Angiotensin II (Ang II) promotes vascular disease and hypertension in part by the formation of pro-inflammatory cytokines, oxidative stress and inflammation. Signal transducer and activator of transcription 3 (STAT3) is a transcription factor known to play key roles in cytokine signaling and growth in immune cells. We tested the hypothesis that STAT3 plays an essential role in Ang II-induced vascular dysfunction and hypertension. Responses of carotid arteries from C57BL6 mice were examined in vitro after 22-hour incubation with vehicle or Ang II (10 nM) in the presence or absence of a small molecule inhibitor of STAT3 activation, S3I-201. The endothelium-dependent agonist acetylcholine (Ach) produced relaxation in arteries treated with vehicle and the response was inhibited by ~50% by Ang II (P<0.01). S3I-201 (10 πM) co-incubation prevented the Ang II-induced dysfunction. Relaxation to nitroprusside, an endothelium-independent agonist, was not altered in any group. Ang II increased vascular superoxide more than 2-fold (P<0.05) measured by chemiluminescence. S3I-201 (10 πM) prevented the Ang II induced increase of superoxide. Similar findings were obtained with STATTIC, a second small molecule inhibitor of STAT3 activation. In contrast to these findings, lipopolysaccharide (0.5 πg/ml)-induced endothelial dysfunction was not altered by S3I-201. Blood pressure and responses of carotid arteries and small resistance arteries within the brain were examined in C57BL6 mice with either saline or Ang II (1000 ng/kg/min) infused for 14 days via osmotic minipump, which were also treated with dimethyl sulfoxide (vehicle) or S3I-201 (5 mg/kg, IP, every two days). Infusion with Ang II increased systolic blood pressure compared to saline-infused animals (155±2 and 112±2 mmHg, respectively; P<0.001). S3I-201 reduced pressure slightly in saline infused mice but protected against Ang II-induced increase in pressure at 14 days (102±2 and 114±3 mmHg, respectively). Following systemic treatment with Ang II, carotid artery relaxation responses to Ach were significantly impaired compared to vehicle infused mice (72±3% and 101±1%, respectively, P<0.05). S3I-201 treatment significantly prevented Ang II-induced impairment (94±4%, P<0.05). Ang II treated mice exhibited 55% impaired dilator responses to Ach in small resistance arteries within the brain studied in vitro and S3I-201 treatment prevented most of this impairment (P<0.05). Vasorelaxation to nitroprusside was not altered in any group. In summary, these findings provide the first evidence that STAT3 plays an essential role in Ang II-induced vascular dysfunction and hypertension. Targeting STAT3 with small molecule inhibitors or other approaches may have beneficial effects during hypertension and other disease states in which Ang II contributes to vascular dysfunction (e.g. diabetes and aging).

No description available.

Engineered DNA-binding proteins enable targeted manipulation of the genome. Zinc fingers are the most well characterized DNA-binding domain and for many years research has focused on understanding and manipulating the sequence-specificities of these proteins. Recently, major advances in the ability to engineer zinc finger proteins, as well as the discovery of a new class of DNA-binding domains - transcription activator-like effectors (TALEs), have made it possible to rapidly and reliably engineer proteins targeted to any sequence of interest. With this capability, focus has shifted to exploring the applications of this powerful technology. In this dissertation I explore three important applications of engineered DNA-binding proteins.

Ο σκοπός της παρούσας διατριβής είναι να συμβάλει στην επιλογή του βέλτιστου σπινθηριστή ανάμεσα σε αυτούς που χρησιμοποιούνται στα σύγχρονα απεικονιστικά συστήματα τομογραφίας εκπομπής ποζιτρονίων PET και PET μικρών ζώων, ο οποίος θα μπορούσε να χρησιμοποιηθεί σε ένα ανιχνευτικό σύστημα πολλαπλών εφαρμογών PET/CT, MV CBCT, κλπ.) με έναν κοινό ανιχνευτή. Για το σκοπό αυτό μελετήθηκαν δείγματα από τους ακόλουθους κρυσταλλικούς σπινθηριστές: α) πυριτικού οξειδίου του γαδολινίου (GSO), β) πυριτικού οξειδίου του λουτεσίου (LSO), γ) πυριτικού οξειδίου του λουτεσίου-υτρίου (LΥSO), δ) αλουμινικού οξειδίου του υτρίου (YAP) και ε) αλουμινικού οξειδίου του λουτεσίου-υτρίου (LuYAP). Όλα τα δείγματα των σπινθηριστών ήταν ενεργοποιημένα με τρισθενές δημήτριο (Ce+3). Η μελέτη έγινε σε ευρεία κλίμακα ενεργειών (20kV-18MV). / The aim of this thesis was to select the best scintillator among the ones currently used in PET and animal PET systems, which could be used in a single detector multimodality scanner. To this aim crystal samples of GSO, LSO, LYSO, LuYAP and YAP scintillators, doped with cerium (Ce+3) were examined under a wide energy range (from 20kV-18MV). Measurements concerning determination of absolute efficiency, energy absorption efficiency, intrinsic conversion efficiency, detector optical gain and detector quantum efficiency, giving information on light yield and the intrinsic properties of the scintillators. Information on the compatibility of the light emission spectrum of the scintillators with the currently used optical photon detectors was obtained by calculating the spectral matching factors of each scintillator examined.

