A taxometric analysis of health anxiety

BACKGROUND

A long-standing issue in the health anxiety literature is the extent to which health anxiety is a dimensional or a categorical construct. This study explores this question directly using taxometric procedures.

METHOD

Seven hundred and eleven working adults completed an index of health anxiety [the Whiteley Index (WI)] and indicated their current health status. Data from those who were currently healthy (n=501) and receiving no medical treatment were examined using three taxometric procedures: mean above minus below a cut (MAMBAC), maximum eigenvalue (MAXEIGEN) and L-mode factor analysis (L-MODE).

RESULTS

Graphical representations (comparing actual to simulated data) and fit indices indicate that health anxiety is more accurately represented as a dimensional rather than a categorical construct.

CONCLUSIONS

Health anxiety is better represented as a dimensional construct. Implications for theory development and clinical practice are examined.

Assessing laparoscopic skills in the novice

Graduate-entry degrees are common in the US and Australia and are offered by 14 universities in the UK. The University of Nottingham has recently seen the integration of its graduate-entry medicine (GEM) students with its traditional medical undergraduates (BMedSci) on their first clinical attachment. Those pursuing a surgical career will be subject to shortened training as part of Modernising Medical Careers. Furthermore, the increase in minimally invasive techniques will lead to simulator training being utilised as this is a method to which laparoscopic skills acquisition lends itself. A number of validated curricula have been developed since the use of simulators was first suggested as a tool for endoscopic surgical training. Indeed, recent work has shown that simulation may improve psychomotor skills within the context of a surgical procedure.

Acceptability of blood and blood substitutes

Alternatives to donor blood have been developed in part to meet increasing demand. However, new biotechnologies are often associated with increased perceptions of risk and low acceptance. This paper reviews developments of alternatives and presents data, from a field-based experiment in the UK and Holland, on the risks and acceptance of donor blood and alternatives (chemical, genetically modified and bovine). UK groups perceived all substitutes as riskier than the Dutch. There is a negative association between perceived risk and acceptability. Solutions to increasing acceptance are discussed in terms of implicit attitudes, product naming and emotional responses.

Factors associated with outcome after interventional treatment of symptomatic iliac vein compression syndrome

BACKGROUND

Iliac vein compression syndrome (IVCS) results from compression of the left iliac vein by the overlying right iliac artery against the pelvic brim. In many cases, patients are symptomatic. In symptomatic cases, management consists of angioplasty and stenting. Although therapy is often initially successful, factors associated with long-term outcome have been poorly defined. The purpose of this study was to identify factors associated with stent patency.

METHODS

The medical records of all patients who underwent iliac vein percutaneous transluminal angioplasty and stenting from January 1996 to December 2006 for symptomatic IVCS were reviewed retrospectively. There were 50 women and 8 men, with a mean age of 42 years (median, 39 years; range, 17-71 years). Primary, assisted primary, and secondary patency rates were determined. Patient characteristics and clinical variables were evaluated by univariate and multivariate analysis to determine association with vein patency.

RESULTS

Symptoms consisted of lower extremity swelling (81%) and lower extremity pain (67%). Iliac vein obstruction was treated with pharmacologic thrombolysis (31% of patients) and mechanical thrombus fragmentation (17% of patients). The primary, assisted primary, and secondary patency rates of angioplasty/stenting were 74.1%, 79.7%, and 85.8% at 1 year and 38.1%, 62.8%, and 73.8% at 5 years, respectively. Using a Cox proportional risk model, male sex (hazard ratio, 6.5; P = .001), recent trauma (hazard ratio, 5.3; P = .001), and age younger than 40 years (hazard ratio, 3.8; P = .015) were associated with decreased primary patency. In the absence of any risk factors, primary patency was 94.4% at 1 year and 63.0% at 5 years, decreasing to 28.6% and 0% for two or more risk factors.

CONCLUSIONS

Patency rates for iliac vein percutaneous transluminal angioplasty and stenting in patients with IVCS can potentially be predicted on the basis of a multivariate model. Assessing risk factors allows for patient stratification and appropriate clinical decision making. Prospective validation of these variables is necessary.

From comparative risk assessment to multi-criteria decision analysis and adaptive management: recent developments and applications

Environmental risk assessment and decision-making strategies over the last several decades have become increasingly more sophisticated, information-intensive, and complex, including such approaches as expert judgment, cost-benefit analysis, and toxicological risk assessment. One tool that has been used to support environmental decision-making is comparative risk assessment (CRA), but CRA lacks a structured method for arriving at an optimal project alternative. Multi-criteria decision analysis (MCDA) provides better-supported techniques for the comparison of project alternatives based on decision matrices, and it also provides structured methods for the incorporation of project stakeholders' opinions in the ranking of alternatives. We argue that the inherent uncertainty in our ability to predict ecosystem evolution and response to different management policies requires shifting from optimization-based management to an adaptive management paradigm. This paper brings together a multidisciplinary review of existing decision-making approaches at regulatory agencies in the United States and Europe and synthesizes state-of-the-art research in CRA, MCDA, and adaptive management methods applicable to environmental remediation and restoration projects. We propose a basic decision analytic framework that couples MCDA with adaptive management and its public participation and stakeholder value elicitation methods, and we demonstrate application of the framework to a realistic case study based on contaminated sediment management issues in the New York/New Jersey Harbor.

