The Fatigue and Altered Cognition Scale among SARS-CoV-2 Survivors: Psychometric Properties and Item Correlations with Depression and Anxiety Symptoms

Background/Objectives: This study examined the psychometric properties of the Fatigue and Altered Cognition Scale (FACs) among adult COVID-19 survivors and its unique ability to assess symptomology not accounted for by measures of depression and anxiety. Methods: COVID-19 survivors completed an online survey that included the FACs, a measure of brain fog and central fatigue with 20 items rated on a digital-analog scale. Useable data from 559 participants were analyzed to test the two-factor structure of the FACs, test for measurement invariance by sex and device was used to complete the survey (hand-held, computer), and item correlations with symptoms of depression and anxiety were examined. Results: The two-factor structure of the FACs replicated, supporting the separate assessments of brain fog and fatigue, χ2(164) = 1028.363, p < 0.001, CFI = 0.934, TLI = 0.923, RMSEA = 0.097, SRMR = 0.053. The FACs exhibited invariance at the scalar level, indicating item and factor integrity regardless of sex and device type. Using a correlation > 0.70 as a criterion (i.e., indicating more than 50% shared variance between two items), items on the FACs (assessing fatigue and lack of energy) were highly correlated with feeling tired or having little energy on the depression measure. No other items correlated with any anxiety symptom larger than 0.70. Conclusions: The FACs appears to be a psychometrically sound and efficient measure for use with COVID-19 survivors, assessing symptoms of brain fog and central fatigue that are not attributable to symptoms assessed by established measures of depression and anxiety.

The Fracture Risk of Elderly Patients With Atopic Dermatitis

Background: A higher fracture risk has been reported previously in patients with atopic dermatitis (AD). The bone mineral density (BMD) was not accounted for in these studies. Objective: To investigate the fracture risk in AD patients after adjustment for factors including BMD. Methods: We retrospectively analyzed AD patients (≥45 years) who underwent BMD examination at our hospital from July 2010 to February 2023. Individuals who received BMD examinations during a health checkup were identified as the controls. We documented their clinical characteristics, BMD, 10-year risk for a major fracture based on FRAX (Fracture Risk Assessment Tool), and development of osteoporotic fractures. Patients were followed until development of new onset fracture or the end of the study period. A cross-sectional comparison of BMD between AD patients and controls at baseline was performed using the Mann-Whitney U test after propensity score matching (PSM). Their fracture risks were compared using the multivariate Cox regression model. BMD and fracture risk were also compared between AD patients who received systemic therapy and those who did not. Results: A total of 50 AD patients and 386 controls were enrolled. The median age was older in AD patients when compared with controls (70 years vs 60 years). Their BMD at all sites was similar after PSM. After a median follow-up of 1.7-2.0 years, 13 osteoporotic fractures were identified. In the multivariate Cox regression analysis, AD was not associated with new onset fractures of all sites (adjusted hazard ratio [aHR] 2.55, 95% confidence interval [CI] 0.72-9.01) but was significantly associated with new onset vertebral fractures (aHR 6.80, 95% CI 1.77-26.17). The BMD and incidence of fractures were similar between AD who received systemic therapy and those who did not. Conclusions: Elderly AD patients had similar BMD but a higher short-term risk for vertebral fractures when compared with the controls.

Efficient assessment of brain fog and fatigue: Development of the Fatigue and Altered Cognition Scale (FACs)

Debilitating symptoms of fatigue and accompanying "brain fog" are observed among patients with various chronic health conditions. Unfortunately, an efficient and psychometrically sound instrument to assess these co-occurring symptoms is unavailable. Here, we report the development and initial psychometric properties of the Fatigue and Altered Cognition Scale (the FACs), a measure of self-reported central fatigue and brain fog. Traumatic brain injury (TBI) was chosen to model and develop the FACs due to research team expertise and established links between TBI and the symptom complex. Potential items were generated by researchers and clinicians with experience treating these symptoms, drawing from relevant literature and review of patient responses to measures from past and current TBI studies. The 20 candidate items for the FACs-ten each to assess altered cognition (i.e., brain fog) and central fatigue-were formatted on an electronic visual analogue response scale (eVAS) via an online survey. Demographic information and history of TBI were obtained. A total of 519 participants consented and provided usable data (average age = 40.23 years; 73% female), 204 of whom self-reported a history of TBI (75% reported mild TBI). Internal consistency and reliability values were calculated. Confirmatory factor analysis (CFA) examined the presumed two-factor structure of the FACs and a one-factor solution for comparison. A measurement invariance test of the two latent constructs (altered cognition, fatigue) among participants with and without TBI was conducted. All items demonstrated normal distribution. Cronbach's alpha coefficients indicated good internal consistency for both factors (α's = .95). Omega reliability values were favorable (α's = .95). CFA supported the presumed two-factor model and item loadings which outperformed the one-factor model. Measurement invariance found the two-factor structure was consistent between the two groups. Implications of these findings, study limitations, and potential use of the FACs in clinical research and practice are discussed.

The physiological, perceptual, and thermoregulatory responses to facemask use during exercise

The use of masks in public settings and when around people has been recommended to limit the spread of Coronavirus disease 2019 (COVID-19) by major public health agencies. Several different types of masks classified as either medical- or non-medical grade are commonly used among the public. However, concerns with difficulty breathing, re-breathing exhaled carbon dioxide, a decrease in arterial oxygen saturation, and a decrease in exercise performance have been raised regarding the use of mask during exercise. We review the current knowledge related to the effect of different masks during exercise on cardiorespiratory, metabolic, thermoregulatory, and perceptual responses. As such, the current literature seems to suggest that there are minimal changes to cardiovascular, metabolic, and no changes to thermoregulatory parameters with facemask use. However, differences in ventilatory parameters have been reported with submaximal and maximal intensity exercise to volitional fatigue. Literature on perceptual responses to exercise indicate an impact on ratings of perceived exertion, dyspnea, and overall discomfort dependent on mask use as well as exercise intensity. In conclusion, data from the current literature suggests a minimal impact on physiological, perceptual, and thermoregulatory responses dependent on the type of mask used during exercise.

