Suitability of machine learning models for prediction of clinically defined Stage III/IV periodontitis from questionnaires and demographic data in Danish cohorts

AIM

To evaluate if, and to what extent, machine learning models can capture clinically defined Stage III/IV periodontitis from self-report questionnaires and demographic data.

MATERIALS AND METHODS

Self-reported measures of periodontitis, demographic data and clinically established Stage III/IV periodontitis status were extracted from two Danish population-based cohorts (The Copenhagen Aging and Midlife Biobank [CAMB] and The Danish Health Examination Survey [DANHES]) and used to develop cross-validated machine learning models for the prediction of clinically established Stage III/IV periodontitis. Models were trained using 10-fold cross-validations repeated three times on the CAMB dataset (n = 1476), and the resulting models were validated in the DANHES dataset (n = 3585).

RESULTS

The prevalence of Stage III/IV periodontitis was 23.2% (n = 342) in the CAMB dataset and 9.3% (n = 335) in the DANHES dataset. For the prediction of clinically established Stage III/IV periodontitis in the CAMB cohort, models reached area under the receiver operating characteristics (AUROCs) of 0.67-0.69, sensitivities of 0.58-0.64 and specificities of 0.71-0.80. In the DANHES cohort, models derived from the CAMB cohort achieved AUROCs of 0.64-0.70, sensitivities of 0.44-0.63 and specificities of 0.75-0.84.

CONCLUSIONS

Applying cross-validated machine learning algorithms to demographic data and self-reported measures of periodontitis resulted in models with modest capabilities for the prediction of Stage III/IV periodontitis in two Danish cohorts.

381. The Importance of Data Accuracy and Transparency for Policymaking During a Public Health Crisis: A Case Study in the State of Iowa

Background

High-quality data are necessary for decision-making during the SARS-CoV-2 pandemic. Lack of transparency and accuracy in data reporting can erode public confidence, mislead policymakers, and endanger safety. Two major data errors in Iowa impacted critical state- and county-level decision-making.

Methods

The Iowa Department of Public Health (IDPH) publishes daily COVID-19 data. Authors independently tracked daily data from IDPH and other publicly available sources (i.e., county health departments, news media, and social networks). Data include: number and type of tests, results, hospitalizations, intensive care unit admissions, and deaths at state/county levels.

Results

Discrepancies were identified between IDPH and non-IDPH data, with at least two confirmed by IDPH: (1) The backdating of test results identified on May 28, 2020. IDPH labeled results as occurring up to four months before the actual test date. IDPH confirmed that if a person previously tested for SARS-CoV-2, a new test result was attributed to the initial test’s date. Corrections on August 19, 2020 increased positivity rates in 31 counties, but decreased the state’s overall rate (9.1% to 7.5%). (2) The selective exclusion of antigen test results noted on August 20, 2020. Antigen testing was included in the total number of tests reported in metric denominators, but their results were being excluded from their respective numerators. Thus, positive antigen results were interpreted as de facto negative tests, artificially lowering positivity rates. Corrections increased Iowa’s positivity rate (5.0% to 14.2%). In July 2020, the Iowa Department of Education mandated in-person K-12 learning for counties with < 15% positivity. These data changes occurred during critical decision-making, altering return-to-learn plans in seven counties. The Center for Medicare and Medicaid Services’ requirements also caused nursing homes to urgently revise testing strategies.

Timeline of changes to Iowa state COVID-19 testing through the end of August 2020.

Change in positive and overall test results due to IDPH data corrections. These graphs represent the difference in cumulative total reported test results when pulled from the IDPH website on September 29, 2020 compared to data for the same dates when pulled on August 19, 2020 before the announced adjustment. The adjustment and subsequent daily changes in reported data amount to a dramatic change in the number of reported positive cases (A) with an increase of nearly 3,000 cases by April 25, as well as the loss of tens of thousands of data points when tracking total resulted tests (B).

Conclusion

Data availability, quality, and transparency vary widely across the US, hindering science-based policymaking. Independent audit and curations of data can contribute to better public health policies. We urge all states to increase the availability and transparency of public health data.

Disclosures

All Authors: No reported disclosures

Risk of self-harm and nonfatal suicide attempts, and completed suicide in patients with psoriasis: a population-based cohort study

BACKGROUND

Psoriasis is a common inflammatory skin disease, and inflammation may affect suicidal behaviour. Current data on the incidence and risk of suicidal behaviour in patients with psoriasis are scarce.

OBJECTIVES

We investigated the association between psoriasis and the risk of self-harm and suicide attempts and suicides.

METHODS

All Danish patients aged ≥ 18 years with mild or severe psoriasis (cases) from 1 January 1997 to 31 December 2011 were matched on age, sex and calendar time 1 : 5 with healthy controls. The outcome was a diagnosis of self-harm or a nonfatal suicide attempt, or completed suicide. Incidence rates per 10 000 person-years were calculated, and incidence rate ratios (IRRs) and confidence intervals (CIs) were estimated by Poisson regression models.

RESULTS

The study cohort comprised 408 663 individuals, including 57 502 and 11 009 patients with mild and severe psoriasis, respectively. In total 280 cases of self-harm or suicide attempts, and 574 suicides occurred during follow-up. There was no increased risk of self-harm or suicide attempts in patients with mild psoriasis (IRR 1·01, 95% CI 0·17-2·01), but this risk was significantly increased in severe psoriasis (IRR 1·69, 95% CI 1·00-2·84). There was no increased risk of suicides in mild (IRR 1·05, 95% CI 0·84-1·32) or severe psoriasis (IRR 0·78, 95% CI 0·45-1·36). Similar results were found when suicides were confirmed by official forensic investigations, and when psoriasis was compared with atopic dermatitis.

CONCLUSIONS

We found limited evidence to suggest an increased risk of self-harm and nonfatal suicide attempts in patients with psoriasis. Importantly, after adjustment for psoriatic arthritis this risk was no longer significantly increased. The risk of completed suicide was also not increased, regardless of psoriasis severity.

Risk of periodontitis in patients with psoriasis and psoriatic arthritis

BACKGROUND

Psoriasis and periodontitis are chronic inflammatory disorders with overlapping inflammatory pathways, but data on risk of periodontitis in psoriasis are scarce and a possible pathogenic link is poorly understood.

OBJECTIVE

We investigated the association between psoriasis and periodontitis in a nationwide cohort study.

METHODS

All Danish individuals aged ≥18 years between 1 January 1997 and 31 December 2011 (n = 5,470,428), including 54 210 and 6988 patients with mild and severe psoriasis, and 6428 with psoriatic arthritis, were linked through administrative registers. Incidence rate ratios (IRRs) were estimated by Poisson regression.

RESULTS

Incidence rates of periodontitis per 10 000 person-years were 3.07 (3.03-3.12), 5.89 (1.07-6.84), 8.27 (5.50-12.45) and 11.12 (7.87-15.73) for the reference population, mild psoriasis, severe psoriasis and psoriatic arthritis respectively. Adjusted IRRs were (1.66; 1.43-1.94) for mild psoriasis, (2.24; 1.46-3.44) for severe psoriasis and (3.48; 2.46-4.92) for psoriatic arthritis. Similar results were found when a case-control design was applied.

CONCLUSIONS

We found a significant psoriasis-associated increased risk of periodontitis, which was highest in patients with severe psoriasis and psoriatic arthritis.

Association between psoriasis and inflammatory bowel disease: a Danish nationwide cohort study

BACKGROUND

Psoriasis, Crohn disease (CD) and ulcerative colitis (UC) are chronic inflammatory disorders with overlapping genetic architecture. However, data on the frequency and risk of CD and UC in psoriasis are scarce and poorly understood.

OBJECTIVES

To investigate the association between CD and UC in patients with psoriasis.

METHODS

All Danish individuals aged ≥ 18 years between 1 January 1997 and 31 December 2012 were linked in nationwide registers. Psoriasis severity was defined in two models: hospital visits and medication. Incidence rates per 10 000 person-years were calculated, and incidence rate ratios (IRRs) were estimated by Poisson regression.

