Contact Co-culture of Osteoblasts and Sympathetic Neuronal Cells Promotes Differentiation of Both Cell Types.

BACKGROUND/AIM: Bone and nerve reconstruction is crucial for treating various diseases of the oral and maxillofacial region. However, the relationship between bone and nervous system has not yet been fully elucidated. Therefore, we aimed to examine the interaction between osteoblasts and neuronal cells in contact co-culture. MATERIAL AND METHODS: Osteoblasts and sympathetic neuronal cells were grown in contact co-culture. Microscopic observation, a mineralization assay, immunofluorescence staining, and DNA microarray analysis were performed. RESULTS: Microscopic observation revealed morphological changes in the osteoblasts that were cocultured with sympathetic neuronal cells. Contact co-culture enhanced osteoblast calcification and upregulated a neuronal marker. Not only osteoblast differentiation signals, but also neuronal signals were increased in murine osteoblasts that were co-cultured with rat sympathetic neuronal cells. We also found that not only rat neuron differentiation signals, but also osteoblast differentiation signals were increased in rat sympathetic neuronal cells that were co-cultured with murine osteoblasts. CONCLUSION: In the contact co-culture with osteoblasts and sympathetic neuronal cells, the sympathetic neuronal cells promoted osteoblast differentiation, and the osteoblasts promoted neuron differentiation.

MicroRNA-204 regulates osteogenic induction in dental follicle cells.

The dental follicle is an ectomesenchymal tissue surrounding developing tooth germ that contains osteoblastic-lineage-committed stem/progenitor cells. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression during stem cell growth, proliferation, and differentiation. The aim of this study was to investigate the key regulators of miRNA during osteogenic differentiation in human dental follicle cells (hDFC). We analyzed miRNA expression profiles in hDFC during osteoblastic differentiation. Expression of miR-204 was decreased in hDFC during osteogenic induction on microarray analysis. Real-time and RT-PCR analysis also showed that the expression of miR-204 was decreased in all three hDFC during osteogenic differentiation. To investigate whether miR-204 has an effect on osteogenic differentiation, miR-204 was predicted to target alkaline phosphatase (ALP), secreted protein acidic and rich in cysteine (SPARC), and Runx2 in the in the 3'-UTRs by in silico analysis. When miR-204 was transfected into hDFC, the activity of ALP and protein levels of SPARC and Runx2 were decreased. mRNA levels of ALP, SPARC and Runx2 were also decreased by miR-204 transfection. Our data suggest that miR-204 negatively regulates the osteogenic differentiation of hDFC by targeting the bone-specific transcription factor Runx2, the mineralization maker ALP and the bone extracellular matrix protein SPARC.

Repeated Live Imaging in the Temporomandibular Joint of an Anterior Crossbite Mouse Model Using a 7T Magnetic Resonance Device.

BACKGROUND/AIM: Few studies have performed magnetic resonance (MR) imaging on live animals. The aim of this study was to perform 7T MR microimaging of the temporomandibular joint (TMJ) multiple times in the same living mice with malocclusion, and to compare between MR imaging and histopathological findings. MATERIALS AND METHODS: Mice were examined by MR imaging at 3-4, 6 and 12 weeks following the attachment of a metal tube on the left mandibular incisor. Histopathological examination was done at 3, 6 and 12 weeks. RESULTS: The detailed structure of the TMJ was evident from MR microimaging. The histopathological examination showed some changes in the cartilage, but no changes in the bone structure of these mice. CONCLUSION: We successfully performed multiple 7T MR imaging in living mice. Even if the TMJ showed no obvious changes on MR images, minute changes may be present in the cartilage.

Relationship Between Intracapsular Fracture Patterns and Arthroscopic Findings.

