Coping with the stress of a painful medical procedure.

To evaluate its effect on procedure-related distress, the focus of attention was manipulated by providing training to hospitalized acute burn patients (n=42). Participants were randomly assigned to attention focusing (i.e. attending to procedural sensations) or music distraction (i.e. attention diverting) coping interventions, or to usual care during the target dressing change. Coping behavior (i.e. distraction, focusing, and three confounding methods, ignoring, catastrophizing, reinterpreting), tension and intrusiveness were evaluated 24 h retrospectively (i.e. for the prior procedure), during the targeted procedure, and 30 min after the target procedure. When coping during the target procedure by ignoring, reinterpreting, and catastrophizing were covaried, the music distraction group experienced significantly fewer intrusions, and the attention focus group had more intrusions. Additionally, secondary analyses revealed that coping by ignoring during the prior day's procedure significantly predicted higher procedural tension during, and more intrusions following, the targeted procedure. Suppression-based forms of emotion-focused coping may be enhanced by training in the use of an explicit distractor.

Differential gene regulation in human versus rodent hepatocytes by peroxisome proliferator-activated receptor (PPAR) alpha. PPAR alpha fails to induce peroxisome proliferation-associated genes in human cells independently of the level of receptor expresson.

We compared the ability of rat and human hepatocytes to respond to fenofibric acid and a novel potent phenylacetic acid peroxisome proliferator-activated receptor (PPAR) alpha agonist (compound 1). Fatty acyl-CoA oxidase (FACO) activity and mRNA were increased after treatment with either fenofibric acid or compound 1 in rat hepatocytes. In addition, apolipoprotein CIII mRNA was decreased by both fenofibric acid and compound 1 in rat hepatocytes. Both agonists decreased apolipoprotein CIII mRNA in human hepatocytes; however, very little change in FACO activity or mRNA was observed. Furthermore, other peroxisome proliferation (PP)-associated genes including peroxisomal 3-oxoacyl-CoA thiolase (THIO), peroxisomal enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase (HD), peroxisomal membrane protein-70 (PMP-70) were not regulated by PPAR alpha agonists in human hepatocytes. Moreover, other genes that are regulated by PPAR alpha ligands in human hepatocytes such as mitochondrial HMG-CoA synthase and carnitine palmitoyl transferase-1 (CPT-1) were also regulated in HepG2 cells by PPAR alpha agonists. Several stably transfected HepG2 cell lines were established that overexpressed human PPAR alpha to levels between 6- and 26-fold over normal human hepatocytes. These PPAR alpha-overexpressing cells had higher basal mRNA levels of mitochondrial HMG-CoA synthase and CPT-1; however, basal FACO mRNA levels and other PP-associated genes including THIO, HD, or PMP-70 mRNA were not substantially affected. In addition, FACO, THIO, HD, and PMP-70 mRNA levels did not increase in response to PPAR alpha agonist treatment in the PPAR alpha-overexpressing cells, although mitochondrial HMG-CoA synthase and CPT-1 mRNAs were both induced. These results suggest that other factors besides PPAR alpha levels determine the species-specific response of human and rat hepatocytes to the induction of PP.

Mitochondrial DNA metabolism targeting drugs.

Numerous drugs are known to deplete mitochondrial DNA (mtDNA) from mammalian cells. These include DNA polymerase gamma and type II topoisomerase inhibitors, lipophilic cationic compounds, and DNA intercalating and non intercalating agents. The effects of these drugs on mtDNA metabolism will be discussed and potential mechanisms underlying their depletion of mtDNA presented.

Brief cognitive interventions for burn pain.

