Hyperammonemia in patients receiving valproic acid in the hospital setting: A retrospective review

Introduction

Valproic acid (VPA) is widely used for the treatment of epilepsy, migraine, and a variety of psychiatric conditions. The reported incidences of hyperammonemia induced by VPA use is variable. The purpose of this study is to evaluate the incidence of VPA-induced hyperammonemia in the general adult inpatient population.

Methods

Adult patients who received at least 1 dose of VPA and derivatives between June 1, 2017 to December 31, 2017 were included. Patients were excluded if they did not have VPA administered during their inpatient stay or if they had elevated ammonia levels (>33 μmol/L) prior to initiation of VPA. Patients with a confirmed diagnosis of liver cirrhosis were also excluded. The primary endpoint was the incidence of hyperammonemia. Secondary outcomes included symptoms of hyperammonemia, diagnosis of VPA-induced hyperammonemia, and treatment of VPA-induced hyperammonemia.

Results

A total of 162 patients were included in this study. A total of 33 (20.4%) patients were identified as having the primary outcome of hyperammonemia; 26 (16.0%) patients had symptoms of hyperammonemia, and 13 (8.0%) patients were diagnosed with VPA-induced hyperammonemia. Treatment modalities included administration of lactulose, levocarnitine, discontinuing VPA, or decreasing the VPA dose.

Discussion

The administration of VPA in the general adult inpatient population resulted in a 20.4% incidence of hyperammonemia, with a lower rate of diagnosed VPA-induced hyperammonemia. Clinicians should be encouraged to obtain ammonia levels in patients receiving VPA if symptoms of altered mental status or encephalopathy develop.

A design and focus group evaluation of dietary choices tools for an underserved population

Introduction:

Our objective was to develop and evaluate dietary teaching tools for a select population diagnosed with a severe mental illness and limited financial ability. Patients with severe mental illnesses face many challenges, including common health comorbidities of diabetes, high blood pressure, high cholesterol, and obesity. Cognitive deficits may limit educational programming; financial resources can affect access to a healthy diet. The Integrated Multidisciplinary Program of Assertive Community Treatment (IMPACT) program, a university-based program, provides individualized services to this population. One focus is healthy nutritional choices.

Methods:

In Phase One, a clinical pharmacist and a first-year pharmacy resident created visual aids. These cards were given to health care providers (HCPs) to be used with IMPACT members. HCPs were asked to participate in a focus group and provide feedback. Phase Two: Based on specific focus group feedback, additional resources were created to address identified nutritional needs.

Results:

Phase One: Ten cards were created and distributed to the HCPs. A focus group was conducted. HCPs reported the cards were useful in opening dietary choices dialogues and were able to give more specific information on alternative choices. Phase Two: From focus group feedback, specific cards for disease states, calorie guidelines, and budget limitations were developed. HCPs immediately utilized them.

Discussion:

This pilot project was used to design and create educational cards to facilitate discussions on healthy or healthier dietary choices. Feedback from the HCPs participating in the focus group was positive, and they were enthusiastic about both sets of cards, particularly those pertaining to budget choices.

Perceived anxiety and plasma cortisol concentrations following rock climbing with differing safety rope protocols

OBJECTIVES

To examine how different safety rope protocols impact on subjective anxiety and self-confidence levels and plasma cortisol concentrations and the relationship between subjective states and cortisol during rock climbing.

METHODS

Participants (n = 12) were tested in three climbing conditions that were designed to invoke low, moderate and high physical and mental stress. Plasma cortisol concentrations were collected before and after climbing and participants reported subjective anxiety and self-confidence states for each climb.

RESULTS

Repeated measures analysis of variance showed significant differences between conditions for somatic anxiety (F(2, 22) = 7.74, p = 0.009), self-confidence (F(2, 22) = 9.52, p = 0.001) and change in plasma cortisol concentration (F(2, 22) = 3.71, p = 0.041). Preplanned polynomial comparisons showed that these were linear effects; somatic anxiety was higher in the higher stress conditions whilst self-confidence was lower. Plasma cortisol concentration change was also linear. Regression analyses showed cubic relationships between plasma cortisol concentration and cognitive anxiety (R(2) = 0.452), self-confidence (R(2) = 0.281) and somatic anxiety (R(2) = 0.268).

