Objective:To study the alveolar bone morphology in the anterior teeth area of the skeletal Class Ⅱ malocclusion subjects with different vertical skeletal types.Methods:64 patients with skeletal Class Ⅱ malocclusion and 15 subjects with normal occlusion were included.The alveolar bone structure of the anterior teeth were observed using CBCT.Results:The labial and lingual alveolar bone height and the alveolar bone thickness of the incisors of the patients were much lower than those of the normal controls.The height of labial and lingual alveolar bone and the alveolar bone thickness of anterior teeth in high-angle subgroup were lower than those in low-angle subgroup.Conclusion:The thickness of the anterior teeth alveolar bone of skeletal Class Ⅱ malocclusion is low,espe-cially in the high-angle group.

Adult ; Bronchogenic Cyst ; Female ; Humans

ObjectiveTo compare the efficacy and safety of intermittent patient-initiated single-dose antibiotic prophylaxis and continuous antibiotic prophylaxis for the prevention of recurrent urinary tract infection (UTI) in postmenopausal women. MethodsA randomized controlled clinical trial was conducted for the prevention of recurrent urinary tract infection. Single dose of antibiotic was given every night in continuous antibiotic prophylaxis group and every time after exposure to conditions predisposed to UTI in intermittent antibiotic prophylaxis group. The duration of prevention was 12 months in both groups. ResultsThe effective rates of intermittent antibiotic prophylaxis and continuous antibiotic prophylaxis were 71.0% and 81.8% respectively (P＞0.05). The incidence of gastrointestinal adverse reaction in intermittent antibiotic prophylaxis group was significantly lower than that in continuous antibiotic prophylaxis group (7.7% vs 28.6%,P＜0.05). ConclusionsCompared with continuous antibiotic prophylaxis, intermittent patient-initiated single-dose antibiotic prophylaxis is a better prophylaxis with less gastrointestinal adverse reactions for the prevention of recurrent urinary tract infection in postmenopausal women.

Objective To extract principal components from valuable indicators on conventional ultrasoundand contrast-enhanced ultrasound (CEUS) in the differential diagnosis of thyroid benign and malignant lesions and to discuss the diagnostic value of each indicator.Methods One hundred and three patients with 125 thyroid lesions (65 malignant lesions and 60 benign lesions) underwent preoperative grayscale ultrasound (GSUS),color Doppler ultrasound (CDUS) and CEUS examinations.Eighteen indicators were chosen to evaluate every lesion and principal components were extracted by principal component and valuable indicators were ordered by importance.Results There were significant differences on GSUS and CEUS indicators between benign and malignant lesions.The first principal component was the representation of contrast enhanced ultrasound and was valuable in the differential diagnosis of thyroid benign and malignant lesions.The rank of valuable CEUS indicators were homogeneity of enhancement,filling defect,relative arrival time of periphery,peak interior echogenicity,relative arrival time of interior,peak peripheral echogenicity and ring enhancement.Conclusions GSUS and CEUS are valuable in the differential diagnosis of thyroid benign and malignant lesions.

Objective To investigate the relationship between ultrasound features and pathological types of primary hepatic lymphoma (PHL).Methods Ultrasound and pathological features in 26 cases of PHL were analyzed retrospectively.Results The most common presentation of PHL was a solitary lesion,which occurred in about 57.7％ (15/26) of cases,followed by multiple lesions in about 26.9％ (7/26) of patients,and least commonly as diffuse infiltration patterns in about 15.4％ (4/26) cases.The first two types were similar and usually demonstrated as hypoechoic lesions to the surrounding normal liver parenchyma in 86.4％ (19/22) of cases on ultrasound.All the cases were B-cell non-Hodgkin lymphoma proven by histological and immunohistochemical examinations.The diffuse pattern demonstrated diffuse hepatomegaly without nodular,which were T-cell non-Hodgkin lymphoma proven by histological and immunohistochemical examinations.Conclusions PHL could be divided into single,multiple and diffuse types on ultrasound.The single and multiple types mainly present as hypoechoic lesions and the diffuse type shows hepatomegaly on ultrasound,which are closely related to histology and T or B-cell phenotype on immunohistochemical examination.

BACKGROUND:Extracellular matrix can simulate microenvironment and make the stem cells proliferate maintaining the characteristics of stem cells wel in vitro. OBJECTIVE:To prepare the extracellular matrix from human bone marrow cells and to analyze its microstructure and composition preliminarily. METHODS:Human bone marrow cells of passage 4 were cultured for 14 days, and the induction medium was used during the last 8 days. After decellularization, cells were removed to prepare human bone marrow cells-derived extracellular matrix. The surface morphology of human bone marrow cells-derived extracellular matrix was observed by inverted microscope and scanning electron microscope. Changes of col agen I and biglycan before and after decellularization were observed by immunofluorescence staining. Human periodontal ligament stem cells were seeded onto human bone marrow cells-derived extracellular matrix, fibronectin coated 6-wel plate and normal culture plate to compare the influence of different matrix on cellmorphology and adhesion. RESULTS AND CONCLUSION:We obtained intact human bone marrow cells-derived extracellular matrix by chemical combined with physical decellularization. The structure and amount of col agen I and biglycan had not been compromised dramatical y after decellularization. Human periodontal ligament stem cells growing on the human bone marrow cells-derived extracellular matrix developed in accordance with the orbit of the extracellular matrix, differing from the original cellmorphology. There were more human periodontal ligament stem cells adhering to the extracellular matrix during the same time. These findings indicate that effective decellularization can produce intact the extracellular matrix membrane without destroying its microstructure. Extracellular matrix protein is not compromised due to decellularization. The extracellular matrix affects cellmorphology and promotes celladhesion. We can use the extracellular matrix model to simulate stem cellmicroenvironment and thereafter, acquire a large number of adult stem cells with high quality in vitro.

Objective To explore and evaluate MRI in diagnosing primary muscle non-Hodgkin lymphoma. Methods Six surgically confirmed primary muscle non-Hod#in lymphoma underwent MR examination including T_1WI, T_2WI and T_1 WI enhanced studies. The acquired images date was reviewed and analysed retrospectively in comparison with surgical and pathological results. Results The locations of 6 cases were cervical part (2), upper extremity (1), lower extremity (3), respectively. All cases involved of more than one anatomical compartment with poorly defined solid masses in 5 cases and well defined in 1 cases, 5 extended to subcutaneous fat and 3 extended along the neurovascular bundle. The mean tumor diameter was 13.9 cm, ranging from 7.3 to 22.5 cm. One was well demarcated and 5 were ill-defined. On T_1 WI, 2 were slighdy high signal intensity and 4 were slighdy low signal intensity. On T_2 WI, 2 were slightly high signal intensity, 3 were intermediate signal intensity and 1 was high signal intensity. Five were inhomogeneous and 1 was homogeneous. The intrinsic structure such as muscle fiber, tendo, spatium intermusculare were detected on 5 cases. Of the 5 dynamic contrast-enhanced cases, it showed moderate enhamcement during arterial phase, 2 were homogeneous and 3 were inhomogeneous. And it showed progressive enhancement during interstitial phase, 3 were homogeneous and 2 were inhomogeneous. Conclusions Primary muscle lymphoma always originated deep to the fascia showing subcutaneous extension and multiple compartment invasion. Typically form poorly defined solid masses with slightly high in signal intensity on MR T_2WI and middle degree dynamic delayed contrasted-enhanced in which intrinsic anatomic structure such as muscle fiber, tendo, spatium intermusculare and so on can be discerned, almost all cases involve more than one muscle compartment and some of tumor extend along the neurovascular bundle.

