The present study examined the hemodynamic response to recreational hockey (n= 22) in middle-aged men (53±6 yrs). Study participants were equipped with ambulatory blood pressure and heart rate monitoring equipment prior to a weekly hockey games. Participants were monitored throughout the duration of their hockey game for “On-Ice” responses and during seated bench time (“Bench”), and for a brief period afterwards. On-Ice HR’s and blood pressures were significantly higher than values obtained during maximal cycle exercise (HR 174±8.9 vs. 163±11.0 bpm) (SBP 17%; DBP 15%) (p<0.05), Blood pressures decreased throughout the duration of the game while HR increased significantly. The On-Ice endocardial viability ratio (EVR), an index of myocardial oxygen supply and demand, did not change from early (1.56±0.05) to late (1.44± 0.06) in the game. In conclusion, recreational hockey is an extremely vigorous form of interval exercise that produces cardiovascular responses exceeding intensities commonly recommended for continuous training.

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Background: Nurses are responsible for the monitoring and assessment of blood pressure in the clinical setting. Increasing evidence has demonstrated that inaccurate measurement technique often leads to the misclassification of large numbers of individuals as hypertensive. The impact of untreated or poorly treated hypertension, due to misclassification of patients, is a major contributor to the overall burden of adult diseases in any population. Accurate measurement of blood pressure relies on knowledge and skill and is considered paramount in the management of cardiovascular risks. There seems to be limited information on the knowledge and skill of nurses in South Africa regarding the correct measurement of BP when using a sphygmomanometer and the auscultatory method. Given South Africa’s primary healthcare philosophy, and the significant role that nurses play in the prevention and treatment of hypertension, it is of importance to investigate nurses’ knowledge and skill of blood pressure measurement. Objectives: (i) to determine nurses’ skill and knowledge in measuring blood pressure using a sphygmomanometer and auscultation, and (ii) to determine if there is a correlation between nurses’ skill and knowledge of blood pressure measurement technique. Design and method: This study followed a quantitative, descriptive design with an observational checklist and survey method. In phase one, nurses’ skills of blood pressure measurement using a sphygmomanometer was determined by means of an observation checklist. In phase two, the researcher determined nurses’ knowledge of blood pressure measurement technique by using a standardised set of questions. Finally, the researcher investigated whether there was a correlation between nurses’ knowledge and their skill of blood pressure measurement technique in the mentioned setting. Results: Overall, the mean score for correctly completing the skills on the observational checklist was 87.7%. Nurses’ scored an average of 63.1% for knowledge of blood pressure measurement technique. The relationship between the assessment of skills and performance on the written questionnaire on knowledge was not significant (r=0,062, p=0,5). Conclusions: Although the average scores were 87.7% for skills and 63.1% for knowledge, this study identified deficts in both the knowledge and to a lesser degree, in the skill of nurses to understand and perform blood pressure measurement. Regular updates and carrying readily available documents on the standardized procedure for BP measurement techniques could support the training and correction of nurses’ knowledge and skill in the acute setting. Educational preparation that is more detailed may also greatly contribute to more understanding and knowledge of blood pressure for nurses involved in the diagnosis and treatment of cardiovascular risk. / MCur, North-West University, Potchefstroom Campus, 2014

Background: Nurses are responsible for the monitoring and assessment of blood pressure in the clinical setting. Increasing evidence has demonstrated that inaccurate measurement technique often leads to the misclassification of large numbers of individuals as hypertensive. The impact of untreated or poorly treated hypertension, due to misclassification of patients, is a major contributor to the overall burden of adult diseases in any population. Accurate measurement of blood pressure relies on knowledge and skill and is considered paramount in the management of cardiovascular risks. There seems to be limited information on the knowledge and skill of nurses in South Africa regarding the correct measurement of BP when using a sphygmomanometer and the auscultatory method. Given South Africa’s primary healthcare philosophy, and the significant role that nurses play in the prevention and treatment of hypertension, it is of importance to investigate nurses’ knowledge and skill of blood pressure measurement. Objectives: (i) to determine nurses’ skill and knowledge in measuring blood pressure using a sphygmomanometer and auscultation, and (ii) to determine if there is a correlation between nurses’ skill and knowledge of blood pressure measurement technique. Design and method: This study followed a quantitative, descriptive design with an observational checklist and survey method. In phase one, nurses’ skills of blood pressure measurement using a sphygmomanometer was determined by means of an observation checklist. In phase two, the researcher determined nurses’ knowledge of blood pressure measurement technique by using a standardised set of questions. Finally, the researcher investigated whether there was a correlation between nurses’ knowledge and their skill of blood pressure measurement technique in the mentioned setting. Results: Overall, the mean score for correctly completing the skills on the observational checklist was 87.7%. Nurses’ scored an average of 63.1% for knowledge of blood pressure measurement technique. The relationship between the assessment of skills and performance on the written questionnaire on knowledge was not significant (r=0,062, p=0,5). Conclusions: Although the average scores were 87.7% for skills and 63.1% for knowledge, this study identified deficts in both the knowledge and to a lesser degree, in the skill of nurses to understand and perform blood pressure measurement. Regular updates and carrying readily available documents on the standardized procedure for BP measurement techniques could support the training and correction of nurses’ knowledge and skill in the acute setting. Educational preparation that is more detailed may also greatly contribute to more understanding and knowledge of blood pressure for nurses involved in the diagnosis and treatment of cardiovascular risk. / MCur, North-West University, Potchefstroom Campus, 2014