RESULTS

In the total cohort (n = 5 554 100) there were 75 209 incident cases of psoriasis, 11 309 incident cases of CD and 30 310 incident cases of UC, during follow-up. The adjusted IRRs (95% confidence intervals) of CD were 1·28 (1·03-1·59), 2·56 (1·87-3·50), 2·85 (1·72-4·73) and 3·42 (2·36-4·95) in patients with mild psoriasis, severe psoriasis (hospital), severe psoriasis (medication) and psoriatic arthritis, respectively. Similarly, the adjusted IRRs of UC were 1·49 (1·32-1·68), 1·56 (1·22-2·00), 1·96 (1·36-2·83) and 2·43 (1·86-3·17), respectively. The 10-year incidence of CD was 2-5 per 1000 patients and of UC 7-11 per 1000 patients, depending on psoriasis severity and the presence of psoriatic arthritis. Additionally, an increased risk of incident psoriasis was found following CD or UC.

CONCLUSIONS

We observed a psoriasis-associated increased risk of CD and UC, which was higher in severe psoriasis, and an increased risk of psoriasis in patients with inflammatory bowel disease. Increased focus on gastrointestinal symptoms in patients with psoriasis may be warranted.

Risk of psoriasis in patients with childhood asthma: a Danish nationwide cohort study

BACKGROUND

Psoriasis and asthma are disorders driven by inflammation. Psoriasis may carry an increased risk of asthma, but the reverse relationship has not been investigated.

OBJECTIVES

To investigate the risk of psoriasis in subjects with childhood asthma in a nationwide Danish cohort.

METHODS

Data on all Danish individuals aged 6-14 years at study entry between 1 January 1997 and 31 December 2011 (n = 1,478,110) were linked at an individual level in nationwide registers. Incidence rates per 10,000 person-years were calculated, and incidence rate ratios (IRRs) adjusted for age, sex, concomitant medication and comorbidity were estimated by Poisson regression models.

RESULTS

There were 21,725 cases of childhood asthma and 6586 incident cases of psoriasis. There were 5697 and 889 incident cases of mild and severe psoriasis, respectively. The incidence rates of overall, mild and severe psoriasis were 4.49, 3.88 and 0.61 for the reference population, and 5.95, 5.18 and 0.83 for subjects with childhood asthma, respectively. The IRRs for overall, mild and severe psoriasis were 3.94 [95% confidence interval (CI) 2.16-7.17], 5.03 (95% CI 2.48-10.21) and 2.27 (95% CI 0.61-8.42) for patients with childhood asthma.

CONCLUSIONS

Childhood asthma was associated with a significantly increased risk of psoriasis. Further studies are warranted to determine the clinical significance and effects of therapeutic interventions on this association.

Myocardial function and effects of biologic therapy in patients with severe psoriasis: a prospective echocardiographic study

BACKGROUND

Psoriasis is a chronic inflammatory disease and is associated with cardiovascular events. Little is known about subclinical myocardial dysfunction and potential changes in myocardial function during anti-inflammatory treatment in these patients. We prospectively studied left ventricular function in patients with severe psoriasis who initiated biologic therapy.

METHODS

Between November 1 2013 and May 31 2014 the study subjects underwent physical, laboratory and comprehensive echocardiographic examination at baseline and after 3 months of treatment. Pearson correlation coefficients and Student's t-test were applied to assess changes in diastolic function (defined as the E/e' ratio) and global longitudinal strain (GLS).

RESULTS

Eighteen patients with severe psoriasis treated with biologic therapy with a mean follow-up of 85.6 ± 18.2 days were included. The patients had a baseline psoriasis area and severity index (PASI) of 12.0 ± 4.1 and normal left ventricular ejection fraction [(LVEF) 56.3 ± 3.8%], diastolic dysfunction (E/e' 8.1 ± 2.1) and GLS (-16.8 ± 2.1%). At follow-up, an improvement (baseline vs. follow-up) of PASI (12.0 ± 4.1 vs. 2.7 ± 3.1, P < 0.001), E/e' (8.1 ± 2.1 vs. 6.7 ± 1.9, P ≤ 0.001) and GLS (-16.8 ± 2.1 vs. -18.3 ± 2.3%, P < 0.001) were recorded. No changes were demonstrated in LVEF (56.3 ± 3.8 vs. 56.8 ± 3.3%, P = 0.31), body mass index (30.9 ± 5.7 vs. 31.0 ± 5.8 kg/m(2) , P = 0.90), mean arterial blood pressure (103.1 ± 8.5 vs. 103.7 ± 10.8 mmHg, P = 0.74). Likewise, no changes were seen in total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, estimated glomerular filtration rate and glycosylated haemoglobin.

CONCLUSION

In patients with severe psoriasis treatment with biologic therapy was associated with improved PASI and amelioration of myocardial dysfunction.

Risk of thromboembolism and fatal stroke in patients with psoriasis and nonvalvular atrial fibrillation: a Danish nationwide cohort study

OBJECTIVES

Psoriasis is a chronic inflammatory disease that is associated with a prothrombotic state and cardiovascular disease, including atrial fibrillation and thromboembolism. We therefore evaluated the impact of psoriasis in patients with atrial fibrillation and the performance of the CHA2 DS2 VASc score in these patients.

DESIGN, SETTING AND PARTICIPANTS

The study comprised all Danish patients hospitalized with nonvalvular atrial fibrillation in the period 1997-2011 (n = 99,357). Follow-up started 7 days from discharge and excluded subjects treated with anticoagulation. Poisson regression adjusted for CHA2 DS2 VASc score was used to estimate the incidence rate ratios and 95% confidence intervals.

MAIN OUTCOME MEASURE

Hospitalization or death from thromboembolism.

RESULTS

Mean follow-up was 3.5, 3.1, and 2.8 years for patients with no psoriasis, mild psoriasis and severe psoriasis, respectively. Patients with psoriasis were younger compared to patients without psoriasis, but CHA2DS2VASc score did not differ between the three groups. Thromboembolism rates per 100 patient-years (95% confidence intervals) were 4.8 (4.7-4.9), 4.8 (4.2-5.4) and 6.1 (5.0-7.5) for patients with no psoriasis, mild psoriasis and severe psoriasis, respectively. Importantly, the observed thromboembolism rates in patients with severe psoriasis were markedly higher (2.6- to3.4-fold) than predicted by the CHA2 DS2 VASc score. Relative to no psoriasis, incidence rate ratios were 0.99 (0.87-1.11) and 1.27 (1.02-1.57) for mild and severe psoriasis, respectively. Correspondingly, incidence rate ratios for fatal stroke were 0.97 (0.80-1.12) and 1.51 (1.12-2.05).

CONCLUSIONS

In patients with nonvalvular atrial fibrillation not treated with oral anticoagulation, severe psoriasis was associated with increased risk of thromboembolism. In these patients, CHA2 DS2 VASc underestimated the risk of thromboembolism.

Structural and functional cardiac adaptations to 6 months of football training in untrained hypertensive men

We investigated the effects of 3 and 6 months of regular football training on cardiac structure and function in hypertensive men. Thirty-one untrained males with mild-to-moderate hypertension were randomized 2:1 to a football training group (n = 20) and a control group receiving traditional recommendations on healthy lifestyle (n = 11). Cardiac measures were evaluated by echocardiography. The football group exhibited significant (P < 0.05) changes in cardiac dimensions and function after just 3 months: Left ventricular (LV) end-diastolic volume increased from 104 ± 25 to 117 ± 29 mL. LV diastolic function improved measured as E/A ratio (1.15 ± 0.32 to 1.54 ± 0.38), early diastolic velocity, E' (11.0 ± 2.5 to 11.9 ± 2.6 cm/s), and isovolumetric relaxation time (74 ± 13 to 62 ± 13 ms). LV systolic function improved measured as longitudinal displacement (10.7 ± 2.1 to 12.1 ± 2.3 mm). Right ventricular function improved with respect to tricuspid annular plane systolic excursion (21.8 ± 3.2 to 24.5 ± 3.7 mm). Arterial blood pressure decreased in both groups, but significantly more in the football training group. No significant changes were observed in the control group. In conclusion, short-term football training improves LV diastolic function in untrained men with mild-to-moderate arterial hypertension. Furthermore, it may improve longitudinal systolic function of both ventricles. The results suggest that football training has favorable effects on cardiac function in hypertensive men.

