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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.
101

Evolutionary Patterns and Occurrences of the fish Viral Hemorrhagic Septicemia Virus in the Laurentian Great Lakes

Niner, Megan 06 September 2019 (has links)
No description available.
102

Development and evaluation of an automated system to deliver a live-attenuated Edwardsiella ictaluri vaccine in commercial catfish production systems

Lowe, John Wesley 13 December 2019 (has links)
Catfish aquaculture is the largest cultured food fish industry in the United States, accounting for approximately $375 million in sales annually, with Mississippi leading the industry with 36,200 surface acres of production. However, infectious diseases such as enteric septicemia of catfish (ESC) are decreasing production efficiencies, creating losses of $40-60 million annually. Live-attenuated oral ESC vaccines are effective in preventing ESC infections, but have not been widely adopted by the catfish industry due to the lack of a system to administer the oral vaccine at the scale seen in commercial catfish production systems. An automated system was developed to administer a dosage of 220.5 ml of a live-attenuated ESC vaccine per kg of catfish feed, adapting commercial catfish feeder design to include a screw conveyor for mixing vaccine and feed in a continuous process, pulse-width modulated spray nozzle control for precise vaccine application, and a programmable automation controller to regulate and monitor system performance. Initial performance evaluations demonstrated system operation within the desired design specifications. System feed rates were determined to be a function of the rotational speed (RPM) of the screw conveyor and to be linear across the operational range. Feed rates were observed to decrease by 45% over dry feed when applying liquid vaccine to the feed stream at the 220.5 ml/kg (100 ml/lb) rate, resulting in a feed rate range of 6.80-34.02 kg/min (15-75 lb/min) (95% CI). Uniform pellet-level vaccine distribution is crucial to efficacy as pellet consumption is directly correlated with fish size, with more criticality in smaller fish fed at low rates. Pellet vaccine concentrations at 6.80, 20.41, and 34.02 ml/kg were highly variable and vaccine application at all rates were observed to be statistically different (less) than the target 220.5ml/kg rate (95% CI), pointing to potential issues with vaccine delivery system configuration or inadequacies in sampling methodology. Further evaluation at the pellet level with live-attenuated vaccine to obtain viable cell counts within individual pellets would provide data necessary to address uniformity of coverage questions more fully and to develop operational protocols that maximize system capabilities and vaccine efficacy.
103

Pathogen Entrance And Development Of Disease During Infection Of The American Channel Catfish Ictalurus Punctatus By The Enterobacterium Edwardsiella Ictaluri

Menanteau-Ledouble, Simon 11 December 2009 (has links)
Since being first reported in the late 1980ies, the Enterobacterium Edwardsiella ictaluri has rose in prevalence to become one of the two most damaging pathogens affecting the channel catfish industry. Despite this significance of the pathogen, understanding of the development of the disease, especially its route of entry into the host and the earlier stages of the infection, is still incomplete. A series of challenges were conducted using bioluminescent E. ictaluri either by infecting fish through immersion or topical application of the bacteria directly on the intact or abraded epithelium. This showed that abraded fish developed septicemia and died faster than non-abraded ones. Furthermore, results from a co-habitation challenge suggested that the bacterium induced septicemia through the skin instead of becoming water-borne. Finally, a histological technique was developed allowing the determination that the bacteria radiated from the initial skin infection site and penetrated deeper into the tissue as the challenge progressed. These results all suggest that site of abrasion on the skin can act as a route of entrance for the pathogen into the fish, a fact never previously reported. Transposon mutagenesis was also performed to construct a library of 1728 mutants. Screening of this library allowed us to identify 16 genes which inactivation lead to a decrease in the bacterium ability to colonize the epithelium or cause mortality. Sequencing of these genes allowed the identification of RstA/B, a regulator of invasion genes in Salmonella enterica Typhimurium, a putative ribonuclease, similar to a Shigella protein regulating the expression of adhesin and a protein that constitutes the second member of a newly discovered adhesin family. Finally, to investigate the development of the infection, fish were infected by bioluminescent E. ictaluri and sampled at various time points. At each time point, nine organs (gills, muscles, intestine, spleen, liver, stomach, heart, head kidney and trunk kidney) were sampled, and their bioluminescence was measured and half of these organs were homogenized, serial diluted, and plate counts determined. This allowed confirmation of a complex disease pathogenesis during ESC involving a period of intense reproduction in the spleen, anterior and posterior kidneys followed by a sharp increase in the levels of bacteria in the blood.
104

