Intimal hyperplasia is associated with graft failure and vascular sutures in the first year after surgery and in postangioplasty restenosis. Allium sativum (common garlic) lowers cholesterol and has antioxidant effects; it also has antiplatelet and antitumor properties and, therefore, has great potential to reduce or inhibit intimal hyperplasia of the arteries. Attempts have been made to inhibit intimal hyperplasia of the arteries with cilostazol and other drugs. Therefore, it is important to address the following research question: what is the difference between the mean of post-angioplasty myointimal thickening in the iliac artery of rabbits treated with A. sativum and that treated with cilostazol? Our objective is to determine the mean difference of post-angioplasty myointimal hyperplasia in the external iliac artery of rabbits with induced atherosclerosis, and compare the outcome between treatment with A. sativum and treatment with cilostazol. This is a randomized preclinical trial study conducted in experimental animals. We used female New Zealand rabbits (Oryctolagus cuniculus), submitted to an atherosclerotic diet and angioplasty of the external iliac artery. The animals were divided into the following groups (n = 10 each) according to treatment: group A, A. sativum, 800 μg⋅kg-1⋅day-1, orally; group C, cilostazol, 50 mg/day, orally; group S, 10 mL of 0.9% physiological saline solution, orally. Our primary variable is the difference of the mean myointimal hyperplasia. The secondary variable is the mean plate thickness of the arterial wall. Complementary data include frequency of limb ischemia, limb loss frequency, frequency of hematoma or bruising, frequency of infection, frequency of bleeding, frequency of animal death, and mean of lipid levels. The sample size was arbitrated in 30 rabbits. Statistical analysis was performed by using ANOVA and Tukey tests, as well as the χ2 test. We calculated the 95% confidence interval (CI) for each point estimate, and the P value was set as < 0.05. Group S had a mean hyperplasia rate of 35.74% (95% CI, 31.76–39.71%); group C, 16.21% (95% CI, 13.36–19.05%); and group A, 21.12% (95% CI, 17.26–25.01%); P < 0.0001. In conclution the Allium sativum quite as effective in inhibiting myointimal hyperplasia compared with those treated with cilostazol. / A hiperplasia intimal está relacionada à falha de enxertos e suturas vasculares no primeiro ano pós-cirurgia e nas reestenoses pós-angioplastia. O Allium sativum (alho comum) reduz o colesterol e tem efeito antioxidante, antiplaquetário e antitumoral; logo havia grande possibilidade de reduzir ou inibir a hiperplasia da íntima das artérias, a qual sua inibição vem sendo tentada com o Cilostazol e outros tratamentos. Sendo assim é relevante responder a pergunta de pesquisa: qual a diferença de média de hiperplasia miointimal pós-angioplastia na artéria ilíaca de coelhos tratados com Allium sativum comparada aos tratados com Cilostazol? O objetivo é determinar a diferença de média de hiperplasia miointimal pós-angioplastia na artéria ilíaca externa de coelhos com aterosclerose induzida e tratados com Allium sativum comparada aos tratados com Cilostazol. O estudo foi um ensaio pré-clínico aleatório em animais de experimentação por 35 dias. Os animais foram coelhos fêmeas (Oryctolagus cuniculus), da linhagem Nova Zelandia, submetidos à dieta ateroslcerótica e à angioplastia da artéria ilíaca externa direita. Os animais foram divididos em: Grupo A (n=10) coelhos tratados com a Allium sativum (800 μg/kg/dia), em doses diárias, por via oral. Grupo C (n=10): coelhos tratados com Cilostazol em doses diárias de 50 mg/dia, por via oral. Grupo S (n= 10) coelhos tratados com 10 mL de soro fisiológico 0,9%, por via oral, que foi nosso controle negativo. A variável primária foi a diferença de frequência da média de hiperplasia miointimal. Variáveis secundárias: a média de espessura da placa na parede arterial. Dados complementares: a frequência isquemia do membro, a frequência de perda do membro, a frequência de hematoma ou equimose, a frequência de infecção, a frequência de sangramento, a frequência de morte do animal e a média dos níveis lipídicos. O tamanho da amostra foi arbitrado em 30 coelhos. A análise estatística foi realizada com o teste ANOVA, Qui-quadrado e Tukey. Foi calculado o intervalo de confiança de 95% para cada ponto estimado. Os resultados foram: grupo S teve um índice médio de hiperplasia de 35,74% IC de 95% (31,76% a 39,71%); grupo C teve um índice médio de hiperplasia de 16,21% IC de 95% (13,36% a 19,05%); grupo A teve um índice médio de hiperplasia de 21,12% IC de 95% (17,26% a 25,01%); com P < 0,0001. Sendo assim, o Allium sativum tem a mesma eficácia na inibição da hiperplasia miointimal comparada aos tratados com Cilostazol

