Producing xylan/Eudragit® S100-based microparticles by chemical and physico-mechanical approaches as carriers for 5-aminosalicylic acid.

Xylan is a biopolymer found in a variety of cell wall plants. Eudragit® S-100 (ES100), a pH-dependent polymer, is used as a coating material in gastroresistant delivery systems. In this study, microparticles based on both polymers were produced by interfacial cross-linking polymerisation and/or spray-drying technique in order to investigate feasibility and stability of the systems. Size and morphology of the microparticles were characterised by optical and SEM while FT-IR, thermal analysis (TG/DTA), and X-ray diffraction (XRD) evaluated the drug-polymer interactions and the thermal behaviour of the systems. FT-IR confirmed the absence of chemical interaction between the polymers. TG/DTA analysis showed a higher stability for spray-dried microparticles and XRD data proved the amorphous feature of both carriers. The results reveal that xylan/ES100 microparticles can be produced by chemical or physico-mechanical ways, the latter being the best option due to the lack of toxic cross-linking agents and easy scale-up.

Staging primary head and neck cancers with (18)F-FDG PET/CT: is intravenous contrast administration really necessary?

PURPOSE: The aim of our study was to prospectively evaluate whether intravenous contrast media in integrated positron emission tomography and computed tomography (PET/CT) with (18)F-fluorodeoxyglucose ((18)F-FDG) significantly contributes to evaluation of primary head and neck cancers compared with unenhanced PET/CT, regional contrast-enhanced CT of head and neck (neck CE-CT) and regional magnetic resonance imaging of head and neck (neck MRI). METHODS: Subjects were 42 consecutive patients (35 men, 7 women; age range: 36-91 years) with biopsy-proven primary head and neck cancers. Lesion detection of primary and nodal sites and TNM classification were assessed on a per-patient basis. McNemar test and kappa statistics were employed for statistical analyses. RESULTS: Forty patients (95%) were successfully followed up: 24 patients had nodal disease and 3 had distant metastasis. Contrast-enhanced and unenhanced PET/CT detected 98 and 95% of the primary tumours, respectively, and both detected 92% of patients with nodal disease, which revealed no statistically significant difference. Accuracy for T status was 75 and 73%, respectively, which proved significantly more accurate than neck CE-CT, which had an accuracy of 53% (p = 0.0133 and 0.0233, respectively). Neck MRI correctly classified the T status in 58% of patients; however, no statistically significant difference was found between PET/CT and neck MRI. Contrast-enhanced PET/CT, unenhanced PET/CT, neck CT and neck MRI correctly staged the N status in 90, 90, 79 and 90% of patients, respectively, with no statistically significant difference. Overall TNM classification was correctly classified in 68 and 65% of patients, respectively. Weighted kappa values between enhanced and unenhanced PET/CT for primary tumour detection, nodal detection, T status and N status were 0.655, 1.000, 0.935 and 1.000, respectively. CONCLUSION: We found almost perfect correlation between enhanced and unenhanced PET/CT for lesion detection and initial staging of primary head and neck cancers. Routine contrast administration for PET/CT imaging may not be justified.

Right double inferior vena cava: Report of 5 cases and literature review.

OBJECTIVE: To describe the computed tomography appearance, embryology, and clinical implications of right double inferior vena cava (IVC). METHODS: Computed tomography imaging findings were retrospectively reviewed in our 5 patients and in 2 cases reported in the literature with right double IVC. The relationship of the 2 postrenal IVCs, their diameter, level of confluence of the 2 IVCs, course of the left common iliac vein, draining site of the right gonadal vein, and the presence of retrocaval ureter were evaluated. RESULTS: In all cases, the relationship of 2 IVCs was ventral-dorsal, and the left common iliac vein passed ventral to the aortic bifurcation or the right common iliac artery. The relationship of the diameters and level of confluence of the 2 IVCs were variable. The right gonadal vein drained into the ventral vessel in 4 cases and into the IVC between the renal venous confluence and the confluence of the 2 vessels in 1 case. In all cases, the retrocaval ureter was not identified. CONCLUSIONS: Characteristic computed tomography findings of right double IVC were a ventral-dorsal relationship between the 2 vessels and the unusual course of the left common iliac vein. Embryologically, the ventral vessel originates from the right subcardinal vein, whereas the dorsal vessel originates from the right supracardinal vein. Although this anomaly is extremely rare, radiologists should recognize it.