Cardiovascular adaptations to 4 and 12 months of football or strength training in 65- to 75-year-old untrained men

The study examined the effects of 1 year of football or strength training on cardiovascular function in 65- to 75-year-old men. Twenty-six untrained men (age: 68.2 ± 3.2 years) were randomized to football training (FTG; n = 9), strength training (STG; n = 9), or control (CG; n = 8). In FTG, left ventricular (LV) internal diastolic diameter, end-diastolic volume, and mass index were 8%, 21%, and 18% higher (P < 0.01), respectively, after 12 months, with no changes in STG and CG. After 12 months, LV ejection fraction was increased (P < 0.05) by 8% and 5% in FTG and STG, respectively, and systolic longitudinal two-dimensional strain by 8% and 6%, whereas right ventricular systolic function improved (P < 0.05) by 22% in FTG, but not in STG and CG. In FTG, LV diastolic mitral inflow (E/A) ratio and peak early diastolic velocity (E') improved (P < 0.05) by 25% and 12%, respectively, after 12 months, with no changes in STG and CG. In FTG, maximum oxygen uptake was 16% and 18% higher (P < 0.001) after 4 and 12 months, respectively, and resting heart rate was 6 and 8 beats per minute lower (P < 0.001), respectively, with no changes in STG and CG. In conclusion, football training elicited superior cardiovascular effects compared with strength training in elderly untrained men.

A preliminary study: effects of football training on glucose control, body composition, and performance in men with type 2 diabetes

The effects of regular football training on glycemic control, body composition, and peak oxygen uptake (VO₂ peak) were investigated in men with type 2 diabetes mellitus (T2DM). Twenty-one middle-aged men (49.8 ± 1.7 years ± SEM) with T2DM were divided into a football training group (FG; n = 12) and an inactive control group (CG; n = 9) during a 24-week intervention period (IP). During a 1-h football training session, the distance covered was 4.7 ± 0.2 km, mean heart rate (HR) was 83 ± 2% of HRmax, and blood lactate levels increased (P < 0.001) from 2.1 ± 0.3 to 8.2 ± 1.3 mmol/L. In FG, VO₂ peak was 11% higher (P < 0.01), and total fat mass and android fat mass were 1.7 kg and 12.8% lower (P < 0.001), respectively, after IP. After IP, the reduction in plasma glucose was greater (P = 0.02) in FG than the increase in CG, and in FG, GLUT-4 tended to be higher (P = 0.072) after IP. For glycosylated hemoglobin (HbA1), an overall time effect (P < 0.01) was detected after 24 weeks. After IP, the number of capillaries around type I fibers was 7% higher (P < 0.05) in FG and 5% lower (P < 0.05) in CG. Thus, in men with T2DM, regular football training improves VO₂ peak, reduces fat mass, and may positively influence glycemic control.

'Short-term treatment with methotrexate does not affect microvascular endothelial function in patients with psoriasis'

BACKGROUND

Psoriasis is associated with increased risk of cardiovascular disease (CVD), possibly due to chronic low-grade systemic inflammation. Systemic anti-inflammatory treatment might reduce the risk of CVD.

OBJECTIVE

Our aim was to investigate if short-term treatment with methotrexate influences microvascular endothelial function (MEF), an early surrogate marker of atherosclerosis, in patients with psoriasis.

METHODS

We prospectively studied a hospital cohort of patients with psoriasis. Measurements of MEF were performed with the Endo-PAT2000© device at baseline and after 8-10 weeks of treatment with methotrexate. At the same time points, we recorded anamnestic information, measured body mass index (BMI), waist and hip circumferences and blood pressure, and drew blood samples (lipid profile, HbA1 and hs-CRP). Psoriasis severity was evaluated by psoriasis area and severity index (PASI) and the dermatology life quality index (DLQI).

RESULTS

A total of 32 patients with psoriasis were included. Median age was 46 (range 18-82) years, and 50% were men. Twenty-seven patients completed the study. After 8-10 weeks, median PASI had decreased significantly by 6.2 (from 9.8 to 3.6), and DLQI had decreased by 7 (from 9 to 2). No significant changes were observed in MEF, expressed by reactive hyperaemia index and augmentation index. Also, we saw no significant changes in BMI, waist-hip ratio, blood pressure and blood samples.

CONCLUSION

Short-term treatment with methotrexate did not affect MEF in patients with psoriasis. Further studies are warranted.

Cardiovascular function is better in veteran football players than age-matched untrained elderly healthy men

The aim of the study was to determine whether lifelong football training may improve cardiovascular function, physical fitness, and body composition. Our subjects were 17 male veteran football players (VPG; 68.1 ± 2.1 years) and 26 healthy age-matched untrained men who served as a control group (CG; 68.2 ± 3.2 years). Examinations included measurements of cardiac function, microvascular endothelial function [reactive hyperemic index (RHI)], maximum oxygen uptake (VO2max), and body composition. In VPG, left ventricular (LV) end-diastolic volume was 20% larger (P < 0.01) and LV ejection fraction was higher (P < 0.001). Tissue Doppler imaging revealed an augmented LV longitudinal displacement, i.e., LV shortening of 21% (P < 0.001) and longitudinal 2D strain was 12% higher (P < 0.05), in VPG. In VPG, resting heart rate was lower (6 bpm, P < 0.05), and VO2max was higher (18%, P < 0.05). In addition, RHI was 21% higher (P < 0.05) in VPG. VPG also had lower body mass index (P < 0.05), body fat percentage, total body fat mass, android fat percentage, and gynoid fat percentage (all P < 0.01). Lifelong participation in football training is associated with better LV systolic function, physical fitness, microvascular function, and a healthier body composition. Overall, VPG have better cardiovascular function compared with CG, which may reduce their cardiovascular morbidity and mortality.

Cardiovascular disease event rates in patients with severe psoriasis treated with systemic anti-inflammatory drugs: a Danish real-world cohort study

OBJECTIVES

Psoriasis is a chronic inflammatory disorder associated with cardiovascular morbidity and mortality. Systemic anti-inflammatory drugs, including biological agents, are widely used in the treatment of patients with moderate to severe psoriasis and may attenuate the risk of cardiovascular disease events. We therefore examined the rate of cardiovascular disease events in patients with severe psoriasis treated with systemic anti-inflammatory drugs.

DESIGN, SETTING AND PARTICIPANTS

Individual-level linkage of nationwide administrative databases was used to assess the event rates associated with use of biological agents, methotrexate or other therapies, including retinoids, cyclosporine and phototherapy, in Denmark from 2007 to 2009.

MAIN OUTCOME MEASURE

Death, myocardial infarction and stroke.

RESULTS

A total of 2400 patients with severe psoriasis, including 693 patients treated with biological agents and 799 treated with methotrexate, were identified. Incidence rates per 1000 patient-years and 95% confidence intervals (CIs) for the composite endpoint were 6.0 (95% CI 2.7-13.4), 17.3 (95% CI 12.3-24.3) and 44.5 (95% CI 34.6-57.0) for patients treated with biological agents, methotrexate and other therapies, respectively. Age- and sex-adjusted hazard ratios (HRs) were 0.28 (95% CI 0.12-0.64) and 0.65 (95% CI 0.42-1.00) for patients treated with biological agents and methotrexate, respectively, using other therapies as the reference cohort. Corresponding HRs for a secondary composite endpoint of cardiovascular death, myocardial infarction and stroke were 0.48 (95% CI 0.17-1.38) and 0.50 (95% CI 0.26-0.97).

CONCLUSION

In this nationwide study of patients with severe psoriasis, systemic anti-inflammatory treatment with biological agents or methotrexate was associated with lower cardiovascular disease event rates compared to patients treated with other anti-psoriatic therapies.

Prognosis following first-time myocardial infarction in patients with psoriasis: a Danish nationwide cohort study

OBJECTIVES

The magnitude of cardiovascular risk associated with psoriasis has been debated and the prognostic impact of psoriasis following myocardial infarction (MI) is unknown. Therefore, we investigated the risk of mortality and adverse cardiovascular events in patients with psoriasis following first-time MI.

