Evaluation of soft tissue lesions affecting the masticator space with dynamic contrast enhanced MRI / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the characteristics and diagnostic value of dynamic contrast enhanced MRI (DCE-MRI) in differentiating benign soft tissue lesions from malignant tumors affecting the masticator space (MS).</p><p><b>METHODS</b>Prior to managements, conventional MRI and DCE-MRI were performed in 53 patients who suffered from primary or secondary soft tissue lesions affecting the MS. The time to peak (TTP), relative maximum enhancement (RME) and relative washout ratio (RWO) were separately calculated.</p><p><b>RESULTS</b>Mean TTP of benign and malignant lesions were (130.3 ± 13.2) and (69.6 ± 6.9) s, respectively. Mean RWO of benign and malignant lesions were (29.7 ± 5.5)% and (8.7 ± 2.1)%, respectively. Malignant lesions had a significantly shorter TTP(P = 0.001) and lower RWO (P = 0.003) than benign lesions. When TTP was less than 92.2 s and RWO less than or equal to 16.0%, malignant tumors were considered. DCE-MRI had a sensitivity of 72.3%, specificity of 93.5%, accuracy of 84.9%, positive predictive value of 88.9%, and negative predictive value of 82.9%.</p><p><b>CONCLUSIONS</b>As a non-invasive imaging technique, DCE-MRI is valuable to differentiate benign soft tissue lesions from malignant tumors affecting the MS.</p>

Study on the mechanism of HLA-I-expressing regulation caused by the core region mutation of HBV adr subtype / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the influence and mechanism of HBV core region mutation on HLA-I expression.</p><p><b>METHODS</b>Eukaryotic expression vectors of HBV core region mutations L97, G87 and V60 were constructed and transfected into HepG2 cells. Then the expressions of HLA-I were detected by RT-PCR and Western blot. The mRNA of antigen-presentation-associated genes, including LMP2, TAP1 and tapasin, were measured using RT-PCR.</p><p><b>RESULTS</b>Different levels of HBsAg in the supernatants of transfected cells were detected by ELISA. The HBsAg of the mutated groups was markedly higher than that of the wild ones. All the transfected cells expressed HLA-I molecules, especially the L97 group. It was also found that the mRNA of TAP1 gene was up-regulated, while the mRNA of LMP and tapasin genes had no changes.</p><p><b>CONCLUSION</b>The core region mutation of HBV can lower the expression of HBsAg; mutated groups and wild ones both can increase the expression of HLA-I molecules. The up-regulation of TAP1 gene expression might be the cause of these changes.</p>

Identification of a functional ITAM-like sequence within G1 cytoplasmic tail of Hantaan virus / 病毒学报

The G1 cytoplasmic tail of Hantaan virus (HTNV) harbors a highly conserved region, which is homologous to immunoreceptor tyrosine-based activation motifs (ITAM) and is termed the ITAM-like sequence. To demonstrate the potential signal-transducing activity of G1 ITAM-like sequence resembling the canonical ITAM within immune and endothelial cells, a series of experiments were performed to define its interaction with cellular kinases. The synthesized G1 ITAM-like peptide was shown to coprecipitate with cellular phosphoprotein complexes by an immune-complex kinase assay. Mutational analyses showed that this ITAM-like sequence was a substrate for the Src family kinase Fyn, and two conserved tyrosine residues were required for coprecipitating Lyn, Syk, and ZAP-70 kinases. These findings demonstrated that HTNV envelope glycoprotein G1 contains a functional ITAM-like sequence in its cytoplasmic tail, which can bind critical cellular kinases that regulate immune and endothelial cell functions.

Oral-maxillofacial malignant tumors: an initial study with in vivo single-voxel 1H MR spectroscopy / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the possibility of using single-voxel (1)H MR spectroscopy to evaluate malignant soft tissue tumors of oral-maxillofacial region.</p><p><b>METHODS</b>Forty-two patients with oral-maxillofacial malignant tumors, examined by single-voxel (1)H MR spectroscopy at a 1.5 T MR unit before treatment and confirmed by histo-pathological examination, were retrospectively studied. The localization for (1)H MR spectroscopy was used with a point-resolved spectroscopy (PRESS) at echo time of 144 ms. Choline (Cho), one of tumor's metabolites, was considered as a criterion to assess the malignant tumors.</p><p><b>RESULTS</b>Of 42 oral-maxillofacial malignant tumors, the Cho peak was identified in 37 lesions, including 15 of 17 squamous cell carcinomas, 9 of 12 salivary carcinomas, and 13 of 13 sarcomas and non-Hodgkin lymphomas.</p><p><b>CONCLUSIONS</b>Single-voxel (1)H MR spectroscopy might provide useful information for the assessment of malignant soft tissue tumors in the oral-maxillofacial region. Most malignant tumors in this study were characteristic of containing Cho metabolites. The Cho peak was more frequently recognized in the sarcomas and non-Hodgkin lymphomas than in the carcinomas.</p>

Computed tomography diagnosis of maxillofacial and neck malignant tumors invading carotid artery / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the diagnostic value of the carotid artery invasion by the oral-maxillofacial and neck malignant tumors with computed tomography (CT).</p><p><b>METHODS</b>Fifty-three patients (55 tumors) of oral-maxillofacial and neck malignant tumors were examined with enhanced axial CT examination in pre-operation. The CT manifestations of all tumors were retrospectively corresponded with the surgical findings.</p><p><b>RESULTS</b>Oral-maxillofacial and neck malignant tumors with abnormal common carotid artery (CCA) or internal carotid artery (ICA) manifestations were shown on CT as five types: type I, compression and deformation of CCA or ICA in six tumors; type II, displacement of CCA or ICA in 15 tumors; type III, the tumors encompass the carotid vessels more than 180 degrees in 8 tumors; type IV, the segmental deletion of fat or fascia planes between tumor and CCA/ICA in 25 tumors; and type V, ill-defined CCA/ICA wall in 12 tumors. Surgical findings recorded that 20 CCAs or ICAs were adhered by the oral-maxillofacial and neck malignant tumors. Of these 20 lesions, 14 malignant tumors (70%) with more than two abnormal changes of CCA or ICA were shown on CT images. The respective sensitivity, specificity and accuracy were 30.0%, 100.0% and 74.5% for type I, 20.0%, 68.6%, 50.9% for type II, 22.2%, 100.0%, 49.1% for type III, 90.0%, 80.0% and 83.6% for type IV, and 45.0%, 88.6% and 72.7% for type V.</p><p><b>CONCLUSIONS</b>The main CT findings of maxillofacial and neck malignant tumors affecting the carotid artery are different. Comparatively, the signs of type I, type III and type IV may be valuable in evaluating CCA or ICA invasion, although the accurate diagnosis of the CCA or ICA involvement by the maxillofacial and neck malignant tumors remains difficult.</p>