Viral Hemorrhagic Septicemia virus (VHSv) Infection in Lake Erie Yellow Perch, Perca flavescens, and its Effect on Feeding

Bergquist, Gregory M. 24 August 2012 (has links)
No description available.
105

Studies on Host-Virus interaction for Viral Hemorrhagic Septicemia Virus (VHSv)

Pore, Adam 27 September 2012 (has links)
No description available.
106

Epidemiologia das infecções de corrente sanguínea por enterobactérias produtoras de betalactamase de espectro expandido: estudo caso-controle em Unidade Neonatal do Norte do Brasil

SILVA, Danille Lima da January 2012 (has links)
Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-10-17T13:53:14Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EpidemiologiaInfeccoesCorrente.pdf: 766099 bytes, checksum: 05ecc342e2ed41b2ef10f89f10b2c8a1 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-10-25T14:47:32Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EpidemiologiaInfeccoesCorrente.pdf: 766099 bytes, checksum: 05ecc342e2ed41b2ef10f89f10b2c8a1 (MD5) / Made available in DSpace on 2017-10-25T14:47:33Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EpidemiologiaInfeccoesCorrente.pdf: 766099 bytes, checksum: 05ecc342e2ed41b2ef10f89f10b2c8a1 (MD5) Previous issue date: 2012 / Bacilos gram-negativos, em especial enterobactérias, estão entre os agentes mais comuns de sepse neonatal. O objetivo desta pesquisa foi estudar as infecções de corrente sanguínea (ICS) por enterobactérias produtoras de betalactamase de espectro expandido (ESBL) em pacientes internados em unidade neonatal da região norte do Brasil. Estudo retrospectivo, caso-controle de neonatos admitidos em unidade neonatal, entre 01 janeiro de 2007 e 31 de dezembro de 2011, com ICS tardia com hemoculturas positivas para Klebsiella sp., Serratia sp., Enterobacter sp. ou E. coli, isoladas, segundo os critérios do National Committee for Clinical Laboratory Standards. Foram identificados 153 neonatos com ICS por enterobactéria, dos quais 87 (56,8%) estavam infectados por enterobactéria produtora de ESBL, com incidência de 8,6 casos para cada 1000 recém-nascidos admitidos. Foram estudados 132 pacientes, divididos em casos (ESBL +) e controles (ESBL -), com 66 em cada (1:1). A maioria dos casos foi acometida nos primeiros dias de vida (34,8% vs. 9,1%, p=0,001), principalmente em 2007 (19,7%) e fez uso de dois antibióticos (59,1% vs. 33,3%, p=0,01). O grupo controle fez mais uso de cateter venoso central (62,1% vs. 45,4%, p= 0,037) e de nutrição parenteral (75,7% vs. 48,5%). A curva de distribuição de enterobactérias de acordo com a produção de ESBL evidenciou maior número de casos em 2007 e 2008 (56%), com uma maior chance de aquisição de enterobactéria ESBL (+) nestes anos (78% e 72%, respectivamente), e maior número de isolados ESBL negativo em 2010 e 2011 (72,7%). A evolução a óbito foi maior entre os casos (40,9% vs. 24,2%, p= 0,031) e a maioria morreu até 30 dias após o episódio de ICS (92,6% vs. 50,0%, p= 0,002). Na análise multivariada, a evolução a óbito por ESBL positivo permaneceu como variável independente (OR=3,47 IC 1,33 – 9,06). Concluiu-se que houve uma maior incidência de ICS por enterobactéria produtora de ESBL nos dois primeiros anos do estudo (2007 – 2008), com probabilidade de aquisição deste tipo de infecção de até 78%. A mortalidade neonatal foi elevada, sendo três vezes maior quando comparada a infecções por enterobactérias sensíveis. A mudança do perfil de resistência das enterobactérias, com redução do número de casos de infecção por ESBL ao longo do tempo foi resultado da implementação de medidas de controle de disseminação e seleção de resistência bacteriana na unidade neonatal, e coincidiu com a revisão dos protocolos assistenciais, como maior utilização de cateter central de inserção percutânea e protocolo de nutrição parenteral no período de 2010 e 2011. / Gram-negative bacilli, especially Enterobacteriacea, are frequently associated with neonatal sepsis. A retrospective case-control study was performed to study bloodstream infections (BSI) caused by extended-spectrum beta-lactamase-producing (ESBL) enterobacteria in a neonatal unit the northern region of Brazil. This research was undertaken of all neonates admitted between 1st January 2007 and 31st December 2011 to the neonatal care unit, who had late-onset sepsis with blood cultures positive for Klebsiella sp., Enterobacter sp., Serratia sp. and Escherichia coli, performed according to National Committee for Clinical Laboratory Standards criteria. There were 153 neonates with gram-negative septicaemia, 87 newborns were infected with ESBL-producing enterobacteria, with incidence of 8.63 cases per 1000 newborns admitted. These were studied 132 patients, divided in two groups, cases (ESBL +) and controls (ESBL -), of 66 each (1:1). Most cases were affected in the first days of life (34,8% vs. 9,1%, p=0,001), especially in 2007 (19,7%), and made use two antibiotics (59,1% vs. 33,3%, p=0,01). The control group made more use of central venous catheter (62,1% vs. 45,4%, p=0,037) and parenteral nutrition (75,7% vs. 48,5%, p=0,001). The distribution curve of enterobacteria in accordance with the production of ESBL throughout the study period showed a greater number of cases in 2007 and 2008 (56,05%), with a higher chance of acquiring ESBL-producing enterobacteria these years (78% e 72%, respectively), and a higher number of controls for 2010 and 2011 (72,7%). The evolution to more deaths occurred among the cases (40,9% vs. 24,2%, p=0,031) and the majority died within 30 days of the episode of ICS (92,6% vs. 50,0%, p=0,002). In multivariate analysis, the evolution to death by ESBL-producing remained as an independent variable (OR=3,47 IC 1,33 – 9,06). It was concluded that there was a higher incidence of ESBL-producing enterobacteria BSI for the first two years of the study (2007 - 2008), with probability of acquiring this type of infection of up to 78%. The neonatal mortality was high, being three times greater when compared to infections by non-ESBL-producing enterobacteria. The change of the resistance profile of BSI by enterobacteria, reducing the number of cases of ESBL over time was a result of the implementation of control measures for dissemination and selection of bacterial resistance in the neonatal unit, and coinciding with the revision of care protocols as increased use of PICC and parenteral nutrition protocol in the period from 2010 to 2011.
107

Cortisol perturbation in the pathophysiology of septicaemia, complicated pregnancy and weight loss/obesity.

