Perceived relevance mediates the relationship between professional identity and attitudes towards interprofessional education in first-year university students.

The strength of health science students' identification with their chosen profession is associated with their attitudes towards interprofessional education (IPE). However, little is known about the factors that might mediate this relationship. In this article, we examine the relationships between professional identification, communication and teamwork skills, perceived relevance of IPE, and positive and negative attitudes towards IPE. A sample of 444 first-year university students from 25 health science professions enrolled in a first-year interprofessional program participated in this research by completing a questionnaire. Data were analysed using path analysis. Positive IPE attitudes were more strongly endorsed than negative IPE attitudes. Perceived relevance of IPE to future careers was the strongest predictor of both positive and negative attitudes to IPE, and fully mediated the effect of professional identity. Self-reported communication and teamwork skills were a significant negative predictor of negative attitudes to IPE only, and the effect was not mediated by perceived relevance. These findings indicate that IPE may be particularly challenging for students who do not have confidence in their abilities to communicate and work effectively in teams. Building these skills through alternative communication technologies may decrease negative attitudes. In order to maintain or increase positive attitudes towards IPE in introductory programs that span professions, the curriculum needs to be designed to demonstrate relevance to the future careers of participating students.

Quantitative magnetic resonance imaging in a naturally occurring canine model of spinal cord injury.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To analyze magnetic resonance imaging (MRI) evaluator agreement in dogs with spinal cord injury (SCI) caused by intervertebral disk herniation (IVDH) using semiautomated and manual lesion segmentation and to analyze the associations between MRI and functional outcome. SETTING: United States of America. METHODS: T2-weighted MRIs from dogs with SCI resulting from thoracolumbar IVDH were identified from a database. Evaluators categorized MRIs on the basis of the presence or absence of a T2-hyperintense spinal cord lesion in axial and sagittal images. A semiautomated segmentation algorithm was developed and used to estimate the lesion volume. Agreement between evaluators and between semiautomated and manual segmentation was analyzed. The relationships of qualitative and quantitative MRIs with behavioral functional outcome were analyzed. RESULTS: Axial images more commonly depicted lesions compared with sagittal images. Lesions in axial images had more consistent associations with functional outcome compared with sagittal images. There was imperfect qualitative agreement, and lesion volume estimation was imprecise. However, there was improved precision using semiautomated segmentation compared with manual segmentation. CONCLUSION: Lesion volume estimation in dogs with naturally occurring SCI caused by IVDH is challenging, and axial images have important advantages compared with sagittal images. The semiautomated segmentation algorithm described herein shows promise but may require further refinement.

Discontinuation of clozapine: a 15-year naturalistic retrospective study of 320 patients.

OBJECTIVE: Clozapine is underutilized in the management of treatment-resistant schizophrenia. To understand contributing factors, we analyzed the frequency and causes of clozapine discontinuations that occurred over a 15-year period in a clinical setting. METHOD: Data were extracted from computerized records and from mandatory termination reports for discontinuation events 1993-2007. The reasons for termination were analyzed. RESULTS: Over half of the patients (n = 183/320; 57%) had at least one discontinuation (median time 609 days). The two most common causes for discontinuation were non-adherence (35%) and side-effects (28%). Hematological side-effects accounted for 45% of all side-effect associated discontinuations; most such patients remained eligible for clozapine treatment, and a significant fraction remained on clozapine after rechallenge. Central nervous system side-effects accounted for 35% of side-effect induced discontinuations. General factors significantly associated with discontinuation were African American race, older age at initiation of clozapine and less improvement in psychiatric symptoms. CONCLUSION: In addition to anticipating and addressing causes of non-adherence, psychiatrists should consider clozapine rechallenge in eligible patients and implement measures to mitigate clozapine-associated sedation, seizures, and other side-effects. Future studies should particularly address why African American and older patients may be more likely to discontinue clozapine.

Reliability and validity of the parent efficacy for child healthy weight behaviour (PECHWB) scale.