PURPOSE: To observe the superior joint compartment (SJC) using ultrathin arthroscopy in intracapsular condylar fracture (ICF) of the temporomandibular joint, describe the changes, and evaluate the relations among fracture pattern, arthroscopic findings, and clinical outcome. PATIENTS AND METHODS: Twenty patients with 27 ICFs were the subject group. Thirteen patients had unilateral ICFs and 7 had bilateral ICF. The fracture patterns were classified into 9 categories, and all patients had arthroscopic examination of the traumatized joint at the time of definitive treatment. At 4 months after treatment of the injury, all patients had a secondary arthroscopy of the ICF joint. In all patients, range of motion (ROM) was measured as the interincisal distance (millimeters) at the first visit to 12 months after the first treatment, and the data were statistically evaluated. RESULTS: Intra-articular hyperemia, hypervascularity, and temporal bone damage were found, and 4 patients had disc perforations at the first examination. At the second arthroscopy 4 months later, normal healing occurred in 11 joints, all of which had minimally displaced fractures. Fifteen joints showed complete filling of the SJC, all of which had a displaced minor fragment from the fossa. Comparison of the effect of the presence versus absence of SJC fibrosis on ROM showed marked differences from 1 to 12 months. The effect of early versus delayed definitive treatment showed marked differences at 4 and 12 months. CONCLUSION: The intra-articular condition at 4 months after ICF as observed arthroscopically was related to the minor fragment position. If the minor fragment is nondisplaced, then it will heal to a normal state; however, if the minor fragment is displaced from the fossa, then the SJC shows disc damage and fibrosis. This could lead to fibrous ankylosis.

Changes to Muscle T2after Single-finger Exercise Measured with 0.2T MR Imaging.

We constructed an arm holder for muscle exercise from a forearm-shaped plastic shell and magnetic resonance (MR) imaging position markers and determined the echo time (39 ms) for T2-weighted spin-echo MR imaging from T2values of the exercised (50 ms) and resting (32 ms) muscle at 0.2 tesla. The smallest detectable muscle was the extensor digiti minimi muscle (cross-sectional area 25 mm²). This combination could be useful to monitor finger exercise in patients undergoing physical therapy.

Structure and Size-selective Permeability of the Synovial Membrane of the Temporomandibular Joint of the Mouse Measured by MR Imaging at 7T.

PURPOSE: We analyzed the anatomical structure of the temporomandibular joint (TMJ) and molecular weight dependency of synovial membrane permeability in mice using 7-tesla magnetic resonance (MR) imaging. METHODS: We obtained 3-dimensional (3D) T1-weighted gradient echo (3D-T1W) and 3D T2-weighted rapid acquisition with relaxation enhancement (3D-T2W RARE) MR images of the TMJ of male C57BL6 mice with voxel resolution of 65 µm. Two-dimensional (2D) T1w images were measured every 45 s before and after bolus intravenous (IV) injection of contrast reagents: gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA; 0.5 kDa); oligomer-based contrast agent (CH3-DTPA-Gd; 2.1 kDa); gadolinium-labeled polylysine (Gd-polylysine; 10 kDa); and gadolinium-labeled albumin (Gd-albumin; 74 kDa). RESULTS: T1W images depicted the temporal bone and mandibular condyle as regions with lower signal intensity and the disc as a region of intermediate intensity. In the Gd-DTPA-enhanced T1W and T2W images, the articular disc could be identified as a region with lower signal intensity than that of the upper and lower joint cavities. After IV injection of Gd-DTPA or CH3-DTPA-Gd, the signal intensity of the joint cavities increased within 10 min, but this increase was not shown with Gd-polylysine and Gd-albumin. CONCLUSION: The structural findings obtained by MR imaging agreed with those obtained by hematoxylin-eosin staining under light microscopy. Contrast-enhanced MR imaging suggested that smaller (<2.1 kDa) but not larger (>10 kDa) molecules can permeate the synovial membrane. Our results suggest the utility of MR imaging for analyzing the structure of the TMJ as well as permeability of the synovial membrane.

Prevalence of extended-spectrum ß-lactamase-producing Escherichia coli and Klebsiella pneumoniae in food-producing animals.

To evaluate the diversity of extended-spectrum ß-lactamases (ESBL) genes among food-producing animals, 48 isolates of ESBL-producing Escherichia coli isolates were obtained from rectal samples of broilers, layers, beef cattle and pigs, at the slaughterhouse level. ESBL-carrying E. coli were isolated from 60.0% of individual broiler rectal samples, 5.9% of layers, 12.5% of beef cattle and 3% of pigs. One ESBL-producing Klebsiella pneumoniae was isolated from a broiler. The ESBL-positive E. coli isolates from broilers harbored various ESBL genes: bla (SHV-12), bla(CTX-M-2), bla(CTX-M-14), bla(CTX-M-15) and bla(CTX-M-44). The plasmid DNAs were analyzed by restriction patterns. Homogeneous band patterns were yielded in those of K. pneumoniae and E. coli isolates harboring the bla(CTX-M-2) gene from different farms. No genetic relation between the 2 CTX-M-14 ESBL-producing strains was found by pulsed-field gel electrophoresis, although 2 plasmids in these strains, obtained from different broiler farms, were similar to each other. This study provides evidence that the proliferation of CTX-M-producing E. coli is due to the growth of indigenous CTX-M-producing strains and the possible emergence of strains that acquired CTX-M genes by horizontal transfer in different broiler farms. CTX-M-producing coliforms in broilers should be controlled due to the critical importance of cephalosporins and the zoonotic potential of ESBL-producing bacteria.

