Activation of the Ah receptor signaling pathway by prostaglandins

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that mediates many of the biological and toxicological actions of a diverse range of chemicals, including the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin). Although no endogenous physiological ligand for the AhR has yet been described, numerous studies support the existence of such a ligand(s). Here we have examined the ability of prostaglandins and related chemicals to activate the AhR signaling system. Using two AhR-based bioassay systems we report that relatively high concentrations of several prostaglandins (namely, PGB3, PGD3, PGF3alpha, PGG2, PGH1, and PGH2) can not only stimulate AhR transformation and DNA binding in vitro, but also induce AhR-dependent reporter gene expression in mouse hepatoma cells in culture. PGG2 also induced AhR-dependent reporter gene expression to a level three-to four fold greater than that observed with a maximal inducing dose of TCDD. Sucrose gradient ligand binding analysis revealed that PGG2 could competitively displace [3H]TCDD from the AhR. Overall, our results demonstrate that selected prostaglandins are weak agonists for the AhR and they represent a structurally distinct and novel class of activator of the AhR signal transduction pathway.

[Hypocretin (orexin) deficiency in narcolepsy-cataplexy]

A mutation in the HCRT locus was proved in 18-yrs old male suffering from narcolepsy-cataplexy. He has demonstrated cataplectic attacks (brief spells of head dropping provoked by laughter) as well as imperative sleep in spells of several minutes up to one hour since the age of six months. He has suffered from severe bulimia since five years; later hypnagogic hallucinations, sleep paralysis and unquiet nocturnal sleep accompanied by periodic limb movements appeared. Symptoms are partially controlled with methylphenidate and either imipramine, clomipramine or fluoxetine. Periodic leg movements poorly responded to L-DOPA and clonazepam treatment. He is HLA-DQB1*0602 negative. Repeated MSLT (over 16 years followed-up period) showed extremely short latency with predominant SOREMPs and also nocturnal PSG recordings revealed fragmented sleep with SOREMPs. This case report demonstrates that hypocretin (orexin) mutations in human can produce the full narcolepsy phenotype and validates data recently reported in dog and mouse models suggesting a role for hypocretin (orexin) in the pathophysiology of narcolepsy and the regulation of REM sleep.

Single nucleotide polymorphisms in multiple novel thrombospondin genes may be associated with familial premature myocardial infarction

BACKGROUND

Recent advances in high-throughput genomics technology have expanded our ability to catalogue allelic variants in large sets of candidate genes related to premature coronary artery disease.

METHODS AND RESULTS

A total of 398 families were identified in 15 participating medical centers; they fulfilled the criteria of myocardial infarction, revascularization, or a significant coronary artery lesion diagnosed before 45 years in men or 50 years in women. A total of 62 vascular biology genes and 72 single-nucleotide polymorphisms were assessed. Previously undescribed variants in 3 related members of the thrombospondin protein family were prominent among a small set of single-nucleotide polymorphisms that showed a statistical association with premature coronary artery disease. A missense variant of thrombospondin 4 (A387P) showed the strongest association, with an adjusted odds ratio for myocardial infarction of 1.89 (P=0.002 adjusted for covariates) for individuals carrying the P allele. A variant in the 3' untranslated region of thrombospondin-2 (change of thymidine to guanine) seemed to have a protective effect against myocardial in individuals homozygous for the variant (adjusted odds ratio of 0.31; P=0.0018). A missense variant in thrombospondin-1 (N700S) was associated with an adjusted odds ratio for coronary artery disease of 11.90 (P=0.041) in homozygous individuals, who also had the lowest level of thrombospondin-1 by plasma assay (P=0.0019).

CONCLUSIONS

This large-scale genetic study has identified the potential of multiple novel variants in the thrombospondin gene family to be associated with familial premature myocardial infarction. Notwithstanding multiple caveats, thrombospondins specifically and high-throughput genomic technology in general deserve further study in familial ischemic heart disease.

Relative contribution of mental health and exercise-related pain increment to treadmill test intolerance in patients with chronic low back pain

STUDY DESIGN

A cross-sectional study.