DESIGN, SETTING AND PARTICIPANTS

Cohort study of the entire Danish population including all individuals who experienced first-time MI during the period 2002-2006. Multivariable Cox regression models were used to assess the post-MI prognostic impact of psoriasis. Main outcome measures.  All-cause mortality and a composite cardiovascular end-point of recurrent MI, stroke and cardiovascular death.

RESULTS

A total of 462 patients with psoriasis and 48 935 controls (mean age 69.5 and 70.6 years, respectively) were identified with first-time MI during the study period. The mean follow-up was 19.5 months [standard deviation (SD) 16.5] for patients with psoriasis and 22 .0 months (SD 18.7) for those without psoriasis. Incidence rates (IRs) per 1000 patient-years for all-cause mortality were 119.4 [95% confidence interval (CI) 117.2-138.3] and 138.3 (95% CI 114.1-167.7) for patients without and with psoriasis, respectively, and the adjusted hazard ratio (HR) associated with psoriasis was 1.18 (95% CI 0.97-1.43). For the composite end-point, the IRs were 149.7 (95% CI 147.1-152.4) and 185.6 (95% CI 155.8-221.0) for patients without and with psoriasis, respectively, with an HR of 1.26 (95% CI 1.04-1.54) for patients with psoriasis.

CONCLUSION

This first study of the impact of psoriasis on prognosis after first-time MI indicated a significantly impaired prognosis in patients with psoriasis. Further studies of this novel association are warranted.

Bleeding risk in 'real world' patients with atrial fibrillation: comparison of two established bleeding prediction schemes in a nationwide cohort

BACKGROUND

Oral anticoagulation (OAC) in patients with atrial fibrillation (AF) is a double-edged sword, because it decreases the risk of stroke at the cost of an increased risk of bleeding. We compared the performance of a new bleeding prediction scheme, HAS-BLED, with an older bleeding prediction scheme, HEMORR(2)HAGES, in a cohort of 'real-world' AF patients.

METHODS

By individual-level-linkage of nationwide registers, we identified all patients (n = 118,584) discharged with non-valvular AF in Denmark during the period 1997-2006, with and without OAC. Major bleeding rates during 1 year of follow-up were determined, and the predictive capabilities of the two schemes were compared by c-statistics. The risk of bleeding associated with individual risk factors composing HAS-BLED was estimated using Cox proportional-hazard analyses.

RESULTS

Of AF patients receiving OAC (n = 44,771), 34.8% and 47.3% were categorized as 'low bleeding risk' by HAS-BLED and HEMORR(2)HAGES, respectively, and the bleeding rates per 100 person-years were 2.66 (95% confidence interval [CI], 2.40-2.94) and 3.06 (2.83-3.32), respectively. C-statistics for the two schemes were 0.795 (0.759-0.829) and 0.771 (0.733-0.806), respectively. The risk factors composing HAS-BLED were associated with varying risks, with a history of bleeding (hazard ratio [HR] 2.98; 95% CI 2.68-3.31) and being elderly (HR 1.93; 95% CI 1.71-2.18) being associated with the highest risks. Comparable results were found in AF patients not receiving OAC (n = 77,813).

CONCLUSIONS

In an unselected nationwide cohort of hospitalized patients with atrial fibrillation, the HAS-BLED score performs similarly to HEMORR(2)HAGES in predicting bleeding risk but HAS-BLED is much simpler and easier to use in everyday clinical practise.

Psoriasis is associated with clinically significant cardiovascular risk: a Danish nationwide cohort study

OBJECTIVE

The magnitude of the cardiovascular risk from psoriasis and psoriatic arthritis is debated. We therefore investigated the psoriasis-related risk of adverse cardiovascular events and mortality.

DESIGN, SETTING AND SUBJECTS

We conducted a cohort study of the entire Danish population aged ≥18 years followed from 1997 to 2006 by individual-level linkage of nationwide registers. Psoriasis was defined by prescription claims and classified as severe if patients received hospital-based treatment. Time-dependent Poisson regression models were applied to assess cardiovascular risk in patients with psoriasis and psoriatic arthritis.

MAIN OUTCOME MEASURES

All-cause mortality, cardiovascular mortality and hospitalizations for myocardial infarction (MI), stroke and coronary revascularization were recorded.

RESULTS

A total of 34 371 patients with mild psoriasis and 2621 with severe psoriasis, including 607 with psoriatic arthritis, were identified and compared with 4 003 265 controls. The event rates and rate ratios (RRs) of all-cause mortality, cardiovascular death, MI, coronary revascularization, stroke and a composite of MI, stroke and cardiovascular death were increased in patients with psoriasis. The rate ratio increased with disease severity and decreased with age of onset. The overall RRs for the composite endpoint were 1.20 (95% confidence interval [CI] 1.14-1.25) and 1.58 (95% CI 1.36-1.82) for mild and severe psoriasis, respectively. The corresponding RRs for cardiovascular death were 1.14 (95% CI 1.06-1.22) and 1.57 (95% CI1.27-1.94). The risk was similar in patients with severe skin affection alone and those with psoriatic arthritis.

CONCLUSIONS

Psoriasis is associated with increased risk of adverse cardiovascular events and all-cause mortality. Young age, severe skin affection and/or psoriatic arthritis carry the most risk. Patients with psoriasis may be candidates for early cardiovascular risk factor modification.

Metformin treatment is associated with a low risk of mortality in diabetic patients with heart failure: a retrospective nationwide cohort study

AIMS/HYPOTHESIS

The safety of metformin in heart failure has been questioned because of a perceived risk of life-threatening lactic acidosis, though recent studies have not supported this concern. We investigated the risk of all-cause mortality associated with individual glucose-lowering treatment regimens used in current clinical practice in Denmark.

METHODS

All patients aged ≥ 30 years hospitalised for the first time for heart failure in 1997-2006 were identified and followed until the end of 2006. Patients who received treatment with metformin, a sulfonylurea and/or insulin were included and assigned to mono-, bi- or triple therapy groups. Multivariable Cox proportional hazard regression models were used to assess the risk of all-cause mortality.

RESULTS

A total of 10,920 patients were included. The median observational time was 844 days (interquartile range 365-1,395 days). In total, 6,187 (57%) patients died. With sulfonylurea monotherapy used as the reference, adjusted hazard ratios for all-cause mortality associated with the different treatment groups were as follows: metformin 0.85 (95% CI 0.75-0.98, p = 0.02), metformin + sulfonylurea 0.89 (95% CI 0.82-0.96, p = 0.003), metformin + insulin 0.96 (95% CI 0.82-1.13, p = 0.6), metformin + insulin + sulfonylurea 0.94 (95% CI 0.77-1.15, p = 0.5), sulfonylurea + insulin 0.97 (95% CI 0.86-1.08, p = 0.5) and insulin 1.14 (95% CI 1.06-1.20, p = 0.0001).

CONCLUSIONS/INTERPRETATION

Treatment with metformin is associated with a low risk of mortality in diabetic patients with heart failure compared with treatment with a sulfonylurea or insulin.

Long-term musculoskeletal and cardiac health effects of recreational football and running for premenopausal women

We examined long-term musculoskeletal and cardiac adaptations elicited by recreational football (FG, n=9) and running (RG, n=10) in untrained premenopausal women in comparison with a control group (CG, n=9). Training was performed for 16 months ( approximately 2 weekly 1-h sessions). For FG, right and left ventricular end-diastolic diameters were increased by 24% and 5% (P<0.05), respectively, after 16 months. Right ventricular systolic function measured by tricuspid annular plane systolic excursion (TAPSE) increased (P<0.05) in FG after 4 months and further (P<0.05) after 16 months (15% and 32%, respectively). In RG and CG, cardiac structure, E/A and TAPSE remained unchanged. For FG, whole-body bone mineral density (BMD) was 2.3% and 1.3% higher (P<0.05) after 16 months, than after 4 and 0 months, respectively, with no changes for RG and CG. FG demonstrated substantial improvements (P<0.05) in fast (27% and 16%) and slow (16% and 17%) eccentric muscle strength and rapid force capacity (Imp30ms: 66% and 65%) after 16 months compared with 4 and 0 months, with RG improving Imp30ms by 64% and 46%. In conclusion, long-term recreational football improved muscle function, postural balance and BMD in adult women with a potential favorable influence on the risk of falls and fractures. Moreover, football training induced consistent cardiac adaptations, which may have implications for long-term cardiovascular health.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Injury Molecule 1 (KIM1) in patients with diabetic nephropathy: a cross-sectional study and the effects of lisinopril

AIMS

Our aim was to evaluate the markers of tubulointerstitial damage, neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule1 (KIM1) in Type 1 diabetic patients with different levels of albuminuria and in control subjects. In addition, the effect of renoprotective treatment on urinary NGAL was evaluated in diabetic nephropathy.

