Chronic Elevation of Endothelin-1 Alone May Not Be Sufficient to Impair Endothelium-Dependent Relaxation

Endothelin-1 (ET-1) is a powerful vasoconstrictor peptide considered to be causally implicated in hypertension and the development of cardiovascular disease. Increased ET-1 is commonly associated with reduced NO bioavailability and impaired vascular function; however, whether chronic elevation of ET-1 directly impairs endothelium-dependent relaxation (EDR) remains elusive. Herein, we report that (1) prolonged ET-1 exposure (ie, 48 hours) of naive mouse aortas or cultured endothelial cells did not impair EDR or reduce eNOS (endothelial NO synthase) activity, respectively (P>0.05); (2) mice with endothelial cell-specific ET-1 overexpression did not exhibit impaired EDR or reduced eNOS activity (P>0.05); (3) chronic (8 weeks) pharmacological blockade of ET-1 receptors in obese/hyperlipidemic mice did not improve aortic EDR or increase eNOS activity (P>0.05); and (4) vascular and plasma ET-1 did not inversely correlate with EDR in resistance arteries isolated from human subjects with a wide range of ET-1 levels (r=0.0037 and r=-0.1258, respectively). Furthermore, we report that prolonged ET-1 exposure downregulated vascular UCP-1 (uncoupling protein-1; P<0.05), which may contribute to the preservation of EDR in conditions characterized by hyperendothelinemia. Collectively, our findings demonstrate that chronic elevation of ET-1 alone may not be sufficient to impair EDR.

Overproduction of endothelin-1 impairs glucose tolerance but does not promote visceral adipose tissue inflammation or limit metabolic adaptations to exercise

Endothelin-1 (ET-1) is a potent vasoconstrictor and proinflammatory peptide that is upregulated in obesity. Herein, we tested the hypothesis that ET-1 signaling promotes visceral adipose tissue (AT) inflammation and disrupts glucose homeostasis. We also tested if reduced ET-1 is a required mechanism by which exercise ameliorates AT inflammation and improves glycemic control in obesity. We found that 1) diet-induced obesity, AT inflammation, and glycemic dysregulation were not accompanied by significantly increased levels of ET-1 in AT or circulation in wild-type mice and that endothelial overexpression of ET-1 and consequently increased ET-1 levels did not cause AT inflammation yet impaired glucose tolerance; 2) reduced AT inflammation and improved glucose tolerance with voluntary wheel running was not associated with decreased levels of ET-1 in AT or circulation in obese mice nor did endothelial overexpression of ET-1 impede such exercise-induced metabolic adaptations; 3) chronic pharmacological blockade of ET-1 receptors did not suppress AT inflammation in obese mice but improved glucose tolerance; and 4) in a cohort of human subjects with a wide range of body mass indexes, ET-1 levels in AT, or circulation were not correlated with markers of inflammation in AT. In aggregate, we conclude that ET-1 signaling is not implicated in the development of visceral AT inflammation but promotes glucose intolerance, thus representing an important therapeutic target for glycemic dysregulation in conditions characterized by hyperendothelinemia. Furthermore, we show that the salutary effects of exercise on AT and systemic metabolic function are not contingent on the suppression of ET-1 signaling.

Removal of interscapular brown adipose tissue increases aortic stiffness despite normal systemic glucose metabolism in mice

Brown adipose tissue (BAT) is considered protective against obesity and related cardiometabolic dysfunction. Indeed, activation of BAT improves glucose homeostasis and attenuates cardiovascular disease development. However, whether a reduction in BAT mass perturbs metabolic function and increases risk for cardiovascular disease remains largely unknown. To address this question, C57BL/6J male mice underwent a sham procedure or surgical bilateral excision of interscapular BAT (iBATx) and were fed a normal chow or a Western diet for 18 wk, creating four groups ( n = 10/group). Mice were housed at 25°C. As expected, the Western diet increased final body weight and adiposity; however, contrary to our hypothesis, iBATx did not potentiate adiposity independent of diet. Furthermore, iBATx did not affect indexes of glycemic control (HbA_1c, fasting glucose and insulin, and glucose area under the curve during a glucose tolerance test) and produced minimal-to-no effects on lipid homeostasis. The absence of metabolic disturbances with iBATx was not attributed to regrowth of iBAT or a "browning" or proliferative compensatory response of other BAT depots. Notably, iBATx caused an increase in aortic stiffness in normal chow-fed mice only, which was associated with an increase in aortic uncoupling protein-1. Collectively, we demonstrated that, at 25°C (i.e., limited thermal stress conditions), a substantial reduction in BAT mass via iBATx does not disrupt systemic glucose metabolism, challenging the current dogma that preservation of BAT is obligatory for optimal metabolic function. However, iBATx caused aortic stiffening in lean mice, hence supporting the existence of an interplay between iBAT and aortic stiffness, independent of alterations in glucose homeostasis.

