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To cite this article: Marquez Hernandez RA, Ohtani J, Fujita T, Sunagawa H, Ishikawa E, Tsubamoto N, Kawata T, Kaku M, Motokawa M, Tanne K: Mandibular and femoral growth alteration after sex hormone disruption in growing mice Orthod Craniofac Res 2011;14:63–69 Structured Abstract Authors – Marquez Hernandez RA, Ohtani J, Fujita T, Sunagawa H, Ishikawa E, Tsubamoto N, Kawata T, Kaku M, Motokawa M, Tanne K Objectives – To investigate how mandibular and femoral growth is affected when sex hormone– specific receptor antagonist is administered in growing mice. Materials and methods – Forty C57BL/6J mice were used in this experiment. At 5 days of age, the mice received daily injection of estrogen receptor alpha (ERα), beta (ERβ), or androgen receptor (AR) antagonists, and their body weight was assessed every 4 days. One, four and eight weeks after the initial injection, radiographs of the mandible and femur were taken and measured. Analyses of variance and pairwise comparisons (Fisher) were performed to examine the differences in values measured among the groups. Results – Mandibular growth was affected by ERβ antagonist injection in male mice at 4 and 8 weeks. In female mice, the growth was affected during all the experimental period, when ERβ was administered. Moreover, at 8 weeks, mandibular growth was also affected in male and female mice injected with ERα antagonist and in male mice injected with AR antagonist. Femoral growth was affected during all the experimental period in male and female mice injected with ERβ antagonist. Moreover, at 8 weeks, the growth was affected in male and female mice injected with ERα antagonist and in male mice injected with AR antagonist. Conclusions – Growth of the mandible and femur in mice, in part, is induced in response to the stimulation of ERβ in chondrocytes before and during early puberty. In late and after puberty, the growth is induced by the stimulation of ERα in male and female mice and that of AR in male mice.

This report describes the treatment of a case of severe open bite with posterior crossbite. While treating open bite, the outcome may not always be successful with orthodontic therapy alone. In such cases, surgical therapy is often chosen to gain a stable occlusion. Skeletal anchorage systems such as miniscrews are now frequently used for correcting severe malocclusion. In this report, we treated an open bite by intruding the molars with miniscrews placed bilaterally in the interdental space between both the upper and lower posterior teeth. The active treatment period was 36 months and the patient's teeth continued to be stable after a retention period of 36 months.

summary The aim of this study was to estimate numerically the properties of masseter motor units (MUs) in relation to bite force magnitude and direction three-dimensionally and to confirm the hypothesis that the properties differ between different parts of the muscle by means of simultaneous recording of MU activity along with the MU location and three-dimensional (3D) bite force. The MU activity of the right masseter of four healthy men was recorded using a monopolar needle electrode in combination with a surface reference electrode. The location of the needle electrode was estimated stereotactically with the aid of magnetic resonance images and a reference plate. The magnitude and direction of the bite force was recorded with a custom-made 3D bite force transducer. The recorded bite force was displayed on a signal processor, which enabled the participant to adjust the direction and magnitude of the force. The activities of 65 masseter MUs were recorded. Each MU had specific ranges of bite force magnitude and direction (firing range: FR) and an optimum direction for recruitment (minimum firing threshold: MFT). There was a significant negative correlation between MFT and FR width. There were functional differences in MU properties between the superficial and deep masseter and between the superficial layer and deep layer in the superficial masseter. These results indicate that the contribution of human masseter motor units to bite force production is heterogeneous within the muscle.

It is suggested that osteopontin may promote osteoclast binding to resorptive sites by interacting with the alphavbeta3 receptor on osteoclasts. However, the role of osteopontin in functional remodeling of bony structures remains unclear. The present study was conducted to examine the distribution of osteopontin on the condyle and explore the role in condylar remodeling in growing rats using an immunohistochemical method. Twenty Wistar strain male rats aged 7, 14, 28 and 56 days were used. In 7- and 14-day-old rats, no immunoreaction to osteopontin was detected in the cartilage cells. In 28-day-old rats initiating mastication, the thickness of condylar cartilage was decreased abruptly as compared to the younger rats. High immunoreaction to osteopontin was found in the cytoplasm of hypertrophic chondrocytes and on the trabecular bone surfaces of primary spongiosa adjacent to the osteoclasts or chondroclasts. The immunoreactions to osteopontin in the cytoplasm of hypertrophic chondrocytes were less in 56-day-old rats than in 28-day-old rats. It is shown that the alteration in mechanical loading on the mandibular condyle due to functional changes from weaning to mastication correlates with the localization of osteopontin in growing rats. Furthermore, it is suggested that osteopontin may stimulate osteoclastic resorption of calcified matrix by mediating the attachment of osteoclasts and/or chondroclasts during growth-related functional remodeling of the condyle.

