Biomedical subjects

C R Carlson

Publications and source records attributed to C R Carlson.

At least 37 records · Page 2Linked to original sources

PubMed1996

Variable numbers of rRNA gene operons in Bacillus cereus strains.

Ribosomal RNA operon organisation was analysed in two Bacillus cereus strains of different chromosome size, ATCC 10987 (5.4 Mb) and F0837/76 (2.4 Mb). We estimated that there were twelve and nine copies of the rRNA operons in these two strains, respectively. In B. cereus ATCC 10987 six rRNA operons were less than 10 kb apart, while in B. cereus F0837/76 four rRNA operons were similarly clustered. The origin of replication was located in the vicinity of a rRNA operon in both strains.

Bacillus cereus↗

PubMed1996

Psychological coping with acute pain: an examination of the role of endogenous opioid mechanisms.

This study examined the relationship among endogenous opioids, Monitoring and Blunting coping styles, and acute pain responses. Fifty-eight male subjects underwent a 1-min pressure pain stimulus during two laboratory sessions. Subjects experienced this pain stimulus once under endogenous opioid blockade with naltrexone and once in a placebo condition. Blunting was found to be negatively correlated with pain ratings, but this relationship was significantly more prominent under opioid blockade. Results for coping behaviors subjects used to manage the experimental pain were generally consistent with the Blunting results, indicating that cognitive coping was related more strongly to decreased pain ratings and cardiovascular stress responsiveness under opioid blockade. Overall, the beneficial effects of Blunting and cognitive coping on pain responses did not depend upon endogenous opioids and, in fact, became stronger when opioid receptors were blocked. The relationship between endogenous opioids and coping appears to be dependent upon situational and stimulus characteristics.

Acute Disease↗

PubMed1996

Influence of a sympathomimetic amine on masticatory and trapezius pain/pressure thresholds and electromyographic levels.

OBJECTIVES: This study examined the influence of terbutaline, a beta-adrenergic sympathomimetic amine on pain/pressure thresholds in the index fingers and masseter and trapezius muscles and electromyographic activity in trapezii. STUDY DESIGN: In a randomized and double-blind controlled trial, 20 asymptomatic female subjects were assigned to receive either an injection of terbutaline or sterile water before collection of pain/pressure thresholds and electromyographic levels. Repeated analysis of variance and paired t tests were calculated to test for baseline and postinjection differences between groups. RESULTS: No significant baseline or postinjection group differences in pain/pressure thresholds or electromyographic were detected. CONCLUSIONS: beta-adrenergic sympathomimetic stimulation does not influence pain/pressure thresholds or electromyographic activity in the masselet and trapezius muscles or pain/pressure thresholds in the index fingers. These results suggest that development of painful muscle conditions is not caused by elevations of sympathetic activity.

Adolescent↗

PubMed1996

Relaxation training and opioid inhibition of blood pressure response to stress.

The present study was designed to determine the role of endogenous opioid mechanisms in the circulatory effects of relaxation training. Opioid mechanisms were assessed by examination of the effects of opioid receptor blockade with naltrexone on acute cardiovascular reactivity to laboratory stress before and after relaxation training. Thirty-two young men with mildly elevated casual arterial pressure were recruited for placebo-controlled naltrexone stress tests and relaxation training. The results indicated that relaxation training significantly reduced the diastolic pressure response to mental arithmetic stress. Opioid receptor blockade with naltrexone antagonized the effects of relaxation training. These findings suggest that some of the physiological effects of relaxation training are mediated by augmentation of inhibitory opioid mechanisms.

Adolescent↗

PubMed1996

The psychobiology of hostility: possible endogenous opioid mechanisms.

This study examined the role of endogenous opioids in the relation between hostility and cardiovascular stress responsiveness. Forty-six men completed the Cook-Medley Hostility Scale and experienced a laboratory pain stressor once under opioid blockade and once under placebo. Hostility scores were significantly related to the magnitude of change in cardiovascular reactivity/recovery resulting from opioid blockade. Low scorers on the Cynicism subscale displayed increases in heart rate (HR) reactivity under blockade relative to placebo, with reactivity decreases noted in high scorers. Low Hostile Affect scores were similarly associated with impaired diastolic blood pressure recovery under opioid blockade. HR recovery results were somewhat different, with high scorers on Aggressive Responding and the total Cook-Medley displaying improved HR recovery under opioid blockade, with no change noted in low scorers. These data provide preliminary support for the hypothesis that low hostile individuals rely on endogenous opioids for buffering cardiovascular stress responsiveness, but high hostiles do not.

