Identification of Phylogenetic Position in the Chlamydiaceae Family for Chlamydia Strains Released from Monkeys and Humans with Chlamydial Pathology

Based on the results of the comparative analysis concerning relatedness and evolutional difference of the 16S–23S nucleotide sequences of the middle ribosomal cluster and 23S rRNA I domain, and based on identification of phylogenetic position for Chlamydophila pneumoniae and Chlamydia trichomatis strains released from monkeys, relatedness of the above stated isolates with similar strains released from humans and with strains having nucleotide sequences presented in the GenBank electronic database has been detected for the first time ever. Position of these isolates in the Chlamydiaceae family phylogenetic tree has been identified. The evolutional position of the investigated original Chlamydia and Chlamydophila strains close to analogous strains from the Gen-Bank electronic database has been demonstrated. Differences in the 16S–23S nucleotide sequence of the middle ribosomal cluster and 23S rRNA I domain of plasmid and nonplasmid Chlamydia trachomatis strains released from humans and monkeys relative to different genotype groups (group B-B, Ba, D, Da, E, L1, L2, L2a; intermediate group-F, G, Ga) have been revealed for the first time ever. Abnormality in incA chromosomal gene expression resulting in Chlamydia life development cycle disorder, and decrease of Chlamydia virulence can be related to probable changes in the nucleotide sequence of the gene under consideratio

Cerium Binding Activity of Pectins Isolated from the Seagrasses Zostera marina and Phyllospadix iwatensis

Cerium binding activity of three different water soluble pectin compounds of different origin was studied in a batch sorption system. The Langmuir, Freundlich and BET sorption models were adopted to describe the binding reactions between metal ions and pectin molecules. The Langmuir model provided the best fit. Within the pH range from 4.0 to 6.0, the largest amount of the cerium ions was bound by pectin isolated from the seagrass Phylospadix iwatensis in comparison to pectin extracted from the seagrass Zostera marina and pectin obtained from citrus peel (commercial grade). The Langmuir constants were also highest for the pectin samples isolated from the seagrass P. iwatensis. The results obtained from this study suggest that pectin is a prospective source for the development of radioisotope-removing pharmaceuticals

МР-томография миокарда с парамагнитным контрастным усилением Mn-етоксиизобутилизонитрилом (Mn-МИБИ) в эксперименте

