ABSTRACT
Antioxidant enzymes for the treatment of oxidative stress-related diseases remain a highly promising therapeutic approach. As poor localization and stability have been the greatest challenges to their clinical translation, a variety of nanocarrier systems have been developed to directly address these limitations. In most cases, there has been a trade-off between the delivered mass of enzyme loaded and the carrier's ability to protect the enzyme from proteolytic degradation. One potential method of overcoming this limitation is the use of ordered mesoporous silica materials as potential antioxidant enzyme nanocarriers. The present study compared the loading, activity and retention activity of an anti-oxidant enzyme, catalase, on four engineered mesoporous silica types: non-porous silica particles, spherical silica particles with radially oriented pores and hollow spherical silica particles with pores oriented either parallel to the hollow core or expanded, interconnected bimodal pores. All these silica types, except non-porous silica, displayed potential for effective catalase loading and protection against the proteolytic enzyme, pronase. Hollow particles with interconnected pores exhibit protein loading of up to 50 wt.% carrier mass, while still maintaining significant protection against proteolysis.
Subject(s)
Antioxidants/administration & dosage , Catalase/administration & dosage , Drug Carriers , Nanoparticles , Silicon Dioxide/chemistry , Catalase/metabolism , Microscopy, Electron, Scanning , Proteolysis , Spectrophotometry, UltravioletABSTRACT
Hyperintensities on T1-weighted magnetic resonance imaging (MRI) in the setting of brain ischemia are usually considered hemorrhagic transformations. Such changes can also be seen due to "incomplete infarction" with selective neuronal loss. Arguments regarding the cause of these T1 hyperintensities have shuttled between gemistocytic astrocyte accumulation, tissue calcification and paramagnetic substance deposition. Susceptibility weighted imaging (SWI), a sensitive modality for detecting paramagnetic agents and blood products, has never been used to resolve this issue. The study was aimed to evaluate the SWI signal changes of T1 hyperintense lesion in stroke patients and understand its usefulness in differentiating a hemorrhagic infarct and an incomplete infarct. All the seven patients with infarct, having hyperintensities on T1 weighted MR imaging seen over the last one year were subjected to SWI. In none of the patients SWI failed to show any blooming. By doing SWI for T1-weighted hyperintensities, we can differentiate hemorrhagic infarct and a non-hemorrhagic "incomplete infarct". This differentiation will immensely help in planning management strategy and prognostication.
Subject(s)
Disease Susceptibility , Magnetic Resonance Imaging/methods , Stroke/pathology , Child , Female , Humans , Image Processing, Computer-Assisted/methods , Male , Middle Aged , Stroke/diagnostic imaging , Time Factors , Tomography, X-Ray Computed/methodsABSTRACT
Papillon Lefèvre syndrome is a rare disease characterized by skin lesions caused by palmar-plantar hyperkeratosis, and severe periodontal destruction involving both the primary and permanent dentitions. It is transmitted as an autosomal recessive condition and consanguinity of parents is evident in about one-third of cases. Pyogenic liver abscess is an increasingly recognized complication. We report a new case of this association and review the current literature.
