Clinical Response and Remission in Patients With Severe Asthma Treated With Biologic Therapies

BACKGROUND

The development of novel targeted biologic therapies for severe asthma has provided an opportunity to consider remission as a new treatment goal.

RESEARCH QUESTION

How many patients with severe asthma treated with biologic therapy achieve clinical remission, and what predicts response to treatment?

STUDY DESIGN AND METHODS

The Danish Severe Asthma Register is a nationwide cohort including all adult patients receiving biologic therapy for severe asthma in Denmark. This observational cohort study defined "clinical response" to treatment following 12 months as a ≥ 50% reduction in exacerbations and/or a ≥ 50% reduction in maintenance oral corticosteroid dose, if required. "Clinical remission" was defined by cessation of exacerbations and maintenance oral corticosteroids, as well as a normalization of lung function (FEV1 > 80%) and a six-question Asthma Control Questionnaire score ≤ 1.5 following 12 months of treatment.

RESULTS

Following 12 months of treatment, 104 (21%) of 501 biologic-naive patients had no response to treatment, and 397 (79%) had a clinical response. Among the latter, 97 (24%) fulfilled the study criteria of clinical remission, corresponding to 19% of the entire population. Remission was predicted by shorter duration of disease and lower BMI in the entire population of patients treated with biologic therapy.

INTERPRETATION

Clinical response was achieved in most adult patients initiating biologic therapy, and clinical remission was observed in 19% of the patients following 12 months of treatment. Further studies are required to assess the long-term outcome of achieving clinical remission with biologic therapy.

The effect of vitamin K2 supplementation on coronary artery disease in a randomized multicenter trial

Background

Coronary artery calcification (CAC) and especially progression in CAC is a strong predictor of acute myocardial infarction (AMI) and cardiovascular mortality [1]. Observational studies suggest a protective role of vitamin K2 in the development of CAC [2]. Measurement of CAC score in Agatston Units (AU) is common practice, while novel software as AutoPlaque introduces new opportunities to measure coronary plaques [3].

Purpose

The aim of this double-blinded randomized multicenter trial is to investigate if vitamin K2 supplementation can reduce the progression of CAC in a population without known coronary disease.

Methods

AVADEC is a multicenter trial investigating 389 participants randomized to vitamin K2 (720 μg/day) and vitamin D (25 μg/day) versus placebo with a 2-year follow-up from 2018–2019 [4]. The primary endpoint of AVADEC is change in aortic valve calcification. In this substudy, we examined the progression of CAC in participants with no prior coronary disease (no myocardial infarction and/or revascularization) at baseline. Secondary, the change in CAC was evaluated in two prespecified subgroups (low-risk: CAC score <400 AU and high-risk: CAC ≥400 AU at baseline). Non-contrast CT-scans were performed at baseline, 12 and 24 months of follow-up. Contrast CT-scans were performed at baseline and 24 months. CAC score was measured with established software and expressed in Agatston Units (AU). On contrast CT-scans, quantitative coronary plaque composition evaluations were performed by using Autoplaque. Moreover, events (AMI, revascularization and all cause death) were assessed.

Results

304 participants (male, mean age 71 years) with no prior coronary disease were identified. The intervention and placebo groups were similar in all traditional cardiovascular risk factors except familial predisposition for cardiovascular disease (14.4% vs. 6.7%, p=0.046). We found progression of CAC in both the intervention and placebo group from baseline to 24 month follow-up (203 AU vs. 254 AU, p=0.089) (Figure 1). The patients with CAC score <400 AU at baseline were equal in progression (77 AU vs. 81 AU, p=0.846). In patients with CAC score ≥400, the progression of CAC was significantly lower in the intervention group (288 AU vs. 380 AU, p=0.047). Yet, preliminary analyses of contrast CT-scans in 180 participants showed no difference in the progression of non-calcified plaque volume (10 mm3 vs. 37 mm3, p=0.276). In addition, the number of events was significantly lower in participants receiving vitamin K2 and D (1.9% vs. 6.7%, p=0.048).

Conclusion

Patients with no prior coronary disease randomized to vitamin K2 supplementation had a non-significant reduction in CAC development over a 2-year follow-up period. High-risk patients with CAC ≥400 AU had a significantly lower progression of CAC. Additionally, vitamin K2 supplementation significantly reduced the risk of AMI, revascularization and all-cause death.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Danish Cardiovascular Academy (2/3) and the Region of Southern Denmark (1/3).

Albumin-corrected Zn and available free Zn-binding capacity as indicators of Zn status - potential for clinical implementation

We have established and describe two measurement procedures to diagnose possible zinc (Zn) deficiency; albumin-corrected Zn concentration and available free Zn-binding capacity. Reference intervals for both biomarkers were established in healthy adults from the Danish population. The clinical usefulness of the measurement procedures was investigated in patients with cirrhosis and in patients given parenteral nutrition due to short bowel syndrome. The results of both methods indicate that there is a risk of overdiagnosing Zn deficiency based on low plasma Zn concentrations. Needless Zn supplementation may thus be avoided by using the albumin-corrected Zn concentration or available free Zn-binding capacity.

