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.

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.

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 Not I 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 Tn 4430 transposon probe derived from B. thuringiensis. The results strongly indicate that B. cereus and B. thuringiensis should be regarded as one species.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Muscle stretching as an alternative relaxation training procedure

The purpose of this program of research was to explore the use of muscle stretching procedures in relaxation training with a clinical population. In the first controlled study, stretching exercises for four muscle groups (obicularis occuli, sternocleidomastoid/trapezius, triceps/pectoralis major, and forearm/wrist flexors) were prepared. A group of people using these procedures (SR, N = 8) was compared to a group using the Bernstein and Borkovec (1973) tense-release (TR; N = 8) techniques for those same muscle groups, as well as compared to an appropriate group of controls (WL; N = 8). Assessment of physiological (multi-site EMG) and subjective (emotions, muscle tension, and self-efficacy) responses showed that persons in the SR displayed less sadness, less self-reported muscle tension at four sites, and less EMG activity on the r.masseter than persons in the TR group. In the second study, 15 subjects were administered an expanded version of the SR relaxation procedures. Results showed that all subjects reported significant decreases in self-reported levels of muscle tension; muscle tension responders showed lowered trapezius EMG and respiration rates and cardiovascular responders showed lowered diastolic blood pressure. The results are discussed in terms of the utility of relaxation procedures based primarily on muscle stretching exercises for lowering subjective and objective states of arousal.

Relaxation training through muscle stretching procedures: a pilot case

The present paper introduces a relaxation procedure based upon muscle stretching exercises. Traditional progressive relaxation training starts from muscle tensing exercises to teach voluntary control of muscle tension, but the literature shows widely varying results. An alternative method of relaxation training starts from muscle stretching exercises. Muscle stretching provides sensation contrasts for learning relaxation in addition to fostering relaxation through the stretching of muscles. The present report documents the rationale for the procedure and presents data from a clinical case study, including six months' follow-up, in support of its efficacy.

Theory of shape-invariant imaging systems

The human visual system exhibits two properties that may be useful in other pattern-recognition systems: images do not change their shape with changes in image size and resolution declines rapidly with distance from the center of fixation. We show here that, in general, shape invariance requires inhomogeneous resolution over image space in a manner similar to that of the human visual system. Thus shape-invariant systems must process less information when compared with uniform-resolution systems. Although shape-invariant systems can be rotationally invariant, they cannot, in general, be translationally invariant. The properties of shape-invariant systems are explored in the spatial-frequency domain using a modified Fourier transform called a scaled transform. The features of scaled transforms are discussed and their behavior illustrated in the image domain by using them to filter various images, including the dot, the line, and the edge. It is shown that the filtered profile of an edge is preserved when it passes through the origin of a scaled transform. This result suggests that scaled transforms may be useful in edge-detection algorithms.

An assessment of the treatment needs of Vietnam-era veterans

A needs assessment was conducted to determine the existence and extent of differences between Vietnam-era veterans and other veterans residing within the catchment area of the Northport Veterans Administration Medical Center. The results of a questionnaire completed by 486 veterans indicated that, compared with World War II and Korean War veterans, a greater percentage of Vietnam-era veterans reported experiencing the symptoms of posttraumatic stress disorder. They also reported more situational adjustment problems. A great number of Vietnam-era veterans expressed a need for psychotherapy and anger-control therapy, and they generally preferred to be treated with other Vietnam-era veterans who have had similar combat experience.

Data-based versus symptomatic formulation of treatment: the case of a dependent personality

A 48-year-old female presented anxiety and avoidances following diagnosis of her daughter as diabetic. A comprehensive formulation of the case seemed unobtainable. Symptomatic treatment was thus initiated which led to improvement then relapse. Subsequent clinical observation led to a new formulation, namely, anxiety about independent decision making. This hypothesis was assessed. The patient was found to be excessively reliant on others and deficient in autonomous behavior. Accordingly, treatment was aimed at modifying anxiety about independent decision making, and this proved successful. Improvements maintained at an 11-month follow-up. The implications of this case for clinical practice are discussed.

Visual illusions without low spatial frequencies

It has been suggested that many geometrical illusions may be caused by the lower spatial frequencies in the Fourier spectra of these images. We have tested this hypothesis by constructing classical illusory figures out of a new dot stimulus, which is free of visible low spatial frequencies. In every case, not only does the illusion persist, but for the Müller-Lyer figures, which were measured quantitatively, the illusion magnitude is not significantly changed. We conclude that geometrical illusions are not primarily a consequence of low spatial frequencies in the illusory figures.

Spatially inhomogeneous scaled transforms for vision and pattern recognition

Scale invariance and data compression are two desirable attributes for spatial transforms to be used for pattern recognition. We have found that the requirement of a form of scale invariance leads to a natural reduction in the information to be processed. Such scaled transforms exhibit spatial inhomogeneity similar to that of the human visual system. That is, scaled transforms provide a global view of low resolution while maintaining a detailed view of the image at the transform center (which can be moved to points of interest). Like the visual system, scaled transforms can have rotational invariance, but, in general, translational invariance is lost. The conventional Fourier transform is a limiting case of the general class of scaled transforms.