This study tested the efficacy of 2 brief cognitive interventions in supplementing regular medical treatment for pain during burn dressing change. Forty-two burn inpatients were randomly assigned to 3 groups: sensory focusing, music distraction, and usual care. Patients reported pain, pain relief satisfaction with pain control, and pain coping strategies. The sensory focusing group reported greater pain relief compared to the music distraction group and a reduction in remembered pain compared to the usual care group, although group differences were not observed on serial pain ratings. In addition, after controlling for burn size and relevant covariates, regression analyses indicated that catastrophizing predicted pain, memory for pain, and satisfaction with pain control. Refinement of the sensory focusing intervention is warranted to reduce catastrophic thinking and improve pain relief

Tumor necrosis factor alpha is not required for WY14,643-induced cell proliferation.

It has been proposed that the cytokine tumor necrosis factor alpha (TNFalpha) stimulates peroxisome proliferator-induced hepatic cell proliferation. To test this hypothesis, induction of peroxisome proliferation and hepatocyte proliferation were compared in wild-type C57Bl/6 and TNFalpha knockout mice. Animals were dosed with either vehicle or 100 mg/kg/day WY14,643 by oral gavage for 4 days. Liver to brain weight ratios increased in both wild-type and TNFalpha knockout animals after WY14,643 administration. In addition, WY14,643-treated wild-type C57Bl/6 and TNFalpha knockout mice displayed marked hepatic induction of fatty acyl-CoA oxidase activity (approximately 8-fold) and mRNA content (approximately 5-fold). Electron microscopic examination confirmed increased numbers of peroxisomes in hepatocytes in both mouse models. Moreover, WY14,643 markedly induced hepatic cell proliferation (approximately 15-fold) in both wild-type C57Bl/6 and TNFalpha knockout mice as measured by bromodeoxyuridine incorporation into hepatocyte nuclei. In addition, a 50% decrease in TNFalpha mRNA was observed in wild-type mice after treatment with WY14,643. These results suggest that the hepatocellular proliferation induced after peroxisome proliferator treatment occurs independently of TNFalpha signaling.

Dexamethasone selectively inhibits WY14,643-induced cell proliferation and not peroxisome proliferation in mice.

It has been proposed that the hepatocellular proliferation induced by peroxisome proliferators may occur through an indirect mechanism involving cytokine release as opposed to direct regulation of cell growth genes by PPARalpha. We compared the induction of peroxisome proliferation and cell proliferation in C57Bl/6 mice treated with 100 mg/kg/day WY14,643 in the presence or absence of increasing doses of dexamethasone (DEX), an inhibitor of the release of proinflammatory cytokines. Biochemical markers of peroxisome proliferation, including fatty acyl-CoA oxidase activity, CYP4A content, and liver-to-body-weight ratios were markedly increased in the WY14,643-treated mice. DEX coadministration, up to a maximum dose of 50 mg/kg/day, did not prevent the induction of these parameters. Acyl-CoA oxidase mRNA levels increased 5-fold with WY14,643 treatment and 15-fold with DEX coadministration at 5 mg/kg/day. ApoCIII mRNA levels were decreased by 50% in WY14,643-treated mice. DEX alone at 5 mg/kg/day increased the ApoCIII mRNA 4-fold, but WY14,643 coadministration also inhibited this induction by greater than 50%. In addition, immunohistochemical detection of peroxisomes with anti-PMP-70 antibody demonstrated marked increase in hepatocellular peroxisomes in WY14,643-treated mice regardless of DEX treatment. In contrast, coadministration of DEX at 2 mg/kg/day partially inhibited the hepatocyte proliferation response (measured by BrdU incorporation or Ki-67 immunohistochemical detection). Moreover, DEX at doses of 5 mg/kg/day or higher completely inhibited the induction of cell proliferation and, at these higher doses, reduced the cell proliferation rate to levels below the vehicle-treated control mice. Our studies clearly demonstrate that the hepatocellular proliferation induced by a peroxisome proliferator can be modulated independently of the other pleiotropic effects usually induced by these agents, suggesting an indirect mechanism of hyperplasia.

Ligand-dependent interaction of hepatic fatty acid-binding protein with the nucleus.

