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Biomedical subjects

J DeLuca

Publications and source records attributed to J DeLuca.

At least 37 records · Page 2Linked to original sources
PubMed1999

Chronic fatigue syndrome: reviewing the research findings.

This article reviews the current state of research in chronic fatigue syndrome (CFS). The evolving definition, prevalence, and prognosis of this controversial illness are presented. We review studies examining psychiatric, personality, and psychosocial etiology for CFS. The evidence for pathophysiology in CFS is also presented, and studies investigating viral, immune, neuroimaging, neuroendocrine, and central and autonomic nervous system abnormalities in CFS are assessed. Current evidence indicates that CFS is multi-determined and heterogeneous and that subgrouping patients according to factors such as psychiatric state and symptom onset may be fruitful. The current state of treatment for CFS is reviewed, and the challenges for research aimed at resolving this prototypical mind/body problem are discussed.

Brain↗
PubMed1999

Is depression associated with immune activation?

BACKGROUND: Some research immunologists have suggested that major depression amd chronic fatigue syndrome (CFS) are characterized by immune activation. To test this hypothesis, we compared immunological function in patients with major depression and in patients with CFS who developed major depression after the onset of CFS to that of sedentary healthy controls. METHODS: Subjects completed the Centers for Epidemiological Study-Depression (CES-D) questionnaire and allowed venisection. We performed flow cytometric analysis on 13 groups of white blood cells and used a reverse transcriptase PCR method to assay m-RNA of eight cytokines. RESULTS: CES-D scores were high in both patient groups and did not differ significantly. We found no evidence for immune activation in either patient group. Instead the data suggested immunological downregulation in depression. LIMITATIONS: Not all the subjects in the two patient groups were off antidepressants. CONCLUSIONS: The data indicate that immune activation is not necessary in depression--either alone or with CFS.

Adult↗
PubMed1999

Pharmacologic considerations in the treatment of neonatal septicemia and its complications.

This article focuses on the pharmacologic properties of drugs commonly used in the treatment of neonatal septicemia and its complications. Rational therapy demands an awareness of not only the pharmacology of individual drugs but also the interactions and anticipated fate of such drugs in the rapidly changing physiologic environment of the neonate. Further research in the area of equine neonatal pharmacology should greatly assist our understanding of the impact of the disease state on the unique physiology of the newborn and should allow us to better predict the ultimate fate of drugs commonly used for such purposes. Careful dosing and close monitoring of pharmacologic effects are critical for a successful outcome. In the future, newer therapeutic strategies that are safe and efficacious may provide a means to circumvent many of the problems currently encountered with treating the septicemic newborn foal.

Animals↗
PubMed1999

Speed of information processing as a key deficit in multiple sclerosis: implications for rehabilitation.

Speed of information processing was assessed in patients with multiple sclerosis and healthy controls using both an auditory and visual task designed to control for accuracy of performance across groups. After controlling for accuracy of performance, patients with multiple sclerosis were found to have significantly slower speed of information processing relative healthy controls, irrespective of the modality of stimulus presentation (auditory or visual). When given an adequate amount of time to process information, however, the patients performed similarly to controls. These results suggest that persons with multiple sclerosis experience deficits specifically in processing speed but not performance accuracy. Results are discussed in terms of rehabilitative guidelines for the cognitive improvement of persons with multiple sclerosis.

Adult↗
PubMed1998

Influence of exhaustive treadmill exercise on cognitive functioning in chronic fatigue syndrome.

The purpose of this study was to determine the effect of exhaustive exercise on cognitive performance of patients with chronic fatigue syndrome (CFS) and sedentary healthy controls (CON). Subjects were 19 women with CFS and 20 CON. A test battery consisting of 4 cognitive tests (CTB) was given pre-, immediately post-, and 24 hours post-treadmill exercise to exhaustion. No differences were seen on the CTB pre-exercise. CFS patients improved at a slower rate than CON on the Symbol Digit Modalities Test (SDMT), Stroop Word Test (SWT), and Stroop Color Test (SCT). When compared with CON, a lower number of correct responses was seen for the CFS immediately postexercise on the SDMT (61 +/- 3 vs 66 +/- 2), SWT (137 +/- 6 vs 146 +/- 6), and SCT (99 +/- 4 vs 107 +/- 3), and 24 hours postexercise on the SDMT (64 +/- 3 vs 69 +/- 2), SWT (134 +/- 7 vs 148 +/- 5), and SCT (101 +/- 4 vs 106 +/- 3). We conclude that after physically demanding exercise, CFS subjects demonstrated impaired cognitive processing compared with healthy individuals.