Resetting of baroreceptor afferent firing in hypertensive animals, and the reduction in baroreflex regulation of the heart rate seen in man, are thought to be secondary to changes in vascular distensibility in hypertension. Diminished baroreflex sensitivity should be reflected in a withdrawal of inhibition of sympathetic nervous function. This hypothesis was investigated in 62 hypertensive subjects using three indirect indices of sympathetic nervous activity: (1) the haemodynamic responses to mental and physical exercise, (2) plasma noradrenaline concentrations at rest, and on exercise, and (3) the beat-to-beat variability of waking ambulatory blood pressure. Subjects with diminished baroreflex sensitivity (1) achieved higher maximum mean arterial blood pressures during four different exercises, and greater absolute increases in blood pressure when bicycling, (2) tended (P<O.O6) to have higher plasma noradrenaline concentrations when bicycling, and (3) exhibited greater variability of their waking mean arterial pressure. It was concluded that subjects with reduced baroreflex sensitivity were less able to buffer acute changes in blood pressure, and inhibit sympathetic efferent activity, particularly when somatic afferents were also activated, as in physical exercise. The time course and extent of changes in baroreflex sensitivity, in relation to changes in the heart and (by inference from previous work) the peripheral vasculature, during the development and reversal of 2-kidney 1-clip Goldblatt hypertension was investigated in rats. A reduction in baroreflex sensitivity occurred within three days of renovascular hypertension, before the occurrence of cardiovascular changes and resetting of the threshold for carotid sinus activation. Baroreflex sensitivity returned to normal one day after the reversal of renovascular hypertension, at a time when these structural changes were still present. It was concluded that 'non-structural', rather than 'structural' factors were responsible for the reduction in baroreflex sensitivity during the initial stages of renovascular hypertension.

Little is known of the temporal cerebral blood flow response to a chemical stimulus consisting of increased PCO2 measured over time. Currently, there is only one study suggesting multiple phases in the CBF-CO2 response. Time constants of middle cerebral artery blood velocity (MCAV) response to a change in PETCO2 have been reported to be between 3 and 99.4 s. We studied the MCAV response in 28 subjects (10 females) to a sustained +10 mmHg above baseline (10 min) acute increase of PETCO2. We found that there were three distinct MCAV response patterns among subjects. Additionally, the responses of males and females differed. These studies suggest that there are multiple overlapping mechanisms controlling the chemoresponse of cerebral blood vessels and that these mechanisms may differ between men and women.

Little is known of the temporal cerebral blood flow response to a chemical stimulus consisting of increased PCO2 measured over time. Currently, there is only one study suggesting multiple phases in the CBF-CO2 response. Time constants of middle cerebral artery blood velocity (MCAV) response to a change in PETCO2 have been reported to be between 3 and 99.4 s. We studied the MCAV response in 28 subjects (10 females) to a sustained +10 mmHg above baseline (10 min) acute increase of PETCO2. We found that there were three distinct MCAV response patterns among subjects. Additionally, the responses of males and females differed. These studies suggest that there are multiple overlapping mechanisms controlling the chemoresponse of cerebral blood vessels and that these mechanisms may differ between men and women.