OBJECTIVES

To determine the relative contribution of pain increase and mental health to testing performance during a single bout of exercise in patients with chronic low back pain.

BACKGROUND

Controversy exists as to which factors principally limit physical performance in patients with chronic low back pain. Some believe psychological factors limit physical performance, whereas others believe activity-related increases in pain intensity limit performance.

METHODS

Seventy-five patients with chronic low back pain reported pain intensity before and after undergoing a maximal, symptom-limited modified treadmill test. Walking time (in minutes) and aerobic fitness were measured. The Short Form 36 Health Survey was administered to all patients.

RESULTS

Fifty-four percent of the sample stopped testing because of a significant increase in pain intensity (P = 0.0001). Treadmill performance was lower in patients who stopped because of pain than in those who stopped because of fatigue (P = 0.02). The patients who stopped because of pain were also more likely to have low mental health as assessed by the Short Form 36 Health Survey. Low mental health, however, did not have a statistically significant influence on treadmill performance.

CONCLUSION

The data indicate that impairment of physical performance during treadmill testing in patients with chronic low back pain is attributable to testing-induced increase in pain intensity rather than to individual low mental health scores.

Global alterations in mechanical function in healed reperfused first anterior myocardial infarction

Two-dimensional analysis techniques were applied to breathhold magnetic resonance (MR) tagged images in humans to better understand left ventricular (LV) mechanics 8 weeks after large reperfused first anterior myocardial infarction (MI). Eighteen patients (aged 51 +/- 13 yr, 15 men) were studied 8 +/- 1 weeks after first anterior MI as were 9 volunteers, (aged 30 +/- 3, 7 men). Breathhold MR myocardial tagging was performed with short-axis images spanning the LV from apex to base. Myocardial deformation was analyzed from apical, mid-LV, and basal slices using two-dimensional analytic techniques and expressed as L1 (greatest systolic lengthening), L2 (greatest systolic shortening), and beta (angular deviation of L1 from the radial direction). LV ejection fraction (EF) by MR imaging in the patients after MI was 45 +/- 15%. The apex and midventricle in patients demonstrated reduced L1 and L2 and increased beta compared with normal subjects with the greatest abnormalities at the apex, as expected in anterior infarction. However, in addition, basal L1 was lower than normal subjects (10 +/- 6% versus 19 +/- 7%, p < 0.0001) as was L2 (14 +/- 7% versus 17 +/- 6%, p < 0.04). Beta was greater than normal at the base (23 +/- 20 degrees and 14 +/- 10 degrees, p < 0.02). L2 correlated significantly with EF in the patient group (EF = 2.6 x L2 + 7, r = 0.68, p < 0.002). After healing of reperfused first anterior MI, maximal lengthening and maximal shortening and the orientation of maximal strains are abnormal throughout the left ventricle, including mild abnormalities at the base. This suggests more diffuse abnormalities in regional mechanical function than simply within the zone of healed infarction.

A guide to undertaking a literature review

BACKGROUND

The National Information Service of the General Practice Evaluation Program (GPEP) produced publications relating to research undertaken under the auspices of the program with the view to adding value to such research. Two anthologies of literature reviews from GPEP research have been produced, one in 1998 and the other in 2000. A thorough guide to undertaking and writing a literature review was part of the second anthology. This paper is a shortened version of that guide.

OBJECTIVE

This paper is designed as an overview for general practitioners who wish to undertake a research project. In this overview the authors describe the reasons researchers undertake a literature review and the steps involved in conducting and writing up a review, including the development of search strategies.

DISCUSSION

The literature review described in this paper is a narrative review. This type of review involves performing thorough literature searches, describing how these were done, grouping findings according to themes, critically discussing findings and placing the proposed research in context.

Age-associated changes in regional aortic pulse wave velocity

OBJECTIVES

This study was designed to determine noninvasively the age-associated changes in regional mechanical properties in normals using phase-contrast magnetic resonance imaging (PCMRI).

BACKGROUND

It has been well documented that there is a progressive increase in aortic pulse wave velocity (PWV) with age. Previously, PWV has been measured at a single aortic location, or has compared arterial waves between carotid and femoral points to determine PWV.

