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Factors that affect horizontal gene transfer in enteric bacteriaPeterson, Gregory Jay January 1900 (has links)
Doctor of Philosophy / Department of Diagnostic Medicine/Pathobiology / Sanjeev Narayanan / Antimicrobial resistance (AMR) has arisen as one of the most important public health concerns in the last 60 years. AMR results from pathogenic strains of bacteria adapting to antimicrobial-containing environments through mutations or through horizontal gene transfer (HGT) of genetic material containing resistance genes. Conjugation machinery offers an efficient method for acquisition of AMR and virulence genes, which may be responsible for propelling the evolution of pathogenic bacteria. This dissertation explores the factors, specifically catecholamines and antimicrobials that influence the conjugation frequencies of enteric bacteria including Salmonella, E. coli and Enterococcus. We found that the catecholamine norepinephrine (NE) at physiological concentrations enhanced conjugation efficiencies of a conjugative plasmid from a clinical strain of Salmonella Typhimurium to an E. coli recipient in vitro. Additional experiments determined the influence of the antimicrobial concentrations above, equal to and below the minimum inhibitory concentration (MIC) under in vitro conditions on conjugation efficiencies using an Enterococcus to Enterococcus mating pair in addition to the Salmonella to E. coli mating pair. Conjugation occurred in all concentrations, but efficiencies of transfer were consistently low in 0 MIC and 1 MIC, with increased activity both above and below 1 MIC. These data were fit to a previously described mathematical model and the rate constant E that relates the rate of gene transfer to drug concentration was determined. The data showed highly similar patterns of conjugation efficiencies when compared to the rate constant E. A final study we measured conjugation frequencies when donor Salmonella Typhimurium and the E. coli recipient were exposed to both variable concentrations of oxytetracycline and NE. Conjugation was increased pre- and post- MIC, but conjugation frequencies were not enhanced further by the combination of the oxytetracycline and the NE. This dissertation defines the role of outside factors in conjugative gene transfer, and may provide future insight into better control of AMR.
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Efeitos do estresse pré-natal sobre a atividade de linfócitos de uma prole de camundongos / Effects of prenatal stress on the lymphocytes mice litter activityKieling, Karin 09 April 2009 (has links)
Sabe-se que o feto é vulnerável a modificações do millieu materno, especificamente, a exposição a um estressor ativa sistemas neuroendócrinos (expoentes o eixo hipotálamo-hipófise-adrenais HPA e o sistema nervoso autônomo simpático SNAS). Quando no terço final da gestação, essas mudanças podem interferir com o desenvolvimento/ maturação neuroimune. Estudos prévios de nosso grupo demonstraram que, o estresse pré-natal diminuiu significativamente a imunidade inata e aumentou o turnover de noradrenalina hipotalâmica de camundongos, dados que somados a outros de literatura levaram aos objetivos deste trabalho: analisar os efeitos de um estresse pré-natal sobre parâmetros de linfócitos de camundongos. Os resultados obtidos mostraram que a aplicação de choques nas patas (0,2 mA, 10 choques/sessão), tanto no terço final gestacional quanto após desafio agudo pós-natal, contudo, não modificou significativamente os parâmetros linfocitários avaliados. Baseado nisto, levantamos hipóteses: 1- a existência de vias de redundância fisiológica capacitaria o organismo a manter sua homeostasia frente aos estressores empregados; 2- inaptidão do modelo de estresse empregado; 3- ausência de desafio imune prévio à análise de um sistema que é responsivo (adaptativo). A primeira hipótese confirmou-se quando desenvolvemos como estresse pós-natal o modelo do estresse do metrô de Nova Iorque; a segunda hipótese confirmou-se também verdadeira através de desafio em modelo experimental de a asma OVA-induzida; finalmente, a terceira hipótese foi confirmada por estudos de outros autores. / As a consequence of his fast development, the fetus is vulnerable to modifications from the hormonal maternal millieu. This is explained mainly by the permeability of the placentary barrier to several hormones and substances. Specifically, it is known that the maternal exposition to a stressor activates neuroendocrine systems (exponents, the hypothalamus-pituitary-adrenal axis HPA, and the sympathetic autonomic nervous system SANS), causing an exaggerated production of neuropeptides, which have the potential to change the motherly-fetus homeostasis. When this unbalance occurs in the final three months of pregnancy, it may impact fetal systems that are still being developed/matured, as the immune and nervous systems. According to previous studies, the prenatal-stress proposed in this work was able to produce a significant decrease on innate immunity as assessed by the evaluation of the activity of peritoneal macrophages; it was also, a significant increment in hypothalamic noradrenaline turnover. Such prenatal events, could be derived and/or reflect a lost in adaptative immunity homeostasis. The objective of this work was, thus, to analyze lymphocyte parameters of prenatal stressed mice. A footshock stress (0,2 mA, 10 shocks of 5 seconds each/session) was applied both in the final third of gestation and/or in the postnatal adult life. Those stressors was anable to affect the lymphocytes viability and their subpopulation patterns token from peripheral blood; the esplenic lymphocytes proliferation ratio were also not changed. Those results suggested that: 1- the stress model was not effective; 2- the obtained results reflected the absence of an immune challenge applied previous by the experiments performedb; 3- the existence of physiologic redundancies turns the organisms able to react in a homeostatic way even exposed to stress situations.