Ho, Jui Ting. January 2007 (has links)
Cortisol, the principal glucocorticoid secreted from the adrenal glands, is essential for life. Healthy cortisol levels are maintained through negative feedback on the central nervous system (CNS) – pituitary stimulatory apparatus which regulates production of adrenocorticotropin (ACTH) and contains a light–entrained intrinsic CNS driven diurnal rhythm. Cortisol participates in a regulatory mechanism where inflammatory cytokines stimulate cortisol release and cortisol in turn suppresses cytokine release. The effects of cortisol in inflammatory states include elevating blood pressure and metabolic regulation. This thesis contains three exploratory studies examining circulating cortisolaemia using the best available methodologies (total and free cortisol and corticosteroid-binding globulin (CBG)) in clinical states characterized by immune activation/ inflammation and altered blood pressure. These clinical states include: (1) septic shock, (2) hypertensive disorders of pregnancy and (3) obesity-induced hypertension. Prior to the studies described here, little was know about cortisolaemia in these common pathological states. Septic shock is a life threatening condition that complicates severe infection and is characterized by systemic inflammation and refractory hypotension. High plasma total cortisol levels and attenuated responses to synthetic ACTH stimulation are associated with increased mortality. The use of corticosteroids in septic shock has been highly controversial for decades, however recent trials have reported haemodynamic and survival benefits associated with the use of physiologic steroid replacement in patients with relative adrenal insufficiency (RAI) – currently defined as a total cortisol increment of 248 nmol/L or less following ACTH (250 μg) stimulation. However, CBG and albumin levels fall by around 50% with an increase in plasma free cortisol in critical illness. Hence, total cortisol may not reflect the biologically active free (unbound) cortisol, suggesting that standard assays for plasma cortisol (which measure total plasma cortisol) underestimate HPA axis activity. In this study, we have showed that plasma free cortisol is a better guide to circulating glucocorticoid activity in systemic infection than total cortisol. We have also validated the use of Coolens’ method in estimating free cortisol in systemic infection, using plasma total cortisol and CBG measurements as plasma free cortisol is not performed in clinical laboratories. Free cortisol measurement allows better categorization of RAI and non-RAI groups with a free cortisol increment of 110 nmol/L as cut-off. Moreover, we have shown that survivors of RAI have normal adrenocortical function on follow-up testing suggesting a lack of functional adrenal reserve rather than adrenal damage during critical illness. Larger randomized controlled trials will be required to redefine RAI using free cortisol measurements and relate that to clinical outcomes and responses to corticosteroid therapy. Nitric oxide (NO) is normally produced in the endothelium by the constitutive form of the NO synthase and this physiologic production is important for blood pressure regulation and blood flow distribution. Studies have shown that an overproduction of NO by the inducible form of NO synthase (iNOS) may contribute to the hypotension, cardiodepression and vascular hyporeactivity in septic shock. Clinical studies of non-selective inhibitors of the L-arginine nitric oxide pathway showed increased mortality from cardiovascular complications. However, glucocorticoids, which improve vasopressor sensitivity, may act by partially suppressing NO synthesis through selective direct inhibition of iNOS, and suppression of inflammatory cytokine synthesis. Hence, plasma nitrate/ nitrite (NOx) levels may provide a titratable end point to individualize glucocorticoid therapy in sepsis. The NOx study in this thesis showed that cortisol (total and free), CBG and NOx correlated to illness severity. Free cortisol, and to a lesser extent total cortisol, but not NOx levels, predicted septic shock. NOx levels were characteristically stable within individuals but inter-individual differences were only partly accounted for by illness severity or renal dysfunction. NOx levels