172 research outputs found
Spectral Analysis of Structural Changes of the Heart Valves at Different Stages of Their Decellularization
Presents the results of applying the method of Raman spectroscopy for the qualitative analysis of the surfaces of the heart valve of sheep before and during their decellularization. Optical analysis showed that the implementation of decellularization valves reduces the content of glycosaminoglycans, proteins and lipids. Found that using specified optical coefficients, it is possible to control the efficiency of the process of decellularization heart valves.
Keywords: Raman spectroscopy, heart valve, optical coefficient, decellularization, spectral analysis
The application of the Raman Spectroscopy Method for Evaluating Implants from the Dura Mater
The results of a comparative spectral evaluation of the component composition of the surfaces of implants from the dura mater manufactured using the Lioplast technology with the use of ultrasound and sterilization are presented. Based on the analysis, coefficients were introduced reflecting the change in the relative concentration of components that determine the quality of the implants. It is established that Raman spectroscopy can be used to assess the change in the composition of implants based on the dura mater during their manufacture.
Keywords: Raman spectroscopy, coefficients, spectral features, implants, dura mater
Spectral Studies of Rat Bone Tissue in Modeling Osteoporosis and Effectiveness of Treatment By Hydroxyapatite
Presents the result of experiments on the study of the model of osteoporosis in rats using Raman spectroscopy and the effectiveness of its treatment with hydroxyapatite. Were revealed spectral differences between groups of samples (control group, group with the model of osteoporosis and a group with the model of osteoporosis after treatment with hydroxyapatite). In addition, optical coefficients were introduced to evaluate the effectiveness of treatment.
Keywords: Raman spectroscopy, optical coefficients, osteoporosis, hydroxyapatite, collagen matri
Вплив розподілу мометазону фуроату в емульсіях на його протизапальну дію
Aim. To study distribution of mometasone furoate (MF) in emulsions of the 1st (o/w) and 2nd (w/o) types with different excipients, as well as to conduct a comparative experimental study of the anti-inflammatory effect of 0.1 % creams of MF with these emulsions as a vehicle.Materials and methods. When studying its solubility, distribution between phases and solubilization by surfactant micelles the method of liquid chromatography was used for assay of MF; optical microscopy was used for determination of the disperse system type. The anti-inflammatory activity was studied on the dextran-induced rat paw edema and aerosol-induced rat paw edema.Results. The solubility of MF in various hydrophilic and lipophilic solvents, distribution between the liquid paraffin and the hydrophilic solvent hexylene glycol–water (8:2), as well as solubilization by micelles of surfactants have been studied, it allows to predict the disperse state, distribution and localization of MF in emulsions of type 1 and 2, which are the vehicles for soft dosage forms. The dispersed state of MF in emulsions of type 1 and 2 has been confirmed by optical microscopy. The anti-inflammatory activity of 0.1 % Mometasone cream (a vehicle – o/w emulsion where MF is mostly in the form of a suspension) and 0.1 % Elocom® cream (a vehicle – w/o emulsion where MF is mostly dissolved in a dispersed hydrophilic phase) was studied. It has been determined that the dynamics of the anti-inflammatory effects (AE) for both drugs differs depending on the type of inflammatory edema; however, both drugs compared have a similar dynamics of AE under conditions of the same edema. It indicates that the type and concentration of glucocorticosteroid is a determining pharmaceutical factor for AE dynamic. Under conditions of the dextran-induced rat paw edema there is a pronounced tendency towards a higher AE in case of 0.1 % Mometasone cream (a vehicle – o/w emulsion) compared to 0.1 % Elocom® cream (a vehicle – w/o emulsion). It indicates the impact of differences in the pharmaceutical factors of these drugs on the efficiency of their anti-inflammatory activity. In the conditions of an aerosol-induced rat paw edema AE of 0.1 % Mometasone cream (a vehicle – o/w emulsion) basically corresponds to AE of 0.1 % Elocom® cream (a vehicle – w/o emulsion).Conclusions. According to the results of the research the cream with MF and the o/w emulsion as a vehicle should be used in the acute phase of the inflammatory process accompanied with exudation, while the cream or ointment with the w/o emulsion as a vehicle – for the treatment of chronic dermatoses accompanied with a dry skin.