The relationship between outdoor air pollutants and atopic dermatitis of adults: A systematic review and meta-analysis

BACKGROUND

Atopic dermatitis (AD) poses a significant disease burden in adults. Environmental factors are essential in its pathogenesis.

OBJECTIVE

Given the possible role of air pollutants in allergic diseases, it is worthwhile to summarize the effects of outdoor air pollution on adult AD.

METHODS

We undertook a systematic review based on PubMed and EMBASE as of August 16, 2021, and found 20 relevant studies. A random-effects meta-analysis was carried out.

RESULTS

Regarding long-term effects (within months to years), traffic-related air pollution and particulate matter < 2.5 μm in diameter (PM2.5, per 10 μg/m³ increment) are associated with the prevalence of adult AD (OR 1.40, 95%CI [1.24, 1.58] and 1.67, 95%CI [1.26, 2.21]). Exposures to PM2.5 and nitrogen dioxide are associated with incident AD, with ORs of 2.30 (95%CI: 1.25, 4.25) and 1.30 (95%CI: 1.04, 1.61) per 10 μg/m³ increment. In terms of short term effects (within days), exposure to particulate matter < 10 μm in diameter (PM10) and sulfur dioxide (SO₂) are associated with exacerbations of AD at lag day 0 based on those time-series studies, with an excessive risk of 2.9%, in particular, per 10 μg/m³ increment in SO₂ exposure. In addition, both short-term and long-term exposures to these air pollutants are associated with AD symptoms (eczema, pruritus, and sleep disturbance).

CONCLUSIONS

Outdoor air pollutants exert both short-term and long-term adverse effects on adult AD, contributing to its development, severity and exacerbation of symptoms. The influence of air pollution should be considered in the management of adult AD.

Two-stage path analysis with definition variables: An alternative framework to account for measurement error

When estimating path coefficients among psychological constructs measured with error, structural equation modeling (SEM), which simultaneously estimates the measurement and structural parameters, is generally regarded as the gold standard. In practice, however, researchers usually first compute composite scores or factor scores, and use those as observed variables in a path analysis, for purposes of simplifying the model or avoiding model convergence issues. Whereas recent approaches, such as reliability adjustment methods and factor score regression, has been proposed to mitigate the bias induced by ignoring measurement error in composite/factor scores with continuous indicators, those approaches are not yet applicable to models with categorical indicators. In this article, we introduce the two-stage path analysis (2S-PA) with definition variables as a general framework for path modeling to handle categorical indicators, in which estimation of factor scores and path coefficients are separated. It thus allows for different estimation methods in the measurement and the structural path models and easier diagnoses of violations of model assumptions. We conducted three simulation studies, ranging from latent regression to mediation analysis with categorical indicators, and showed that 2S-PA generally produced similar estimates to those using SEM in large samples, but gave better convergence rates, less standard error bias, and better control of Type I error rates in small samples. We illustrate 2S-PA using data from a national data set, and show how researchers can implement it in Mplus and OpenMx. Possible extensions and future directions of 2S-PA are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Teacher's Corner: An R Shiny App for Sensitivity Analysis for Latent Growth Curve Mediation

Mechanisms of behavior change are the processes through which interventions are hypothesized to cause changes in outcomes. Latent growth curve mediation models (LGCMM) are recommended for investigating the mechanisms of behavior change because LGCMM models establish temporal precedence of change from the mediator to the outcome variable. The Correlated Augmented Mediation Sensitivity Analyses (CAMSA) App implements sensitivity analysis for LGCMM models to evaluate if a mediating path (mechanism) is robust to potential confounding variables. The CAMSA approach is described and applied to simulated data, and data from a research study exploring a mechanism of change in the treatment of substance use disorder.

Predictive model specific to young adults for estimating thoracic gas volume for air-displacement plethysmography

BACKGROUND

Thoracic gas volume either measured (mTGV) or predicted by the BodPod® (bpTGV) is used during air-displacement plethysmography to obtain a better estimate of percent body fat. Evidence suggests that bpTGV underestimates mTGV for young adults and this is especially evident for young males.

AIMS

We developed, validated, and cross-validated a TGV prediction model (pTGV) for males and females 18-30 years of age to address this underestimation.

MATERIALS & METHODS

Participants (N = 181; 18-30 years) that had their body composition assessed with the BodPod® were retrospectively randomly assigned to one of two independent subgroups, a validation (n = 145) or cross-validation (n = 36) sample. Ten iterations of the k-fold validation procedure were performed to assess the internal replicability of pTGV within the validation sample. External replicability of pTGV was evaluated by assessing the difference and standard error of the estimate (SEE) compared to mTGV in the cross-validation group.

RESULTS

The model using height, sex and body mass yielded the highest adjusted R² (0.627) and the lowest SEE (0.56 L): pTGV = 0.615338 × Sex (0 = Female, 1 = Male) + 0.056267 × Height (cm) - 0.011006 × Body Mass (kg) - 5.358839. R² remained stable across 10 iterations of the k-fold procedure (average R²  = 0.64). Differences between pTGV and mTGV were not significantly different than zero for the total cross-validation sample (-0.06 ± 0.7 L; SEE = 3.0%), for males (-0.11 ± 0.7 L; SEE = 3.7%), or for females (-0.02 ± 0.7 L; SEE = 5.3%).

