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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Efeitos do Bay 41-2272 na hipertensão pulmonar experimental em cães anestesiados / Effect of Bay 41-2272 in the pulmonary hypertension experimental in anesthetized dogs

Freitas, Cristiane Fonseca 23 February 2007 (has links)
Orientador: Edson Antunes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-09T08:05:23Z (GMT). No. of bitstreams: 1 Freitas_CristianeFonseca_D.pdf: 2119434 bytes, checksum: 58a318beb1d3946d852e010325a6187c (MD5) Previous issue date: 2007 / Resumo: Neste estudo, investigamos os efeitos protetores do BAY 41-2272 sobre a hipertensao pulmonar induzida pelo complexo heparina-protamina e hipoxia em cães anestesiados. Os animais foram anestesiados com pentobarbital sodico (Hypnol, 30mg/kg, iv) combinado com citrato de fentanila (0,01 mg/kg/h, i.v.) e diazepam (0,25mg/kg/h, iv). A hipertensao pulmonar pelo complexo heparina-protamina foi induzida com a administracao de 500 UI/kg de heparina, seguida da administracao de protamina (10 mg/kg). A interacao heparina-protamina causou aumento de aproximadamente 350% da pressao media da arteria pulmonar (PMAP), acompanhado de aumento significativo do indice de resistencia vascular pulmonar (IRVP) e da pressao capilar pulmonar (PcP). Este aumento foi significativo 2 min apos a injecao de protamina, mantendo-se significativamente elevado ate aproximadamente 5 minutos apos administracao da mesma. Ao mesmo tempo em que se detectou a hipertensao pulmonar, observamos reducao significativa da pressao arterial media (PAM). Observamos ainda um aumento significativo da frequencia cardiaca (FC) aos 2 minutos apos administracao da protamina com discreta diminuicao do indice cardiaco (IC). O indice de resistencia vascular sistemica (IRVS) nao sofreu alteracoes significativas. A saturacao do oxigenio (SpO2) foi significativamente diminuida apos a formacao do complexo heparina-protamina. Nos animais tratados com BAY 41-2272 (10 /kg/min, i.v.), observamos reducao marcante do aumento da PMAP, do IRVP e da PcP. Por outro lado, este tratamento potencializou a reducao da PAM. Alem disso, o BAY 41-2272 reduziu significantemente o IRVS e aumentou a FC. A diminuicao da SpO2 foi atenuada significativamente pelo BAY 41- 2272. Os niveis plasmaticos de GMPc foram dosados aos 2 min apos a formacao do complexo heparina-protamina, tendo-se mostrado elevados no grupo tratado com o BAY41-2272. O tempo de tromboplastina parcial ativado (TTPA) nao apresentou alteração significativa no tratamento com o BAY 41-2272. O veiculo do BAY 41-2272 (DMSO 30%) nao alterou significativamente os parametros estudados. A hipertensao pulmonar por hipoxia foi induzida com a instalacao de uma baixa tensao de oxigenio (FiO2=12%). Nesta circunstancia, a PMAP elevou-se em aproximadamente 280% aos 5 minutos, mantendo-se significativamente elevada ate 15 minutos apos instalacao da hipoxia. A elevacao da PMAP foi acompanhada de aumentos significativos no IRVP e PcP. A PAM, IRVS, FC e IC nao apresentaram alterações significativas. A SpO2 diminuiu na presenca da hipoxia. O tratamento com BAY 41-2272 (10 /kg/min, i.v.), reduziu significativamente a PMAP, PcP e IRVP. O IRVS foi significativamente potencializado pelo BAY 41-2272. A PAM, FC e IC nao alteraram significativamente. A diminuicao da SpO2 foi atenuada significativamente pelo BAY 41- 2272. Os niveis plasmaticos de GMPc elevaram-se significativamente no grupo tratado com o BAY 41-2272. Em conclusao, o BAY 41-2272 atenuou a acao vasoconstritora pulmonar induzida pelo complexo heparina-protamina e hipoxia levando a uma prevencao da hipertensao pulmonar. / Doutorado / Farmacologia / Doutor em Farmacologia
12

Stanovení protaminů kapilární zónovou elektroforézou / Capillary zone electrophoresis determination of protamines