Adult↗
PubMed1998

Neuroimaging in chronic fatigue syndrome.

The diagnosis of chronic fatigue syndrome (CFS) is made difficult by the absence of specific biomedical markers, and depends primarily on determining whether subjective information provided by the patient meets the clinical case definition of this syndrome. Reported cognitive difficulties and/or complaints of headache may instigate referral for brain imaging. This article will discuss the value of neuroimaging in evaluating CFS, specifically reviewing studies that (1) used static magnetic resonance imaging (MRI) to assess structural abnormalities; and (2) assessed regional cerebral blood flow (rCBF) via detection of Tc-99m hexamethylpropyl-eneamine oxime distribution by single-photon emission computed tomography (SPECT). Future research design considerations are explored including (1) the utilization of positron emission tomography (PET) and other emerging neuroimaging technologies; and (2) methodological concerns, i.e., the influence of psychopathology (such as depression) and neurologic disease (such as multiple sclerosis) as possible confounding factors.

Fatigue Syndrome, Chronic↗
PubMed1998

Do peroxisome proliferating compounds pose a hepatocarcinogenic hazard to humans?

The purpose of the workshop "Do Peroxisome Proliferating Compounds Pose a Hepatocarcinogenic Hazard to Humans?" was to provide a review of the current state of the science on the relationship between peroxisome proliferation and hepatocarcinogenesis. There has been much debate regarding the mechanism by which peroxisome proliferators may induce liver tumors in rats and mice and whether these events occur in humans. A primary goal of the workshop was to determine where consensus might be reached regarding the interpretation of these data relative to the assessment of potential human risks. A core set of biochemical and cellular events has been identified in the rodent strains that are susceptible to the hepatocarcinogenic effects of peroxisome proliferators, including peroxisome proliferation, increases in fatty acyl-CoA oxidase levels, microsomal fatty acid oxidation, excess production of hydrogen peroxide, increases in rates of cell proliferation, and expression and activation of the alpha subtype of the peroxisome proliferator-activated receptor (PPAR-alpha). Such effects have not been identified clinically in liver biopsies from humans exposed to peroxisome proliferators or in in vitro studies with human hepatocytes, although PPAR-alpha is expressed at a very low level in human liver. Consensus was reached regarding the significant intermediary roles of cell proliferation and PPAR-alpha receptor expression and activation in tumor formation. Information considered necessary for characterizing a compound as a peroxisome proliferating hepatocarcinogen include hepatomegaly, enhanced cell proliferation, and an increase in hepatic acyl-CoA oxidase and/or palmitoyl-CoA oxidation levels. Given the lack of genotoxic potential of most peroxisome proliferating agents, and since humans appear likely to be refractive or insensitive to the tumorigenic response, risk assessments based on tumor data may not be appropriate. However, nontumor data on intermediate endpoints would provide appropriate toxicological endpoints to determine a point of departure such as the LED10 or NOAEL which would be the basis for a margin-of-exposure (MOE) risk assessment approach. Pertinent factors to be considered in the MOE evaluation would include the slope of the dose-response curve at the point of departure, the background exposure levels, and variability in the human response. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Parallel solution synthesis of pyridinethiones, pyridinones and thienopyridines.

The parallel solution synthesis of three classes of heterocycles is described. Arrays of pyridinethiones, pyridinones and thienopyridines were prepared using one-step chemistry starting from readily accessible building blocks. The latter class of compounds was accessed by utilising a library-from-library approach.

Combinatorial Chemistry Techniques↗
PubMed1998

Acquisition and storage deficits in multiple sclerosis.

This study examined whether verbal and visual memory impairments in multiple sclerosis (MS) are attributable to deficits in acquisition, storage, or retrieval. Volunteers with MS (n = 40) and healthy controls (n = 20) rehearsed a word list and a checkerboard pattern using a selective reminding procedure until two consecutive error-free trials were attained. Recall and recognition were assessed after 30 min and 90 min (and 1 week for verbal material) delays. The MS group required significantly more trials to attain criterion on both learning tests. Once equated for acquisition, both groups performed similarly on verbal recall and recognition. However the MS group performed significantly worse on measures of visual recall and recognition. The results suggest that the verbal memory impairment in MS is due to deficient acquisition, while the visual memory impairment in MS is attributable to deficits in acquisition and storage.