Journal Article↗

PubMed1996

Emotional and physiologic responses to laboratory challenges: patients with temporomandibular disorders versus matched control subjects.

This study explored psychologic and physiologic factors differentiating patients with temporomandibular disorders (n = 23) from sex-, age-, and weight-matched asymptomatic control subjects. Each subject completed several standard psychologic questionnaires and then underwent two laboratory stressors (mental arithmetic and pressure-pain stimulation). Results indicated that patients with temporomandibular disorders had greater resting respiration rates and reported greater anxiety, sadness, and guilt relative to control subjects. In response to the math stressor, patients with temporomandibular disorders reacted with greater anger than did control subjects. There were no differences between patients with temporomandibular disorders and control subjects on pain measures or any other measured variable for the pressure-pain stimulation trial. In addition, there were no differences in electromyography levels between patients with temporomandibular disorders and control subjects. The results are discussed in terms of their implications for the etiology and treatment of this common and debilitating set of disorders.

Adult↗

PubMed1995

Physical and sexual abuse among orofacial pain patients: linkages with pain and psychologic distress.

This study examines the incidence of and the potential correlates of sexual and physical abuse among facial pain patients. An anonymous survey composed of standardized self-report measures of abuse, pain, and psychologic status was distributed to 120 adult facial pain patients following their initial evaluations. Forty-five questionnaires were returned by mail. In addition, 206 charts were randomly selected from a population of 520 new patients seen at the Orofacial Pain Center during the same time period that data from the anonymous survey were collected. Results of the anonymous survey indicated that 68.9% of the patients reported a history of abuse. Conversely, a chart review revealed that only 8.5% of the patients indicated a history of abuse on the clinic questionnaire. History of abuse was significantly related to greater pain severity, depression, psychologic distress, and various personality characteristics. Overall, this study indicates that the assessment of the history of abuse may be an important factor in the evaluation and treatment of facial pain.

Adaptation, Psychological↗

PubMed1994

Coping styles, opioid blockade, and cardiovascular response to stress.

We investigated the hypothesis that the effects of Monitoring and Blunting coping styles are mediated in part by endogenous opioids. Mean arterial pressure (MAP) and heart rate (HR) were measured in 39 males before, during, and after a mental arithmetic stressor. Each subject experienced the protocol once under opioid blockade (naltrexone) and once in a placebo condition, in counterbalanced order. Monitoring and Blunting were assessed using the Miller Behavioral Style Scale. High Blunting and high Monitoring were both associated with poorer MAP recovery under opioid blockade than in the placebo condition. Similar effects were noted for Blunting on the measure of HR. These results indicate that the coping styles of Monitoring and Blunting may be associated with enhanced opioid mediation of cardiovascular recovery from stress.

Adaptation, Psychological↗

PubMed1994

An unusual reaction to opioid blockade with naltrexone in a case of post-traumatic stress disorder.

An unusual behavioral and cardiovascular reaction was observed during opioid blockade with naltrexone in a 32-year-old male who met DSM III-R criteria for post-traumatic stress disorder (PTSD). As part of an ongoing placebo-controlled investigation of the effects of naltrexone on laboratory and ambulatory blood pressure reactivity, this participant reported experiencing feelings of rage, explosive behavior, and other unpleasant symptoms. When compared to all other subjects (N = 24), this individual showed significantly greater effects of naltrexone on blood pressure reactivity during the laboratory stressor. His ambulatory blood pressures, when compared to placebo, were significantly increased during the 24-hr period following naltrexone. The unusual behavioral and cardiovascular responses following ingestion of naltrexone suggest an important role for endogenous opioids in adjustment to stress in this case of PTSD.

Adult↗

PubMed1994

Stretch-based relaxation training.