CONCLUSION

We recommend that when it is impractical to obtain mTGV, the strong internal and external replicability of the new prediction model supports its use for males and females ages 18-30 years old during air-displacement plethysmography.

Hierarchy and Reliability of the Preschool Language Scales-Fifth Edition: Mokken Scale Analysis

Purpose This study examined the psychometric properties of the Preschool Language Scales-Fifth Edition (PLS-5 English) among preschool children from low-socioeconomic status (SES) families. Method The PLS-5 was administered individually to 169 3- to 4-year-old children enrolled in Head Start programs. We carried out a Mokken scale analysis (MSA), which is a nonparametric item response theory analysis, to examine the hierarchy among items and the reliability of test scores of the PLS-5 Auditory Comprehension (AC) and Expressive Communication (EC) scales. Results The PLS-5 EC items retained a moderate Mokken scale with the inclusion of all the items. On the other hand, the PLS-5 AC items formed a moderate Mokken scale only with the exclusion of five unscalable items. The latent class reliability coefficients for the AC and the EC scale scores were both above .90. Several items that violated the invariant item ordering assumption were found for both scales. Conclusions MSA can be used to examine the relationship between the latent language ability and the probability of passing an item with ordinal responses. Results indicate that for preschool children from low-SES families, it is appropriate to use the PLS-5 EC scale scores for comparing individuals' expressive language abilities; however, researchers and speech-language pathologists should be cautious when using the PLS-5 AC scale scores to evaluate individuals' receptive language abilities. Other implications of the MSA results are further discussed.

Latent Class Mediation: A Comparison of Six Approaches

Latent class mediation modeling is designed to estimate the mediation effect when both the mediator and the outcome are latent class variables. We suggest using an adjusted one-step approach in which the latent class models for the mediator and the outcome are estimated first to decide on the number of classes, then the latent class models and the mediation model are jointly estimated. We present both an empirical demonstration and a simulation study to compare the performance of this one-step approach to a standard three-step approach with modal assignment (modal) and four different modern three-step approaches. Results from the study indicate that unadjusted modal, which ignores the classification errors of the latent class models, produced biased mediation effects. On the other hand, the adjusted one-step approach and the modern three-step approaches performed well with respect to bias for estimating mediation effects, regardless of measurement quality (i.e., model entropy) and latent class size. Among the three-step approaches we investigated, the maximum likelihood method with modal assignment and the BCH correction with robust standard error estimators are good alternatives to the adjusted one-step approach, given their unbiased standard error estimations.

The Differential Importance of Component Skills on Reading Comprehension Test Performance Among Struggling Adolescent Readers

Reading comprehension tests vary in format and characteristics, which may influence the extent to which component skills are involved in test performance. With students in Grades 6 to 8 with reading difficulties, dominance analyses examined the differential importance of component reading and language skills (word- and text-reading fluency, vocabulary, listening comprehension, and working memory) on several standardized tests of reading comprehension: The Gates-MacGinitie Reading Test, 4th edition (GMRT), Group Reading Assessment and Diagnostic Evaluation, Gray Oral Reading Test, 5th edition (GORT-5), and the Test of Silent Reading Efficiency and Comprehension (TOSREC). Students' word- and text-reading fluency skills were generally the most dominant predictors of performance on most reading comprehension tests, especially those with a time limit (GMRT and TOSREC). Listening comprehension was most important on the GORT-5, a test in which students read passages orally and listen to questions read by an examiner. Working memory was the least important component skill across the reading comprehension tests. Overall, results were consistent with previous work indicating that reading comprehension measures vary with regard to the skills or knowledge sources that are most important for test performance and extend these findings to struggling adolescent readers. Implications for research and practice are discussed.

Applying methods for personalized medicine to the treatment of alcohol use disorder

OBJECTIVE

Numerous behavioral treatments for alcohol use disorder (AUD) are effective, but there are substantial individual differences in treatment response. This study examines the potential use of new methods for personalized medicine to test for individual differences in the effects of cognitive behavioral therapy (CBT) versus motivational enhancement therapy (MET) and to provide predictions of which will work best for individuals with AUD. We highlight both the potential contribution and the limitations of these methods.

METHOD

We performed secondary analyses of abstinence among 1,144 participants with AUD participating in either outpatient or aftercare treatment who were randomized to receive either CBT or MET in Project MATCH. We first obtained predicted individual treatment effects (PITEs), as a function of 19 baseline client characteristics identified a priori by MATCH investigators. Then, we tested for the significance of individual differences and examined the predicted individual differences in abstinence 1 year following treatment. Predictive intervals were estimated for each individual to determine if they were 80% more likely to achieve abstinence in one treatment versus the other.

RESULTS

Results indicated that individual differences in the likelihood of abstinence at 1 year following treatment were significant for those in the outpatient sample, but not for those in the aftercare sample. Individual predictive intervals showed that 37% had a better chance of abstinence with CBT than MET, and 16% had a better chance of abstinence with MET. Obtaining predictions for a new individual is demonstrated.

CONCLUSIONS

Personalized medicine methods, and PITE in particular, have the potential to identify individuals most likely to benefit from one versus another intervention. New personalized medicine methods play an important role in putting together differential effects due to previously identified variables into one prediction designed to be useful to clinicians and clients choosing between treatment options. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Modeling Measurement Errors of the Exogenous Composites From Congeneric Measures in Interaction Models

We investigated the performance of two single indicator methods: latent moderated structural equation (LMS) and reliability-adjusted product indicator (RAPI) methods, on testing interaction effects with congeneric measures, which vary in factor loadings and error variances under a common factor. Additionally, in the simulation study, we compared the performance of four reliability estimates (Cronbach's alpha, omega composite, Coefficient H, and greatest lower bound [GLB]) to adjust for the exogenous composites' measurement errors. Results from the study showed that: while estimating interaction effects with exogenous composites from congeneric measures, the four reliability estimates performed comparably well. Recommendations on the choice of reliability estimates between the LMS and the RAPI methods under different sample sizes and population reliability conditions are further discussed.