Global Variability in Administrative Approval Prescription Criteria for Biologic Therapy in Severe Asthma

BACKGROUND

Regulatory bodies have approved five biologics for severe asthma. However, regional differences in accessibility may limit the global potential for personalized medicine.

OBJECTIVE

To compare global differences in ease of access to biologics.

METHODS

In April 2021, national prescription criteria for omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab were reviewed by severe asthma experts collaborating in the International Severe Asthma Registry. Outcomes (per country, per biologic) were (1) country-specific prescription criteria and (2) development of the Biologic Accessibility Score (BACS). The BACS composite score incorporates 10 prescription criteria, each with a maximum score of 10 points. Referenced to European Medicines Agency marketing authorization specifications, a higher score reflects easier access.

RESULTS

Biologic prescription criteria differed substantially across 28 countries from five continents. Blood eosinophil count thresholds (usually ≥300 cells/μL) and exacerbations were key requirements for anti-IgE/anti-IL-5/5R prescriptions in around 80% of licensed countries. Most countries (40% for dupilumab to 54% for mepolizumab) require two or more moderate or severe exacerbations, whereas numbers ranged from none to four. Moreover, 0% (for reslizumab) to 21% (for omalizumab) of countries required long-term oral corticosteroid use. The BACS highlighted marked between-country differences in ease of access. For omalizumab, mepolizumab, benralizumab, and dupilumab, only two, one, four, and seven countries, respectively, scored equal or higher than the European Medicines Agency reference BACS. For reslizumab, all countries scored lower.

CONCLUSIONS

Although some differences were expected in country-specific biologic prescription criteria and ease of access, the substantial differences found in the current study present a challenge to implementing precision medicine across the world.

Real World Biologic Use and Switch Patterns in Severe Asthma: Data from the International Severe Asthma Registry and the US CHRONICLE Study

Introduction

International registries provide opportunities to describe use of biologics for treating severe asthma in current clinical practice. Our aims were to describe real-life global patterns of biologic use (continuation, switches, and discontinuations) for severe asthma, elucidate reasons underlying these patterns, and examine associated patient-level factors.

Methods

This was a historical cohort study including adults with severe asthma enrolled into the International Severe Asthma Registry (ISAR; http://isaregistries.org, 2015–2020) or the CHRONICLE Study (2018–2020) and treated with a biologic. Eleven countries were included (Bulgaria, Canada, Denmark, Greece, Italy, Japan, Kuwait, South Korea, Spain, UK, and USA). Biologic utilization patterns were defined: 1) continuing initial biologic; 2) stopping biologic treatment; or 3) switching to another biologic. Reasons for discontinuation/switching were recorded and comparisons drawn between groups.

Results

A total of 3531 patients were included. Omalizumab was the most common initial biologic in 2015 (88.2%) and benralizumab in 2019 (29.6%). Most patients (79%; 2791/3531) continued their first biologic; 10.2% (356/3531) stopped; 10.8% (384/3531) switched. The most frequent first switch was from omalizumab to an anti–IL-5/5R (49.6%; 187/377). The most common subsequent switch was from one anti–IL-5/5R to another (44.4%; 20/45). Insufficient efficacy and/or adverse effects were the most frequent reasons for stopping/switching. Patients who stopped/switched were more likely to have a higher baseline blood eosinophil count and exacerbation rate, lower lung function, and greater health care resource utilization.

Conclusion

The description of real-life patterns of continuing, stopping, or switching biologics enhances our understanding of global biologic use. Prospective studies involving structured switching criteria could ascertain optimal strategies to identify patients who may benefit from switching.

The Danish severe asthma register: an electronic platform for severe asthma management and research

The evaluation and management of severe asthma patients require collection of comprehensive information, which is often a challenge in a busy outpatient clinic. The Danish Severe Asthma Register (DSAR) was designed as an electronic patient record form that captures operational clinical data and provides a clinical overview of the severe asthma patient. DSAR is a nationwide register; all patients in Denmark who are treated with biologics for severe asthma are included, and data are as a minimum entered at start of biological treatment, after four and 12 months of treatment, and hereafter annually. Currently, there are data from 621 treatment courses with biologics included in DSAR, with 71% of patients treated with anti-IL-5 drugs and 29% with an anti-IgE drug. Patients enter Patient Reported Outcome Measures electronically on tablets when they arrive in the outpatient clinic and their answers are immediately available to the clinician during the consultation. Nurses and doctors enter clinical data into DSAR during the consultation. DSAR offers immediate access to well-presented longitudinal overview and automatically creates a journal output that can be copy-pasted into the hospital's existing health record form. DSAR is also currently expanding with an app, to be used for monitoring of home-treatment. In addition to serving as an electronic patient record form, DSAR will also provide opportunities to monitor the real-life efficacy of biological treatment for severe asthma in Denmark, and it will be a valuable research platform that will aid in answering important research questions on severe asthma in the future.