METHODS

This was a cross-sectional study in 58 normoalbuminuric (u-albumin <30 mg/24 h), 45 microalbuminuric (30-300 mg/24 h) and 45 macroalbuminuric (>300 mg/24 h) Type 1 diabetic patients and 55 non-diabetic control subjects. Furthermore, in a second study, urine-NGAL was measured in a randomized cross-over study of 56 Type 1 diabetic patients with diabetic nephropathy treated with lisinopril 20, 40 and 60 mg daily.

RESULTS

  Urine-NGAL levels were [geometric mean (95% CI)]: control subjects 74 (52-104) (pg/mmol creatinine), normoalbuminuric 146 (97-221), microalbuminuric 222 (158-312) and macroalbuminuric group 261 (175-390). Urine-NGAL increased significantly from the normo- to the micro- and further to the macroalbuminuric group (P<0.05). Urine-NGAL was higher in normoalbuminuric vs. control subjects (P<0.01). Plasma-NGAL was significantly higher in the normoalbuminuric and macroalbuminuric groups than in the control group. Urine-KIM1 was higher in all diabetic groups than in the control group (P<0.001), with no difference between diabetic groups. During lisinopril treatment, urine-NGAL was reduced (95% CI) 17% (11-50) (not significant).

CONCLUSIONS

Urine-NGAL and urine-KIM1 (u-KIM1) are elevated in Type1 diabetic patients, with or without albuminuria, indicating tubular damage at an early stage. Urine-NGAL increases significantly with increasing albuminuria. The ACE inhibitor lisinopril reduced urine-NGAL, but this was not statistically significant.

Interaction of the chaperone calreticulin with proteins and peptides of different structural classes

The interaction of calreticulin with native and denatured forms and polypeptides in proteolytic digests of proteins representing structural classes of all-alpha-helix (hemoglobin, serum albumin), all-beta-sheet (IgG) and alpha-helix + beta-sheets (lysozyme, ovalbumin) was investigated. The binding of calreticulin to denatured proteins was found to depend on conformation and structural class of the protein. No interaction was observed with the native proteins, whereas binding was seen for the denatured proteins, the order of interaction being lysozyme = IgG > ovalbumin >> hemoglobin = serum albumin. Moreover, the interaction between calreticulin and the heat-denatured proteins depended on the temperature and time used for denaturation and the degree of proteolytic fragmentation. Calreticulin bound well to peptides in proteolytic digests from protease K or chymotrypsin treatment of lysozyme, IgG and ovalbumin but weakly or not at all to peptides in proteolytic digests of hemoglobin and serum albumin. Synthetic peptides from lysozyme and ovalbumin confirmed binding to hydrophobic peptides from these proteins. These results show that calreticulin has the ability to interact with denatured and fragmented forms of proteins with a preference for beta-strand structure and hydrophobicity.

Beneficial effects of recreational football on the cardiovascular risk profile in untrained premenopausal women

The present study examined the cardiovascular health effects of 16 weeks of recreational football training in untrained premenopausal women in comparison with continuous running training. Fifty healthy women were matched and randomized to a football (FG, n=25) or a running (RG, n=25) group and compared with a control group with no physical training (CO, n=15). Training was performed for 1 h twice a week. After 16 weeks, systolic and diastolic blood pressure was reduced (P<0.05) in FG (7+/-2 and 4+/-1 mmHg) and systolic blood pressure was lowered (P<0.05) in RG (6+/-2 mmHg). After 16 weeks, resting heart rate was lowered (P<0.05) by 5+/-1 bpm both in FG and RG, and maximal oxygen uptake was elevated (P<0.05) by 15% in FG and by 10% in RG (5.0+/-0.7 and 3.6+/-0.6 mL/min/kg, respectively). Total fat mass decreased (P<0.05) by 1.4+/-0.3 kg in FG and by 1.1+/-0.3 kg in RG. After 16 weeks, pulse pressure wave augmentation index (-0.9+/-2.5 vs 4.2+/-2.4%), skeletal muscle capillarization (2.44+/-0.15 vs 2.07+/-0.05 cap/fib) and low-density lipoprotein/high-density lipoprotein cholesterol ratio were improved (P<0.05) in FG, but not altered in RG. No changes were observed in CO. In conclusion, regular recreational football training has significant favorable effects on the cardiovascular risk profile in untrained premenopausal women and is at the least as efficient as continuous running.

Improvement of systolic and diastolic heart function after physical training in sedentary women

The present study examined the cardiac effects of football training and running for inactive pre-menopausal women by standard echocardiography and tissue Doppler imaging. Thirty-seven subjects were randomized to two training groups (football: FG; n=19; running; RG; n=18) training 1 h with equal average heart rates twice a week for 16 weeks and compared with a matched inactive control group (CG; n=10). During the training period, left ventricular end-diastolic volume increased by 13% in FG and 11% in RG (P<0.05). Left ventricular posterior wall thickness increased in FG from 8.5+/-1.4 to 9.0+/-1.3 mm (P<0.05). Right ventricle diameter increased by 12% in FG and 10% in RG (P<0.05). Tissue Doppler imaging demonstrated increased left ventricular systolic and diastolic performances in both training groups. Peak systolic velocity increased by 26% in FG and 17% in RG (P<0.05) and left ventricular longitudinal displacement increased in both groups by 13% (P<0.05). Isovolumetric relaxation time decreased significantly more in FG than in RG (26% vs 14%, respectively P<0.05). In conclusion, 16 weeks of football and running exercise training induced significant changes of cardiac dimensions and had favorable effects on both left ventricular systolic and diastolic function. These training-induced cardiac adaptations appeared to be more consistent after football training compared with running.

Interaction of calreticulin with amyloid beta peptide 1-42

The interaction of calreticulin with amyloid beta (Abeta) was investigated using solid phase and solution binding assays. Calreticulin bound Abeta 1-42 in a time and concentration dependent fashion. The binding was optimal at pH 5 and was stimulated by Ca2+ and inhibited by Zn2+ at pH 7. Interaction took place through the hydrophobic C-terminus of Abeta 1-42 and the polypeptide binding site of calreticulin. The results are discussed in the light of a reported role of calreticulin as a cell surface scavenger receptor.

Pregnancy-associated plasma protein A in a large cohort of Type 1 diabetic patients with and without diabetic nephropathy-a prospective follow--up study

AIM

Pregnancy-associated plasma protein A (PAPP-A) has been implicated in the aetiology of acute coronary syndromes and carotid and peripheral artherosclerosis. Diabetic nephropathy is characterized by increased cardiovascular risk. We investigated the prognostic value of PAPP-A in a large cohort of Type 1 diabetic patients.

METHODS

In a prospective observational follow-up study, 197 Type 1 diabetic patients with diabetic nephropathy and a matched group of 178 patients with normoalbuminuria were followed for 10.1 (0-10.3) years. PAPP-A was determined at baseline.

RESULTS

In patients with diabetic nephropathy, plasma PAPP-A was elevated 3.6 (0.4-51.1) mIU/l [median (range)] vs. 2.1 (0.4-46.6) mIU/l in normoalbuminuric patients, P < 0.0001. For acute coronary syndromes, a PAPP-A threshold of 10 mIU/l has been suggested. Thirty-seven patients were above the threshold and of these 13 patients (35%) died, compared with 60 of 338 patients (18%) below the threshold; log rank test P = 0.007. PAPP-A significantly predicted mortality after adjustment for presence of nephropathy; hazard ratio for dying when PAPP-A was above the threshold 2.1 (95% CI 1.13-3.9); P = 0.019. After adjusting for traditional risk factors, the results were attenuated. When only patients with nephropathy were analysed, PAPP-A was significantly predictive of all-cause mortality [P = 0.008; 2.43 (1.26-4.67)] in unadjusted analysis. After adjustment, the predictive value of PAPP-A for all-cause mortality was attenuated (P = 0.064).