Orientador: João Roberto Gonçalves / Resumo: O objetivo deste estudo foi analisar as alterações morfológicas dos côndilos de indivíduos Classe III (média 17,1 anos) com hiperplasia condilar submetidos a osteotomia sagital bilateral da mandíbula concomitante à condilectomia alta no lado afetado. Foram utilizadas tomografias computadorizadas de feixe cônico (TCFC) de 22 côndilos, em três tempos distintos: T1 (pré-operatório), T2 (pós-operatório imediato) e T3 (média de 11 meses de acompanhamento). A análise qualitativa das alterações morfológicas das imagens das TCFC foi realizada por observação de semi-transparências derivadas de superposições tridimensionais por uma pesquisadora calibrada. A maioria dos côndilos receberam ostectomia do pólo superior (n=15), enquanto que em apenas 7, a ostectomia foi súpero-lateral. Foi observado que a maioria dos côndilos que apresentaram deslocamento para medial em T2-T1, apresentaram crescimento nos pólos condilares em T3-T2, nas seguintes frequências: pólo anterior (42,8%, n=3); pólo medial (42,9%, n=3); pólo lateral (18,8%, n=3); pólo posterior (47,1%, n=8). Com relação a frequência de reabsorção, nos pólos anterior e lateral foram observados os seguintes valores: 14,3% (n=1) e 18,8% (n=3), respectivamente (p>0.05). Para os côndilos que apresentaram deslocamento lateral em T2-T1, o crescimento nem sempre esteve entre as alterações mais comuns em T3-T2; entretanto, ocorreu na seguinte frequência: pólo anterior (7,7%, n=1); pólo medial (18,2%, n=2); pólo lateral (100%, n=1); pólo post... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to analyze the morphological alterations of the condyles in Class III individuals (mean age: 17.1 years) with condylar hyperplasia submitted to maxillomandibular osteotomies concomitant with high condylectomy on the affected side. CT scans of 22 condyles were used at three different times: T1 (preoperative), T2 (immediate postoperative) and T3 (mean of 11 months follow-up). The qualitative analysis of the morphological alterations of the CBCT images was performed by observing semi-transparencies derived from three-dimensional overlays by a calibrated researcher. Upper pole ostectomies were performed in most condyles were cut at the upper pole (n=15), while supero-lateral ostectomies were made on 7 condyles. It was observed that most of the condyles that underwent inward displacement in T2-T1, further underwent growth in the condylar poles in T3-T2, in the following frequencies: anterior pole (42.8%, n=3); medial pole (42.9%, n=3); lateral pole (18.8%, n=3); posterior pole (47.1%, n=8). Regarding the frequency of resorption, the following values were observed in the anterior and lateral poles: 14.3% (n=1) and 18.8% (n=3), respectively (p>0.05). The type of condilectomy did not interfere with changes in T3-T2, as well as changes in the right and left condyles (p>0.05). It was possible to conclude that the most common postoperative condylar alteration was the antero-medial displacement when the result was analyzed immediately after surgery (T2-T1), and ... (Complete abstract click electronic access below) / Doutor

It was shown almost 50 years ago that hypothermic incubation of chicken embryos results in a reduction in the size of embryos and an increase in the heart weight, presumably by hypertrophy (increase in cell volume). The chicken embryos were incubated in normothermia (37.5 ř C) and hypothermia (33.5 ř C) from the eleventh embryonic day. On the 17th day, the embryos were weighed and then their hearts were weighed. In agreement with the previous results, hypothermic embryos were 29% smaller and their hearts 18% heavier. The heart-to-body weight ratio was 67% higher in the hypothermic group. The measured cell size was very similar in the target areas and it was also between the two groups. The left ventricle width was twofold that the right one and the difference was not significantly higher in the hypothermia model. Purkinje fibers, the terminal part of the conduction system, were smaller than the working cardiomyocytes. Purkinje fibers were slightly enlarged after hypothermic incubation. The proliferation rate was measured by immunohistochemical labeling of anti-phospho histone H3. The experimental group showed much higher proliferation rate; it reached statistical significance in the right ventricle. Thus, hypothermic incubation resulted in increased growth of embryonic heart based on hyperplasia...

