renal Replacement Therapy in Patients with End-Stage Renal Disease Secondary to Lupus Nephritis
Publication Rates for Abstracts Presented by Korean Investigators at Major Radiology Meetings
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