150 research outputs found

    Circulating Atherogenic Multiple-Modified Low-Density Lipoprotein: Pathophysiology and Clinical Applications

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    Low-density lipoprotein (LDL) circulating in human bloodstream is the source of lipids that accumulate in arterial intimal cells in atherosclerosis. In-vitro–modified LDL (acetylated, exposed to malondialdehyde, oxidized with transition metal ions, etc.) is atherogenic, that is, it causes accumulation of lipids in cultured cells. We have found that LDL circulating in the atherosclerosis patients’ blood is atherogenic, while LDL from healthy donors is not. Atherogenic LDL was found to be desialylated. Moreover, only the desialylated subfraction of human LDL was atherogenic. Desialylated LDL is generally denser, smaller, and more electronegative than native LDL. Consequently, these LDL types are multiply modified, and according to our observations, desialylation is probably the principal and foremost cause of lipoprotein atherogenicity. It was found that desialylated LDL of coronary atherosclerosis patients was also oxidized. Complex formation further increases LDL atherogenicity, with LDL associates, immune complexes with antibodies recognizing modified LDL and complexes with extracellular matrix components being most atherogenic. We hypothesized that a nonlipid factor might be extracted from the blood serum using a column with immobilized LDL. This treatment not only allowed revealing the nonlipid factor of blood atherogenicity but also opened the prospect for reducing atherogenicity in patients

    Вплив антіадгезивних агентів на перитонеальні спайки в експерименті

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    Незважаючи на впровадження сучасних матеріалів і мініінвазивних оперативних технологій, хірургічне лікування спайкової кишкової непрохідності становить 2% від усіх лапаротомій. Мета: вивчити вплив антіадгезивних агентів на розвиток перитонеальних спайок в експерименті. Об'єктом були 42 статевозрілі щури лінії Вістар масою 200-250 г. Тварини були розділені на 3 групи (А, В, С) в залежності від складу ААГ і способу його аплікації, контрольну групу склали 7 щурів

    Scaling and Crossover to Tricriticality in Polymer Solutions

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    We propose a scaling description of phase separation of polymer solutions. The scaling incorporates three universal limiting regimes: the Ising limit asymptotically close to the critical point of phase separation, the "ideal-gas" limit for the pure-solvent phase, and the tricritical limit for the polymer-rich phase asymptotically close to the theta point. We have also developed a phenomenological crossover theory based on the near-tricritical-point Landau expansion renormalized by fluctuations. This theory validates the proposed scaled representation of experimental data and crossover to tricriticality.Comment: 4 pages, 3 figure

    Self-assembly of phosphate fluorosurfactants in carbon dioxide

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    Anionic phosphodiester surfactants, possessing either two fluorinated chains (F/F) or one hydrocarbon chain and one fluorinated chain (H/F), were synthesized and evaluated for solubility and self-assembly in liquid and supercritical carbon dioxide. Several surfactants, of both F/F and EUF types and having varied counterions, were found to be capable of solubilizing water-in-CO2 (W/C), via the formation of microemulsions, expanding upon the family of phosphate fluorosurfactants already found to stabilize W/C microemulsions. Small-angle neutron scattering was used to directly characterize the microemulsion particles at varied temperatures, pressures, and water loadings, revealing behavior consistent with previous results on W/C microemulsions

    Effect of glucocorticoids on bone metabolism in replacement therapy of adrenal insufficiency. Literature review

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    Adrenal insufficiency (AI) is a syndrome caused by disturbance in the synthesis and secretion of hormones of the adrenal cortex, which ensure the vital activity, energy and water-salt homeostasis. The widest hormonal deficiency is observed in primary hypocorticism, when the synthesis of not only glucocorticoids (GC) and adrenal androgens, but also mineralocorticoids is disrupted. Lifelong replacement therapy with GCs for this pathology may be associated with a risk of bone loss and osteoporosis. However, at present, there are no clear guidelines for diagnosis of bone condition, including and bone mineral density (BMD) monitoring during treatment with GCs in patients with AI. This review summarizes collected data on the key pathogenetic links of glucocorticoid-induced osteoporosis, incidence of decreased BMD and fractures in patients with AI. In this review factors that influence bone metabolism in this cohort of patients are considered: the type and the dose of prescribed GCs, the type (primary, secondary, HH in congenital adrenal cortex dysfunction) and the duration of AI, age, gender, and the presence of concomitant endocrine disorders (hypogonadism, growth hormone (GH) deficiency). In addition, the review presents data on the effect of adrenal androgen replacement therapy and recombinant GH therapy on bone metabolism in secondary AI