CONCLUSION

We find PAPP-A to be associated with increased mortality in Type 1 diabetic patients with nephropathy in unadjusted analysis. After adjustment for traditional risk factors, the prognostic value of PAPP-A was no longer significant.

Second-generation nanofiltered plasma-derived mannan-binding lectin product: process and characteristics

BACKGROUND AND OBJECTIVES

Mannan-binding lectin (MBL) is an important component of the innate immune defence; it binds to carbohydrate structures on pathogenic micro-organisms resulting in complement activation and opsonization. Individuals with low MBL levels are at risk of recurrent and severe infections. Substitution therapy with plasma-derived MBL is a promising treatment of diseases associated with MBL deficiency. A first-generation MBL product has been shown to be safe and well tolerated, and patients have benefited from MBL treatment. Following is a description of the development of a nanofiltered second-generation MBL product from Cohn fraction III, with the use of a new affinity matrix for MBL purification and the characteristics of this improved product.

MATERIALS AND METHODS

Carbohydrate-based gels were comparatively screened as affinity matrices. MBL was extracted from fraction III, and affinity purified on a Superdex 200 pg column. The eluted material underwent two virus reduction steps: filtration through Planova 20N and solvent/detergent treatment. It was further purified by anion-exchange and gel-filtration chromatography. The affinity eluate and the final MBL fraction were characterized by protein chemical, immunological, and functional assays.

RESULTS

In production scale, Superdex 200 pg was found to be superior to other carbohydrate-based matrices, and MBL was affinity purified from fraction III with a yield of 70%. The viral safety was increased by performing a nanofiltration of the affinity eluate through Planova 20N with a minimal loss of MBL. The purity of the final MBL fraction was 53% excluding the MBL-associated serine proteases (MASP). The product consisted of high-oligomeric MBL, with two dominating forms, and with MASP-1, -2, -3 and 19 kDa MBL-associated protein (MAp19). Only a few protein impurities were present, the major being alpha2-macroglobulin. MBL formed complexes with alpha2-macroglobulin bridged by MASP-1 covalently attached to the latter. The functional activity, assessed by mannan-binding activity and opsonic function, was intact, whereas half of the C4 activating capacity was lost during the production process.

CONCLUSION

A second-generation MBL process was developed with an average yield of 50%. It was possible to nanofilter the MBL-MASP complexes through Planova 20N with only a minor loss resulting in an increased safety profile of this MBL product.

New indolicidin analogues with potent antibacterial activity*

Indolicidin is a 13-residue antimicrobial peptide amide, ILPWKWPWWPWRR-NH2, isolated from the cytoplasmic granules of bovine neutrophils. Indolicidin is active against a wide range of microorganisms and has also been shown to be haemolytic and cytotoxic towards erythrocytes and human T lymphocytes. The aim of the present paper is two-fold. First, we examine the importance of tryptophan in the antibacterial activity of indolicidin. We prepared five peptide analogues with the format ILPXKXPXXPXRR-NH2 in which Trp-residues 4,6,8,9,11 were replaced in all positions with X = a single non-natural building block; N-substituted glycine residue or nonproteinogenic amino acid. The analogues were tested for antibacterial activity against both Staphylococcus aureus American type culture collection (ATCC) 25923 and Escherichia coli ATCC 25922. We found that tryptophan is not essential in the antibacterial activity of indolicidin, and even more active analogues were obtained by replacing tryptophan with non-natural aromatic amino acids. Using this knowledge, we then investigated a new principle for improving the antibacterial activity of small peptides. Our approach involves changing the hydrophobicity of the peptide by modifying the N-terminus with a hydrophobic non-natural building block. We prepared 22 analogues of indolicidin and [Phe(4,6,8,9,11)] indolicidin, 11 of each, carrying a hydrophobic non-natural building block attached to the N-terminus. Several active antibacterial analogues were identified. Finally, the cytotoxicity of the analogues against sheep erythrocytes was assessed in a haemolytic activity assay. The results presented here suggest that modified analogues of antibacterial peptides, containing non-natural building blocks, are promising lead structures for developing future therapeutics.

Spironolactone inhibits production of proinflammatory cytokines, including tumour necrosis factor-alpha and interferon-gamma, and has potential in the treatment of arthritis

Evidence suggests that spironolactone, an aldosterone antagonist, has effects on many cell types independent of its binding to cytosolic mineralocorticoid receptors. We tested the effects of spironolactone on ex vivo-activated human blood leucocytes using gene expression analyses (GeneChip, 12,000 genes) and enzyme immunoassay for quantitating secreted pro- and anti-inflammatory cytokines. Furthermore, to evaluate the safety and efficacy of spironolactone as an anti-inflammatory drug 21 patients with rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA) or other arthritides were treated for up to 22 months with 1-3 mg/kg/day. Spironolactone, at in vivo attainable doses, markedly suppressed transcription of several proinflammatory cytokines and, accordingly, inhibited release of tumour necrosis factor, lymphotoxin, interferon-gamma, granulocyte-macrophage colony-stimulating factor and interleukin 6 (70-90% inhibition). Release of these cytokines was also suppressed when testing whole blood from RA patients receiving 50 mg spironolactone twice daily, indicating that pharmaceutical use of the drug may suppress the release of inflammatory cytokines. Spironolactone therapy was generally well tolerated, although treatment had to be stopped in two adults on concomitant methotrexate therapy. Sixteen patients (76%) responded favourably. American College of Rheumatology criteria (ACR)20 or better was achieved in six of nine RA patients; four reached ACR70. Eight of nine JIA patients improved. In conclusion, spironolactone inhibits production of several proinflammatory cytokines considered to be of pathogenic importance in many immunoinflammatory diseases and shows positive effect in patients with chronic arthritis. Its effect as an anti-inflammatory drug should be explored, because prolonged spironolactone therapy is reasonably safe and economically attractive compared with many modern anti-inflammatory therapies.

Preparation of bioconjugates by solid-phase conjugation to ion exchange matrix-adsorbed carrier proteins

A solid-phase conjugation method utilizing carrier protein bound to an ion exchange matrix was developed. Ovalbumin was adsorbed to an anion exchange matrix using a batch procedure, and the immobilized protein was then derivatized with iodoacetic acid N-hydroxysuccinimid ester. The activated protein was conjugated with glutathione, the conjugation ratio determined by acid hydrolysis, and amino acid analysis performed with quantification of carboxymethyl cysteine. Elution of conjugates from the resin by a salt gradient revealed considerable heterogeneity in the degree of derivatization, and immunization experiments with the eluted conjugates showed that the more substituted conjugates gave rise to the highest titers of glutathione antibodies. Direct immunization with the conjugates adsorbed to the ion exchange matrix was possible and gave rise to high titers of glutathione antibodies. Conjugates of ovalbumin and various peptides were prepared in a similar manner and used for production of peptide antisera by direct immunization with the conjugates bound to the ion exchanger. Advantages of the method are its solid-phase nature, allowing fast and efficient reactions and intermediate washings, and the ability to release conjugates from the solid phase under mild conditions.

Diverse effects of inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase on the expression of VCAM-1 and E-selectin in endothelial cells

The expression of monocyte adhesion molecules, such as VCAM-1 (vascular cell adhesion molecule-1) and E-selectin, on the surface of the endothelium is an important step in the initiation and progression of atherosclerotic lesions. We hypothesized that the inhibition of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase in endothelial cells could influence the expression of VCAM-1 and E-selectin. Using cultured human umbilical vein endothelial cells, we found that mevastatin (0.1-1 microM) significantly reduced the expression of VCAM-1 protein in cells activated by tumour necrosis factor-alpha (TNF-alpha) for 7 h. In contrast, TNF-alpha-induced E-selectin protein expression was augmented after mevastatin treatment. Mevastatin inhibited the mRNA expression of both VCAM-1 and E-selectin in TNF-alpha-stimulated endothelial cells. The activity of the transcription factor nuclear factor-kappa B, which is known to regulate the transcription of VCAM-1 and E-selectin, was significantly reduced after incubation with mevastatin. Analysis of the time-dependent variation in the TNF-alpha-induced expression of E-selectin, and estimation of the rate of surface disappearance of E-selectin together with measurement of the amounts of E-selectin molecules secreted, indicated that mevastatin inhibited the surface removal of E-selectin. This is compatible with the observed increase in E-selectin expression after statin treatment. All observed effects of mevastatin were reversed by mevalonate, the product of the HMG-CoA reductase reaction. In conclusion, inhibition of HMG-CoA reductase in endothelial cells attenuates VCAM-1 expression, but increases E-selectin expression, after cytokine induction. These diverse effects are associated with changes in the transcriptional regulation of the two adhesion molecule genes and modulation of the surface removal of E-selectin.