Our studies were conducted to explore the role of hepatic fatty acid-binding protein (L-FABP) in fatty acid transport to the nucleus. Purified rat L-FABP facilitated the specific interaction of [(3)H]oleic acid with the nuclei. L-FABP complexed with unlabeled oleic acid decreased the nuclear association of [(3)H]oleic acid:L-FABP; however, oleic acid-saturated bovine serum albumin (BSA) or fatty acid-free L-FABP did not. The peroxisome-proliferating agents LY171883, bezafibrate, and WY-14,643 were also effective competitors when complexed to L-FABP. Nuclease treatment did not affect the nuclear association of [(3)H]oleic acid:L-FABP; however, proteinase treatment of the nuclei abolished the binding. Nuclei incubated with fluorescein-conjugated L-FABP in the presence of oleic acid were highly fluorescent whereas no fluorescence was observed in reactions lacking oleic acid, suggesting that L-FABP itself was binding to the nuclei. The nuclear binding of FABP was concentration dependent, saturable, and competitive. LY189585, a ligand for L-FABP, also facilitated the nuclear binding of fluorescein-conjugated L-FABP, although it was less potent than oleic acid. A structural analog that does not bind L-FABP, LY163443, was relatively inactive in stimulating the nuclear binding. Potential interactions between L-FABP and nuclear proteins were analyzed by Far-Western blotting and identified a 33-kDa protein in the 500 mm NaCl extract of rat hepatocyte nuclei that bound strongly to biotinylated L-FABP. Oleic acid enhanced the interaction of L-FABP with the 33-kDa protein as well as other nuclear proteins. We propose that L-FABP is involved in communicating the state of fatty acid metabolism from the cytosol to the nucleus through an interaction with lipid mediators that are involved in nuclear signal transduction.

Personality predictors of injury-related posttraumatic stress disorder.

This longitudinal, cohort study examined the effect of personality traits on the emergence of posttraumatic stress disorder (PTSD) in a recently traumatized, civilian, mixed-gender sample with significant injuries. Burn survivors (N = 70) were administered the NEO-Personality Inventory (NEO-PI) and the Structured Clinical Interview for DSM III-R (SCID) at hospital discharge and readministered the SCID 4 and 12 months later. Overall, the sample of burn survivors scored significantly higher on neuroticism and extraversion and lower on openness, agreeableness, and conscientiousness relative to a normative national sample. Furthermore, multivariate analysis of variance revealed that PTSD symptom severity groups (i.e., single symptom, multiple symptoms, subthreshold PTSD, PTSD) were differentially related to neuroticism and extraversion. Planned comparisons indicated that neuroticism was higher and extraversion was lower in those who developed PTSD compared with those who did not develop PTSD.

Effect of early body image dissatisfaction on subsequent psychological and physical adjustment after disfiguring injury.

OBJECTIVE: The impact of body image dissatisfaction on quality of life after severe burn injury was investigated after controlling for other determinants of outcome (i.e., injury, distress, and preburn quality of life). METHODS: The postburn quality of life (2-months postdischarge) of groups with and without body image dissatisfaction was studied after controlling for preburn quality of life (measured 2-3 days postadmission). The patient population (N = 86) was 77.9% men, had an average total body surface area burned of 17.02%, and average full-thickness burn of 6.09%. Forty percent had facial injuries, 68.6% required surgery, most were injured by flame (39.5%), and 76.8% were employed. RESULTS: Multivariate analysis of covariance (covarying preburn level of Mental quality of life, facial injury, and size of burn) contrasting body image dissatisfaction groups found significantly lower psychosocial adjustment at 2-month follow-up in those with greater body image dissatisfaction (multivariate F = 3.61; p<.01). A second MANCOVA (covarying the preburn level of Physical quality of life and both facial injury and size of burn) found significantly lower physical functioning at 2-month follow-up in those with greater body image dissatisfaction (multivariate F = 2.78; p < .03). Adding two more covariates (depression and posttrauma distress) eliminated the effect of body image dissatisfaction on postburn Physical but not Mental adjustment. CONCLUSIONS: Body image dissatisfaction affects quality of life after severe burn injury. Distress moderates this impact on aspects of physical but not psychosocial health.