Deletion of UCP1 enhances ex vivo aortic vasomotor function in female but not male mice despite similar susceptibility to metabolic dysfunction

Females are typically more insulin sensitive than males, which may be partly attributed to greater brown adipose tissue (BAT) activity and uncoupling protein 1 (UCP1) content. Accordingly, we tested the hypothesis that UCP1 deletion would abolish sex differences in insulin sensitivity and that whitening of thoracic periaortic BAT caused by UCP1 loss would be accompanied with impaired thoracic aortic function. Furthermore, because UCP1 exerts antioxidant effects, we examined whether UCP1 deficiency-induced metabolic dysfunction was mediated by oxidative stress. Compared with males, female mice had lower HOMA- and AT-insulin resistance (IR) despite no significant differences in BAT UCP1 content. UCP1 ablation increased HOMA-IR, AT-IR, and whitening of BAT in both sexes. Expression of UCP1 in thoracic aorta was greater in wild-type females compared with males. Importantly, deletion of UCP1 enhanced aortic vasomotor function in females only. UCP1 ablation did not promote oxidative stress in interscapular BAT. Furthermore, daily administration of the free radical scavenger tempol for 8 wk did not abrogate UCP1 deficiency-induced increases in adiposity, hyperinsulinemia, or liver steatosis. Collectively, we report that 1) in normal chow-fed mice housed at 25°C, aortic UCP1 content was greater in females than males and its deletion improved ex vivo aortic vasomotor function in females only; 2) constitutive UCP1 content in BAT was similar between females and males and loss of UCP1 did not abolish sex differences in insulin sensitivity; and 3) the metabolic disruptions caused by UCP1 ablation did not appear to be contingent upon increased oxidative stress in mice under normal dietary conditions.

Motivation for Participation, Success in Performance and Their Relationship to Individual and Group Satisfaction

The present study examined the interactive effects of participation motivation (task, self, and interaction) expressed in early season and successful performance ( n = 183) experienced throughout the collegiate hockey season upon satisfaction expressed post-season with individual and team performance. The experimental design consisted of a 2 × 2 factorial comprising two levels of motivation (high vs low) and two levels of success (successful vs unsuccessful). The results indicated that success, motivations, and the various interactions had no effect upon satisfaction with individual performance. Both success and high task-motive resulted in heightened levels of satisfaction in regard to team performance.

An Analysis of the Cause-Effect Characteristics of Cohesiveness and Participation Motivation in Intercollegiate Hockey

The purpose of the study was to examine the direction of causality of both cohesion and participation motivation with performance in intercollegiate hockey. The results supported the conclusion that successful performance results in in creased team cohesiveness; team cohesiveness does not produce more successful performance. The findings for participation motivation were equivocal. There was no indication that high self, task and/or affiliation motivation led to more successful performance or that successful performance increased the level of self, task and/or affiliation motivation.

Implications of the Institute of Medicine Report: Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease

The Institute of Medicine (IOM) released a groundbreaking 2010 report, Evaluation of Biomarkers and Surrogate Endpoints in Chronic Disease. Key recommendations included a harmonized scientific process and a general framework for biomarker evaluation with three interrelated steps: (1) Analytical validation -- is the biomarker measurement accurate? (2) Qualification -- is the biomarker associated with the clinical endpoint of concern? (3) Utilization -- what is the specific context of the proposed use?

A randomized controlled trial of mindfulness-based cognitive therapy for bipolar disorder

OBJECTIVE

To compare the efficacy of mindfulness-based cognitive therapy (MBCT) plus treatment as usual (TAU) to TAU alone for patients with bipolar disorder over a 12-month follow-up period.

METHOD

Participants with a DSM-IV diagnosis of bipolar disorder were randomly allocated to either MBCT plus TAU or TAU alone. Primary outcome measures were time to recurrence of a DSM-IV major depressive, hypomanic or manic episode; the Montgomery-Åsberg Depression Rating Scale (MADRS); and Young Mania Rating Scale (YMRS). Secondary outcome measures were number of recurrences, the Depression Anxiety Stress Scales (DASS), and the State Trait Anxiety Inventory (STAI).

