Effect of various intracanal materials on the diagnostic accuracy of cone-beam computed tomography in vertical root fractures / 北京大学学报(医学版)

OBJECTIVE@#To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF).@*METHODS@#A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists.@*RESULTS@#The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001).@*CONCLUSION@#Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.

Measurement of the weight and volume of submandibular gland in vitro / 北京大学学报(医学版)

OBJECTIVE@#To measure the weight and volume of normal submandibular gland by in vitro detection of glandular body, to compare with the measurement values of CT volume rendering to evaluate the consistency of the two methods, and to explore the related factors affecting the weight and volume of the submandibular gland.@*METHODS@#The patients who underwent neck dissection due to oral cancer and were confirmed with normal submandibular gland by postoperative histopathology in Peking University School and Hospital of Stomatology from May 2019 to January 2020 were collected in this study and divi-ded into 4 groups according to the age standards raised by the Society of Geriatrics Chinese Medical Association and WHO (2000) age standards. The submandibular gland was carefully dissected along with the capsule immediately after neck dissection. The weight and volume of submandibular gland were accurately measured by an integrated aseptic measuring device. The volume of submandibular gland was measured by CT volume rendering before operation and the consistency of the two methods was evaluated. The 95% confidence interval of the weight and volume of submandibular gland in the different groups of Chinese people, which were divided by gender and age, were calculated, and the correlation with age, gender, height, weight, body mass index (BMI) and other factors was analyzed.@*RESULTS@#The weight and vo-lume of submandibular gland were measured in 220 subjects. The average weight and volume of submandibular gland were (11.69±2.45) g and (11.55±2.41) cm3 respectively. The volume of submandibular gland measured by CT volume rendering ranged from 70% to 82% of that measured by in vitro detection of glandular body, and the correlation coefficient between the two methods was 0.976 (P < 0.05). The gender difference of weight and volume of submandibular gland existed in the groups of youth, middle-aged, young elderly and elderly groups, the values of males were obviously higher than those of females (P < 0.05). There was no gender difference of weight and volume of submandibular gland in the adolescent group (P > 0.05). The weight and volume of submandibular gland had a strong positive correlation with body height (P < 0.05), a weak positive correlation with body weight (P < 0.05), and no correlation with BMI (P > 0.05). The female's weight and volume of submandibular gland in the young elderly and elderly groups were significantly lower than those in the other three groups (P < 0.05).@*CONCLUSION@#The normal reference range of the weight and volume of submandibular gland in vitro were established in different age and gender groups of Chinese people. The volume of submandibular gland mea-sured by CT volume rendering was 70%-82% of that measured by in vitro detection of glandular body. The results of the two methods had a high degree of consistency. The weight and volume of submandibular gland were related to age, gender, body height and body weight.

Parotid CT imaging reporting and data system: A preliminary study / 北京大学学报(医学版)

OBJECTIVE@#To establish a Parotid Imaging Reporting and Data System (PI-RADS) for CT diagnosis of the parotid gland neoplasms and to investigate the clinical applicable value and feasibility of PI-RADS.@*METHODS@#Patients who had been diagnosed with primary parotid gland neoplasms and had received surgical treatments in Peking University School and Hospital of Stomatology during the period of January 2013 to December 2016 were included in this study. The diagnoses were confirmed by the postoperative pathological examinations in all the patients. The CT imaging data of all patients were retrospectively reviewed and analyzed by two readers in consensus. Imaging characteristics related to the parotid neoplasms were extracted and quantified. Based on comprehensive analysis of the imaging characteristics, the probabilities of the benign and malignant neoplasms were evaluated and classified into six grades, PI-RADS 1-6 (PI-RADS 1: normal parotid gland; PI-RADS 2: confidently benign lesions; PI-RADS 3: probably benign lesions without confirmed evidence of malignancy; PI-RADS 4: suspected malignancy without sufficient evidence of malignancy; PI-RADS 5: confidently malignant lesions; PI-RADS 6: lesions with confirmed pathological evidence of malignancy).@*RESULTS@#A total of 897 patients with 1 003 parotid lesions were included. The lesions included 905 benign and 98 malignant lesions. The proportions of the malignancies in PI-RADS 2, PI-RADS 3, PI-RADS 4 and PI-RADS 5 according to the two readers in consensus were 0.4%, 5.7%, 35.5% and 96.7% respectively. The overall Cohen's Kappa test showed medium consistency between the two independent researchers (κ=0.614, P<0.001, 95%CI: 0.569-0.695). Pearson Chi-square test showed that the proportions of malignancies increased with the diagnostic PI-RADS grades (Cochran-Armitage trend test, Z=-15.579, P<0.001). The results of Pearson Chi-square tests showed significant differences between the grades [PI-RADS 2 and 3 (χ²=12.048, P=0.001); PI-RADS 3 and 4 (χ²=75.231, P<0.001); PI-RADS 4 and 5 (χ²=32.266, P<0.001)].@*CONCLUSION@#PI-RADS can be used to evaluate the risk of malignancy and will be helpful to improve the imaging diagnosis and clinical treatment of parotid gland neoplasms.

