HESI exams: an overview of reliability and validity

Schools of nursing are increasingly administering computerized exams developed by Health Education Systems, Inc (HESI) to evaluate student and program outcomes and provide evidence-based rationale for curriculum development and modification. This article describes the methods used to establish the reliability and validity of HESI specialty exams and HESI exit exams. Discussion of current reliability and validity findings and recommendations for future research to enhance the quantification of validity data for HESI exams are presented.     

Cardiorespiratory and cerebrovascular responses to head-up tilt II: Influence of age, training status and acute exercise

The purpose of this study was to examine the combined cardiorespiratory and cerebrovascular responses to head-up tilt (HUT) in young and older trained and untrained humans following moderate-duration exercise. Middle cerebral artery blood flow velocity (MCAv; transcranial Doppler ultrasound), blood pressure (BP; Finometer), and stroke volume (SV) were measured continuously whilst supine and during 60° HUT for 15 min or to pre-syncope in 41 participants [nine young trained; eleven young untrained; twelve older trained; nine older untrained] prior to and following 30 min of treadmill exercise at 70-80% maximal HR. Orthostatic tolerance was not reduced following exercise [Mean (all groups) 14:45 ± 1:19, vs. 14:47 ± 0:43 min:s (before exercise); P = 0.73], and did not differ with age or fitness. Mean MCAv was elevated [~ 5 ± 11%] whilst supine after exercise in the older participants but reduced [~−4 ± 12%] in the young [P = 0.03]. The postural reductions in MCAv [~−22% vs. -17%; P = 0.02], MAP [~−8% vs. −3%; P = 0.04] and SV [~−28% vs. −23%; P = 0.03] were increased after exercise (vs. pre-exercise). Orthostatic tolerance was not reduced following 30 min of exercise, and did not differ with age or fitness, despite more pronounced post-exercise reductions in MCAv, MAP and SV with postural change.     

Neuromechanical features of the cardiac baroreflex after exercise

A single bout of exercise is associated with postexercise hypotension, transient decreases in autonomic function, and changes in baroreflex sensitivity. The baroreflex is less sensitive to falling blood pressure than to rising blood pressure; we characterized the cardiac baroreflex in terms of hysteresis and its mechanical and neural components. We hypothesized that hysteresis would be exacerbated postexercise because of a greater relative decrease in falling blood pressure. In 10 healthy young humans (5 men), we used bolus injections of sodium nitroprusside and phenylephrine hydrochloride to drive transient decreases and increases in blood pressure, respectively, to quantify cardiac baroreflex sensitivity to falling and rising blood pressure. This was completed before and at 10, 30, and 60 minutes after 40 minutes of cycling at 60% estimated maximal oxygen consumption. Analyses of beat-to-beat blood pressure, R-R intervals and heart rate, and carotid artery diameter were used to determine the integrated cardiac baroreflex response; this was further quantified into a mechanical component (systolic blood pressure versus carotid diameter) and a neural component (carotid diameter versus R-R interval). There were 2 principle findings: after aerobic exercise baroreflex sensitivity is reduced and hysteresis manifests, and the reduction in sensitivity to falling blood pressure is mediated by decreased mechanical and neural gains, whereas the decreased baroreflex sensitivity to rising blood pressure is mediated by a reduced mechanical gain only. We suggest that impaired neural transduction of the cardiac baroreflex, and its influence on hysteresis, plays an important role in transient autonomic dysfunction after exercise.     

The relationship between addiction and reward bundling: an experiment comparing smokers and non-smokers

Aims Previous studies indicate that addicts show reduced preference for more delayed versus more immediate rewards compared to non‐addicts. This may reflect a lower propensity to view such decisions in terms of the larger sequences to which they typically belong (e.g. smoking is a frequently repeated act). Therefore, this study aims to test whether, in a sequence of decisions involving smaller, sooner (SS) versus larger, later (LL) rewards, suggesting or forcing people with a propensity to addiction to make the decision for the series as a whole would increase LL preference. It is hypothesized that people without a propensity to addiction should benefit less from being encouraged to think of reward sequences because they already tend to take that view. Design Thirty regular smokers (as exemplars of addicted individuals) and 30 non‐smokers chose between small short‐term and larger long‐term monetary rewards over a sequence of four decisions spaced 2 weeks apart. Subjects were divided into three groups: one who made each decision independently with no suggestion that they be considered as a series (‘free’), a group to whom it was suggested from the start that they consider each decision as part of the series (‘suggested’) and a group who were told that their very first choice in the series would be used for the remaining decisions (‘forced’). All subjects were paid the amounts they had chosen. Setting A laboratory room at the University of Cape Town (UCT). Participants UCT undergraduate volunteers. Analyses The proportion of LL choices in each subgroup was evaluated by χ² tests and a probit model. Findings Smokers increased their preference for LL rewards when ‘bundling’ of individual decisions into a sequence was either suggested or forced. This preference increased with repeated experience. Non‐smokers showed neither pattern. Conclusions The propensity of smokers to prefer small short‐term rewards over larger delayed rewards may be mitigated, over a sequence of decisions of this kind, by encouraging or forcing them to think of the sequence as a whole. If replicated, this finding may form the basis of an intervention that could attenuate the choice patterns characteristic of addiction.     