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Interaction between the renin-angiotensin system and sympathoadrenal axis and its application in the pathogenesis of post-infarction heart remodeling. / CUHK electronic theses & dissertations collectionJanuary 2001 (has links)
Ding Baoguo. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 225-247). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
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Studies on plasma catecholamines in man: analytical techniques and applications.January 1996 (has links)
by Perpetua E. Tan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 149-157). / Abstract --- p.9 / Acknowledgments --- p.12 / List of abbreviations --- p.13 / List of Tables --- p.16 / List of Figures --- p.19 / Chapter CHAPTER 1 --- INTRODUCTION --- p.21 / Chapter CHAPTER 2 --- LITERATURE REVIEWS CATECHOLAMINES: NORADRENALINE AND ADRENALINE --- p.25 / Chapter 2.1 --- History --- p.25 / Chapter 2.2 --- Origin of plasma catecholamines --- p.25 / Chapter 2.3 --- Kinetics of entry and removal --- p.28 / Chapter 2.4 --- Levels present in plasma --- p.30 / Chapter 2.5 --- Some factors affecting plasma CA levels --- p.31 / Chapter 2.5.1 --- Effects of age --- p.31 / Chapter 2.5.2 --- Postural change --- p.32 / Chapter 2.5.3 --- Exercise --- p.32 / Chapter 2.5.4 --- Temperature change --- p.32 / Chapter 2.5.5 --- Stress --- p.33 / Chapter 2.5.6 --- Pregnancy --- p.34 / Chapter 2.5.7 --- Disease --- p.35 / Chapter 2.6 --- Actions in the body --- p.35 / Chapter 2.6.1 --- Plasma endogenous catecholamines --- p.35 / Chapter 2.6.2 --- Plasma exogenous catecholamines and medicine --- p.36 / Chapter 2.6.2.1 --- Clinical uses --- p.36 / Chapter 2.6.2.2 --- Effects --- p.37 / Chapter 2.6.2.3 --- Side effects --- p.38 / Chapter 2.7 --- Binding of catecholamines in plasma --- p.38 / Chapter 2.8 --- Measurement of catecholamines in plasma --- p.38 / Chapter 2.8.1 --- Chemistry --- p.38 / Chapter 2.8.2 --- Extraction and purification --- p.39 / Chapter 2.8.3 --- Biological methods --- p.40 / Chapter 2.8.4 --- Colorimetry --- p.41 / Chapter 2.8.5 --- Radioimmunoassay and radioenzymatic assay --- p.41 / Chapter 2.8.6 --- Enzyme-linked immunoassay --- p.42 / Chapter 2.8.7 --- Gas chromatography --- p.42 / Chapter 2.8.8 --- Liquid chromatography --- p.42 / Chapter 2.8.8.1 --- Fluorometry --- p.43 / Chapter 2.8.8.2 --- Electrochemical detection --- p.43 / Chapter 2.9 --- Plasma protein binding of basic drugs --- p.44 / Chapter 2.9.1 --- Binding to albumin --- p.45 / Chapter 2.9.2 --- Binding to alpha-1-acid-glycoprotein --- p.45 / Chapter 2.9.3 --- Binding to other proteins --- p.45 / Chapter 2.9.4 --- Factors affecting drug binding --- p.46 / Chapter 2.9.4.1 --- Pregnancy --- p.46 / Chapter 2.9.4.2 --- Age --- p.46 / Chapter 2.9.4.3 --- Disease states --- p.46 / Chapter 2.9.5 --- Separation procedures to reveal and follow drug protein binding --- p.47 / Chapter 2.9.5.1 --- Equilibrium dialysis --- p.47 / Chapter 2.9.5.2 --- Ultrafiltration --- p.48 / Chapter 2.9.5.3 --- Ultracentrifugation --- p.48 / Chapter 2.9.5.4 --- Gel Filtration --- p.48 / Chapter CHAPTER 3 --- ANALYTICAL TECHNIQUE : PLASMA CATECHOLAMINE ANALYSIS --- p.49 / Chapter 3.1 --- HPLC determination with coulometric detection of catecholamines --- p.49 / Chapter 3.1.1 --- Introduction --- p.49 / Chapter 3.1.2 --- Basic equipment --- p.49 / Chapter 3.1.3 --- Mobile phase preparation --- p.50 / Chapter 