Lizelle Fletcher

Autonomic impairment in rheumatoid arthritis

To determine if there is a difference between autonomic cardiac control as measured by heart rate variability (HRV) in women with rheumatoid arthritis (RA) compared to a healthy control group.

Validation Of Delayed Gadolinium-Enhanced Magnetic Resonance Imaging Of Cartilage And T2 Mapping For Quantifying Distal Metacarpus/Metatarsus Cartilage Thickness In Thoroughbred Racehorses

The purpose of this study was to determine whether delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping are accurate techniques for measuring cartilage thickness in the metacarpus3/metatarsus3 (Mc3/Mt3) of Thoroughbred racehorses. Twenty-four Mc3/Mt3 cadaver specimens were acquired from six healthy racehorses. Cartilage thickness was measured from postintra-articular Gd-DTPA(2-) images acquired using short tau inversion recovery (STIR), and proton density weighted (PDw) sequences, and compared with cartilage thickness measured from corresponding histologic images. Two observers performed each histologic measurement twice at three different sites, with measurement times spaced at least 5 days apart. Histologic cartilage thickness was measured at each of the three sites from the articular surface to the bone-cartilage interface, and from the articular surface to the mineralized cartilage interface (tidemark). Intra-observer repeatability was good to moderate for dGEMRIC where Mc3/Mt3 cartilage was not in contact with the proximal phalanx. Where the Mc3/Mt3 cartilage was in contact with the proximal phalanx cartilage, dGEMRIC STIR and T2 mapping PDw cartilage thicknesses of Mc3/Mt3 could not be measured reliably. When measured from the articular surface to the bone-cartilage interface, histologic cartilage thickness did not differ from STIR or PDw cartilage thickness at the site where the Mc3/Mt3 cartilage surface was separated from the proximal phalanx cartilage (P > 0.05). Findings indicated that dGEMRIC STIR and T2 mapping PDw are accurate techniques for measuring Mc3/Mt3 cartilage thickness at locations where the cartilage is not in direct contact with the proximal phalanx cartilage.

Dissociative Mental States Are Canonically Associated with Decreased Temporal Theta Activity on Spectral Analysis of EEG

Quantitative electroencephalographic (QEEG) changes relating to dissociative experiences have only rarely been demonstrated, and dissociative states were not quantified in those studies. The aim of this study was to explore concurrent associations between quantified dissociative states and QEEG spectral parameters, in particular theta activity, in psychiatric patients. Fifty psychiatric patients completed the State Scale of Dissociation (SSD) immediately after a 15-min EEG recording. The EEG was assessed by conventional clinical visual analysis as well as by quantitative (QEEG) spectral analysis. Canonical analysis was performed between the set of SSD subscale scores and the following QEEG parameters: alpha–theta magnitude ratios, and relative as well as absolute theta magnitude obtained from right and left mid- to posterior-temporal and parieto-occipital derivations. The SSD transferred well to the present data in terms of reliability and internal criterion-related validity. The SSD and Dissociative Experiences Scale (DES) correlated significantly (r = .73, p < .001). Conventional EEG analysis identified 29 EEGs (58%) as abnormal. The main abnormality in 23 EEGs was slowing, maximal temporally in half of these cases. Canonical analyses confirmed a statistically significant relationship between the dissociation variables (especially conversion and depersonalization symptoms) and the QEEG variables (especially relative theta magnitude in the temporal regions; R = .72, p = .03, for SSD–QEEG; and R = .66, p = .04, for DES–QEEG). Quantified dissociative mental states are positively canonically associated with decreased temporal theta activity and increased alpha–theta ratios on QEEG in psychiatric patients with a high tendency to dissociate. The potential implications of the dissociation–theta–alpha relationship for understanding normal attentional processes need to be studied further.

A comparison between heart rate and heart rate variability as indicators of cardiac health and fitness

