Value of T6SS Core Gene hcp in Acinetobacter baumannii Respiratory Tract Infection.

Hospital-acquired pneumonia caused by Acinetobacter baumannii is a major healthcare burden. Type VI Secretion System (T6SS) contributes to both virulence and drug resistance in this bacteria. This study aims to investigate the diagnostic value of hemolysin co-regulated protein (Hcp) gene in A. baumannii pneumonia and further explore the effect of hcp on clinical, pathogenicity and drug resistance. 53 clinical A. baumannii strains from patients' respiratory tract at a teaching hospital were included in this study. Real-time quantitative polymerase chain reaction (qRT-PCR) was carried out to examine the expression of hcp. Recombinant Hcp expression plasmids (pET-28a(+)-hcp) were constructed and his-tagged Hcp were purified to stimulate Tohoku Hospital Pediatrics-1 (THP-1) macrophages. Nuclear Factor Kappa B p65 (NF-κBp65) and Interleukin 8 (IL-8) were detected by qRT-PCR. Antimicrobial susceptibility testing (AST) were examined by an automated instrument system. Hcp gene had 92.6% sensitivity and 75% specificity for distinguishing invasive or colonizing A. baumannii from the respiratory tract. His-tagged Hcp induced NF-κBp65 and IL-8 at gene level in THP-1 macrophages. Additional, high hcp expression isolates showed higher rate of antimicrobial agent exposure (< 30 days) of carbapenems, antibiotic combination therapy and multiple or extensive drug-resistant (MDR/XDR) and exhibited higher resistance rate to clinical commonly-used antimicrobial agents. Hcp gene could serve as a novel diagnostic biomarker to distinguish A. baumannii respiratory tract infection from colonization and participate in eliciting inflammatory responses in vitro. T6SS/hcp may play a role in the development of carbapenem-resistant A. baumannii (CRAB), multiple or extensive drug-resistant A. baumannii (MDRAB/XDRAB). Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01083-8.

[Research on algorithms based on Markov random models for diffusion tensor-magnetic resonance images].

With the utilization of diffusion tensor information of image voxels, a novel MRF (Markov Random Field) segmentation algorithm was proposed for diffusion tensor MRI (DT-MRI) images benefitted from the introduction of Frobenius norm. The comparison of the segmentation effects between the proposed algorithm and K-means segmentation algorithm for DT-MRI image was made, which showed that the new algorithm could segment the DT-MRI images more accurately than the K-means algorithm. Moreover, with the same segmentation algorithm of MRF, better outcomes were achieved in DT-MRI than in conventional MRI (T2WI) image.

[Genetic algorithm-based dose optimization in intensity modulated radiation therapy].

As a powerful global optimization approach, genetic algorithms (GA) can solve a variety of optimization problems in which the objective function is discontinuous, non-differentiable, or highly non-linear, to produce high convergence speed and vast search space. In this thesis, GA is used to optimize the beam weights of intensity modulated radiation therapy (IMRT) inverse planning, and 2D and 3D isodose contour as well as dose volume histogram (DVH) are used to evaluate the treatment plan. Also presented in this thesis are the results of calculation with discussions.

[A preliminary study of beam weight optimization of intensity-modulated radiation therapy with genetic algorithm].

UNLABELLED: To study the method for dose calculation and beam weight optimization of intensity-modulated radiation therapy (IMRT). METHODS: The IMRT dose calculation model based on two-dimensional convolution was constructed, the program of dose calculation and beam weight optimization with genetic algorithm was written with Visual c#.Net, and the optimization results were analyzed. RESULTS: Genetic algorithm optimization of beam weights can produce highly conformal dose distributions within a clinically acceptable computation time. CONCLUSION: Genetic algorithm is valid and efficient in IMRT beam weight optimization, which may facilitate IMRT treatment planning.

[A new method for static intensity-modulated radiation therapy].

OBJECTIVE: To develop a new method for static intensity-modulated radiation therapy (IMRT) possible for implementation in smaller hospitals by incorporating accurate location equipments and treatment planning system in the available equipments for general radiotherapy. METHODS: Based on the techniques of conformal radiotherapy, a new split method for fabricating the three-dimensional physical compensator was developed to achieve IMRT. RESULTS: Experiment with the new method showed that the fabricated compensator could achieve good match between the high dosage shape in the target area and the dimensions of the tumor, and allowed adjustment of the dosage distribution according to the therapeutic requirement. CONCLUSION: This simple and feasible method allows cost-effect application of IMRT in smaller hospitals.

[Development of a new system for head and neck stereotactic conformal radiotherapy].

This paper introduces the constitution and fabrication of the new head and neck stereotactic conformal radiotherapy system. It remedies the shortages in the head and neck stereotactic conformal radiotherapy at present and it is deserved to be popularized in clinical applications.

[A study on the relation between the location of brain damage and agraphia of Chinese].

OBJECTIVE: To investigate the relation between the location of brain damage and Chinese agraphia. METHODS: Aphasia Battery of Chinese (ABC) and Chinese Agraphia Battery (CAB) were used to examine the ability of oral language and writing. Different types of aphasia and agraphia were detected. Computerized image-processing technology was used to standardize and reconstruct the skull CT/MRI images. The results substracted from the normal controls were shown directly. RESULTS: 48 patients had lesions on the left brain among them 30 were aphasic and 32 were agraphic. 15 had lesions on the right brain, among them 3 were aphasic and agraphic. The image-processing results showed that the nidi of aphasic agraphia located on the left deep albae of frontal and parietal lobe, the nidi of persistent agraphia located on the posterior parts of the left 1st and 2nd gyrus of frontal lobe and the nidi of mirror agraphia were dispersed near the left basal ganglion and thalamus. CONCLUSIONS: It is found that there is a relationship between Chinese agraphia and the location of brain damage. Some parts may be responsible for some special writing ability.

[The automatic optimization arithmetic of selecting beam arcs in X-knife radiotherapy planning system].

In this paper, two new concepts of DR (Dose Repulsion) and DG (Dose Gravitation) are presented with their calculation formulas. For the problem of selecting beam arcs in x-knife radiotherapy Planning system, a mathematics model of constrained optimization has been built. Furthermore, we have produced a feasible project of automatic selecting optimized beam arcs plan using SA (Simulated Annealing) arithmetic based on the distribution of the fields of DR and DG in the reduced phase space.