correlated weakly with cortisol, did not relate to the need for vasopressors and were not suppressed by hydrocortisone treatment. Thus, NOx is not a suitable target for glucocorticoid therapy in septic shock. Pregnancy is the only sustained physiologic state of hypercortisolism in humans. A large body of data suggests that excessive foetal and prenatal glucocorticoid exposure leads to reduced birth weight and adverse health in offspring such as elevated blood pressure and insulin resistance. Pre-eclampsia and gamete donor pregnancies are associated with immune activation, elevated inflammatory cytokines as well as elevated blood pressure. Prior to the study described in this thesis however, there was no prospective data on maternal cortisolaemia in these complicated pregnancies. My study has demonstrated for the first time that there was a substantial fall in plasma CBG levels in the last few weeks of gestation with a corresponding rise in free cortisol in normal pregnancy, a finding obscured for methodological reasons in past studies. This free cortisol elevation in late pregnancy may facilitate organ maturation in the foetus and perhaps prepare the mother for the metabolic demands of labour. In pre-eclampsia and gestational hypertension, plasma CBG, total and free cortisol levels were lower in late third trimester; and in IUGR, plasma CBG levels were suppressed from 28 weeks gestation until delivery but with no significant difference in plasma total and free cortisol. Women with assisted reproduction using donor gametes/ embryos had significantly lower plasma CBG, total and free cortisol levels even in those with normal pregnancy outcomes. Low CBG may be due to reduced synthesis or enhanced inflammation-driven degradation. Low maternal cortisol may be due to a lack of placental corticotropin-releasing hormone, or reduced maternal ACTH, driving cortisol production. This unanticipated maternal hypocortisolism in complicated pregnancies may trigger precocious activation of the foetal HPA axis and could have implications for postnatal and adult health. Speculatively, since excess prenatal GCs increase HPA axis activity, we proposed that maternal hypocortisolism may predispose to the hypocortisolaemic state characterized by fatigue, pain and stress sensitivity, in offspring. The third state of immune/ inflammatory activation associated with blood pressure dysregulation studied in this thesis is obesity. The epidemiologic relationship between obesity and hypertension is widely recognised. Central obesity in particular has been associated with exaggerated HPA responses to stimuli. Studies of severe dieting and starvation resulted in hypercortisolism and a significant decrease in CBG. The HPA axis and the renin-angiotensin-aldosterone system (RAAS) have been implicated in the pathophysiology of obesity-induced hypertension. However, there is little data on the effect of moderate weight loss (30% caloric restriction) on adrenocortical function, and the relation of adrenal hormones to altered blood pressure with weight loss. In this study, measures of HPA axis and RAAS and blood pressure monitoring were performed in twenty-five obese subjects before and after a 12-week diet program (6000kJ/day). Short-term, moderate weight loss (mean 8.5 kg) was associated with a small reduction in blood pressure (mean arterial pressure 6 mmHg) and significantly reduced levels of aldosterone and renin but not cortisol levels. These findings suggest that aldosterone may have an important role in the blood pressure reduction with weight loss via a renin mediated mechanism, perhaps involving renal sympathetic tone. In contrast to severe caloric restriction, HPA axis activation does not occur with moderate weight loss. This suggests a threshold effect of weight loss on the HPA axis where greater caloric restriction is required for HPA stimulation, or a counterbalancing of central and direct adrenal effects on HPA axis function. Overall, these three exploratory studies have provided novel data on HPA axis function in systemic infection, pregnancy and in diet-induced weight loss. Each study offers a basis for further studies of HPA axis function in these disorders. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1289330 / Thesis(Ph.D.)-- School of Medicine, 2007.
108