456Risk of arterial calcification by conventional vitamin K antagonist treatment

Background

Vitamin K antagonists (VKA) are the most frequently prescribed oral anticoagulants worldwide although new oral anticoagulants (NOAC) have become an important alternative. VKA inhibits Vitamin K1 necessary to produce coagulation factors but also Vitamin K2, which is essential in the activation of matrix-Gla protein, thought to be a strong local inhibitor of arterial calcifications.

Purpose

The aim was to investigate, whether VKA treatment is associated with coronary artery calcification (CAC) in a population with no prior cardiovascular disease (CVD).

Methods

We collected data on cardiovascular risk factors and CAC scores from cardiac CT scans performed as part of clinical examinations (n=9,672) or research studies (n=14,166) in the period 2007–2017. Data on use of VKA and NOAC was obtained from the Danish National Health Service Prescription Database. The association between VKA treatment duration and categorized CAC score was investigated by ordered logistic regression while adjusting for covariates. The independent variables included in the model were: age, gender, smoking, body mass index (BMI), diabetes mellitus, hypertension, hypercholesterolemia and/or statin treatment, family history of CVD, estimated glomerular filtration rate, VKA treatment duration and NOAC treatment duration. The categorisation of CAC was: 0, 1–99, 100–399 and ≥400 AU, corresponding to no, mild, moderate and severe atherosclerotic plaque burden, respectively.

Results

The final study population consisted of 17,254 participants (median 67 years old, 75% males) with no prior CVD, of which 1,748 (10%) and 1,144 (7%) had been treated with VKA or NOAC, respectively. A longer duration of VKA treatment was associated with higher CAC categories (Figure). For each cumulative year of VKA treatment, the odds of being in a higher CAC category, i.e. having more severe atherosclerosis, increased (odds ratio (OR)=1.032, 95% CI 1.009–1.057). All traditional cardiovascular risk factors were also associated with CAC. In contrast, NOAC treatment duration was not associated with CAC category (OR=1.004, 95% CI 0.937–1.075). In a sensitivity analysis of patients without statin treatment (n=12,143), the association between VKA treatment and CAC category remained unchanged. There was no significant interaction between VKA treatment duration and age on CAC category.

Conclusion

Adjusted for cardiovascular risk factors, VKA treatment – in contrast to NOAC - is associated with more severe CAC. Additional studies are required to clarify the clinical importance of this association in terms of hard cardiovascular endpoints.

Acknowledgement/Funding

Novo Nordisk Foundation and Independent Research Fund Denmark

Baseline findings of the population-based, randomized, multifaceted Danish cardiovascular screening trial (DANCAVAS) of men aged 65–74 years

Background

The challenge of managing age-related diseases is increasing; routine checks by the general practitioner do not reduce cardiovascular mortality. The aim here was to reduce cardiovascular mortality by advanced population-based cardiovascular screening. The present article reports the organization of the study, the acceptability of the screening offer, and the relevance of multifaceted screening for prevention and management of cardiovascular disease.

Methods

Danish men aged 65–74 years were invited randomly (1 : 2) to a cardiovascular screening examination using low-dose non-contrast CT, ankle and brachial BP measurements, and blood tests.

Results

In all, 16 768 of 47 322 men aged 65–74 years were invited and 10 471 attended (uptake 62·4 per cent). Of these, 3481 (33·2 per cent) had a coronary artery calcium score above 400 units. Thoracic aortic aneurysm was diagnosed in the ascending aorta (diameter 45 mm or greater) in 468 men (4·5 per cent), in the arch (at least 40 mm) in 48 (0·5 per cent) and in the descending aorta (35 mm or more) in 233 (2·2 per cent). Abdominal aortic aneurysm (at least 30 mm) and iliac aneurysm (20 mm or greater) were diagnosed in 533 (5·1 per cent) and 239 (2·3 per cent) men respectively. Peripheral artery disease was diagnosed in 1147 men (11·0 per cent), potentially uncontrolled hypertension (at least 160/100 mmHg) in 835 (8·0 per cent), previously unknown atrial fibrillation confirmed by ECG in 50 (0·5 per cent), previously unknown diabetes mellitus in 180 (1·7 per cent) and isolated severe hyperlipidaemia in 48 men (0·5 per cent).

In all, 4387 men (41·9 per cent), excluding those with potentially uncontrolled hypertension, were referred for additional cardiovascular prevention. Of these, 3712 (35·5 per cent of all screened men, but 84·6 per cent of those referred) consented and were started on medication.

Conclusion

Multifaceted cardiovascular screening is feasible and may optimize cardiovascular disease prevention in men aged 65–74 years. Uptake is lower than in aortic aneurysm screening.

A role for collagen type IV in cardiovascular disease?