Transition to adult care for pediatric liver transplant recipients: the Western Australian experience

Transition to adult care is a vulnerable period for pediatric transplant recipients and is associated with reduced medication compliance, graft loss, and increased mortality. Psychosocial outcomes in young adults differ between pediatric transplant recipients and their healthy peers. We conducted a single‐center, retrospective cohort study of all pediatric liver transplant recipients who were transitioned through our center. This study aimed to assess the outcomes of transitioned pediatric liver transplant recipients at an Australian center, including mortality, adherence, and psychosocial morbidity. The 1‐ and 5‐year survival rates following transition were 100% and 92%, respectively. There were no episodes of late rejection. In total, 66.7% of patients were compliant with immunosuppression and 61.1% of patients were compliant with clinic attendance. There was a significant relationship between medication compliance and clinic attendance, as well as presence of psychological issues with clinic non‐attendance. Psychosocial outcomes were in keeping with age‐matched data from the general population. All patients were employed or studying following transition. This is the first study of its kind in the Australian population, and outcomes were superior to published international data. Despite the demonstrated good outcomes, transition programs may improve healthcare engagement in this cohort.     

Saquinavir Loaded Acetalated Dextran Microconfetti – a Long Acting Protease Inhibitor Injectable

Purpose

Since the adoption of highly active antiretroviral therapy, HIV disease progression has slowed across the world; however, patients are often required to take multiple medications daily of poorly bioavailable drugs via the oral route, leading to gastrointestinal irritation. Recently, long acting antiretroviral injectables that deliver drug for months at a time have moved into late phase clinical trials. Unfortunately, these solid phase crystal formulations have inherent drawbacks in potential dose dumping and a greater likelihood for burst release of drug compared to polymeric formulations.

Methods

Using electrospinning, acetalated dextran scaffolds containing the protease inhibitor saquinavir were created. Grinding techniques were then used to process these scaffolds into injectables which are termed saquinavir microconfetti. Microconfetti was analyzed for in vitro and in vivo release kinetics.

Results

Highly saquinavir loaded acetalated dextran electrospun fibers were able to be formed and processed into saquinavir microconfetti while other polymers such as poly lactic-co-glycolic acid and polycaprolactone were unable to do so. Saquinavir microconfetti release kinetics were able to be tuned via drug loading and polymer degradation rates. In vivo, a single subcutaneous injection of saquinavir microconfetti released drug for greater than a week with large tissue retention.

Conclusions

Microconfetti is a uniquely tunable long acting injectable that would reduce the formation of adherence related HIV resistance. Our findings suggest that the injectable microconfetti delivery system could be used for long acting controlled release of saquinavir and other hydrophobic small molecule drugs.

     

The effects of ageing and passive heating on cardiorespiratory and cerebrovascular responses to orthostatic stress in humans

We tested the hypothesis that older adults, relative to younger adults, would be more prone to critical reductions in cerebral blood flow and oxygenation upon standing during passive heat stress. Six older (70+/-4 years, mean+/-s.d.) and six younger males (29+/-4 years) were heated (oesophageal temperature raised 0.5 degrees C) in a water-perfused suit. Blood flow velocity in the middle cerebral artery (MCAv), cerebral oxygenation, mean arterial pressure (MAP) and end-tidal partial pressure of carbon dioxide (PET,CO2) were measured continuously before and during 3 min standing in each thermal state. At supine normothermic baseline, MCAv was 47% lower in older participants (P<0.001), whilst MAP and cerebral oxygenation were similar between groups (P>0.05). Heating lowered the supine MAP more in younger adults, and elevated heart rate only in this group. Upon initial standing in normothermia, older participants had a greater drop in MCAv (P<0.05 versus young), a lesser drop in MAP (approximately 24 and approximately 42% in older and younger participants, respectively), but slower recovery of MAP (27.3+/-6.8 versus 18.6+/-4.7 s, mean+/-s.d., P=0.004); heating did not exacerbate any postural responses in either age group. During the last minute of standing, MCAv and PET,CO2 were lower in older participants, though age differences were not evident in cerebral oxygenation (normothermic or heated). Thus, independent of heat stress, in addition to lower resting MCAv, there are further age-related reductions in MCAv and slower corrections of MAP following standing. However, these asymptomatic changes seem to represent a physiologically acceptable insult which can be well tolerated in otherwise healthy older participants even during heat stress.     

Trans-generational exposure to low levels of rhodamine B does not adversely affect litter size or liver function in murine mucopolysaccharidosis type IIIA

MPS IIIA is a lysosomal storage disorder caused by mutations in the sulphamidase gene, resulting in the accumulation of heparan sulphate glycosaminoglycans (HS GAGs). Symptoms predominantly manifest in the CNS and there is no current therapy that effectively addresses neuropathology in MPS IIIA patients. Recent studies in MPS IIIA mice have shown that rhodamine B substrate deprivation therapy (SDT) (also termed substrate reduction therapy/SRT) inhibits GAG biosynthesis and, improves both somatic and CNS disease pathology. Acute overexposure to high doses of rhodamine B results in liver toxicity and is detrimental to reproductive ability. However, the long-term effects of decreasing GAG synthesis, at the low dose sufficient to alter neurological function are unknown. A trans-generational study was therefore initiated to evaluate the continuous exposure of rhodamine B treatment in MPS IIIA mice over 4 generations, including treatment during pregnancy. No alterations in litter size, liver histology or liver function were observed. Overall, there are no long-term issues with the administration of rhodamine B at the low dose tested and no adverse effects were noted during pregnancy in mice.