    Probing structural relaxation in complex fluids by critical fluctuations

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    Complex fluids, such as polymer solutions and blends, colloids and gels, are of growing interest in fundamental and applied soft-condensed-matter science. A common feature of all such systems is the presence of a mesoscopic structural length scale intermediate between atomic and macroscopic scales. This mesoscopic structure of complex fluids is often fragile and sensitive to external perturbations. Complex fluids are frequently viscoelastic (showing a combination of viscous and elastic behaviour) with their dynamic response depending on the time and length scales. Recently, non-invasive methods to infer the rheological response of complex fluids have gained popularity through the technique of microrheology, where the diffusion of probe spheres in a viscoelastic fluid is monitored with the aid of light scattering or microscopy. Here we propose an alternative to traditional microrheology that does not require doping of probe particles in the fluid (which can sometimes drastically alter the molecular environment). Instead, our proposed method makes use of the phenomenon of "avoided crossing" between modes associated with the structural relaxation and critical fluctuations that are spontaneously generated in the system.Comment: 4 pages, 4 figure

    The course of gout in a patient with Cushing’s disease after successful surgical treatment

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    Endogenous  hypercortisolism  is a severe endocrine  disease characterized by prolonged  exposure to excessive amounts of glucocorticoid hormones, accompanied by a wide range of symptoms and complications, including immunosuppression. Timely surgical treatment in most cases allows to save the patient’s life, significantly improve its quality. However, restoration of the normal concentration of glucocorticoid  hormones can become a trigger factor in the development or exacerbation of autoimmune and auto-inflammatory diseases. We present a clinical case of atypical gout in a patient with hypercortisolism and a progressive increase in symptoms of the disease after successful surgical treatment for Cushing’s disease and achieving stable remission. The issues of diagnosis and treatment of this group of autoinflammatory diseases are highlighted, the leading clinical and radiological  symptoms are considered, the differential diagnosis  of microcrystalline (metabolic) arthritis is presented. Despite the widespread, the diagnosis and treatment of this group of diseases still cause difficulties for specialists. A competent choice of drug therapy allows to fully control diseases considered in the article, including when they are combined, and thereby improve the quality of life of the patient

    Draft of Russian Clinical Practice Guidelines «Male hypogonadism»

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    Hypogonadism in males, defined as a decrease in serum testosterone levels in combination with characteristic symptoms and/or signs, can be observed with pathological changes in the testicles and/or pituitary gland, such as Klinefelter’s syndrome, Kallman’s syndrome, as well as in men with metabolic (obesity, diabetes mellitus) or iatrogenic disorders leading to a decrease in androgen production. The draft guidelines cover the extensive range of pathologies that cause hypogonadism development (testosterone deficiency) and focus on its clinical variants, which make up the majority of cases of hypogonadism observed in men. The authors and reviewers are an interdisciplinary group of experts, consisting of endocrinologists, andrologists, urologists - members of the «Russian Association of Endocrinologists» and «Men’s and Reproductive Health» public organizations.Clinical guidelines contain the most reliable evidence available to experts at the time of writing. Nevertheless, recommendations cannot replace clinical experience, and deciding on the start of treatment, choosing a method of therapy, or a drug should always consider the individual characteristics of a specific patient

    Синтез та деякі перетворення алкіл N-(2-арил-3-нітро-1,1,1-трифторопропан-2-іл)карбаматів