Over the past decade, studies have repeatedly found single-nucleotide polymorphisms located in the collagen ( COL) 4A1 and COL4A2 genes to be associated with cardiovascular disease (CVD), and the 13q34 locus harboring these genes is one of ~160 genome-wide significant risk loci for coronary artery disease. COL4A1 and COL4A2 encode the α₁- and α₂-chains of collagen type IV, a major component of basement membranes in various tissues including arteries. Despite the growing body of evidence indicating a role for collagen type IV in CVD, remarkably few studies have aimed to directly investigate such a role. The purpose of this review is to summarize the clinical reports linking 13q34 to coronary artery disease, atherosclerosis, and artery stiffening and to assemble the scattered pieces of evidence from experimental studies based on vascular cells and tissue collectively supporting a role for collagen type IV in atherosclerosis and other macrovascular disease conditions.

Insulin resistance in vascular endothelial cells promotes intestinal tumour formation

The risk of several cancers, including colorectal cancer, is increased in patients with obesity and type 2 diabetes, conditions characterized by hyperinsulinemia and insulin resistance. Because hyperinsulinemia itself is an independent risk factor for cancer development, we examined tissue-specific insulin action in intestinal tumor formation. In vitro, insulin increased proliferation of primary cultures of intestinal tumor epithelial cells from Apc^Min/+ mice by over 2-fold. Surprisingly, targeted deletion of insulin receptors in intestinal epithelial cells in Apc^Min/+ mice did not change intestinal tumor number or size distribution on either a low or high-fat diet. We therefore asked whether cells in the tumor stroma might explain the association between tumor formation and insulin resistance. To this end, we generated Apc^Min/+ mice with loss of insulin receptors in vascular endothelial cells. Strikingly, these mice had 42% more intestinal tumors than controls, no change in tumor angiogenesis, but increased expression of vascular cell adhesion molecule-1 (VCAM-1) in primary culture of tumor endothelial cells. Insulin decreased VCAM-1 expression and leukocyte adhesion in quiescent tumor endothelial cells with intact insulin receptors and partly prevented increases in VCAM-1 and leukocyte adhesion after treatment with tumor necrosis factor-α. Knockout of insulin receptors in endothelial cells also increased leukocyte adhesion in mesenteric venules and increased the frequency of neutrophils in tumors. We conclude that although insulin is mitogenic for intestinal tumor cells in vitro, its action on tumor cells in vivo is via signals from the tumor microenvironment. Insulin resistance in tumor endothelial cells produces an activated, proinflammatory state that promotes tumorigenesis. Improvement of endothelial dysfunction may reduce colorectal cancer risk in patients with obesity and type 2 diabetes.

The DanCavas Pilot Study of Multifaceted Screening for Subclinical Cardiovascular Disease in Men and Women Aged 65-74 Years

OBJECTIVE/BACKGROUND

This pilot study of a large population based randomised screening trial investigated feasibility, acceptability, and relevance (prevalence of clinical and subclinical cardiovascular disease [CVD] and proportion receiving insufficient prevention) of a multifaceted screening for CVD.

METHODS

In total, 2060 randomly selected Danish men and women aged 65-74 years were offered (i) low dose non-contrast computed tomography to detect coronary artery calcification (CAC) and aortic/iliac aneurysms; (ii) detection of atrial fibrillation (AF); (iii) brachial and ankle blood pressure measurements; and (iv) blood levels of cholesterol and hemoglobin A1c. Web based self booking and data management was used to reduce the administrative burden.

RESULTS

Attendance rates were 64.9% (n = 678) and 63.0% (n = 640) for men and women, respectively. In total, 39.7% received a recommendation for medical preventive actions. Prevalence of aneurysms was 12.4% (95% confidence interval [CI] 9.9-14.9) in men and 1.1% (95% CI 0.3-1.9) in women, respectively (p < .001). A CAC score > 400 was found in 37.8% of men and 11.3% of women (p < .001), along with a significant increase in median CAC score with age (p = .03). Peripheral arterial disease was more prevalent in men (18.8%, 95% CI 15.8-21.8) than in women (11.2%, 95% CI 8.7-13.6). No significant differences between the sexes were found with regard to newly discovered AF (men 1.3%, women 0.5%), potential hypertension (men 9.7%, women 11.5%), hypercholesterolemia (men 0.9%, women 1.1%) or diabetes mellitus (men 2.1%, women 1.3%).

CONCLUSION

Owing to the higher prevalence of severe conditions, such as aneurysms and CAC ≥ 400, screening for CVD seemed more prudent in men than women. The attendance rates were acceptable compared with other screening programs and the logistical structure of the screening program proved successful.

YKL-40 and genetic status of CHI3L1 in a large group of asthmatics

Background

Studies have shown a relationship between asthma, serum YKL-40, and the single nucleotide polymorphism (SNP) (−131 C/G, rs4950928) in the CHI3L1 gene that codes for YKL-40. However, the findings differ. We studied the relationship between clinical asthma phenotypes, serum YKL-40, and SNP (−131 C/G, rs4950928).

Methods

In this study, 1,137 patients with asthma, 415 with rhinitis only, and 275 non-asthmatic controls were included. Assessment included a clinical interview concerning the diagnosis of asthma, severity of asthma, and asthma treatment as well as clinical tests to assess asthma and rhinitis. Serum YKL-40 was measured, and genotyping for the SNP (−131 C/G) was conducted.

