Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 4 uppsatser.

Zugl.: Stuttgart, Univ., Diss., 2006.

Resumo:Em humanos, a imunossupressão que ocorre em pacientes urêmicos está associada com a disfunção dos neutrófilos causada pelas toxinas urêmicas. O p-cresol se acumula no sangue de pacientes com insuficiência renal crônica (IRC) promovendo a inibição do metabolismo oxidativo dos neutrófilos. O presente trabalho teve como objetivo mensurar as concentrações plasmáticas de p-cresol em cães hígidos e com IRC e testar a hipótese de que o p-cresol livre causa disfunção neutrofílica. Para tal, foi quantificada a concentração plasmática de p-cresol por cromatografia de fase líquida (HPLC) em cães hígidos e com IRC no estágio IV. Também foi avaliado in vitro o efeito específico do p-cresol sobre o metabolismo oxidativo e a taxa de apoptose de neutrófilos de cães hígidos, considerando-se a maior concentração plasmática desta toxina observada in vivo em cães com IRC. Neutrófilos isolados de 20 cães saudáveis foram incubadas em meio de RPMI puro ou enriquecido com p-cresol e com plasma de cães com IRC. O metabolismo oxidativo dos neutrófilos foi avaliado por citometria de fluxo capilar utilizando as sondas hidroetidina e 2′,7′- diacetato de diclorofluoresceína com ou sem estímulos de acetato miristato de forbol e n-formil-metionil-leucilfenilalanina. A apoptose e a viabilidade dos neutrófilos foi quantificada em citômetro de fluxo capilar utilizando sistema Anexina V-PE, com ou sem estímulo de camptotecina. Cães com IRC apresentaram in vivo o quadro de estresse oxidativo e aumento do p-cresol plasmático. A maior concentração do p-cresol causou disfunção neutrofílica in vitro. Conclui-se que p-cresol pode estar envolvido com quadro de estresse oxidativo in vivo e que sua alta concentração diminua a viabilidade e leve a uma redução da produção de espécies reativas de oxigênio / Abstract:In humans, the immunosuppression observed in uremic patients is associated with the neutrophil dysfunction caused by uremic toxins. P-cresol accumulates in the blood of patients with chronic renal failure (CRF) promoting the inhibition of neutrophil oxidative metabolism. This study aimed to measure the plasma concentrations of p-cresol in dogs with CRF and test the hypothesis that free p-cresol causes neutrophil dysfunction. To this end, plasma concentration of p-cresol was determined using high pressure liquid chromatography (HPLC) in dogs presenting stage IV of CRF. The in vitro specific effect of p-cresol on the oxidative metabolism and apoptosis rate of neutrophils from healthy dogs was also evaluated, considering the highest plasma concentration of this toxin observed on the in vivo measurement of dogs with CRF. Isolated neutrophils from 20 healthy dogs were incubated in RPMI medium alone, supplemented with p-cresol or plasma from dogs with CRF. Neutrophil oxidative metabolism was assessed by capillary flow cytometry using the probes hydroethidine and 2',7'- dichlorofluorescein diacetate with or without stimulus with phorbol myristate acetate and N-formyl-methionyl-leucylphenylalanine. Apoptosis and viability of neutrophils were quantified also in capillary flow cytometry using Annexin V-PE system with or without stimulus with camptothecin. Dogs with CRF presented oxidative stress and increased plasma levels of p-cresol, the higher concentration of p-cresol caused in vitro neutrophil dysfunction. It can be concluded that p-cresol may be involved with in vivo oxidative stress that its higher concentration decreases the viability and lead to a reduced production of reactive oxygen species / Orientador:Paulo Cesar Ciarlini / Banca:Wagner Luis Ferreira / Banca:Alvaro José dos Santos Neto / Mestre

Resumo:Recentemente, foi relatado que na insuficiência renal crônica (IRC) canina ocorre estresse oxidativo e que a disfunção dos neutrófilos está associada ao aumento da apoptose. Dentre as muitas toxinas urêmicas que se concentram na IRC, há evidências em humanos de que as guanidinas inibem o metabolismo oxidativo dos neutrófilos, afetando a sua função bactericida. Uma revisão sistemática foi realizada sobre a relação entre os compostos guanidínicos e os neutrófilos em cães. Verificou-se que a literatura, sobre este tema, é escassa e contraditória, de modo que, foi investigado no presente estudo a relação entre a concentração de guanidina plasmática, a produção de superóxido e a apoptose de neutrófilos de cães com IRC. Aditivamente, foi investigado "in vitro" o efeito isolado do composto ácido guanidinoacético (AGA) sobre a produção de superóxido e a apoptose de neutrófilos de cães sadios. Foi possível comprovar que o grande aumento da guanidina plasmática observado em cães com IRC não está associado à alteração do metabolismo oxidativo e apoptose dos neutrófilos. O AGA inibiu o metabolismo oxidativo de neutrófilos de cães sadios sem afetar a viabilidade dessas células / Abstract:It has been recently reported that in canine chronic renal failure (CRF) there occurs oxidative stress, and that neutrophil dysfunction is associated with the increase of apoptosis. Among the many uremic toxins found in higher concentrations due to CRF, there is evidence - in humans - that guanidines inhibit the oxidative metabolism of neutrophils, affecting their bactericidal function. In this study, a systematic review of the relationship between guanidine compounds and neutrophils in dogs was undertaken. It was found that the literature on this subject is scarce and conflicting, which prompted this investigation of the relationship between the plasmatic concentration of guanidine, the production of superoxide, and the apoptosis of neutrophils in dogs with CRF. Morever, the effect of the isolated compound guanidine acetic acid (GAA) on the production of superoxide and on neutrophil apoptosis in healthy dogs was investigated in vitro. It was possible to verify that the large increase of plasmatic guanidine observed in dogs with CRF is not associated with the altered oxidative metabolism and the apoptosis of the neutrophils. The GAA inhibited the oxidative metabolism of the neutrophils in healthy dogs without affecting the viability of these cells / Orientador:Paulo Cesar Ciarlini / Banca:Fabiano Antonio Cadioli / Banca:Aureo Evangelista Santana / Mestre