1,8-Di(2-thienyl)-, 1,8-bis(5,2′-bithiophene-2-yl)-, 1,8-bis(5,2′:5′,2″-terthiophene-2-yl)-, and 1,8-bis-(5,2′:5′,2″:5″,2″′-quaterthiophene-2-yl)naphthalenes (1a, 1b, 1c and 1d, respectively) were synthesized starting from 1,8-dibromonaphthalene by appliction of NiCl2(dppp)-catalyzed coupling of aryl bromides with thienylmagnesium bromides. For comparison with these compounds, 1-(2-thienyl)-, 1-(5,2′-bithiophene-2-yl)-, 1-(5,2′:5′,2″-terthiophene-2-yl)-, and 1-(5,2′:5′,2″:5″,2″′-quaterthiophene-2-yl)naphthalenes (2a–d) were also prepared. Inspection of 1H and 13C NMR and UV/Vis data of 1a–d and 2a–d including X-ray single crystal structure data of 1b suggests that the planes of two oligothiophene units of 1a–d are approximately parallel to each other and are at large angles to the naphthalene ring. In accordance with these findings, CV oxidation potential data show that the radical cations formed from 1a–d are stabilized by intramolecular electron transfer interaction of the two oligothiophene units.

1. Chronic volume expansion by dietary salt loading practically abolishes tubuloglomerular feed-back (TGF) by means of a humoral inhibitor in tubular fluid. Elimination of the vasoconstrictor influence of feed-back does not, however, increase glomerular filtration rate (GFR) and renal blood flow (RBF), implying that chronic salt loading induces additional preglomerular vasoconstriction. This being so, the feed-back response which, although absent in free-flowing nephrons, can still be elicited by loop of Henle perfusion with Ringer solution, should be essentially normal, except that nephron GFR at any loop perfusion rate should be lower than in controls. Persistence of RBF, GFR and nephron GFR autoregulation would imply that autoregulation is achieved by a preglomerular resistance control system independent of feed-back. 2. These hypotheses were tested by clearance and micropuncture experiments in rats chronically fed a diet containing 40 g NaCl (kg food)-1. 3. RBF and GFR autoregulation indeed persisted, the former down to 90 mmHg compared with 105 mmHg in controls. In controls, nephron GFR measured distally was autoregulated down to 90 mmHg whereas that measured proximally was autoregulated only above 105 mmHg. In high-salt rats nephron GFR from both sites was autoregulated to 90 mmHg. 4. Loop of Henle perfusion with homologous tubular fluid in high-salt rats confirmed attenuation of feed-back. Loop perfusion with Ringer solution yielded a response comparable to that in controls (maximal reduction of nephron GFR to 57%, compared with 56% in controls). Absolute nephron GFR at any loop perfusion rate was lower in high-salt rats than in controls. 5. These observations confirm the initial hypotheses. Considering feed-back and autoregulation as independent, preglomerular resistance control mechanisms, together with elementary haemodynamic considerations, allows formulation of a renal haemodynamics model whose quantitative predictions regarding characteristics of RBF, GFR and feed-back control are remarkably consistent with the literature.

The colony-forming ability of haematopoietic cells of W anaemic mice was examined on the macrophage layer formed in the peritoneal cavity of mice. Bone marrow cells of W anaemic mice formed a considerable number of colonies on the macrophage layer, notwithstanding they did not form any colonies in the spleen of the same recipients. As the colony-forming ability of the bone marrow cells was not reduced by the incubation with 3-H-thymidine, most of the cells which formed colonies on the macrophage layer seemed to stay in G0 state. The interrelationship between the spleen colony-forming cells, the macrophage-layer colony-forming cells, and in vitro colony-forming cells was discussed.

Migration of alkyl group from O to S in the reaction of O, S-dialkyl dithiocarbonates with boron trifluoride etherate was studied to elucidate the reaction mechanism on the basis of results from kinetics, crossover reaction, and products formed. It was worthy of note that dialkyl methyl sulfonium fluoroborates were formed in a fairly good yield in reactions with O-alkyl S-methyl dithiocarbonates (alkyl=benzyl and cholesteryl) with boron trifiuoride etherate. Formation mechanism of these by-products was investigated and discussed.