Percutaneous removal of two self-expanding stent grafts following failed deployment

Insertion of self-expanding stent grafts was attempted in two patients with venous obstruction following unsuccessful venoplasty. One patient with end-stage renal disease had stenosis at the caudal end of the previously placed stent in the right external iliac vein. The second patient was treated for occlusion of multiple stents in the left iliac vein. Two of the stent grafts failed deployment and were subsequently removed percutaneously. New stent grafts were inserted in the intended positions. Despite additional venous access sites with large caliber sheaths, required for retrieval of the failed stent grafts, there were no major complications.

Identification of nutritionally adequate mixtures of vegetable oils by linear programming

OBJECTIVE

To determine the types and proportions of vegetable oils to recommend for a healthy diet.

METHODS

Optimal vegetable oil combinations were designed, using linear programming and, as decision variables, nine single oils and 29 basic food items. 'Oil models' were run to determine whether reasonable amounts of individuals oils or oil mixtures satisfied a set of constraints on essential fatty acids and vitamin E. 'Meal models' were run to test whether selected mixtures could be used as the sole source of added fat in a meal that met micronutrient and macronutrient recommendations.

RESULTS

The cheapest mixture (0.97 euro L(-1)) that solved the oil models contained 81% rapeseed and 19% sunflower oils. About 10-15 g of this mixture, alone or with olive, soya bean, wheat germ or walnut oils, also solved the meal models. Mixtures that contained a high proportion (>or=50%) of the tasty olive and walnut oils also solved the models but were more expensive (4.9 euro L(-1) and 8.5 euro L(-1), respectively).

CONCLUSIONS

The consumption of a mixture composed of rapeseed and sunflower oils in a 4 : 1 proportion is an inexpensive and simple way to meet current dietary recommendations for essential fatty acids and vitamin E, favouring overall dietary nutrient adequacy.

Pilot study in the development of an interactive multimedia learning environment for sexual health interventions: a focus group approach

In the UK there are high rates of sexually transmitted infections and unintended pregnancies amongst young people. There is limited and contradictory evidence that current sexual health education interventions are effective or that they improve access to appropriate sexual health services. This paper describes the outcome of focus group work with young people that was undertaken to inform the design of an Interactive Multimedia Learning Environment that incorporates message framing, intended for use in sexual health promotion. The focus group work addressed sexual attitudes, behaviour, risk perception, and knowledge of sexual health and sexual health services in Nottingham. The results provided new insights into young peoples' sexual behaviour, and their diversity of knowledge and beliefs. Common themes expressed regarding sexual health services included concerns about confidentiality, lack of confidence to access services and fear of the unknown. The results showed that while the adolescents are reasonably knowledgeable about infection, they do not know as much about the relevant services to treat it. This work emphasizes the need for user involvement throughout the design and development of a sexual health intervention, and will form the basis of the next part of the project.

Unhappiness and dissatisfaction in doctors cannot be predicted by selectors from medical school application forms: a prospective, longitudinal study

BACKGROUND

Personal statements and referees' reports are widely used on medical school application forms, particularly in the UK, to assess the suitability of candidates for a career in medicine. However there are few studies which assess the validity of such information for predicting unhappiness or dissatisfaction with a career in medicine. Here we combine data from a long-term prospective study of medical student selection and training, with an experimental approach in which a large number of assessors used a paired comparison technique to predict outcome.

METHODS

Data from a large-scale prospective study of students applying to UK medical schools in 1990 were used to identify 40 pairs of doctors, matched by sex, for whom personal statements and referees' reports were available, and who in a 2002/3 follow-up study, one pair member was very satisfied and the other very dissatisfied with medicine as a career. In 2005, 96 assessors, who were experienced medical school selectors, doctors, medical students or psychology students, used information from the doctors' original applications to judge which member of each pair of doctors was the happier, more satisfied doctor.

RESULTS

None of the groups of assessors were significantly different from chance expectations in using applicants' personal statements and the referees' reports to predict actual future satisfaction or dissatisfaction, the distribution being similar to binomial expectations. However judgements of pairs of application forms from pairs of doctors showed a non-binomial distribution, indicating consensus among assessors as to which doctor would be the happy doctor (although the consensus was wrong in half the cases). Assessors taking longer to do the task concurred more. Consensus judgements seem mainly to be based on referees' predictions of academic achievement (even though academic achievement is not actually a valid predictor of happiness or satisfaction).