Resilience facilitates adjustment through greater psychological flexibility among Iraq/Afghanistan war veterans with and without mild traumatic brain injury

OBJECTIVES

Although many Iraq/Afghanistan warzone veterans report few problems with adjustment, a substantial proportion report debilitating mental health symptoms and functional impairment, suggesting the influence of personal factors that may promote adjustment. A significant minority also incur warzone-related traumatic brain injury (TBI), the majority of which are of mild severity (mTBI). We tested direct and indirect pathways through which a resilient personality prototype predicts adjustment of warzone veterans with and without mTBI over time.

METHOD

A sample of 264 war veterans (181 men) completed measures of lifetime and warzone-related TBIs, personality traits, psychological adjustment, quality of life, and functional impairment. Social support, coping, and psychological flexibility were examined as mediators of the resilience-adjustment relationship. Instruments were administered at baseline, 4-, 8-, and 12-month assessments. Structural equation models accounted for combat exposure and response style.

RESULTS

Compared with a nonresilient personality prototype, a resilient prototype was directly associated with lower PTSD, depression, and functional disability, and higher quality of life at all time-points. Warzone mTBIs frequency was associated with higher scores on a measure of functional disability. Indirect effects via psychological flexibility were observed from personality to all outcomes, and from warzone-related mTBIs to PTSD, depression, and functional disability, at each time-point.

CONCLUSIONS

Several characteristics differentiate veterans who are resilient from those who are less so. These findings reveal several factors through which a resilient personality prototype and the number of mTBIs may be associated with veteran adjustment. Psychological flexibility appears to be a critical modifiable factor in veteran adjustment. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The (Lack of) Replication of Self-Reported Mindfulness as a Mechanism of Change in Mindfulness-Based Relapse Prevention for Substance Use Disorders

The development and evaluation of mindfulness-based interventions for a variety of psychological and medical disorders has grown exponentially over the past 20 years. Yet, calls for increasing the rigor of mindfulness research and recognition of the difficulties of conducting research on the topic of mindfulness have also increased. One of the major difficulties is the measurement of mindfulness, with varying definitions across studies and ambiguity with respect to the meaning of mindfulness. There is also concern about the reproducibility of findings given few attempts at replication. The current secondary analysis addressed the issue of reproducibility and robustness of the construct of self-reported mindfulness across two separate randomized clinical trials of mindfulness-based relapse prevention (MBRP), as an aftercare treatment for substance use disorder. Specifically, we tested the robustness of our previously published findings, which identified a latent construct of mindfulness as a significant mediator of the effect of MBRP on reducing craving following treatment. First, we attempted to replicate the findings in a separate randomized clinical trial of MBRP. Second, we conducted sensitivity analyses to test the assumption of the no-omitted confounder bias in a mediation model. The effect of MBRP on self-reported mindfulness and overall mediation effect failed to replicate in a new sample. The effect of self-reported mindfulness in predicting craving following treatment did replicate and was robust to the no-omitted confounder bias. The results of this work shine a light on the difficulties in the measurement of mindfulness and the importance of examining the robustness of findings.

Sensitivity Analysis of the No-Omitted Confounder Assumption in Latent Growth Curve Mediation Models

Latent growth curve mediation models are increasingly used to assess mechanisms of behavior change. For latent growth mediation model, like any another mediation model, even with random treatment assignment, a critical but untestable assumption for valid and unbiased estimates of the indirect effects is that there should be no omitted variable that confounds indirect effects. One way to address this untestable assumption is to conduct sensitivity analysis to assess whether the inference about an indirect effect would change under varying degrees of confounding bias. We developed a sensitivity analysis technique for a latent growth curve mediation model. We compute the biasing effect of confounding on point and confidence interval estimates of the indirect effects in a structural equation modeling framework. We illustrate sensitivity plots to visualize the effects of confounding on each indirect effect and present an empirical example to illustrate the application of the sensitivity analysis.

The Impact of Partial Measurement Invariance on Testing Moderation for Single and Multi-Level Data

Moderation effect is a commonly used concept in the field of social and behavioral science. Several studies regarding the implication of moderation effects have been done; however, little is known about how partial measurement invariance influences the properties of tests for moderation effects when categorical moderators were used. Additionally, whether the impact is the same across single and multilevel data is still unknown. Hence, the purpose of the present study is twofold: (a) To investigate the performance of the moderation test in single-level studies when measurement invariance does not hold; (b) To examine whether unique features of multilevel data, such as intraclass correlation (ICC) and number of clusters, influence the effect of measurement non-invariance on the performance of tests for moderation. Simulation results indicated that falsely assuming measurement invariance lead to biased estimates, inflated Type I error rates, and more gain or more loss in power (depends on simulation conditions) for the test of moderation effects. Such patterns were more salient as sample size and the number of non-invariant items increase for both single- and multi-level data. With multilevel data, the cluster size seemed to have a larger impact than the number of clusters when falsely assuming measurement invariance in the moderation estimation. ICC was trivially related to the moderation estimates. Overall, when testing moderation effects with categorical moderators, employing a model that accounts for the measurement (non)invariance structure of the predictor and/or the outcome is recommended.

