Mammalian cell is critically dependent on a continuous supply of oxygen. Even brief periods of oxygen deprivation can result in profound cellular damage. The aim of this study was to examine the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3E1 osteoblasts under hypoxic conditions (2% oxygen) resulted in apoptosis in a time-dependent manner, determined by DNA fragmentation assay and nuclear morphology, stained with fluorescent dye (Hoechst 33258) Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, suppressed the DNA ladder in response to hypoxia in a concentration-dependent manner. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases were involved in apoptosis, western blot analysis was performed using an anti-caspase-3 or 6 antibody. The 17-kDa protein, that corresponds to the active products of caspase-3 and the 20-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged lysates, in which the full length forms of caspase-3 and 6 were evident. With a time course similar to caspase-3 and 6 activation, hypoxic stress also caused the cleavage of Lamin A, typical of caspase-6 activity. In addition, the hypoxic stress elicited the release of cytochrome c into the cytosol during apoptosis. These findings suggested that the activation of caspases accompanied by a cytochrome c release in response to hypoxia was involved in apoptotic cell death in MC3T3E1 osteoblasts.
Anoxia* ; Apoptosis* ; Blotting, Western ; Caspase 3 ; Caspase 6 ; Caspases ; Cell Death ; Cytochromes c ; Cytosol ; DNA ; DNA Fragmentation ; Lamin Type A ; Osteoblasts* ; Oxygen ; Signal Transduction*

Nickel and chromium are two major metals used in the alloys of most orthodontic appliances. But these metals are known to cause hypersensitivity, dermatitis, and asthma. In addition, a significant carcinogenic and mutagenic potential has been demonstrated for compounds containing these metals. The purpose of this study was to find out how much nickel and chromium was released from orthodontic appliances, and which factors would influence the release. The simulated orthodontic appliances were constructed for a half of a mandibular arch and incubated in 0.05% NaCl solution at 37degrees C. Nickel and chromium release was quantified with an Inductively Coupled Plasma (ICP) spectroanalyzer. The results were as follows : 1. From simulated orthodontic appliances, nickel was released 9.83-70.0microgram/day but the release of chromium was not detectable in limit of 10ppb. 2. The amount of nickel release was significantly different between the types of appliances. 3. The galvanic condition increased the amount of nickel release, which was not statistically significant. 4. The sand blasting increased the amount of nickel release, which was also not statistically significant.
Alloys ; Asthma ; Chromium* ; Dermatitis ; Hypersensitivity ; Metals ; Nickel* ; Orthodontic Appliances* ; Plasma ; Silicon Dioxide

PURPOSE: Adjuvant chemotherapy (aCT) in rectal cancer patients who have undergone curative resection after neoadjuvant chemoradiation (nCRT) is controversial. We aimed to investigate the benefits of using aCT and the clinical impact of completing aCT in ypstage 2 rectal cancer patients.METHODS: We retrospectively reviewed clinicopathological data from patients who had undergone radical resection after nCRT between January 2006 and December 2012. In total, 152 patients with ypT3/4N0M0 rectal cancer were included. Of these patients, 139 initiated aCT, while 13 did not receive aCT (no-aCT). Among those who received aCT, 132 patients completed their planned cycles (aCT-completion) whereas 7 did not (aCT-incompletion). All patients received longcourse chemoradiation; a 5-fluorouracil-based regimen was used for nCRT in most patients. The prognostic factors affecting disease-free survival (DFS) and overall survival (OS) were analyzed.RESULTS: The median follow-up duration was 41 months. Demographic data did not differ significantly among the 3 groups. In multivariate analysis, open surgery, a tumor size >2 cm, retrieval of <12 lymph nodes, circumferential resection margin (CRM) positivity and aCT incompletion were independent prognostic factors for poor DFS. Old age (≥60 years), open surgery, CRM positivity, aCT incompletion, and lack of aCT initiation compared to aCT completion were independent prognostic factors for poor OS.CONCLUSION: In ypstage 2 rectal cancer patients, aCT after nCRT and total mesorectal excision affected both DFS and OS; however, only patients who completed planned aCT exhibited survival benefits. Therefore, improving patients’ compliance with the completion of aCT is desirable.
Chemoradiotherapy ; Chemotherapy, Adjuvant ; Compliance ; Disease-Free Survival ; Follow-Up Studies ; Humans ; Lymph Nodes ; Multivariate Analysis ; Neoadjuvant Therapy ; Rectal Neoplasms ; Retrospective Studies

Cudrania tricuspidata Bureau (CTB), a species of the Moraceae plant, has been used as a bruise recovery treatment. This study aimed to determine whether the 75 kDa phytoglycoprotein extracted from CTB has a regulatory effect on the proliferation of human colon epithelial cells and the pathological process of inflammatory bowel disease (IBD). We found that CTB glycoprotein significantly induces the proliferation of human colon epithelial HT-29 cells by activating protein kinase C. CTB glycoprotein stimulated the phosphorylation of c-Jun N-terminal kinase and transcription factor nuclear factor-κB, which are responsible for the expression of cell-cycle-related proteins (CDK2, CDK4, cyclin D1 and cyclin E) during its promotion of cell proliferation. Experimental colitis was induced in mice by adding dextran sulfate sodium to their drinking water at a concentration of 4% (W/V) for seven days. We found that CTB glycoprotein ameliorates the pathological process of IBD and lowers the disease activity index score, which was composed of body weight change, diarrhea, and hematochezia in ICR mice treated with dextran sulfate sodium. Hence, we suggest that CTB glycoprotein has the ability to prevent IBD by promoting cell proliferation signaling events via the activation of PKC, JNK and NF-κB in colon epithelial cells.