METHODS

Applanation tonometry (TONO) and in-plane PCMR was performed in 24 volunteers (12 men) ranging in age from 21 to 72 years old. The PCMRI PWV was measured in three aortic segments. As validation, TONO was performed to determine PWV between the carotid and femoral artery.

RESULTS

When PCMRI PWV was averaged over the three locations, it was not different from TONO (7.9 +/- 2.3 vs. 7.6 +/- 2.4 m/s, respectively). When the volunteers were divided into groups of < 55 and > or =55 years old, the younger group showed similar PWV at each aortic location. However, the older group displayed significantly increased PWV in the region spanning the ascending and proximal descending aorta compared with the mid-thoracic or abdominal segments (10.6 +/- 2.5 m/s, 9.2 +/- 2.8 m/s, and 7.1 +/- 1.7 m/s, respectively, p < 0.001, analysis of variance).

CONCLUSIONS

In-plane PCMRI permits determination of PWV in multiple aortic locations in a single acquisition. Progressive fragmentation of elastic fibers and alterations in the regulation of vascular tone may result in an age-related, regional increase in PWV primarily affecting the proximal aorta.

Underutilization of reperfusion therapy in eligible African Americans with acute myocardial infarction: Role of presentation and evaluation characteristics

BACKGROUND

Immediate reperfusion therapy to restore coronary blood flow is recommended for all eligible patients with acute myocardial infarction. However, reperfusion therapy is reportedly underutilized among African Americans, even when they are eligible. Reasons for the lack of use have not been fully explored.

METHODS

We examined the demographic, clinical, and treatment data of 10,469 African Americans with acute myocardial infarction who were eligible for reperfusion therapy, enrolled in the National Registry of Myocardial Infarction-2 from June 1994 through March 1998.

RESULTS

The mean age was 62.58 (+/-14.4) years, and 44.7% were female. Although eligible, 47% of the African Americans in this study did not receive reperfusion therapy. In a multivariate analysis, the absence of chest pain at presentation (odds ratio [OR] 0.31, 95% CI 0.26-0.37) and initial admission diagnoses other than definite myocardial infarction (OR for receipt of reperfusion <0.12) were the strongest predictors of lack of early reperfusion therapy. Progressive delays in hospital arrival and hospital evaluation predicted a lower likelihood of early reperfusion. Prior stroke (OR 0.63, 95% CI 0.50-0.78), myocardial infarction (OR 0.75, 95% CI 0.65-0.86), and congestive heart failure (OR 0.49, 95% CI 0.40-0.60) were all associated with lack of reperfusion therapy.

CONCLUSION

Almost half of eligible African American patients with myocardial infarction did not receive reperfusion therapy. Potential reasons may include atypical presentation, patient and institutional delay, and underappreciation of myocardial infarction by care providers. Strategies to address these factors may improve the rate of use of reperfusion therapy.

Diagnostic, prognostic, and cost assessment of coronary artery disease in women

Women with obstructive coronary disease appear to be more challenging diagnostically and suffer a more adverse prognosis than men. More than one half of women with symptoms of ischemic heart disease have no obstructive coronary artery disease at coronary angiography, yet these women frequently have persistent symptom-related disability and consume large amounts of healthcare resources. Prior evidence has been limited regarding effective diagnostic strategies for the assessment of symptomatic women. The current report synthesizes existing evidence on diagnostic testing in women, including research from the ongoing National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) study. In addition to recent published evidence (drawn from much larger cohorts of women) that stress echocardiography and nuclear imaging are similar in their ability to risk-stratify women, the WISE study is exploring new pathophysiological mechanisms of microvascular dysfunction in women. An unfolding body of evidence suggests that as tests become more diagnostically and prognostically accurate, the process will become more cost efficient. The results from a growing number of large observational series and National Institutes of Health-sponsored studies are expected to be the foundation for cost-effective diagnostic and prognostic strategies for the approximately 5 million women who undergo evaluation for coronary disease annually.