Freunds adjuvant alone is antiatherogenic in apoE-deficient mice and specific immunization against TNFalpha confers no additional benefit

TNFalpha participates in the pathogenesis of atherosclerosis. The effect of immunization against TNFalpha on development of advanced vascular lesions in atherosclerosis-susceptible apoE-deficient mice was investigated. At 5-7 weeks of age, animals received immunization with either Freunds adjuvant and a recombinant antigenic TNFalpha molecule (TNF106), Freunds adjuvant alone, or no immunization. All mice received a Western-type high-fat diet for 12 weeks. Aortic sinus lesion area was determined by microscopic morphometry, the total aortic arch cholesterol content was determined by gas chromatography, and antibodies against TNFalpha, malondialdehyde-modified low density lipoprotein, or heat shock protein 60, were assessed by ELISAs. Immunization with TNF106 induced high-titered circulating antibodies against TNFalpha (n=23), and these antibodies were not detected in mice immunized with Freunds adjuvant alone (n=22), or in non-immunized control animals (n=25). After 12 weeks, the atherosclerotic lesion size was significantly reduced in immunized animals, whether they had been immunized with TNF106 or Freunds adjuvant alone, and the total lesional cholesterol content was decreased in mice immunized with TNF106. There were no correlations between circulating antibody titers and plaque size, total aortic arch cholesterol content, or plasma lipid levels, respectively. Administration of Freunds adjuvant alone can thus reduce formation of mature atherosclerotic lesions in apoE-deficient mice and this response is not modified by specific immunization against TNFalpha.

[Contrast echocardiography. Basic principles and clinical applications]

Recent advances in ultrasound technology and intravenous contrast agents have made it possible for contrast echocardiography to move from bench to bedside. Ultrasound contrast agents enhance endocardial border delineation and the Doppler signal, which may improve the diagnostic accuracy of echocardiography in selected patients. The most exciting feature of contrast echocardiography is its capability to achieve a quantitative assessment of myocardial perfusion, and the method may thus provide a range of clinical applications in patients with ischaemic heart disease.

Effects of L-arginine on vascular smooth muscle cell proliferation and apoptosis after balloon injury

Nitric oxide (NO) inhibits neointimal formation in experimental models of restenosis, but the mechanisms have not been fully elucidated. This study examined whether the beneficial effect of L-arginine, the physiological NO precursor, was associated with alteration of the apoptotic and proliferative activities of vascular smooth muscle cells (VSMCs) in the vessel wall after arterial injury. Balloon injury was performed in the rat carotid-artery injury model. Rats were treated with L-arginine (2.25% in the drinking water) or normal drinking water, and sacrificed at 1, 2 and 14 days postinjury. Apoptosis was assessed by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeling (TUNEL), and proliferation by proliferating cell nuclear antigen (PCNA) immunohistochemistry. Treatment with L-arginine increased the luminal area at 14 days postinjury (0.26 +/- 0.03 mm2 vs 0.14 +/- 0.04 mm2; p < 0.05), and this effect was attributable to a reduction in neointimal formation (0.11 +/- 0.03 mm2 vs 0.23 +/- 0.04 mm2; p < 0.05), while L-arginine did not affect vascular remodeling, as indicated by the total vessel area. The decreased neointimal area at 14 days after balloon injury contained a reduced percentage of TUNEL positive (0.1 +/- 0.1% vs 2.0 +/- 0.6%; p < 0.05), and PCNA positive (13.0 +/- 2.6% vs 27.2 +/- 5.9%; p < 0.05) nuclei, respectively. L-arginine did not influence the apoptotic or proliferative activities of VSMCs at earlier time points postinjury. The favourable effect of L-arginine in the rat model of arterial injury is associated with inhibition of VSMC proliferative activity in the vessel wall and is not explained by increased VSMC apoptosis.

Efficient protection against Mycobacterium tuberculosis by vaccination with a single subdominant epitope from the ESAT-6 antigen

We have investigated the vaccine potential of two peptides derived from the 6-kDa early secretory antigenic target (ESAT)-6 antigen in the mouse model of tuberculosis. The peptides were both strongly immunogenic in B6CBAF1 (H-2b,k) mice and primed recall responses of the same intensity after immunization. However, both tuberculosis infection and immunization with ESAT-6 resulted in responses focused towards ESAT-61-20. Multiple antigen peptide constructs as well as free peptides were emulsified with dimethyl dioctadecylammonium bromide/monophosphoryl lipid A/IL-2 and tested as experimental vaccines in an i.v. and aerosol model of tuberculosis in mice. The peptide were highly immunogenic and induced cellular responses of the same magnitude. However, only vaccines based on the subdominant ESAT-651-70 epitope promoted significant levels of protective immunity and the level of protection was equivalent to that achieved with ESAT-6 and BCG. These findings demonstrate the potential of peptide-based vaccines against tuberculosis and indicate that there is not direct correlation between the hierarchy of response to naturally processed peptides and their ability to induce protective immunity against Mycobacterium tuberculosis.

[Smoking cessation practice among Norwegian hospital physicians]

BACKGROUND

Limited data is available as to what extent Norwegian hospital doctors ask their patients about their smoking habits, and to what extent doctors offer their patients help in smoking cessation.

MATERIAL AND METHODS

A random sample of 1,025 hospital doctors was mailed a questionnaire. After 14 days a reminder letter was sent to non-responders; 76% of the doctors responded.

RESULTS

Altogether 98% of the doctors stated that they asked their patients with smoking-related disease about their smoking habits. In cases of non-smoking related disease, 73% of the doctors stated that they asked about the smoking habits of their patients (83% of female and 69% of male doctors). If doctors knew that a patient wanted to quit smoking, 25% of them stated that they often recommended nicotine replacement therapy. Less than 7% of the doctors regularly offered smoking cessation courses, handed out self-assistant material, or gave the patients other smoking cessation advice.

INTERPRETATION

The study indicates that doctors often ask their patients about their smoking habits, but there is clear potential for improvement as to the smoking cessation advice.

Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia

BACKGROUND

Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short episodes of acute myocardial ischemia. To evaluate this hypothesis myocardial 11C-acetate PET imaging was performed before and after acute repetitive myocardial ischemia.

METHODS AND RESULTS

In open chest dogs (n = 8), the left anterior descending coronary artery was occluded 4 times for 5 minutes alternating with 5 minutes of reperfusion. Before and after repetitive coronary occlusions, oxygen 15 water/oxygen 15 carbon monoxide (blood flow), and 11C-acetate (oxygen consumption) PET imaging were performed. Left ventricular regional systolic wall thickening was measured with sonomicrometry. Forty-five minutes after the ischemic episodes, systolic ventricular wall thickening was decreased by 90%, whereas myocardial blood flow was reduced by 21% compared with baseline values (P < .05). Ninety minutes after the ischemic episodes, estimated oxygen consumption was unaltered compared with the baseline level despite a sustained 70% decrease in the regional contractile function (P < .05).

CONCLUSIONS

Oxygen consumption estimated by 11C-acetate PET imaging is preserved after repeated episodes of acute myocardial ischemia despite a severe impairment of contractile function.

Apoptosis and formation of peroxynitrite in the lungs of patients with obliterative bronchiolitis

BACKGROUND

Obliterative bronchiolitis (OB) is the principal long-term complication of lung and heart-lung transplantation. OB is characterized histologically by inflammation, epithelial cell loss, fibrosis, and obliteration of the terminal airways. The contribution of apoptosis and peroxynitrite formation in OB was examined and assessed whether immunohistochemical markers of these reactions in transbronchial biopsy specimens were predictive of OB development.

