Thesis (doctoral)--Lund University, 1997. / Added t.p. with thesis statement inserted.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Vito, Raymond; Committee Member: Gleason, Rudolph; Committee Member: Rachev, Alexander. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (doctoral)--Rijksuniversiteit te Groningen, 1980. / Summary and vita in Dutch. Highlights sheet in Dutch inserted. Vita. Includes bibliographical references (p. 125-140).

Thesis (Ph. D.)--University of Missouri--Columbia, 2005. / "July 2005" Typescript. Vita. Includes bibliographical references (l. 197-212). Also issued on the Internet.

Thesis (Ph. D.)--University of Missouri--Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 189-204). Also available on the Internet.

BACKGROUND: Arterial stiffness (AS), or loss of elastic compliance of large arteries, is an independent risk factor for cardiovascular events1. A recent study demonstrated that single nucleotide polymorphisms (SNPs) in a genetic locus downstream of the gene Bcl11b are associated with AS2. However, how this genetic locus and Bcl11b regulate AS is unknown. OBJECTIVES: To determine the molecular mechanisms by which Bcl11b effects the aortic wall and AS. METHODS: Vascular smooth muscle (VSM) cells were isolated from aortas of wildtype (WT) mice and mice with VSM-specific Bcl11b deletion (BKO). mRNA levels of Bcl11b, vascular contractile markers (myosin heavy chain 11 (MYH11), smooth muscle -actin (ACTA2), and myocardin (MYOCD)) and a cell proliferation marker (Ki67) were measured in WT and BKO VSM cells isolated from murine aortas. VSM cell contractility in response to angiotensin II (angII), a contractile stimulus, was measured in WT and BKO VSM cells using an optimized collagen gel contractility assay. RESULTS: BKO VSM cells had decreased expression of contractile markers compared to WT cells, which resulted in impaired collagen gel contraction in response to angII. CONCLUSIONS: Bc111b is expressed in aortic smooth muscle cells and it regulates the expression of VSM contractile proteins. Our data strongly supports the hypothesis that Bcl11b regulates AS by regulating the contractile function of VSM cells in the aortic wall. / 2019-07-11T00:00:00Z

Background: An ex vivo experimental strategy replicating in vivo intestinal development would provide an accessible setting to study normal and dysmorphic biology, and would be a test bed for tissue engineering. Previous studies implicated transforming growth factor β1 (TGFβ1) in postnatal gut maturation and regeneration following injury, but its potential role in intestinal development is poorly understood. I firstly hypothesised that embryonic small intestine is able to heal after physical injury. To test this idea, I aimed to create an organ culture model using explants of embryonic jejunum. I secondly hypothesised that TGFβ1 affects embryonic small intestine growth and differentiation. Accordingly, I aimed to use the same organ culture model to determine potential effects of exogenous TGFβ1.Methods. Segments of mouse embryonic jejunum were isolated by dissection and placed on semipermeable platforms. They were fed with defined, serum free, media, in some cases supplemented with TGFβ1. Growth, differentiation and healing of explants were characterized and quantified using a battery of techniques that included whole mount imaging, histology, immunostaining and RNA arrays. TGFβ1 was measured in amniotic fluid by enzyme-linked immunosorbent assay. Groups were compared by statistical tests. Results: After three days of culture, jejunal rudiments differentiated from simple tubes into a more complex structures containing smooth muscle surrounding newly formed villi. Pairs of rudiments, linked by a thread, fused and formed a continuous single lumen, as assessed by trajectories of fluorescent dextrans injected into their distal ends. Functional continuity was confirmed by spontaneous waves of peristalsis crossing the point of fusion. In vivo, TGFβ receptors I and II were detected in embryonic longitudinal smooth muscle cells and, in organ culture, exogenous TGFβ1 induced differentiation of longitudinal smooth muscle. Microarray profiling showed that TGFβ1 increased smooth muscle associated transcripts in a dose-dependent manner. TGFβ1 protein was detected in amniotic fluid at a time when the embryonic small intestine was physiologically herniated. Conclusion: Embryonic jejunal segments can fuse to form a single functional organ when aided by a mechanical manipulation. By analogy with the requirement for exogenous TGFβ1 for smooth muscle differentiation in culture, the TGFβ1 protein that I demonstrated to be present in the amniotic fluid may enhance intestinal development when it is physiologically herniated in early gestation. Future studies of embryonic intestinal cultures should add TGFβ1 in the defined media to produce a more faithful model of in vivo muscle differentiation. In future, this model could be used to test whether other growth factors enhance intestinal growth, and so pave the way to novel biological treatments for short bowel syndrome, a devastating disease with a high mortality.