RESULTS

Ninety-five participants with bipolar disorder were recruited to the study (MBCT = 48; TAU = 47). Intention-to-treat (ITT) analysis found no significant differences between the groups on either time to first recurrence of a mood episode or total number of recurrences over the 12-month period. Furthermore, there were no significant between-group differences on the MADRS or YMRS scales. A significant between-group difference was found in STAI - state anxiety scores. There was a significant treatment by time interaction for the DAS - achievement subscale.

CONCLUSION

While MBCT did not lead to significant reductions in time to depressive or hypo/manic relapse, total number of episodes, or mood symptom severity at 12-month follow-up, there was some evidence for an effect on anxiety symptoms. This finding suggests a potential role of MBCT in reducing anxiety comorbid with bipolar disorder.

Substance abuse among medical practitioners

This paper reviews the literature relating to the prevalence, causes and treatment of substance abuse and psychiatric illness among doctors. Possible aetiological and pathogenic factors influencing drug-dependent doctors are discussed and some problems which arise in the management of these doctors are raised. Local studies in relation to certain personality factors in medical students, to cause of death in a medical cohort, and preliminary impressions from a study of substance-abusing doctors are reported.

Quantum chemical investigations of charge-transfer interactions in relation to the electronic theory of cancer

The results of ab initio 'supermolecule' calculations of the charge transfer between formamide and methylglyoxal, dimethylglyoxal and ethylglyoxal are compared for several different relative conformations of the constituent molecules. The extent and sign of the charge transfer is similar for all three molecules; the ketoaldehyde acts as an electron acceptor only for the stacked conformation. Similar calculations on alpha-hydroxytetronic acid as a model for ascorbic acid show that it can act as either an acceptor from formamide or a donor to glyoxal.

Timing of decompression and fixation after spinal cord injury--when is surgery optimal?

Spinal cord injury affects a large number of young individuals with a significant cost to affected persons, families and societies both in terms of economic and non-economic costs. To date, our interventions have been limited to prevention, good initial resuscitation, modest pharmacotherapy and nursing care. This review examines the role of surgery in spinal cord injury. The pathophysiology of spinal cord injury is reviewed. The compelling animal data for early decompression is discussed as well as evidence for improved neurological outcome with early decompression in humans. Finally, the impact of early surgery on non-neurological outcome and overall complication rates is examined with the concept of "damage control" discussed with relevance to spinal cord injury. It appears that favourable outcomes are achieved with early surgery, with reduced morbidity/mortality, but definitive data is still pending.

Artificial cervical disc replacement: Principles, types and techniques

Cervical arthroplasty after anterior decompression with insertion of a prosthetic total disc replacement has been suggested as an alternate to anterior cervical fusion. Currently there are four cervical arthroplasty devices available on the market whose results in clinical use have been reported. Each device varies in terms of materials, range of motion, insertion technique and constraint. It is not known which device is ideal. Early studies suggest that in the short term, the complication rate and efficacy is no worse than fusion surgery. Long-term results have not yet been reported. This review examines the current prostheses available on the market as well as discussing issues regarding indications and technique. Pitfalls are discussed and early experiences reviewed. In time, it is hoped that a refinement of cervical arthroplasty occurs in terms of both materials and design as well as in terms of indications and clinical outcomes as spinal surgeons enter a new era of the management of cervical spine disease.

RNA association defines a functionally conserved domain in the nuclear pore protein Nup153

Traffic between the nucleus and cytoplasm takes place through a macromolecular structure termed the nuclear pore complex. To understand how the vital process of nucleocytoplasmic transport occurs, the contribution of individual pore proteins must be elucidated. One such protein, the nucleoporin Nup153, is localized to the nuclear basket of the pore complex and has been shown to be a central component of the nuclear transport machinery. Perturbation of Nup153 function was demonstrated previously to block the export of several classes of RNA cargo. Moreover, these studies also showed that Nup153 can stably associate with RNA in vitro. In this study, we have mapped a domain within Nup153, encompassing amino acids 250-400 in human Nup153, that is responsible for RNA association. After cloning this region of Xenopus Nup153, we performed a cross-species analysis. Despite variation in sequence conservation between Drosophila, Xenopus, and human, this domain of Nup153 displayed robust RNA binding activity in each case, indicating that this property is a hallmark feature of Nup153 and pointing toward a subset of amino acid residues that are key to conferring this ability. We have further determined that a recombinant fragment of Nup153 can bind directly to RNA and that this fragment can interact with endogenous RNA targets. Our findings identify a functionally conserved domain in Nup153 and suggest a role for RNA binding in Nup153 function at the nuclear pore.