Made available in DSpace on 2015-10-06T13:02:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-03-21. Added 1 bitstream(s) on 2015-10-06T13:19:28Z : No. of bitstreams: 1 000848868.pdf: 401988 bytes, checksum: 08ca73724d8938b9b116d34fb50815a0 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / In humans, the immunosuppression observed in uremic patients is associated with the neutrophil dysfunction caused by uremic toxins. P-cresol accumulates in the blood of patients with chronic renal failure (CRF) promoting the inhibition of neutrophil oxidative metabolism. This study aimed to measure the plasma concentrations of p-cresol in dogs with CRF and test the hypothesis that free p-cresol causes neutrophil dysfunction. To this end, plasma concentration of p-cresol was determined using high pressure liquid chromatography (HPLC) in dogs presenting stage IV of CRF. The in vitro specific effect of p-cresol on the oxidative metabolism and apoptosis rate of neutrophils from healthy dogs was also evaluated, considering the highest plasma concentration of this toxin observed on the in vivo measurement of dogs with CRF. Isolated neutrophils from 20 healthy dogs were incubated in RPMI medium alone, supplemented with p-cresol or plasma from dogs with CRF. Neutrophil oxidative metabolism was assessed by capillary flow cytometry using the probes hydroethidine and 2',7'- dichlorofluorescein diacetate with or without stimulus with phorbol myristate acetate and N-formyl-methionyl-leucylphenylalanine. Apoptosis and viability of neutrophils were quantified also in capillary flow cytometry using Annexin V-PE system with or without stimulus with camptothecin. Dogs with CRF presented oxidative stress and increased plasma levels of p-cresol, the higher concentration of p-cresol caused in vitro neutrophil dysfunction. It can be concluded that p-cresol may be involved with in vivo oxidative stress that its higher concentration decreases the viability and lead to a reduced production of reactive oxygen species

Made available in DSpace on 2015-10-06T13:03:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-17. Added 1 bitstream(s) on 2015-10-06T13:18:35Z : No. of bitstreams: 1 000848874.pdf: 475629 bytes, checksum: 8f3083521bd5dbb20833e54b2e295e0b (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / It has been recently reported that in canine chronic renal failure (CRF) there occurs oxidative stress, and that neutrophil dysfunction is associated with the increase of apoptosis. Among the many uremic toxins found in higher concentrations due to CRF, there is evidence - in humans - that guanidines inhibit the oxidative metabolism of neutrophils, affecting their bactericidal function. In this study, a systematic review of the relationship between guanidine compounds and neutrophils in dogs was undertaken. It was found that the literature on this subject is scarce and conflicting, which prompted this investigation of the relationship between the plasmatic concentration of guanidine, the production of superoxide, and the apoptosis of neutrophils in dogs with CRF. Morever, the effect of the isolated compound guanidine acetic acid (GAA) on the production of superoxide and on neutrophil apoptosis in healthy dogs was investigated in vitro. It was possible to verify that the large increase of plasmatic guanidine observed in dogs with CRF is not associated with the altered oxidative metabolism and the apoptosis of the neutrophils. The GAA inhibited the oxidative metabolism of the neutrophils in healthy dogs without affecting the viability of these cells

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23004号 / 理博第4681号 / 新制||理||1671(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 WENDELL Roger, 教授 中家 剛, 准教授 久徳 浩太郎 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Theta-burst stimulation (TBS) is a form of repetitive transcranial magnetic stimulation (TMS) developed to induce neuroplasticity. TBS usually consists of 50 Hz bursts at 5 Hz intervals. When applied intermittently, it can lead to facilitation of motor evoked potentials (MEPs), although these effects can be variable between individuals. Here, we aimed to determine whether a version of intermittent TBS (iTBS) consisting of 30 Hz bursts at 6 Hz intervals would produce less variable modulation. Nineteen healthy adults underwent single-pulse TMS to assess corticomotor excitability at baseline as reflected in MEP amplitude. 30 Hz iTBS was then administered and MEP amplitude was reassessed at 5-, 20- and 45-mins after the iTBS protocol. Compared to baseline, MEPs were significantly facilitated up to 45-min post-iTBS and most participants exhibited the expected facilitation. These observations suggest that 30 Hz/6 Hz iTBS may provide a sound alternative to induce consistent neuromodulatory effects over the commonly used 50 Hz/5 Hz protocol.