This paper is a review of progressive relaxation training based on muscle stretching exercises. Stretch-based relaxation training is an alternative to traditional tense-release methods for teaching self-regulation of muscle activity. The rationale and basic procedures for stretch-based relaxation are presented, along with a review of research studies exploring the clinical efficacy of the techniques. Experimental evidence has demonstrated decreases in subjective measures of muscle tension and activation, as well as decreases in EMG activity at selected target muscle sites when stretch-based relaxation procedures are employed. The clinical application of stretch-based relaxation is presented and illustrated with a case study describing the use of these procedures to assist in the treatment of neck tension/pain and anxiety. Discussion centers on the potential role of stretch-based relaxation in the management of anxiety and musculoskeletal disorders.

Adult↗

PubMed1994

A small (2.4 Mb) Bacillus cereus chromosome corresponds to a conserved region of a larger (5.3 Mb) Bacillus cereus chromosome.

We have determined the sizes of the chromosomes of six Bacillus cereus strains (range 2.4-4.3 Mb) and constructed a physical map of the smallest B. cereus chromosome (2.4 Mb). This map was compared to those of the chromosomes of four B. cereus strains and one B. thuringiensis strain previously determined to be 5.4-6.3 Mb. Of more than 50 probes, 30 were localized to the same half of the larger B. cereus and B. thuringiensis chromosomes. All 30 were also present on the small chromosome. Twenty of the probes present on the other half of the larger chromosomes were either present on extrachromosomal DNA, or absent from the B. cereus strain carrying the small chromosome. We propose that the genome of B. cereus/B. thuringiensis has one constant part and another less stable part which is more easily mobilized into other genetic elements. This part of the genome is localized to one region of the chromosome and may be subject to deletions or more frequent relocations between the chromosome and episomal elements of varying sizes up to the order of megabases.

Bacillus cereus↗

PubMed1994

Genotypic Diversity among Bacillus cereus and Bacillus thuringiensis Strains.

Twenty-four strains of Bacillus cereus were analyzed by pulsed-field gel electrophoresis (PFGE) and compared with 12 Bacillus thuringiensis strains. In addition, the 36 strains were examined for variation in 15 chromosomal genes encoding enzymes (by multilocus enzyme electrophoresis [MEE]). The genome of each strain had a distinct NotI restriction enzyme digestion profile by PFGE, and the 36 strains could be assigned to 27 multilocus genotypes by MEE. However, neither PFGE nor MEE analysis could distinguish between the two species. Two of the B. cereus strains contained extrachromosomal DNA that hybridized to a cryIA insecticidal toxin probe, and seven strains contained DNA with homology to a Tn4430 transposon probe derived from B. thuringiensis. The results strongly indicate that B. cereus and B. thuringiensis should be regarded as one species.

Journal Article↗

PubMed1993

Efficacy of abbreviated progressive muscle relaxation training: a quantitative review of behavioral medicine research.

A quantitative review was undertaken of recent research in which abbreviated progressive muscle relaxation training (APRT) was used as an intervention for psychophysiological and stress-related disorders. The strength of association between APRT and outcome measures was calculated for 29 experiments published after 1980. The average effect size across all experiments was moderate (r = .40). Moreover, for experiments that included a follow-up assessment, a similar effect size was noted at the first follow-up (r = .43). Additionally, experiments that used a prospective design (i.e., analyzed change) detected a stronger effect for APRT than those that used a cross-sectional design (i.e., compared groups). APRT was most strongly associated with improvement in experiments that delivered APRT on an individual basis and provided recipients with training tapes. Moreover, the treatment duration and number of sessions positively influenced the strength of association.

Arousal↗

PubMed1993

A complete physical map of a Bacillus thuringiensis chromosome.