Adult↗
PubMed1998

Relation between neuropsychological impairment and functional disability in patients with chronic fatigue syndrome.

OBJECTIVES: To examine the relation between neuropsychological impairment and functional disability in patients with chronic fatigue syndrome, and determine whether the relation is independent of psychiatric factors. METHODS: The subjects were 53 patients with chronic fatigue syndrome and 32 healthy controls who did not exercise regularly. Subjects were administered a structured psychiatric interview and completed questionnaires focusing on depression and functional disability. They also completed a battery of standardised neuropsychological tasks focusing on the cognitive domains that patients with chronic fatigue syndrome experience as particularly difficult: memory (verbal and visual), and attention/concentration. A test score was defined as failing when it was > or =2 SD below the mean of the healthy controls after controlling for demographic factors. RESULTS: Those patients with chronic fatigue syndrome with higher numbers of failing neuropsychological test scores reported significantly more days of general inactivity in the past month than those with fewer failing scores. This result remained significant even after partialling out the contribution of the presence of a comorbid axis I psychiatric episode and the overall level of depressive symptomology. Patients with failing verbal memory scores were particularly functionally disabled compared with those with passing scores. CONCLUSION: A relation was found between cognitive impairment and functional disability which could not be explained entirely on the basis of psychiatric factors.

Activities of Daily Living↗
PubMed1998

Do peroxisome proliferating compounds pose a hepatocarcinogenic hazard to humans?

The purpose of the workshop "Do Peroxisome Proliferating Compounds Pose a Hepatocarcinogenic Hazard to Humans?" was to provide a review of the current state of the science on the relationship between peroxisome proliferation and hepatocarcinogenesis. There has been much debate regarding the mechanism by which peroxisome proliferators may induce liver tumors in rats and mice and whether these events occur in humans. A primary goal of the workshop was to determine where consensus might be reached regarding the interpretation of these data relative to the assessment of potential human risks. A core set of biochemical and cellular events has been identified in the rodent strains that are susceptible to the hepatocarcinogenic effects of peroxisome proliferators, including peroxisome proliferation, increases in fatty acyl-CoA oxidase levels, microsomal fatty acid oxidation, excess production of hydrogen peroxide, increases in rates of cell proliferation, and expression and activation of the alpha subtype of the peroxisome proliferator-activated receptor (PPAR-alpha). Such effects have not been identified clinically in liver biopsies from humans exposed to peroxisome proliferators or in in vitro studies with human hepatocytes, although PPAR-alpha is expressed at a very low level in human liver. Consensus was reached regarding the significant intermediary roles of cell proliferation and PPAR-alpha receptor expression and activation in tumor formation. Information considered necessary for characterizing a compound as a peroxisome proliferating hepatocarcinogen include hepatomegaly, enhanced cell proliferation, and an increase in hepatic acyl-CoA oxidase and/or palmitoyl-CoA oxidation levels. Given the lack of genotoxic potential of most peroxisome proliferating agents, and since humans appear likely to be refractive or insensitive to the tumorigenic response, risk assessments based on tumor data may not be appropriate. However, nontumor data on intermediate endpoints would provide appropriate toxicological endpoints to determine a point of departure such as the LED10 or NOAEL which would be the basis for a margin-of-exposure (MOE) risk assessment approach. Pertinent factors to be considered in the MOE evaluation would include the slope of the dose-response curve at the point of departure, the background exposure levels, and variability in the human response.

Animals↗
PubMed1998

Medical evaluation of Persian Gulf veterans with fatigue and/or chemical sensitivity.

The purpose of this study was to determine if Gulf War veterans with complaints of severe fatigue and/or chemical sensitivity (n = 72) fulfill case definitions for chronic fatigue syndrome (CFS) and/or multiple chemical sensitivity (MCS) and to compare the characteristics of those veterans who received a diagnosis of CFS (n = 24) to a group of non-veterans diagnosed with CFS (n = 95). Thirty-three veterans received a diagnosis of CFS with 14 having MCS concurrently; an additional six had MCS but did not fulfill a case definition for CFS. The group of fatigued veterans receiving a diagnosis of CFS was comprised of significantly fewer women and fewer Caucasians than the civilian group, and significantly fewer veterans reported a sudden onset to their illness. Veterans with CFS had a milder form of the illness than their civilian counterparts based on medical examiner assessment of the severity of the symptoms, reported days of reduced activity, and ability to work. Since CFS in veterans seems less severe than that seen in civilians, the prognosis for recovery of veterans with this disorder may be better.