BACKGROUND: Interventions for childhood overweight and obesity that target parents as the agents of change by increasing parent self-efficacy for facilitating their child's healthy weight behaviours require a reliable and valid tool to measure parent self-efficacy before and after interventions. Nelson and Davis developed the Parent Efficacy for Child Healthy Weight Behaviour (PECHWB) scale with good preliminary evidence of reliability and validity. The aim of this research was to provide further psychometric evidence from an independent Australian sample. METHODS: Data were provided by a convenience sample of 261 primary caregivers of children aged 4-17 years via an online survey. PECHWB scores were correlated with scores on other self-report measures of parenting efficacy and 2- to 4-week test-retest reliability of the PECHWB was assessed. RESULTS: The results of the study confirmed the four-factor structure of the PECHWB (Fat and Sugar, Sedentary Behaviours, Physical Activity, and Fruit and Vegetables) and provided strong evidence of internal consistency and test-retest reliability, as well as good evidence of convergent validity. CONCLUSION: Future research should investigate the properties of the PECHWB in a sample of parents of overweight or obese children, including measures of child weight and actual child healthy weight behaviours to provide evidence of the concurrent and predictive validity of PECHWB scores.

Thioredoxin-interacting protein (txnip) is a glucocorticoid-regulated primary response gene involved in mediating glucocorticoid-induced apoptosis.

Glucocorticoid hormones induce apoptosis in lymphoid cells. This process is transcriptionally regulated and requires de novo RNA/protein synthesis. However, the full spectrum of glucocorticoid-regulated genes mediating this cell death process is unknown. Through gene expression profiling we discovered that the expression of thioredoxin-intereacting protein (txnip) mRNA is significantly induced by the glucocorticoid hormone dexamethasone not only in the murine T-cell lymphoma line WEHI7.2, but also in normal mouse thymocytes. This result was confirmed by Northern blot analysis in multiple models of dexamethasone-induced apoptosis. The induction of txnip mRNA by dexamethasone appears to be mediated through the glucocorticoid receptor as it is blocked in the presence of RU486, a glucocorticoid receptor antagonist. Deletion and mutation analysis of the txnip promoter identified a functional glucocorticoid response element in the txnip promoter. Reporter assays demonstrated that this glucocorticoid response element was necessary and sufficient for induction of txnip by dexamethasone. Expression of a GFP-TXNIP fusion protein was sufficient to induce apoptosis in WEHI7.2 cells, and repression of endogenous txnip by RNA interference inhibited dexamethasone-induced apoptosis in WEHI7.2 cells. Together, these findings indicate that txnip is a novel glucocorticoid-induced primary target gene involved in mediating glucocorticoid-induced apoptosis.

Effects of nullisomic chromosome deficiencies on conjugation events in Tetrahymena thermophila: insufficiency of the parental macronucleus to direct postzygotic development.

Conjugation fails postzygotically after mating of Tetrahymena cells that have wild-type parental macronuclei but harbor noncomplementing nullisomic parental germline deficiencies. Failures begin shortly after formation of the new macronuclear precursor (anlage) and completion of the first step in elimination of the parental macronucleus (pycnosis). Conjugants fail to complete pair separation, to eliminate one new micronucleus, and to amplify anlage DNA, and they eventually die. Some deficiencies block resorption of the pycnotic parental macronucleus, but we find no evidence for its regeneration. Some deficiencies cause aberrant anlage DNA loss. Those that do not cause DNA loss are epistatic to those that do, indicating that normal anlage development requires the dependent function of at least two types of genes. The possibility that these genes are involved in developmentally regulated anlage DNA rearrangements is discussed. Each observed conjugation defect indicates insufficiency of the parental macronucleus to direct postzygotic development and can be explained by the deficiency of essential conjugation genes that are expressed from the anlage. The failure of nullisomic conjugants to complete pair separation indicates a requirement for gene products, expressed from the early anlage or its precursors, soon after anlage first differentiate.

Antimycobacterial activity of substituted isosteres of pyridine- and pyrazinecarboxylic acids.

Pyrazines and pyridines substituted with alkylated tetrazoles, esterified vinylogous carboxylic acids, and ketosulfides were synthesized as precursors of antimycobacterial agents which, after penetration of the mycobacterial cell wall, could be biotransformed by esterases or peroxidase-catalases. The expected products are tetrazoles, a vinylogous carboxylic acid, and CH-acidic ketosulfoxides, isosteres of pyrazinoic and nicotinic acids, which should inhibit mycobacterial growth when released inside the bacterial cell. The growth inhibitory activity of the synthesized compounds against the H37Rv strain of Mycobacterium tuberculosis was determined to assess the viability of this concept. It was shown that all of the compounds designed as lipophilic precursors were more active than the unmodified polar isosteres of pyrazinoic and nicotinic acids.