Results

No significant difference in the serum concentration of YKL-40 was found between patients with asthma, patients with rhinitis, and non-asthmatic controls; however, YKL-40 was increased in patients with severe asthma. No association was found between the SNP (−131 C/G rs4950982) and the risk of having asthma (odds ratio = 0.90, p=0.4). Higher levels of serum YKL-40 were found in all subjects when comparing CC genotype to CG and GG genotypes (45 µg/L vs. 32 µg/L and 19 µg/L, p<0.0001).

Conclusion

There was no association between polymorphisms of SNP (−131 C/G) and asthma. The highest serum YKL-40 concentrations were seen in severe asthmatics. Individuals with less severe asthma showed a smaller difference against controls, limiting its clinical usefulness. More research is needed to clarify the relationship between different asthma phenotypes, YKL-40, and CHI3L1.

Low-dose spironolactone reduces plasma fibulin-1 levels in patients with type 2 diabetes and resistant hypertension

Diabetic patients with hypertension are at particularly high risk of vascular damage and consequently cardiovascular and renal disease. Fibulin-1, an extracellular matrix glycoprotein, is increased in arterial tissue and plasma from individuals with type 2 diabetes. This study aimed to evaluate whether antihypertensive treatment with spironolactone changes plasma fibulin-1 levels. In a multicenter, double-blind, randomized, placebo-controlled study, 119 patients with type 2 diabetes and resistant hypertension were included. A dose of spironolactone 25 mg or matching placebo was added to previous treatment at randomization. Blood pressure (BP) and plasma fibulin-1 were measured at baseline and at 16 weeks follow-up. Overall, 112 patients completed the study. All measures of BP were reduced in the spironolactone group at follow-up. Plasma fibulin-1 was significantly reduced after spironolactone treatment (P=0.009), but increased after placebo (P=0.017). Baseline plasma fibulin-1 correlated with BP and estimated glomerular filtration rate. Increased levels of plasma fibulin-1 (P=0.004) were observed in diabetic participants reporting erectile dysfunction as compared with participants who did not. Treatment with low-dose spironolactone reduced plasma fibulin-1 levels in patients with type 2 diabetes and resistant hypertension. This supports the hypothesis that the antihypertensive effect of the mineralocorticoid receptor blocker in part may be due to regression of vascular remodeling.

Plasma osteoprotegerin is associated with testosterone levels but unaffected by pioglitazone treatment in patients with polycystic ovary syndrome

OBJECTIVE

Increased osteoprotegerin (OPG) levels are associated with increased cardiovascular risk and decreased bone resorption. Pioglitazone treatment reduces the inflammatory state but may decrease bone mineral density (BMD). OPG levels during pioglitazone treatment have not previously been evaluated in polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

Plasma OPG levels were measured in 30 PCOS patients before and after randomized treatment with 30 mg pioglitazone/placebo for 16 weeks. Fourteen age- and body mass index-matched healthy women were included as controls. Clinical and hormonal evaluations and whole body dual-energy X-ray absorptiometry scans were performed in all participants.

RESULTS

OPG levels were comparable in PCOS patients [12.0 (10.5-14.6) ng/ml] and controls [12.9 (11.7-14.9) ng/ml]. In PCOS patients (no.=30), OPG levels were positively associated with testosterone (r=0.43), PRL (r=0.47), Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (r=0.43), and hip BMD, whereas inverse associations were found between OPG levels and triglyceride (r=-0.49) and free fatty acid levels during euglycemic clamps (r=-0.38), all p<0.05. Pioglitazone treatment significantly decreased inflammatory markers, insulin sensitivity, and BMD without affecting OPG levels.

CONCLUSIONS

OPG levels were comparable in PCOS patients and controls and unchanged during insulin sensitizing treatment with pioglitazone. OPG levels were associated with BMD in PCOS. Future studies need to evaluate OPG as a marker of cardiovascular disease in PCOS.

Persistent organic pollutants and methoxylated polybrominated diphenyl ethers in different tissues of white-tailed eagles (Haliaeetus albicilla) from West Greenland

We investigated polychlorinated biphenyls (PCBs), organochlorine pesticides (e.g. dichlorodiphenyltrichloroethane (DDT)), polybrominated diphenyl ethers (PBDEs) and methoxylated PBDEs (MeO-PBDEs), in six matrices (muscle, liver, kidney, adipose, blood, preen oil) of 17 white-tailed eagles from West Greenland sampled between 1997 and 2009. High inter-individual variation in contamination was found (PCBs: 0.49-1500 μg/g lipid weight (lw), DDTs: 0.23-910 μg/g lw, PBDEs: 0.01-24 μg/g lw, MeO-PBDEs: 0.001-0.59 μg/g lw), mostly due to age-related differences and not to temporal trends. One adult female (age > 5 years) displayed PCB levels up to 1500 μg/g lw in liver, which is the highest concentration ever reported in Arctic wildlife. Muscle generally contained the highest median levels, while adipose tissue displayed the lowest median levels on a lipid basis. No significant differences were found among tissues for MeO-PBDEs. Remarkably, we found distinct correlations (0.62 ≤ r ≤ 0.98; <0.0001 ≤ p ≤ 0.17) between levels of MeO-PBDEs and PBDEs, suggesting similar bioaccumulation pathways of PBDEs and MeO-PBDEs in white-tailed eagles.