CONCLUSION

Although widely used in medical student selection to assess motivation, interest and commitment to a medical career, the personal statement and the referee's report cannot validly be used by assessors, including experienced medical school selectors, to identify doctors who will subsequently be dissatisfied with a medical career.

Fatty acid metabolism in human preimplantation embryos

BACKGROUND

Little is known of fatty acid metabolism in human embryos. This information would be useful in developing metabolic tests of embryo quality and improving embryo culture media.

METHODS

The fatty acid composition of human embryos and their ability to accumulate 13C labelled fatty acids was assessed in relation to the stage of development using gas-chromatography and combustion-isotope-ratio-mass spectrometry.

RESULTS

Compared with embryos which did not develop beyond the 4-cell stage, those that did had significantly higher concentrations of the unsaturates, linoleic (12% versus 3%; P=0.02) and oleic (14% versus 7%; P=0.02), and a lower concentration of total saturates (62% versus 77%; P=0.04). There was uptake of both 13C linoleic and palmitic, but the developmental pattern was different for each fatty acid. The net accumulation in pmol/embryo/24h for palmitic was 1 at the 2-cell to <8-cell stage, 4 at the 8-cell-morula stage and negligible at the blastocyst stage. For linoleic, there was little net accumulation at the 2-cell to <8-cell stage, 8 (8-cell-morula stage) and 17 pmol/embryo/24 h (blastocyst stage).

CONCLUSION

Preimplantation human embryos actively take up individual fatty acids at different rates at different stages of development. The high unsaturated concentration at the later stages of development may be explained by preferential uptake of linoleic acid.

Perceived safety of donor blood and blood substitutes for transfusion: the role of informational frame, patient groups and stress appraisals

Patients express concerns about the safety of donated blood. Do they have similar concerns about potential 'blood substitutes' and does the way information is presented on these options alter patients' perceptions? A two (informational frame: gain or loss) by four (transfusion type: human donor blood, human haemoglobin, bovine haemoglobin or perfluorocarbon emulsion substitutes) by three (patient group: adult haemophiliac/leukaemia patients, relatives/friends of haemophiliac/leukaemia patients and controls) between-subjects design was used. There were 82 patients, 118 relatives/friends and 263 controls from the UK. Blood substitutes were perceived as being significantly less safe than donor blood. Perceptions of safety were greater when transfusion information (regardless of transfusion type or patient group) was presented as gains rather than losses. Different demographic and psychological factors predicted perceived safety (e.g. sex) and perceived risk (e.g. age and experience).

Redefining the role of arterial imaging in the management of penetrating zone 3 neck injuries

The purpose of this study was to assess the role of arteriography (AG) in the diagnosis and treatment of vascular trauma in patients with zone 3 penetrating neck injuries. The records of all cases of penetrating neck trauma for the past 14 years at a level 1 trauma center were reviewed retrospectively. Eight hundred forty-four penetrating neck injuries were documented, of which 72 (8.5%) traversed zone 3 of the neck (gunshot, 35; stab, 32; shotgun, 5). Twenty patients (27%) had hard signs of vascular injury (hemorrhage, expanding hematoma, bruit, thrill, neurologic deficit). Twelve of these (60%) underwent immediate exploration, 1 had no significant injury, and 11 had successful surgical repair or ligation of the vascular injury. AG in the other eight patients with hard signs revealed injuries requiring embolization (three patients), urokinase infusion (one patient), and observation (three patients) and one normal examination. Fifty-two patients had no hard signs of vascular injury. Twenty-four of these underwent AG, of which 18 were negative. Positive findings included internal carotid artery narrowings (two patients), external compression of the internal carotid artery (one patient), vertebral artery intimal flap (one patient), and nonbleeding injuries to small, noncritical arteries (two patients), none of which required treatment. Twenty-four of the remaining 28 patients were observed clinically, and 4 patients had negative explorations. Nine patients had ultrasonography performed, but these examinations did not yield any useful information. The absence of hard signs reliably excludes surgically significant vascular injuries in penetrating zone 3 neck trauma, suggesting that AG is not necessary. Hard signs in stable patients should mandate AG because these vascular injuries may be amenable to endovascular therapy.

