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Background: Differentiation of postoperative neck abscess from non-infected fluid is important because the treatment is different. Purpose: To determine specific CT findings that might help to differentiate abscesses from non-infected fluid collections in the postoperative neck. Material and Methods: We retrospectively reviewed CT scans of 50 patients (43 men and 7 women; mean age, 62.5 ± 8.9 years) who had postoperative fluid collections in the neck (26 abscesses and 24 non-infected fluid collections). Diagnosis of an abscess was determined by a positive bacteria culture from the fluid collection. Diagnoses were correlated with the following CT findings: anatomic spaces involved, the maximum transverse diameter, margin, attenuation, rim enhancement, gas bubbles, and manifestations of soft tissue adjacent to a fluid collection. Results: Rim enhancement pattern and soft tissue manifestations showed significant differences between abscess and non-infected fluid. The reliable CT findings for abscess were: (i) rim enhancement > 50% of the circumference, 54% sensitive, 71% specific, and 62% accurate; and (ii) severe soft tissue manifestations, 39% sensitive, 92% specific, and 64% accurate. There were no significant differences in the anatomic spaces involved, the maximum transverse diameter, margin, attenuation, and gas bubbles between abscess and non-infected fluid. Conclusion: CT findings that may help differentiate postoperative neck abscess from non-infected fluid were rim enhancement > 50% of the circumference and severe soft tissue manifestations. [ABSTRACT FROM AUTHOR]

Objectives: To compare the diagnostic performance of ultrasound, contrast-enhanced computed tomography (CT) and (18)F-FDG positron emission tomography (PET)/CT for detecting recurrent differentiated thyroid cancer in the neck.Methods: Twenty patients who had undergone previous surgery for differentiated thyroid cancer (19 papillary carcinomas; 1 medullary carcinoma) and presented with pathologically proven recurrence in the neck were included. All patients had undergone ultrasound, CT and PET/CT in the 2 months before further surgery. In each patient, ultrasound, CT and PET/CT images were retrospectively reviewed to determine the presence of loco-regional recurrence by level-by-level analysis. Imaging results were correlated with the histological evaluation of the neck dissection as a standard of reference.Results: Recurrences were found at 52 out of 110 cervical nodal levels surgically explored. The sensitivity, specificity and accuracy were 69.2 %, 89.7 % and 80.0 % for ultrasound; 63.5 %, 94.8 % and 80.0 % for CT; and 53.8 %, 79.3 % and 67.3 % for PET/CT, respectively. ROC analysis revealed higher diagnostic performance with ultrasound than with PET/CT for detecting recurrent tumour.Conclusions: Although no significant difference was found among the three techniques, the sensitivity and specificity of ultrasound and CT were higher than those of PET/CT for the evaluation of cervical recurrence in patients with differentiated thyroid cancer.Key Points: • Ultrasound, CT and ( 18 ) F-FDG PET/CT can all detect recurrent thyroid cancer. • Ultrasound and CT have higher sensitivity and specificity. • Ultrasound, CT and ( 18 ) F-FDG PET/CT frequently demonstrated discordant findings. [ABSTRACT FROM AUTHOR]

Background: Computed tomography angiography (CTA) is increasingly used for non-invasive imaging of the cerebrovascular diseases. Purpose: To evaluate the accuracy of CTA in the assessment of the variation of the segment calibers of the circle of Willis. Material and Methods: One hundred and 17 patients with acute SAH (51 men and 66 women, mean age 50.9 years) who underwent CTA using a 16 detector-row CT scanner and DSA were evaluated retrospectively. The CTA and DSA studies were performed within 24 h after the onset of symptoms and within 24 h of each other. A total of 819 arterial segments (A-comA, right and left A1 segment, right and left P-com A, and right and left P1 segment) of the circle of Willis were determined to be aplastic (grade 1), hypoplastic (grade 2), or normal-sized (grade 3) by blinded observers evaluating CTA volume-rendered images. The CTA results were then compared with findings on the corresponding DSA images (reference standard). Results: The overall agreement between CTA and DSA was 92.4%. We had 62 (7.6%) cases of disagreement (58 cases of under-estimation and four cases of over-estimation by CTA) between tow modalities. The sensitivity and specificity of CTA in the detection of aplastic and normal-sized segments were more than 90%. In contrast, subgroup analysis of the hypoplastic segments showed a sensitivity of 52.6% and a specificity of 98.2%. Conclusion: CTA is highly accurate in the assessment of anatomical variations of the circle of Willis; however, its sensitivity is limited in depicting hypoplastic segments. [ABSTRACT FROM AUTHOR]

