Pharmacological Inhibition of LRRK2 Exhibits Neuroprotective Activity in Mouse Photothrombotic Stroke Model.

Leucine-rich repeat kinase 2 (LRRK2) mutations are the most common cause of Parkinson's disease (PD). Interestingly, recent studies have reported an increased risk of stroke in patients with PD harboring LRRK2 mutations, but there is no evidence showing the functional involvement of LRRK2 in stroke. Here, we found that LRRK2 kinase activity was significantly induced in the Rose-Bengal (RB) photothrombosis-induced stroke mouse model. Interestingly, stroke infarct volumes were significantly reduced, and neurological deficits were diminished by pharmacological inhibition of LRRK2 kinase activity using MLi-2, a brain-penetrant LRRK2 kinase inhibitor. Immunohistochemical analysis showed p-LRRK2 level in stroke lesions, co-localizing with mitophagy-related proteins (PINK, Parkin, LC3B, cytochrome c), suggesting their involvement in stroke progression. Overlapping p-LRRK2 with cytochrome c/TUNEL/JC-1 (an indicator of mitochondrial membrane potential) puncta in RB photothrombosis indicated LRRK2-induced mitochondrial apoptosis, which was blocked by MLi-2. These results suggest that pharmacological inhibition of LRRK2 kinase activity could attenuate mitochondrial apoptosis, ultimately leading to neuroprotective potential in stroke progression. In conclusion, LRRK2 kinase activity might be neuro-pathogenic due to impaired mitophagy in stroke progression, and pharmacological inhibition of LRRK2 kinase activity could be beneficial in reducing the risk of stroke in patients with LRRK2 mutations.

Identifying Small Bowel Gastrointestinal Stromal Tumor as the Culprit Lesion in Obscure Gastrointestinal Bleeding: Emphasis on Angiographic Findings.

Gastrointestinal stromal tumors (GISTs) are not uncommon and often cause gastrointestinal bleeding. GISTs occurring in the small intestine are occasionally difficult to identify by endoscopy and CT. In this case, the patient underwent CT three times before surgery, and the lesion was found to be located in a different area of the abdominal cavity on each CT scan. Moreover, the lesion was missed in the first two CT images because it was difficult to distinguish it from the nearby collapsed small intestine. The lesion was eventually detected through angiography; however, the correct diagnosis and treatment were delayed for 3 years because it was mistaken for a vascular malformation, which is the most common cause of obscure GI bleeding in elderly patients. This report emphasizes the need for interventional radiologists to be updated and vigilant of the angiographic features of GISTs to make an accurate diagnosis and establish a management strategy.

High grade carcinoma ex pleomorphic adenoma of parotid gland: a case report.

Pleomorphic adenoma is the most prevalent benign tumor of the parotid gland, and shows potential malignancy. Carcinoma ex pleomorphic adenoma (CXPA) can occur in 3%-15% of pleomorphic adenoma cases. Owing to its clinical similarity to benign tumors, critical information related to CXPA can be easily overlooked, leading to frequent misdiagnosis of the condition. In this article, we report a rare case of CXPA found in the 55-year-old male patient with characteristic clinical, radiographic, and histological features, and subsequent treatment.

[A Case of Isolated Leptomeningeal Carcinomatosis from Advanced Gastric Cancer].

Leptomeningeal carcinomatosis (LMC) is rare metastatic form of gastric cancer. Most cases are diagnosed in the final stage after multiple distant metastasis. An 84-year-old woman was admitted with melena, headache and vomiting. Esophagogastroduodenoscopy showed an ulceroinfiltrating lesion at the stomach (Borrmann class III), and biopsy revealed a signet ring cell carcinoma. The abdominal-pelvic CT showed no evidence of metastasis. A sudden decrease of consciousness was noted, but the brain CT showed no active lesion while the brain MRI revealed enhancement of leptomeninges. A lumbar puncture was performed and the cerebrospinal fluid study revealed malignant neoplastic cells. With family consent, no further evaluation and treatment were administered and she died six weeks after the diagnosis of gastric cancer. We report an extremely rare case of a patient who initially presented with neurologic symptoms, and was diagnosed LMC from advanced gastric cancer without any evidence of metastasis in abdomen and pelvis.

Findings from frozen sections of spinal subependymomas: Is it possible to differentiate this diagnosis from other common spinal tumors?