Agreement of aspiration tests using barium videofluoroscopy, salivagram, and milk scan in children with cerebral palsy

To study the agreement between three tests for aspiration, barium videofluoroscopy, salivagram, and milk scan we studied 63 children with severe non-ambulant spastic quadriplegic cerebral palsy (CP) aged 14 months to 16 years (32 males, 31 females). The salivagram was most frequently positive (56%, 95% confidence interval 43 to 68%); the next most frequently positive was barium videofluoroscopy when aspiration was defined as the presence of either laryngeal penetration of material or frank aspiration (39%, 95% confidence interval 26 to 53%). The milk scan was rarely positive (6%, 95% confidence interval 2 to 16%). Agreement between the tests of aspiration was poor. The maximum agreement (kappa=0.20) was between aspiration as diagnosed with the salivagram and by barium videofluoroscopy. Positive tests for aspiration are frequent in children with severe CP. Frequency varies widely depending on the investigation used. There is poor agreement between tests used for the diagnosis of aspiration. This information is of importance in assessing the significance of test results.

Trustworthiness of information about blood donation and transfusion in relation to knowledge and perceptions of risk: an analysis of UK stakeholder groups

There is evidence that the public perceive blood transfusion as risky, and there is a growing literature exploring factors associated with perceived transfusion risk. One contributory factor might be the types of information different key stakeholders (e.g. general practitioners, anaesthetists, health/life style journalists and blood donors) rely on for information. This article addresses four unanswered questions about transfusion/donation risk, namely (1) do different stakeholder groups perceive different sources of information as more or less trustworthy, (2) to what extent is the perceived trustworthiness related to levels of knowledge and perceived risk, (3) is optimistic bias observed across the stakeholder groups, and (4) is knowledge related to levels of perceived risk across the stakeholder groups? A questionnaire survey was used to assess the trustworthiness of sources of information, perceived risk and knowledge. Four stakeholder groups were examined, namely (1) blood donors (n = 250), (2) general practitioners (n = 88), (3) anaesthetists (n = 143) and (4) medical journalists (n = 20). The results showed that (1) judgements of trustworthiness vary as a function of stakeholder groups, and (2) it is what people think they know rather than what they actually know that is related to judgements of trustworthiness and perceptions of risk. Judgements of trustworthiness are generally unrelated to perceptions of risk, and all stakeholder groups show optimistic bias. The implications of these findings for risk communication, specifically relating to transfusion medicine, are discussed.

Benefit and risk perceptions in transfusion medicine: blood and blood substitutes

Blood transfusion is a remarkably safe, routine procedure in clinical medicine. However, little attention has focused on the perceptions of risk associated with the receipt of blood, blood products or 'blood substitutes'. It is pertinent to ask (i) what key stakeholder groups know about transfusion, (ii) how safe they perceive blood/blood products to be, (iii) how the latter information might influence their own and others' perceptions of risk linked to transfusion, and (iv) the extent to which approved blood substitutes might be preferred over autologous or donor blood. An appreciation of what stakeholders perceive to be the benefits and risks of the receipt of blood and blood substitutes will inform future transfusion strategies. To obtain such information, a programme of research has been initiated at Nottingham. Surveys have targeted key stakeholder groups, namely, UK adult blood donors and nondonors, anaesthetists, general practitioners and health care journalists. Experimental studies examining message framing and cueing have also been conducted with undergraduate students. Such research will improve misunderstandings about current issues associated with blood donation and transfusion against the backdrop of changing public trust of health care professionals and attitudes and expectations on blood safety and benefits of blood substitutes.

Complementary food supplements to achieve micronutrient adequacy for infants and young children

Many children in developing countries survive on a nutritionally inadequate diet. Dietary inadequacies during the complementary feeding period can be prevented by using complementary food supplements (CFSs) such as water dispersible or crushable micronutrient tablets, micronutrient sprinkles added to food just before feeding, or fortified spreads added to food just before feeding or fed as a snacks. A meeting was convened to discuss technical and operational issues related to the development of these new approaches and to identify knowledge gaps. The technical issues covered: what micronutrients to include, tolerable upper intake limits, bioavailability, micronutrient and macronutrient stability, package systems and amounts, encapsulation technologies, methods to limit or eliminate allergens, bacterial and chemical contamination, interactions between CFSs and complementary foods, and flavoring agents. Operational issues included: identifying the market positioning of CFSs, cost positioning of CFSs, regulatory requirements, CFS production and technology transfer, quality assurance, and public-private sector partnership and coordination. Intervention trials are needed to determine the efficacy of CFSs in preventing micronutrient deficiencies. Other important knowledge gaps relate to technical and operational issues. Sprinkles and tablets are produced using well-known technologies, but further research is needed to modify them for use as CFSs. Spread development is not as advanced as sprinkle and tablet development, and further research is needed to improve the technology. Although none of the products is ready for widespread use, enough information is available to set research priorities and accelerate product development and implementation.

Thoracoscopic resection of Castleman disease: case report and review

Castleman disease is an uncommon entity, most often occurring in patients presenting with localized mediastinal lymph node enlargement. While surgical resection is the preferred treatment, there are concerns about approaching this highly vascular tumor with thoracoscopy. We present the second reported case of thoracoscopic resection of a patient with Castleman disease and review the literature.