METHODS

Pulmonary tissue samples from lung transplant recipients with OB (n = 5) or without OB (control group; n = 7) were investigated by in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and nitrotyrosine immunohistochemistry. Furthermore, TUNEL and nitrotyrosine expression was compared between matched transbronchial biopsy specimens from the two patient groups.

RESULTS

Sections with active OB displayed a significantly increased number of TUNEL-positive epithelial cells and macrophages compared with very little TUNEL in control specimens. TUNEL was almost absent in inactive OB. Nitrotyrosine was detected in all samples of pulmonary tissue, but nitrotyrosine expression was more intense in patients with active OB. There was no apparent temporospatial correlation of TUNEL and nitrotyrosine expression, and in matched transbronchial specimens, these immunohistochemical markers failed to identify patients with imminent risk of developing OB.

CONCLUSIONS

Apoptosis contributes to the pathophysiology of active OB but is apparently not directly paralleled by tissue peroxynitrite formation. In transbronchial biopsy specimens, markers of apoptosis and peroxynitrite formation are not valid predictors of OB and more studies are required to deliniate the role of these mechanisms in pulmonary allograft rejection.

ACE-inhibition promotes apoptosis after balloon injury of rat carotid arteries

OBJECTIVE

Angiotensin II stimulates vascular smooth muscle cell (VSMC) growth, and is considered to be an important mediator of intimal thickening after vascular injury. Recent evidence has indicated that VSMC apoptosis plays a major role in the response to balloon injury, and we therefore examined the effect of angiotensin converting enzyme (ACE)-inhibition on VSMC apoptosis and vascular lesion formation in the rat model of balloon injury.

METHODS

Male Sprague-Dawley rats were subjected to carotid artery balloon injury and randomised to a standard diet or a diet supplemented with 1 mg/ml captopril in the drinking water. Animals were sacrificed 2 and 14 days after injury for assessment of apoptosis and proliferation by in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) and proliferating cell nuclear antigen (PCNA) immunohistochemistry, respectively. At 14 days post injury, vessel cross-sections were subjected to microscopic morphometry and total cell numbers were determined.

RESULTS

At 2 days after balloon injury, captopril-treated animals displayed a significant increase in the percentage of TUNEL-positive VSMCs in the medial area (12 +/- 4% vs. 1 +/- 1%; P < 0.05) as compared to controls. This increase in early apoptosis was associated with decreased intimal cellularity 14 days post injury (238 +/- 47 cells/cross-section vs. 449 +/- 75 cells/cross-section; P < 0.05), and a reduction of neointimal formation (0.13 +/- 0.02 mm2 vs. 0.23 +/- 0.04 mm2; P < 0.05). The fraction of PCNA-positive VSMCs per cross-section 2 or 14 days after injury was not significantly altered by captopril administration.

CONCLUSION

Captopril inhibits neointimal formation in the rat model of arterial injury by mechanisms involving induction of VSMC apoptosis.

Pentoxifylline inhibits neointimal formation and stimulates constrictive vascular remodeling after arterial injury

Pentoxifylline (PTX) is a phosphodiesterase inhibitor used in the treatment of peripheral vascular disease, and this agent can suppress inflammatory vascular damage. Inflammation has been implicated in vascular lesion formation, and we examined the effects of PTX in a model of arterial injury. Sprague-Dawley rats were treated with intraperitoneal PTX (75 mg/kg/day) or saline starting 3 days before carotid balloon injury, and killed 24 h or 14 days later. Carotid arteries were analyzed by cross-sectional morphometry, immunostaining for proliferating cell nuclear antigen (PCNA) and subjected to terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL). Moreover, the effects of PTX on vascular smooth-muscle cell (VSMC) migration and production of collagen types I, IV, and VI were examined in vitro. At 14 days after balloon injury, PTX reduced the neointimal area (0.074+/-0.001 vs. 0.172+/-0.003 mm2; p<0.001), media area (0.143+/-0.001 vs. 0.176+/-0.001 mm2; p<0.01), intima/media ratio (0.50+/-0.02 vs. 0.99+/-0.12; p<0.001), and total vessel area (0.601+/-0.010 vs. 0.744+/-0.011 mm2; p<0.01). The lumen area, PCNA expression, and TUNEL were similar in the two treatment groups, whereas the neointimal cell density was increased by PTX (3,476+/-504 cells/mm2 vs. 2,215+/-232 cells/mm2; p<0.05). In vitro, PTX inhibited VSMC production of collagen type I in a concentration-dependent manner and did not influence VSMC migration. We conclude that PTX inhibits neointimal formation and induces constrictive vascular remodeling in the rat model of balloon injury by mechanisms involving decreased VSMC collagen type I production.

[Cholesterol ester transfer protein. A major player in cholesterol metabolism]

Plasma cholesterol transfer protein (P-CETP) plays a central role in cholesterol metabolism by pronroting transfer of cholesteryl esters from high density lipoprotein (HDL) to very low density lipoproteins in exchange for triglycerides. The CETP-reaction may hereby be a critical factor in reverse cholesterol transport, i.e., the transfer of cholesterol from peripheral tissues to the river for catabolism. Human genetic CETP deficiency is associated with increased P-HDL-cholesterol, whereas CEPT transgenic mice display decreased P-HDL-cholesterol. The effects of CETP on atherogenesis are currently unpredictable, and they are likely to depend on the metabolic context. However, the presence of specific polymorphisms in the CETP gene may be of clinical importance, and CETP should be considered among the factors relevant for differentiation of dyslipidemic syndromes associated with susceptibility to and protection from atherosclerotic disease.

Aminoguanidine induces constrictive vascular remodeling and inhibits smooth muscle cell death after balloon injury

We examined the effects of aminoguanidine, an inhibitor of inducible nitric oxide synthase, in the rat model of balloon injury. Arteries were assessed by histomorphometry, and vascular smooth muscle cell death and proliferation were examined 24 h and 14 days after balloon injury by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) of fragmented DNA and expression of proliferating cell nuclear antigen, respectively. Aminoguanidine decreased the luminal area 14 days after balloon injury (0.19+/-0.04 mm2 vs. 0.35+/-0.02 mmr2; P < 0.005), and this effect was attributable to reduction of the total vessel area, i.e., constrictive vascular remodeling (0.42+/-0.03 mm2 vs. 0.55+/-0.03 mm2; P < 0.005). At 24 h after injury, the percentage of TUNEL-positive cells in the medial layer was reduced by aminoguanidine (2.0+/-1.0% vs. 17.3+/-5.4%; P < 0.05), and the percentage of proliferating cells was increased (18.4+/-5.5% vs. 4.9+/-2.2%; P < 0.05). Aminoguanidine did not influence the density of VSMC nuclei in the injured artery wall, systemic blood pressure or endothelium-dependent vasorelaxation. We conclude, that in the rat model of balloon injury, aminoguanidine induces luminal loss by constrictive vascular remodeling in association with reduced early VSMC death and increased proliferation.

Apoptosis in acute pulmonary allograft rejection and cytomegalovirus infection

Apoptosis is a form of programmed cell death, characterized by activation of endonucleases that cleave DNA into oligonucleosomal fragments, which can be identified by in situ terminal deoxyribonucleotide transferase-mediated dUTP nick-end labeling (TUNEL). This process has recently been implicated in cardiac and hepatic allograft rejection, and we investigated its contribution to acute pulmonary allograft rejection and cytomegalovirus (CMV) pneumonitis by in situ TUNEL of transbronchial biopsy specimens. In situ TUNEL was performed on 70 transbronchial biopsy samples collected from 25 pulmonary allograft recipients for diagnosis of acute rejection or CMV pneumonitis, and the number of apoptotic nuclei/mm2 was correlated with the rejection grade (International Society of Heart and Lung Transplantation classification). During acute pulmonary allograft rejection, apoptotic nuclei were demonstrated in pulmonary parenchymal cells and mononuclear infiltrating cells, and the number of apoptotic cells was positively correlated with the rejection grade. In addition, a marked increase in the density of apoptotic cells was found in pulmonary allografts with CMV pneumonitis. We conclude that apoptosis contributes to cell death during acute pulmonary allograft rejection and CMV infection.