Effects of retraction force and anchorage reinforcement on occlusal force: a model study.

OBJECTIVES: The aim of this study was to investigate the effects of retraction force and anchorage reinforcement with orthodontic mini implants on occlusal force. MATERIALS AND METHODS: A strain gauge was attached to the palatal surface of the maxillary right first molar on an en masse retraction model. RESULTS: Occlusal forces were measured from this model, according to different retraction forces that were generated by elastic chain, under varied compressive forces (simulating masticatory forces). This retraction experiment was then performed again, after using anchorage reinforcement with an orthodontic mini implant. Occlusal force decreased as retraction force increased. The decrease showed a significant difference above 150g of retraction force (P < 0.05) and was more definite under compressive force higher than 150 N (P < 0.001). After anchorage reinforcement with the orthodontic mini implant, however, occlusal force did not significantly decrease with increasing retraction force. Significant differences in occlusal force were noted between the conditions with and without anchorage reinforcement when the applied retraction force was greater than 200g. CONCLUSION: Occlusal force tends to decrease during retraction, and this decrease can be prevented by anchorage reinforcement with orthodontic mini implants. LIMITATIONS: Further investigation on the actual masticatory process in humans is required for more clear clinical implication.

Ionic Association in CH3-(CH2-CF2) n -CH3(PVDF)-Li+-(CF3SO2)2N- for n = 1, 4: A Computational Approach.

The ionic conductivity of solid polymer electrolytes is governed by the ionic association caused by the polymer···Li+ and the anion···Li+ interactions. We performed the density functional calculation to analyze the molecular interactions in the CH3-(CH2-CF2) n -CH3-Li+-(CF3SO2)2N- for n = 1,4 systems. The gauche conformation is predicted in the lowest energy conformer of pure polymer except for n = 1. The lithium coordination number with the polymer is changed from 3 to 2 in the presence of anion for n = 2, 4 systems. The consequences of the Li+ ion and Li+-(CF3SO2)2N- to the vibrational spectrum are studied to understand the ionic association at the molecular level.

Effect of Bulky Anion around the Dication on the Electronic Structure and Normal Frequencies in 1,3-Bis(3-methylimidazolium-1-yl)propane Bis(trifluoromethanesulfonyl)imide Ionic Liquid.

A manifestation of hydrogen bonding between the dication and anions attributed to their relative position of the anions around the cation can influence both the conformational equilibrium and the physical properties of ionic liquids. With this view, we studied the electronic structure and normal frequencies using density functional theory calculations to analyze the hydrogen-bonding interactions in dicationic ionic liquids. The conformers are distinguished based on the hydrogen-bonding sites of the cation and anion. The weak hydrogen bonding between the dication and anions in dication ionic liquids can lead to greater conformational equilibrium compared to the monocation system. Consequences of these interactions for the vibrational spectrum are analyzed to provide an insight into the conformational equilibrium in dicationic ionic liquids at the molecular level.

[A case of rhabdomyolysis during hospitalization for acute hepatitis A].

A 29-year-old man was admitted to hospital with fever, myalgia, and sore throat. Initial laboratory findings were compatible with acute hepatitis; he was positive for the serologic marker for acute hepatitis A. On the 3rd day of admission, in spite of normalization of body temperature and a reduction in serum liver enzyme levels, serum levels of creatinine phosphokinase had increased up to 16,949 U/L. The patient recovered with supportive therapy and was discharged on the 12th day. We report a case of acute hepatitis A complicated by rhabdomyolysis during hospitalization.

[A case of choledochoduodenal fistula as a delayed complication after biliary metallic stent placement in distal cholangiocarcinoma].

Biliary drainage in patients with malignant biliary obstruction relieves jaundice and prevents the development of cholangitis or hepatic failure from biliary obstruction. Therefore, this may result in better quality of life along with survival prolongation. Biliary stent placement is an effective and safe measure for biliary decompression and is preferred than bypass surgery in high risk patients. Entero-biliary perforation-communication is one of the rare complications of biliary stent. We herein report a case of duodeno-biliary perforation-communication in patient with distal cholangiocarcinoma who presented with duodenal ulcer and obstruction, occurring 4 years later from the metallic biliary stent insertion. Patient was managed with a pyloric metal stent and conservative care.

Olig2 is expressed late in human eosinophil development and controls Siglec-8 expression.

Oligodendrocyte transcription factor 2, a basic helix-loop-helix transcription factor that binds to E-box motifs, is known to have a key role in determining lineage specification of oligodendrocytes and motor neurons. In the present study, we report that oligodendrocyte transcription factor 2 is expressed in human eosinophils and involved in transcriptional activation of the gene encoding sialic acid binding immunoglobulin-like lectin 8 (Siglec-8), a late eosinophil-differentiation marker known to exert eosinophil apoptosis. When cord blood CD34+ hematopoietic stem cells differentiated toward eosinophils during a 24-d culture period, oligodendrocyte transcription factor 2 protein was expressed in cord blood eosinophils on d 24, a time when cord blood eosinophils are considered fully differentiated, whereas it was not detectable on d 18 or at earlier time points. Oligodendrocyte transcription factor 2 protein was also abundantly expressed in human peripheral-blood eosinophils but not in neutrophils, monocytes, lymphocytes, or cord blood mast cells. RNA sequencing analysis showed that numerous genes, especially those encoding eosinophil surface molecules, were highly up-regulated along with OLIG2 Among the genes examined, SIGLEC-8 messenger RNA and protein were markedly down-regulated in parallel with OLIG2 by an oligodendrocyte transcription factor 2 small interfering RNA or a short hairpin RNA, as evidenced by real-time polymerase chain reaction, fluorescence-activated cell sorting, and Western blot analyses. In reporter gene and chromatin immunoprecipitation experiments, an E-box in the first intron was found to stimulate SIGLEC-8 gene transcription and to bind oligodendrocyte transcription factor 2. Hence, at least one important aspect of eosinophil differentiation is regulated by oligodendrocyte transcription factor 2, a transcription factor that has not previously been reported, to our knowledge, in normal granulocytes.

Compact microwave ion source for industrial applications.

A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

CpG methylation at GATA elements in the regulatory region of CCR3 positively correlates with CCR3 transcription.

DNA methylation may regulate gene expression by restricting the access of transcription factors. We have previously demonstrated that GATA-1 regulates the transcription of the CCR3 gene by dynamically interacting with both positively and negatively acting GATA elements of high affinity binding in the proximal promoter region including exon 1. Exon 1 has three CpG sites, two of which are positioned at the negatively acting GATA elements. We hypothesized that the methylation of these two CpGs sites might preclude GATA-1 binding to the negatively acting GATA elements and, as a result, increase the availability of GATA-1 to the positively acting GATA element, thereby contributing to an increase in GATA-1-mediated transcription of the gene. To this end, we determined the methylation of the three CpG sites by bisulfate pyrosequencing in peripheral blood eosinophils, cord blood (CB)-derived eosinophils, PBMCs, and cell lines that vary in CCR3 mRNA expression. Our results demonstrated that methylation of CpG sites at the negatively acting GATA elements severely reduced GATA-1 binding and augmented transcription activity in vitro. In agreement, methylation of these CpG sites positively correlated with CCR3 mRNA expression in the primary cells and cell lines examined. Interestingly, methylation patterns of these three CpG sites in CB-derived eosinophils mostly resembled those in peripheral blood eosinophils. These results suggest that methylation of CpG sites at the GATA elements in the regulatory regions fine-tunes CCR3 transcription.