Stroke is a medical condition in which poor blood flow to the brain results in cell death. The current treatment options are limited and only very few patients can benefit from these treatments. Stroke causes brain swelling and often a decompressive craniectomy is performed for some of the patients to release intracranial pressure to prevent further damage. As a result, a duraplasty is implanted to replace the surgically-damaged dura mater to protect the brain. In view of that, the purpose of this project was to develop double-walled microspheres (DWMS) which can be used as a drug delivery system when incorporated into duraplasty to promote endogenous stem cell therapy to treat stroke. The DWMS were composed of poly (l-lactic acid) (PLLA) and poly (lactic-co-glycolic acid) (PLGA) using a solvent evaporation method. Bovine serum albumin (BSA), as a model protein, was entrapped within these DWMS with different core-shell thicknesses and compositions to investigate the distribution of protein, encapsulation efficiency, and in vitro release. The fabrication process parameters of DWMS were also optimized to attain higher yields, and the phase separation and surface morphology were examined by differential scanning calorimetry and scanning electron microscopy.

This Ph.D. work is dedicated to advancements in burst-mode laser technology and their applications in MHz-rate high-speed gas-phase environments. A comprehensive computational model for simulating experimental burst-mode systems is discussed. Direct comparison of the modeled results to the output of a constructed nanosecond (ns) burst-mode laser shows agreement within a factor of 2 for output energy, the temporal domain skews positively in an appropriate manner, and the spectral domain correctly remains unchanged. The modeled output of a femtosecond (fs) burst-mode laser displays near perfect agreement with its hardware, generating only a 1.7% deviation for output energy, an 11% deviation in spectral bandwidth, and a temporal profile that correctly remains unchanged. The experimental ns to fs burst-mode lasers systems used to compare with the aforementioned model are described in detail and demonstrated for use in measurements of temperature, species, and velocity at high repetition rates. In the ns regime, a compact-footprint (0.18 m2 ) flashlamp-pumped, burst-mode Nd:YAGbased master-oscillator power-amplifier (MOPA) laser is developed with a fundamental 1064 nm output of over 14 J per burst. This portable laser system uses a directly modulated diode laser seed source to generate 10 ms duration arbitrary sequences of 500 kHz doublet or MHz singlet pulses for flow-field velocity or species measurements, respectively. In the fs regime, a flashlamp-pumped burst-mode laser system with high peak power and a broad spectral bandwidth of >10 nm is constructed without the use of nonlinear compression techniques. A mode-locked, 1064.6 nm fundamental-wavelength broadband master oscillator, a fiber amplifier/pulse stretcher, and four Nd:glass power amplifiers are used to generate a sequence of high-repetition-rate, transform-limited 234 fs pulses over a 1 ms burst duration at a 0.1 Hz burst repetition rate. The generated peak powers are 1.24 GW at 100 kHz and 500 MW at 1 MHz with M2∼1.5. An adaptation of the fs burst-mode laser is used for femtosecond laser electronic excitation tagging (FLEET) of nitrogen for tracking the velocity field in high-speed flows at kilohertz– megahertz (kHz–MHz) repetition rates without the use of added tracers. The fs burst-mode laser is used to produce 500 pulses per burst with pulses having a temporal separation as short as 1 µs, an energy of 120 µJ, and a duration of 274 fs. This enables 2 orders of magnitude higher measurement bandwidth over conventional kHz-rate FLEET velocimetry. 15 The fs burst-mode system was further improved to include a picosecond (ps) leg for hybrid fs/ps rotational coherent anti-Stokes Raman scattering (RCARS) at MHz rates. Using a common fs oscillator, the system simultaneously generates time synchronized 1061 nm, 274 fs and 1064 nm, 15.5 ps pulses with peak powers of 350 MW and 2.5 MW, respectively. The system is demonstrated for two-beam fs/ps RCARS in N2 at 1 MHz with a signal-to-noise ratio of 176 at room temperature. This repetition rate is an order of magnitude higher than previous CARS using burst-mode ps laser systems and two to three orders of magnitude faster than previous continuously pulsed fs or fs/ps laser systems. As a continuation of the above advances in fs regime, a regenerative fs burst-mode laser is discussed in detail with motivations, design layouts, and cavity physics laid out. Preliminary construction of the system with a ns seed source is underway to assess the detailed system design and evaluate the potential for optical damage due to Kerr lensing or other nonlinear effects. This system and other potential follow-on research topics are discussed.