Malý, Michal January 2015 (has links)
This work deals with development and optimization of a method for separation and detection of pro- tamines using capillary zone electrophoresis. The developed method uses a fused silica capillary with inner diameter of 50 µm and effective length of 41,5 cm. Driving voltage is 30 kV. Background electrolyte is aque- ous solution of 45 mmol dm−3 phosphoric acid. Analyte is detected spectrophotometrically at wavelength of 200 nm. Sample is injected hydrodynamically. The method allows for determination of protamines in the concentration range between 11 µg ml−1 to 1000 µg ml−1 , limit of detection is 4 µg ml−1 . Viablity of the method has been verified with a real sample of NPH insulin injection. For sufficiently sensitive detection of protamines in NPH insuline it is necessary to prepare the sample in acidic environment. For the pur- poses of this work the sample was acidified by addition of background electrolyte into the sample so that the background electrolyte concentration in the resulting solution of the sample was 18 mmol dm−3 . The main advantage of the method is the rapid analysis, migration time of the analyte is about 2 min. Disadvantage of the method in comparison to alternate methods using CZE or RP-HPLC is the inability to separate individ- ual protamine peptides. This disadvantage...
13

Cytochemical Studies of RNA and Basic Nuclear Proteins in Lycosid Spiders

Rasch, Ellen, Connelly, Barbara A. 01 December 2006 (has links)
Tissues of lycosid spiders were studied for RNA distributions with the basic dye Azure B. Changes in the basic proteins associated with DNA during spermiogenesis were identified with alkaline fast green staining after DNA extraction with trichloroacetic acid and by cytochemical tests for arginine. Tissue glycoproteins of the gut diverticula and the ducts of silk glands were resistant to diastase digestion and required periodic acid hydrolysis to localize reaction products with the Schiff reagent for aldehydes. Spiders possess novel types of cells that are in need of further study and may be useful as models for developmental biology.
14

Sperm Genetic and Epigenetic Mechanisms Regulating Male Fertility

Kutchy, Naseer Ahmad 08 December 2017 (has links)
Male fertility, ability to fertilize and activate the egg and support early embryo development, is crucial for mammalian reproduction and development. Testis specific histone 2B (TH2B) of sperm, protamines (PRM1/2), and posttranslational modifications of histone 3 (H3K27me3 and H3k27ac) are involved in spermatogenesis and male fertility. However, molecular and cellular mechanisms by which TH2B regulates histone to protamine replacement is poorly defined. Immunocytochemistry, western blotting, flow cytometry, computer-assisted sperm analysis (CASA) and bioinformatic approaches were applied to analyze sperm from Holstein bulls with different in vivo fertility. Results from the immunocytochemistry experiments showed that while TH2B and H3K27me3 were localized predominantly at the equatorial and post acrosomal (localized as a crown around the sperm head) parts, respectively. The H3K27ac was also detectable in the bovine sperm head. Signal intensities of TH2B (mean ± SEM) were higher in sperm from the low fertility bulls (220.56 ± 9.20) as compared to those from the high fertility bulls (198.39 ± 10.0). Signal intensities of H3K27me3 (16.25 ± 1.69) were significantly different than those of H3K27ac (4.74 ± 0.88) in bull spermatozoa. Using the bioinformatic tools, including Clustal Omega, Cytoscape, Emboss Dotmatcher, InterProScan, and STRING, we demonstrated that TH2B has the conserved histone H2B domain which has a strong association with proteins involved in chromosome organization and histone ubiquitination. Intensities of PRM1 and PRM2 were significantly associated with one another (p < 0.0001), but neither were significantly associated with fertility. Results from CASA revealed significant differences between high and low fertility bulls regarding average sperm pathway velocity, amplitude of lateral head displacement and straightness (p < 0.05). The interacting proteins of H3 are involved in subcellular processes such as regulation of H3K27 methylation, nucleosome assembly, regulation of DNA replication, and chromatin assembly. These results are significant because they help advance fundamental knowledge in sperm physiology involving epigenetic and genetic determinants. The new knowledge can be used to enhance reproductive biotechnology to improve fertility. In addition, the data generated using the unique bull model can be applied to study mammalian reproduction and development due to similarities in genetics and physiology between bovine and other mammals.
15

A double-stranded RNA binding protein that is important for murine spermatogenesis and growth /

Zhong, Jun, January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 109-133).
16

Vliv vybraných endocrinních disruptorů na reprodukční systém myších samců in vivo / Effect of selected endocrine disruptors on the male mouse reproductive system in vivo

Žatecká, Eva January 2015 (has links)
In our environment there are many compounds which can negatively influence humans and wildlife. Every day, a vast number of environmental pollutants are released into our environment and there is no way to avoid their exposure. Some of these compounds can even mimic endogenous hormones and interfere with our endocrine system (so called endocrine disruptors), which is the key regulatory system controlling almost all physiological processes in human and animal bodies. Also the reproductive system is largely regulated by various hormones, and their proper function is crucial for gamete formation, fertilization and embryo development. Environmental pollutants are therefore considered as one of the possible causes of increased infertility in human population. This prompted us to study the effect of two endocrine disruptors (tetrabromobisphenol A - TBBPA, and zearalenone - ZEA) on the male mouse reproductive system in vivo. According to our results, TBBPA is able to induce apoptosis as well as changes in the expression of selected testicular genes and sperm protamination. Our results also suggest that permanent exposure to TBBPA slightly enhances its effect in the next generation, depending on whether the parents have been affected or not. We hypothesized that differential protamination of the sperm DNA...
17

Self-assembled carrageenan/protamine polyelectrolyte nanoplexes-Investigation of critical parameters governing their formation and characteristics

Dul, M., Paluch, Krzysztof J., Kelly, H., Healy, A.M., Sasse, A., Tajber, L. 2 December 2015 (has links)
Yes / The aim of this work was to investigate the feasibility of cross-linker free polyelectrolyte complex formation at the nanoscale between carrageenan (CAR) and protamine (PROT). The properties of CAR/PROT nanoparticles (NPs) were dependent on the carrageenan type: kappa (KC), iota (IC) and lambda (LC), concentration of components, addition of divalent cations, weight mixing ratio (WMR) of constituents and mode of component addition. In the case of 0.1% w/v solutions, IC-based NPs had the smallest particle sizes (100-150nm) and low polydispersity indices (0.1-0.4). A decrease in the solution concentration from 0.1% to 0.05% w/v enabled the formation of KC/PROT NPs. All carrageenans exhibited the ability to form NPs with surface charge ranging from -190 to 40mV. The inclusion of divalent cations caused an increase in the particle size and zeta potential. Infrared analysis confirmed the presence of a complex between CAR and PROT and showed that IC chains undergo structural changes when forming NPs. Colloidal stability of NPs was related to the initial surface charge of particles and was time- and pH-dependent. IC was found to be the most suitable type of CAR when forming nanoplexes with PROT.
18

Chondroitin-based nanoplexes as peptide delivery systems-Investigations into the self-assembly process, solid-state and extended release characteristics

Umerska, A., Paluch, Krzysztof J., Santos-Martinez, M.J., Medina, C., Corrigan, O.I., Tajber, L. 20 April 2015 (has links)
Yes / A new type of self-assembled polyelectrolyte complex nanocarrier composed of chondroitin (CHON) and protamine (PROT) was designed and the ability of the carriers to bind salmon calcitonin (sCT) was examined. The response of sCT-loaded CHON/PROT NPs to a change in the properties of the liquid medium, e.g. its pH, composition or ionic strength was studied and in vitro peptide release was assessed. The biocompatibility of the NPs was evaluated in Caco-2 cells. CHON/PROT NPs were successfully obtained with properties that were dependent on the concentration of the polyelectrolytes and their mixing ratio. X-ray diffraction determined the amorphous nature of the negatively charged NPs, while those with the positive surface potential were semi-crystalline. sCT was efficiently associated with the nanocarriers (98-100%) and a notably high drug loading (13-38%) was achieved. The particles had negative zeta potential values and were homogenously dispersed with sizes between 60 and 250 nm. CHON/PROT NPs released less than 10% of the total loaded peptide in the first hour of the in vitro release studies. The enthalpy of the decomposition exotherm correlated with the amount of sCT remaining in NPs after the release experiments. The composition of medium and its ionic strength was found to have a considerable influence on the release of sCT from CHON/PROT NPs. Complexation to CHON markedly reduced the toxic effects exerted by PROT and the NPs were compatible and well tolerated by Caco-2 cells.

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