Calpains are Involved in Entamoeba histolytica-Induced Death of HT-29 Colonic Epithelial Cells

Entamoeba histolytica is an enteric tissue-invading protozoan parasite that can cause amebic colitis and liver abscess in humans. E. histolytica has the capability to kill colon epithelial cells in vitro; however, information regarding the role of calpain in colon cell death induced by ameba is limited. In this study, we investigated whether calpains are involved in the E. histolytica-induced cell death of HT-29 colonic epithelial cells. When HT-29 cells were co-incubated with E. histolytica, the propidium iodide stained dead cells markedly increased compared to that in HT-29 cells incubated with medium alone. This pro-death effect induced by ameba was effectively blocked by pretreatment of HT-29 cells with the calpain inhibitor, calpeptin. Moreover, knockdown of m- and µ-calpain by siRNA significantly reduced E. histolytica-induced HT-29 cell death. These results suggest that m- and µ-calpain may be involved in colon epithelial cell death induced by E. histolytica

Magnetic Resonance Imaging Compatibility of the Polymer-based Cochlear Implant

ObjectivesIn this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device.MethodsThe metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment magnets were removed for safety. Magnetic resonance imaging (MRI) was performed on a widely used 3.0 T and an ultra-high 7.0 T MRI machine. 3.0 and 7.0 T MR images were acquired using T1- and T2*-weighted gradient echo sequences, respectively.ResultsIn the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts. The MR images in the proximity of the metal package were obscured by the artifacts in both axial and sagittal views. On the other hand, the MR images near the LCP-based device were relatively free from the artifacts and clearly showed the brain structures. 7.0 T MR images showed the more severe distortion in the both sides but the metal-based cochlear implant system caused a much larger obscure area than the LCP-based system.ConclusionThe novel LCP-based cochlear implant provides a good MRI compatibility beyond present-day cochlear implants. Thus, MR images can be obtained from the subjects even with the implanted LCP-based neural prosthetic systems providing useful diagnostic information. Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging

Effect of Hypoxia-Inducible Factor 1α on Early Healing in Extraction Sockets

The aim of the present study was to investigate the effect of hypoxia-inducible factor 1α (HIF1A) on the early healing (4 weeks) of extraction sockets exhibiting partial loss of the labial bone. Two extraction sockets of the maxillary incisors from each of six dogs were assigned to two treatment modalities: deproteinized bovine bone mineral (i) with 10% collagen (DBBM-C) soaked with HIF1A and covered by a collagen membrane (CM) (HIF group) or (ii) treated with DBBM-C only and covered by a CM (control group). Microcomputed tomography revealed some degree of collapse of the labial contour. The totally augmented volume and new bone volume did not differ significantly between two groups (P>0.05). The histological analysis revealed that the apical area of the socket was mostly filled with newly formed bone, while there was less newly formed bone in the coronal area and incomplete cortex formation. The histomorphometric analysis revealed that the area of newly formed bone was significantly larger in the HIF group than the control group (12.16±3.04 versus 9.48±2.01 mm2, P<0.05), while there was no significant intergroup difference in the total augmented area. In conclusion, even though DBBM-C soaked with HIF1A enhanced histomorphometric bone formation, this intervention did not demonstrate superiority in preventing ridge shrinkage compared to DBBM-C alone. Clinical relevance of these findings should be further studied