Subependymomas are slow-growing, benign neoplasms that are rarely found in the spinal cord. Because of the differences in the treatment plans, it might be very helpful for neurosurgeons to intraoperatively establish a diagnosis of spinal subependymoma, differentiated from other spinal intramedullary tumors. In this study, we analyzed frozen sections of spinal subependymomas to identify potential histological clues of spinal subependymomas to differentiate them from tumors that mimic spinal subependymoma. We reviewed the frozen sections and the corresponding permanent slides for 7 cases of spinal subependymoma. The spinal subependymomas showed several characteristic patterns, including, most importantly, an eccentric or both central and eccentric location in the axial plane. Histologically, they showed a (1) well-demarcated and multinodular mass with (2) low or moderate cellularity, (3) a microlobular pattern, and (4) small clusters of neoplastic cells. These features appear to be very specific to spinal subependymomas and could help differentiate them from ependymomas or astrocytomas. Although we might not be able to provide an exact diagnosis of all spinal subependymomas using these histological features, we hope that they help neuropathologists and neurosurgeons to adequately diagnose and treat spinal subependymomas.

Impact of NRAS Mutations on the Diagnosis of Follicular Neoplasm of the Thyroid.

Background. Most patients with a preoperative diagnosis of thyroid follicular neoplasm (FN) undergo diagnostic surgery to determine whether the nodule is benign or malignant. Point mutations at NRAS codon 61 are the most common mutations observed in FN. However, the clinical significance of NRAS mutation remains unclear. Methods. From 2012 to 2013, 123 consecutive patients undergoing thyroidectomy for FN were evaluated prospectively. Molecular analyses for NRAS codon 61 were performed with pyrosequencing. Results. The overall malignancy rate in FN was 48.8% (60/123). Of 123 FNs, 33 (26.8%) were positive for the NRAS mutation. The sensitivity, specificity, positive predictive value, and negative predictive value of a NRAS mutation-positive FN specimen to predict malignancy were 37%, 83%, 67%, and 58%, respectively. Patients with a NRAS-positive FN had a higher malignancy rate in additional thyroid nodules beyond the FN than patients with a NRAS-negative FN. The overall malignancy rate of patients with a NRAS-positive FN was significantly higher than that of patients with a NRAS-negative FN (79% versus 52%; P = 0.008). Conclusions. Determining NRAS mutation status in FN helps to improve the accuracy of thyroid cancer diagnosis and to predict cancer risk in accompanying thyroid nodules.

Overexpression of DJ-1 and HSP90α, and loss of PTEN associated with invasive urothelial carcinoma of urinary bladder: Possible prognostic markers.

DJ-1 and HSP90α play a significant role in the progression of various types of cancer and are known to be associated with phosphatase and tensin homolog deleted on chromosome 10 (PTEN), PI3K-p110α and pAkt, the signaling molecule proteins from the phosphatidylinositol 3-kinase (PI3K) pathway. However, the expression of these proteins and their clinical significance are not well characterized in urothelial carcinoma (UC). Immunohistochemical analysis of DJ-1, HSP90α, PTEN, pAkt and PI3K-p110α expression was performed on tumor samples from 102 patients with UC to assess the relationship between the expression of each protein and the pathological parameters. The expression of DJ-1 and HSP90α was positively correlated with the pathological stage of UC, whereas PTEN expression negatively correlated with, not only the pathological stage, but also the growth pattern and histological grade of UC. Although PI3K-p110α expression was significantly correlated with DJ-1 as well as PTEN expression in UC, PI3K-p110α expression itself failed to reveal any significant correlation with the clinicopathological parameters. In conclusion, the overexpression of DJ-1 and HSP90α, and a loss of PTEN are associated with invasive UC, and PI3K-p110α expression is correlated with DJ-1 and PTEN expression in UC.

Effect of fluorescent whitening agent on the transcription of cell damage-related genes in zebrafish embryos.

7-Diethylamino-4-methylcoumarin (DEMC) is a fluorescent whitening agent (FWAs). There have been some studies on DEMC's protective effects against biological activity but there are few papers about the in vivo toxicity of DEMC. In this study, we used wild-type zebrafish embryos 3 days post fertilization (dpf). Test solutions with DEMC concentrations were negative control (without vehicle), 0 (with vehicle, 0.01% v/v ethanol), 0.25, 0.5, 0.75, 1.0, 1.25, 1.5 and 2 ppm. Embryos and larvae were counted for survival rate and hatching rate. Heart rates were also counted at 2.5 and 3.0 dpf. At 3.0 dpf, quantitative RT-PCR was performed with some samples (0, 0.25, 0.75 and 1.25 ppm) to determine the toxic effect to DEMC by detecting the expression levels of toxic-responsive genes. We used 11 genes, which included oxidative stress-related genes [sod(Mn), sod(Cu,Zn) and hsp70], mitochondrial metabolism-related genes (coxI, pyc, cyt and cyclinG1) and apoptosis-related genes (c-jun, bcl2, bax and p53). High-concentration DEMC-treated groups showed significant different survival rate, hatching rate and heart rate compared with low-concentration DEMC-treated groups. The LC50 of this chemical, 0.959 ppm, was calculated. We also confirmed that some genes in the DEMC exposure groups showed significantly up-regulations in expression levels compared with control groups. We concluded that the fluorescence agent, DEMC, has possible developmental toxicities and alteration effect of gene expression, which are related to oxidative stress, mitochondrial metabolism and apoptosis in zebrafish embryos.