DNA polymerases as engines for biotechnology.

This review examines the DNA polymerases, a class of enzymes that has been an essential tool for molecular biology research. Several families of DNA polymerases have been defined based on amino acid sequence comparisons, and new enzymes are continually being discovered, driving the expansion of the current classifications. Structural similarities among the enzymes are examined, as well as the functions of the various subunits and enzyme domains. The natural variety of polymerase activities has been harnessed for applications such as amplification, labeling, and detection of DNA sequences. In addition, enhancements to DNA polymerases by genetic engineering will be described, such as enzymes specifically designed for DNA sequencing by improving the incorporation of dideoxynucleotide terminators. Reverse transcription, the ability to use RNA as a template for DNA synthesis, is described for the application of making cDNA. We believe that new and unanticipated applications will emerge as new polymerases and mutated polymerases are created and characterized.

Thermo Sequenase DNA polymerase and T. acidophilum pyrophosphatase: new thermostable enzymes for DNA sequencing.

A combination of thermostable enzymes has been developed that produces higher quality cycle sequences. Thermo Sequenase DNA polymerase is a thermostable enzyme engineered to catalyze the incorporation of ddNTPs with an efficiency several thousandfold better than other thermostable DNA polymerases. Since the enzyme also catalyzes pyrophosphorolysis at dideoxy termini, a thermostable inorganic pyrophosphatase is needed to remove the pyrophosphate produced during sequencing reactions. Thermoplasma acidophilum inorganic pyrophosphatase (TAP) is thermostable and effective for converting pyrophosphate to orthophosphate. The use of the combination of Thermo Sequenase polymerase and TAP for cycle sequencing yields sequence data with uniform band intensities, allowing the determination of longer, more accurate sequence reads. Uniform band intensities also facilitate interpretation of sequence anomalies and the presence of mixed templates. Sequencing PCR products of DNA amplified from heterozygous diploid individuals results in signals of equal intensity from each allele.

Oral contraceptive use and hemodynamic, lipid, and fibrinogen responses to smoking and stress in women.

The effects of acute smoking and oral contraceptive (OC) use on cardiovascular, lipid, and fibrinogen stress responses were examined in 52 female smokers and nonsmokers, half of whom were using OCs. Women smoked or sham-smoked a cigarette and then performed 2 stressful tasks. Stress elicited increases in total and low-density lipoprotein cholesterol, and in triglycerides among women who smoked, and in fibrinogen among all women. Smokers who used OCs had greater blood pressure increases to smoking and to stress than did smokers who did not use OCs. OC use was also associated with enhanced total peripheral resistance stress responses among women who smoked and cardiac output stress responses among women who sham-smoked. Results suggest that OC use moderates cardiovascular reactivity in smokers but not nonsmokers, enhancing vascular responsivity to smoking combined with stress and myocardial responsivity to stress alone.

PIP: This study examined the association between the use of oral contraceptives (OCs) and the hemodynamic stress responses of nonsmokers, abstinent and recent smokers, and the effects of acute smoking and OC use on stress-related changes in atherogenic lipid and fibrinogen levels. The study comprised 52 female smokers and nonsmokers, with half using OCs. Women were asked to perform two stressful activities after smoking or sham-smoking. An increase in total and low-density lipoprotein cholesterol and triglycerides was observed among women who smoked, and in fibrinogen among all women. Systolic Blood Pressure was higher among women who smoked and used OCs, while higher diastolic blood pressure was found among women who smoked regardless of OC use. The use of OCs resulted in an increase in the total peripheral resistance stress responses among female smokers and increased cardiac output among women who sham-smoked. Results suggest that cardiovascular reactivity is moderated by OC use in smokers but not in nonsmokers, while vascular responsivity is enhanced when combined with stress.

Association of negative and positive social ties with fibrinogen levels in young women.