Absence of adverse outcomes after magnetic resonance imaging early after stent placement for acute myocardial infarction: a preliminary study

Previous studies have documented the safety of magnetic resonance imaging (MRI) of stents in vitro, when placed in animals in vivo, and in patients after elective stent placement. The safety of imaging patients' with stents early after myocardial infarction (MI) has not been examined. We studied 13 patients in an MRI study of myocardial viability on day 3 +/- 1 after stent placement for acute MI. No patient had any clinical events in the early post-MI period, and only 1 of 13 patients demonstrated in-stent restenosis with a mean follow-up of 7 +/- 2 months. For comparison, a group of 17 patients studied concurrently at Allegheny General Hospital as part of the Stent PAMI study, without undergoing MRI, suffered two early deaths and three episodes of in-stent restenosis within 6 months. Based on a review of the literature and this preliminary study, recent stent placement for acute MI should not be considered a contraindication to MRI.

Health status and satisfaction with health care: a longitudinal study among patients served by the Veterans Health Administration

As the Veterans Health Administration (VHA) places high priority on becoming a performance-based organization, there is an increasing need to quantify and refine its outcome measurement system. Using panel data from VHA ambulatory care patients (1996-1998), we conducted cross-lagged correlations and ordinary least squares regression to examine the relationship between 2 VHA health care values: health status and satisfaction with care. The study results indicated that patients' health status was significantly associated with their satisfaction with care, indicating that patients with better health status were more likely to be satisfied with health care. Although satisfaction with care was both a consequence and a determinant of health status, the effects of health status on satisfaction seemed to be more important than the effects of satisfaction on health status. More research is needed for a better understanding of the dynamic relationship between health status and satisfaction with care.

Low cerebrospinal fluid hypocretin (Orexin) and altered energy homeostasis in human narcolepsy

Hypocretins (orexins) are hypothalamic neuropeptides involved in sleep and energy homeostasis. Hypocretin mutations produce narcolepsy in animal models. In humans, narcolepsy is rarely due to hypocretin mutations, but this system is deficient in the cerebrospinal fluid (CSF) and brain of a small number of patients. A recent study also indicates increased body mass index (BMI) in narcolepsy. The sensitivity of low CSF hypocretin was examined in 38 successive narcolepsy-cataplexy cases [36 human leukocyte antigen (HLA)-DQB1*0602-positive] and 34 matched controls (15 controls and 19 neurological patients). BMI and CSF leptin levels were also measured. Hypocretin-1 was measurable (169 to 376 pg/ml) in all controls. Levels were unaffected by freezing/thawing or prolonged storage and did not display any concentration gradient. Hypocretin-1 was dramatically decreased (<100 pg/ml) in 32 of 38 patients (all HLA-positive). Four patients had normal levels (2 HLA-negative). Two HLA-positive patients had high levels (609 and 637 pg/ml). CSF leptin and adjusted BMI were significantly higher in patients versus controls. We conclude that the hypocretin ligand is deficient in most cases of human narcolepsy, providing possible diagnostic applications. Increased BMI and leptin indicate altered energy homeostasis. Sleep and energy metabolism are likely to be functionally connected through the hypocretin system.

Health status assessments using the Veterans SF-12 and SF-36: methods for evaluating otucomes in the Veterans Health Administration

This article describes a study in which the administration of two health surveys, the Veterans SF-36 and SF-12, by telephone and mail-out was used to assess the differences in the health surveys' costs and scores by mode of administration and determine which mode was cost-efficient. The study employed a crossover design: after 12 unsuccessful attempts to contact patients by telephone, the patients were administered the survey by mail, and after 2 unsuccessful mail-outs, up to three attempts were made to interview the patients by telephone. The analysis of the data showed that mail administration, with or without crossover to telephone, was more cost-efficient than telephone administration, having both lower average total and variable costs per completed questionnaire. Overall, telephone administration was about 30% more expensive that mail administration, primarily due to the cost of labor. The marginal cost of an additional completed Veterans SF-12 or Veterans SF-36 was also substantially lower for mail administration. Mail administration without crossover to telephone administration was the most cost-efficient strategy for administering both the Veterans SF-12 and SF-36. The results of this study strongly suggest the need to consider the mode of administration if questionnaires like the Veterans SF-12 or SF-36 are to be used to assess health outcomes within and across large health care systems.