Prolonged adjustment difficulties among those with acute posttrauma distress following burn injury.

This study examined the impact of mild to moderate symptoms of in-hospital posttrauma distress (PTD) following severe burn injury on quality of life (QOL) at 2-month follow-up after controlling for preburn QOL, injury severity, and state Negative Affectivity (depression, body image dissatisfaction) and dispositional optimism-pessimism. Participants' (n = 86) self-report established PTD and non-PTD groups (median split on Davidson Trauma Scale). After covarying preburn level of psychosocial QOL, PTD groups differed on psychosocial functioning at follow-up. This effect remained after covarying injury severity, state NA, dispositional optimism-pessimism, and preburn Mental domain QOL. PTD groups also differed significantly on physical functioning at follow-up after covarying preburn physical functional status. This effect was removed by controlling preburn Physical domain QOL and either injury severity or state NA and dispositional optimism-pessimism. Therefore, PTD is related to significant impairments in the physical and psychosocial adjustment of survivors of severe burns regardless of pretrauma level of adjustment. Injury severity and state NA and dispositional optimism-pessimism moderate the impact of PTD on physical but not psychosocial adjustment.

The 1998 Clinical Research Award. Sleep disturbance after burn injury: a frequent yet understudied complication.

This study investigated the frequency of sleep disturbance of burn survivors at 3 time points: during hospitalization (time 1: n = 237), 1 week after discharge (time 2: n = 149), and 2 months after discharge (time 3: n = 91). Predictors of sleep disturbance and its relationship to quality of life are explored. Measures of sleep, post-traumatic stress disorder, depression, anxiety, pain, and quality of life were administered at each time point. Fifty percent of participants had sleep disturbance while in the hospital and 1 week after discharge. Forty percent of participants continued to have sleep disturbance 2 months after discharge. In regression equations, emotional distress was a better predictor of sleep disturbance than pain and total body surface area burned at each time point. Sleep disturbance was significantly negatively correlated with all aspects of quality of life represented on the SF-36 Health Survey. Sleep disturbance is a common and often chronic postburn complication that warrants further research.

Delayed cytotoxicity and cleavage of mitochondrial DNA in ciprofloxacin-treated mammalian cells.

We have previously shown that 4-quinolone drugs cause a selective loss of mitochondrial DNA (mtDNA) from mouse L1210 leukemia cells. The loss in mtDNA was associated with a delayed loss in mitochondrial function. Here, we report that the 4-quinolone drug ciprofloxacin is cytotoxic to a variety of cultured mammalian cell lines at concentrations that deplete cells of mtDNA. The IC50 values for ciprofloxacin varied from 40 to 80 micrograms/ml depending on the cell line tested. Cytotoxicity required continuous exposure of cells to drug for 2-4 days, which corresponded to approximately three or four cell doublings. Shorter times of drug exposure did not cause significant cytotoxicity. In addition, cells became drug resistant when they were grown under conditions that bypassed the need for mitochondrial respiration. Resistance was not due to a decrease in cellular drug accumulation, suggesting that ciprofloxacin cytotoxicity is caused by the loss of mtDNA-encoded functions. Analysis of mtDNA from ciprofloxacin-treated cells revealed the presence of site-specific, double-stranded DNA breaks. Furthermore, exonuclease protection studies indicated that the 5'-, but not the 3'-, ends of the drug-induced DNA breaks were tightly associated with protein. These results suggest that ciprofloxacin may be causing cytotoxicity by interfering with a mitochondrial topoisomerase II-like activity, resulting in a loss of mtDNA.

Early avoidance of traumatic stimuli predicts chronicity of intrusive thoughts following burn injury.