Pain sensitivity is typically reduced in individuals with higher blood pressure although the nature of this relationship is poorly understood. Relatedly, the ingestion of sweet tasting solutions has been shown to reduce pain, possibly by an opioid mediated mechanism. The objective of the present research was to investigate the effects of blood pressure and sweet taste on pain sensitivity in healthy adults. The first aim was to test whether blood pressure interacts with sweet taste to affect pain sensitivity. The second aim was to test whether endogenous opioids mediate the effects of sweet taste and blood pressure on pain. In Study One, participants held sweet, bitter and plain water solutions in their mouths during exposure to a painful cold pressor test. Replicating previous research, individuals with higher blood pressure were found to have generally higher pain tolerance than those with lower blood pressure. Sweet taste was associated with an increase in pain tolerance but only in individuals with lower range blood pressure, increasing their tolerance to the level of those with higher blood pressure. In Study Two, participants held sweet solution, plain water or nothing in their mouths during cold pressors on two days. To test the involvement of endogenous opioids, participants were administered an opioid antagonist on one of the test days. Participants with higher resting blood pressure again showed increased tolerance and reduced unpleasantness ratings of the pain tasks, as well as dampened mood reactivity to the testing. In these individuals, the opioid antagonist reduced their pain tolerance and partially reversed their lower mood reactivity. As in Study One, sweet taste increased pain tolerance in participants with lower but not higher blood pressure, but this was unaffected by opioid blockade. Taken together these results suggest some overlap between non-opioid mechanisms of sweet taste and blood pressure related analgesia. These results are also consistent with work suggesting that endogenous opioid activity may play a role in the reduced pain sensitivity, and perhaps mood reactivity, of individuals with higher blood pressure and that multiple processes are involved in blood pressure-related hypoalgesia.

The epithelial sodium channel (ENaC) is the central component of the sodium absorption pathway in epithelia. It is critical for sodium homeostasis and blood pressure control, which is demonstrated by rare genetic disorders such as Liddle�s syndrome and pseudohypoaldosteronism type I, that are associated with hyper- and hypotension, respectively. ENaC is mainly regulated by mechanisms that control the expression of active channels at the cell surface. Ubiquitin ligases of the Nedd4-like family, such as Nedd4 and Nedd4-2 decrease epithelial sodium absorption by binding to and targeting ENaC for endocytosis and degradation. This is most likely achieved by catalyzing the ubiquitination of ENaC. Conversely the serum- and glucocorticoid regulated kinase (SGK) increases ENaC activity. This effect is partly mediated by the interaction of SGK with the ubiquitin ligases Nedd4 and Nedd4-2. SGK is able to bind to both Nedd4 and Nedd4-2, however only Nedd4-2 is phosphorylated by SGK. The phosphorylation of Nedd4-2 inhibits its interaction with ENaC, thus reducing ENaC ubiquitination, thereby increasing surface expression and sodium absorption. Nedd4-like proteins interact with ENaC via their WW-domains. These domains bind PY-motifs (PPXY) present in ENaC subunits. Nedd4 and Nedd4-2 both have four highly similar WW-domains. Previous studies have shown that interaction between Nedd4 and ENaC is mainly mediated by WW-domain 3. SGK also has a PY-motif; therefore it was analyzed whether the WW-domains of Nedd4 and Nedd4-2 mediate binding to SGK. Here, it is shown that single or tandem WW-domains of Nedd4 and Nedd4-2 mediate binding to SGK and that, despite their high similarity, different WW-domains of Nedd4 and Nedd4-2 are involved. These data also suggest that WW-domains 2 and 3 of Nedd4-2 mediate the interaction with SGK in a concerted manner, and that in vitro the phosphorylation of SGK at serine residue 422 increases its affinity for the WW-domains of Nedd4-2. The stimulatory effect of SGK on ENaC activity is partly mediated via Nedd4-2 and will decrease if competition between Nedd4 and Nedd4-2 for binding to SGK occurs. Here it is shown that Nedd4 and Nedd4-2 are located in the same subcellular compartment and that they compete for binding to SGK. Besides its function in the proteasomal degradation pathway ubiquitination is involved in the regulation of membrane protein trafficking, including their endocytosis. ENaC was shown previously to be ubiquitinated. Here, we provide evidence that ENaC can be ubiquitinated differentially depending on its cellular location. Channels residing in the plasma membrane are multiubiquitinated and we suggest that this serves as an internalization signal for ENaC and a control for further trafficking. Cytosolic ENaC is mainly polyubiquitinated, and therefore probably targeted for proteasomal degradation. However, mono- and multiubiquitination of ENaC located within the cytosol is very likely to occur as well. In addition, it is shown that both proteasomal and lysosomal pathways are involved in the regulation of ENaC.