Cortisol perturbation in the pathophysiology of septicaemia, complicated pregnancy and weight loss/obesity.

Ho, Jui Ting. January 2007 (has links)
Cortisol, the principal glucocorticoid secreted from the adrenal glands, is essential for life. Healthy cortisol levels are maintained through negative feedback on the central nervous system (CNS) – pituitary stimulatory apparatus which regulates production of adrenocorticotropin (ACTH) and contains a light–entrained intrinsic CNS driven diurnal rhythm. Cortisol participates in a regulatory mechanism where inflammatory cytokines stimulate cortisol release and cortisol in turn suppresses cytokine release. The effects of cortisol in inflammatory states include elevating blood pressure and metabolic regulation. This thesis contains three exploratory studies examining circulating cortisolaemia using the best available methodologies (total and free cortisol and corticosteroid-binding globulin (CBG)) in clinical states characterized by immune activation/ inflammation and altered blood pressure. These clinical states include: (1) septic shock, (2) hypertensive disorders of pregnancy and (3) obesity-induced hypertension. Prior to the studies described here, little was know about cortisolaemia in these common pathological states. Septic shock is a life threatening condition that complicates severe infection and is characterized by systemic inflammation and refractory hypotension. High plasma total cortisol levels and attenuated responses to synthetic ACTH stimulation are associated with increased mortality. The use of corticosteroids in septic shock has been highly controversial for decades, however recent trials have reported haemodynamic and survival benefits associated with the use of physiologic steroid replacement in patients with relative adrenal insufficiency (RAI) – currently defined as a total cortisol increment of 248 nmol/L or less following ACTH (250 μg) stimulation. However, CBG and albumin levels fall by around 50% with an increase in plasma free cortisol in critical illness. Hence, total cortisol may not reflect the biologically active free (unbound) cortisol, suggesting that standard assays for plasma cortisol (which measure total plasma cortisol) underestimate HPA axis activity. In this study, we have showed that plasma free cortisol is a better guide to circulating glucocorticoid activity in systemic infection than total cortisol. We have also validated the use of Coolens’ method in estimating free cortisol in systemic infection, using plasma total cortisol and CBG measurements as plasma free cortisol is not performed in clinical laboratories. Free cortisol measurement allows better categorization of RAI and non-RAI groups with a free cortisol increment of 110 nmol/L as cut-off. Moreover, we have shown that survivors of RAI have normal adrenocortical function on follow-up testing suggesting a lack of functional adrenal reserve rather than adrenal damage during critical illness. Larger randomized controlled trials will be required to redefine RAI using free cortisol measurements and relate that to clinical outcomes and responses to corticosteroid therapy. Nitric oxide (NO) is normally produced in the endothelium by the constitutive form of the NO synthase and this physiologic production is important for blood pressure regulation and blood flow distribution. Studies have shown that an overproduction of NO by the inducible form of NO synthase (iNOS) may contribute to the hypotension, cardiodepression and vascular hyporeactivity in septic shock. Clinical studies of non-selective inhibitors of the L-arginine nitric oxide pathway showed increased mortality from cardiovascular complications. However, glucocorticoids, which improve vasopressor sensitivity, may act by partially suppressing NO synthesis through selective direct inhibition of iNOS, and suppression of inflammatory cytokine synthesis. Hence, plasma nitrate/ nitrite (NOx) levels may provide a titratable end point to individualize glucocorticoid therapy in sepsis. The NOx study in this thesis showed that cortisol (total and free), CBG and NOx correlated to illness severity. Free cortisol, and to a lesser extent total cortisol, but not NOx levels, predicted septic shock. NOx levels were characteristically stable within individuals but inter-individual differences were only partly accounted