Background: a reliable assessment of mandibular invasion is crucial for treatment planning to obtain both radical tumor resection and good functional results. Purpose: to retrospectively compare the diagnostic value of three different imaging methods - computed tomography (CT), magnetic resonance (MR) imaging, (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT - and their combined use for detection of mandibular invasion by squamous cell carcinoma (SCC) of the oral cavity. Material and Methods: forty-six patients (39 men and 7 women; mean age, 59.4 years) suspected of having mandibular invasion by SCC of the oral cavity underwent CT, MR, and PET/CT within 2 weeks before surgery. First, each study was reviewed separately for the presence of mandibular invasion by tumors. Then, the value of combined images was assessed based on a confidence rating score for each modality assigned by observers. These results were verified with histopathologic findings. Results: HIstopathologic examination revealed mandibular invasion in 12 of 46 SCCs. The sensitivity, specificity, and accuracy were 41.7%, 100%, and 84.8% for CT; 58.3%, 97.1%, and 87.0% for MR; and 58.3%, 97.1%, and 87.0% for PET/CT, respectively. The comparison of these modalities showed no statistically significant difference among them (P > 0.05). The combination of CT, MR, and PET/CT improved sensitivity (83.3%), without loss of specificity (100%) and accuracy (95.7%), although the difference failed to reach statistical significance (P > 0.05). Conclusion: the combined analysis of CT, MR, and PET/CT can improve sensitivity in the detection of mandibular invasion by SCC of the oral cavity. [ABSTRACT FROM AUTHOR]

The purpose of this retrospective study was to compare the diagnostic value of four different imaging methods-computed tomography (CT), magnetic resonance (MR) imaging, ultrasonography (US), and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT-and their combined use for preoperative detection of cervical nodal metastases in head and neck squamous cell carcinoma (SCC). Sixty-seven patients (58 men and 9 women; mean age, 60.1 years) with head and neck SCCs underwent CT, MR, US, and PET/CT before surgery. First, each study was reviewed separately for the presence of nodal metastases. Then, the value of combined images was assessed based on a confidence rating score for each modality assigned by observers. These results were verified, on a level-by-level basis, with histopathologic findings. Histopathologic examination revealed nodal metastases in 74 of 402 nodal levels. The sensitivity, specificity, and accuracy were 77.0%, 99.4%, and 95.3% for CT and MR; 78.4%, 98.5%, and 94.8% for US; and 81.1%, 98.2%, and 95.0% for PET/CT, respectively. The comparison of these modalities showed no statistically significant difference among them (p > 0.05). The combination of CT, MR, US, and PET/CT improved sensitivity (86.5%), without loss of specificity (99.4%) and accuracy (97.0%), although the difference failed to reach statistical significance. [ABSTRACT FROM AUTHOR]

Background and Purpose: The effects of 4-O-methylhonokiol (MH), a constituent of Magnolia officinalis, were investigated on human prostate cancer cells and its mechanism of action elucidated.Experimental Approach: The anti-cancer effects of MH were examined in prostate cancer and normal cells. The effects were validated in vivo using a mouse xenograft model.Key Results: MH increased the expression of PPARγ in prostate PC-3 and LNCap cells. The pull-down assay and molecular docking study indicated that MH directly binds to PPARγ. MH also increased transcriptional activity of PPARγ but decreased NF-κB activity. MH inhibited the growth of human prostate cancer cells, an effect attenuated by the PPARγ antagonist GW9662. MH induced apoptotic cell death and this was related to G(0) -G(1) phase cell cycle arrest. MH increased the expression of the cell cycle regulator p21, and apoptotic proteins, whereas it decreased phosphorylation of Rb and anti-apoptotic proteins. Transfection of PC3 cells with p21 siRNA or a p21 mutant plasmid on the cyclin D1/ cycline-dependent kinase 4 binding site abolished the effects of MH on cell growth, cell viability and related protein expression. In the animal studies, MH inhibited tumour growth, NF-κB activity and expression of anti-apoptotic proteins, whereas it increased the transcriptional activity and expression of PPARγ, and the expression of apoptotic proteins and p21 in tumour tissues.Conclusions and Implication: MH inhibits growth of human prostate cancer cells through activation of PPARγ, suppression of NF-κB and arrest of the cell cycle. Thus, MH might be a useful tool for treatment of prostate cancer. [ABSTRACT FROM AUTHOR]