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    The paper is devoted to preparation and study of the transformations of novel multifunctional fluorinated synthetic building blocks – alkyl N-(3-nitro-1,1,1-trifluoropropan-2-yl) carbamates. In order to obtain them in high yields the aza-Henry reaction of 2,2,2-trifluoroethylidencarbamates with nitromethane catalyzed by triethylamine has been proposed. The structure of the compounds obtained has been confirmed by spectral methods. Essential elements of the structure corroboration are 13C NMR spectra, in which a signal of the newly formed stereogenic carbon atom is found as a quartet at 63 ppm. It has been shown that the interaction of sodium borohydride with alkyl N-(3-nitro-1,1,1-trifluoropropan-2-yl)carbamates in the presence of the equimolar amount of NiCl2.6H2O leads to selective reduction of the nitro group and formation of the corresponding alkyl N-(3-aminopropan-2-yl)carbamates. The presence of amino group in their structure considerably affects the chemical shifts of diastereotopic methylene protons. Their signals in the 1H NMR spectra are upfield (about 2 ppm difference in comparison with nitro derivatives). Alkyl N-(3-aminopropan-2-yl)carbamates in refluxing toluene in the presence of DBU were easily transformed into 4-trifluorometylimidazolidyn-2-ones by intramolecular cyclization. In its turn, tert-butyl N-(3-aminopropan-2-yl)carbamates when treating with hydrogen chloride in dioxane readily gave 3,3,3-trifluoropropan-1,2-diamines through Boc protecting group cleavage.Работа посвящена получению и исследованию преобразований новых полифункциональных фторсодержащих синтез-блоков – алкил N-(3-нитро-1,1,1-трифторопропан-2-ил)карбаматов. Для их получения предложена катализируемая триэтиламином реакция аза-Генри 2,2,2-трифтороэтилиденкарбаматов с нитрометаном. Строение синтезированных соединений надежно подтверждено комплексом спектральных методов, среди которых наиболее доказательными являются спектры ЯМР 13С, в которых новообразованный стереогенный атом углерода фиксируется в виде квартета при 63 м.д. Показано, что при воздействии на алкил N-(3-нитро-1,1,1-трифторопропан-2-ил)карбаматы боргидрида натрия в присутствии эквимолярного количества NiCl2.6H2O происходит селективное восстановление нитрогруппы и образование соответствующих алкил N-(3-аминопропан-2-ил)карбаматов. Наличие в их структуре аминогруппы существенно сказывается на химических сдвигах диастереотопных метиленовых протонов, которые в спектрах ЯМР 1Н смещены в область сильного поля примерно на 2 м.д. по сравнению с нитропроизводными. N-(3-Аминопропан-2-ил)карбаматы при кипячении в толуоле в присутствии ДБУ подвергаются внутримолекулярной циклизации в 4-трифторометилимидазолидин-2-оны. В свою очередь, при обработке трет-бутил (3-аминопропан-2-ил)карбаматов хлористым водородом в диоксане происходит легкое снятие защитной Boc-группы и образование 3,3,3-трифторопропан-1,2-диаминов.Робота присвячена отриманню та дослідженню перетворень нових поліфункціональних фторовмісних синтез-блоків – алкіл N-(3-нітро-1,1,1-трифторопропан-2-іл)карбаматів. Для їх одержання запропонована каталізована триетиламіном реакція аза-Генрі 2,2,2-трифтороетиліденкарбаматів із нітрометаном. Структура синтезованих сполук надійно доведена комплексом спектральних методів, серед яких найбільш доказовими є спектри ЯМР 13С, в яких новоутворений стереогенний атом вуглецю фіксується у вигляді квартету при 63 м.ч. Показано, що при дії на алкіл N-(3-нітро-1,1,1-трифторопропан- 2-іл)карбамати борогідриду натрію в присутності еквімолярної кількості NiCl2.6H2O відбувається селективне відновлення нітрогрупи і утворення відповідних алкіл N-(3-амінопропан-2-іл)карбаматів. Наявність в їх структурі аміногрупи суттєво позначається на хімічних зсувах діастереотопних метиленових протонів, які в спектрах ЯМР 1Н зміщені в область сильного поля приблизно на 2 м.ч. порівняно з нітропохідними. Алкіл N-(3-амінопропан-2-іл)карбамати при кип’ятінні в толуолі в присутності ДБУ піддаються внутрішньомолекулярній циклоконденсації в 4-трифторометилімідазолідин-2-они. В свою чергу, при обробці трет-бутил N-(3-амінопропан-2-іл)карбаматів хлороводнем у діоксані спостерігається легке зняття захисної Boc-групи і утворення 3,3,3-трифторопропан-1,2-діамінів
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