Effect of Hypoxia-Inducible Factor 1 on Early Healing in Extraction Sockets

The aim of the present study was to investigate the effect of hypoxia-inducible factor 1 (HIF1A) on the early healing (4 weeks) of extraction sockets exhibiting partial loss of the labial bone. Two extraction sockets of the maxillary incisors from each of six dogs were assigned to two treatment modalities: deproteinized bovine bone mineral (i) with 10% collagen (DBBM-C) soaked with HIF1A and covered by a collagen membrane (CM) (HIF group) or (ii) treated with DBBM-C only and covered by a CM (control group). Microcomputed tomography revealed some degree of collapse of the labial contour. The totally augmented volume and new bone volume did not differ significantly between two groups ( > 0.05). The histological analysis revealed that the apical area of the socket was mostly filled with newly formed bone, while there was less newly formed bone in the coronal area and incomplete cortex formation. The histomorphometric analysis revealed that the area of newly formed bone was significantly larger in the HIF group than the control group (12.16 ± 3.04 versus 9.48 ± 2.01 mm, < 0.05), while there was no significant intergroup difference in the total augmented area. In conclusion, even though DBBM-C soaked with HIF1A enhanced histomorphometric bone formation, this intervention did not demonstrate superiority in preventing ridge shrinkage compared to DBBM-C alone. Clinical relevance of these findings should be further studied

Anti-inflammatory effect of Acalypha australis L. via suppression of NF-kappa B signaling in LPS-stimulated RAW 264.7 macrophages and LPS-induced septic mice

We evaluated the anti-inflammatory activity of methanol extracts of Chinese medicinal plants from Beijing and determined which extract was the most effective. We found the methanol extract of Acalypha auswalis L. (AAL) to be the most effective. AAL has been used for clearing heat, toxic material, and hemostasia in Chinese medicine. Although these uses are closely related to inflammation, the anti-inflammatory effect of AAL has not yet been described and its underlying mechanism remains unclear. Therefore, we aimed to identify anti-inflammatory effect of AAL and its underlying mechanism in vitro and in vivo. In RAW 264.7 macrophages, cytotoxicity was evaluated by MTT assay and nitric oxide (NO) was measured with Griess reagent. To confirm the production of pro-inflammatory cytokines and its mRNA expression, enzyme immunoassay (ETA) and quantitative real-time PCR (qRT-PCR) were performed. Further, protein expression was analyzed by western blotting. Septic shock was induced by intraperitoneal injection of LPS (25 mg/kg) in mice. One hour before LPS injection, AAL (25 and 50 mg/kg) was administered orally. In LPS-stimulated macrophages, AAL inhibited NO production at concentrations without cytotoxicity. Additionally, AAL reduced not only inducible nitric oxide synthase (iNOS) expression but the production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) by attenuating nuclear factor-kappa B (NF-kappa B)-related proteins (NF-kappa B p65, phosphorylation of inhibitor kappa B-alpha; p-I kappa B-alpha, phosphorylation of inhibitor kappa B kinase-alpha/beta; p-Ikk-alpha/beta). Moreover, AAL enhanced the survival rate of mice through the inhibition of iNOS expression and IL-6 and interleukin-1 beta (IL-1 beta) production in LPS-induced septic mice. Furthermore, AAL also reduced the expression of NF-kappa B-related proteins. These finding suggest that AAL is related to the modulation of inflammatory reactions by blocking NF-kappa B activation in LPS-stimulated RAW 264.7 macrophages and LPS-induced septic mice

Critical Role of Northern Off-Equatorial Sea Surface Temperature Forcing Associated with Central Pacific El Nino in More Frequent Tropical Cyclone Movements toward East Asia

Observational records reveal that the number of tropical cyclones (TCs) approaching East Asia in July-October is positively correlated with sea surface temperatures (SSTs) in the equatorial and northern off-equatorial central Pacific (CP) oceans, indicating the significant impact of CP El Nino (CP-EN). Through experiments using a Weather Research and Forecast (WRF) model-based regional climate model, this study demonstrates that it is northern off-equatorial CP warming, rather than equatorial CP warming, that effectively induces local anomalous steering flows pertinent to the observed increase in TC activity over East Asia during CP-EN. Sensitivity experiments, in which the prescribed CP-EN-related SST anomaly is confined near the equator, do not capture the observed TC increase over East Asia, whereas those including the off-equatorial region successfully reproduce observed atmospheric and TC variabilities. The off-equatorial CP SST anomaly acts to expand the anomalous cyclonic response in the Philippine Sea farther northward. This produces a tunnel effect in the East China Sea, by which more TCs move to East Asian coastal regions (e.g., east China, Taiwan, Korea, and Japan).open4