Rapid detection of enterotoxigenic clostridium perfringens by real-time fluorescence resonance energy transfer PCR.

Clostridium perfringens is one of the etiologic agents of gas gangrene that can occur when a wound is contaminated with soil. Type A C. perfringens can cause foodborne and nonfoodborne gastrointestinal illnesses due to an enterotoxin (CPE) produced by some strains during sporulation. We developed a quantitative real-time PCR assay based on fluorescence resonance energy transfer hybridization chemistry that targets the C. perfringens-specific phospholipase C (plc) gene and the enterotoxigenic gene (cpe) with the LightCycler and the Ruggedized Advanced Pathogen Identification Device (R.A.P.I.D.). The assay can detect as few as 20 copies of target sequences per PCR. The total assay time, from extraction to PCR analysis, is 90 min. This assay is rapid, sensitive, and specific and will allow direct detection of C. perfringens in water, food, and stool samples. It should prove helpful in investigating foodborne illnesses due to C. perfringens and can be used as a tool to ensure the safety of food and water supplies.

Evaluation of a real-time fluorescent PCR assay for rapid detection of Group B Streptococci in neonatal blood.

Streptococcus agalactiae (Group B Streptococcus: GBS) is the major causative agent of neonatal sepsis. Neonates at risk for GBS infections are empirically administered broad-spectrum antibiotics for at least 48 h pending blood culture results. A rapid assay to expedite detection of GBS would facilitate initiation of specific antibiotic therapy. Conversely, expeditious proof of absence of infection will avoid unnecessary antibiotic use. Using the LightCycler, we evaluated a hybridization probe polymerase chain reaction (PCR) assay to detect GBS-specific cfb gene target DNA sequence in blood specimens. Both sensitivity and specificity of the real-time PCR assay was 100%. The assay demonstrated 100% specificity when tested against 26 non-GBS bacteria. This method is capable of detecting as few as approximately 100 copies or 10 pg of GBS genomic DNA. This real-time PCR method is rapid, sensitive, and specific for the detection of GBS in neonatal blood samples and holds great promise in its utility in the diagnostic laboratory.

GABRA6 gene polymorphism and an attenuated stress response.

The glucocorticoid component of the stress response has been the subject of intense scientific scrutiny because of the wide ranging pathological consequences resulting from excess glucocorticoid exposure, including mood and anxiety disorders, and cognitive impairment. Exposure to stress activates the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic adrenomedullary system, which are regulated by neuronal pathways, including the inhibitory GABAergic (gamma-aminobutyric acid) system. Approximately 60% of the variance in glucocorticod levels may be attributable to genetic individual differences. In the present study, 56 healthy subjects underwent genotyping to determine the influence of the T1521C single nucleotide polymorphism (SNP) in the GABA(A)alpha6 receptor subunit gene (GABRA6) on the hormonal and autonomic responses to psychological stress induced by the Trier Social Stress Test (TSST). Adrenocorticotropin (ACTH), cortisol, diastolic blood pressure, and mean blood pressure responses to the TSST were significantly greater in subjects homozygous for the T allele or heterozygous compared to subjects homozygous for the C allele. Behavioral data was collected employing the Revised NEO Personality Inventory (NEO PI-R); subjects homozygous for the C allele scored significantly lower on the Extraversion factor compared to subjects homozygous for the T allele or heterozygous. These results suggest that the T1521C polymorphism in the GABRA6 gene is associated with specific personality characteristics as well as a marked attenuation in hormonal and blood pressure responses to psychological stress.

Opioids and alcoholism.

Although far from conclusive, evidence implicating the endogenous opioid system in the development and maintenance of alcoholism is growing. Currently available data suggest that ethanol increases opioid neurotransmission and that this activation is part of the mechanism responsible for its reinforcing effects. Findings from preclinical research indicate that ethanol consumption and ethanol-induced dopamine (DA) release are both reduced by opioid antagonists. Individual differences in endogenous opioid activity have been linked to inherited risks for alcoholism in studies comparing ethanol-preferring and nonpreferring rats, as well as in studies using targeted gene mutation (knockout) strategies. To a large extent, findings from human studies have paralleled those from the preclinical work. Persons who differ in family history of alcoholism have been shown to also differ in basal beta-endorphin activity, beta-endorphin response to alcohol, and subjective and HPA axis hormonal response to opioid antagonists. Findings from clinical trials indicate that opioid antagonists may reduce ethanol consumption in alcoholics, particularly in persons who have resumed drinking. Nevertheless, many questions remain unanswered about the use of opioid antagonists in alcoholism treatment and about the exact role of the opioid system in ethanol preference and reward. The progression of knowledge in this field suggests that many of these questions are imminently answerable, as our ability to characterize relationships between opioid activity and human behavior continues to develop. This paper summarizes both the progress that has been made and the gaps that remain in our understanding of the interactions between the endogenous opioid system and risk for alcoholism.