The role of avoidance behavior in perpetuating the experience of intrusive thoughts among burn survivors was investigated. The Impact of Events Scale (IES), which has subscales that measure the frequency of intrusive thoughts and avoidance behavior, was administered to burn survivors (n = 23) upon discharge and four months later. Both avoidance behavior and intrusive thoughts at discharge were significantly related to experiencing intrusive thoughts at four months (r = 0.59, P < 0.003, r = 0.45, P < 0.03, respectively). In a hierarchical regression analysis controlling for intrusive thoughts at discharge, avoidance behavior continued to significantly predict intrusive thoughts at four months [B = 0.43, t(20) = 2.9, P < 0.009]. Limitations of the study and implications for treatment are discussed.

Short-term effects of research participation on college men.

College students in a social science core curriculum course were given an option of completing a packet of psychological inventories and demographic questions. The last inventory in the packet, the Lazarus Stress Questionnaire, evaluated the emotional impact of answering the questionnaires. Positive feelings were endorsed significantly more than negative feelings. Further analyses, using the Eysenck Personality Questionnaire and the Life Experiences Survey, revealed characteristics that may predispose participants to positive or negative emotional reactions to participation in research. Results are discussed in terms of self-focus mechanisms and ethical standards in the treatment of students who participate in research.

Nafenopin-induced peroxisome proliferation in vitamin A deficient rats.

Induction of peroxisome proliferator responsive genes is thought to be mediated through binding of a peroxisome proliferator-activated receptor (PPAR) to specific peroxisome proliferator response elements in the upstream region of these genes. Binding of PPAR to the acyl-CoA oxidase promoter requires heterodimerization with the retinoid X receptor (RXR), and subsequent transactivation is strongest when ligands for both PPAR and RXR are present. Therefore, we hypothesized that depletion of ligand for the retinoid receptor would limit the induction of peroxisome proliferation in rats. Hepatic retinol content was reduced by more than 90% by feeding weanling rats a vitamin A deficient (VAD) diet for approximately 3 months. Nafenopin treatment for 7 days induced peroxisomal beta-oxidation 18-fold in VAD rats compared with 16-fold in rats fed a vitamin A sufficient (VAS) diet. Nafenopin induced microsomal laurate hydroxylase and mitochondrial beta-oxidation to comparable rates of specific activity in both VAD and VAS rats. However, the activities in VAD controls were significantly lower than in VAS controls, so the magnitude of the nafenopin-induced increases was greater in the VAD rats. Relative liver weights were increased nearly 2-fold in both VAS and VAD rats treated with nafenopin. Ultrastructural examination of the livers demonstrated that nafenopin increased the number and size of peroxisomes in both VAD and VAS rats. These data demonstrate that rats with severely depleted vitamin A stores remained responsive to the peroxisome proliferator nafenopin. Whether critical retinoid pools that supply RXR ligand (9-cis-retinoic acid) are spared in the vitamin A deficient rats remains to be determined.

4-Quinolones cause a selective loss of mitochondrial DNA from mouse L1210 leukemia cells.

The 4-quinolone antibiotics nalidixic acid and ciprofloxacin are potent inhibitors of the bacterial type II topoisomerase DNA gyrase. Treatment of mouse L1210 leukemia cells with these drugs resulted in a delayed inhibition of cell proliferation. Prior to inhibition of cell proliferation, there was a time-dependent decrease in the cellular content of mitochondrial DNA (mtDNA). The decrease in mtDNA was associated with a decrease in the rate of mitochondrial respiration and an increase in the concentration of lactate in the growth medium. Inhibition of cell proliferation by 4-quinolones was reversible upon drug washout. However, there was a 2- to 4-day lag before the growth rate returned to normal levels. This was preceded by an increase in mtDNA content and mitochondrial respiration. These studies suggest that inhibition of mammalian cell proliferation by 4-quinolone drugs is related to the selective depletion of mtDNA.

Detection of mycotoxins by thin-layer chromatography: application to screening of fungal extracts.

A convenient thin-layer chromatographic screening procedure for the detection of 18 mycotoxins is described.