for by illness severity or renal dysfunction. NOx levels correlated weakly with cortisol, did not relate to the need for vasopressors and were not suppressed by hydrocortisone treatment. Thus, NOx is not a suitable target for glucocorticoid therapy in septic shock. Pregnancy is the only sustained physiologic state of hypercortisolism in humans. A large body of data suggests that excessive foetal and prenatal glucocorticoid exposure leads to reduced birth weight and adverse health in offspring such as elevated blood pressure and insulin resistance. Pre-eclampsia and gamete donor pregnancies are associated with immune activation, elevated inflammatory cytokines as well as elevated blood pressure. Prior to the study described in this thesis however, there was no prospective data on maternal cortisolaemia in these complicated pregnancies. My study has demonstrated for the first time that there was a substantial fall in plasma CBG levels in the last few weeks of gestation with a corresponding rise in free cortisol in normal pregnancy, a finding obscured for methodological reasons in past studies. This free cortisol elevation in late pregnancy may facilitate organ maturation in the foetus and perhaps prepare the mother for the metabolic demands of labour. In pre-eclampsia and gestational hypertension, plasma CBG, total and free cortisol levels were lower in late third trimester; and in IUGR, plasma CBG levels were suppressed from 28 weeks gestation until delivery but with no significant difference in plasma total and free cortisol. Women with assisted reproduction using donor gametes/ embryos had significantly lower plasma CBG, total and free cortisol levels even in those with normal pregnancy outcomes. Low CBG may be due to reduced synthesis or enhanced inflammation-driven degradation. Low maternal cortisol may be due to a lack of placental corticotropin-releasing hormone, or reduced maternal ACTH, driving cortisol production. This unanticipated maternal hypocortisolism in complicated pregnancies may trigger precocious activation of the foetal HPA axis and could have implications for postnatal and adult health. Speculatively, since excess prenatal GCs increase HPA axis activity, we proposed that maternal hypocortisolism may predispose to the hypocortisolaemic state characterized by fatigue, pain and stress sensitivity, in offspring. The third state of immune/ inflammatory activation associated with blood pressure dysregulation studied in this thesis is obesity. The epidemiologic relationship between obesity and hypertension is widely recognised. Central obesity in particular has been associated with exaggerated HPA responses to stimuli. Studies of severe dieting and starvation resulted in hypercortisolism and a significant decrease in CBG. The HPA axis and the renin-angiotensin-aldosterone system (RAAS) have been implicated in the pathophysiology of obesity-induced hypertension. However, there is little data on the effect of moderate weight loss (30% caloric restriction) on adrenocortical function, and the relation of adrenal hormones to altered blood pressure with weight loss. In this study, measures of HPA axis and RAAS and blood pressure monitoring were performed in twenty-five obese subjects before and after a 12-week diet program (6000kJ/day). Short-term, moderate weight loss (mean 8.5 kg) was associated with a small reduction in blood pressure (mean arterial pressure 6 mmHg) and significantly reduced levels of aldosterone and renin but not cortisol levels. These findings suggest that aldosterone may have an important role in the blood pressure reduction with weight loss via a renin mediated mechanism, perhaps involving renal sympathetic tone. In contrast to severe caloric restriction, HPA axis activation does not occur with moderate weight loss. This suggests a threshold effect of weight loss on the HPA axis where greater caloric restriction is required for HPA stimulation, or a counterbalancing of central and direct adrenal effects on HPA axis function. Overall, these three exploratory studies have provided novel data on HPA axis function in systemic infection, pregnancy and in diet-induced weight loss. Each study offers a basis for further studies of HPA axis function in these disorders. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1289330 / Thesis(Ph.D.)-- School of Medicine, 2007.
109