3.1.3.1 --- Reagent A (Citrate-acetate-EDTA buffer) --- p.50 / Chapter 3.1.3.2 --- Reagent B (ion pairing reagent) --- p.50 / Chapter 3.1.3.3 --- Mobile phase mixture --- p.50 / Chapter 3.1.4 --- Detector settings --- p.51 / Chapter 3.1.5 --- Sample collection and storage --- p.51 / Chapter 3.2 --- Reagents and solutions --- p.52 / Chapter 3.2.1 --- Acid-washed alumina --- p.52 / Chapter 3.2.2 --- Tris buffer solution --- p.53 / Chapter 3.2.3 --- Washing solution --- p.53 / Chapter 3.2.4 --- Acetic acid solution --- p.53 / Chapter 3.2.5 --- EDTA-HC1 solution --- p.53 / Chapter 3.2.6 --- Citric acid solution --- p.53 / Chapter 3.2.7 --- Stock solutions --- p.54 / Chapter 3.2.7.1 --- Catecholamine standards --- p.54 / Chapter 3.2.7.2 --- Dihydroxybenzylamine (Internal) standard --- p.54 / Chapter 3.2.8 --- Stripped fresh frozen plasma --- p.54 / Chapter 3.2.9 --- Sorensen's phosphate buffer containing 0.6% NaCl --- p.55 / Chapter 3.2.10 --- Control standards --- p.55 / Chapter 3.3 --- Voltammogram of catecholamines and internal standard used --- p.55 / Chapter 3.4 --- Maintenance of the HPLC-Coulometric detector system --- p.56 / Chapter 3.5 --- Optimization of the extraction method --- p.58 / Chapter 3.5.1 --- Amount of alumina for adsorption of CA --- p.58 / Chapter 3.5.2 --- pH of tris buffer for maximum uptake of CA onto alumina --- p.58 / Chapter 3.5.3 --- Optimum time for maximum uptake of CA onto alumina --- p.59 / Chapter 3.5.4 --- Optimum time for maximum desorption of CA into acid solution --- p.59 / Chapter 3.5.5 --- Optimum volume of acid solution for maximum desorption of CA --- p.60 / Chapter 3.6 --- Validation of the method --- p.60 / Chapter 3.6.1 --- Linearity --- p.60 / Chapter 3.6.2 --- Recovery --- p.61 / Chapter 3.6.3 --- Reproducibility --- p.62 / Chapter 3.6.4 --- Stability --- p.62 / Chapter 3.7 --- Results --- p.63 / Chapter 3.8 --- Discussion --- p.79 / Chapter CHAPTER 4 --- CLINICAL APPLICATIONS OF THE CATECHOLAMINE ASSAY --- p.84 / Chapter 4.1 --- Introduction --- p.84 / Chapter 4.1.1 --- Applications of catecholamines assay in clinical science --- p.84 / Chapter 4.2 --- : PLASMA CATECHOLAMINES AFTER INDUCTION OF ANAESTHESIA AT CAESARIAN SECTION --- p.84 / Chapter 4.2.1 --- Introduction --- p.84 / Chapter 4.2.2 --- Patients and methods --- p.86 / Chapter 4.2.3 --- Blood sampling and storage --- p.87 / Chapter 4.2.4 --- Statistics used --- p.87 / Chapter 4.2.5 --- Results --- p.88 / Chapter 4.2.6 --- Discussion --- p.99 / Chapter 4.3 --- EPINEPHRINE INFILTRATION IN SINUS SURGERY --- p.101 / Chapter 4.3.1 --- Introduction --- p.101 / Chapter 4.3.2 --- Patients and methods --- p.102 / Chapter 4.3.3 --- Blood sampling and storage --- p.103 / Chapter 4.3.4 --- Results --- p.104 / Chapter 4.3.5 --- Discussion --- p.108 / Chapter CHAPTER 5 --- ANALYTICAL TECHNIQUE: PLASMA PROTEIN BINDING OF CATECHOLAMINES --- p.110 / Chapter 5.1 --- Equilibrium dialysis for protein binding of drugs --- p.110 / Chapter 5.1.1 --- Introduction --- p.110 / Chapter 5.1.2 --- Dialyzing apparatus --- p.110 / Chapter 5.1.3 --- Sample collection and storage --- p.111 / Chapter 5.1.4 --- Reagents and solutions --- p.111 / Chapter 5.1.4.1 --- Ascorbic acid --- p.111 / Chapter 5.1.4.2 --- Glutathione --- p.111 / Chapter 5.1.4.3 --- Sodium metabisulfite --- p.111 / Chapter 5.1.4.4 --- Dialysis buffer --- p.111 / Chapter 5.1.5 --- Dialysis membrane --- p.112 / Chapter 5.1.6 --- Equilibrium dialysis --- p.112 / Chapter 5.2 --- Optimization of the binding parameters --- p.113 / Chapter 5.2.1 --- Types of preservatives for stability of catecholamines during dialysis --- p.113 / Chapter 5.2.2 --- Dialysis buffer --- p.114 / Chapter 5.2.3 --- Dialysis time and volume of sample --- p.114 / Chapter 5.2.4 --- Dialysis membrane --- p.115 / Chapter 5.2.5 --- Catecholamines concentration for dialysis --- p.114 / Chapter 5.3 --- Total protein analysis- Lowry Method --- p.115 / Chapter 5.3.1 --- Reagents and solutions --- p.116 / Chapter 5.3.1.1 --- Reagent A (Alkaline copper reagent) --- p.116 / Chapter 5.3.1.2 --- Reagent B (Folin-Ciocalteus phenol reagent with water) --- p.116 / Chapter 5.3.2 --- Stock standard and controls --- p.116 / Chapter 5.3.2.1 --- Human serum albumin standard --- p.116 / Chapter 5.3.2.2 --- Controls --- p.116 / Chapter 5.3.3 --- Procedure --- p.116 / Chapter 5.4 --- Results --- p.117 / Chapter 5.5 --- Discussion --- p.126 / Chapter CHAPTER 6 --- CONCLUSIONS --- p.130 / APPENDIX --- p.134 / CHEMICALS AND REAGENTS --- p.146 / REFERENCES --- p.149
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Estudo dos efeitos da exposição materna à nicotina na lactação sobre a função da medula adrenal e dos adipócitos de ratos machos e fêmeas / Programming of the adrenal function and leptin production by nicotine exposure during lactation: gender differences in ratsCintia Rodrigues Pinheiro 22 February 2011 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Alterações nutricionais, hormonais e ambientais nos períodos críticos do desenvolvimento como a gestação e/ou lactação podem influenciar a estrutura e a fisiologia de órgãos e tecidos, predispondo ao aparecimento de doenças na vida adulta. Esse fenômeno é conhecido como programação metabólica. O fumo materno na gestação/lactação tem sido associado ao sobrepeso/obesidade na infância e na vida adulta em ambos os sexos. Porém, estudos evidenciam diferenças entre os gêneros em resposta a exposição à nicotina. Já foi demonstrado que muitas mulheres param de fumar na gestação, mas a maioria destas volta a fumar na lactação. Anteriormente, mostramos que machos adultos cujas mães foram expostas à nicotina na lactação, desenvolveram obesidade central, hiperleptinemia e hipotireoidismo. Como a nicotina afeta a função adrenal e como catecolaminas e glicocorticóides têm efeitos bem conhecidos sobre o tecido adiposo, avaliamos a função da medula adrenal e o conteúdo de leptina no tecido adiposo e músculo de machos e fêmeas cujas mães foram expostas à nicotina na lactação. Dois dias pós-parto, implantamos minibombas osmóticas nas ratas lactantes dividas em: NIC infusão de nicotina (6mg/Kg/dia s.c.) por 14 dias, e C infusão de salina pelo mesmo período. Estas lactantes foram divididas de acordo com o sexo das proles. O sacrifício das proles de ambos os sexos ocorreu aos 15 (fim da exposição à nicotina) e 180 dias de vida. Aos 15 dias, os machos da prole NIC apresentaram aumento de MGV absoluta e relativa ao peso corporal (+72% e +73% respectivamente), hiperleptinemia (+35%), hipercorticosteronemia (+67%), maior peso adrenal (+39%), conteúdo de catecolaminas totais (absoluto: +69% e relativo: +41%), embora diminuição da enzima TH (-33%). Quando adultos, os machos programados exibiram maior massa corporal (+10%), MGV absoluta (+47%) e relativa (+33%), além de hiperleptinemia (+41%) e maior conteúdo de leptina no TAV (+23%). Esses animais também apresentaram