Small Lesions Evaluation Based on Unsupervised Cluster Analysis of Signal-Intensity Time Courses in Dynamic Breast MRI

An application of an unsupervised neural network-based computer-aided diagnosis (CAD) system is reported for the detection and characterization of small indeterminate breast lesions, average size 1.1 mm, in dynamic contrast-enhanced MRI. This system enables the extraction of spatial and temporal features of dynamic MRI data and additionally provides a segmentation with regard to identification and regional subclassification of pathological breast tissue lesions. Lesions with an initial contrast enhancement ≥50% were selected with semiautomatic segmentation. This conventional segmentation analysis is based on the mean initial signal increase and postinitial course of all voxels included in the lesion. In this paper, we compare the conventional segmentation analysis with unsupervised classification for the evaluation of signal intensity time courses for the differential diagnosis of enhancing lesions in breast MRI. The results suggest that the computerized analysis system based on unsupervised clustering has the potential to increase the diagnostic accuracy of MRI mammography for small lesions and can be used as a basis for computer-aided diagnosis of breast cancer with MR mammography

Long-Term Prognosis of Patients With Takotsubo Syndrome

BACKGROUND Prognosis of Takotsubo syndrome (TTS) remains controversial due to scarcity of available data. Additionally, the effect of the triggering factors remains elusive. OBJECTIVES This study compared prognosis between TTS and acute coronary syndrome (ACS) patients and investigated short- and long-term outcomes in TTS based on different triggers. METHODS Patients with TTS were enrolled from the International Takotsubo Registry. Long-term mortality of patients with TTS was compared to an age- and sex-matched cohort of patients with ACS. In addition, short- and long-term outcomes were compared between different groups according to triggering conditions. RESULTS Overall, TTS patients had a comparable long-term mortality risk with ACS patients. Of 1,613 TTS patients, an emotional trigger was detected in 485 patients (30%). Of 630 patients (39%) related to physical triggers, 98 patients (6%) had acute neurologic disorders, while in the other 532 patients (33%), physical activities, medical conditions, or procedures were the triggering conditions. The remaining 498 patients (31%) had no identifiable trigger. TTS patients related to physical stress showed higher mortality rates than ACS patients during long-term follow-up, whereas patients related to emotional stress had better outcomes compared with ACS patients. CONCLUSIONS Overall, TTS patients had long-term outcomes comparable to age- and sex-matched ACS patients. Also, we demonstrated that TTS can either be benign or a life-threating condition depending on the inciting stress factor. We propose a new classification based on triggers, which can serve as a clinical tool to predict short- and long-term outcomes of TTS. (International Takotsubo Registry [InterTAK Registry]; NCT01947621)

Routine MRI findings of the asymptomatic foot in diabetic patients with unilateral Charcot foot

<p>Abstract</p> <p>Background</p> <p>Imaging studies of bones in patients with sensory deficits are scarce.</p> <p>Aim</p> <p>To investigate bone MR images of the lower limb in diabetic patients with severe sensory polyneuropathy, and in control subjects without sensory deficits.</p> <p>Methods</p> <p>Routine T1 weighted and T2-fat-suppressed-STIR-sequences without contrast media were performed of the asymptomatic foot in 10 diabetic patients with polyneuropathy and unilateral inactive Charcot foot, and in 10 matched and 10 younger, non-obese unmatched control subjects. Simultaneously, a Gadolinium containing phantom was also assessed for reference. T1 weighted signal intensity (SI) was recorded at representative regions of interest at the peritendineal soft tissue, the tibia, the calcaneus, and at the phantom. Any abnormal skeletal morphology was also recorded.</p> <p>Results</p> <p>Mean SI at the soft tissue, the calcaneus, and the tibia, respectively, was 105%, 105% and 84% of that at the phantom in the matched and unmatched control subjects, compared to 102% (soft tissue), 112% (calcaneus) and 64% (tibia) in the patients; differences of tibia vs. calcaneus or soft tissue were highly significant (p < 0.005). SI at the tibia was lower in the patients than in control subjects (p < 0.05). Occult traumatic skeletal lesions were found in 8 of the 10 asymptomatic diabetic feet (none in the control feet).</p> <p>Conclusion</p> <p>MR imaging did not reveal grossly abnormal bone marrow signalling in the limbs with severe sensory polyneuropathy, but occult sequelae of previous traumatic injuries.</p

Enzyme-Nanoporous Gold Biocomposite: Excellent Biocatalyst with Improved Biocatalytic Performance and Stability