Motivation: Hypertension is a fast growing health risk, leading to increased incidences of cardiovascular dysfunction and mortality. However, the prevalence of hypertension is higher in some ethnic populations than others. Several South African studies have found that the African population is more susceptible to the development of hypertension, compared to the Caucasian population. Cardiovascular dysfunction is often accompanied by elevated levels of uric acid (UA) and plasminogen activator inhibitor-I (PAI-1) and both are factors associated with the metabolic syndrome. A lack of data regarding the association of UA and PAL1 with cardiovascular dysfunction in a South African context, serves as a motivation for conducting this study. Objective: To determine the association of UA and PAI-1 with cardiovascular dysfunction in African and Caucasian women from South Africa. Methodology: The manuscript presented in Chapter 2 made use of the data obtained in the POWIRS (Profiles of Obese Women with the Insulin Resistance Syndrome) study. A group of 102 African women and 115 Caucasian women, living in the North West Province of South Africa, were recruited according to their body mass indexes. The groups were divided into lean, overweight and obese according to their body mass index. Anthropometric and cardiovascular measurements were taken and determinations were done of their blood lipid profiles, UA. PAI-1, fasting insulin and glucose levels, HOMA-IR (homeostasis model assessment-insulin resistance) and leptin levels. The subject's total dietary protein intake was determined by means of a dietary questionnaire. Comparisons between the groups were done using an independent t-test as well as a multiple analysis of covariance (MANCOVA) whilst adjusting for certain variables. Each ethnic group was divided into UA and PAI-1 tertiles, for comparison between the 1" and 3' tertiles. Correlation ~0efIi~ientS were determined to show any associations between UA and PAI-1 with cardiovascular variables as well as variables associated with the metabolic syndrome. Forward stepwise multiple regression analyses were performed using UA and PAL1 respectively as dependent variables. The study was approved by the Ethics committee of the North-West University and all the subjects gave informed consent in writing. The reader is referred to the experimental procedure section in Chapter 2 for a more detailed description of the subjects, study design and analytical procedures used in this dissertation. Results and conclusion: Results from the POWIRS-study showed that despite the African women's higher blood pressure, they had significantly lower levels of UA and PAI-I compared to the Caucasian women. Although the Caucasian women had significantly higher circulating levels of UA and PAI-1, they showed no sign of cardiovascular dysfunction. The detrimental effects might, however, become more noticeable with an increase in age. From this study it is concluded that UA and PAL1 is not associated with the increased blood pressure in young African women. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2006.

Elevated plasminogen activator inhibitor (PAI-1) activity levels, hyperlipemia, hypertension, impaired glucose tolerance and obesity, in particular central obesity, are all related to increased risk for the development of cardiovascular disease.Some risk factors are known to be and shown to be influenced by dietary habits. One aim of this study was to determine the distribution of PAI-1 activity and its linkage to serum lipids, body build, glucose and insulin (including glucose tolerance) among healthy men and women. Another aim was to elucidate the effects of different diet programes on the relationship between PAI-1 activity, serum lipid, glucose and insulin levels. Two cross-sectional studies, involving 260 individuals, the Norsjö study 1986, the mean PAI-1 activity among 30-60 year-old men was 7.9 U/mL and among women 7.8 U/mL. Both men and women with a body mass index over 27 kg/m2 had higher PAI-1 activity, tPA antigen, fasting insulin and insulin responses following an oral glucose tolerance test than persons with body mass index &lt;27. They also had lower HDL-cholesterol. Women with a high waist/hip circumference ratio had a higher mean PAI-1 activity, tPA antigen, triglyceride, blood pressure and insulin response to an oral glucose tolerance test than women with low or normal waist/hip ratio. Men with high waist/hip ratio had higher tPA antigen, glucose and insulin responses to an oral glucose tolerance test than men with low or normal waist/hip ratio. In two dietary studies different low-energy diets (a juice fast or a weight reduction program) were followed. PAI-1 activity was decreased in both cases. In a third dietary study, transition from a high-fat/low-carbohydrate diet to a low-fat/high-carbohydrate diet decreased PAI-1 activity provided that it did not also cause a substantial increase in triglycerides or glucose. In a fourth dietary study the regular diet was supplemented with oat-husk. PAI-1 activity was reduced; a small increase in glucose but not in triglyceride levels was observed. On the basis of these results it is concluded that PAI-1 activity levels are associated with constitutional factors such as body mass index and waist/hip ratio. PAI-1 is elevated in obesity. Nutritional factors are also of importance for the PAI-1 activity levels. PAI-1 activity levels can be reduced by dietary regiments such as low-energy diets or high-fiber diets. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1993, härtill 6 uppsatser.</p> / digitalisering@umu