hipercorticosteronemia (+77%), maior conteúdo de catecolaminas totais absoluto e relativo (+79% e +89% respectivamente) e de TH (+38%) embora tenham menor secreção de catecolaminas in vitro estimulada por cafeína (-19%) e maior expressão do ADRB3 no TAV (+59%). Em relação as fêmeas da prole NIC aos 15 dias de vida, estas apresentaram menor massa corporal (-6%) e hiperleptinemia (+41%) embora sem alteração da MGV. Aos 180 dias, as fêmeas da prole NIC apresentaram menor conteúdo de leptina no TAS (-46%) e maior conteúdo de leptina no músculo solear (+22%) e diminuição da expressão do ADRB3 no TAV (-39%). Concluímos que a nicotina materna afeta ambos, medula adrenal e tecido adiposo de forma gênero dependente, tanto em curto prazo (quando a nicotina está presente no leite materno), quanto em longo prazo (repercussões na vida adulta). De forma geral, as fêmeas da prole NIC apresentam alterações mais discretas do que os machos em ambos os períodos estudados. / Nutritional, hormonal and environmental changes during critical periods of life (pregnancy and/or lactation) are associated with future changes in the structure and physiology of body tissues and systems, influencing some diseases in adulthood. This phenomenon is known as metabolic programming. Maternal smoking during pregnancy/lactation has been associated with overweight/obesity in childhood and adulthood in both genders. However, studies have shown gender differences in response to nicotine exposure. Although many women quit smoking during pregnancy, data reveal that most women who stop smoking during gestation relapse during lactation. Previously, we showed that adult male rats whose mothers received nicotine during lactation developed overweight, hyperleptinemia and hypothyroidism. Because nicotine affects the adrenal function and, as glucocorticoids and catecholamines have well known effects on adipose tissue, we evaluated adrenal medulla function and leptin content in adipose tissue and muscle of males and females whose dams were nicotine-treated during lactation. On postnatal (PN) day 2, dams were subcutaneously implanted with osmotic minipumps releasing nicotine (6mg/Kg/day) for 14 days of lactation (NIC) or saline. Male and female offspring were killed at 15 and 180 days-old. In PN15, males of NIC group presented higher absolute (+72%) and relative (+73%) VFM, hyperleptinemia (+35%), hypercorticosteronemia (+67%), higher adrenal weight (+39%) and adrenal catecholamine content (absolute: +69% and relative: +41%) although lower TH content (-33%). In PN180, these males displayed higher body mass (+10%), absolute (+47%) and relative (+33%) VFM, hyperleptinemia (+41%), higher leptin content in VAT (+23%), hypercorticosteronemia (+77%), higher adrenal catecholamine content (absolute:+79% and relative:+89%), higher TH expression (+38%), lower in vitro catecholamine release (-19%) and higher ADRB3 content in VAT (+59%). Females of NIC group at PN15 presented lower body mass (-6%) and hyperleptinemia (+41%) but no change in VFM. In PN180, these females showed lower leptin content in SAT (-46%), higher leptin content in muscle (+22%) and lower ADRB3 content in VAT (-39%). Thus, we evidenced a sex dimorphism in the model of programming by maternal nicotine exposure during lactation. The medullary adrenal function and corticosteronemia in adult rat were programmed only in male offspring while the female offspring displayed relevant alterations in leptin content.