Цель работы. Исследование возможного распределения мометазона фуроата (МФ) в эмульсиях 1 и 2 рода с разным составом вспомогательных веществ, а также сравнительное экспериментальное изучение противовоспалительного действия 0,1 % кремов МФ на основе таких эмульсий.Материалы и методы. Для количественного определения МФ при изучении его растворимости, распределения между фазами и солюбилизации мицеллами ПАВ использовали метод жидкостной хроматографии, а для определения типа дисперсной системы – метод оптической микроскопии. Эффективность противовоспалительного действия препаратов исследовали на моделях декстранового и аэросильного воспаления стопы крыс.Результаты. Исследована растворимость МФ в различных гидрофильных и липофильных растворителях, распределение между вазелиновым маслом и гидрофильным растворителем гексиленгликоль – вода (8:2) и солюбилизация мицеллами ПАВ, что позволяет прогнозировать дисперсное состояние, распределение и локализацию МФ в эмульсиях 1 и 2 рода, являющихся основами для мягких лекарственных средств. Дисперсное состояние МФ в эмульсиях 1 и 2 рода подтверждено методом оптической микроскопии. Исследована эффективность противовоспалительного действия препаратов Мометазон крем 0,1 % на основе эмульсии 1 рода, в которой МФ находится преимущественно в виде суспензии, и препарата Элоком® крем 0,1 % на основе эмульсии 2 рода, в которой МФ находится в виде раствора в дисперсной гидрофильной фазе. Установлено, что динамика противовоспалительных эффектов (ПЭ) для обоих препаратов отличается в зависимости от типа воспалительного отёка, однако сравниваемые препараты характеризуются сходной динамикой ПЭ в условиях одного и того же отёка. Это свидетельствует о том, что определяющим фармацевтическим фактором для динамики ПЭ является тип и концентрация глюкокортикостероида. При декстрановом воспалении наблюдается выраженная тенденция к более высокому ПЭ препарата Мометазон крем 0,1 % на основе эмульсии 1 рода сравнительно с препаратом Элоком® крем 0,1 %, что свидетельствует о влиянии различий в фармацевтических факторах этих препаратов на эффективность их противовоспалительного действия. В условиях более длительного (аэросильного) воспаления препарат Мометазон крем 0,1 % на основе эмульсии 1 рода оказывает ПЭ, который в целом соответствует ПЭ препарата Элоком® крем 0,1 % на основе эмульсии 2 рода.Выводы. По результатам исследований крем с МФ на основе эмульсии 1 рода следует применять в острой фазе воспалительного процесса, сопровождающейся экссудацией, а крем или мазь на основе эмульсии 2 рода – при хронических дерматозах, сопровождающихся сухостью кожи. Мета роботи. Дослідження можливого розподілу мометазону фуроату (МФ) в емульсіях 1 і 2 роду з різним складом допоміжних речовин, а також порівняльне експериментальне вивчення протизапальної дії 0,1 % кремів МФ на основі таких емульсій.Матеріали та методи. Для кількісного визначення МФ при вивченні його розчинності, розподілу між фазами і солюбілізації міцелами ПАР використовували метод рідинної хроматографії, а для визначення типу дисперсної системи – метод оптичної мікроскопії. Ефективність протизапальної дії препаратів досліджували на моделях декстранового і аеросильного запалення стопи щурів.Результати. Досліджено розчинність МФ в різних гідрофільних і ліпофільних розчинниках, розподіл між вазеліновим маслом і гідрофільним розчинником гексиленгліколь – вода (8:2) і солюбілізацію міцелами ПАР, що дозволяє прогнозувати дисперсний стан, розподіл і локалізацію МФ в емульсіях 1 і 2 роду, які є основами для м’яких лікарських засобів. Дисперсний стан МФ в емульсіях 1 і 2 роду підтверджено методом оптичної мікроскопії. Досліджено ефективність протизапальної дії препаратів Мометазон крем 0,1 % на основі емульсії 1 роду, де МФ знаходиться переважно у вигляді суспензії, і препарату Елоком® крем 0,1 % на основі емульсії 2 роду, де МФ знаходиться у вигляді розчину в дисперсній гідрофільній фазі. Встановлено, що динаміка протизапальних ефектів (ПЕ) для обох препаратів відрізняється у залежності від типу запального набряку, однак порівнювані препарати характеризуються подібною динамікою ПЕ в умовах однакового набряку. Це свідчить про те, що визначальним фармацевтичним фактором для динаміки ПЕ є тип і концентрація глюкокортикостероїду. При декстрановому запаленні спостерігається виражена тенденція до більш високого ПЕ препарату Мометазон крем 0,1 % на основі емульсії 1 роду порівняно з препаратом Елоком® крем 0,1 %, що свідчить про вплив відмінностей у фармацевтичних факторах цих препаратів на ефективність їх протизапальної дії. В умовах більш тривалого (аеросильного) запалення препарат Мометазон крем 0,1 % на основі емульсії 1 роду виявляє ПЕ, який в цілому відповідає ПЕ препарату Елоком® крем 0,1 % на основі емульсії 2 роду.Висновки. За результатами досліджень крем з МФ на основі емульсії 1 роду слід застосовувати в гострій фазі запального процесу, що супроводжується ексудацією, а крем або мазь на основі емульсії 2 роду – при хронічних дерматозах, що супроводжуються сухістю шкіри