Motivation: Hypertension is a fast growing health risk, leading to increased incidences of cardiovascular dysfunction and mortality. However, the prevalence of hypertension is higher in some ethnic populations than others. Several South African studies have found that the African population is more susceptible to the development of hypertension, compared to the Caucasian population. Cardiovascular dysfunction is often accompanied by elevated levels of uric acid (UA) and plasminogen activator inhibitor-I (PAI-1) and both are factors associated with the metabolic syndrome. A lack of data regarding the association of UA and PAL1 with cardiovascular dysfunction in a South African context, serves as a motivation for conducting this study. Objective: To determine the association of UA and PAI-1 with cardiovascular dysfunction in African and Caucasian women from South Africa. Methodology: The manuscript presented in Chapter 2 made use of the data obtained in the POWIRS (Profiles of Obese Women with the Insulin Resistance Syndrome) study. A group of 102 African women and 115 Caucasian women, living in the North West Province of South Africa, were recruited according to their body mass indexes. The groups were divided into lean, overweight and obese according to their body mass index. Anthropometric and cardiovascular measurements were taken and determinations were done of their blood lipid profiles, UA. PAI-1, fasting insulin and glucose levels, HOMA-IR (homeostasis model assessment-insulin resistance) and leptin levels. The subject's total dietary protein intake was determined by means of a dietary questionnaire. Comparisons between the groups were done using an independent t-test as well as a multiple analysis of covariance (MANCOVA) whilst adjusting for certain variables. Each ethnic group was divided into UA and PAI-1 tertiles, for comparison between the 1" and 3' tertiles. Correlation ~0efIi~ientS were determined to show any associations between UA and PAI-1 with cardiovascular variables as well as variables associated with the metabolic syndrome. Forward stepwise multiple regression analyses were performed using UA and PAL1 respectively as dependent variables. The study was approved by the Ethics committee of the North-West University and all the subjects gave informed consent in writing. The reader is referred to the experimental procedure section in Chapter 2 for a more detailed description of the subjects, study design and analytical procedures used in this dissertation. Results and conclusion: Results from the POWIRS-study showed that despite the African women's higher blood pressure, they had significantly lower levels of UA and PAI-I compared to the Caucasian women. Although the Caucasian women had significantly higher circulating levels of UA and PAI-1, they showed no sign of cardiovascular dysfunction. The detrimental effects might, however, become more noticeable with an increase in age. From this study it is concluded that UA and PAL1 is not associated with the increased blood pressure in young African women. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2006.