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Effects of Physical and Emotional Stress, Catecholamines and Naloxone on HDL and LDL Cholesterol Levels in Rats and ManGoliszek, Andrew G. 01 May 1983 (has links)
A series of investigations were undertaken to determine whether physical or emotional stress, catecholamines or naloxone (B-endorphon blocker) would increase serum total cholesterol and LDL and HDL levels. Physical stress given daily over a period of time caused a steady increase in serum total cholesterol and LDL without a significantly altering high density lipoproteins (HDL) or serum triglycerides. Daily injections of epinerphrine in oil caused an increase in both serum total cholesterol and LDL levels while daily injections of norepinephrine did not. Reversal of the treatments caused a reversed response in both groups of rats. Similar increases in both total cholesterol and LDL levels occurred in graduate students during preparation for their comprehensive written or oral thesis/dissertation defense.
Injection of eigher dichloroisoproterenol (M.W. = 248) or naloxone (M.W. = 346) in rats prior to stress inhibited the increase in total cholesterol and LDL levels, although naloxone at the dosage given was more effective, possibly due to its larger molecular weight. When naloxone plus epinephrine was injected into non-stressed rats, there was a significant increase in total cholesterol and LDL levels, but the increase was not as great as that of groups injected with epinephrine only. Stressed, adrenalectomized rats exhibited higher cholesterol and LDL levels than the normal reported range for rats of their age and weight, but their levels did not differ from those of stressed, sham-operated rats indicating that the adrenals per se are not needed for stress-induced elevation of blood LDL levels.
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The effects of prenatal hypoxia on postnatal cognitive function : a behavioural, pharmacological and structural analysisCamm, Emily Jane, 1976- January 2002 (has links)
Abstract not available
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Stress Coping Strategies in Rainbow Trout (<i>Oncorhynchus mykiss</i>)Schjolden, Joachim January 2005 (has links)
<p>Animals show a great variety in physiological and behavioural responses to stressors. These responses are often bimodally distributed within populations and show consistency on an individual level over time and across situations, which in terrestrial vertebrates have been identified as proactive and reactive stress coping strategies. Proactive animals show lower cortisol responses, higher sympathetic activation and brain serotonergic activity compared to reactive animals. Behaviourally, proactive animals are more aggressive, more active in avoiding stressors, they form routines and show fewer cases of conditioned immobility compared to reactive animals. Our aim has been to reveal if such stress coping strategies exist in fish. Our results show that rainbow trout with high (HR) or low (LR) cortisol responses to stressors differs in sympathetic activation and brain serotonin turnover in the same manner as proactive and reactive mammals. HR fish showed less locomotor activity when reared in large groups (30 individuals) compared to LR fish. When reared in isolation there were no differences between HR and LR fish when exposed to stressors within a familiar environment. The adaption of a proactive coping style among reactive coping individuals when they are challenged within a familiar environment has previously been shown to be distinction between proactive and reactive coping mammals. However, when they were transferred to unfamiliar environments a behavioural difference between the two lines was observed indicating different stress coping strategies akin to those described in mammals. Finally, we observed a consistency over time in the cortisol response of an unselected line of rainbow trout. Fish from this line also demonstrated a correlation between behavioural responses to different stressors. However, there was no apparent connection between these behavioural responses and the cortisol response. Overall, the results of this thesis have strengthened the hypothesis that different stress coping strategies exist in teleost fish.</p>
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Innervation patterns and locally produced signal substances in the human patellar tendon : of importance when understanding the processes of tendinosisDanielson, Patrik January 2007 (has links)
Tendinosis is a condition of chronic pain that afflicts several human tendons, not least the patellar tendon, in which case it is often clinically referred to as ‘jumper’s knee’. The exact mechanisms behind tendinosis are yet not fully understood. One draw-back in the case of patellar tendinosis has been the lack of knowledge of the innervation patterns of the human patellar tendon. It cannot be excluded that the processes of tendinosis are influenced by nerve mediators, released from nerve endings or from stimulated cells inside the tendon. Thus, the studies of the present thesis aimed to 1) map the general, sensory, cholinergic and sympathetic innervation patterns of the human patellar tendon, in both the tendon tissue proper and the loose paratendinous connective tissue surrounding the tendon, and 2) investigate the possible existence of a production of signal substances, traditionally associated with neurons, in non-neuronal tendon cells, and to see if there are signs of local cholinergic and catecholaminergic signaling pathways. Biopsies of both normal pain-free patellar tendons and patellar