Transvaginal ultrasound-guided oocyte aspiration for production of embryos <i>in vitro</i>

Abstract. reproductive potential in genetically valuable animals (BEAL et al., 1992). Now that repeatable oocyte retrieval methods are being fine-tuned, it is likely these procedures will become routinely used to obtain oocytes for further gamete and embryo research and also by seedstock producers for in vitro embryo production from farm animals in the commercial sector. The use of transvaginal ultrasound-guided oocyte aspiration and IVF procedure does offer an alternative to cattle producers who have genetically valuable cows that for some reason are unable to produce viable embryos through standard embryo collection procedures. This technology can be used on oocytes harvested from older ovulating or nonovulating cows, females with physical injuries (e.g., fractured leg) and problem cows having an abnormal cervix. Good success has been reported using IVF procedures on oocytes obtained from supplemental follicles of cows with cystic ovarian disease. With IVF the potential exists for more embryos to be produced in a shorter period of time, since the procedure can be repeated on the same cow 3 to 4 times or more a month. At this station, we are harvesting oocytes from early postpartum (< 40 days) beef and dairy cattle, before the female begins cyclic activity. The approach allows the opportunity to produce one or more extra calves from the cow before she is mated for a natural pregnancy. Currently, transvaginal ultrasound-guided oocyte aspiration is now being used to harvest valuable oocytes from minor farm animal breeds, from domestic females representing rare bloodlines, clinically infertile females and reproductively senescent cows. Research continues to find applications for this technology, including harvesting oocytes from young prepubertal heifers and early postpartum beef cows for in vitro embryo production. The use of ultrasound-guided oocyte aspiration should not be overlooked to obtain oocytes for in vitro embryo production and to aid in germplasm preservation of endangered exotic species.

Theoretical accounts of Gulf War Syndrome: from environmental toxins to psychoneuroimmunology and neurodegeneration

Non-specific illness includes a wide variety of symptoms: behavioural (e.g., reduced food and water intake), cognitive (e.g., memory and concentration problems) and physiological (e.g., fever). This paper reviews evidence suggesting that such symptoms can be explained more parsimoniously as a single symptom cluster than as a set of separate illnesses such as Gulf War Syndrome (GWS) and chronic fatigue syndrome (CFS). This superordinate syndrome could have its biological basis in the activity of pro-inflammatory cytokines (in particular interleukin-1: IL-1), that give rise to what has become known as the 'sickness response'. It is further argued that the persistence of non-specific illness in chronic conditions like GWS may be (in part) attributable to a bio-associative mechanism (Ferguson and Cassaday, 1999). In the case of GWS, physiological challenges could have produced a non-specific sickness response that became associated with smells (e.g., petrol), coincidentally experienced in the Persian Gulf. On returning to the home environment, these same smells would act as associative triggers for the maintenance of (conditioned) sickness responses. Such associative mechanisms could be mediated through the hypothalamus and limbic system via vagal nerve innervation and would provide an explanation for the persistence of a set of symptoms (e.g., fever) that should normally be short lived and self-limiting. We also present evidence that the pattern of symptoms produced by the pro-inflammatory cytokines reflects a shift in immune system functioning towards a (T-helper-1) Th1 profile. This position contrasts with other immunological accounts of GWS that suggest that the immune system demonstrates a shift to a Th2 (allergy) profile. Evidence pertaining to these two contrasting positions is reviewed.

Confidence in the safety of blood for transfusion: the effect of message framing

BACKGROUND

Blood transfusion is a universally used, life-saving medical intervention. However, there are increasing concerns among patients about blood safety. This study investigates the effect of message framing, a means of presenting information, on confidence in blood transfusion safety.

STUDY DESIGN AND METHODS

The same factual information regarding the safety of blood for transfusion was presented to a sample of 254 adult students (donors and nondonors) as either a gain frame (lives saved), a loss frame (lives lost), or a combined frame (a loss frame expressed in a positive context). This provided a basic two-way, between-subjects design with 1) blood donation history (donors vs. nondonors) and 2) message frame (gain, loss, and combined) functioning as the between-groups factors. It was hypothesized that participants would consider blood safer if information was presented as a gain frame. The role of stress appraisals as potential mediators of the framing effect was also explored.

RESULTS

As predicted, participants receiving the gain-frame information were significantly more confident of the safety of blood for transfusion than those receiving loss-frame information or both. This was unaffected by donation history or appraisals of stress associated with transfusion. The extent to which blood was considered safe was negatively associated, independently of framing effects, with perceptions that transfusion was threatening.

CONCLUSION

Information about transfusion should be conveyed to patients in a form focusing on the positive, rather than the negative, known facts about the safety of blood.

