Accuracy of linear measurement using cone-beam computed tomography at different reconstruction angles

Purpose: This study was performed to evaluate the effect of changing the orientation of a reconstructed image on the accuracy of linear measurements using cone-beam computed tomography (CBCT). Materials and Methods: Forty-two titanium pins were inserted in seven dry sheep mandibles. The length of these pins was measured using a digital caliper with readability of 0.01 mm. Mandibles were radiographed using a CBCT device. When the CBCT images were reconstructed, the orientation of slices was adjusted to parallel (i.e., 0°), +10°, +12°, -12°, and -10° with respect to the occlusal plane. The length of the pins was measured by three radiologists, and the accuracy of these measurements was reported using descriptive statistics and one-way analysis of variance (ANOVA); p<0.05 was considered statistically significant. Results: The differences in radiographic measurements ranged from -0.64 to +0.06 at the orientation of -12°, -0.66 to -0.11 at -10°, -0.51 to +0.19 at 0°, -0.64 to +0.08 at +10°, and -0.64 to +0.1 at +12°. The mean absolute values of the errors were greater at negative orientations than at the parallel position or at positive orientations. The observers underestimated most of the variables by 0.5-0.1 mm (83.6%). In the second set of observations, the reproducibility at all orientations was greater than 0.9. Conclusion: Changing the slice orientation in the range of -12°to +12°reduced the accuracy of linear measurements obtained using CBCT. However, the error value was smaller than 0.5 mm and was, therefore, clinically acceptable. © 2014 by Korean Academy of Oral and Maxillofacial Radiology

Antibiotic susceptibility patterns of Helicobacter pylori and triple therapy in a high-prevalence area

This study aims to determine primary Helicobacter pylori resistance and its effect on eradication of the organism. Ninety-two Patients with dyspeptic symptoms were enrolled. H. pylori was cultured and antibiotic sensitivity was determined by the Epsilometer test (Etest) for clarithromycin (CLR), amoxicillin (AMX) and metronidazole (MTR). 23S ribosomal RNA (rRNA) point mutations associated with clarithromycin resistance were also detected. Patients were treated with omeprazole (40 mg daily), CLR (500 mg) and AMX (1g twice a day) for 14 days. A (14)C-urea breath test ((14)C-UBT) was repeated four weeks after completion of treatment to confirm eradication. Triple therapy failure was seen in 30(33%) Patients. The resistance rates were: CLR 33% (30/92), MTR 48% (44192) and AMX (2/92). Clarithromycin resistance (CLR-R) was present in the 16-39 age group in 21 (47%) (P=0.007) compared to nine (19%)in the 40-79 age group. CLR resistance was seen in 30 H. pylori isolates, 20 (67%) from Patients with non-ulcer dyspepsia (NUD), six (20%) with gastric ulcer (GU) and four (13%) with duodenal ulcer (DU). Triple therapy failure was associated with CLR-R in 28 (93%) (

Pancreatic Head Mass from Metastatic Meningeal Hemangiopericytoma

Purpose. To illustrate the propensity of meningeal hemangiopericytoma to spread extraneurally, as a distinction to the ordinary meningioma

Sanguinarine Induces Apoptosis in Papillary Thyroid Cancer Cells via Generation of Reactive Oxygen Species.

Sanguinarine (SNG), a natural compound with an array of pharmacological activities, has promising therapeutic potential against a number of pathological conditions, including malignancies. In the present study, we have investigated the antiproliferative potential of SNG against two well-characterized papillary thyroid cancer (PTC) cell lines, BCPAP and TPC-1. SNG significantly inhibited cell proliferation of PTC cells in a dose and time-dependent manner. Western blot analysis revealed that SNG markedly attenuated deregulated expression of p-STAT3, without affecting total STAT3, and inhibited growth of PTC via activation of apoptotic and autophagy signaling cascade, as SNG treatment of PTC cells led to the activation of caspase-3 and caspase-8; cleavage of PARP and activation of autophagy markers. Further, SNG-mediated anticancer effects in PTC cells involved the generation of reactive oxygen species (ROS) as N-acetyl cysteine (NAC), an inhibitor of ROS, prevented SNG-mediated antiproliferative, apoptosis and autophagy inducing action. Interestingly, SNG also sensitized PTC cells to chemotherapeutic drug cisplatin, which was inhibited by NAC. Finally, SNG suppressed the growth of PTC thyrospheres and downregulated stemness markers ALDH2 and SOX2. Altogether, the findings of the current study suggest that SNG has anticancer potential against PTC cells as well its derived cancer stem-like cells, most likely via inactivation of STAT3 and its associated signaling molecules