Combined angiotensin II receptor antagonism and angiotensin-converting enzyme inhibition further attenuates postinfarction left ventricular remodeling

BACKGROUND

ACE inhibition (ACEI) attenuates post-myocardial infarction (MI) LV remodeling, but the effects of angiotensin II type 1 receptor (AT(1)) antagonism alone or in combination with ACEI are unclear. Accordingly, we investigated the effects of AT(1) antagonism, ACEI, and their combination in a well-characterized ovine postinfarction model.

METHODS AND RESULTS

Beginning 2 days after transmural anteroapical MI, 62 sheep were treated with 1 of 5 treatment regimens: no therapy (control, n=12), standard-dose ACEI (sACEI; ramipril 10 mg/d, n=14), high-dose ACEI (hACEI; ramipril 20 mg/d, n=8), AT(1) blockade (losartan 50 mg/d, n=13), and combination therapy with sACEI+AT(1) blockade (CT; ramipril 10 mg/d+losartan 50 mg/d, n=15). MRI was performed before and 8 weeks after MI to quantify changes in LV end-diastolic and end-systolic volume indices (DeltaEDVI, DeltaESVI) and ejection fraction (DeltaEF). Change in regional percent intramyocardial circumferential shortening in noninfarcted segments adjacent to the infarct (Adj Delta%S) was measured by tagged MRI. CT resulted in the most marked blunting of LV remodeling: DeltaESVI (+1.0+/-0.4, +0.7+/-0.4, +0.6+/-0.3, +0.9+/-0.5, and +0.4+/-0.2* mL/kg); DeltaEDVI (+0.9+/-0.4, +0.7+/-0.5, +0.6+/-0.5, +0.9+/-0.5, and +0.4+/-0.3 mL/kg); DeltaEF (-24+/-7, -18+/-6, -14+/-7, -18+/-10, and -11+/-9* %); and Adj Delta%S (-8+/-4, -7+/-3, -5+/-3, -5+/-3, and -2+/-3* %) for Control, sACEI, hACEI, AT(1) blockade, and CT, respectively (*P<0.04 versus sACEI, AT(1) blockade, and control; P<0.05 versus control; P<0.002 versus AT(1) blockade and control). EDVI and ESVI at 8 weeks after MI were smallest with CT (P<0.02 versus all).

CONCLUSIONS

Combination therapy with sACEI+AT(1) blockade shows promise in attenuating postinfarction LV remodeling but was not clearly superior to hACEI in the present study.

Advancing health promotion in Australian general practice

Health promotion activities, while having the potential to prevent disease and decrease the burden of ill health, often play a minor role in the health care offered by general practitioners. There are several identified barriers to the involvement of Australian general practitioners in health promotion. These include structural barriers and barriers within the practice setting, individual practitioner and patient factors, and difficulties in evaluating the outcomes of health promotion activities. This article explores the barriers to the engagement of Australian general practice with health promotion and reviews several recent initiatives that have the potential to increase the health promotion activities of general practitioners. These initiatives act at the level of the individual practitioner, the practice, and in the community. Despite the lack of a coordinated national approach, these strategies form an important development in general practice.

Molecular and biochemical characterization of endo-beta-mannanases from germinating coffee (Coffea arabica) grains

The activity of endo-beta-mannanase ([1-->4]-beta-mannan endohydrolase EC 3.2.1.78) is likely to be central to the metabolism of cell wall mannans during the germination of grains of coffee (Coffea spp.). In the present paper, we report the cloning and sequencing of two endo-beta-mannanase cDNAs (manA and manB) by different strategies from Coffea arabica L.. The manA cDNA was obtained by the use of oligonucleotides homologous to published sequences of other endo-beta-mannanases and manB by the use of oligonucleotides deduced from a purified enzyme from coffee. ManA and B proteins share about 56% sequence homology and include highly conserved regions found in other mannan endohydrolases. Purification of the activity by chromatography followed by separation by two-dimensional electrophoresis and amino acid sequencing demonstrated the existence of at least seven isomers of the ManB form. The existence of multiple manB genes was also indicated by Southern analysis, whereas only one or two gene copies were detected for manA. Northern hybridizations with manA- and manB-specific probes showed that mRNA transcripts for both cDNAs were present at the same periods of bean germination with transcript peaks at 20 days after imbibition of water (DAI). Transcripts were not detected during grain maturation or in the other tissues such as roots, stems, flowers and leaves. The peak endo-beta-mannanase activity occurred at approximately 28 DAI and was not detected in grains prior to imbibition. Activity and mRNA levels appeared to be tightly co-ordinated. Tests of substrate specificity with the purified ManB enzyme showed that activity required a minimum of five mannose units to function efficiently.