tendons from patients with chronic painful tendinosis were collected and investigated. The main method utilized was immunohistochemistry, using antibodies directed against synthesizing enzymes for acetylcholine and catecholamines, against muscarinic and adrenergic receptors, and against markers of general and sensory innervation. In situ hybridization (ISH) to detect mRNA for the cholinergic/catecholaminergic synthesizing enzymes was also used. It was found that the loose paratendinous connective tissue of the patellar tendon was rather richly innervated by nerve structures. These consisted of large nerve fascicles, as well as perivascular innervation in the walls of some of the larger arteries and smaller blood vessels. It was found that part of the nerve structures corresponded to sensory afferents, and that some conformed to cholinergic and, especially, sympathetic nerve fibers. The tendon tissue proper was strikingly less innervated than the paratendinous tissue. The sparse innervation that was found in the tendon tissue proper was seen in narrow zones of loose connective tissue and blood vessels, interspersed between the collagen bundles. The overall impression was that the patterns of distribution of the general, sensory, and autonomic innervations of tendinosis tendon tissue were similar to those of normal tendon tissue proper. The most pioneering findings were the immunohistochemical observations of an expression of enzymes related to production of both acetylcholine and catecholamines within the tendon cells (tenocytes) themselves, as well as of a presence of the receptors for these substances on the same cells; features that were predominantly seen in tendinosis tendons. The observations of the synthesizing enzymes for acetylcholine and catecholamines in tenocytes were confirmed by ISH findings of mRNA for these enzymes in the tenocytes. Immunoreactions for muscarinic and adrenergic receptors were also found in blood vessel walls and in some of the nerve fascicles. In summary, this thesis presents novel information on the innervation patterns of the human patellar tendon, in healthy individuals with pain-free tendons as well as in patients with chronic painful tendinosis. Furthermore, it gives the first evidence of the presence of a local, non-neuronal production in the tendon tissue of signal substances normally seen in neurons, and a basis for these substances to affect the tenocytes as these cells also display muscarinic and adrenergic receptors. Thus, the results indicate an existence of autocrine and/or paracrine cholinergic/catecholaminergic systems in the tendon tissue; systems that seem to be up-regulated in tendinosis. This is of great interest as it is known that stimulation of receptors for both catecholamines and acetylcholine can lead to cell proliferation, interfere with pain sensation, influence collagen production, and take part in vasoregulation, as well as, in the case of adrenergic receptors, promote cell degeneration and apotosis. All these processes represent biological functions/events that are reported to be affected in tendinosis. In conclusion, despite the fact that there is very limited innervation within the patellar tendon tissue proper, it is here shown that effects of signal substances traditionally associated with neurons seem to occur in the tissue, via a local production of these substances in tenocytes.
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Stress Coping Strategies in Rainbow Trout (Oncorhynchus mykiss)Schjolden, Joachim January 2005 (has links)
Animals show a great variety in physiological and behavioural responses to stressors. These responses are often bimodally distributed within populations and show consistency on an individual level over time and across situations, which in terrestrial vertebrates have been identified as proactive and reactive stress coping strategies. Proactive animals show lower cortisol responses, higher sympathetic activation and brain serotonergic activity compared to reactive animals. Behaviourally, proactive animals are more aggressive, more active in avoiding stressors, they form routines and show fewer cases of conditioned immobility compared to reactive animals. Our aim has been to reveal if such stress coping strategies exist in fish. Our results show that rainbow trout with high (HR) or low (LR) cortisol responses to stressors differs in sympathetic activation and brain serotonin turnover in the same manner as proactive and reactive mammals. HR fish showed less locomotor activity when reared in large groups (30 individuals) compared to LR fish. When reared in isolation there were no differences between HR and LR fish when exposed to stressors within a familiar environment. The adaption of a proactive coping style among reactive coping individuals when they are challenged within a familiar environment has previously been shown to be distinction between proactive and reactive coping mammals. However, when they were transferred to unfamiliar environments a behavioural difference between the two lines was observed indicating different stress coping strategies akin to those described in mammals. Finally, we observed a consistency over time in the cortisol response of an unselected line of rainbow trout. Fish from this line also demonstrated a correlation between behavioural responses to different stressors. However, there was no apparent connection between these behavioural responses and the cortisol response. Overall, the results of this thesis have strengthened the hypothesis that different stress coping strategies exist in teleost fish.
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