No description available.

No description available.

No description available.

No description available.

H2S is a biologically relevant signaling gas that is endogenously produced throughout the body. The (patho)physiological roles of H2S have led researchers to develop various compounds that decompose to release H2S (H2S donors) for exogenous H2S administration. However, many small molecule H2S donors suffer from poor solubility, low stability, and lack of control over H2S release rates. As a result, there has been an increasing interest in utilizing supramolecular materials for exogenous H2S delivery. With growing potential applications of supramolecular H2S-releasing materials, it is important to explore their properties, e.g., solubility and stability under physiological conditions. We investigated the hydrolytic stability over a range of pH conditions of a series of peptides containing H2S-releasing S-aroylthiooximes (SATOs). The SATO-peptides showed structure–reactivity relationships with SATO ring substituents playing a crucial role in hydrolysis rates. Electron-donating substituents accelerate the rate of hydrolysis while electron-withdrawing substituents slows it down. We also explored their hydrolysis mechanisms at different pH values. SATO-peptides were then used to form hydrogels at 1 wt.% triggered by Ca2+. Hydrogels can be applied directly at a site of interest, potentially improving the efficacy of H2S compared with small molecule donors that diffuse away. We developed a H2S-releasing hydrogel capable of slowly releasing H2S locally to test its efficacy on intimal hyperplasia. The hydrogel delivered H2S over the period of several hours and inhibited the proliferation of human vascular smooth muscle cells (VSMCs) significantly better than fast-releasing NaSH salts. This study shows a promising application of supramolecular H2S-releasing materials over widely used sulfide salts. The macroscopic properties of peptide hydrogels could be further modulated to achieve additional control over the H2S release properties. We synthesized a series of peptide hydrogels incorporating different linker segments to study their effects on hydrogelation properties. Most peptides formed hydrogels but with significantly different rheological behavior. We found that peptides with flexible linkers such as ethyl, substituted O-methylene, and others, formed stronger hydrogels compared to those with more rigid linkers. Interestingly, we found that stiffer hydrogels released H2S over longer periods than softer ones by retarding the diffusion of a thiol trigger, likely due to bulk degradation of the soft gels but surface erosion of the stiff gels as they release H2S. / Doctor of Philosophy / H2S has long been known as a foul smelling gas until it was discovered that it is endogenously produced throughout the body and plays many (patho)physiological roles. Therapeutic benefits of H2S have led researchers to develop various compounds that release H2S (H2S donors) for exogenous H2S administration. However, many small molecule H2S donors suffer from poor solubility, low stability, and unregulated H2S release. As a result, there has been an increasing interest in utilizing materials for exogenous H2S delivery. With growing potential applications of H2S-releasing materials, it is important to explore their properties, e.g., solubility and stability under physiological conditions. We investigated the stability of a series of peptides containing H2S-releasing S-aroylthiooximes (SATOs) over a range of pH conditions. The stability of SATO-peptides was dependent on chemical makeup of the SATO part of the peptides. We also explored their hydrolysis mechanisms at different pH values. SATO-peptides were then used to form hydrogels triggered by Ca2+. Hydrogels can be applied directly at a site of interest, potentially improving the efficacy of H2S compared with small molecule donors that diffuse away. We developed a H2S-releasing hydrogel capable of slowly releasing H2S locally to test its efficacy on intimal hyperplasia. The hydrogel delivered H2S over the period of several hours and inhibited the proliferation of human vascular smooth muscle cells (VSMCs) significantly better than fast-releasing NaSH salts. This study shows a promising application of supramolecular H2S-releasing materials over widely used sulfide salts. The macroscopic properties of peptide hydrogels could be further modulated to achieve additional control over the H2S release properties. We synthesized a series of peptide hydrogels incorporating different linker segments to study their effects on hydrogelation properties. Most peptides formed weak to strong hydrogels with calcium chloride.We found that peptides with flexible linkers formed stronger hydrogels compared to those with more rigid linkers. Interestingly, we found that stiffer hydrogels released H2S over longer periods than softer ones.