The phosphoprotein Op18/stathmin is differentially expressed in ovarian cancer

To identify potential prognostic indicators of ovarian cancer and identify targets for therapeutic strategies, mRNA differential display was used to analyze gene expression differences in normal, benign, and cancerous ovarian tissue. One cDNA isolated by this technique, Op18/stathmin, is a highly conserved gene that is reported to have many different functions within a cell, including signal transduction, control of the cell cycle, and the regulation of microtubules. Quantitative Northern blot analysis of 12 malignant ovarian samples, 8 benign ovarian tumors, and 10 normal ovarian tissue samples demonstrated overexpression of Op18/stathmin mRNA in the malignant cancers. Immunohistochemistry showed an apparent overexpression of Op18/stathmin protein level and an association with proliferating cells.

EMS1 gene expression in primary breast cancer: relationship to cyclin D1 and oestrogen receptor expression and patient survival

The EMS1 and CCND1 genes at chromosome 11q13 are amplified in about 15% of primary breast cancers but appear to confer different phenotypes in ER positive and ER negative tumours. Since there are no published data on EMS1 expression in large series of breast cancers we examined the relationship of EMS1 expression with EMS1 gene copy number and expression of mRNAs for cyclin D1 and ER. In a subset of 129 patients, where matched tumour RNA and DNA was available, EMS1 mRNA overexpression was associated predominantly with gene amplification (P = 0.0061), whereas cyclin D1 mRNA overexpression was not (P = 0.3142). In a more extensive series of 351 breast cancers, there was no correlation between cyclin D1 and EMS1 expression in the EMS1 and cyclin D1 overexpressors (P = 0.3503). Although an association between EMS1 mRNA expression and ER positivity was evident (P = 0.0232), when the samples were divided into quartiles of EMS1 or cyclin D1 mRNA expression, the increase in the proportion of ER positive tumours in the ascending EMS1 mRNA quartiles was not statistically significant (P = 0.0951). In marked contrast there was a significant stepwise increase in ER positivity in ascending quartiles of cyclin D1 mRNA (P = 0.030). A potential explanation for this difference was provided by the observation that in ER positive breast cancer cells oestradiol treatment resulted in increased cyclin D1 gene expression but was without effect on EMS1. The relationship between EMS1 expression and clinical outcome was examined in a subset of 234 patients with median follow-up of 74 months. High EMS1 expression was associated with age > 50 years (P = 0.0001), postmenopausal status (P = 0.0008), lymph node negativity (P = 0.019) and an apparent trend for worse prognosis in the ER negative subgroup. These data demonstrate that overexpression of EMS1 mRNA is largely due to EMS1 gene amplification, is independent of cyclin D1 and ER expression and, in contrast to cyclin D1, is not regulated by oestrogen. Independent overexpression of these genes may confer different phenotypes and disease outcomes in breast cancer as has been inferred from recent studies of EMS1 and CCND1 gene amplification.

An organization-wide approach for an effective communication system, Part 2

This is the second article in a two-part series that describes an organization's approach to designing, implementing, and evaluating a communication system. Part 1 of this series, published in the March 1998 issue, focused on the design and implementation of this system. This article addresses the evaluation of outcomes related to identified goals to improve communication flow and decision making on multiple levels and to promote accountability for clinical and operational performance. Implementation strategies involving change management, emergence of issues with related implications, and planned evolution of this system also are discussed for ongoing organizational performance improvement.

An organization-wide approach for an effective communication system, Part 1

This two-part series provides a cogent discussion of designing and implementing an effective communication system, with a committee structure based on the Joint Commission on Accreditation of Health Care Organizations (JCAHO) functions. Part one includes the development and design using a systems approach. Part two, which will be published in the April 1998 issue of JONA, will address the evaluation of outcomes and implications of this communication system. The experiential learning gained from this process is illustrated by the analysis of themes that surfaced during the implementation.

Authoritarianism among medicine and law students

This study assessed the effects of gender, faculty, and year (level) on "authoritarianism" among university students within the faculties of law and medicine. A questionnaire, using the Ray Adapted F Scale to measure authoritarianism, was administered to 454 students at the University of Western Australia. The first, third and sixth year medical students were compared with first, third and final year law students. Gender alone was responsible for a significant source of variance, with males more authoritarian than females. Faculty alone showed a strong trend towards significance with medicine more authoritarian than law. Although no other 2- or 3- way interactions were significant a trend was apparent in which females became more and males less authoritarian with increasing level.