The associations between positive and negative aspects of social relationships and fibrinogen, a risk factor for coronary heart disease (CHD), were examined in young, healthy women recruited from the community (n = 46) and from a college campus (n = 42). For community women, the perception that individuals in their social networks frequently undermined them was related to higher fibrinogen, independent of perceived frequency of support. For college women, fibrinogen was elevated among women with frequent undermining only when they also reported infrequent support. After controlling for other risk factors, the associations between social ties and fibrinogen remained significant in both samples. These results indicate that positive and negative social ties are associated with fibrinogen levels and suggest that social relationships may affect CHD risk in part through their influence on fibrinogen.

Cigarette smoking and oral contraceptive use influence women's lipid, lipoprotein, and cardiovascular responses during stress.

Investigated the effects of behavioral stress and smoking cigarettes on the lipid, lipoprotein, neuroendocrine, and cardiovascular responses of female smokers who either used or did not use oral contraceptives (OC). Thirty-five healthy female smokers (20 of whom used OC) relaxed, smoked, or sham smoked and then prepared, delivered, and reviewed a speech presented in front of a video camera. Results show that behavioral stress increased total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglyceride, and free fatty acid levels, with significant increases in cholesterol, LDL-C, and free fatty acids apparent only among women who smoked during the session. In addition, OC users exhibited larger increases in triglyceride and blood pressure responses during stress than did nonusers whether or not they smoked during the protocol. Possible physiological mechanisms for each of the effects, as well as implications of the findings for understanding epidemiological associations among OC use, smoking, and coronary heart disease in women are discussed.

PIP: 35 females smokers, of whom 20 had taken combined oral contraceptives for 6 months or more, participated in a study of the effect of smoking and social stress on cardiovascular response, catecholamines and lipoproteins. The stress consisted of giving a 4-minute videotaped extemporaneous speech, after smoking 1 cigarette or sham-smoking. Testing was done in the luteal phase or on Days 15-22 of a pill cycle, after an overnight fast without smoking. Neither smoking nor stress affected catecholamines. Blood pressures and heart rate increased significantly during speech preparation, delivery and review in all subjects; and during inhalation in smoking women. Oral contraceptive users had higher baseline levels of total cholesterol and triglycerides, and their cholesterol and triglycerides increased more than did nonusers during the speech, triglycerides significantly so. Pill users also had higher systolic and diastolic blood pressure increases during delivery of the speech than did nonusers. This study corroborates previous reports that smoking increases cardiovascular responses additively to stress, and is the first report higher increases in triglycerides and cholesterol during stress in pill users.

Does the gender relevance of the stressor influence sex differences in psychophysiological responses?

Sex differences in psychophysiological responses to stress may be important to understanding sex differences in risk for coronary heart disease. This investigation tested the hypothesis that the gender relevance of the stressor influences the extent of sex differences in cardiovascular, neuroendocrine, and lipid responses during stress. Participants performed two tasks that were described as masculine oriented, feminine oriented, or not gender relevant. Although these descriptions influenced the participants' perceptions of the tasks, they did not influence the extent of sex differences in physiological responses in a manner consistent with the study hypothesis. Future directions for research are discussed regarding sex differences in psychophysiological responses.

Are job characteristics related to fibrinogen levels in middle-aged women?

This study examined whether employment status or job characteristics thought to be stressful were related to fibrinogen level in a sample of 161 healthy middle-aged women. Employed women had higher fibrinogen levels than did nonemployed women. Moreover, among employed women, those who perceived high levels of job stress or low support from their bosses had elevated fibrinogen, independent of menopausal status. Perception of low support from one's boss was related to higher fibrinogen levels only among premenopausal women or postmenopausal women who were not using hormone replacement therapy. These results are consistent with the notion that stress associated with some job characteristics influences levels of fibrinogen in women.

Body fat distribution and hemodynamic stress responses in premenopausal obese women: a preliminary study.

To examine the relationship between body fat distribution and hemodynamic stress responses, cardiovascular responses to a speech task and a forehead cold pressor task were evaluated with 24 premenopausal women classified a priori as either centrally or peripherally obese. Results showed that women with central adiposity exhibited greater stress-related increases in diastolic blood pressure and total peripheral resistance, whereas women with peripheral adiposity exhibited greater stress-related increases in cardiac output. Depression, self-consciousness, hostility, and mood scores did not explain significant variance in the stress response differences between regional adiposity groups. The findings suggest that central adiposity may increase the risk of cardiovascular disease in women at least in part by enhancing vascular responses to stress.