Osteoprotegerin levels decrease during testosterone therapy in aging men and are associated with changed distribution of regional fat

The cardiovascular effects of testosterone treatment are debated. Osteoprotegerin (OPG) is an independent marker of cardiovascular risk. We investigated the effect of testosterone therapy on OPG levels in aging men with low normal bioavailable testosterone levels. A randomized, double-blinded, placebo-controlled study of 6 months testosterone therapy (gel) in 38 men aged 60-78 years with bioavailable testosterone <7.3 nmol/l and waist circumference >94 cm was performed. Clinical evaluation, OPG, and C-reactive protein (CRP) measurements were carried out. Lean body mass (LBM), total fat mass, and bone mineral density (BMD) were established by dual X-ray absorptiometry. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured by magnetic resonance imaging. Power calculation was based on an increase in LBM during testosterone therapy and responders were defined as testosterone treated patients with increased LBM (Δ LBM positive), n=14. Data are presented as median (interquartile range). Testosterone therapy decreased total fat mass and SAT, whereas VAT was unchanged (n=38). OPG levels decreased during testosterone therapy (from 2.0 (1.9-2.5) to 1.9 (1.6-2.2) ng/ml, p<0.05 vs. placebo), whereas CRP levels were unchanged (n=38). In responders to testosterone therapy (n=14), ΔOPG levels were inversely associated with ΔSAT (r= - 0.60, p=0.03) and positively associated with ΔVAT (r=0.56, p=0.04). OPG levels decreased during testosterone therapy suggesting decreased cardiovascular risk. Decreased OPG levels were associated with changes in regional fat distribution and future studies are needed to further evaluate the association between OPG and regional fat mass distribution.

The relationship between HbA1c and fasting plasma glucose in patients with increased plasma liver enzyme measurements

BACKGROUND

HbA(1c) is currently being introduced for diagnostic purpose in diabetes. Previous studies have, however, indicated that patients with liver disease have false low HbA(1c) levels. We therefore investigated the correlation between HbA(1c) and plasma glucose in patients with different levels of increased liver enzyme concentrations.

METHODS

Data from 10,065 patients with simultaneous measurement of HbA(1c), venous fasting plasma glucose, alanine aminotransferase and γ-glutamyl transferase were extracted from our laboratory database. Correlations were investigated in four patient groups divided according to their liver enzyme concentrations.

RESULTS

The correlation between HbA(1c) and plasma glucose was high in all groups, with r = 0.77 for men and r = 0.78 for women (P < 0.001), a correlation confirmed with multiple regression analysis (P < 0.001). However, interaction analysis revealed that linear regression lines were significantly different for men and women, with increase of both liver enzyme measurements and also, for women, with increased alanine aminotransferase. When compared with biological variation for HbA(1c), only men with increased measurements of both liver enzymes had a clinically important decrease in HbA(1c).

CONCLUSIONS

Increased liver enzyme concentrations do not bias the correlation between HbA(1c) and fasting plasma glucose. However, men with low plasma glucose and increased concentrations of both liver enzymes do have a slightly decreased HbA(1c) and, if the clinical suspicion is strong enough, one should consider supplement testing.

NT-proBNP is associated with fibulin-1 in Africans: the SAfrEIC study

OBJECTIVES

The N-terminal prohormone B-type natriuretic peptide (NT-proBNP) is involved in the regulation of volume load and secreted when systemic cardiac overload occurs. Fibulin-1 on the other hand is a component of many extracellular matrix proteins including those present in atherosclerotic lesions, expressed in elastin-containing fibres of blood vessels, and also in the heart. Due to an alarming prevalence of hypertensive heart disease in black South Africans, we investigated the associations of NT-proBNP with fibulin-1 and markers of arterial stiffness in Africans and Caucasians.

METHODS

We included 231 Africans and 238 Caucasians from South Africa aged 22-77 years. Serum NT-proBNP and fibulin-1 levels were determined, and arterial compliance and pulse wave velocity were measured.

RESULTS

Africans had significantly higher blood pressure and NT-proBNP levels than Caucasians and African men had higher fibulin-1 levels than Caucasian men. In single regression analysis, NT-proBNP was significantly associated with fibulin-1 in African men and Caucasian women. NT-proBNP correlated negatively with arterial compliance in all groups except Caucasian women. After partial adjustments, the association between NT-proBNP and fibulin-1 strengthened in African men only. After full adjustment in multiple regression analysis, the association of NT-proBNP with fibulin-1 was confirmed in African men (R(2)=0.41; β=0.26; p<0.01) and also in younger women (R(2)=0.34; β=0.251; p=0.012).