Terfenadine antagonism against interleukin-4-modulated gene expression of T cell cytokines.

Here, we investigated whether an anti-allergy drug, terfenadine, affects interleukin-4-modulated cytokine expression in peripheral T cells. Peripheral blood T cells were first stimulated with recombinant interleukin-4 and then tested for modulation of the mRNA of a panel of cytokines using the reverse transcription-polymerase chain reaction followed by Southern blot analysis. It was found that T cells constitutively expressed mRNA specific to T helper 1 cytokines (interleukin-2, interferon-gamma, tumor necrosis factor-alpha), which was markedly downregulated upon stimulation with interleukin-4, whereas mRNA for T helper 2 cytokines such as interleukins 4, 5, and 6 was induced in response to interleukin-4. Interestingly, the interleukin-4-induced expression of all T helper 2 cytokines examined was markedly downregulated by terfenadine. Among T helper 1 cytokines, interleukin-4-mediated suppression of tumor necrosis factor-alpha was not affected by terfenadine, which, however, markedly restored mRNA expression of interferon-gamma or interleukin-2. Electrophoretic mobility shift assays using [32P]-labeled synthetic oligonucleotides encoding the consensus binding motif of activator protein-1 demonstrated that interleukin-4-induced binding of activator protein-1 composed of JunB was interfered by terfenadine. This study indicates that terfenadine, at least partially, interferes with interleukin-4-activated signaling, leading to terfenadine antagonism against the modulatory impact of interleukin-4 on T cell cytokines.

A cyclic tetramer of [Ag(1,4,7-trithiacyclononane)]+, cyclo-tetrakis(mu-1,4,7-trithiacyclononane-kappa3S1,S4,S7:kappaS1)tetrasilver(I) tetrakis(trifluoromethanesulfonate) nitromethane disolvate.

(1,4,7-Trithiacyclononane)silver trifluoromethanesulfonate crystallizes in a tetrameric form from nitromethane, to give the title compound, [Ag(4)(C(6)H(12)S(3))(4)](CF(3)SO(3))(4) x 2CH(3)NO(2). The complex cation consists of four [AgL]+ units (L is 1,4,7-trithiacyclononane), with four Ag-S-Ag bridges forming a cyclic tetramer. The almost planar Ag(4)S(4) ring takes an octagonal form.

Overactivation of IL-4-induced activator protein-1 in atopic dermatitis.

Atopic dermatitis is regarded as mediated by Th2-type immunity. In fact, it frequently coincides with the elevation of immunoglobulin (Ig)-E in patients' sera. Due to the pivotal role of interleukin (IL)-4 in regulation of IgE, we hypothesized if atopic dermatitis represents a hyper-reactive condition in response to IL-4 when it coincides the higher serum level of IgE. To address this possibility, peripheral blood mononuclear cells (PBMC) isolated from patients with atopic dermatitis with the high serum IgE level, from those with psoriasis or from healthy volunteers were stimulated with recombinant IL-4 and analyzed for activation of transcription factors including activator protein (AP)-1 or signal transducers and activators of transcription (STAT)-6 by employing electrophoretic mobility shift assays. Although no significant difference between atopy patients and other groups was observed in the STAT-6 binding activity in IL-4-stimulated PBMC, it over-activated the binding of AP-1 in PBMC of the patients with atopic dermatitis. The AP-1 binding was interfered by the use of an antibody directed against JunB. This is the indication that IL-4-overactivated AP-1 is composed of JunB. Furthermore, semi-quantitative RT-PCR analyses revealed marked down-modulation of a Th1 cytokine, interferon (IFN)-gamma, in IL-4-stimulated PBMC derived from atopy patients, but not that from healthy individuals. Together, our present study indicates that AP-1 is over-activated by IL-4 in PBMC of the atopic patients with the higher IgE level, thereby implying that IL-4-induced over-activation of AP-1 might be one of pathogenic factors in atopic dermatitis.