Suicide and related deaths in Victorian doctors

A cohort of University of Melbourne medical graduates (1950-1959 graduates inclusive) was followed up until December 31, 1986. Vital status at the end of the study period was ascertained and, for those who had died, cause of death was determined. The cohort consisted of 1453 members (1279 men and 174 women). One hundred and twenty-six of the group had died (115 men and 11 women) and 68 (4.7%; 57 men and 11 women) were lost to follow-up. The major causes of death were cardiovascular disease and malignant neoplasms. The standardised mortality ratios (SMRs) for all-cause mortality were low (59 for the male doctors and 84 for the female doctors) indicating that male doctors experience a "force of mortality" 59% that of the general population and female doctors 84%. For the male doctors, the SMR for suicide was 113 (95% confidence interval [CI], 54-207) (10 of 115 deaths in male doctors) about double the SMR for mortality from all causes. For the female doctors, the SMR for suicide was 501 (95% CI, 103-1500) (3 of 11 deaths in female doctors). For deaths resulting from all accidents the SMR was low for the males (29) and higher for the females (126). The SMR for mental disorders for the male doctors was marginally raised (132). This study reveals some indication of a problem in doctors in regard to deaths by suicide, other violent deaths and mental disorders. A larger study involving a control group of equivalent social class is required to confirm the findings of this study.

Practice guidelines and their role in quality assurance and cost effectiveness

In a political and economic context, a basic goal of health care is: appropriate outcomes from appropriate services for appropriate costs in the context of a societal agreement on resources available. One way that the issue of appropriate medical services may be approached is through guidelines established by professional societies. The work of the American College of Physicians (ACP) in its Clinical Efficacy Assessment Project (CEAP) and its development of guidelines is described. In order that guidelines be effective and that practice behavior be modified to conform more to data on effectiveness and less to habit, four components are necessary: valid information from a credible source backed by an incentive within a receptive environment. Each of these components is described.

Integrating practice guidelines with financial incentives

Practice guidelines, in whatever form, hold significant implications for the delivery and the financing of health care. Hence, great care must be taken in developing them. They must be scientifically sound and thus defensible. They must incorporate clinical perspectives and consider patients' preferences. They must cover appropriate as well as inappropriate services. They must foster creation and adoption of a rational payment system. What guidelines, in their best form, can do is enable physicians, faced with an overwhelming array of often conflicting information, to reduce some of the uncertainty they must cope with and to practice the most clinically effective medicine. For physicians to do so requires valid information from a credible source, most often in conjunction with appropriate financial incentives.

Postnatal depression and psychosis--a mother and baby unit in a general hospital

The experience of a Mother and Baby Unit in a General Hospital Psychiatry Department in managing postnatal depression and puerperal psychosis over a 2-year period is reviewed. In our community severe depressive illness will more often be referred to a Public General Hospital with a psychiatric service. The mean admission duration of 26 days for depressive illness was significantly lower than that previously reported by a Psychiatric Hospital. A significant delay in presentation appeared in half the cases, which could be reduced by attention to the family and past psychiatric history, especially the patient's relationship to her own mother indicating risk of puerperal mental disturbance.

The Clinical Efficacy Assessment Project of the American College of Physicians

Throughout the history of the development and use of medical technologies (phar-maceuticals, laboratory tests, invasive and noninvasive procedures, and medical devices), physicians and their patients have been the primary assessors of a technology's worth. If a drug, test, or procedure produces consistent beneficial effects, with little or no risk, then such a technology is commonly added to the clinician's arsenal of weapons against illness and disease. Academic researchers, however, with their keen desires to find new and better ways to diagnose, treat, and cure, are relied upon to produce evidence documenting a technology's efficacy. Others engaged in technology assessment activities—from their own perspectives—include manufacturers, who produce data showing the value of the products they hope to sell; hospitals that wish to make cost-effective purchases; and government agencies, with mandates to protect the public and to spend public dollars wisely. Still, it is the practicing physician who ultimately judges a technology's value based upon its use in individual clinical situations. Until very recently, with the apparent adequacy of these evaluative methods, medical professional societies were not required to enter the technology assessment arena.

A case of personation

A case from the 19th century is described. The patient was admitted to hospital as a man but was revealed to be a woman. The woman's history is examined and the psychological implications of her impersonation are discussed. A hypothetical diagnosis of transsexualism is made.