Two distinct nanovirus species infecting faba bean in Morocco
Using monoclonal antibodies raised against a Faba bean necrotic yellows virus (FBNYV) isolate from Egypt and a Faba bean necrotic stunt virus (FBNSV) isolate from Ethiopia, a striking serological variability among nanovirus isolates from faba bean in Morocco was revealed. To obtain a better understanding of this nanovirus variability in Morocco, the entire genomes of two serologically contrasting isolates referred to as Mor5 and Mor23 were sequenced. The eight circular ssDNA components, each identified from Mor5- and Mor23-infected tissues and thought to form the complete nanovirus genome, ranged in size from 952 to 1,005 nt for Mor5 and from 980 to 1,004 nt for Mor23 and were structurally similar to previously described nanovirus DNAs. However, Mor5 and Mor23 differed from each other in overall nucleotide and amino acid sequences by 25 and 26%, respectively. Mor23 was most closely related to typical FBNYV isolates described earlier from Egypt and Syria, with which it shared a mean amino acid sequence identity of about 94%. On the other hand, Mor5 most closely resembled a FBNSV isolate from Ethiopia, with which it shared a mean amino acid sequence identity of approximately 89%. The serological and genetic differences observed for Mor5 and Mor23 were comparable to those observed earlier for FBNYV, FBNSV, and Milk vetch dwarf virus. Following the guidelines on nanovirus species demarcation, this suggests that Mor23 and Mor5 represent isolates of FBNYV and FBNSV, respectively. This is the first report not only on the presence of FBNSV in a country other than Ethiopia but also on the occurrence and complete genome sequences of members of two nanovirus species in the same country, thus providing evidence for faba bean crops being infected by members of two distinct nanovirus species in a restricted geographic area
Interactive flow behaviour and heat transfer enhancement in a microchannel with cross flow synthetic jet
This paper examines the effectiveness in combining a pulsating fluid jet for thermal enhancement in microchannel heat sinks. The proposed arrangement utilises an oscillating diaphragm to induce a high-frequency periodic fluid jet with zero net mass output at the jet orifice hence, termed "synthetic jet". The pulsed jet interacts with the fluid flow through microchannel passages altering their flow characteristics. The present study develops a 2-dimensional finite volume numerical simulation based on unsteady Reynolds-averaged Navier-Stokes equations for examining the microchannel-synthetic jet flow interaction. For a range of parametric conditions, the behaviour of this periodic flow with its special features is identified and the associated convective heat transfer rates are predicted. The results indicate that the pulsating jet leads to outstanding thermal performance in microchannel flow increasing its heat dissipation rate by about 4.3 times compared to a microchannel without jet interaction within the tested parametric range. The degree of thermal enhancement is seen to grow continuously to reach a steady value in the absence of fluid compressibility. The proposed strategy has an intrinsic ability for outstanding thermal characteristics without causing pressure drop increases in microchannel fluid passages, which is identified as a unique feature of the technique.The study also examines and presents the effects of fluid compressibility on the heat removal capacity of this arrangement. The technique is envisaged to have application potential in miniature electronic devices where localised cooling is desired over a base heat dissipation load
CCAAT/Enhancer Binding Protein alpha uses distinct domains to prolong pituitary cells in the Growth 1 and DNA Synthesis phases of the cell cycle