Background and Purpose The effects of 4- O-methylhonokiol ( MH), a constituent of Magnolia officinalis, were investigated on human prostate cancer cells and its mechanism of action elucidated. Experimental Approach The anti-cancer effects of MH were examined in prostate cancer and normal cells. The effects were validated in vivo using a mouse xenograft model. Key Results MH increased the expression of PPARγ in prostate PC-3 and LNCap cells. The pull-down assay and molecular docking study indicated that MH directly binds to PPARγ. MH also increased transcriptional activity of PPARγ but decreased NF- κB activity. MH inhibited the growth of human prostate cancer cells, an effect attenuated by the PPARγ antagonist GW9662. MH induced apoptotic cell death and this was related to G0- G1 phase cell cycle arrest. MH increased the expression of the cell cycle regulator p21, and apoptotic proteins, whereas it decreased phosphorylation of Rb and anti-apoptotic proteins. Transfection of PC3 cells with p21 si RNA or a p21 mutant plasmid on the cyclin D1/ cycline-dependent kinase 4 binding site abolished the effects of MH on cell growth, cell viability and related protein expression. In the animal studies, MH inhibited tumour growth, NF- κB activity and expression of anti-apoptotic proteins, whereas it increased the transcriptional activity and expression of PPARγ, and the expression of apoptotic proteins and p21 in tumour tissues. Conclusions and Implication MH inhibits growth of human prostate cancer cells through activation of PPARγ, suppression of NF- κB and arrest of the cell cycle. Thus, MH might be a useful tool for treatment of prostate cancer. [ABSTRACT FROM AUTHOR]

Background: Percutaneous injection of bone cement (acrylic cement) during percutaneous kyphoplasty and vertebroplasty can cause symptomatic or asymptomatic complications due to leakage, extravasation or vascular migration of cement. Purpose: To investigate and to compare the incidence and site of local leakage or complications of bone cement after percutaneous kyphoplasty and vertebroplasty using bone cement. Material and Methods: We retrospectively reviewed 473 cases of percutaneous kyphoplasty or vertebroplasty performed under fluoroscopic guidance. Of the 473 cases, follow-up CT scans that covered the treated bones were available for 83 cases (59 kyphoplasty and 24 vertebroplasty). Results: The rate of local leakage of bone cement was 87.5% (21/24) for percutaneous vertebroplasty and 49.2% (29/59) for kyphoplasty. The most common site of local leakage was perivertebral soft tissue (n=8, 38.1%) for vertebroplasty. The most common site of local leakage was a perivertebral vein (n=7, 24.1%) for kyphoplasty. Two cases of pulmonary cement embolism developed: one case after kyphoplasty and one case after vertebroplasty. Conclusion: Local leakage of bone cement was more common for percutaneous vertebroplasty compared with kyphoplasty (P<0.005). The most common sites of local leakage were perivertebral soft tissue and perivertebral vein. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the molecular mechanisms of the antiarthritic effects of bee venom (BV) and melittin (a major component of BV) in a murine macrophage cell line (Raw 264.7) and in synoviocytes obtained from patients with rheumatoid arthritis. METHODS: We evaluated the antiarthritic effects of BV in a rat model of carrageenan-induced acute edema in the paw and in a rat model of chronic adjuvant-induced arthritis. The inhibitory effects of BV and melittin on inflammatory gene expression were measured by Western blotting, and the generation of prostaglandin E(2) (PGE(2)) and nitric oxide (NO) and the intracellular calcium level were assayed. NF-kappaB DNA binding and transcriptional activity were determined by gel mobility shift assay or by luciferase assay. Direct binding of BV and melittin to the p50 subunit of NF-kappaB was determined with a surface plasmon resonance analyzer. RESULTS: BV (0.8 and 1.6 mug/kg) reduced the effects of carrageenan- and adjuvant-induced arthritis. This reducing effect was consistent with the inhibitory effects of BV (0.5, 1, and 5 mug/ml) and melittin (5 and 10 mug/ml) on lipopolysaccharide (LPS; 1 mug/ml)-induced expression of cyclooxygenase 2, cytosolic phospholipase A(2), inducible NO synthase, generation of PGE(2) and NO, and the intracellular calcium level. BV and melittin prevented LPS-induced transcriptional and DNA binding activity of NF-kappaB via the inhibition of IkappaB release and p50 translocation. BV (affinity [K(d)] = 4.6 x 10(-6)M) and melittin (K(d) = 1.2 x 10(-8)M) bound directly to p50. CONCLUSION: Target inactivation of NF-kappaB by directly binding to the p50 subunit is an important mechanism of the antiarthritic effects of BV. [ABSTRACT FROM AUTHOR]