Intellect and somatic health: associations with hypochondriacal concerns, perceived threat and fainting

BACKGROUND

: Compared to the other domains of the Big 5, intellect has been relatively underresearched with regard to somatic health outcomes. It is argued that this, in part, is because specific hypotheses concerning intellect and somatic health have not been formulated. It is argued that intellect is related to both alexithymia and hypnotic ability. As such the High Risk Model of Threat Perception forms one useful theoretical framework for generating hypotheses about intellect and somatic health. On this basis it is hypothesised that intellect should show a U-shaped relationship to hypochondriacal concerns, a positive association with appraisals of threat and loss, and a negative association with levels of self-reported vasovagal syncope (feelings of faintness).

METHODS

Two cross-sectional studies, using student samples (n = 205, 179), examined the relationships between intellect and hypochondriacal concerns as well as intellect and appraisals of threat and loss. A third prospective study, using a sample of blood donors (n = 373), examined the relationship between levels of self-reported vasovagal syncope and intellect.

RESULTS

Compared to the other domains of the Big 5, intellect demonstrated a U-shaped association with hypochondriacal concerns, a positive association with perceived threat and loss and a negative association with fainting. The negative association with fainting remained once incidence of previous fainting, the number of previous blood donations and emotional stability were held as covariates.

CONCLUSIONS

Intellect is associated in a number of important ways with a variety of psychosomatic variables.

RNA expression in the early characterization of hepatotoxicants in Wistar rats by high-density DNA microarrays

High-density microarrays are useful tools to study gene expression for the purpose of characterizing functional tissue changes in response to the action of drugs and chemicals. To test whether high-density expression data can identify mechanisms of toxicity and to identify an unknown sample through its RNA expression pattern, groups of male Wistar rats were administered 6 hepatotoxicants. The compounds chosen for this study were microcystin-LR (MLR), phenobarbital (PB), lipopolysaccharide (LPS), carbon tetrachloride (CT), thioacetamide (THA), and cyproterone acetate (CPA). These hepatotoxicants are known to induce adverse liver effects through different mechanisms. Liver mRNA was isolated and used to generate biotinylated cRNA for hybridization to a custom 1,600-rat gene DNA microarray. Treatment correlation matrices analyzed hybridization data from a hepatotoxicant-blinded sample, with gene expression coefficients (GEC) evaluated by means of hierarchical cluster analysis and visual representation as dendrograms. The experimental liver toxicity from the different treatments was confirmed by means of concurrent histopathology, liver enzymes, and bilirubin assays. This toxico genomic analysis identified multiple genes and groups of genes that were affected by the hepatotoxicants on study, indicating that high-density microarray expression data are useful to identify groups of genes involved in toxicity. In addition, the mRNA expression profile of an unidentified sample can be accurately identified when compared with the expression profiles resident in the data set. This study supports the use of gene expression-profiling technology to determine or to predict toxic liver effects.

Sex and sexual orientation: the effect of group membership on individuals' judgments about self and others' HIV risk

No previous study has directly compared homosexual and heterosexual men and women's perceptions of HIV risk. In fact, empirical research focusing on homosexual women's perception of HIV risk is scarce. This paper, therefore, examines whether homosexual and heterosexual women and men (N = 60) make varied self and other (peer and non-peer) HIV risk judgments. The paper also examines the roles of motivational (health anxiety) and cognitive (HIV knowledge) factors in relation to HIV risk judgments. The results show that each group held different perceptions of risk for various "other" groups. Only homosexual men showed evidence for an optimistic bias, whereas homosexual women showed evidence of realistic perceptions. Both cognitive and motivational factors were shown to be associated with risk judgments for homosexual women and heterosexual men. Methodologically the use of Multidimensional scaling as an analytic strategy is recommended.

Hypochondriacal concerns, somatosensory amplification, and primary and secondary cognitive appraisals

This paper uses data from four studies (N = 150, 150, 154 and 79) to examine the associations between hypochondriacal concerns (HCs) and stress appraisals (primary and secondary). A search activity account of HCs suggests that increased levels of HCs should be associated with positive appraisals of a stressful situation (i.e., increased levels of perceived challenge and perceived control). However, the results indicated that in terms of primary appraisals, increased perceptions of threat and not challenge were consistently associated with increased levels of HCs. Further, the results indicated that the association between threat and HCs is mediated by somatosensory amplification. Consistent with the search activity account it is shown that increased levels of perceived control (secondary appraisals) are associated with increased levels of HCs. The association for perceived control remains once variance due to somatosensory amplification is partialled and generalizes to a sample of patients with a sexually transmitted infection. The results are interpreted in relation to the transactional model of the stress process.