CONCLUSIONS

Only Africans indicated a significant independent association between NT-proBNP and fibulin-1, suggesting that cardiovascular alterations are already present in this relatively young African population as opposed to Caucasians.

Levels of Circulating MMCN-151, a Degradation Product of Mimecan, Reflect Pathological Extracellular Matrix Remodeling in Apolipoprotein E Knockout Mice

AIM

Arterial extracellular matrix (ECM) remodeling by matrix metalloproteinases (MMPs) is one of the major hallmarks of atherosclerosis. Mimecan, also known as osteoglycin has been implicated in the integrity of the ECM. This study assessed the validity of an enzyme-linked immunosorbent assay (ELISA) developed to measure a specific MMP12-derived fragment of mimecan, MMCN-151, in apolipoprotein-E knockout (ApoE-KO) mice.

METHODS AND RESULTS

A mouse monoclonal antibody raised against MMCN-151 was used to develop a competitive ELISA. The assay was validated using samples from 20 ApoE-KO and 20 wild type [C57 BL/6] male mice fed a normal or high-fat diet (HFD) for up to 20 weeks. The technical reliability of the assay was established with intra-assay variability <2% and inter-assay variability <10%. The lowest limit of quantification of MMCN-151 was 0.5 ng/ml. ApoE-KO mice fed a HFD for 20 weeks had four-fold increased circulating levels of MMCN-151 compared to baseline, whereas MMCN-151 levels in control mice on HFD increased two-fold compared with baseline. After 10 weeks of a HFD, a significant difference in MMCN-151 levels was observed between ApoE-KO and control mice (P = 0.005) and became more significant at 20 weeks (P = 0.002).

CONCLUSIONS

The newly developed assay is a reliable detector of MMCN-151 levels which ultimately may be useful indicators of arterial remodeling in patients affected by atherosclerotic disease.

A novel assay for extracellular matrix remodeling associated with liver fibrosis: An enzyme-linked immunosorbent assay (ELISA) for a MMP-9 proteolytically revealed neo-epitope of type III collagen

OBJECTIVES

Accumulation of extracellular matrix (ECM) components and increased matrix-metalloprotease (MMPs) activity are hallmarks of fibrosis. We developed an ELISA for quantification of MMP-9 derived collagen type III (CO3) degradation.

DESIGN AND METHODS

A monoclonal antibody targeting a specific MMP-9 cleaved fragment of CO3 was used for development of a competitive ELISA. The assay was investigated in serum and tissues from bile duct ligated rats (BDL).

RESULTS

The ELISA showed no cross-reaction with either intact CO3, or other collagens. The intra- and inter-assay CV were below 10%. Liver fibrosis was demonstrated in BDL animals by semi quantitative scoring (P<0.0001). Serum levels of CO3-610 increased 2.5 fold in BDL animals (P<0.001). The CO3-610 levels were 5 fold higher in ex vivo cultures of fibrotic livers compared to controls (P<0.001).

CONCLUSION

We have developed a novel ELISA for measuring a specific fragment CO3 generated by MMP-9 important in pathogenesis of liver fibrosis.

Plasma osteoprotegerin concentrations in peripheral sensory neuropathy in Type 1 and Type 2 diabetic patients

AIMS

Osteoprotegerin (OPG) has been linked to different diabetes complications, including cardiovascular disease, and new findings have indicated a specific role in diabetic peripheral neuropathy, but the exact mechanism is unknown. To investigate a possible association between OPG and diabetic peripheral sensory neuropathy, we therefore analysed plasma OPG in Type 1 and Type 2 diabetic patients with and without peripheral neuropathy.

SUBJECTS AND METHODS

Two hundred Type 1 diabetes mellitus (T1DM) patients and 305 Type 2 diabetes mellitus (T2DM) patients participated in the study. Plasma OPG was measured with a sandwich immunoassay. Peripheral neuropathy was assessed by the Semmes-Weinstein monofilament test.

RESULTS

In T2DM, plasma OPG concentrations were significantly higher in the peripheral neuropathy group (P < 0.001). Furthermore, there was a significant relationship between the presence of neuropathy in T2DM and plasma OPG levels on logistic regression (P = 0.006). However, when investigated in a full multiple regression model including other long-term diabetes complications, the association became insignificant (P = 0.092). In T1DM, the difference in plasma OPG between groups did not reach significance (P = 0.066). However, plasma OPG significantly correlated to peripheral neuropathy in this group also (P = 0.022), although this correlation was not significant in a multiple linear regression model (P = 0.051).

CONCLUSION

Plasma OPG levels are related to peripheral neuropathy in both Type 1 and Type 2 diabetes, although with the strongest relationship in T2DM. Before understanding the significance of this, the pathological mechanism involved and, speculatively, a possible use of plasma OPG as a peripheral sensory neuropathy marker, a larger prospective study is needed.