Aim: to evaluate with MRI technique the uptake of paramagnetic complex Mn-methoxyisobutylisonitrile (MIBI) to myocardium in rats in normal control animals and in experimental infarction. Material and methods. Complex Mn-MOBI was obtained with one-stage synthesis from manganese (II) carbonate and methoxyisobutylisonitrile hydroxide (produced by the Laboratory of technology and control of radiopharmaceuticals of the A.I. Burnazyan Russian state federal medical and biophysics Center), obtaining finally the 0.5 M solution of Mn-MIBI at pH = 6.3. The Mn-MIBI was injected intravenously slowly to sleeping rats (Telazol, i/m), as 0.05 ml of 0,5 M solution per Kg of BW. For this study nine normal control Whistar rats were employed as well as ten animals with previously induced anterior myocardial infarction of the left ventricle (all males). MRI scanning in T1-weighted spin-echo has been carried out with TR = 500 ms and TE = 15 ms, in axial and frontal slices as thin as 2-2.5 mm, to the matrix 256 х 256, with the field of view as large as 200 х 200 mm. The uptake was scored visually as change in intensity of T1-weighted MRI frontal scans of the whole body of the animals, of axial scans of chest and heart; and also quantitatively, with calculating for the T1-weighted MRI the index of enhancement (IE) of intensity per voxel, as : IE = (MeanInt of T1-w.MRI)Mn-MIBI / (MeanInt of T1-w.MRI)initial Results. Visually on whole-body T1-weighted SE frontal scans the MN-MIBI induced increase of intensity of the heart image, essentially equal for all parts of the left ventricle and less intense over the right ventricle. The values of the IE were over 2.5 for all parts of the left ventricle, whereas only 1.8-1.9 in case of the septum. IE of the right ventricle did not differ significantly when compared to the LV values. When injected to animals with experimental myocardial infarction the Mn-MIBI did not induced any essential changes of intensity in non-perfused regiones, with IE = 1.19 ± 0. 08, but raised the intensity over intact lateral wall of the left ventricle, with IE = 2.65 ± 0.14, and also over intact anterior wall, with IE = 2.28 ± 0.17. Conclusion. Complexonate Mn-MIBI provides well enough intense enhancement of myocardium in T1-SE MRI and makes possible to image severe disorders of myocardial blood flow in experimental models. The Mn-MIBI complex can be suggested as basic molecule for nearest future design of paramagnetic contrast agents for myocarrdial perfusion imaging, as well as for other organs taking up the MIBI. Manganese also is conceivable to be employed for labelling of other complexones currently in use in nuclear medicine.Цель исследования: попытка оценки по данным МРТ накопления парамагнитного комплекса Mn-метоксиизобутилизонитрила (МИБИ) в миокарде у крыс в норме и при экспериментальном инфаркте. Материал и методы. Комплекс Mn с МИБИ был получен в один этап из карбоната марганца (II) и гидроксида метоксиизобутилизонитрила (синтезированного лабораторией технологий и методов контроля радиофармпрепаратов ГНЦ России - ФМБЦ им. А.И. Бурназяна) с выходом в итоге 0,5 М раствора Mn-МИБИ при pH 6,3. Препарат Mn-МИБИ вводился внутривенно медленно из расчета 0,05 мл 0,5 М раствора на 1 кг массы тела. В исследование включено 9 контрольных белых крыс и 10 (все самцы) с предварительно смоделированным инфарцированием передней стенки сердца. Сканирование в Т1-взвешенном спин-эхо выполнено до и спустя 8-10 мин после введения Mn-МИБИ при TR 500 мс и TE 15 мс в аксиальных и сагиттальных плоскостях при толщине среза 2-2,5 мм в матрицу 256 х 256 и при размерах поля сканирования 200 х 200 мм. Оценивалались визуальные изменения картины Т1-взвешенной МРТ всего тела и, в частности, сердца, а также количественно степень усиления интенсивности Т1-взвешенного спин-эхо МРТ, как: ИУ = (средн.инт. Т1-взв. МРТ)Mn-МИБИ/ (средн.инт. Т1-взв. МРТ)исходи. Результаты. Визуально отмечалось усиление интенсивности Т1- взвешенного спин-эхо-изображения МРТ в области миокарда левого желудочка в одинаковой степени по всем отделам левого желудочка и визуально меньше - в области правого желудочка. Интенсивность Т1-взвешенных изображений стенок левого желудочка усиливалась в 2,5 раза и более, тогда как в области перегородки - в 1,8-1,9 раза, т.е. достоверно меньше. Индекс усиления правого желудочка не отличался от значений для миокарда левого желудочка. При исследовании у животных с инфарктом миокарда усиление в области инфаркта визуально было незначительным; при количественной оценке индекса усиления для инфарцированных отделов составил 1,19 ± 0,08, в неповрежденной боковой стенке - 2,65 ± 0,14, в неповрежденной передней - 2,28 ± 0,17. Вывод. Комплекс Mn-МИБИ обеспечивает достаточно интенсивное усиление изображение миокарда при МРТ в Т1-взвешенном спин-эхо-режиме и позволяет визуализировать грубые нарушения кровоснабжения сердечной мышцы в эксперименте. Комплекс Mn-МИБИ может рассматриваться как основа для создания парамагнитных контрастных препаратов для визуализации миокарда и, вероятно, также других органов и структур, где было отмечено накопление метоксиизобутилизонитрила. Предполагается использовать комплексонаты99mTc как основу для аналогичных комплексонатов Mn, если их стабильность и R1-релаксивность окажутся достаточными для парамагнитного контрастирования в МР

Service Provider Competition: Delay Cost Structure, Segmentation, and Cost Advantage

We model competition between two providers who serve delay-sensitive customers. We compare a generalized delay cost structure, where a customer's delay cost depends on her service valuation, with the traditional additive delay cost structure, where the delay cost is independent of the customer's service valuation. Under the additive delay cost structure, service providers offer different prices and expected delays, but customers are indifferent between the providers. Under the generalized delay cost structure, when the providers have different capacity or operating costs, we obtain value-based market segmentation, whereby higher-value customers choose one provider and lower-value customers choose the other. We study how the delay cost parameters, the market size, and the service providers' costs affect the structure of the equilibrium.delay cost structure, value-based market segmentation, service competition