First-principles modeling of the polycyclic aromatic hydrocarbons reduction

Density functional theory modelling of the reduction of realistic nanographene molecules (C42H18, C48H18 and C60H24) by molecular hydrogen evidences for the presence of limits in the hydrogenation process. These limits caused the contentions between three-fold symmetry of polycyclic aromatic hydrocarbon molecules and two-fold symmetry of adsorbed hydrogen pairs. Increase of the binding energy between nanographenes during reduction is also discussed as possible cause of the experimentally observed limited hydrogenation of studied nanographenes.Comment: 18 pages, 7 figures, accepted to J. Phys. Chem.

СИНТЕЗ (E,E)-АЗОАЗОМЕТИНОВ НА ОСНОВЕ 4-АМИНОАЗОБЕНЗОЛА

Liquid crystal display devices are widely used in industries such as measuring instrumentation, consumer and industrial electronics, medical equipment and others. The production of these devices is a promising and growing branch of industry in Belarus. The analysis of the liquid crystal device market suggests that the demand for film polarizers of all types (transmissive, reflective and permeable-reflective) will increase due to the constant growth of liquid crystal device manufacture and their scope expanding. Currently, manufacturers of liquid crystal devices in Belarus buy polarizers abroad, and the price is determined by the manufacturers. Obviously, the researches aimed at creating domestic film polarizers of various functional purposes and for the development of technologies for their manufacture, are relevant. 4-aminoazobenzene (aniline yellow colorant) is used in the production of more complex intermediates, dyestuffs, chemical additives to polymers, pharmaceuticals, pesticides, etc. 4-aminoazobenzene is an accessible parent compound for the synthesis of promising compounds for the development of optical materials. By reaction of 4-aminoazobenzene series with vanillin aldehydes in a medium of boiling absolute methanol in the presence of catalytic amounts of glacial acetic acid, (E,E)-azoazomethynes with 75–88 % yields were synthesized. Жидкокристаллические устройства отображения информации широко используются в таких отраслях техники как измерительное приборостроение, бытовая и промышленная электроника, медицинская техника и др. Производство этих устройств является перспективной и развивающейся отраслью промышленности Беларуси. Анализ рынка жидкокристаллических устройств позволяет утверждать, что спрос на пленочные поляризаторы всех типов (пропускающего, отражающего и пропускающе-отражающего) будет возрастать в связи с постоянным ростом выпуска жидкокристаллических индикаторов и расширением сфер их применения. В настоящее время производители жидкокристаллических индикаторов в Республике Беларусь закупают поляризаторы за рубежом, причем цена на них определяется фирмами-изготовителями. Очевидно, что исследования, направленные на создание отечественных пленочных поляризаторов различного функционального назначения и на разработку технологий их изготовления, являются актуальными. 4-Аминоазобензол (краситель анилиновый желтый) применяется в производстве более сложных промежуточных продуктов, красителей, химических добавок к полимерам, фармацевтических препаратов, пестицидов и др. 4-Аминоазобензол является доступным исходным соединением для получения на его основе перспективных соединений для создания оптических материалов. Взаимодействием 4-аминоазобензола с альдегидами ванилинового ряда в среде кипящего абсолютного метанола в присутствии каталитических количеств ледяной уксусной кислоты были синтезированы (E,E)-азоазометины с выходами 75–88 %.