Evaluation of Two Methods for Modeling Measurement Errors When Testing Interaction Effects With Observed Composite Scores

Path models with observed composites based on multiple items (e.g., mean or sum score of the items) are commonly used to test interaction effects. Under this practice, researchers generally assume that the observed composites are measured without errors. In this study, we reviewed and evaluated two alternative methods within the structural equation modeling (SEM) framework, namely, the reliability-adjusted product indicator (RAPI) method and the latent moderated structural equations (LMS) method, which can both flexibly take into account measurement errors. Results showed that both these methods generally produced unbiased estimates of the interaction effects. On the other hand, the path model-without considering measurement errors-led to substantial bias and a low confidence interval coverage rate of nonzero interaction effects. Other findings and implications for future studies are discussed.

Finite population correction for two-level hierarchical linear models

The research literature has paid little attention to the issue of finite population at a higher level in hierarchical linear modeling. In this article, we propose a method to obtain finite-population-adjusted standard errors of Level-1 and Level-2 fixed effects in 2-level hierarchical linear models. When the finite population at Level-2 is incorrectly assumed as being infinite, the standard errors of the fixed effects are overestimated, resulting in lower statistical power and wider confidence intervals. The impact of ignoring finite population correction is illustrated by using both a real data example and a simulation study with a random intercept model and a random slope model. Simulation results indicated that the bias in the unadjusted fixed-effect standard errors was substantial when the Level-2 sample size exceeded 10% of the Level-2 population size; the bias increased with a larger intraclass correlation, a larger number of clusters, and a larger average cluster size. We also found that the proposed adjustment produced unbiased standard errors, particularly when the number of clusters was at least 30 and the average cluster size was at least 10. We encourage researchers to consider the characteristics of the target population for their studies and adjust for finite population when appropriate. (PsycINFO Database Record

Advancing Stage 2 Research on Measures for Monitoring Kindergarten Reading Progress

Although several measures exist for frequently monitoring early reading progress, little research has specifically investigated their technical properties when administered on a frequent basis with kindergarten students. In this study, kindergarten students ( N = 137) of whom the majority was receiving supplemental intervention for reading skills were monitored using Letter Sound Fluency, Phoneme Segmentation Fluency, Word Reading Fluency, Nonsense Word Fluency, Highly Decodable Passages, and Spelling on a biweekly basis between February and May. Acceptable reliability was observed for all measures. Analyses of slope validity using latent growth models, latent change score models, and slope differences according to level of year-end achievement indicated that the relation of slope to overall reading skills varied across the measures. A suggested approach to kindergarten students' reading progress is offered that includes Letter Sound Fluency and a measure of word-reading skills to provide a comprehensive picture of student growth toward important year-end reading outcomes.

Resilience and Traumatic Brain Injury Among Iraq/Afghanistan War Veterans: Differential Patterns of Adjustment and Quality of Life

OBJECTIVE

We examined the degree to which a resilient personality prototype predicted adjustment among war Veterans with and without a traumatic brain injury (TBI) while covarying the level of combat exposure.

METHOD

A total of 127 war Veterans (107 men, 20 women; average age = 37 years) participated. Personality prototypes were derived from the Multidimensional Personality Questionnaire (Patrick, Curtain, & Tellegen, 2002). Measures were administered at baseline, and a subset was administered at 4- and 8-month follow-ups.

RESULTS

Veterans with resilient personalities reported less sleep disturbance, more health-promoting behaviors, psychological flexibility, and emotional distress tolerance than Veterans with undercontrolled or overcontrolled prototypes. Path models revealed that resilience significantly predicted posttraumatic stress disorder (PTSD), depression, quality of life, and social support over time. TBI had unique and consistent effects only on PTSD.

CONCLUSION

Personality characteristics influence distress and quality of life among war Veterans with and without TBI. Implications for assessment, interventions, and research are discussed.

Resilience, traumatic brain injury, depression, and posttraumatic stress among Iraq/Afghanistan war veterans

OBJECTIVE

We examined the prospective influence of the resilient, undercontrolled, and overcontrolled personality prototypes on depression and posttraumatic stress disorder (PTSD) symptoms among Iraq/Afghanistan war veterans. After accounting for the possible influence of combat exposure, we expected that the resilient prototype would predict lower depression and PTSD over time and would be associated with adaptive coping strategies, higher social support, lower psychological inflexibility, and higher self-reported resilience relative to overcontrolled and undercontrolled prototypes, independent of traumatic brain injury (TBI) status.

METHOD

One hundred twenty-seven veterans (107 men, 20 women; average age = 37) participated in the study. Personality was assessed at baseline, and PTSD and depression symptoms were assessed 8 months later. Path analysis was used to test the direct and indirect effects of personality on distress.

RESULTS

No direct effects were observed from personality to distress. The resilient prototype did have significant indirect effects on PTSD and depression through its beneficial effects on social support, coping and psychological inflexibility. TBI also had direct effects on PTSD.

CONCLUSIONS

A resilient personality prototype appears to influence veteran adjustment through its positive associations with greater social support and psychological flexibility, and lower use of avoidant coping. Low social support, avoidant coping, and psychological inflexibility are related to overcontrolled and undercontrolled personality prototypes, and these behaviors seem to characterize veterans who experience problems with depression and PTSD over time. A positive TBI status is directly and prospectively associated with PTSD symptomology independent of personality prototype. Implications for clinical interventions and future research are discussed.