Adjunctive therapies in an ovine model of septic shock due to fecal peritonitis / Therapeutic approaches to severe sepsis and septic shock

Su, FUHONG 24 May 2007 (has links)
Sepsis remains a severe issue in critically ill patients. Adjunctive therapies might play important role to decrease morbidity and mortality. The aim of this thesis is to investigate new adjunctive therapies role in the treatment of sepsis and septic shock. / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished
110

Innate and adaptive immune responses of channel catfish to Edwardsiella ictaluri wild type and live attenuated vaccine candidates

Erdogan, Ozgur 07 August 2020 (has links)
Edwardsiella ictaluri causes enteric septicemia of catfish (ESC), a devastating disease in the channel catfish industry. Our research group has developed several E. ictaluri live attenuated vaccine (LAV) candidates (EiΔevpB, EiΔevpBΔfur, EiΔevpBΔhfq, EiΔevpBΔfurΔhfq), which were able to stimulate an immune response in vaccinated channel catfish and reduce ESC. However, innate, and adaptive immune responses in the lymphoid tissues of channel catfish to these LAVs are not known well. The overall goal of the project is to determine the role of adaptive and innate immune responses in catfish after vaccination with LAVs. Analysis of innate and adaptive immune-related gene expressions showed that the LAVs induced expression of adaptive immune-related genes in lymphoid tissues with less inflammation compared to wild type control. Also, the LAVs induced the expression of IgM in the sera of catfish.

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