Is life more difficult on Mars or Venus? A meta-analytic review of sex differences in major and minor life events.

We conducted a meta-analysis of studies examining sex differences in reported levels of stress, considering the impact of: (a) the age and representativeness of sample participants, (b) whether life events were weighted or unweighted by participants for impact or severity, (c) the major versus minor nature of the stress, and (d) the life domain of the stressor. Overall, the meta-analysis of 119 studies including 83,559 participants found that females were exposed to more stress than were males (d=.123, r=.061). However, there was considerable heterogeneity among studies, with greater effect sizes associated with: (a) life events weighted by participants for impact, (b) adolescents compared to both younger and older samples, (c) major life stressors compared to minor stressors, and (d) interpersonal relationship stressors compared to work stressors. In none of the subgroup analyses did males experience considerably more stress than females. Evaluation of a subsample of 39 studies that examined gender differences in psychological symptoms revealed that females reported more symptoms of depression, anxiety, and psychosomatic problems (d=.282, r=.139) and that the sex difference in reports of psychological symptoms accounted for approximately 4% of the variance in the sex differences in reports of stress. Possible explanations for the observed patterning of effects are discussed, as are recommendations for further research.

Effect of prior nicotine treatment on drug induced changes in serum LH concentrations in rats.

The effect of daily injections of nicotine on drug induced changes in LH secretion was investigated in male rats. Daily administration of nicotine for 7 days resulted in decreased basal serum LH concentrations. Nicotine treatment blocked naloxone induced LH release and reduced LHRH induced increases in serum LH. Clonidine induced increases in serum LH were not altered by nicotine treatment and haloperidol treatment did not alter nicotine induced decreases in serum LH. In an acute study nicotine blocked LH secretion induced by the long acting opioid antagonist naltrexone. Collectively these results indicate that opioidergic neurons are involved in the reduction in serum LH that occurs following nicotine. They also indicate that chronic nicotine treatment can reduce the pituitary gland response to LHRH.

Do gender-relevant characteristics determine cardiovascular reactivity? Match versus mismatch of traits and situation.

This study tested the hypothesis that individuals exhibit heightened cardiovascular reactivity to a challenging task that is consistent vs. inconsistent with their gender-relevant attributes. In all, 82 men and women categorized as either highly instrumental or expressive engaged in an interpersonal task designed to tap instrumental or expressive characteristics. Results failed to confirm the hypothesis. Expressive individuals tended to exhibit larger increases in systolic blood pressure during an instrumental, relative to an expressive, interaction. Instrumental individuals tended to show larger increases in diastolic blood pressure during an expressive, relative to an instrumental, interaction. These results are consistent with the post hoc interpretation that environmental demands that fall outside of one's perceived areas of competency may result in exaggerated cardiovascular responsivity.

Quantitative sacroiliac scintigraphy. The effect of method of selection of region of interest.

Various authors have advocated quantitative methods of evaluating bone scintigrams to detect sacroiliitis, while others have not found them useful. Many explanations for this disagreement have been offered, including differences in the method of case selection, ethnicity, gender, and previous drug therapy. It would appear that one of the most important impediments to consistent results is the variability of selecting sacroiliac joint and reference regions of interest (ROIs). The effect of ROI selection would seem particularly important because of the normal variability of radioactivity within the reference regions that have been used (sacrum, spine, iliac wing) and the inhomogeneity of activity in the SI joints. We have investigated the effect of ROI selection, using five different methods representative of, though not necessarily identical to, those found in the literature. Each method produced unique mean indices that were different for patients with ankylosing spondylitis (AS) and controls. The method of Ayres (19) proved superior (largest mean difference, smallest variance), but none worked well as a diagnostic tool because of substantial overlap of the distributions of indices of patient and control groups. We conclude that ROI selection is important in determining results, and quantitative scintigraphic methods in general are not effective tools for diagnosing AS. Among the possible factors limiting success, difficulty in selecting a stable reference area seems of particular importance.