Coronary microvascular dysfunction is highly prevalent in women with chest pain in the absence of coronary artery disease: results from the NHLBI WISE study

BACKGROUND

Chest pain in the absence of obstructive coronary artery disease (CAD) is common in women; it is frequently associated with debilitating symptoms and repeated evaluations and may be caused by coronary microvascular dysfunction. However, the prevalence and determinants of microvascular dysfunction in these women are uncertain.

METHODS

We measured coronary flow velocity reserve (coronary velocity response to intracoronary adenosine) to evaluate the coronary microvasculature and risk factors for atherosclerosis in 159 women (mean age, 52.9 years) with chest pain and no obstructive CAD. All women were referred for coronary angiography to evaluate their chest pain as part of the Women's Ischemia Syndrome Evaluation (WISE) study.

RESULTS

Seventy-four (47%) women had subnormal (<2.5) coronary flow velocity reserve suggestive of microvascular dysfunction (mean, 2.02 +/- 0.38); 85 (53%) had normal reserve (mean, 3.13 +/- 0.64). Demographic characteristics, blood pressure, ventricular function, lipid levels, and reproductive hormone levels were not significantly different between women with normal and those with abnormal microvascular function. Postmenopausal hormone use within 3 months was significantly less prevalent among those with microvascular dysfunction (40% vs 60%, P =.032). Age and number of years past menopause correlated with flow velocity reserve (r = -0.18, P =.02, and r = -0.30, P <.001, respectively). No significant associations were identified between flow velocity reserve and lipid and hormone levels, blood pressure, and left ventricular ejection fraction.

CONCLUSIONS

Coronary microvascular dysfunction is present in approximately one half of women with chest pain in the absence of obstructive CAD and cannot be predicted by risk factors for atherosclerosis and hormone levels. Therefore, the diagnosis of coronary microvascular dysfunction should be considered in women with chest pain not attributable to obstructive CAD.

Physical and radiation hybrid mapping of canine chromosome 12, in a region corresponding to human chromosome 6p12-q12

The positional cloning of the hypocretin receptor 2, the gene for autosomal recessive canine narcolepsy, has led to the development of a physical map spanning a large portion of canine chromosome 12 (CFA12), in a region corresponding to human chromosome 6p12-q13. More than 40 expressed sequence tags (ESTs) were used in homology search experiments, together with chromosome walking, to build both physical and radiation hybrid maps of the CFA12 13-21 region. The resulting map of bacterial artificial chromosome ends, ESTs, and microsatellite markers represents the longest continuous high-density map of the dog genome reported to date. These data further establish the dog as a system for studying disease genes of interest to human populations and highlight feasible approaches for positional cloning of disease genes in organisms where genomic resources are limited.

Detailed angiographic analysis of women with suspected ischemic chest pain (pilot phase data from the NHLBI-sponsored Women's Ischemia Syndrome Evaluation [WISE] Study Angiographic Core Laboratory)