Orientador: Paulo Cesar Rodrigues Palma / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-04T10:03:35Z (GMT). No. of bitstreams: 1 Dambros_Miriam_D.pdf: 5436149 bytes, checksum: adcf62040b0e93aa24e7479ee60c4ebb (MD5) Previous issue date: 2005 / Resumo: Os agentes antimuscarínicos permanecem como drogas de primeira linha para o tratamento da Síndrome da Bexiga Hiperativa (SBH), a despeito das dúvidas ainda existentes sobre a significância clínica e sua eficácia. Poucos fármacos que atuam por meio de mecanismos distintos dos antimuscarínicos, têm demonstrado eficácia no tratamento da SBH. Ravonóides são um grupo de compostos polifenólicos que têm recebido especial atenção dentro da pesquisa básica e clínica devido ao seu amplo espectro de atividade farmacológica. Recentemente, um estudo in vitro demonstrou que o fIavonóide galangina exerce uma atividade inibitória sobre a contratilidade da bexiga de ratos. Esta tese foi desenvolvida a fim de examinar os efeitos da galangina sobre a resposta contrátil da bexiga de suínos e testar a hipótese de um efeito sobre a mobilização do cálcio. Além disso, investigou-se a eficácia da galangina em promover uma ação protetora sobre o dano da musculatura lisa da bexiga causada por um período de estimulação elétrica repetitiva, o qual é empregado como um modelo, in vitro, de hiperrefIexia. Em um grupo de experimentos, fragmentos do detrusor de suínos foram submetidos a um período de 90 mÍn de estimulação elétrica de repetição. Galangina, em diferentes concentrações, foi adicionada ao banho do órgão a fim de determinar seu possível efeito protetor durante a estimulação elétrica. Em outro grupo de experimentos, a resposta contrátil ao carbacol, cafeína, potássio e eletroestímulo foi determinada antes e após a adição de galangina (3xl0-sM) ao meio. Os efeitos do fIavonóide foram também avaliados após a administração de diferentes antagonistas no banho de órgão. Galangina (1O-7M) evitou o decréscimo da resposta contrátil do músculo liso causada por um período de estimulação elétrica de repetição. vesical Galangina inibiu a amplitude da contração detrusora induzi da pelo eletro-estímulo, carbacol, cafeína e potássio (p<0.05). O efeito inibitório do fIavonóide foi deixado inalterado após a introdução de diferentes antagonistas: propranolol, fentolamina e capsazepina, no banho de órgão (p>0,05). Entretanto, quando verapamil foi adicionado ao meio de estudo, a inibição da contração foi parcialmente abolida. Concluindo, os experimentos acima descritos demonstraram que a galangina, em concentração nanomolar, exerceu um efeito protetor sobre a musculatura detrusora. Entretanto, quando empregado em uma concentração micromolar, o flavonóide promoveu einibição da musculatura lisa vesical, o qual resultou de uma ação sobre a mobilização do cálcio extra e intracelular / Abstract: Antimuscarinjc agents remain first-line therapy for the overactive bladder syndrome (OAB), despite doubts about the clinjcal signifjcance of their effectiveness. Few drugs acting through other mechanisms have been found to be efficacious for treatment of GAB. Flavonoids are a group of polyphenolic compounds and have recently gained tremendous interest, due to their broad pharmacologjcal activity. Recently, the inhibitory effect of galangin, a member of the flavonol class of flavonoid, on rat bladder contractility has been investigated. This thesis was undertaken to further examine the actions of galangin on the contractile responses of bladder strips and to test the hypothesis that an effect on calcium mobilization in smooth muscle cells is involved. Furthermore, it was investigated the efficacy of galangin to counteract the detrusor damage caused by the smooth muscle of the urinary bladder being exposed to repetitive field stimulation (RFS), as a model of hyperreflexia. In one experiment, pig detrusor strips were mounted for tension recording in organ baths and were subjected to RFS for 90min. Galangin, at different concentrations, was added to the organ bath in order to determine its protective effect on RFS. In another experiment the contractile response to carbachol, potassium and electrical field stimulation - EFS were determined before and after the addition of galangin (3xlO-sM). Furthermore, the effect of galangin was also evaluated after the administration in the bath of a number of antagonists. Galangin (1O-7M)avoided the decrease in contractile smooth muscle response of strips to EFS during RFS. Galangin inhibited the maximal contractile response to EFS, carbachol, caffeine media and potassium (pO,O5).However, when verapamil was added to the medium, the inhibitory effects of galangin were partially blocked. In summary, the current experiments have shown that galangin, in subllmol concentrations, exerted a protective effect on bladder smooth muscle contractility. Furthermore, galangin, in !lIDO!concentrations inhibited pig bladder contractility, which probably resulted from an action on Ca2+mobilization from intracellu!ar stores as well as influx of calcium. At the present, there is no proof that our results are reproducible in functional or dysfunctional human bladders. Further study is needed to investigate the potential of ga!anginto be used to inhibited overactive bladder syndrome in vivo / Doutorado / Cirurgia / Doutor em Cirurgia