Erwinia chrysanthemi tolC is involved in resistance to antimicrobial plant chemicals and is essential for phytopathogenesis.

TolC is the outer-membrane component of several multidrug resistance (MDR) efflux pumps and plays an important role in the survival and virulence of many gram-negative bacterial animal pathogens. We have identified and characterized the outer-membrane protein-encoding gene tolC in the bacterial plant pathogen Erwinia chrysanthemi EC16. The gene was found to encode a 51-kDa protein with 70% identity to its Escherichia coli homologue. The E. chrysanthemi gene was able to functionally complement the E. coli tolC gene with respect to its role in MDR efflux pumps. A tolC mutant of E. chrysanthemi was found to be extremely sensitive to antimicrobial agents, including several plant-derived chemicals. This mutant was unable to grow in planta and its ability to cause plant tissue maceration was severely compromised. The tolC mutant was shown to be defective in the efflux of berberine, a model antimicrobial plant chemical. These results suggest that by conferring resistance to the antimicrobial compounds produced by plants, the E. chrysanthemi tolC plays an important role in the survival and colonization of the pathogen in plant tissue.

Evaluating the psychometric properties of a scale to measure medical students' career-related values.

PURPOSE: To develop and validate a survey instrument to measure medical students' career-related values. METHOD: A literature review yielded seven content domains that consistently correlated with medical students' career choices: biosocial orientation, bioscientific orientation, academic interest, prestige, income, desire to avoid role strain, and desire for role support. Item pools for the content domains were developed by examining previously published questionnaires and research and by interviewing health professionals, medical students, and premedical students. The instrument was tested in two phases. In phase 1, a 96-item questionnaire was mailed to all 847 students at the University of Minnesota School of Medicine. Results were submitted to item analysis and exploratory factor analysis. Construct validity of the questionnaire was assessed by (1) seeing if the seven scales correlated to one another in expected directions, (2) correlating students' survey responses with their self-reported interests in primary care, surgery, or radiology, and (3) seeing if anticipated sex differences were realized across the seven content domains. In phase 2, a random subgroup of 134 students was sent the final 46-item instrument twice to determine its short-term test-retest reliability. RESULTS: In phase 1, 670 students (79.2%) returned usable questionnaires. Seven scales corresponding to the content domains emerged from factor analyses. Cumulatively, they accounted for 43.9% of the variance in students' responses, and their internal consistency coefficients ranged from.71 to.87. All scales correlated with one another in the directions expected and, with two exceptions, at highly significant levels. High scores on bioscientific orientation, prestige, and income scales correlated positively with students' interest in surgery or radiology careers, but correlated negatively with their interest in primary care. High scores on biosocial orientation and avoid role strain scales correlated positively with students' interest in primary care, but correlated negatively with students' interest in surgery or radiology. Women had higher scores than did men on biosocial orientation, avoid role strain, and role support scales and lower scores on bioscientific orientation, academic interest, prestige, and income. Of these, all but the difference in role support scores were highly significant. In phase 2, 89 students (66%) returned questionnaires. Test-retest reliability for the seven scales ranged from.83 to.92. CONCLUSIONS: The seven scales pertaining to students' career-related values collectively demonstrated high internal consistency, short-term test-retest reliability, and evidence of construct validity. If predictive validity can be demonstrated in future research, the scales could have important applications for researchers, guidance counselors, and students, and they might also be useful to administrators who wish to identify students interested in primary care earlier in the students' training.

Predictors of individual differences in alprazolam self-medication.

