This study aimed to determine the optimum orthodontic force from a broader perspective. Interleukin (IL)-1β levels in human gingival crevicular fluid (GCF), pain intensity, and the amount of tooth movement were measured during canine retraction using different magnitudes of continuous orthodontic force. Sixteen subjects (two males and 14 females), aged 18-24 years, diagnosed with Class I bimaxillary protrusion and treated with first premolar extractions participated in this study. The upper canines were retracted with continuous forces of 50 or 150 g using nickel-titanium coil springs on segmented archwires. One of the lower canines was used as a control. GCF was collected from the distal site of each tooth at specific time points. IL-1β concentrations, pain intensity, using the visual analogue scale (VAS), and the amount of tooth movement were evaluated. One-way analysis of variance, Friedman, and paired t-tests were used for comparisons of IL-1β in GCF, the plaque and gingival indices, and the efficiency of tooth movement on pain perception, respectively. IL-1β concentration in the 150 g group showed the highest level at 24 hours and 2 months with significant differences compared with the control group (P < 0.05). The mean VAS score of pain intensity from the 150 g force was significantly greater than from the 50 g force at 24 hours (P < 0.01). However, no significant difference in the amount of tooth movement was found between these two different magnitudes of continuous force at 2 months. A 50 g force could effectively induce tooth movement similar to 150 g with less pain and less inflammation.

ABSTRACT-Alkaline phosphatase (ALP) is supposed to be important for bone formation; however, its role is not clear. In this study, we examined the importance of enzymatic activity of ALP and anchoring of ALP protein to the cells for mineralization of an osteoblastic cell line, MC3T3-E1. While we cultured the cells in the presence of tetramisole, an inhibitor of ALP activity, ALP protein was expressed at a similar level to that in the control. Although tetramisole showed no effect on cell growth and increased hydroxyproline accumulation, it decreased the osteocalcin production and the accumulation of calcium and phosphate in the matrices. Tetramisole also inhibited mineralized nodule formation, which was observed by optical microscopy and detected by Von Kossa staining. On the other hand, when ALP protein was released from the cell membranes with the use of phosphatidylinositol-specific phospholipase C, no marked changes were detected in hydroxyproline, calcium and phosphate accumulations in the matrices at late calcification stage, which was consistent with the morphological findings. These results clearly show that enzymatic activity of ALP is necessary for mineralization of MC3T3-E1 cells, but not the presence of ALP protein or anchoring of ALP to the cells.Keywords: Alkaline phosphatase, Mineralization, Phosphatidylinositol-specific phospholipase C, Osteoblastic cell, TetramisoleBone-type alkaline phosphatase (ALP) is supposed to play a key role in the formation and calcification of hard tissues from accumulated circumstantial evidence (1). Although a number of theories have been proposed, its precise function is not well understood yet (2 -6). It is not even clear whether ALP is really indispensable to mineralization.ALP is attached to the external surfaces of plasma membranes by phosphoethanolamine bound to oligosaccharide, which is, in turn, covalently linked to the polar head group of phosphatidylinositol (7 -9). ALP is released from plasma membranes by phosphatidylinositol-specific phospholipase C (PIPLC) (10 -13).We previously reported that ALPs of MC3T3-E1 cells were released into the medium during cell culture and the time course of the increase of ALP in the medium was consistent with the progress of mineralization (14). We assumed that matured and released ALP might be closely related to the mineralization. An alternative report demonstrated that ALP attached covalently to the external surface of plasma membranes was involved in the mineralization of hard tissues (15).Our aim in this study was to clarify the importance of enzymatic activity of ALP and anchoring of ALP to the cells for mineralization. We used an osteoblastic cell line, MC3T3-E1 cells, which were established from fetal murine calvalial cells (16). The cells differentiate into osteoblasts and then produce ALP and process procollagens to collagens; finally the cells form mineralized tissues in vitro. We studied the effects of tetramisole, an inhibitor of ALP activity, and PIPLC additions to culture medium on mineralization of MC3T3-E1 c...

Tumor blood vessels play an important role in tumor progression and metastasis. It has been reported that tumor endothelial cells (TECs) exhibit highly angiogenic phenotypes compared with those of normal endothelial cells (NECs). TECs show higher proliferative and migratory abilities than those NECs, together with upregulation of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2). Furthermore, compared with NECs, stem cell markers such as Sca-1, CD90, and multidrug resistance 1 are upregulated in TECs, suggesting that stem-like cells exist in tumor blood vessels. In this study, to reveal the biological role of stem-like TECs, we analyzed expression of the stem cell marker aldehyde dehydrogenase (ALDH) in TECs and characterized ALDHhigh TECs. TECs and NECs were isolated from melanoma-xenografted nude mice and normal dermis, respectively. ALDH mRNA expression and activity were higher in TECs than those in NECs. Next, ALDHhigh/low TECs were isolated by fluorescence-activated cell sorting to compare their characteristics. Compared with ALDHlow TECs, ALDHhigh TECs formed more tubes on Matrigel-coated plates and sustained the tubular networks longer. Furthermore, VEGFR2 expression was higher in ALDHhigh TECs than that in ALDHlow TECs. In addition, ALDH was expressed in the tumor blood vessels of in vivo mouse models of melanoma and oral carcinoma, but not in normal blood vessels. These findings indicate that ALDHhigh TECs exhibit an angiogenic phenotype. Stem-like TECs may have an essential role in tumor angiogenesis.

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(243/250 words)Murine nasopharynx-associated lymphoid tissue (NALT), located at the base of the nasal cavity,

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Objective : To assess the congenital and postnatal factors that affect degree of malocclusion in patients with unilateral cleft lip and palate using multivariate statistical analysis. Design : Retrospective study. Patients : All information on 135 subjects with unilateral cleft lip and palate was obtained from an oral examination and radiograph at the initial examination at an orthodontic clinic and from surgical records. Plaster models were taken before orthodontic treatment. The ages of the subjects ranged from 5 to 8 years with a mean age of 6.9 years. All primary surgeries for the patients were performed at a university hospital. Main Outcome Measures : The GOSLON Yardstick was used to assess the dental arch relationships (degree of malocclusion) in patients. Family history of Class III, degree of cleft, and congenitally missing upper lateral incisor on the cleft side were chosen as congenital factors inducing malocclusion. Presurgical orthopedic treatment, cheiloplasty, and palatoplasty were chosen as postnatal factors. Associations between various factors and dental arch relationships were assessed using logistic regression analysis. Results : According to adjusted odds ratios, family history of Class III is associated with a significantly worse dental arch relationship. Palatoplasty using push-back alone correlated to a dental arch relationship that was significantly worse than palatoplasty using push-back with a buccal flap. Conclusions : Multivariate analysis shows evidence that a positive family history of Class III and palatoplasty using push-back alone are associated with worse malocclusion of unilateral cleft lip and palate patients.