Monte Carlo simulations of the relative biological effectiveness for DNA double strand breaks from 300 MeV u(-1) carbon-ion beams

Monte Carlo simulations are used to calculate the relative biological effectiveness (RBE) of 300 MeV u(-1) carbon-ion beams at different depths in a cylindrical water phantom of 10 cm radius and 30 cm long. RBE values for the induction of DNA double strand breaks (DSB), a biological endpoint closely related to cell inactivation, are estimated for monoenergetic and energy-modulated carbon ion beams. Individual contributions to the RBE from primary ions and secondary nuclear fragments are simulated separately. These simulations are based on a multi-scale modelling approach by first applying the FLUKA (version 2011.2.17) transport code to estimate the absorbed doses and fluence energy spectra, then using the MCDS (version 3.10A) damage code for DSB yields. The approach is efficient since it separates the non-stochastic dosimetry problem from the stochastic DNA damage problem. The MCDS code predicts the major trends of the DSB yields from detailed track structure simulations. It is found that, as depth is increasing, RBE values increase slowly from the entrance depth to the plateau region and change substantially in the Bragg peak region. RBE values reach their maxima at the distal edge of the Bragg peak. Beyond this edge, contributions to RBE are entirely from nuclear fragments. Maximum RBE values at the distal edges of the Bragg peak and the spread-out Bragg peak are, respectively, 3.0 and 2.8. The present approach has the flexibility to weight RBE contributions from different DSB classes, i.e. DSB0, DSB+ and DSB++.

Inhibition of plant vacuolar H(+)-ATPase by diethylpyrocarbonate

Treatment of the tonoplast H(+)-ATPase from mung bean seedlings (Vigna radiata L.) with histidine-specific modifier, diethyl pyrocarbonate (DEP), caused a marked loss of the ATP hydrolysis activity and the proton translocation in a concentration-dependent manner. The reaction order of inhibition was calculated to be 0.98, suggesting that at least one histidine residue of vacuolar H(+)-ATPase was modified by DEP. The absorbance of the vacuolar H(+)-ATPase at 240 nm was progressively increased after incubation with DEP, suggesting that N-carbethoxyhistidine had been formed. Hydroxylamine, which could break N-carbethoxyhistidine, reversed the absorbance change and partially restored the enzymic activity. The pK(a) of modified residues of vacuolar H(+)-ATPase was kinetically determined to be 6.73, a value close to that of histidine. Thus, it is assuredly concluded that histidine residues of the vacuolar H(+)-ATPase were modified by DEP. Kinetic analysis showed that V(max) but not K(m) of vacuolar H(+)-ATPase was decreased by DEP. This result is interpreted as that the residual activity after DEP inhibition was primarily due to the unmodified enzyme molecules. Moreover, simultaneous presence of DEP and DCCD (N,N'-dicyclohexyl-carbodiimide), an inhibitor modified at proteolipid subunit of vacuolar H(+)-ATPase, did not induce synergistic inhibition, indicating their independent effects. The stoichiometry studies further demonstrate that only one out of four histidine residues modified was involved in the inhibition of vacuolar H(+)-ATPase by DEP. Mg(2+)-ATP, the physiological substrate of vacuolar H(+)-ATPase, but not its analogs, exerted preferentially partial protection against DEP, indicating that the histidine residue involved in the inhibition of enzymatic activity may locate at/or near the active site and directly participate in the binding of the substrate.

A lysine residue involved in the inhibition of vacuolar H(+)-pyrophosphatase by fluorescein 5'-isothiocyanate

Vacuolar proton pumping pyrophosphatase (H(+)-PPase; EC 3.6.1.1) plays a central role in the electrogenic translocation of protons from cytosol to the vacuole lumen at the expense of PP(i) hydrolysis. A fluorescent probe, fluorescein 5'-isothiocyanate (FITC), was used to modify a lysine residue of vacuolar H(+)-PPase. The enzymatic activity and its associated H(+) translocation of vacuolar H(+)-PPase were markedly decreased by FITC in a concentration-dependent manner. The inhibition of enzymatic activity followed pseudo-first-order rate kinetics. A double-logarithmic plot of the apparent reaction rate constant against FITC concentration yielded a straight line with a slope of 0.89, suggesting that the alteration of a single lysine residue on the enzyme is sufficient to inhibit vacuolar H(+)-PPase. Changes in K(m) but not V(max) values of vacuolar H(+)-PPase as inhibited by FITC were obtained, indicating that the labeling caused a modification in affinity of the enzyme to its substrate. FITC inhibition of vacuolar H(+)-PPase could be protected by its physiological substrate, Mg(2+)-PP(i). These results indicate that FITC might specifically compete with the substrate at the active site and the FITC-labeled lysine residue locates probably in or near the catalytic domain of the enzyme. The enhancement of fluorescence intensity and the blue shift of the emission maximum of FITC after modification of vacuolar H(+)-PPase suggest that the FITC-labeled lysine residue is located in a relatively hydrophobic region.

Comparative study on the ALA photodynamic effects of human glioma and meningioma cells

BACKGROUND AND OBJECTIVE

The purpose of this study was to compare the differential susceptibility to photodynamic therapy (PDT) mediated damage in human U-105MG glioma cells and CH-157MN meningioma cells in vitro using 5-amino-levulinic acid (ALA) as photosensitizer, and to determine if growth factors would enhance PDT-mediated damage of these cells.

STUDY DESIGN/MATERIALS AND METHODS

U-105MG or CH-157MN cells were irradiated with polychromatic light in the presence of ALA. A Xenon lamp (150 W) was used as the light source. For the study on the effect of growth factor on ALA-PDT, cells were cultured in serum free medium for 24 hours. Epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), or platelet derived growth factor BB (PDGF-BB) was added to achieve a final concentration of 50 ng/ml. 30 minutes later, cells were incubated with ALA (100 microg/ml) for 24 hours, washed, and irradiated with light (11 J/cm2). MTT tetrazolium assays were performed 24 hours after light irradiation.

RESULTS

The inhibition of metabolic cellular function in U-105MG cells by ALA depended on both light energy density and ALA concentration. The susceptibility to ALA-PDT was profoundly lower for CH-157MN meningioma cells than U-105MG glioma cells. When incubated with ALA (100 microg/ml), U-105MG cells exhibited an LD50 around 8 J/cm2 of light irradiation, whereas that of CH-157MN cells was more than 25 J/cm2. EGF, bFGF, or PDGF-BB did not have any effects on the susceptibility of these two cell lines to ALA-PDT.

