Double-helical DNA was used as a template for the assembly of helical cyanine dye aggregates. The aggregates consist of cofacial dimers aligned end-to-end in the minor groove of the DNA. The effect of methoxy or fluoro substituents placed on the periphery of the cyanine dye heterocycles on aggregation both in water and on the DNA template was studied by UV-vis and circular dichroism spectroscopy. Methoxy groups were found to be stronger promoters of aggregation than fluoro, and a dimethoxy dye exhibited a higher propensity to aggregate compared with an unsymmetrical methoxy/fluoro dye. Semiempirical calculations supported the experimental observation of methoxy substitution favoring aggregation. These results indicate that dispersion and hydrophobic effects contribute more to dimerization/aggregation than do electron donor-acceptor effects.
ObjectivesPineal lesions can present as a heterogeneous collection of benign and malignant disease conditions. Pineal lesions include germ cell tumours, neoplasms arising from the pineal parenchyma, as well as other pineal region masses.MethodsA variety of cases of pineal lesions are presented. The important clinical features and typical imaging findings of each pineal lesion are described with emphasis on their morphological appearance and signal intensity characteristics on magnetic resonance imaging (MRI).ConclusionKnowledge of the imaging characteristics and clinical features of varying pineal lesions can assist in narrowing the differential diagnosis for more accurate and rational therapeutic planning.Teaching Points• Pineal parenchymal tumours show an “explosion” of normal pineal calcifications towards the periphery.• Pineoblastomas often have restricted diffusion, with apparent diffusion coefficient (ADC) values lower than germinomas.• Pineal teratomas and pineal lipomas display fat signal characteristics and fat saturation on MRI.• Pineal lesions in patients with known malignancy should raise suspicion of metastatic involvement.• Pineal cysts and arachnoid cysts show MRI signal characteristics similar to cerebrospinal fluid (CSF).
Purpose: To evaluate the efficacy of prostate artery embolization (PAE) for the treatment of benign prostatic hyperplasia (BPH) for prostates 80 g. Materials: Patient demographics, International Prostate Symptom Score (IPSS), Quality of Life score (QOL), prostate volume assessed by MRI, maximum urinary flow (Qmax), and post-void residual (PVR) volume were evaluated as part of an IRB-approved retrospective analysis at a single institution. Exclusion criteria included patients with active urinary tract infection, renal failure, or severe atherosclerosis. Results: Between January 2014 and September 2017, 110 patients underwent PAE for BPH with prostate size 80 g. Mean patient age was 69.0 years, mean baseline QOL was 4.7, and mean prostate volume was 153.7 g. At 1, 3, 6, and 12 months, QOL score improved to 1.6, 1.0, 0.9, and 1.1, respectively (p<0.001 for all). At 3 and 12 months of follow-up, mean prostate volume had decreased to 105.4g (p<0.001) and 96.1g (p<0.001). Among the 85 (77.3%) patients non-reliant on bladder catheterization prior to
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