Motivation Soluble urokinase plasminogen activator receptor (suPAR) is a known inflammatory marker, which is found in various body fluids. SuPAR reflects the immune and pro–inflammatory status of patients caused by HIV and tuberculosis, amongst others. However, recent studies have shown that suPAR is related to cardiovascular function. The cardiovascular health of the black South African population is a major health concern as this group suffers mostly from hypertension and stroke, leading to an alarming increase in cardiovascular morbidity and mortality. SuPAR may be able to contribute to early detection and prevention of cardiovascular diseases. No studies regarding the associations of suPAR with cardiovascular function have been investigated on black South Africans. Objectives To investigate suPAR as a possible marker of cardiovascular function in African and Caucasian men and women, by determining possible gender and ethnic–specific associations of suPAR with cardiovascular function. Methodology There were 207 African and 314 Caucasian men and women (aged 20–79 yrs.) included in this study. High–sensitivity C–reactive protein, glucose, lipids and creatinine were determined in fasting serum and suPAR was analyzed in plasma samples. Blood pressure was measured using the OMRON apparatus (HEM–747), with a 5–min rest interval between measurements. The Finometer device was used to determine the Windkessel compliance and the carotid dorsalis–pedis pulse wave velocity (PWV) was measured with the Complior (SP acquisition system) on the left side of each subject in the supine position. The means, adjusted means and proportions were compared between the groups by using independent t–tests, analysis of co–variance and the chi–square test, respectively. Associations were investigated between cardiovascular variables and suPAR using single and multiple regression analyses with either pulse wave velocity, systolic blood pressure, diastolic blood pressure or Windkessel compliance as dependent variable. Covariates included were age, body mass index, smoking, alcohol use, physical activity, glucose and high–density lipoprotein cholesterol. Results and conclusion SuPAR levels were significantly higher in Africans (P<0.001) compared to Caucasians. After adjusting for body mass index, suPAR increased significantly with age in all groups, except for African women. Moreover, the suPAR levels of African men and women were significantly higher than the Caucasians within each age quartile. While adjusting for age and body mass index, the cardiovascular profiles of the African and Caucasian men were less favourable compared to women, but suPAR levels were significantly higher in Caucasian women compared to men. In single regression, various measures of cardiovascular function correlated with suPAR in African men and Caucasian men and women. After adjusting for confounders the associations disappeared in Caucasian women, and remained nonsignificant in the African women. However, the association between PWV and suPAR remained significant in African men (B=0.19; P=0.030), while the association of systolic blood pressure (B=0.20; P=0.017), diastolic blood pressure (B=0.17; P=0.020) and Windkessel compliance (B=–0.14; P=0.004) with suPAR remained significant in Caucasian men. In conclusion, Africans presented higher suPAR levels compared to Caucasians, even when stratified by age. Gender specific associations indicated that suPAR was associated with arterial stiffness in African and Caucasian men only, therefore, indicating that suPAR could be a possible biomarker for predicting cardiovascular dysfunction. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2011.

Motivation Soluble urokinase plasminogen activator receptor (suPAR) is a known inflammatory marker, which is found in various body fluids. SuPAR reflects the immune and pro–inflammatory status of patients caused by HIV and tuberculosis, amongst others. However, recent studies have shown that suPAR is related to cardiovascular function. The cardiovascular health of the black South African population is a major health concern as this group suffers mostly from hypertension and stroke, leading to an alarming increase in cardiovascular morbidity and mortality. SuPAR may be able to contribute to early detection and prevention of cardiovascular diseases. No studies regarding the associations of suPAR with cardiovascular function have been investigated on black South Africans. Objectives To investigate suPAR as a possible marker of cardiovascular function in African and Caucasian men and women, by determining possible gender and ethnic–specific associations of suPAR with cardiovascular function. Methodology There were 207 African and 314 Caucasian men and women (aged 20–79 yrs.) included in this study. High–sensitivity C–reactive protein, glucose, lipids and creatinine were determined in fasting serum and suPAR was analyzed in plasma samples. Blood pressure was measured using the OMRON apparatus (HEM–747), with a 5–min rest interval between measurements. The Finometer device was used to determine the Windkessel compliance and the carotid dorsalis–pedis pulse wave velocity (PWV) was measured with the Complior (SP acquisition system) on the left side of each subject in the supine position. The means, adjusted means and proportions were compared between the groups by using independent t–tests, analysis of co–variance and the chi–square test, respectively. Associations were investigated between cardiovascular variables and suPAR using single and multiple regression analyses with either pulse wave velocity, systolic blood pressure, diastolic blood pressure or Windkessel compliance as dependent variable. Covariates included were age, body mass index, smoking, alcohol use, physical activity, glucose and high–density lipoprotein cholesterol. Results and conclusion SuPAR levels were significantly higher in Africans (P<0.001) compared to Caucasians. After adjusting for body mass index, suPAR increased significantly with age in all groups, except for African women. Moreover, the suPAR levels of African men and women were significantly higher than the Caucasians within each age quartile. While adjusting for age and body mass index, the cardiovascular profiles of the African and Caucasian men were less favourable compared to women, but suPAR levels were significantly higher in Caucasian women compared to men. In single regression, various measures of cardiovascular function correlated with suPAR in African men and Caucasian men and women. After adjusting for confounders the associations disappeared in Caucasian women, and remained nonsignificant in the African women. However, the association between PWV and suPAR remained significant in African men (B=0.19; P=0.030), while the association of systolic blood pressure (B=0.20; P=0.017), diastolic blood pressure (B=0.17; P=0.020) and Windkessel compliance (B=–0.14; P=0.004) with suPAR remained significant in Caucasian men. In conclusion, Africans presented higher suPAR levels compared to Caucasians, even when stratified by age. Gender specific associations indicated that suPAR was associated with arterial stiffness in African and Caucasian men only, therefore, indicating that suPAR could be a possible biomarker for predicting cardiovascular dysfunction. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2011.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.