CONCLUSION

ALA-PDT was more effective in killing U-105MG glioma cells than CH-157MN meningioma cells. The differential susceptibility was likely due to differential accumulation of PpIX in these cells. EGF, bFGF, or PDGF-BB did not have stimulatory or inhibitory effect on the efficiency of ALA-PDT.

Regulation of vascular endothelial growth factor secretion in human meningioma cells

Previously, we induced vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) secretion in glioma cell lines by using physiologic concentrations of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), or platelet-derived growth factor-BB (PDGF-BB). We hypothesized that VEGF/VPF might enhance the blood supply required for the unregulated growth of tumors, and that it acts as the central mediator of tumor angiogenesis. The objective of this study was to determine whether the expression of VEGF/VPF by meningiomas is regulated by growth factors or sex hormones. By means of an enzyme-linked immunosorbent assay of CH-157MN meningioma cell supernatants, we demonstrated that EGF and bFGF similarly induce VEGF secretion by CH-157MN meningioma cells. At the maximum concentrations of EGF (50 ng/mL) and bFGF (50 ng/mL) used in this study, VEGF secretion was induced to 140% to 160% above baseline constitutive secretion. PDGF-BB homodimer did not enhance VEGF secretion significantly. Estradiol (up to 10(-7) mol/L), progesterone (up to 10(-5) mol/L), or testosterone (up to 10(-5) mol/L) did not stimulate or inhibit VEGF secretion in CH-157MN meningioma cells (p > 0.05). Furthermore, we demonstrated that dexamethasone decreased VEGF secretion to 32% of baseline constitutive secretion. This might explain the effect of corticosteroids in alleviating peritumoral brain edema in meningiomas. These results suggest that VEGF secretion in CH-157MN meningioma cells is mainly regulated by growth factors and corticosteroids, but not by sex hormones. Understanding the regulation of VEGF/VPF secretion in meningiomas might contribute to the development of a new therapeutic strategy.

Mutational analysis of the conserved cationic residues of Bacillus stearothermophilus 6-phosphoglucose isomerase

The importance in catalysis of the conserved arginine (R207) and lysine residues (K144, K294, K356, and K425) of 6-phosphoglucose isomerase from Bacillus stearothermophilus was assessed by site-directed mutagenesis and kinetic analysis. In general mutations had minor effects on the Km for fructose 6-phosphate. More dramatic effects were seen on kcat. The R207A mutant had a five orders of magnitude decrease in kcat relative to the wild-type enzyme. There was a significant recovery, by three orders of magnitude, in the kcat for the R207K mutant. The results suggest that the positive charge provided by R207 plays a critical role in the isomerization reaction. K425 was substituted with alanine, valine, phenylalanine, tryptophan and aspartate. All mutant enzymes at position 425 had kcat decreased in the range of several-hundred-fold. For the other mutants, K294A and K144A, the kcat values were 3.5% and 27% of the wild-type enzyme, respectively. No effects on catalysis were observed for the K356A mutant. The results suggest that R207, K144, K294, and K425 are located in the active site of the enzyme. The active-site location and the catalytic roles of K425 and K294 are supported further by the inhibitory effects of pyridoxal 5'-phosphate on enzymatic activities. The data also confirm the importance of K425 and K144 anticipated by the affinity labeling studies of the corresponding residues by pyridoxal 5'-phosphate in pig muscle phosphoglucose isomerase.

Expression, purification, and crystallization of two isozymes of 6-phosphoglucose isomerase of Bacillus stearothermophilus

Two isozymes of 6-phosphoglucose isomerase (phosphoglucose isomerase A & phosphoglucose isomerase B), isolated from Bacillus stearothermophilus, have been overexpressed in Escherichia coli strain DF2145 and purified to homogeneity. Crystals of both isozymes have been obtained by the vapor diffusion method. The crystals of phosphoglucose isomerase A have unit cell dimensions a = b = 132.0 A, c = 183.6 A, and diffract to about 2.8 A resolution. An analysis of the reflection data indicates that the crystal system is hexagonal, space group P6122 or P6522. The crystals of phosphoglucose isomerase B complexed with 6-phosphogluconate belong to the orthorhombic space group I222 (or I212121), with cell dimensions a = 75.1 A, b = 95.7 A, c = 171.5 A, and diffract to a resolution of 2.3 A. These crystals promise to yield more detail for the substrate recognition and higher resolution structures of 6-phosphoglucose isomerase.

Palmar hyperhidrosis in children: treatment with video endoscopic laser sympathectomy

Palmar hyperhidrosis (PH) often starts in childhood and can be a disabling condition for a significant number of young children at the age they begin primary school. There are few reports regarding the surgical treatment of PH in children. The authors report on 40 PH patients under 16 years of age treated with video thoracoscopic laser sympathectomy; there has been substantial experience with this procedure for the treatment of adults with PH. A satisfactory result, with very low morbidity, was achieved for all 40 children. The surgical technique is described briefly. With the technique, the proper sympathetic segment is visualized in almost all cases and then definitely ablated with a fiberoptic low-power laser while under the aid of sympathetic monitoring. Consequently, an adequate sympathectomy warranting a long-lasting therapeutic effect can be achieved without the need of tissue diagnosis. No case required conversion to open sympathectomy. Neither injury to the lung nor bleeding was encountered. Horner's syndrome did not occur in any case. Bilateral sympathectomy was accomplished generally within 30 minutes. All patients were discharged after an overnight stay and are doing well with normal activities. The most frequent complication was compensatory hyperhidrosis, which was tolerable after reassurance. Based on the accumulated experience, it is justified to recommend early surgery, with this refined technique, in cases of severe PH in children.