Quantification of cardiac autonomic activity and control via heart rate (HR) and heart rate variability (HRV) is known to provide prognostic information in clinical populations. Issues with regard to standardization and interpretation of HRV data make the use of the more easily accessible HR on its own as an indicator of autonomic cardiac control very appealing. The aim of this study was to investigate the strength of associations between an important cardio vascular health metric such as VO2max and the following: HR, HRV indicators, and HR normalized HRV indicators. A cross sectional descriptive study was done including 145 healthy volunteers aged between 18 and 22 years. HRV was quantified by time domain, frequency domain and Poincaré plot analysis. Indirect VO2max was determined using the Multistage Coopers test. The Pearson correlation coefficient was calculated to quantify the strength of the associations. Both simple linear and multiple stepwise regressions were performed to be able to discriminate between the role of the individual indicators as well as their combined association with VO2max. Only HR, RR interval, and pNN50 showed significant (p < 0.01, p < 0.01, and p = 0.03) correlations with VO2max. Stepwise multiple regression indicated that, when combining all HRV indicators the most important predictor of cardio vascular fitness as represented by VO2max, is HR. HR explains 17% of the variation, while the inclusion of HF (high frequency HRV indicator) added only an additional 3.1% to the coefficient of determination. Results also showed when testing the normalized indicators, HR explained of the largest percentage of the changes in VO2max (16.5%). Thus, HR on its own is the most important predictor of changes in an important cardiac health metric such as VO2max. These results may indicate that during investigation of exercise ability (VO2max) phenomena, quantification of HRV may not add significant value.

Predicting a dissociative disorder from type of childhood maltreatment and abuser-abused relational tie

ABSTRACT We investigate the types of childhood maltreatment and abuser–abused relational ties that best predict a dissociative disorder (DD). Psychiatric inpatients (n = 116; mean age = 35; F:M = 1.28:1) completed measures of dissociation and trauma. Abuse type and abuser–abused relational ties were recorded in the Traumatic Experiences Questionnaire. Multidisciplinary team clinical diagnosis or administration of the SCID-D-R to high dissociators confirmed DD diagnoses. Logit models described the relationships between abuser–abused relational tie and the diagnostic grouping of patients, DD present (n = 16) or DD absent (n = 100). Fisher’s exact tests measured the relative contribution of specific abuse types. There was a positive relationship between abuse frequency and the presence of DD. DD patients experienced more abuse than patients without DDs. Two combinations of abuse type and relational tie predicted a DD: childhood emotional neglect by biological parents/siblings and later emotional abuse by intimate partners. These findings support the early childhood etiology of DDs and subsequent maladaptive cycles of adult abuse. Enquiries about childhood maltreatment should include a history of emotional neglect by biological parents/siblings. Adult emotional abuse by intimate partners should assist in screening for DDs.

Feasibility for mapping cartilage t1 relaxation times in the distal metacarpus3/metatarsus3 of thoroughbred racehorses using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dgemric): normal cadaver study

Osteoarthritis of the metacarpo/metatarsophalangeal joints is one of the major causes of poor performance in horses. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) may be a useful technique for noninvasively quantifying articular cartilage damage in horses. The purpose of this study was to describe dGEMRIC characteristics of the distal metacarpus3/metatarsus3 (Mc3/Mt3) articular cartilage in 20 cadaver specimens collected from normal Thoroughbred horses. For each specimen, T1 relaxation time was measured from scans acquired precontrast and at 30, 60, 120, and 180 min post intraarticular injection of Gd-DTPA(2-) (dGEMRIC series). For each scan, T1 relaxation times were calculated using five regions of interest (sites 1-5) in the cartilage. For all sites, a significant decrease in T1 relaxation times occurred between precontrast scans and 30, 60, 120, and 180 min scans of the dGEMRIC series (P < 0.0001). A significant increase in T1 relaxation times occurred between 60 and 180 min and between 120 and 180 min post Gd injection for all sites. For sites 1-4, a significant increase in T1 relaxation time occurred between 30 and 180 min postinjection (P < 0.05). Sites 1-5 differed significantly among one another for all times (P < 0.0001). Findings from this cadaver study indicated that dGEMRIC using intraarticular Gd-DTPA(2-) is a feasible technique for measuring and mapping changes in T1 relaxation times in equine metacarpo/metatarsophalangeal joint cartilage. Optimal times for postcontrast scans were 60-120 min. Future studies are needed to determine whether these findings are reproducible in live horses.

Health-promoting behaviors in South African music students: A replication study

The study evaluated self-reported health-promoting behaviors and psychosocial well-being of undergraduate music students (n = 144) and was designed as an attempt to replicate and extend previous studies. The goals were (a) to differentiate those behaviors in undergraduate music students, and (b) to examine the influences of gender and instrument played. Participants completed the health-promoting lifestyle inventory (HPLP-II), the self-efficacy (SES) and the self-regulation (SRS), scales, as well as the positive and negative affect (PANAS) scale. Results show overall deficiencies in music students’ healthy habits, which is in line with previous studies. Generally, low values were found for health responsibility, physical activity, stress management and nutrition. Female students, however, achieved significantly better results for nutrition choices. Keyboard players were found to be the weakest group in health-promoting behaviors. Significant correlations were found between the subscales of the HPLP-II, self-efficacy (SES), self-regulation (SRS) and emotional state (PANAS). These results similar to other studies, moreover, support the assumption that music students’ healthy behaviors generalize across different socio-cultural contexts.