Low-temperature growth of ZnO nanorods by chemical bath deposition.

Aligned ZnO nanorod arrays were synthesized using a chemical bath deposition method at normal atmospheric pressure without any metal catalyst. A simple two-step process was developed for growing ZnO nanorods on a PET substrate at 90-95 degrees C. The ZnO seed precursor was prepared by a sol-gel reaction. ZnO nanorod arrays were fabricated on ZnO-seed-coated substrate. The ZnO seeds were indispensable for the aligned growth of ZnO nanorods. The ZnO nanorods had a length of 400-500 nm and a diameter of 25-50 nm. HR-TEM and XRD analysis confirmed that the ZnO nanorod is a single crystal with a wurtzite structure and its growth direction is [0001] (the c-axis). Photoluminescence measurements of ZnO nanorods revealed an intense ultraviolet peak at 378.3 nm (3.27 eV) at room temperature.

Real-time measurement of the contractile forces of self-organized cardiomyocytes on hybrid biopolymer microcantilevers.

We present a microfabricated hybrid biopolymer microcantilever, in which the contractile force of self-organized cardiomyocytes can be measured and studied, as a prototype for the development of cell-driven actuators. The microcantilever is made of a flexible, transparent, biocompatible poly(dimethylsiloxane) substrate, using a simple microfabrication technique. Seeding and culturing cardiomyocytes on the specific cantilever allows us to perform highly sensitive, quantitative, and noninvasive measurement of the contractile force of the self-organized cells in real time. The motions of the microcantilever showed good agreement with an analytical solution based on Stoney's equation and finite element modeling (FEM) of the hybrid system. Immunostaining of the cells on the hybrid system showed continuous high-order coalignment of actin filaments and parallel sarcomeric organization in the direction of the longitudinal axis of the microcantilever without structural constraints, such as microgrooves or lines, and proved our FEM and the synchronous contraction of cardiomyocytes. The presented device should facilitate measurement of the contractile force of self-organized cardiomyocytes on a specific area, which may help the understanding of heart failure and the design of optimal hybrid biopolymer actuators, as well as assist development of a microscale cell-driven motor system.

An efficient cell separation system using 3D-asymmetric microelectrodes.

An efficient 3D-asymmetric microelectrode system for high-throughput was designed and fabricated to enhance sorting sensitivities to the dielectric properties-size, morphology, conductivity, and permittivity-of living cells. The principle of the present system is based on the use of the relative strengths of negative dielectrophoretic and drag forces, as in a conventional 3D-microelectrode system. Whereas the typical 3D-microelectrode system has a constant electric field magnitude due to the constant width of the microelectrodes and a fixed gap between face-to-face microelectrodes, the present 3D-asymmetric microelectrode system has electric fields of continuously varying magnitudes along the transverse direction of a channel owing to the changing widths of the electrodes in the half-circular shaped cross section of the microchannel. Thus, varying dielectric forces are generated, leading to increased sorting sensitivity through differentially induced forces to definitely distinct cell types. Numerical analysis verified the improved sensitivity of the present system for sorting living cells. The feasibility of using the newly fabricated system under experimental conditions was tested by demonstrating that a mixed population of mouse P19 embryonic carcinoma (EC) and red blood cells (RBCs) was effectively sorted to different wells depending on their respective relative physical properties.

Nucleoside-based phospholipids and their liposomes formed in water.

Phospholipids and liposomes have been the subjects of considerable attention because of their importance in biological systems. We have efficiently synthesized novel nucleoside-based phospholipids in six-step sequences starting from their corresponding nucleosides. These nucleoside-based phospholipids self-assemble into liposome-like structures in aqueous solutions. We have analyzed the structures of these liposomes by dynamic light scattering, transmission electron microscopy, and confocal microscopy.