Hypochondriacal concerns and the five factor model of personality

Using data from two studies (Ns = 205 and 161), this article examines the associations between the domains of the five factor model of personality and hypochondriacal concerns (HCs). These associations are explored once covariation due to other related traits (somatosensory amplification) and comorbidity factors (anxiety, depression, and somatic symptom reporting) have been controlled. As predicted, emotional stability was associated with most criteria related to HCs and agreeableness was negatively associated with the perceived inadequacy of a physician's explanation. Conscientiousness was negatively associated with HCs. These associations remained after partialing the comorbidity factors and somatosensory amplification. The discussion focuses on the particular role of agreeableness and conscientiousness in relation to HCs.

Associations between primary appraisals and life-events while controlling for depression

OBJECTIVES

The main objective of this paper was to explore the associations between life-events and primary appraisals (threat, challenge and loss) controlling for depression. It was predicted that specific associations between life-events and primary appraisals would remain once depression had been partialled. A subgoal of this paper was to develop a content analytic coding frame for student life-events.

DESIGN

This study was a retrospective survey in which participants provided accounts of recent stressful encounters, and completed indices of primary appraisals and depression.

METHOD

The participants were 979 undergraduates who provided descriptions of life-events. A subsample of 391 provided additional information on primary appraisals and depression. The primary outcomes were the partial correlations between life-events and primary appraisals.

RESULTS

There were significant associations between life-events and primary appraisals above and beyond variance explained by depression. Results also indicated that the definition of loss appraisals could be extended to include events that were related to anticipated future loss, especially if the event was also perceived as threatening. Also certain self-defined negative life-events were appraised as positive. Life-events were shown to vary systematically as a function of external constraints (e.g. stage of the academic year).

CONCLUSIONS

A variety of events were associated with loss appraisals and this may have implications for risk factors in depression.

A competency model for general practice: implications for selection, training, and development

BACKGROUND

The role of the general practitioner (GP) has changed significantly over the past decade. This problem is compounded by growing concern over postgraduate attrition rates from medicine, with current estimates as high as 19%.

AIM

To define a comprehensive model of the competencies required for the job role of GP.

METHOD

Three independent studies were conducted to define GP competencies including (1) critical incidents focus groups with GPs, (2) behavioural coding of GP-patient consultations, and (3) critical incidents interviews with patients. Study 1 was conducted with GPs (n = 35) from the Trent region. Study 2 involved observation of GP-patient consultations (n = 33 consultations), and Study 3 was conducted with patients (n = 21), all from a Midlands-based medical practice.

RESULTS

The data collected from the three studies provided strong evidence for a competency model comprising 11 categories with a summary of the associated behavioural descriptions. Example competencies included empathy and sensitivity, communication skills, clinical knowledge and expertise, conceptual thinking, and coping with pressure.

CONCLUSIONS

Triangulation of results was achieved from three independent studies. The competencies derived imply that a greater account of personal attributes needs to be considered in recruitment and training, rather than focusing on academic and clinical competency alone. The model could be employed for future research in design of selection techniques for the role of GP.

Pupils' causal attributions for difficult classroom behaviour

BACKGROUND

Studies of causal attributions within educational contexts have tended to concentrate on academic performance. There have been a smaller number of investigations of teachers' attributions for pupils' behaviour in school.

AIMS

The present study examines the causal attribution made by pupils for difficult behaviour in classrooms. It reveals the structure of these attributions and serves as a comparison with the teacher studies.

SAMPLE

The participants were 105 pupils (52 males and 53 females) in the first year of secondary schooling, all drawn from the same inner city school.

METHOD

Four initial small group interviews were used to identify a wide range of factors that pupils viewed as being causes of difficult classroom behaviour in the 18 primary schools they had previously attended. A questionnaire was then constructed incorporating items from these discussions and administered to the whole of the year group of pupils, but omitting the participants in the initial group discussions.

RESULTS

The results of a factor analysis indicated that pupils' attributions for misbehaviour at school were best represented by four factors: (1) 'fairness of teacher's actions', (2) 'pupil vulnerability', (3) 'adverse family circumstances' and (4) 'strictness of classroom regime'. While there were no gender differences, pupils saw the 'fairness of teacher's actions' and 'pupil vulnerability' as more significant contributors to pupil misbehaviour than either 'adverse family circumstances' or 'strictness of classroom regime'.

CONCLUSION

The attributions by pupils for difficult classroom behaviour differ markedly from those obtained in studies of teachers. Policy and practice initiatives which do not attend to conflicting attributional styles are unlikely to succeed in improving levels of pupil behaviour in schools.

The surgical management of bacterial valvular endocarditis

Bacterial endocarditis is an important cause of cardiac valvular problems. The diagnosis of bacterial endocarditis can be difficult, and, often, an aggressive clinical evaluation including serial blood cultures is necessary. The pathophysiology of endocarditis is changing with the rise of intravenous drug use; staphylococci are an increasingly common cause. Endocarditis often warrants surgical intervention. Operations for bacterial endocarditis range from valve repair to valve replacement to homograft replacement. The operations are technically challenging, but new methods of myocardial protection have markedly improved the surgical outcomes. Valve excision is an option for intravenous drug users with tricuspid valve endocarditis. Surgical management of endocarditis is a technically challenging but rewarding procedure that should be offered to appropriate patients.