Objective To assess the value of ultrasonography(US)in the diagnosis of pancreas endocrine tumors(PET).Methods Thirty-six patients with PET confirmed by surgery and pathology were retrospectively reviewed.Results There were 37 PET in 36 patients,among which 33 tumors in 32 cases were detected bv US,four tumors were missed on US and the detection rate was 88.9%(32/36).The tumor size was 1.0 cm×0.8 cm～12.9 cm× 11.3 cm.Among 12 cases of equal to or less than 2 cm,9 tumors were detected and the detection rate was 75.0%.PET presented mostly hypoechogenicity(78.8%),other 7 cases presented mixed-echogenicity.Color Doppler US was performed on 12 cases and 11 tumors showed color blood signals.Abundant flow signal was detected in 8 tumors(66.7%).PET were found in pancreatic head (n=11),neck(n=2),body(n=6)and tail(n=11),which was diagnosed correctly in 30 cases (81.1%).Conclusions US is a useful tool in the detection and diagnosis of PET.

Objective To Explore the imaging features relative to pathology of pelvic chondrosarcoma and to evaluate the clinical value.Methods All 12 cases patients with primary pelvic chondrosarcoma confirmed by pathological examination underwent radiography,spiral CT plain scanning,MR SE-T1WI,FSE-T2WI and SE-Tl WI enhancement scanning before operation.The imaging data was reviewed and analyzed retrospectively to compare with surgical and pathological results.Results Eleven conventional chondrosarcoma and one dedifierentiated chondrosarcoma were located in different parts of pelvis.The diameters of the tumors ranged from 4.7 to 17.0 cm with one case less than 5.0 cm,6 cases being 5.O-10.0 am and 5 cases more than 10.0 Cln.The CT valHe of 5 cases was identical or inferior to muscle with mild to moderate"ring-and-arc"mineralization and soft mass.MR imaging depict the high water content of these lesions as very high signal intensity was detected on T2 WI.Six cases showed typical"ring-and-arc"fibrous tissue which enhanced persistently.Aggressive features of deep endosteal scalloping and soft-tissue extension was also found in these cases.Conclusions Radiographic findings Can suggest the diagnosis of pelvic chondrosarcoma when there is typical"ring-and.arc"fibrous tissue,mineralization,aggressive features of deep endosteal scalloping and large soft-tissue extension.MR imaging reflect directly this pathologic structure,superior to that of CT and radiography.CT is optimal to detect the matrix mineralization,particularly when it is subtle or when the lesion is located in anatomically complex pelvic areas.

Objective To explore the imaging features of primary malignant fibrous histiocytoma(MFH)of bone and correlate them with pathological findings.Methods Thirteen cases patients with primary MFH of bone confirmed by surgical pathology underwent radiography,spiral CT plain scanning and MR SE-T1 WI,T2 WI and SE-T1 WI enhancement scanning before operation.The imaging date was reviewed and analysed retrospectively in comparison with surgical and pathological results.Results Of 13 MFH,11 were located in the end of long bone,and 2 in the diaphysis.The distance between tumors in the end of long bone and adjacent joint surface was 1 to 5 cm.All lesions showed osteolytic destruction with the maximum diameter of the tumors from 5.3 to 12.7 cm.The tumors had eccentric aggressive osteolytic destruction in 10 lesions,internal crest within the lesions in 7,inconsecutive marginal osteosclerosis in 11,little periosteal reaction in 2 and small soft tissue masses in 9,respectively.The CT value of lesions was similar to muscle.MR imaging depicted low signal intensity with aggressive features on T1 WI,iso to slight high signal intensity on T2 WI,and middle or high degree contrast enhancement on enhanced T1 WI images.Macroscopically,MFH was usually located eccentrically within the bone and produced little or no osseous expansion.The soft tissue component appeared multi-nodules and pseudo-encapsulated.Histologically,they consisted of spindle-shaped fibroblasts,which radiated outward in a spiral array from a central focus and produced a nebula or storiform appearance,and cells,which were small and oval with little visible cytoplasm.Conclusions The imaging manifestations of MFH were specific to some extent.Combined utilization of plain X-ray,CT,and MRI is helpful for the diagnosis and differential diagnosis of MFH.