Autonomic activities in hyperhidrosis patients before, during, and after endoscopic laser sympathectomy

Three hundred palmar hyperhidrosis (PH) patients have been treated with video endoscopic laser sympathectomy during the last 2 years. Monitoring the palmar skin perfusion (PSP) and palmar skin temperature (PST) has been used intraoperatively to aid the confirmation of the correct sympathetic segment for laser ablation. The preoperative and postoperative PSP and PST and sympathetic skin response (SSR) also have been measured to evaluate the therapeutic effect of this method. An apparent increase of PSP would occur intraoperatively after the interruption of the T2 sympathetic segment, and then a gradual elevation of PST would follow after the extirpation of the segment. A rise of PST of about 3 degrees C after laser ablation of the appropriate segment indicated sufficient denervation of the hand and predicted long-lasting relief of PH. Furthermore, both PSP and PST also significantly increased after the operation. The postoperative elevation of the PST (usually about 3 degrees C) is similar to that recorded during intraoperative monitoring. The amplitude and the latency of SSR in the palm and sole were recorded both before and after sympathectomy. A remarkable decrease of palmar SSR amplitude and its ratio was found postoperatively by comparing it with that of plantar SSR in the same patient. These autonomic activity changes have correlated well with the postoperative satisfaction of the patients. Based on our study, the anatomic identification confirmed by the sympathetic monitorings has proved essential to achieve a definite and adequate sympathectomy leading to a satisfactory resolution of PH without the need of a tissue diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Video thoracoscopic laser sympathectomy for palmar hyperhidrosis

Palmar hyperhidrosis (PH) is common in Orientals from subtropical areas. Many therapeutic modalities are used in practice, but none has proved to be entirely satisfactory. We have developed a new therapeutic technique by combining a video thoracoscopic system with a surgical laser unit (both waveguide CO2 laser and fibre-optic Nd:YAG laser). The operation was performed under general anaesthesia with alternative one-lung ventilation. With this technique, we are able to identify the sympathetic trunk on the TV screen and confirm its proper level with accurate ablation by intraoperative vasomotor monitoring. Consequently, an adequate sympathectomy can be definitely achieved through laser extirpation. We have successfully treated 300 PH patients with this technique from 1990 to 1992. The ages ranged from six to 63 years with a mean of 26.6. There were 125 males and 175 females. Most patients underwent en bloc ablation of the T2 segment which includes a major part of the T2 ganglion with its adjacent trunk which overlays the T2 rib head. All of them obtained a satisfactory relief of PH except 13 patients. The procedure did not result in a change of vital signs. There was neither obvious injury to lung nor bleeding. No Horner's syndrome was produced. The commonest complication was compensatory hyperhidrosis in various degrees encountered in about half of the cases. Two-thirds of the patients were followed up for more than 12 months and only three had recurrence. Based on our experience, the technique is considered to be a minor and safe procedure and able to achieve a definite and long-lasting therapeutic effect. It causes minimal discomfort and scarring. Particularly, the operation time and hospital stay were markedly shortened in comparison with other conventional open sympathectomy procedures.

Fluorospectral study of the rat brain and glioma in vivo

An animal model of cerebral glioma was utilized by implanting C6 glioma cells into the brains of adult Wistar rats. Once tumors developed to 7-12 mm in diameter, we conducted continuous fluorimetry monitoring of glioma up to 24 hours using a fibre-optic system connected to an intensified multichannel photodetector after an intravenous injection of hematoporphyrin derivative (HPD) into the rats. The intensity of the fluorescence in normal brain reached a plateau 6 hours after intravenous injection of HPD while that in glioma reached a plateau 80 minutes after injection. These fluorescence intensities of glioma, brain adjacent to tumor (BAT), and surrounding normal brain were measured in vivo 24 hours after intravenous administration of 5 mg/kg of HPD. The ratio of fluorescence intensities between glioma and brain was 6.1 while the ratio between BAT and brain was 3.9. There were no obvious differences in shapes between the spectra of the natural fluorescence (autofluorescence) of rat glioma and brain but the intensity of autofluorescence was much weaker in glioma. There are many problems in spectroscopic studies of biological tissues in vivo. It cannot be overemphasized that very strict criteria must be applied in order to get accurate data. Fluorescence from HPD administration may be used to discriminate tumor tissue from surrounding normal brain tissue during operation if the measuring conditions could be kept constant. It is important to understand the photospectral properties of glioma and brain tissue in order to get the most benefits in clinical application of light-induced fluorescence or photoradiation therapy.

Antitumor activity of tetraacetylglucosamine mustard

1,3,4,6-Tetra-O-acetyl-2-(di-2-chloroethyl)amino-2-deoxy-D-glucopyranose is active against L1210 leukemia, giving over 100% increased life-span at optimal dose. Against P388 leukemia, it gives 200% increased life-span with long-term survivors. The compound is most active when given i.p., but shows some activity when given s.c. than p.o., and is more potent (therapeutic and toxic effect) than mechlorethamine on both a molar and a mg basis. Of importance, the schedule dependency for the administration of 1,3,4,6-tetra-O-acetyl-2-(di-2-chloroethyl)amino-2-deoxy-D-glucopyranose in L1210 leukemia differs from most alkylating agents in that it is best given by multiple daily injections rather than as a single large injection on Day 1. This characteristic can be attributed to the amino-glucose moiety.

Synthfsis of bis(aziridinyl)phosphinyl-N-hydroxyurethane derivatives as antineoplastic agents

Several new "dual antagonists" were synthesized in which the 2,2-dimethyl (or ring C unsubstituted) aziridine phosphinyl function is linked to N-hydroxyurethane rather than the urethane moiety. Three of the new compounds showed very high activities against leukemia L1210 in mice.