Twenty-seven patients with generalized anxiety or panic disorder participated in a 6-week outpatient study. Participants received capsules containing either alprazolam or placebo and were free to choose between them for anxiety treatment. Measures of drug use included alprazolam preference, amount, and frequency of use. Alprazolam clearly was preferred over placebo; however, there were large between-subjects differences in the amount of medication used. A variety of demographic, drug history, personality, mood, and expectational variables were examined for correlation with medication use. Findings indicated that a substantial amount of variance in medication use could be explained by patients' intake characteristics. Findings also suggested that the tendency to consume capsules frequently may signal a greater risk factor for dependence than does drug preference in and of itself.

Relapse prevention treatment for cocaine dependence: group vs. individual format.

To investigate the role of treatment modality in relapse prevention treatment, 32 cocaine-dependent subjects were randomly assigned by cohorts to group-based relapse prevention (G-RP) or individually based RP (I-RP). The two RP formats were identical in content, consisting of 12 outpatient treatment sessions over a 2-month period immediately following hospitalization. The proportion of subjects providing cocaine-free urines at the end of RP treatment did not differ between formats; however, G-RP subjects reported using cocaine on significantly fewer days during treatment, and experiencing fewer cocaine-related problems than did I-RP subjects. Follow-up data collected at 12 and 24 weeks' posttreatment revealed no significant differences between RP formats on any cocaine-use outcome measures. Regardless of therapy format. RP treatment was related to statistically significant and sustained improvements in other areas of psychosocial functioning, including addiction severity, coping, and craving for cocaine. The overall findings suggest that the efficacy of relapse prevention training is not limited by therapy format.

Situational analysis of coping in substance-abusing patients.

A recently revised version of the Situational Competency Test (SCTDR), a tape-recorded role-play assessment procedure, was used to evaluate situational specificity of coping in hospitalized substance-abusing patients (N = 24). Responses to six types of high-risk situations were scored according to coping method used (active cognitive, active behavioral, avoidance, help-seeking) and objective response parameters (latency, duration, specification, compliance). Additionally, patterns of past drug use and self-efficacy were evaluated for situational variability and association with coping response measures. Findings revealed that the situational profiles for each of the four coping methods were distinct, and that each coping method was used differentially across high-risk situations. Objective scoring dimensions demonstrated patterns of situational specificity, for example, subjects' responses in situations involving unpleasant emotions were more delayed, shorter, and less specific than in other types of high-risk situations. Heavy past drug use and low self-efficacy were significantly related to latency in responding. These findings are consistent with previous studies in which substance abusers' coping was shown to be at least partially dependent on situational parameters.

General and specific locus of control in cocaine abusers.

Although the struggle for control has been widely recognized as a central feature of addiction, information about its role in the development and maintenance of addictive behavior is limited. This study compared general and specific locus of control in three groups of cocaine abusers: (a) hospitalized subjects with no prior treatment experience, (b) hospitalized subjects with prior treatment experience, and (c) recovering cocaine abusers. Results of initial analyses of variance revealed significant group differences on both general and specific scales. Scores of recovering cocaine abusers were more internal than those of hospitalized subjects. Differences on the general scale were not significant when age was controlled. No significant differences were noted between the two groups of hospitalized subjects, but scores of hospitalized cocaine abusers made an internal shift over the course of treatment. These findings support generalizability of models previously applied to alcoholics and suggest that internality is positively correlated with recovery.

Measurement of locus of control in cocaine abusers.

Although the course of recovery for cocaine abusers is particularly problematic, there has been little investigation of perceptions of control in this population. The purposes of this study were (1) to develop an instrument that would measure specific expectancies of control in cocaine abusers, and (2) to examine the relationship between specific and generalized expectancies of control in these subjects. Rotter's I-E scale and a modification of the Drinking-Related Locus of Control (DRIE) scale were administered to 40 cocaine abusers in their first week of treatment. The Modified DRIE scale demonstrated adequate internal consistency and satisfactory test-retest reliability in the sample. No significant correlation was found between the Modified DRIE scale and the I-E scale, probably because of the relatively small sample size. Further validation of the Modified DRIE scale is indicated.

Cocaine addiction: the hidden dimension.

There is growing awareness within the nursing profession that nurses need to expand their knowledge about addiction and develop expertise in providing care for substance abusing clients. This report presents a discussion about cocaine abuse that is focused on evolving knowledge about the physiology of addiction. Researchers have recently described cocaine-induced neurochemical changes in the brain that may form the underpinnings for the behavioral manifestations and symptomatology that have been associated with cocaine addiction. These neurochemical alterations are described at the cellular level, and treatment implications for nurses are presented.