Environmental Exposure↗
PubMed1997

Helplessness, self-efficacy, cognitive distortions, and depression in multiple sclerosis and spinal cord injury.

The aim of this study was to determine if learned helplessness, self-efficacy, and cognitive distortions would predict depression in a sample of 80 individuals with multiple sclerosis (MS) and 80 individuals with a spinal cord injury (SCI). As MS and SCI usually present with disparate disease courses and etiologies, a secondary objective was to determine if individuals with MS would exhibit greater levels of helplessness, cognitive distortions, and depression and lower levels of self-efficacy than those with SCI. Results indicated that helplessness and self-efficacy significantly predicted depression for both the MS and SCI groups after controlling for confounding variables. Cognitive distortions had no independent effect, indicating that cognitive distortions may have caused feelings of helplessness and low self-efficacy and, in this way, had indirect effects on depression. The MS group exhibited significantly greater levels of depression and helplessness and significantly lower levels of self-efficacy than the SCI group. It was hypothesized that it may have been the combination of an unpredictable course of disease activity and the possibility of being affected by MS in many different ways that produced greater feelings of depression, helplessness, and low self-efficacy in the MS group.

Adaptation, Psychological↗
PubMed1997

Neuropsychology of chronic fatigue syndrome: a critical review.

This article provides a comprehensive and critical review of the neuropsychological and related literature on chronic fatigue syndrome (CFS). Despite the methodological limitations observed in several studies, some consistent findings are noted. The most consistently documented neuropsychological impairments are in the areas of complex information processing speed and efficiency. General intellectual abilities and higher order cognitive skills are intact. Emotional factors influence subjective report of cognitive difficulty, whereas their effect on objective performance remains uncertain. Although the neuropathological processes underlying cognitive dysfunction in CFS are not yet known, preliminary evidence suggests the involvement of cerebral white matter. Directions for future research are outlined.

Fatigue Syndrome, Chronic↗
PubMed1997

The question of disproportionate impairments in visual and auditory information processing in multiple sclerosis.

The present study was conducted to investigate the hypothesis that subjects with MS have a disproportionate impairment in the phonological loop of working memory and whether such impairment is domain-specific. This was assessed by comparing performance in subjects with MS across both the visual (using the Paced Visual Serial Addition Test: PVSAT) and auditory (using the Paced Auditory Serial Addition Test: PASAT) domains. In addition, we assessed the role of processing speed in mediating performance deficits. The results showed that: (1) Although all subjects performed better on the PVSAT versus the PASAT, no disproportionate modality-specific differences were observed in the MS group relative to controls; and (2) the rate of decline across trials in the MS and healthy control groups did not differ on either the PVSAT or PASAT. Implications of the results are discussed within the context of a working memory model.

Adult↗
PubMed1997

Memory and executive functions in amnesic and non-amnesic patients with aneurysms of the anterior communicating artery.

Ruptured and repaired anterior communicating artery (ACoA) aneurysm can result in devastating impairments involving memory, executive function, confabulation and personality change. Importantly, traditional cerebral areas implicated in amnesia are not damaged, yet amnesia can still be manifested. While ACoA patients show normal visual-constructional skills (i.e. copy scores) on the Rey-Osterrieth complex figure test, recall is often impaired. What is unclear is whether impaired recall is attributable to problems in encoding, accelerated rates of forgetting, retrieval or some combination. To disentangle these issues, we examined 10 patients with ruptured aneurysms of the ACoA, using the Rey-organizational and extended memory procedure which uses an organizational procedure for enhancing immediate recall and provides added sensitivity by combining recall with non-recall measures (e.g. recognition, spatial discrimination and spatial assembly). The major findings were: (i) immediate recall in amnesics was improved by providing an organizational strategy; (ii) following the organization trials, amnesics and non-amnesics retained information to a comparable extent over a 30-min delay; (iii) two subgroups of amnesics emerged, those subjects impaired in acquisition and a second group with impaired retrieval; (iv) all subjects showed preserved memory on non-recall measures. These findings have important implications with respect to using organizational strategies in cognitive treatments and in using non-recall measures in improving the validity and reliability of patient assessment.

Adult↗