СИНТЕЗ (E,E)-АЗОМЕТИНОКСИМОВ НА ОСНОВЕ ОКСИМА 4-АМИНОАЦЕТОФЕНОНА

4-Aminoacetophenone oxime is convenient and accessible reagent for chemical modification of substituted aromatic aldehydes to produce ligands for complexation with transition metals. By the reaction of 4-aminoacetophenone oxime with aldehydes vanillyl series by boiling in absolute methanol in the presence of catalytic amounts of glacial acetic acid, (E,E)-azomethyneoximes with 70–85 % yields were synthesized. By the reaction of 4-aminoacetophenone oxime with 9-phenanthrene carboxaldehyde, ferrocene carboxaldehyde, 5-phenylisoxazole-3-carboxaldehyde and 5-(p-tolyl)isoxazole- 3-carboxaldehyde, corresponding (E,E)-azomethineoximes with 77–84 % yield were obtained. By acylation of the (E)-1-{4-(E)-benzo[d][1,3]dioxol-5-ylmethyleneaminophenyl}ethan-1-one oxime in a solution of dry diethyl ester in the presence of triethylamine, corresponding ester was synthesized with 84 % yield. By quantum chemical calculations using DFT method using level B3LYP1 / MIDI using the theory GAMESS software package and a MIDI basic set, we defined the most thermodynamically stable isomers of the synthesized compounds. In the process of calculations a full optimization of all geometric parameters to achieve a minimum total energy (E,E)-, (E,Z)-, (Z,E)- and (Z,Z)-azomethineoximes was carried out.Оксим 4-аминоацетофенона является удобным и доступным реагентом для химической модификации замещенных ароматических альдегидов с целью получения лигандов для комплексообразования с переходными металлами. Взаимодействием оксима 4-аминоацетофенона с альдегидами ванилинового ряда, в среде кипящего абсолютного метанола в присутствии каталитических количеств ледяной уксусной кислоты были синтезированы (E,E)-азометины с выходами 70–85 %. Взаимодействием 4-аминоацетофенона с 9-фенантренкарбальдегидом, ферроценкарбальдегидом, 5-фенилизоксазол-3-карбальдегидом и 5-(п-толил)изоксазол-3-карбальдегидом были получены соответствующие (E,E)-азометиноксимы c выходом 77–84 %. Ацилированием оксима (E)-1-{4-(E)-бензо[d][1,3]диоксол-5-илметиленаминофенил}этан-1-она хлорангидридом 4,5-дихлоризотиазол-3-карбоновой кислоты в растворе сухого диэтилового эфира в присутствии триэтиламина был синтезирован соответствующий сложный эфир с вы- ходом 84 %. Путем квантово-химических расчетов с использованием метода DFT с применением уровня теории B3LYP1/MIDI, программного пакета GAMESS и базисного набора MIDI установлены наиболее термодинамически устойчивые изомеры ряда синтезированных соединений. При расчетах проводили оптимизацию всех геометрических параметров до достижения минимумов полных электронных энергий (E,E)-, (E,Z)-(Z,E)- и (Z,Z)-азометиноксимов

Synthesis, antitubercular activity and mechanism of resistance of highly effective thiacetazone analogues

Defining the pharmacological target(s) of currently used drugs and developing new analogues with greater potency are both important aspects of the search for agents that are effective against drug-sensitive and drug-resistant Mycobacterium tuberculosis. Thiacetazone (TAC) is an anti-tubercular drug that was formerly used in conjunction with isoniazid, but removed from the antitubercular chemotherapeutic arsenal due to toxic side effects. However, several recent studies have linked the mechanisms of action of TAC to mycolic acid metabolism and TAC-derived analogues have shown increased potency against M. tuberculosis. To obtain new insights into the molecular mechanisms of TAC resistance, we isolated and analyzed 10 mutants of M. tuberculosis that were highly resistant to TAC. One strain was found to be mutated in the methyltransferase MmaA4 at Gly101, consistent with its lack of oxygenated mycolic acids. All remaining strains harbored missense mutations in either HadA (at Cys61) or HadC (at Val85, Lys157 or Thr123), which are components of the bhydroxyacyl-ACP dehydratase complex that participates in the mycolic acid elongation step. Separately, a library of 31 new TAC analogues was synthesized and evaluated against M. tuberculosis. Two of these compounds, 15 and 16, exhibited minimal inhibitory concentrations 10-fold lower than the parental molecule, and inhibited mycolic acid biosynthesis in a dose-dependent manner. Moreover, overexpression of HadAB HadBC or HadABC in M. tuberculosis led to high level resistance to these compounds, demonstrating that their mode of action is similar to that of TAC. In summary, this study uncovered new mutations associated with TAC resistance and also demonstrated that simple structural optimization of the TAC scaffold was possible and may lead to a new generation of TAC-derived drug candidates for the potential treatment of tuberculosis as mycolic acid inhibitors