The purpose of this study is to provide a contemporary qualitative and quantitative analysis of coronary angiograms from a large series of women enrolled in the Women's Ischemia Syndrome Evaluation (WISE) study who had suspected ischemic chest pain. Previous studies have suggested that women with chest pain have a lower prevalence of significant coronary artery disease (CAD) compared with men. Detailed analyses of angiographic findings relative to risk factors and outcomes are not available. All coronary angiograms were reviewed in a central core laboratory. Quantitative measurement of percent stenosis was used to assess the presence and severity of disease. Of the 323 women enrolled in the pilot phase, 34% had no detectable, 23% had measurable but minimal, and 43% had significant ( > 50% diameter stenosis) CAD. Of those with significant CAD, most had multivessel disease. Features suggesting complex plaque were identified in < 10%. Age, hypertension, diabetes mellitus, prior myocardial infarction (MI), current hormone replacement therapy, and unstable angina were all significant, independent predictors of presence of significant disease (p < 0.05). Subsequent hospitalization for a cardiac cause occurred more frequently in those women with minimal and significant disease compared with no disease (p = 0.001). The common findings of no and extensive CAD among symptomatic women at coronary angiography highlight the need for better clinical noninvasive evaluations for ischemia. Women with minimal CAD have intermediate rates of rehospitalization and cardiovascular events, and thus should not be considered low risk.

Early tPA treatment and aeromedical transport of patients with acute myocardial infarction

Over a 2-year period 192 patients with acute myocardial infarction (AMI) were transported by helicopter and treated with recombinant tissue-plasminogen activator (tPA). All patients were entered into the Thrombolysis in Myocardial Infarction-Phase II (TIMI II) trial. Eighty-two of these patients were treated with tPA after aeromedical transport to a tertiary care center. One hundred ten patients had tPA treatment initiated by the flight crew prior to transport. The flight crews initiated therapy 28 +/- 11 minutes after arrival at the sending hospital. The post-flight treated patients received the tPA bolus 82 +/- 20 minutes after arrival at the sending hospital (P less than .0001), and 41 +/- 18 minutes after arrival at the receiving hospital (P less than .0001). Based on enzyme and electrocardiographic changes, all patients in the study had a confirmed diagnosis of AMI before discharge. Patients with inferior myocardial infarction (MI) treated with tPA in-flight were more likely to suffer from bradycardia and hypotension requiring atropine injection during transport than the post-flight treated patients or in-flight treated patients with anterior MI. There was no in-flight mortality in either group. Our experience indicates that patients with AMI can be transported safely during tPA therapy. Also, a trained team whose sole responsibility is the early evaluation and initiation of therapy in a patient with AMI can function as accurately and significantly more rapidly than tertiary care emergency department and ICU personnel following identical protocols.

Adiabatic calorimetric decomposition studies of 50 wt.% hydroxylamine/water

Calorimetric data can provide a basis for determining potential hazards in reactions, storage, and transportation of process chemicals. This work provides calorimetric data for the thermal decomposition behavior in air of 50wt.% hydroxylamine/water (HA), both with and without added stabilizers, which was measured in closed cells with an automatic pressure tracking adiabatic calorimeter (APTAC). Among the data provided are onset temperatures, reaction order, activation energies, pressures of noncondensable products, thermal stability at 100 degrees C, and the effect of HA storage time. Discussed also are the catalytic effects of carbon steel, stainless steel, stainless steel with silica coating, inconel, titanium, and titanium with silica coating on the reaction self-heat rates and onset temperatures. In borosilicate glass cells, HA was relatively stable at temperatures up to 133 degrees C, where the HA decomposition self-heat rate reached 0.05 degrees C/min. The added stabilizers appeared to reduce HA decomposition rates in glass cells and at ambient temperatures. The tested metals and metal surfaces coated with silica acted as catalysts to lower the onset temperatures and increase the self-heat rates.

Psychosocial variables are associated with atherosclerosis risk factors among women with chest pain: the WISE study

OBJECTIVE

We investigated associations between atherosclerosis risk factors (smoking behavior, serum cholesterol, hypertension, body mass index, and functional capacity) and psychological characteristics with suspected linkages to coronary disease (depression, hostility, and anger expression) in an exclusively female cohort.

METHODS

Six hundred eighty-eight middle-aged women with chest pain warranting clinical investigation completed a comprehensive diagnostic protocol that included quantitative coronary angiography to assess coronary artery disease (CAD). Primary analyses controlled for menopausal status, age, and socioeconomic status variables (income and education).

RESULTS

High depression scores were associated with a nearly three-fold risk of smoking (odds ratio (OR) = 2.8, 95% confidence interval (CI) = 1.4-5.7) after covariate adjustment, and women reporting higher depression symptoms were approximately four times more likely to describe themselves in the lowest category of functional capacity (OR = 3.7, 95% CI = 1.7-7.8). High anger-out scores were associated with a four-fold or greater risk of low high-density lipoprotein cholesterol concentration (<50 mg/dl; OR = 4.0, 95% CI = 1.4-11.1) and high low-density lipoprotein cholesterol concentration (>160 mg/dl; OR = 4.8, 95% CI = 1.5-15.7) and a larger body mass index (OR = 3.5, 95% CI = 1.1-10.8) after covariate adjustment.

CONCLUSIONS

These results demonstrate consistent and clinically relevant relationships between psychosocial factors and atherosclerosis risk factors among women and may aid our understanding of the increased mortality risk among women reporting high levels of psychological distress.

Complex HLA-DR and -DQ interactions confer risk of narcolepsy-cataplexy in three ethnic groups

Human narcolepsy-cataplexy, a sleep disorder associated with a centrally mediated hypocretin (orexin) deficiency, is tightly associated with HLA-DQB1*0602. Few studies have investigated the influence that additional HLA class II alleles have on susceptibility to this disease. In this work, 1,087 control subjects and 420 narcoleptic subjects with cataplexy, from three ethnic groups, were HLA typed, and the effects of HLA-DRB1, -DQA1, and -DQB1 were analyzed. As reported elsewhere, almost all narcoleptic subjects were positive for both HLA-DQA1*0102 and -DQB1*0602. A strong predisposing effect was observed in DQB1*0602 homozygotes, across all ethnic groups. Relative risks for narcolepsy were next calculated for heterozygous DQB1*0602/other HLA class II allelic combinations. Nine HLA class II alleles carried in trans with DQB1*0602 were found to influence disease predisposition. Significantly higher relative risks were observed for heterozygote combinations including DQB1*0301, DQA1*06, DRB1*04, DRB1*08, DRB1*11, and DRB1*12. Three alleles-DQB1*0601, DQB1*0501, and DQA1*01 (non-DQA1*0102)-were found to be protective. The genetic contribution of HLA-DQ to narcolepsy susceptibility was also estimated by use of lambda statistics. Results indicate that complex HLA-DR and -DQ interactions contribute to the genetic predisposition to human narcolepsy but that additional susceptibility loci are also most likely involved. Together with the recent hypocretin discoveries, these findings are consistent with an immunologically mediated destruction of hypocretin-containing cells in human narcolepsy-cataplexy.

History of anxiety disorders is associated with a decreased likelihood of angiographic coronary artery disease in women with chest pain: the WISE study

OBJECTIVES

We sought to evaluate the ability of psychiatric anxiety-disorder history to discriminate between women with and without angiographic coronary artery disease (CAD) in a population with chest pain.

BACKGROUND

A total of 435 women with chest pain underwent a diagnostic battery including coronary angiography in order to improve testing guidelines for women with suspected CAD.

METHODS

Women referred for coronary angiography completed questionnaires assessing prior treatment history for anxiety disorder and current anxiety-related symptoms. Analyses controlled for standard CAD risk factors.

RESULTS

Forty-four women (10%) reported receiving prior treatment for an anxiety disorder. This group acknowledged significantly higher levels of autonomic symptoms (e.g., headaches, muscle tension [F = 25.0, p < 0.0011 and higher behavioral avoidance scores (e.g., avoidance of open places or traveling alone by bus [F = 4.2, p < 0.05]) at baseline testing compared with women without prior anxiety problems. Women with an anxiety-disorder history did not differ from those without such a history with respect to the presence of inducible ischemia or use of nitroglycerin, although they were younger and more likely to describe both "tight" and "sharp" chest pain symptoms and to experience back pain and episodes of nocturnal chest pain. Logistic regression results indicated that the positive-anxiety-history group was more likely to be free of underlying significant angiographic CAD (odds ratio = 2.74, 95% confidence interval 1.15 to 6.5, p = 0.03).

CONCLUSIONS

Among women with chest pain symptoms, a history of anxiety disorders is associated with a lower probability of significant angiographic CAD. Knowledge of anxiety disorder history may assist in the clinical evaluation of women with chest pain.