Complex network-based classification of radiographic images for COVID-19 diagnosis.

In this work, we present a network-based technique for chest X-ray image classification to help the diagnosis and prognosis of patients with COVID-19. From visual inspection, we perceive that healthy and COVID-19 chest radiographic images present different levels of geometric complexity. Therefore, we apply fractal dimension and quadtree as feature extractors to characterize such differences. Moreover, real-world datasets often present complex patterns, which are hardly handled by only the physical features of the data (such as similarity, distance, or distribution). This issue is addressed by complex networks, which are suitable tools for characterizing data patterns and capturing spatial, topological, and functional relationships in data. Specifically, we propose a new approach combining complexity measures and complex networks to provide a modified high-level classification technique to be applied to COVID-19 chest radiographic image classification. The computational results on the Kaggle COVID-19 Radiography Database show that the proposed method can obtain high classification accuracy on X-ray images, being competitive with state-of-the-art classification techniques. Lastly, a set of network measures is evaluated according to their potential in distinguishing the network classes, which resulted in the choice of communicability measure. We expect that the present work will make significant contributions to machine learning at the semantic level and to combat COVID-19.

LPS-aggravated Ferroptosis via Disrupting Circadian Rhythm by Bmal1/AKT/p53 in Sepsis-Induced Myocardial Injury.

Circadian disruption is involved in the progress of sepsis-induced cardiomyopathy (SICM), one of the leading causes of death in sepsis. The molecular mechanism remains ambiguous. In this study, LPS was used to build SICM model in H9c2 cell. The results suggested that LPS induced cytotoxicity via increasing ferroptosis over the time of course. After screening the expressions of six circadian genes, the circadian swing of Bmal1 was dramatically restrained by LPS in H9c2 cell of SIMC vitro model. PcDNA and siRNA were used to upregulate and downregulate Bmal1 and confirmed that Bmal1 inhibited LPS-triggered ferroptosis in H9c2 cells. Then, the results suggested that AKT/p53 pathway was restrained by LPS in H9c2 cell. Rescue test indicated that Bmal1 inhibited LPS-triggered ferroptosis via AKT/p53 pathway in H9c2 cells. In summary, our findings demonstrated that LPS induced cytotoxicity via increasing ferroptosis over the time of course in H9c2 cells and Bmal1 inhibited this toxicity of LPS via AKT/p53 pathway. Although further studies are needed, our findings may contribute to a new insight to mechanism of SICM.

[Evaluation on the safety and efficacy of lyophilized purified human rabies vaccine (CTN-Vero-RV)].

OBJECTIVE: To observe the safety and efficacy of lyophilized purified human rabies vaccine CTN-Vero RV, CTN strain produced in Vero cells. METHODS: 450 healthy volunteers were divided into two groups, with 300 of them receiving CTN-Vero-RV (rabies vaccine for human use made in Vero cells with CTN strain) while 150 of them receiving PVRV to serve as control group. All the subjects were immunized on days 0, 3, 7, 14 and 28 at deltoid muscle respectively. Local and systemic reactions were observed and sera were collected for neutralizing antibody testing using RFFIT. 365 and 730 days after the first dose, sera from the 212 and 176 subjects of the studied group while 97 and 80 subjects from the control group were collected to test for neutralizing antibody. RESULTS: No severe local or systemic reactions were observed after immunization was performed in the two groups. On days 3, 7, 14, 28 and 365 after the first dose, the antibody positive rates appeared to be 2.35%, 80.78%, 100.00%, 100.00%, 98.58% and 73.30% in the study group and 4.00%, 87.20%, 100.00%, 100.00%, 97.94% and 76.25% in the controls respectively. On day 0, 3, 7, 14, 28, 365 and 730, GMT of the neutralizing antibody level were 0.12, 1.01, 9.83, 12.61, 3.68 and 2.81 IU/ml in the study group while 0.13, 1.18, 10.24, 11.61, 4.18 and 1.92 IU/ml were seen in the control group respectively. There were no significant differences in both antibody positive rates and GMT between the two groups on days 3, 7, 14, 28, 365 or 730 (P > 0.05). CONCLUSION: CTN-Vero-RV was safe and effective as well as could generate a persistent immune response.

[Application of McAbs against rabies nucleocapsid in diagnosis of rabies street virus].

OBJECTIVE: McAbs against rabies nucleocapsid were used to detect rabies street viruses in animal brain specimens with indirect immunofluorescent assay to evaluate the sensitivity and specificity of this assay. METHODS: 62 specimen from rabid animal brains including genotype 1 to 7 and 271 specimens from different normal animal brains collected in Pasteur Institute in 2003 were tested and compared, using indirect immunofluorescent assay. All these specimens were identified and compared using rapid rabies enzyme immunodiagnosis, fluorescent antibody test and rabies virus isolation assay in neuroblastoma cell culture which were all provided by Pasteur Institute. RESULTS: Both sensitivity and the specificity of the indirect immunofluorescent assay were 100%. CONCLUSION: The results showed a positive of rabies virus detection with these methods.