The value of DTI: achieving high diagnostic performance for brain metastasis.

BACKGROUND: The evaluation of brain metastases generally requires post-contrast MRI exam, but some patients have contraindication to contrast medium administration. PURPOSE: To investigate the value of the MRI diffusion tensor imaging (DTI) for detection of metastatic brain tumor. MATERIALS AND METHODS: We retrospectively analyzed the MRI data from 23 patients (13 males and 10 females) with brain metastases. The MRI protocol consisted in T1WI, T2WI, post-contrast 3DT1WI and DTI images (b = 1000) sequences. The brain metastatic lesions were counted in each of these sequences. We compared the advantages and limitations of different sequences in the brain metastases detection. The number of metastatic lesions identified on the contrast-enhanced 3DT1WI image is used as the reference. FA values were measured in the intratumoral, adjacent peritumoral and distant peritumoral edema area (PTEA) of brain metastasis, and the differences were statistically analyzed. RESULTS: DTI can detect more brain metastatic lesions rather than T1WI and T2WI. The number of brain metastases on DTI is similar to post-contrast 3D T1WI. There is no statistical difference in the FA value change between the adjacent and distant PTEA. CONCLUSION: The DTI original image can be used as an alternative examination for patients with contraindications to contrast-enhanced MRI. It has high sensitivity to intratumoral hemorrhage, which has advantage to detect brain metastatic lesions as compared with T1WI or T2WI images.

Research on the current implementation and management of key clinical specialty programs in Guangzhou / 中华医院管理杂志

Objective:To study the problems found in the implementation of key clinical specialty programs and come up with feasibility suggestions.Methods:November 2020 to January 2021, by means of quota sampling and snowball sampling, 22 depth interviews were made with principal-investigators, project team elites, leaders of functional departments, and experts of independent examination teams. The interview data were subject to theme analysis.Results:Six(27%) of the interviewees confused the concepts of " key specialty" and " key discipline" ; 9(41%) of them held that at specific stage of the program development, the connotation and implementation emphasis of specialty development and those of key disciplines were overlapped to some extent. Twenty(88%)of them held that functional management process and responsibility should be further refined, 19(86%) said that lack of professional financial knowledge hindered their program implementation, 16(73%) reported difficulties in information statistics, management and sharing, 19(86%)presented disputes in understanding the program examination criteria.Conclusions:In the implementation of key clinical specialty program, management at various levels should work in alignment with program teams, provide accurate definition and guidance to key steps and working mechanisms, refine the management process, provide accurate financial management, and build information platforms for big data collection and sharing.

Laboratory diagnosis of rarely filamentous fungi / 军事医学

Objective To investigate the laboratory diagnosis of filamentous fungi which are rarely seen in clinical practice.Methods Five strains of fungi were isolated from clinical samples and initially identified by the morphological method.Total DNA of fungi was extracted and amplified by the PCR method using universal primers of ITS2-ITS4 gene, respectively.The PCR products were sequenced and the obtained sequences were then analyzed by the blastn program incorporated in NCBI.Results The five strains of fungi were diagnosed as Scedosporium apiospermum,Schizophyllum commune,Scopulariopsis brevicaulis,Rhizopus stolonifer,and Fusarium solani.Conclusion The laboratory diagnosis of filamentous fungi which rarely occur in clinical practice should integrate various methods,including morphological, microbiological,and molecular biological methods.

Expression, purification and enzymatic characteristics of 2-hydroxyacid dehydrogen-ase from Ketogulonigenium vulgare Y25 / 军事医学

Objective To clone 2-hydroxyacid dehydrogenase (HADH) gene from Ketogulonigenium vulgare(KGV) Y25 and investigate its expression , purification, and enzymatic characterics .Methods The hadh gene was amplified from ketogulonigenium vulgare Y 25 and cloned into the expression plasmid pITG .The recombinant plasmid was transformed into Escherichia coli BL21(DE3).HADH was then successfully expressed with induction .To explore its enzymatic characteris-tics,HADH was purified by Ni +exchange chromatography .Results HADH constituted more than 50% of the total cell proteins analyzed by SDS-PAGE,with a relative molecular mass of about 35 ×103.With 2-keto-gulonic acid(2-KGA) as substrate, the optimal pH of HADH was at 8.0 ,while the optimal temperature of the purified HADH was at 45℃.Mean-while, such metal ions and chelating agents as Cu 2+, Ca2+, Mg2+, EDTA, and DEPC exerted little effect on enzymatic activities.The maximum initial activity of the enzyme towards 2-KGA reached 27 U/mg, and the Km was calculated as 2.6 mmol/L.The results of in vivo enzyme activity assay showed that HADH could metabolize 2-KGA.Conclusion The HADH gene form Y25 is successfully expressed in E.coli BL21 ( DE3 ) and the enzymatic characteristics of HADH are explored, which will facilitate subsequent studies on sorbose metabolic pathways and sugar acid conversion .

Comparison of temporomandibular joint injuries after three-dimensional conformal and intensity-modulated radiotherapies for nasopharyngeal carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the radiation injuries of the temporomandibular joint (TMJ) following three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>Thirty-nine NPC patients without previous radiotherapy underwent 3D-CRT and another 32 received IMRT in our institute. The distance between the 2 dens incisivus medialis (DDIM) and LENT SOMA criteria were employed to evaluate TMJ injuries, clinical outcomes, and the performance-to-price ratios.</p><p><b>RESULTS</b>The short-term local response rates were similar between the two groups (P=0.878). The mean radiation doses of the TMJ were significantly higher in 3D-CRT group than in IMRT group (57.06 vs 40.90 Gy, P<0.001). The DDIM showed significant changes in 3D-CRT groups after the radiotherapy (P<0.05). No significant difference was found in the TMJ injuries between the two groups according to the SOMA criteria (P>0.05).</p><p><b>CONCLUSION</b>Radiation injuries of the TMJ are tolerable in both 3D-CRT and IMRT groups, and 3D-CRT is a more economic choice for patients who can not afford IMRT.</p>