No description available.

Calcium-activated chloride channels (CaCCs) are ubiquitously expressed in a plethora of cell types and, consequently, are involved in numerous cellular processes as diverse as epithelial secretion, regulation of cardiac excitability and smooth muscle contraction. Current pharmacology of CaCCs is limited to compounds with low potency and poor selectivity. The lack of knowledge surrounding the molecular identity of the CaCC has greatly hindered the development of more specific drugs and has impaired our understanding of the channel physiology and biophysics. The recent discovery that the TMEM16A gene codes for CaCCs has offered hope for new developments in these areas. CaCCs have been suggested as possible targets to treat a variety of conditions including asthma as well as pulmonary and systemic hypertension. Due to the ubiquitous expression of CaCCs and the ability of the channel to interact with a number of pharmacological compounds with diverse chemical structures however, it was hypothesised that TMEM16A could be a possible source for off-target drug effects and may represent a concern for safety pharmacology. The principal aim of this thesis was to assess the functional significance of TMEM16A in the cardiovascular system, as this is one of the major systems of concern for safety pharmacology and accounts for the largest number of post-market drug withdrawals. The main findings of this study can be summarised as follows: 1) RT-PCR analysis revealed a ubiquitous expression of TMEM16A in tissues of the rat and human cardiovascular systems, including systemic and pulmonary arteries as well as cardiac tissue. Analysis also revealed the presence of multiple TMEM16A splice variants in all rat tissues examined, in addition to a number of other TMEM16x family members. 2) Myography experiments using the “classical” CaCC blocker niflumic acid and newly identified TMEM16A blockers confirmed a functional role for TMEM16A in phenylephrine-induced vascular smooth muscle contraction. 3) The suitability of currently available Cl- channel blockers for use as pharmacological tools for TMEM16A research was assessed using conventional whole-cell patch clamp and high-throughput electrophysiology techniques to respectively compare their potencies and selectivity over other cardiovascular ion channels. Of the compounds tested, DIDS and T16Ainh-A01 appeared the most suitable blockers; however all compounds had a degree of non-selectivity, raising concerns for their use in functional studies. In conclusion, these findings provide evidence for the ubiquitous expression and functional significance of TMEM16A within the cardiovascular system and support the hypothesis that TMEM16A is a concern for safety pharmacology and should be included into future pre-clinical safety assays. The inadequacy of current inhibitors however highlights the urgency for the development of novel potent and selective channel modulators for future TMEM16A research.