CONCLUSIONS

There is a relationship between plasma cortisol concentration and subjective anxiety and self-confidence states during rock climbing. Changes in the way the safety rope is organised can impact on anxiety, cortisol concentration and self-confidence during rock climbing.

Creatine supplementation, sleep deprivation, cortisol, melatonin and behavior

The effect of creatine supplementation and sleep deprivation, with intermittent moderate-intensity exercise, on cognitive and psychomotor performance, mood state, effort and salivary concentrations of cortisol and melatonin were examined. Subjects were divided into a creatine supplementation group and a placebo group. They took 5 g of creatine monohydrate or a placebo, dependent on their group, four times a day for 7 days immediately prior to the experiment. They undertook tests examining central executive functioning, short-term memory, choice reaction time, balance, mood state and effort at baseline and following 18-, 24- and 36-h sleep deprivation, with moderate intermittent exercise. Saliva samples were taken prior to each set of tests. A group x time analysis of covariance, with baseline performance the covariate, showed that the creatine group performed significantly (p < 0.05) better than the placebo group on the central executive task but only at 36 h. The creatine group demonstrated a significant (p < 0.01) linear improvement in performance of the central executive task throughout the experiment, while the placebo group showed no significant effects. There were no significant differences between the groups for any of the other variables. A significant (p < 0.001) main effect of time was found for the balance test with a linear improvement being registered. Cortisol concentrations on Day 1 were significantly (p < 0.01) higher than on Day 2. Mood significantly (p < 0.001) deteriorated up to 24 h with no change from 24 to 36 h. Effort at baseline was significantly (p < 0.01) lower than in the other conditions. It was concluded that, during sleep deprivation with moderate-intensity exercise, creatine supplementation only affects performance of complex central executive tasks.

Warm-up prior to undertaking a dynamic psychomotor task: does it aid performance?

AIM

The purpose of this study was to examine the effect of differing types of warm-up on the performance of a psychomotor skill that required quick reaction and movement times (MTs), and whole-body co-ordination.

METHODS

Subjects (n=12) carried out a psychomotor task which involved reacting to 1 of 3 lights, then running through a slalom course before kicking a mini-soccer ball at a target. The task was completed following rest, a physical warm-up, a skill-specific warm-up and a skill plus physical warm-up. In the physical, and skill plus physical warm-ups the subjects cycled on an ergometer at a workload calculated to induce exercise at their lactate threshold. The outcome dependent variables were time to initiate a movement (reaction time), time to complete the slalom run (MT) and two measures of passing accuracy(constant error and variable error. Biomechanical variables(knee, hip and ankle angles, and horizontal and vertical ankle velocities at contact(were also compared.

RESULTS

A repeated measures analysis of variance showed no significant effect of warm-up type on any of the dependent variables. Stepwise multiple regression analyses showed that changes in heart rate from resting values to those before performance of the skill test (D HR pre-performance) and those after performance of the test (D HR post-performance) combined were significant predictors of MT (R(2)=0.31, P<0.001), while D HR post-performance significantly predicted reaction time (R(2)=0.12, P<0.02).

CONCLUSIONS

It was concluded that warm-up provided no significant benefit in performance for a task that was dynamic in nature but that physical arousal probably aids reaction and MTs.

Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol

RATIONALE

Sleep deprivation has a negative effect on cognitive and psychomotor performance and mood state, partially due to decreases in creatine levels in the brain. Therefore, creatine supplementation should lessen the negative effects of sleep deprivation.

OBJECTIVES

The objective of this study was to examine the effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol.

METHOD

Subjects were divided into a creatine group (n=10) and a placebo group (n=9). They took 5 g of creatine monohydrate or a placebo, dependent on their group, four times a time a day for 7 days, immediately prior to the experiment. The study was double blind. Subjects undertook tests of random movement generation (RMG), verbal and spatial recall, choice reaction time, static balance and mood state pre-test (0 h), after 6, 12 and 24 h of sleep deprivation, with intermittent exercise. They were tested for plasma concentrations of catecholamines and cortisol at 0 and 24 h.

RESULTS

At 24 h, the creatine group demonstrated significantly less change in performance from 0 h (delta) in RMG, choice reaction time, balance and mood state. There were no significant differences between groups in plasma concentrations of catecholamines and cortisol. Norepinephrine and dopamine concentrations were significantly higher at 24 h than 0 h, but cortisol were lower.

CONCLUSIONS

Following 24-h sleep deprivation, creatine supplementation had a positive effect on mood state and tasks that place a heavy stress on the prefrontal cortex.

Effect of incremental exercise on initiation and movement times in a choice response, whole body psychomotor task

OBJECTIVES

To examine how exercise at moderate and maximal intensities affects performance on a choice response time, whole body psychomotor task.

METHODS

Subjects (n = 12) were tested on a three-choice response time task, after rest and after exercise at 70% and 100% maximum power output (W*max). The dependent variables were time to begin forward momentum (initiation time) and time to complete the movement (movement time). Stride time for the first and second strides and number of strides to cover first 1.1 m were also measured. Blood lactate concentrations and heart rate were recorded before and after completion of each psychomotor test. The subjects subjectively assessed the amount of effort that they used to complete the task.

RESULTS

Repeated measures analysis of variance showed a significant effect for initiation (F2,22 = 11.47, p < 0.001) and movement times (F2,22 = 14.61, p < 0.001). Post hoc least significant difference (LSD) tests showed that initiation time after exercise at 70% W*max was significantly faster than that in the other two conditions. Speed of initiation after rest was significantly quicker than that after exercise at W*max. For movement time, LSD tests showed that time after maximal exercise was significantly slower than that in the other two conditions. Stride time for the second stride showed a significant effect (F2,22 = 6.20, p < 0.01). LSD tests found that time after exercise at W*max was significantly slower in the other two conditions. Stepwise multiple regression analyses found that the increment of change, from rest, of lactate concentrations could significantly predict the increment of change in initiation (R2 = 0.40) and movement (R2 = 0.50) times.

CONCLUSIONS

Exercise affects a whole body task differently from purely cognitive tasks. Central factors are probably more important than peripheral factors.

Supra-maximal effort and reaction and movement times in a non-compatible response time task

AIM

The primary purpose of this study was to examine the effect of attempting to exercise supra-maximally on reaction time and movement time in a non-compatible response time task.

METHODS

Subjects (n=9) undertook a 4-choice non-compatible response time test at rest, while cycling at 70 rpm with a resistance of 35 W (low intensity exercise), cycling at 70% of their maximum power output (MPO), cycling at 100% MPO and attempting to cycle at 70 rpm, with a resistance that was 28 W greater than the resistance required to elicit MPO (supra-maximal effort).

RESULTS

Reaction time, movement time, intra-individual variations in reaction time and movement time at each exercise intensity were compared by a series of repeated measures analyses of variance. A significant effect of exercise was shown for movement time, F(4,32)=6.05, p<0.001, eta2=0.44, Power=0.97 and intra-individual variation in reaction time, F(4,32)=4.98, p<0.005, eta2=0.38, Power=0.93. For movement time, Tukey post-hoc tests showed that performance at rest was significantly slower than that during exercise at 70%, 100% MPO and supra-maximal effort. Performance at low intensity exercise was significantly slower than that at MPO. For intra-individual variations in reaction time, Tukey tests found that variations under supra-maximal effort and MPO were significantly greater than those at low intensity and 70% MPO.

CONCLUSIONS

It was concluded that exercise facilitates speed of movement when the limbs used for the motor task are not the ones that are being exercised. Reaction time during maximal and supra-maximal exercise demonstrates large intra-individual variations.

Performance of a psychomotor skill following rest, exercise at the plasma epinephrine threshold and maximal intensity exercise

The purpose of this study was to examine the effect of exercising at the epinephrine threshold and at Maximum Power Output on the performance of a skill that requires both decision-making and motor performance. Participants (N=12) undertook an incremental test to exhaustion from which their epinephrine threshold and Maximum Power Output were calculated. They were then examined on a soccer skill test following rest and exercise that was previously determined to elicit their epi nephrine threshold and Maximum Power Output. The soccer test examined the participants' speed and accuracy of response. Speed of response was measured by voice reaction time and whole body reaction time. No significant effects of exercise were shown for any of the variables. The need for further research using more complex skill tests and the use of discontinuous exercise protocols, rather than continuous ones, is recommended.

The measurement of plasma catecholamine and lactate thresholds: a comparison of methods

Plasma lactate and catecholamine thresholds were calculated using three different variations of linear regression, an algorithmic linear regression method, a log-log transformation method and a semi-log method. A group of 18 male sports science students undertook an incremental test to exhaustion on a cycle ergometer. A 5-ml blood sample was drawn at rest, after 4 min of exercise and every 2 min thereafter until the cessation of the test. Lactate, adrenaline and noradrenaline concentrations were measured. Lactate threshold (Th1a), adrenaline threshold (ThA) and noradrenaline threshold (ThNA) were calculated using each of the three methods. The best fits of the methods were examined by comparing their standard error of estimates (SEEs). The algorithmic method demonstrated a higher SEE than the other two methods, but only for Th1a and ThNA. The power output for which each method calculated the thresholds demonstrated a main effect for method. Tukey post hoc tests showed that the algorithmic method produced significantly higher outputs than the other two methods, which did not differ significantly from one another. Comparison of these power outputs showed that Th1a and ThA differed significantly, regardless of method, there were no other significant differences. Plasma concentrations of lactate, adrenaline and noradrenaline showed that the values of Th1a and ThNA calculated by the algorithmic method were significantly higher than those calculated using the other two methods, which did not differ significantly from one another. The only significant difference for ThA was between the algorithmic and semi-log methods. Correlations between the power outputs at which each method calculated the thresholds varied greatly between methods, and were at best only moderate (r = 0.63). It was concluded that the algorithmic method was less powerful than the other two methods, and that Th1a, ThA and ThNA are not highly correlated.

Exercise, plasma catecholamine concentrations and decision-making performance of soccer players on a soccer-specific test

The main aim of this study was to compare the decision-making performance of college soccer players on a soccer-specific, tachistoscopically presented test, at rest and while exercising at their adrenaline threshold and at their maximum power output. These were determined following an incremental test to exhaustion on a cycle ergometer. After the initial maximum power test, participants (n = 9) were allowed 10 habituation trials on the soccer decision-making test. Participants' decision-making performance was tested at rest, while cycling at a power output that had previously been determined to elicit their adrenaline threshold and while cycling at maximum power output. Accuracy and speed of decision were the dependent variables. A one-way repeated-measures analysis of variance showed no significant effect of exercise on accuracy, and showed speed of decision to be significantly affected by exercise. Tukey post-hoc tests showed that speed of decision at rest was significantly slower than in the other two conditions, which did not differ significantly from one another. Based on allocatable resources theories of arousal and performance, we conclude that the adrenaline threshold may be indicative of increases in the resources available to the individual. Furthermore, we considered that exercise at maximum power output may only induce a moderate rather than a high level of arousal.

The effect of exercise on cognitive performance in soccer-specific tests

Two experiments were carried out to examine the effect of moderate and maximal exercise on the cognitive performance of experienced soccer players. Experiment 1 examined the speed and visual search in familiar (game) and unfamiliar (non-game) contexts. Participants had to detect, as quickly as possible, the presence or absence of a ball in tachistoscopically presented slides. Participants were tested at rest and while exercising at 70 and 100% maximum power output. A main effect of exercise intensity was demonstrated and Tukey post-hoc tests showed that performance during maximal exercise was significantly better than in the other two conditions. We concluded that exercise significantly improves speed of visual search. Experiment 2 examined the effects of exercise on speed of search, speed of decision following ball detection, overall speed of decision and accuracy of decision at rest and while exercising at 70 and 100% maximum power output. A repeated-measures multivariate analysis of variance and Tukey post-hoc tests showed that performance during exercise was significantly better than at rest. Observation of the separate univariate analyses of variance demonstrated that most of the variance could be accounted for by overall speed of decision and speed of decision after ball detection. We concluded that exercise induces not only an improvement in a simple task, like speed of visual search, but also an overall increase in speed of information processing. Theories concerning the effect of emotionally induced arousal on cognitive performance do not accurately predict the effect of physically induced arousal on cognitive tasks.

Performance of soccer players on tests of field dependence/independence and soccer-specific decision-making tests

The purpose of this study was to examine the relationship of the performance of male amateur soccer players on tests of field dependence/independence and soccer-specific decision-making tests. The relationships between the participants' (N = 14) accuracy, and speed of decision, on simple and complex soccer decision-making tests; scores on Parts B or C of the Group Embedded Figures Test under normal conditions: scores on Parts B or C of the Group Embedded Figures Test when timed; and time taken to complete the timed condition of the Group Embedded Figures Test were examined. There were no significant correlations between performance on the soccer specific tests and the tests of field dependence/independence.

Phytol metabolites are circulating dietary factors that activate the nuclear receptor RXR

RXR is a nuclear receptor that plays a central role in cell signaling by pairing with a host of other receptors. Previously, 9-cis-retinoic acid (9cRA) was defined as a potent RXR activator. Here we describe a unique RXR effector identified from organic extracts of bovine serum by following RXR-dependent transcriptional activity. Structural analyses of material in active fractions pointed to the saturated diterpenoid phytanic acid, which induced RXR-dependent transcription at concentrations between 4 and 64 microM. Although 200 times more potent than phytanic acid, 9cRA was undetectable in equivalent amounts of extract and cannot be present at a concentration that could account for the activity. Phytanic acid, another phytol metabolite, was synthesized and stimulated RXR with a potency and efficacy similar to phytanic acid. These metabolites specifically displaced [3H]-9cRA from RXR with Ki values of 4 microM, indicating that their transcriptional effects are mediated by direct receptor interactions. Phytol metabolites are compelling candidates for physiological effectors, because their RXR binding affinities and activation potencies match their micromolar circulating concentrations. Given their exclusive dietary origin, these chlorophyll metabolites may represent essential nutrients that coordinate cellular metabolism through RXR-dependent signaling pathways.

Identification of a nuclear receptor that is activated by farnesol metabolites

Nuclear hormone receptors comprise a superfamily of ligand-modulated transcription factors that mediate the transcriptional activities of steroids, retinoids, and thyroid hormones. A growing number of related proteins have been identified that possess the structural features of hormone receptors, but that lack known ligands. Known as orphan receptors, these proteins represent targets for novel signaling molecules. We have isolated a mammalian orphan receptor that forms a heterodimeric complex with the retinoid X receptor. A screen of candidate ligands identified farnesol and related metabolites as effective activators of this complex. Farnesol metabolites are generated intracellularly and are required for the synthesis of cholesterol, bile acids, steroids, retinoids, and farnesylated proteins. Intermediary metabolites have been recognized as transcriptional regulators in bacteria and yeast. Our results now suggest that metabolite-controlled intracellular signaling systems are utilized by higher organisms.

Identification of a nuclear receptor that is activated by farnesol metabolites

Nuclear hormone receptors comprise a superfamily of ligand-modulated transcription factors that mediate the transcriptional activities of steroids, retinoids, and thyroid hormones. A growing number of related proteins have been identified that possess the structural features of hormone receptors, but that lack known ligands. Known as orphan receptors, these proteins represent targets for novel signaling molecules. We have isolated a mammalian orphan receptor that forms a heterodimeric complex with the retinoid X receptor. A screen of candidate ligands identified farnesol and related metabolites as effective activators of this complex. Farnesol metabolites are generated intracellularly and are required for the synthesis of cholesterol, bile acids, steroids, retinoids, and farnesylated proteins. Intermediary metabolites have been recognized as transcriptional regulators in bacteria and yeast. Our results now suggest that metabolite-controlled intracellular signaling systems are utilized by higher organisms.

Effect of exercise on simple reaction times of recreational athletes

To examine the effect of moderate and fatiguing exercise on the simple reaction times of recreational athletes, 12 subjects took a simple reaction-time test while at rest and while cycling on a Monark cycle ergometer at 70% and 100% of maximum workload. To estimate 70% and 100% of maximum workload the subjects underwent a standard incremental test until exhaustion, defined as subjects being unable to maintain the required pedal rate of 70 rpm. Simple reaction time during maximal exercise was significantly slower than in the other two conditions which did not differ significantly from one another. Heart rate and rate of perceived exertion differed significantly for all three conditions.

Scores on field independence and performance in snooker

The purpose of this study was to compare the scores on the Group Embedded Figures Test, a measure of field dependence, for 25 male intermediate-level snooker players with scores of 25 intermediate-level sportsmen engaged in soccer, rugby, field hockey, and tennis and to examine the relation between scores on field dependence and performance on a snooker decision-making test. All the snooker players also took a test of decision making in snooker. The snooker players scored significantly more field independent than the sports-science majors on the Group Embedded Figures Test. A Pearson correlation of 0.78 was obtained between scores on the Group Embedded Figures Test and the decision-making test. As there may be an association between scores on field dependence and decision making in snooker, further research should examine sports like lawn bowls and pool where decisions are made in a static environment.