The Gulf War and illness by association

The symptoms of Gulf War Syndrome (GWS) closely correspond to the physiological and behavioural sequelae of an interleukin-1 (IL-1) mediated sickness response. We propose that this response can account for the variability in its symptomatology. Furthermore, the persistence of GWS can be accounted for by an associative process, whereby the smells/tastes of war become linked with the physiological reaction to environmental stressors encountered in the Gulf and/or the 'cocktail' of drugs given to the soldiers. As required, the IL-1 response is conditionable.

Role of electrophilic and general base catalysis in the mechanism of Escherichia coli uracil DNA glycosylase

Escherichia coli uracil DNA glycosylase (UDG) catalyzes the hydrolysis of premutagenic uracil bases in DNA by flipping the deoxyuridine from the DNA helix [Stivers, J. T., et al. (1999) Biochemistry 38, 952]. A general acid-base mechanism has been proposed whereby His187 facilitates leaving group departure by protonating the O2 of uracil and Asp64 activates a water molecule for nucleophilic attack at C1' of the deoxyribose. Detailed kinetic studies on the H187Q, H187A, and D64N mutant enzymes indicate that Asp64 and His187 stabilize the chemical transition state by 5.3 and 4.8 kcal/mol, respectively, with little effect on substrate or product binding. The pH dependence of k(cat) for wild-type and H187Q UDG indicates that an unprotonated group in the enzyme-substrate complex (pK(a) = 6.2 +/- 0.2) is required for catalysis. This unprotonated group has a small DeltaH of ionization (-0.4 +/- 1.7 kcal/mol) and is absent in the pH profile for D64N UDG, suggesting that it corresponds to the general base Asp64. The pH dependence of k(cat) for wild-type, H187Q, and D64N UDG shows no evidence for an essential protonated group over the pH range of 5.5-10. Hence, the pK(a) of His187 must be outside this pH range if it serves as an electrophilic catalyst. These results support a mechanism in which Asp64 serves as the general base and His187 acts as a neutral electrophile, stabilizing a developing negative charge on uracil O2 in the transition state. In the following paper of this issue we establish by crystallography and heteronuclear NMR spectroscopy that the imidazole of His187 is neutral during the catalytic cycle of UDG.

Characterization of the adduct formed from the reaction between homocysteine thiolactone and low-density lipoprotein: antioxidant implications

Homocysteine thiolactone is a cyclic thioester that is implicated in the development of atherosclerosis. This molecule will readily acylate primary amines, forming a homocystamide adduct, which contains a primary amine and a thiol. Here, we have characterized and evaluated the antioxidant potential of the homocystamide-low-density lipoprotein (LDL) adduct, a product of the reaction between homocysteine thiolactone and LDL. Treatment of LDL with homocysteine thiolactone resulted in a time-dependent increase in LDL-bound thiols that reached approximately 250 nmol thiol/mg LDL protein. The thiol groups of the homocystamide-LDL adduct were labeled with the thiol-reactive nitroxide, methanethiosulfonate spin label. Using paramagnetic relaxing agents and the electron spin resonance spin labeling technique, we determined that the homocystamide adducts were predominately exposed to the aqueous phase. The homocystamide-LDL adduct was resistant to myoglobin- and Cu2(+)-mediated oxidation (with respect to native LDL), as measured by the formation of conjugated dienes and thiobarbituric acid reactive substances, and the depletion of vitamin E. This antioxidant effect was due to increased thiol content, as the effect was abolished with N-ethylmaleamide pre-treatment. We conclude that the reaction between homocysteine thiolactone and LDL generates an LDL molecule that is more resistant to oxidative modification than native LDL. The potential relationship between the homocystamide-LDL adduct and the development of atherosclerosis is discussed.

Hypochondriacal concerns, symptom reporting and secondary gain mechanisms

Hypochondriacal concerns (HCs) and somatic symptom reporting (SSR) are associated. However, HCs are believed to be linked to the ego-defence coping strategy of avoiding help and SSR is believed to be linked to secondary gain. One hundred and twenty undergraduate students completed measures of HCs, SSR and the Desire for Control (DC) Scale. Subscales of the DC scale were used as indices of help avoidance and secondary gain. Both hierarchical multiple linear regression and LISREL structural modelling were used to control for the confound between HCs and SSR and explore the links with help avoidance and secondary gain. HCs were found to be primarily associated with an increased desire to strive for independence (avoid help) and levels of SSR were associated with the desire to have others make decisions (secondary gain).