From study to work: methodological challenges of a graduate destination survey in the Western Cape, South Africa

Current literature proposes several strategies for improving response rates to student evaluation surveys. Graduate destination surveys pose the difficulty of tracing graduates years later when their contact details may have changed. This article discusses the methodology of one such a survey to maximise response rates. Compiling a sample frame with reliable contact details was most important, but may require using additional sources of information other than university records. In hindsight, graduates should have been contacted prior to the survey to introduce it and stress its importance, while email and postal reminders appeared to have a limited effect on non-respondents. Due to varying response rates between participating universities, online responses were augmented with a call centre administering the survey telephonically to non-respondents. Although overall differences between online and telephonic responses appeared to be small, certain question items may need to be treated with caution when conducting telephonic surveys.

Heart Rate Variability in Healthy, Adult Pony Mares During Transrectal Palpation of the Reproductive Tract by Veterinary Students

Abstract Few studies exist on evaluating stress in animals used for veterinary student training. The aim of this study was to (1) assess the stress response of habituated mares during student transrectal palpations of the reproductive tract; (2) determine the recovery period; and (3) evaluate the effect of the mares’ experience and age on the stress response. Heart rate variability (HRV) was employed to quantify stress by measuring the influence of the autonomic nervous system on the heart. RR intervals from 21 mares were recorded, and 5‐minute tachograms from the following time points were analyzed: prepalpation (on pasture and in stocks), during palpation (first and last 5 minutes of the 20‐minute palpation period), and postpalpation (5, 35, and 65 minutes). The heart rate and HRV obtained were compared by one‐way repeated measures analysis of variance to the baseline measurements (pasture and stock). The most significant shifts toward the sympathetic component were recorded during the first 5 minutes of palpation and 65 minutes postpalpation. Coactivation of the parasympathetic and sympathetic branches was recorded during the initial stage of palpation. This may be attributed to recognition (prediction of outcome) of the procedure by the mare. The age and experience of the habituated horses did not influence the HRV indicators. The 20‐minute palpation period was tolerated by mares accustomed to palpation, but the related stress response after prolonged restricted movement in the stocks was pronounced. Thus, horses should be promptly released from stocks after similar veterinary procedures to minimize distress. HighlightsHabituated mares showed coactivation of the parasympathetic and sympathetic nervous system in first 5 minutes of palpation.The first 5 minutes of palpation reflected a significant sympathetic dominance.Movement restriction in a stock over 130 minutes resulted in a sympathetic response.Age and experience did not influence the stress response of habituated mares.

The Difference Between Exercise-Induced Autonomic and Fitness Changes Measured After 12 and 20 Weeks of Medium-to-High Intensity Military Training.

Abstract Grant, CC, Mongwe, L, Janse van Rensburg, DC, Fletcher, L, Wood, PS, Terblanche, E, and du Toit, PJ. The difference between exercise-induced autonomic and fitness changes measured after 12 and 20 weeks of medium-to-high intensity military training. J Strength Cond Res 30(9): 2453–2459, 2016—The aim of this study was to compare the physical fitness, based on VO2max and exercise-induced cardiac autonomic changes, measured by heart rate variability (HRV) of 12 weeks with 20 weeks of training in the South African National Defence Force. Recruits (n = 154) participated in a medium-to-high intensity exercise intervention (daily energy expenditure: 8,485 kJ·d−1). The significant effect on VO2max between weeks 1 and 12 (48.57, SD = 9.25 vs. 53.36, SD = 7.21] did not continue during weeks 12–20 (53.36, SD = 7.21 vs. 53.87, SD = 7.87). No changes in the supine low frequency (LF)/high frequency (HF) (0.48, SD = 0.51 vs. 0.41, SD = 0.64) or the standing LF/HF (4.02, SD = 5.14 vs. 3.91, SD = 5.28), an indicator of autonomic balance and a possible indicator of overtraining syndrome, suggests that overtraining did not take place during weeks 12–20. This was confirmed with further decreases in supine and standing heart rate. However, the power of the vagal-induced variability continued to increase after 12 weeks. Increased vagal influence without concurrent change in autonomic balance may be interpreted as decreased sympathetic cardiac control. It is important to note that although no fitness changes were detected, positive cardiac autonomic conditioning did continue between weeks 12 and 20, as measured by increased vagal-induced HRV and decreased sympathetic influence on cardiac control. Results may be extrapolated to training in the normal population/athletes after a medium-to-high intensity exercise program, as this intervention was a closely monitored and standardized exercise program.