Is There Pathological Uniformity between the Periphery and Center of a Gastrointestinal Stromal Tumor?

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors and have some malignant potential. Mitotic count is important for predicting the malignant potential of GISTs. Proper treatment of GISTs requires accurate pathological diagnosis. In general, endoscopic ultrasound-guided fine-needle aspiration and deep biopsy are used for pathological diagnosis of GIST before making decisions about surgery. This study sought to evaluate the pathological uniformity of gastric GISTs for mitotic index of the center and periphery of the GIST. METHODS: We retrospectively reviewed the data of 37 gastric GIST patients who underwent wedge resection at Hanyang University Hospital. We used Armed Forces Institute of Pathology criteria to classify gastric GISTs. To determine the pathological uniformity of gastric GISTs, we compared GIST risk stratification between the center and periphery of GISTs. RESULTS: The mean size of GISTs was 3.56 ± 2.10 cm. Three lesions were located in the antrum, 11 in the fundus, 9 in the cardia, and 14 in the body. The mean age of patients was 58.65 ± 9.44 years; 18 patients were male and 19 were female. Thirty-five patients (94.6%) showed the same level of risk stratification between the center and periphery of gastric GISTs, while two patients (5.4%) presented different levels of risk between the two sites. No significant difference in mitotic count was observed between the two sites (kappa value = 0.863; p = 0.001). CONCLUSIONS: Mitotic index category (either more than five mitoses per high-power field or five or fewer mitoses per high-power field) of GISTs showed good concurrence between the center and periphery.

Effective delivery of immunosuppressive drug molecules by silica coated iron oxide nanoparticles.

Iron oxide nanoparticles have been used in a wide range of biomedical applications, including drug delivery, molecular imaging, and cellular imaging. Various surface modifications have been applied to the particles to stabilize their surface and to give them a moiety for anchoring tags and/or drug molecules. Conventional methods of delivering immunosuppressant drugs often require a high dose of drugs to ensure therapeutic effects, but this can lead to toxic side effects. In this study, we used silica-coated iron oxide nanoparticles (IOSs) for a drug delivery application in which the nanoparticles carry the minimum amount of drug required to be effective to the target cells. IOSs could be loaded with water-insoluble immunosuppressive drug molecules (MPA: mycophenolic acid) and be used as a contrast agent for MRI. We characterized the IOSs for their physicochemical properties and found their average hydrodynamic diameter and core size to be 40.5nm and 5nm, respectively. Following the introduction of MPA-loaded IOSs (IOS/M), we evaluated the secretion dynamics of cytokines from peripheral blood mononuclear cells stimulated with phytohemagglutinin (PHA). The results showed that IOS/M effectively inhibited the secretion of the cytokines interleukin-2 and tumor necrosis factor α, with a minimal concentration of MPA. In conclusion, IOS/M may have potential applications in both efficient drug delivery and MRI.

Engineered nanoconstructs for the multiplexed and sensitive detection of high-risk pathogens.

Many countries categorize the causative agents of severe infectious diseases as high-risk pathogens. Given their extreme infectivity and potential to be used as biological weapons, a rapid and sensitive method for detection of high-risk pathogens (e.g., Bacillus anthracis, Francisella tularensis, Yersinia pestis, and Vaccinia virus) is highly desirable. Here, we report the construction of a novel detection platform comprising two units: (1) magnetic beads separately conjugated with multiple capturing antibodies against four different high-risk pathogens for simple and rapid isolation, and (2) genetically engineered apoferritin nanoparticles conjugated with multiple quantum dots and detection antibodies against four different high-risk pathogens for signal amplification. For each high-risk pathogen, we demonstrated at least 10-fold increase in sensitivity compared to traditional lateral flow devices that utilize enzyme-based detection methods. Multiplexed detection of high-risk pathogens in a sample was also successful by using the nanoconstructs harboring the dye molecules with fluorescence at different wavelengths. We ultimately envision the use of this novel nanoprobe detection platform in future applications that require highly sensitive on-site detection of high-risk pathogens.

Enhanced detection of single-cell-secreted proteins using a fluorescent immunoassay on the protein-G-terminated glass substrate.

We present an evaluation of protein-G-terminated glass slides that may contain a suitable substrate for aligning the orientation of antibodies to obtain better binding moiety to the target antigen. The results of the protein-G-terminated slides were compared with those obtained with epoxy-based slides to evaluate signal enhancement for human immunoglobulin G (IgG) targets, and an increase in the average fluorescence intensity was observed for the lowest measurable amount of IgG target in the assay using protein-G-terminated slides. Applying this strategy for signal amplification to single-cell assays improves the limits of detection for human IgG protein and cytokines (interleukin-2 and interferon-γ) captured from hybridomas. Our data indicate that protein-G-terminated slides have a higher binding capacity for antigens and have better spot-to-spot consistency than that of traditional epoxy-based slides. These properties would be beneficial in the detection of fine amounts of single-cell-secreted proteins, which may provide key insights into cell-cell communication and immune responses.

Biomimetics: forecasting the future of science, engineering, and medicine.

Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark's skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations.