bluuebunny/crossref_metadata_2025 huggingface dataset:
Uppermost Blood Levels of the Right and Left Atria in the Supine Position
Authors: Seo Jeong-Hwa , Jung Chul-Woo , Bahk Jae-Hyon
Published: July 2007

Background

To eliminate the influence of hydrostatic pressure, proper transducer positions for central venous pressure and pulmonary artery wedge pressure are at the uppermost blood levels of right atrium (RA) and left atrium (LA). This study was performed to investigate accurate reference levels of central venous pressure and pulmonary artery wedge pressure in the supine position.

Methods

Chest computed tomography images of 96 patients without history of cardiothoracic surgery, heart disease, or cardiothoracic anatomical abnormality were retrospectively reviewed. The anteroposterior (AP) diameter of the thorax and the vertical distances from the skin on the back to the most anterior portion of RA (RA height) and LA (LA height) were measured. Their ratios were abbreviated, respectively, as RA height/AP diameter and LA height/AP diameter. Data are expressed as mean +/- SD (range).

Results

There was a significant difference [4.6 +/- 1.0 (1.6-6.4) cm; P < 0.001] between RA and LA heights. AP diameter was positively correlated with RA and LA heights (R = 0.839 and 0.700, respectively; P < 0.001). There was also a significant difference between RA height/AP diameter [0.83 +/- 0.03 (0.71-0.91)] and LA height/AP diameter [0.62 +/- 0.04 (0.52-0.72)] (P < 0.001).

Conclusion

In the supine position, a central venous pressure transducer should be positioned approximately 4.6 cm higher than a pulmonary artery wedge pressure transducer. The external reference level for central venous pressure seems to be at approximately four fifths of the AP diameter of the thorax from the back, and that for pulmonary artery wedge pressure seems to be at approximately three fifths of the AP diameter.
Reversal of Rocuronium-induced (1.2 mg/kg) Profound Neuromuscular Block by Sugammadex
Authors: de Boer Hans D. , Driessen Jacques J. , Marcus Marco A. E. , Kerkkamp Hans , Heeringa Marten , Klimek Markus
Published: July 2007

Background

Reversal of rocuronium-induced neuromuscular blockade can be accomplished by chemical encapsulation of rocuronium by sugammadex, a modified gamma-cyclodextrin derivative. This study investigated the efficacy and safety of sugammadex in reversing rocuronium-induced profound neuromuscular blockade at 5 min in American Society of Anesthesiologists physical status I and II patients.

Methods

Forty-five American Society of Anesthesiologists physical status I and II patients (aged 18-64 yr) scheduled to undergo surgical procedures (anticipated anesthesia duration >/= 90 min) were randomly assigned to a phase II, multicenter, assessor-blinded, placebo-controlled, parallel, dose-finding study. Anesthesia was induced and maintained with propofol and an opioid. Profound neuromuscular blockade was induced with 1.2 mg/kg rocuronium bromide. Sugammadex (2.0, 4.0, 8.0, 12.0, or 16.0 mg/kg) or placebo (0.9% saline) was then administered 5 min after the administration of rocuronium. Neuromuscular function was monitored by acceleromyography, using train-of-four nerve stimulation. Recovery time was the time from the start of administration of sugammadex or placebo, to recovery of the train-of-four ratio to 0.9. Safety assessments were performed on the day of the operation and during the postoperative and follow-up period.

Results

A total of 43 patients received either sugammadex or placebo. Increasing doses of sugammadex reduced the mean recovery time from 122 min (spontaneous recovery) to less than 2 min in a dose-dependent manner. Signs of recurrence of blockade were not observed. No serious adverse events related to sugammadex were reported. Two adverse events possibly related to sugammadex were reported in two patients (diarrhea and light anesthesia); however, both patients recovered without sequelae.

Conclusions

Sugammadex rapidly and effectively reversed profound rocuronium-induced neuromuscular blockade in humans and was well tolerated.
Avoidance of Nitrous Oxide for Patients Undergoing Major Surgery
Authors: Myles Paul S. , Leslie Kate , Chan Matthew T. V. , Forbes Andrew , Paech Michael J. , Peyton Philip , Silbert Brendan S. , Pascoe Elaine
Published: July 2007

Background

Nitrous oxide is widely used in anesthesia, often administered at an inspired concentration around 70%. Although nitrous oxide interferes with vitamin B12, folate metabolism, and deoxyribonucleic acid synthesis and prevents the use of high inspired oxygen concentrations, the consequences of these effects are unclear.

Methods

Patients having major surgery expected to last at least 2 h were randomly assigned to nitrous oxide-free (80% oxygen, 20% nitrogen) or nitrous oxide-based (70% N2O, 30% oxygen) anesthesia. Patients and observers were blind to group identity. The primary endpoint was duration of hospital stay. Secondary endpoints included duration of intensive care stay and postoperative complications; the latter included severe nausea and vomiting, and the following major complications: pneumonia, pneumothorax, pulmonary embolism, wound infection, myocardial infarction, venous thromboembolism, stroke, awareness, and death within 30 days of surgery.

Results

Of 3,187 eligible patients, 2,050 consenting patients were recruited. Patients in the nitrous oxide-free group had significantly lower rates of major complications (odds ratio, 0.71; 95% confidence interval, 0.56-0.89; P = 0.003) and severe nausea and vomiting (odds ratio, 0.40; 95% confidence interval, 0.31-0.51; P < 0.001), but median duration of hospital stay did not differ substantially between groups (7.0 vs. 7.1 days; P = 0.06). Among patients admitted to the intensive care unit postoperatively, those in the nitrous oxide-free group were more likely to be discharged from the unit on any given day than those in the nitrous oxide group (hazard ratio, 1.35; 95% confidence interval, 1.05-1.73; P = 0.02).

Conclusions

Avoidance of nitrous oxide and the concomitant increase in inspired oxygen concentration decreases the incidence of complications after major surgery, but does not significantly affect the duration of hospital stay. The routine use of nitrous oxide in patients undergoing major surgery should be questioned.
Incidence of Intraoperative Hypotension as a Function of the Chosen Definition
Authors: Bijker Jilles B. , van Klei Wilton A. , Kappen Teus H. , van Wolfswinkel Leo , Moons Karel G. M. , Kalkman Cor J.
Published: July 2007

Background

Intraoperative hypotension (IOH) is a common side effect of general anesthesia and has been reported to be associated with adverse perioperative outcomes. These associations were found using different definitions for IOH. It is unknown whether the incidences of IOH found with those different definitions are comparable. The authors aimed to describe the relation between the chosen definition and incidence of IOH.

Methods

First, a systematic literature search was performed to identify recent definitions of IOH that have been used in the anesthesia literature. Subsequently, these definitions were applied to a cohort of 15,509 consecutive adult patients undergoing noncardiac surgery during general anesthesia. The incidence of IOH according to the different threshold values was calculated, and the effect of a defined minimal duration of a hypotensive episode was studied.

Results

Many different definitions of IOH were found. When applied to a cohort of patients, these different definitions resulted in different IOH incidences. Any episode of systolic blood pressure below 80 mmHg was found in 41% of the patients, whereas 93% of the patients had at least one episode of systolic blood pressure more than 20% below baseline. Both definitions are frequently used in the literature. The relation between threshold values from the literature and IOH incidence shows an S-shaped cumulative incidence curve, with occurrence frequencies of IOH varying from 5% to 99%.

Conclusions

There is no widely accepted definition of IOH. With varying definitions, many different incidences can be reproduced. This might have implications for previously described associations between IOH and adverse outcomes.
Transesophageal Echocardiography and Cardiovascular Sources of Embolism
Authors: Tan Christine Ngukhoon , Fraser Alan G. , Warltier David C.
Published: July 2007

Transesophageal echocardiography has become an invaluable investigation in patients with cardioembolic events because of its high sensitivity and specificity for defining detailed structure and function of the cardiovascular system. Patients who receive anesthesia and critical care may be at risk of systemic embolism from various cardiovascular sources. The main factors associated with embolism include intracardiac lesions such as thrombi, vegetations, and tumors; cardiac anomalies; and vascular disease, e.g., aortic atheroma. In this review article, the authors describe how transesophageal echocardiography may be used to identify various cardiovascular sources of embolism, provide risk stratification, influence medical therapy, and refine clinical decision making in patients receiving critical care and anesthesia. With these improvements, it is hoped that better patient outcomes may be achieved in the perioperative period.
Immunoglobulin E Antibodies to Rocuronium
Authors: Ebo Didier G. , Venemalm Lennart , Bridts Chris H. , Degerbeck Frederik , Hagberg Hans , De Clerck Luc S. , Stevens Wim J.
Published: July 2007

Background

Diagnosis of allergy from neuromuscular blocking agents is not always straightforward. The objectives of the current study were to investigate the value of quantification of immunoglobulin E (IgE) by ImmunoCAP (Phadia AB, Uppsala, Sweden) in the diagnosis of rocuronium allergy and to study whether IgE inhibition tests can predict clinical cross-reactivity between neuromuscular blocking agents.

Methods

Twenty-five rocuronium-allergic patients and 30 control individuals exposed to rocuronium during uneventful anesthesia were included. Thirty-two sera (total IgE > 1,500 kU/l) were analyzed for potential interference of elevated total IgE titers. Results were compared with quantification of IgE for suxamethonium, morphine, and pholcodine. Cross-reactivity between drugs was assessed by IgE inhibition and skin tests.

Results

Sensitivity of IgE for rocuronium, suxamethonium, morphine, and pholcodine was 68, 60, 88, and 86%, respectively. Specificity was 100% for suxamethonium, morphine, and pholcodine IgE and 93% for rocuronium IgE. ROC analysis between patients and control individuals changed the threshold to 0.13 kUa/l for rocuronium, 0.11 kUa/l for suxamethonium, 0.36 kUa/l for morphine, and 0.43 kUa/l for pholcodine. Corresponding sensitivity was 92, 72, 88, and 86%, respectively. Specificity was unaltered. Interference of elevated total IgE with quantification of IgE was demonstrated by the analysis in sera with a total IgE greater than 1,500 kU/l. IgE inhibition did not predict clinical relevant cross-reactivity.

Conclusions

The rocuronium ImmunoCAP constitutes a reliable technique to diagnose rocuronium allergy, provided an assay-specific decision threshold is applied. IgE assays based on compounds bearing ammonium epitopes are confirmed to represent reliable tools to diagnose rocuronium allergy. High total IgE titers were observed to affect specificity of the assays.
Ejaculatory Pain
Authors: Aasvang Eske K. , Møhl Bo , Kehlet Henrik
Published: July 2007

Background

Sexual dysfunction due to ejaculatory and genital pain after groin hernia surgery may occur in approximately 2.5% of patients. However, the specific psychosexological and neurophysiologic characteristics have not been described, thereby precluding assessment of pathogenic mechanisms and treatment strategies.

Methods

Ten patients with severe pain-related sexual dysfunction and ejaculatory pain were assessed in detail by quantitative sensory testing and interviewed by a psychologist specialized in evaluating sexual functional disorders and were compared with a control group of 20 patients with chronic pain after groin hernia repair but without sexual dysfunction, to identify sensory changes associated with ejaculatory pain.

Results

Quantitative sensory testing showed significantly higher thermal and mechanical detection thresholds and lowered mechanical pain detection thresholds in both groups compared with the nonpainful side. Pressure pain detection threshold and tolerance were significantly lower in the ejaculatory pain group compared with the control group. 'The maximum pain was specifically located at the external inguinal annulus in all ejaculatory pain patients, but not in controls. The psychosexual interview revealed no major psychosexual disturbances and concluded that the pain was of somatic origin. All patients with ejaculatory pain had experienced major negative life changes and deterioration in their overall quality of life and sexual function as a result of the hernia operation.

Conclusions

Postherniotomy ejaculatory pain and pain-related sexual dysfunction is a specific chronic pain state that may be caused by pathology involving the vas deferens and/or nerve damage. Therapeutic strategies should therefore include neuropathic pain treatment and/or surgical exploration.
Thalamic Microinjection of Nicotine Reverses Sevoflurane-induced Loss of Righting Reflex in the Rat
Authors: Alkire Michael T. , McReynolds Jayme R. , Hahn Emily L. , Trivedi Akash N.
Published: July 2007

Background

Neuronal nicotinic acetylcholine receptors are both potently inhibited by anesthetics and densely expressed in the thalamus. Brain imaging shows that thalamic activity suppression accompanies anesthetic-induced unconsciousness. Therefore, anesthetic-induced unconsciousness may involve direct antagonism of thalamic nicotinic receptors. The authors test this by separately attempting to block or enhance anesthetic-induced loss of righting in rats using intrathalamic microinjections of nicotine or its antagonist.

Methods

Rats were implanted with a cannula aimed at the thalamus or control locations. A week later, loss of righting was induced using sevoflurane (1.4 +/- 0.2%). A dose-parameter study (n = 35) first identified an optimal intrathalamic nicotine dose associated with arousal. Subsequently, this dose was used to pinpoint the thalamic site mediating the arousal response (n = 107). Finally, sevoflurane righting dose and response specificity were assessed after blocking nicotinic channels with intrathalamic mecamylamine pretreatment (n = 8) before nicotine challenge.

Results

Nicotine (150 microg/0.5 microl over 1 min) was the optimal arousal dose, because lower doses (75 microg) were ineffective and higher doses (300 microg) often caused seizures. Nicotine temporarily restored righting and mobility in animals when microinjections involved the central medial thalamus (P < 0.0001, chi-square). Righting occurred despite continued sevoflurane administration. Intrathalamic mecamylamine pretreatment did not lower the sevoflurane dose associated with loss of righting, but prevented the nicotine arousal response.

Conclusions

The reversal of unconsciousness found here with intrathalamic microinfusion of nicotine suggests that suppression of the midline thalamic cholinergic arousal system is part of the mechanism by which anesthetics produce unconsciousness.
Resuscitation with Recombinant Hemoglobin rHb2.0 in a Rodent Model of Hemorrhagic Shock
Authors: Hermann Joerg , Corso Carlos , Messmer Konrad F.
Published: July 2007

Background

Hemoglobin solutions combine volume effect, oxygen-carrying capacity, and vasoactive properties, the latter facilitating restoration of global hemodynamics but endangering microvascular resuscitation. Hemoglobin-evoked vasoconstriction probably is due to nitric oxide scavenging, which can be reduced by genetic modifications of the heme pocket. This study compares resuscitation with a nonhemoglobin colloid and two recombinant hemoglobin solutions with wild-type and reduced nitric oxide-scavenging capacity.

Methods

Twenty-seven awake Syrian golden hamsters fitted with dorsal skinfold chambers underwent a 30 min-hemorrhagic shock (mean arterial pressure [MAP] 30-35 mmHg) and resuscitation with shed blood volume of either 6% dextran 60 (Biophausia, Uppsala, Sweden), recombinant hemoglobin 1.1 (rHb1.1; wild-type nitric oxide-scavenging capacity; 10 g/dl), or recombinant hemoglobin 2.0 (rHb2.0; reduced nitric oxide-scavenging capacity; 10 g/dl; both Baxter Healthcare, Boulder, CO). Macrohemodynamic and laboratory parameters were assessed; microvascular parameters in the skinfold chamber were analyzed by intravital microscopy.

Results

Hemorrhagic shock reduced functional capillary density (FCD) by 70% and caused significant metabolic acidosis. Colloid resuscitation led to incomplete recovery of MAP and FCD. Infusion of rHb1.1 completely restored MAP but not FCD, with the smallest arteriolar diameters found in this group. FCD was restored best by resuscitation with rHb2.0, although MAP was lower than in rHb1.1-treated animals. Metabolic acidosis was resolved by both hemoglobin solutions, but not by dextran.

Conclusion

After resuscitation with rHb1.1, arteriolar vasoconstriction quickly restored MAP, but this was achieved at the expense of FCD. In contrast, after resuscitation with rHb2.0, the recovery of MAP could be translated into a significantly improved FCD.
The Quaternary Lidocaine Derivative, QX-314, Produces Long-lasting Local Anesthesia in Animal Models In Vivo
Authors: Lim Tony K. Y. , MacLeod Bernard A. , Ries Craig R. , Schwarz Stephan K. W.
Published: July 2007

Background

QX-314 is a quaternary lidocaine derivative considered to be devoid of clinically useful local anesthetic activity. However, several reports document that extracellular QX-314 application affects action potentials. Hence, the authors tested the hypothesis that QX-314 could produce local anesthesia in animal models in vivo.

Methods

The authors tested QX-314 (10, 30, and 70 mM) in three standard in vivo local anesthetic animal models, using a randomized, blinded experimental design with negative (placebo) and positive (70 mM lidocaine) controls. The guinea pig intradermal wheal assay (n = 29) was used to test for peripheral inhibition of the cutaneous trunci muscle reflex, the mouse tail-flick test (n = 30) was used to test for sensory blockade, and the mouse sciatic nerve blockade model (n = 45) was used to test for motor blockade.

Results

In all three animal models, QX-314 concentration-dependently and reversibly produced local anesthesia of long duration, at concentrations equivalent to those clinically relevant for lidocaine. In the guinea pig intradermal wheal assay, QX-314 produced peripheral nociceptive blockade up to 6 times longer than lidocaine (650 +/- 171 vs. 100 +/- 24 min [mean +/- SD]; n = 6 per group; P < 0.0001). In the mouse tail-flick test, QX-314 produced sensory blockade up to 10 times longer than lidocaine (540 +/- 134 vs. 50 +/- 11 min; n = 6 per group; P < 0.0001). Finally, in the mouse sciatic nerve model, QX-314 produced motor blockade up to 12 times longer compared with lidocaine (282 +/- 113 vs. 23 +/- 10 min; n = 9 or 10 per group; P < 0.0001). The onset of QX-314-mediated blockade was consistently slower compared with lidocaine. Animals injected with saline exhibited no local anesthetic effects in any of the three models.

Conclusion

In a randomized, controlled laboratory study, the quaternary lidocaine derivative, QX-314, concentration-dependently and reversibly produced long-lasting local anesthesia with a slow onset in animal models in vivo. The authors' results raise the possibility that quaternary ammonium compounds may produce clinically useful local anesthesia of long duration in humans and challenge the conventional notion that these agents are ineffective when applied extracellularly.
Local Inflammation in Rat Dorsal Root Ganglion Alters Excitability and Ion Currents in Small-diameter Sensory Neurons
Authors: Wang Jun-Gang , Strong Judith A. , Xie Wenrui , Zhang Jun-Ming
Published: July 2007

Background

Chronic pain conditions may result from peripheral nerve injury, chronic peripheral inflammation, or sensory ganglia inflammation. However, inflammatory processes may also contribute to peripheral nerve injury responses. To isolate the contribution of local inflammation of sensory ganglia to chronic pain states, the authors previously developed a rat model in which long-lasting pain is induced by inflaming sensory ganglia without injuring the neurons. This results in prolonged mechanical pain, local increases in proinflammatory cytokines, increased neuronal hyperexcitability, and abnormal spontaneous activity.

Methods

The authors used whole cell patch clamp in acutely isolated small-diameter neurons to determine how localized inflammation (3-5 days) of L4 and L5 ganglia altered voltage-gated K and Na currents.

Results

Tetrodotoxin-sensitive Na currents increased twofold to threefold in neurons from inflamed ganglia. Tetrodotoxin-resistant Na currents increased more than twofold, but only in cells that bound isolectin B4. These increases occurred without shifts in voltage dependence of activation and inactivation. Similar results are seen in models of peripheral inflammation, except for the large magnitudes. Unlike most pain models, localized inflammation increased rather than decreased voltage-gated K currents, due to increased amplitudes of the sustained (delayed rectifier) and fast-inactivating transient components. The overall effect in current clamp experiments was an increase in excitability as indicated by decreased rheobase and lower action potential threshold.

Conclusions

Neuronal inflammation per se, in the absence of nerve injury, causes large increases in Na channel density and enhanced excitability. The unusual finding of increased K current may reflect regulation of excitability in the face of such large increases in Na current.
The Novel Hemoglobin-based Oxygen Carrier HRC 101 Improves Survival in Murine Sickle Cell Disease
Authors: Crawford Mark W. , Shichor Tal , Engelhardt Thomas , Adamson Gord , Bell David , Carmichael F J. Lou , Kim Peter C. W.
Published: July 2007

Background

Erythrocyte transfusion decreases morbidity in sickle cell disease, but is not without risk. Use of a hemoglobin-based oxygen carrier could offer the benefits of erythrocyte transfusion while reducing related complications. The authors tested the hypothesis that the novel hemoglobin-based oxygen carrier, HRC 101, would improve survival during exposure to acute hypoxia in a murine model of sickle cell disease, the transgenic mouse expressing hemoglobin SAD (alpha2beta2).

Methods

Wild-type (n = 30) and transgenic SAD (n = 36) mice received 0.02 ml/g HRC 101 (hemoglobin concentration, 10 g/dl) or an equal volume of 5% albumin. Thirty percent or 6% oxygen was administered to spontaneously breathing mice during halothane anesthesia (inspired concentration, 0.5%). The time to cessation of cardiac electrical activity was recorded. Survival was compared using Kaplan-Meier analysis.

Results

Control mice survived the 60-min study period, whether breathing 30% or 6% oxygen. In contrast, all SAD mice given albumin and 6% oxygen died, with a median survival time of 9.0 min (interquartile range, 6.9-11.6 min; P < 0.0001). HRC 101 significantly increased survival in SAD mice breathing 6% oxygen. Of 12 SAD mice given HRC 101 and 6% oxygen, 4 survived the entire study period and 8 died, with a median survival time of 48 min (19-60 min; P < 0.0001 vs. albumin).

Conclusion

HRC 101 significantly decreased sickle-related mortality during exposure to acute hypoxic stress in transgenic mice expressing hemoglobin SAD. HRC 101 warrants further evaluation as a therapeutic modality in sickle cell disease.
Oxidative stress, and iron and antioxidant status in elderly men: differences between the Mediterranean south (Crete) and northern Europe (Zutphen)
Authors: Buijsse Brian , Feskens Edith J. , Moschandreas Joanna , Jansen Eugène H. , Jacobs David R. , Kafatos Anthony , Kok Frans J. , Kromhout Daan
Published: July 2007

Background

Oxidative stress may accelerate ageing and increase the risk of chronic diseases, such as coronary heart disease (CHD). We assessed differences in oxidative stress, and iron and antioxidant status between elderly men living in Mediterranean southern Europe (Crete, Greece) and northern Europe (Zutphen, The Netherlands).

Design

A cross-sectional study using data from two cohorts of the Seven Countries Study.

Methods

Non-fasting blood samples were drawn in 2000 from 105 men from Crete and 139 men from Zutphen, all aged 79 years or over. All assays were performed in the same laboratory.

Results

After multiple adjustments, serum levels of the markers of oxidative stress were lower in Cretan men than in men from Zutphen, as indicated by lower mean levels of hydroperoxides (33.2 versus 57.3 μmol/l; P = 0.005) and gamma-glutamyltransferase (20.3 versus 26.1 U/I; P = 0.003). The most pronounced difference in iron status was a twofold lower mean serum ferritin level in Cretan men (69.8 μg/I) compared with men from Zutphen (134.2 μg/I; P < 0.0001). Men from Crete had consistently higher plasma levels of major plasma antioxidants than the Zutphen men, including a nearly fourfold higher mean level of lycopene (15.3 versus 4.1 μg/100 ml; P < 0.0001).

Conclusion

Elderly men from Crete had consistently lower levels of the indicators of oxidative stress and iron status and higher concentrations of major antioxidants than men from Zutphen. These differences may contribute to the lower rate of CHD and total mortality that has been observed in this cohort of Cretan men.
Low cardiorespiratory fitness is a strong predictor for clustering of cardiovascular disease risk factors in children independent of country, age and sex
Authors: Anderssen Sigmund A. , Cooper Ashley R. , Riddoch Chris , Sardinha Luis B. , Harro Maarike , Brage Søren , Andersen Lars B.
Published: July 2007

Background and design

Few studies have investigated the association between maximal cardiorespiratory capacity (fitness) and the clustered cardiovascular disease (CVD) risk in children and youth from culturally diverse countries. This cross-sectional study examined the association between fitness and clustered CVD risk in children and adolescents from three European countries.

Methods

Participants were 2845 randomly selected school children aged 9 or 15 years from Portugal ( n = 944), Denmark ( n = 849) and Estonia ( n = 1052). Cardiorespiratory fitness was determined during a maximal test on a cycle ergometer. CVD risk factors selected to assess the degree of clustering were the total cholesterol/high-density lipoprotein cholesterol ratio, plasma triglycerides, insulin resistance (homeostasis model assessment), sum of four skinfolds, and systolic blood pressure.

Results

There was a strong association between cardiorespiratory fitness and the clustering of CVD risk factors. The odds ratios for clustering in each quartile of fitness, using the quartile with the highest fitness as reference, were 13.0 [95% confidence interval (CI) 8.8-19.1]; 4.8 (95% CI 3.2-7.1) and 2.5 (95% CI 1.6-3.8), respectively, after adjusting for country, age, sex, socio-economic status, pubertal stage, family history of CVD and diabetes. In stratified analyses by age group, sex and country, similar strong patterns were observed.

Conclusion

Low cardiorespiratory fitness is strongly associated with the clustering of CVD risk factors in children independent of country, age and sex.
Primary risk factors influence risk of recurrent myocardial infarction/death from coronary heart disease: results from the Stockholm Heart Epidemiology Program (SHEEP)
Authors: Leander Karin , Wiman Björn , Hallqvist Johan , Andersson Tomas , Ahlbom Anders , de Faire Ulf
Published: July 2007

Background

Prognosis after a first myocardial infarction (MI) is influenced by primary risk factors as well as secondary risk factors. There is still a lack of follow-up studies of well-characterized patient cohorts assessing the relative importance of these factors.

Design

A cohort of 1635 patients (aged 45-70 years) surviving at least 28 days after a first MI were followed for 6-9 years with regard to recurrent MI/fatal coronary heart disease (CHD). Data were collected through questionnaires, physical examinations, and medical records.

Methods

Hazard ratios (HR) with 95% confidence intervals (CI) for different risk factors were calculated using the Cox proportional hazard model.

Results

Of the primary risk factors, diabetes in both sexes was the most important predictor of recurrent MI/fatal CHD, multivariate-adjusted HR in men 1.6 (95% CI; 1.0-2.4) and in women 2.5 (95% CI; 0.9-6.9). Other primary risk factors with prognostic influence were job strain, HR 1.5 (95% CI; 1.0-2.1), and central obesity, HR 1.4 (95% CI; 1.0-2.0), in men and a low level of apolipoprotein A1, HR 2.3 (95% CI; 1.1-5.0), and high-density lipoprotein cholesterol, HR 1.9 (95% CI; 0.9-4.1), in women. The secondary risk factors most detrimental for prognosis were heart failure in men, HR 2.2 (95% CI; 1.2-4.0), and a high peak acute cardiac enzyme level in women, HR 4.4 (95% CI; 2.0-9.7).

Conclusions

Long-term follow-up of patients who survived at least 28 days after a first MI shows that several primary cardiovascular risk factors, particularly diabetes, contribute to the increased risk of recurrent MI/fatal CHD.
Secondary prevention programmes for coronary heart disease: a meta-regression showing the merits of shorter, generalist, primary care-based interventions
Authors: Clark Alexander M. , Hartling Lisa , Vandermeer Ben , Lissel Sue L. , McAlister Finlay A.
Published: July 2007

Background

The aim of this study was to determine which programme characteristics influence the effectiveness of secondary prevention programmes for Coronary Heart Disease.

Design

The study follows a meta-regression design.

Methods

We conducted a meta-regression within a systematic review of randomized trials comparing secondary prevention programmes versus usual care. The primary outcome was all-cause mortality. Studies were identified by searching multiple electronic databases, bibliographies of published studies, contact with experts, and references provided by the United States Centers for Medicare and Medicaid Services. Primary authors of all relevant trials were surveyed for detailed information on programme characteristics. Forty-six unique trials were identified (18 821 patients). The pooled all-cause mortality risk ratio (RR) for programmes was 0.87 [95% confidence interval (CI) 0.79-0.97]. Programmes containing less than 10 h of patient contact with health professionals reduced all-cause mortality (RR 0.80, 95% CI 0.68-0.95) as effectively as programmes with more contact time. Programmes provided in general practice settings were effective at reducing all-cause mortality (RR 0.76, 95% CI 0.63-0.92) and compared favourably with the effectiveness of hospital-based programmes. Other characteristics, including specialist versus generalist provision, did not appreciably impact programme effectiveness.

Conclusions

Shorter secondary prevention programmes, those based in general practice, and those staffed by generalists are at least as effective in reducing all cause mortality in patients with coronary heart disease as longer programmes, hospital-based programmes, and programmes staffed by specialists.
Symptoms of anxiety and depression in patients with stable coronary heart disease: prognostic value and consideration of pathogenetic links
Authors: Rothenbacher Dietrich , Hahmann Harry , Wüsten Bernd , Koenig Wolfgang , Brenner Hermann
Published: July 2007

Background

We evaluated the association of symptoms of anxiety and depression with fatal and non-fatal cardiovascular disease events among patients with coronary heart disease and considered several potential underlying pathogenetic links.

Design

This was a prospective cohort study.

Methods

In this study, including coronary heart disease patients undergoing an in-patient rehabilitation program, symptoms of anxiety and depression were evaluated with the Hospital Anxiety and Depression Scale (HADS). Fatal and non-fatal cardiovascular disease events were determined during a 3-year follow-up.

Results

Of the 1052 patients with CHD 16.1% showed a borderline and 8.3% a manifest anxiety symptoms score, whereas 11.8 and 5.9% showed a borderline and manifest depressive symptoms score, respectively. During the 3-year follow-up fatal and non-fatal cardiovascular disease events were observed in 73 (6.9%) patients. After adjustment for covariates, patients having manifest anxiety symptoms had a statistically significant hazard ratio (HR) of 2.32 [95% confidence interval (CI) 1.14-4.74] for a cardiovascular disease event, and patients with depressive symptoms had an HR of 1.47 (95% CI 0.62-3.51) compared to other patients. In a model considering anxiety and depressive symptom scores simultaneously, the hazard ratio for a cardiovascular disease event associated with anxiety symptoms increased to 3.31 (95% CI 1.32-8.27), whereas the hazard ratio associated with depressive symptoms decreased (HR 0.62; 95% CI 0.20-1.87). We found a positive association of increased anxiety scores with body mass index and systolic blood pressure.

Conclusions

The study suggests an important role especially for symptoms of anxiety for long-term prognosis of patients with known coronary heart disease. It furthermore suggests that several pathogenetic links may partly explain the increased risk.
Association between intelligence and coronary heart disease mortality: a population-based cohort study of 682 361 Swedish men
Authors: Silventoinen Karri , Modig-Wennerstad Karin , Tynelius Per , Rasmussen Finn
Published: July 2007

Background

Socio-economic position and intelligence predict coronary heart disease but their mutual associations are not yet well understood. We investigated associations between intelligence and coronary heart disease mortality and explored if they are confounded or modified by socio-economic position.

Design

This was a cohort-based follow-up study.

Methods

Data on intelligence, systolic and diastolic blood pressures and body mass index were measured at conscription examination at age 18 years in 682 361 Swedish men born 1951-1965. Data on parental and own education and social position were derived from censuses in 1960, 1970, 1980 and 1990. Follow-up data up to end of 2001 were derived from the Swedish Cause of Death Register and 737 coronary heart disease deaths were observed. Data were analyzed by Cox regression and conditional logistic regression models.

Results

An inverse association was found between intelligence and coronary heart disease mortality after adjustment for parental and own education and social position, body mass index and blood pressure (hazard ratio 0.92; 95% confidence interval 0.88-0.96). These associations were of similar strengths within all socio-economic categories and also found within 215 brother pairs discordant for coronary heart disease mortality and intelligence (odds ratio 0.76; 95% confidence interval 0.58-1.00).

Conclusions

Intelligence is associated with coronary heart disease mortality independently of socio-economic position. Health education messages should be tailored according to intellectual performance of the recipients, but also other factors are important for socio-economic coronary heart disease inequalities.
Subclinical coronary atherosclerosis is more pronounced in men and women with lower socio-economic status: associations in a population-based study Coronary atherosclerosis and social status
Authors: Dragano Nico , Verde Pablo Emilio , Moebus Susanne , Stang Andreas , Schmermund Axel , Roggenbuck Ulla , Möhlenkamp Stefan , Peter Richard , Jöckel Karl-Heinz , Erbel Raimund , Siegrist Johannes ,   for the Heinz Nixdorf Recall Study
Published: July 2007

Background

Social inequalities of manifest coronary heart diseases are well documented in modern societies. Less evidence is available on subclinical atherosclerotic disease despite the opportunity to investigate processes underlying this association. Therefore, we examined the relationship between coronary artery calcification as a sign of subclinical coronary atherosclerosis, socio-economic status and established cardiovascular risk factors in a healthy population.

Design

Cross-sectional.

Methods

In a population-based sample of 4487 men and women coronary artery calcification was assessed by electron beam computed tomography quantified by the Agatston score. Socio-economic status was assessed by two indicators, education and income. First, we investigated associations between the social measures and calcification. Second, we assessed the influence of cardiovascular risk factors on this association.

Results

After adjustment for age, men with 10 and less years of formal education had a 70% increase in calcification score compared with men with high education. The respective increase for women was 80%. For income the association was weaker (among men 20% higher for the lowest compared with the highest quartile; and among women 50% higher, respectively). Consecutive adjustment for cardiovascular risk factors significantly attenuated the observed association of socio-economic status with calcification.

Conclusions

Social inequalities in coronary heart diseases seem to influence signs of subclinical coronary atherosclerosis as measured by coronary artery calcification. Importantly, cumulation of major cardiovascular risk factors in lower socio-economic groups accounted for a substantial part of this association.
Illicit drugs and cardiac arrhythmias in athletes
Authors: Furlanello Francesco , Serdoz Laura Vitali , Cappato Riccardo , De Ambroggi Luigi
Published: July 2007

The current management of athletes with cardiac arrhythmias has become complicated by the widespread use of illicit drugs, which can be arrhythmogenic.

The World Anti-Doping Agency annually updates a list of prohibited substances and methods banned by the International Olympic Committee that includes different classes of substances namely, anabolic androgenic steroids, hormones and related substances, β2-agonists, diuretics, stimulants, narcotics, cannabinoids, glucocorticosteroids, alcohol, β-blockers and others. Almost all illicit drugs may cause, through a direct or indirect arrhythmogenic effect, a wide range of cardiac arrhythmias (focal or reentry type, supraventricular and/or ventricular) that can even be lethal and which are frequently sport activity related.

A large use of illicit drugs has been documented in competitive athletes, but the arrhythmogenic effect of specific substances is not precisely known. Precipitation of cardiac arrhythmias, particularly in the presence of a latent electrophysiologic substrate including some inherited cardiomyopathies, at risk of sudden death or due to long-term consumption of the substances, should raise the suspicion that illicit drugs may be a possible cause and lead cardiologists to investigate carefully this relationship and appropriately prevent the clinical consequences.
Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition
Authors: Erickson Gregory M , Curry Rogers Kristina , Varricchio David J , Norell Mark A , Xu Xing
Published: July 2007

The timing of sexual maturation in non-avian dinosaurs is not known. In extant squamates and crocodilians it occurs in conjunction with the initial slowing of growth rates as adult size is approached. In birds (living dinosaurs) on the other hand, reproductive activity begins well after somatic maturity. Here we used growth line counts and spacing in all of the known brooding non-avian dinosaurs to determine the stages of development when they perished. It was revealed that sexual maturation occurred well before full adult size was reached—the primitive reptilian condition. In this sense, the life history and physiology of non-avian dinosaurs was not like that of modern birds. Palaeobiological ramifications of these findings include the potential to deduce reproductive lifespan, fecundity and reproductive population sizes in non-avian dinosaurs, as well as aid in the identification of secondary sexual characteristics.
Smaller beetles are better scramble competitors at cooler temperatures
Authors: Moya-Laraño Jordi , El-Sayyid Maysaa El Tigani , Fox Charles W
Published: July 2007

The role of temperature is central to both organic evolution and ecological processes. However, how temperature affects selection on body size is unknown. We tested whether small seed beetles (
Stator limbatus
) have an advantage over large beetles during scramble competition for mates, and whether this advantage varies with temperature. Within lines of beetles artificially selected to be large versus small, small males have a significant advantage over large males in scramble competition for females because the former takeoff more quickly and thus reach females before larger males. Selection favouring small male body size is significantly (and substantially) more intense at cooler temperatures. The adaptive significance of small male body size thus depends on ambient temperature.
On methods for studying stochastic disease dynamics
Authors: Keeling M.J , Ross J.V
Published: July 2007

Models that deal with the individual level of populations have shown the importance of stochasticity in ecology, epidemiology and evolution. An increasingly common approach to studying these models is through stochastic (event-driven) simulation. One striking disadvantage of this approach is the need for a large number of replicates to determine the range of expected behaviour. Here, for a class of stochastic models called Markov processes, we present results that overcome this difficulty and provide valuable insights, but which have been largely ignored by applied researchers. For these models, the so-called Kolmogorov forward equation (also called the ensemble or master equation) allows one to simultaneously consider the probability of each possible state occurring. Irrespective of the complexities and nonlinearities of population dynamics, this equation is linear and has a natural matrix formulation that provides many analytical insights into the behaviour of stochastic populations and allows rapid evaluation of process dynamics. Here, using epidemiological models as a template, these ensemble equations are explored and results are compared with traditional stochastic simulations. In addition, we describe further advantages of the matrix formulation of dynamics, providing simple exact methods for evaluating expected eradication (extinction) times of diseases, for comparing expected total costs of possible control programmes and for estimation of disease parameters.
NMR measurements and hydrodynamic simulations of phase-resolved velocity distributions within a three-dimensional vibrofluidized granular bed
Authors: Huntley J.M , Martin T.W , Mantle M.D , Shattuck M.D , Sederman A.J , Wildman R.D , Gladden L.F , Halliwell N.A
Published: July 2007

We report the results of nuclear magnetic resonance imaging experiments on vertically vibrated granular beds of mustard grains. A novel spin-echo velocity profiling technique was developed that allows granular temperature, mean velocity and packing fraction distributions within the three-dimensional cell to be measured as a function of both vertical position and vibration phase. Bimodal velocity distributions were observed at certain portions of the vibration cycle, and in general the ability to acquire time-resolved data demonstrated the significant distortions to the velocity distributions and the systematic errors in calculated temperature distributions that may arise with time-averaged measurements. The experimental behaviour was compared with predictions from a time-varying one-dimensional hydrodynamic model using the experimental parameters as input to the code. In both cases, damping of longitudinal sound waves was linked to significant volume heating effects, which contrasts with the usual heat transport mechanism (i.e. diffusion from the boundaries) currently assumed in most steady-state models. This leads to a new explanation for the counterintuitive upturn in granular temperature in vibrofluidized granular beds, based on amplification and damping of sound waves in the high-altitude region.
Point process models of rainfall: developments for fine-scale structure
Authors: Cowpertwait Paul , Isham Valerie , Onof Christian
Published: July 2007

A conceptual stochastic model of rainfall is proposed in which storm origins occur in a Poisson process, where each storm has a random lifetime during which rain cell origins occur in a secondary Poisson process. In addition, each cell has a random lifetime during which instantaneous random depths (or ‘pulses’) of rain occur in a further Poisson process. A key motivation behind the model formulation is to account for the variability in rainfall data over small (e.g. 5 min) and larger time intervals. Time-series properties are derived to enable the model to be fitted to aggregated rain gauge data. These properties include moments up to third order, the probability that an interval is dry, and the autocovariance function. To allow for distinct storm types (e.g. convective and stratiform), several processes may be superposed. Using the derived properties, a model consisting of two storm types is fitted to 60 years of 5 min rainfall data taken from a site near Wellington, New Zealand, using sample estimates taken at 5 min, 1 hour, 6 hours and daily levels of aggregation. The model is found to fit moments of the depth distribution up to third order very well at these time scales. Using the fitted model, 5 min series are simulated, and annual maxima are extracted and compared with equivalent values taken from the historical record. A good fit in the extremes is found at both 1 and 24 hour levels of aggregation, although at the 5 min level there is some underestimation of the historical values. Proportions of time intervals with depths below various low thresholds are extracted from the simulated and historical series and compared. A tendency for underestimation of the historical values is evident at some time scales, with a close fit being obtained as the threshold is increased.
Democracy in animals: the evolution of shared group decisions
Authors: Conradt L , Roper T.J
Published: July 2007

A ‘consensus decision’ is when the members of a group choose, collectively, between mutually exclusive actions. In humans, consensus decisions are often made democratically or in an ‘equally shared’ manner, i.e. all group members contribute to the decision. Biologists are only now realizing that shared consensus decisions also occur in social animals (other than eusocial insects). Sharing of decisions is, in principle, more profitable for groups than accepting the ‘unshared’ decision of a single dominant member. However, this is not true for all individual group members, posing a question as to how shared decision making could evolve. Here, we use a game theory model to show that sharing of decisions can evolve under a wide range of circumstances but especially in the following ones: when groups are heterogeneous in composition; when alternative decision outcomes differ in potential costs and these costs are large; when grouping benefits are marginal; or when groups are close to, or above, optimal size. Since these conditions are common in nature, it is easy to see how mechanisms for shared decision making could have arisen in a wide range of species, including early human ancestors.