Bacillus thuringiensis is the source of the most widely used biological pesticide, through its production of insecticidal toxins. The toxin genes are often localized on plasmids. We have constructed a physical map of a Bacillus thuringiensis chromosome by aligning 16 fragments obtained by digestion with the restriction enzyme NotI. The fragments ranged from 15 to 1,350 kb. The size of the chromosome was 5.4 Mb. The NotI DNA fingerprint patterns of 12 different B. thuringiensis strains showed marked variation. The cryIA-type toxin gene was present on the chromosome in four strains, was extrachromosomal in four strains, and was both chromosomal and extrachromosomal in two strains. A Tn4430 transposon probe hybridized to 5 of the 10 cryIA-positive chromosomal fragments, while cryIA and the transposon often hybridized to different extrachromosomal bands. Ten of the strains were hemolytic when grown on agar plates containing human erythrocytes. Nine of the strains were positive when assayed for the presence of Bacillus cereus enterotoxin. We conclude that B. thuringiensis is very closely related to B. cereus and that the distinction between B. cereus and B. thuringiensis should be reconsidered.

Bacillus thuringiensis↗

PubMed1993

Comparison of psychologic and physiologic functioning between patients with masticatory muscle pain and matched controls.

This study explored the physiologic and psychologic distinctions between masticatory muscle pain patients and age and sex-matched normal controls. Subjects completed several standardized psychologic tests. They then underwent a laboratory stress profile evaluation to obtain physiologic measures (EMG, heart rate, systolic and diastolic blood pressure) under conditions of rest, mental stress, and relaxation. The pain patients reported greater anxiety, especially cognitive symptoms, and feelings of muscle tension than did the controls. Under stress, pain patients had higher heart rates and systolic blood pressure than the controls. Electromyogram activity in the masseter regions was not significantly different between the pain and control group. The results are discussed in terms of the likely mechanisms that might account for the observed differences between masticatory pain patients and normal subjects.

Adult↗

PubMed1992

Predisposing psychological factors in the development of reflex sympathetic dystrophy. A review of the empirical evidence.

OBJECTIVE: To examine the literature for evidence that psychological factors predispose certain individuals to development of reflex sympathetic dystrophy (RSD). DATA SOURCES: English-language journal articles that described psychological data on patients diagnosed with RSD, identified through Medline search and bibliography reviews. STUDY SELECTION: All studies reporting data on psychological factors in adult, adolescent, or child patients with RSD were included. DATA EXTRACTION: We extracted data regarding psychological factors in patients with RSD and assessed validity of these studies through evaluation against seven basic research criteria. DATA SYNTHESIS: Of the 20 articles reviewed, 15 reported the presence of depression, anxiety, and/or life stress in patients with RSD. However, the methodological quality of these studies was generally poor, with most meeting three or less of the seven validity criteria. In particular, the absence of prospective designs restricts conclusions concerning whether psychological factors are etiologically related to RSD. CONCLUSIONS: The data reviewed are consistent with a theoretical model in which depression, anxiety, or life stressors may influence development of RSD through their effects on alpha-adrenergic activity. However, conclusions regarding etiological significance of these factors are not possible due to the dearth of high-quality studies. Suggestions for prospective research are described.

Humans↗

PubMed1992

Physical maps of the genomes of three Bacillus cereus strains.

NotI restriction maps of the chromosomes from Bacillus cereus ATCC 10876, ATCC 11778, and the B. cereus type strain ATCC 14579 have been established and compared with the previously established map of B. cereus ATCC 10987. Between 10 and 14 NotI fragments were observed, ranging from 15 to 1,300 kb, in digests of DNA from the various strains. The sizes of the genomes varied between 5.4 and 6.3 Mb. The maps were constructed by hybridization of 42 random probes, prepared from B. cereus ATCC 10987 libraries, to fragments from partial and complete NotI digests, separated by pulsed-field gel electrophoresis. Nine probes were specific for ATCC 10987 only. Probes for five B. subtilis and five B. cereus genes were also used. The NotI restriction fragment patterns of the four strains were strikingly different.

Bacillus cereus↗

PubMed1991

Negative side effects of self-regulation training: relaxation and the role of the professional in service delivery.

Procedures used for relaxation training can resolve or precipitate dysfunction in patients undergoing self-regulation treatments. The present article discusses the role of the clinician in administering relaxation training via thermal biofeedback and coping with unforeseen negative effects of treatment. A case illustration involving the biobehavioral treatment of chest pain is presented and discussed to remind the reader of the significance of the therapist's role in helping tailor treatment programs to unique responses of the individual patient. The case highlights the value of thorough case management and clinical formulation in the successful resolution of relaxation-induced leg pain.

Biofeedback, Psychology↗