Computed tomographic features of desmoplastic ameloblastoma of the jaw / 北京大学学报(医学版)

OBJECTIVE@#To retrospectively analyze the clinical and CT imaging features of desmoplastic ameloblastomas (DA) in comparison with other types of ameloblastomas.@*METHODS@#Patients diagnosed with ameloblastoma histopathologically in Peking University School and Hospital of Stomatology from July 2000 to August 2017 were reviewed to analyze the constituent ratios and characteristics of DA. CT imaging features of DA (28 cases) were investigated in comparison with consecutive cases of solid/multicystic and unicystic ameloblastomas. The following imaging perspectives were analyzed: the border, internal structure, three-dimensional shape, tooth, the periodontium, the cortex and the expansion of the tumors. CT values were measured in the region of interest for quantitative analysis.@*RESULTS@#Among the 1 269 cases of ameloblastomas, 50 (3.9%) were DA, which showed predilections for males (74.0%). The average age of DA was about 43.9 years old, which was higher than the other two types. The anterior incisorcanine region (62.0%) and premolar region (30.0%) were most frequently affected. The incidence rate of DA in mandibule was 56.0% (28/50), which was slightly higher than that of maxilla (44.0%). The DA characteristically showed scallop border and honeycomblike or soapbubble internal structure with bone formation on CT. The mean ratios of height to mesiodistal and buccal-lingual to mesio-distal distances were 0.76 and 0.63, which were higher than the other two types. According to the degree of internal bone formation, three subtypes of DA could be observed: densely ossifying type (I), honeycomb/soap bubble type (II) and sparsely ossifying type (III). The means and standard deviations of CT values of DA were significantly higher than those of the other two types, which were (488.8±164.0) HU (type I), (171.7±102.8) HU (type II), (42.1±8.8) HU (type III).@*CONCLUSION@#CT is helpful for diagnosis of DA, which shows as solid tumor with varying degrees of internal ossification.

Clinicopathological characteristics and diagnosis of IgG4related sialadenitis / 北京大学学报(医学版)

Immunoglobulin G4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated disease and one of immunoglobulin G4-related diseases (IgG4-RD). Our multidisciplinary research group investigated the clinicopathological characteristics and diagnosis of IgG4-RS during the past 10 years. Clinically, it showed multiple bilateral enlargement of major salivary glands (including sublingual and accessory parotid glands) and lacrimal glands. The comorbid diseases of head and neck region including rhinosinusitis, allergic rhinitis, and lymphadenopathy were commonly seen, which could occur more early than enlargement of major salivary glands. Internal organ involvements, such as autoimmune pancreatitis, sclerosing cholangitis, and interstitial pneumonia could also be seen. Thirty-five (38.5%) patients had the symptom of xerostomia. Saliva flow at rest was lower than normal. Secretory function was reduced more severely in the submandibular glands than in the parotid glands. Serum levels of IgG4 were elevated in almost all the cases and the majority of the patients had increased IgE levels. CT, ultrasonography, and sialography showed their imaging characteristics. Histologically it showed marked lymphoplasmacytic inflammation, large irregular lymphoid follicles with expanded germinal centers, prominent cellular interlobular fibrosis, eosinophil infiltration, and obliterative phlebitis. Their immunohistological examination showed marked IgG-positive and IgG4-positive plasma cell infiltration and high IgG4/IgG ratio. The disease could be divided into three stages according to severity of glandular fibrosis. The serum IgG4 level was higher and the saliva secretion lower as glandular fibrosis increased. IgG4-RS should be differentiated from other diseases with enlargement of major salivary gland and lacrimal gland, such as primary Sjögren syndrome, chronic obstructive submandibular sialadenitis, and eosinophilic hyperplastic lymphogranuloma.

Aminopeptidase N: A therapeutic target in human liver cancer stem cells / 国际药学研究杂志

Liver cancer stem cells (LCSC) play the critical role in hepatocellular carcinoma development and maintenance. They are generally dormant or slowly cycling tumor cells that have the ability to reconstitute tumors. LCSC associate closely with tumor resistance to chemo/radiation therapy, tumor relapse and metastasis, and can be identified and separated with some special surface markers from hepatocellular carcinoma, such as CD133, CD90, CD44, CD24 and EpCAM to investigate the biological behaviors of them. Early studies showed that these markers can be regarded as special surface markers of liver cancer stem cells. Recent studies found that aminopeptidase N (APN, CD13+) cells in hepatocellular carcinoma have biological characteristics of stem cells and demonstrated that CD13 is a marker for semiquiescent CSC in human liver cancer cell lines and clinical samples and that targeting these cells might provide a way to treat this disease. In this review, we introduce the structure and the main function of CD13, liver cancer stem cells source and identification, CD13+ CSC in hepatocellular carcinoma and combination therapy in the treatment of liver cancer.

Characterization of an iridovirus detected in rock bream (Oplegnathus fasciatus; Temminck and Schlegel) / 病毒学报

During the summer of 2009, mass mortality was observed in cage-cultured Rock Bream (Oplegnathus fasciatus; Temminck and Schlegel) in the Liaoning Province. Histopathogic studies of the affected fish showed enlarged basophilic cells in the kidney and spleen. These necrotic cells were stained purple using haematoxylin and eosin (HE). GF cell cultures showed advanced cytopathic effects after infection with virus supernatants from diseased fish homogenate. Transmission electron microscopy revealed hexagonal outlines virions in the cytoplasm of the spleen, kidney, liver, intestine cells. The viral particles consisted of a central nucleocapsid (100-110 nm) and envelope, and were 150-180 nm in diameter. These results suggested that the virus belonged to the Iridoviridae. Using polymerase chain reaction (PCR), approximately 570-bp fragments were amplified from the viral DNA in spleen, kidney, gill, intestine, heart and brain of diseased fish with the primers derived from red sea bream Iridovirus (RSIV). In addition, a specific fragment of 1 400 bp of the major capsid protein (MCP) gene of the Iridovirus was amplified by PCR. A phylogenetic tree was constructed to compare the corresponding genetic sequences in Megalocytivirus. The tree demonstrated that RSIV-LN09 virus existed in the same branch as the RSIV-U1 et al. Our present results indicated that RSIV was the causative agent.