<p>Disease-specific compounds (biomarkers) are analyzed in clinical laboratories to assist with diagnosing diseases. This thesis describes development and validation of liquid chromatography tandem mass spectrometry (LC-MS/MS) based tests for diagnosing a diverse group of endocrine and metabolic diseases. The analytical methods used on-line and off-line sample extraction and analytical derivatization as means of enhancing the analytical sensitivity, specificity and clinical utility. All developed methods were extensively validated and reference intervals for the biomarker concentrations were established in blood samples of healthy adults and children. Advantages of the LC-MS/MS as an analytical technique include possibility of simultaneous measurement of multiple analytes and ability of confirming their identity. In this thesis we proposed and evaluated approaches for the assessment of the specificity of analysis in the methods that use tandem mass spectrometry detection. To enhance throughput of the LC-MS/MS tests for the biomarkers that have endogenous or exogenous isomers an approach was developed for quantitation of isomers from unresolved chromatographic peaks. Using methods developed in this thesis we performed a study of the steroidogenesis in ovarian follicles of healthy women and women with polycystic ovary syndrome (PCOS). Obtained data on the steroid concentrations and associations between the steroid metabolites in the pathway would be helpful for better understanding of the ovarian pathophysiology. Potential biomarkers of PCOS were identified in the thesis; further studies will be necessary to confirm their clinical utility.</p>

Cellular and molecular mechanisms of postembryonic muscle fibre recruitment were investigated in zebrafish (Danio rerio L.), a standard animal model for developmental and genetic studies. Distinct cellular mechanisms of postembryonic muscle fibre recruitment in fast and slow myotomal muscles were found. In slow muscle, three overlapping waves of stratified hyperplasia (SH) from distinct germinal zones sequentially contributed to a slow and steady increase in fibre number (FN) through the life span. In fast muscle, SH only contributed to an initial increase of FN in early larvae. Strikingly, mosaic hyperplasia (MH) appeared in late larvae and early juveniles and remained active until early adult stages, accounting for >70% of the final fibre number (FFN). The molecular regulation of postembryonic muscle fibre recruitment was then studied by characterising myospryn and cee, two strong candidate genes previously identified from a large scale screen for genes differentially expressed during the transition from hyperplastic to hypertrophic muscle phenotypes. Zebrafish myospryn contained very similar functional domains to its mammalian orthologues, which function to bind to other proteins known to regulate muscle dystrophy. Zebrafish myospryn also shared a highly conserved syntenic genomic neighbourhood with other vertebrate orthologues. As in mammals, zebrafish myospryn were specifically expressed in striated muscles. Zebrafish cee was a single-copy gene, highly conserved among metazoans, ubiquitously expressed across tissues, and did not form part of any wider gene family. Its protein encompassed a single conserved domain (DUF410) of unknown function although knock-down of cee in C. elegans and yeast have suggested a role in regulating growth patterns. Both myospyrn and cee transcripts were up-regulated concomitant with the cessation of postembryonic muscle fibre recruitment in zebrafish, indicating a potential role in regulating muscle growth. Furthermore, a genome-wide screen of genes involved in the regulation of postembryonic muscle fibre recruitment was performed using microarray. 85 genes were found to be consistently and differentially expressed between growth stages where muscle hyperplasia was active or inactive, including genes associated with muscle contraction, metabolism, and immunity. Further bioinformatic annotation indicated these genes comprised a complex transcriptional network with molecular functions, including catalytic activity and protein binding as well as pathways associated with metabolism, tight junctions, and human diseases. Finally, developmental plasticity of postembryonic muscle fibre recruitment to embryonic temperature was characterised. It involved transient effects including the relative timing and contribution of SH and MH, plus the rate and duration of fibre production, as well as a persistent alteration to FFN. Further investigation of FFN of fish over a broader range of embryonic temperature treatments (22, 26, 28, 31, 35°C) indicated that 26°C produced the highest FFN that was approximately 17% greater than at other temperatures. This finding implies the existence of an optimal embryonic temperature range for maximising FFN across a reaction norm. Additionally, a small but significant effect of parental temperature on FFN (up to 6% greater at 24 and 26°C than at 31°C) was evident, suggesting some parental mechanisms can affect muscle fibre recruitment patterns of progeny. This work provides a comprehensive investigation of mechanisms underlying postembryonic muscle fibre recruitment and demonstrates the power of zebrafish as an ideal teleost model for addressing mechanistic and practical aspects of postembryonic muscle recruitment, especially the presence of all major phases of muscle fibre production in larger commercially important teleost species.