BACKGROUND: A number of transcription factors coordinate differentiation by simultaneously regulating gene expression and cell proliferation. CCAAT/enhancer binding protein alpha (C/EBPα) is a basic/leucine zipper transcription factor that integrates transcription with proliferation to regulate the differentiation of tissues involved in energy balance. In the pituitary, C/EBPα regulates the transcription of a key metabolic regulator, growth hormone. RESULTS: We examined the consequences of C/EBPα expression on proliferation of the transformed, mouse GHFT1-5 pituitary progenitor cell line. In contrast to mature pituitary cells, GHFT1-5 cells do not contain C/EBPα. Ectopic expression of C/EBPα in the progenitor cells resulted in prolongation of both growth 1 (G1) and the DNA synthesis (S) phases of the cell cycle. Transcription activation domain 1 and 2 of C/EBPα were required for prolongation of G1, but not of S. Some transcriptionally inactive derivatives of C/EBPα remained competent for G1 and S phase prolongation. C/EBPα deleted of its leucine zipper dimerization functions was as effective as full-length C/EBPα in prolonging G1 and S. CONCLUSION: We found that C/EBPα utilizes mechanistically distinct activities to prolong the cell cycle in G1 and S in pituitary progenitor cells. G1 and S phase prolongation did not require that C/EBPα remained transcriptionally active or retained the ability to dimerize via the leucine zipper. G1, but not S, arrest required a domain overlapping with C/EBPα transcription activation functions 1 and 2. Separation of mechanisms governing proliferation and transcription permits C/EBPα to regulate gene expression independently of its effects on proliferation
CCAAT/enhancer binding proteins in normal mammary development and breast cancer
CCAAT/enhancer binding proteins (C/EBPs) are a family of leucine zipper, transcription factors that bind to DNA as homodimers and heterodimers. They regulate cellular proliferation, differentiation and apoptosis in the mammary gland. Multiple protein isoforms, including truncated, dominant negatives, are generated by translation of the C/EBPβ transcript or via proteolytic cleavage of the full-length C/EBPβ protein. Gene deletion of individual C/EBP family members has demonstrated an essential role for C/EBPβ in normal mammary development, while transgenic and overexpression studies provide evidence that the dominant-negative C/EBPβ-liver-enriched inhibitory protein isoform induces proliferation in mammary epithelial cells. Mounting evidence suggests that alterations in the ratio of the C/EBPβ-liver-enriched inhibitory protein isoform and the C/EBPβ-liver-enriched activating protein isoform may play a role in the development of breast cancer. This review will consequently focus on C/EBP actions in normal mammary development and on the emerging data that supports a role in breast cancer
The 5′ Flanking Region and Intron1 of the Bovine Prion Protein Gene (PRNP) Are Responsible for Negative Feedback Regulation of the Prion Protein
Transcription factors regulate gene expression by controlling the transcription rate. Some genes can repress their own expression to prevent over production of the corresponding protein, although the mechanism and significance of this negative feedback regulation remains unclear. In the present study, we describe negative feedback regulation of the bovine prion protein (PrP) gene PRNP in Japanese Black cattle. The PrP-expressing plasmid pEF-boPrP and luciferase-expressing plasmids containing the partial promoter fragment of PRNP incorporating naturally occurring single-nucleotide or insertion/deletion polymorphisms were transfected into N2a cells. Transfection of pEF-boPrP induced PrP overexpression and decreased the promoter activity of PRNP in the wild-type haplotype (23-bp Del, 12-bp Del, and −47C). Reporter gene assays further demonstrated that the 12- and 23-bp Ins/Del polymorphisms, which are thought to be associated with Sp1 (Specific protein 1) and RP58 (Repressor Protein with a predicted molecular mass of 58 kDa), in intron1 and the upstream region, respectively, and an additional polymorphism (−47C→A) in the Sp1-binding site responded differently to PrP overexpression. With the −47C SNP, the presence of the Del in either the 23-bp Ins/Del or the 12-bp Ins/Del allele was essential for the negative feedback caused by PrP overexpression. Furthermore, deletion mutants derived from the wild-type haplotype showed that nucleotides −315 to +2526, which include the 5′-flanking region and exon1, were essential for the response. These results indicate that certain negative feedback response elements are located in these sequences, suggesting that regulation by transcription factors such as Sp1 and RP58 may contribute to the negative feedback mechanism of PRNP
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