Background: Applications involving biomolecules, such as enzymes, antibodies, and other proteins as well as whole cells, are often hampered by their unstable nature at extremely high temperature and in organic solvents. Methodology/Principal Findings: We constructed enzyme-NPG biocomposites by assembling various enzymes onto the surface of nanoporous gold (NPG), which showed much enhanced biocatalytic performance and stability. Various enzymes with different molecular sizes were successfully tethered onto NPG, and the loadings were 3.6, 3.1 and 0.8 mg g 21 for lipase, catalase and horseradish peroxidase, respectively. The enzyme-NPG biocomposites exhibited remarkable catalytic activities which were fully comparable to those of free enzymes. They also presented enhanced stability, with 74, 78 and 53 % of enzymatic activity retained after 20 successive batch reactions. Moreover, these novel biocomposites possessed significantly enhanced reaction durability under various thermal and in organic solvent systems. In a sample transesterification reaction, a high conversion rate was readily achieved by using the lipase-NPG biocomposite. Conclusion/Significance: These nano-biocomposite materials hold great potential in applications such as biosensing, molecular electronics, catalysis, and controlled delivery

Polymer Composites Containing Gated Mesoporous Materials for On-Command Controlled Release

Polyamidic nanofibrous membranes containing gated silica mesoporous particles, acting as carriers, are described as novel hybrid composite materials for encapsulation and on-command delivery of garlic extracts. The carrier system consists of MCM-41 solids functionalized in the outer surface, with linear polyamines (solid P1) and with hydrolyzed starch (solid P2), both acting as molecular gates. Those particles were adsorbed on electospun nylon-6 nanofibrous membranes yielding to composite materials M1 and M2. FE-SEM analysis confirmed the presence of particles incorporated on the nylon nanofibers. The release of the entrapped molecules (garlic extract) from the P1, P2, M1, and M2 materials was evaluated using cyclic voltammetry measurements. Electrochemical studies showed that at acidic pH P1 and M1 were unable to release their entrapped cargo (closed gate), whereas at neutral pH both materials release their loading (open gate). Dealing with P2 and M2 materials, in the absence of pancreatin a negligible release is observed (closed gate), whereas in the presence of enzyme the load is freely to diffuse to the solution. These newly developed composite nanomaterials, provide a homogeneous easy-to-handle system with controlled delivery and bioactive-protective features, having potential applications on pharmacology, medical and engineering fields.The authors wish to express their gratitude to the Generalitat Valenciana (Grisolia scholarship 2011/012, project PROM-ETEO/2009/016), Spanish Government (MINECO Projects AGL2012-39597-C02-01, AGL2012-39597-C02-02 and MAT2012-38429-C04-01) and the CIBER-BBN for their support. IILA thanks DISTAM and Universita degli di Milano for a specialization scholarship. We would also like to thank the Institut de Ciencia dels Materials (ICMUV) and to the Microscopy Service of the Universitat Politecnica de Valencia for technical support. We thank Roquette for the Glucidex samples.Acosta Romero, C.; Pérez Esteve, E.; Fuenmayor, CA.; Benedetti, S.; Cosio, MS.; Soto Camino, J.; Sancenón Galarza, F.... (2014). Polymer Composites Containing Gated Mesoporous Materials for On-Command Controlled Release. ACS Applied Materials and Interfaces. 6(9):6453-6460. https://doi.org/10.1021/am405939y645364606

Delivery modulation in silica mesoporous supports via alkyl chain pore outlet decoration

This article focuses on the study of the release rate in a family of modified silica mesoporous supports. A collection of solids containing ethyl, butyl, hexyl, octyl, decyl, octadecyl, docosyl, and triacontyl groups anchored on the pore outlets of mesoporous MCM-41 has been prepared and characterized. Controlled release from pore voids has been studied through the delivery of the dye complex tris(2,2¿-bipyridyl)ruthenium(II). Delivery rates were found to be dependent on the alkyl chain length anchored on the pore outlets of the mesoporous scaffolding. Moreover, release rates follow a Higuchi diffusion model, and Higuchi constants for the different hybrid solids have been calculated. A decrease of the Higuchi constants was observed as the alkyl chain used to tune the release profile is longer, confirming the effect that the different alkyl chains anchored into the pore mouths exerted on the delivery of the cargo. Furthermore, to better understand the relation between pore outlets decoration and release rate, studies using molecular dynamics simulations employing force-field methods have been carried out. A good agreement between the calculations and the experimental observations was observed.Financial support from the Spanish Government (projects MAT2009-14564-C04-01 and MAT2009-14564-C04-04) and the Generalitat Valencia (project PROMETEO/2009/016) is gratefully acknowledged.Aznar Gimeno, E.; Sancenón Galarza, F.; Marcos Martínez, MD.; Martínez Mañez, R.; Stroeve, P.; Cano, J.; Amoros Del Toro, P. (2012). Delivery modulation in silica mesoporous supports via alkyl chain pore outlet decoration. Langmuir. 28:2986-2996. https://doi.org/10.1021/la204438jS298629962