Medial arterial calcification in diabetes and its relationship to neuropathy

Calcification of the media of arterial walls is common in diabetes and is particularly associated with distal symmetrical neuropathy. Arterial calcification also complicates chronic kidney disease and is an independent risk factor for cardiovascular and all-cause mortality. The term calcification is not strictly accurate because the morphological changes incorporate those of new bone formation, i.e. ossification. The processes are complex, but are closely related to those involved in bone homeostasis, and it is relevant that calcification of the arterial wall and osteopenia often co-exist. One particular factor linked to the development of arterial calcification is distal symmetrical neuropathy; indeed, it has been suggested that neuropathy explains the distal distribution of arterial calcification in diabetes. It has also been suggested that the link with neuropathy results from loss of neuropeptides, such as calcitonin gene-related peptide, which are inherently protective. The association between distal symmetrical neuropathy and calcification of the arterial wall highlights the fact that neuropathy may be an independent risk factor for cardiovascular mortality.

Plasma osteoprotegerin levels predict cardiovascular and all-cause mortality and deterioration of kidney function in type 1 diabetic patients with nephropathy

AIMS/HYPOTHESIS

The bone-related peptide osteoprotegerin is produced by vascular cells and is involved in the process of vascular calcification. The aim of this study was to investigate the predictive value of plasma levels of osteoprotegerin in relation to mortality, cardiovascular events and deterioration in kidney function in patients with type 1 diabetes.

METHODS

This prospective observational follow-up study included 397 type 1 diabetic patients with overt diabetic nephropathy (243 men; age [mean+/-SD] 42.1 +/- 10.6 years, duration of diabetes 28.3 +/- 9.9 years, GFR 67 +/- 28 ml min(-1) 1.73 m(2)) and a group of 176 patients with longstanding type 1 diabetes and persistent normoalbuminuria (105 men; age 42.6 +/- 9.7 years, duration of diabetes 27.6 +/- 8.3 years).

RESULTS

The median (range) follow-up period was 11.3 (0.0-12.9) years. Among patients with diabetic nephropathy, individuals with high osteoprotegerin levels (fourth quartile) had significantly higher all-cause mortality than patients with low levels (first quartile) (covariate-adjusted hazard ratio [HR] 3.00 [1.24-7.27]). High osteoprotegerin levels also predicted cardiovascular mortality (covariate-adjusted HR 4.88 [1.57-15.14]). Furthermore, patients with high osteoprotegerin levels had significantly higher risk of progression to end-stage renal disease than patients with low levels (covariate-adjusted HR 4.32 [1.45-12.87]). In addition, patients with high levels of plasma osteoprotegerin had an elevated rate of decline in GFR.

CONCLUSIONS/INTERPRETATION

High levels of osteoprotegerin predict all-cause and cardiovascular mortality in patients with diabetic nephropathy. Furthermore, high levels of osteoprotegerin predict deterioration of kidney function towards end-stage renal disease.

Plasma concentrations of osteoprotegerin during normo- and hyperglycaemic clamping

OBJECTIVE

Plasma levels of osteoprotegerin (OPG) are elevated in subjects with diabetes as well as in non-diabetic subjects with cardiovascular disease. In previous studies a positive correlation was found between plasma levels of OPG and markers of glycaemic control in diabetic subjects. The aim of the present study was to examine the effect of acute hyperglycaemia on plasma levels of OPG in non-diabetic subjects.

MATERIAL AND METHODS

Nine healthy, lean, male subjects were examined in a randomized, blinded, cross-over study design during hyperglycaemic (plasma glucose = 15 mmol/L, study H) as well as during euglycaemic (plasma glucose = 5 mmol/L, study E) conditions. Blood samples were collected at baseline and at t=240 min.

RESULTS

Plasma OPG decreased slightly during study H (1.26+/-0.39 versus 1.19+/-0.35 ng/mL, p<0.05), whereas the level did not change significantly during study E (1.40+/-0.46 ng/mL versus 1.57+/-0.50 ng/mL, NS). The decrease in plasma OPG during hyperglycaemia did not correlate with the change in plasma glucose but correlated significantly with changes in serum insulin (r=-0.70, p=0.038).

CONCLUSIONS

Acute hyperglycaemia does not seem to increase plasma levels of OPG in non-diabetic subjects, whereas hyperinsulinaemia may suppress plasma levels of OPG. This finding indicates that the elevated plasma levels of OPG observed in diabetic subjects with poor metabolic control cannot be ascribed to hyperglycaemia per se.

Internet-based monitoring of asthma: a long-term, randomized clinical study of 300 asthmatic subjects

BACKGROUND

Experience from other fields of internal medicine shows that Internet-based technology can be used to monitor various diseases. The new technology handles complex calculation programs easily, and it is a unique way of communicating. These advantages might be used in optimizing the treatment for asthmatic subjects because undertreatment is a common problem found in European asthmatic subjects.

OBJECTIVE

We sought to investigate the outcome of monitoring and treatment using a physician-managed online interactive asthma monitoring tool and to assess whether the outcome differs from that of monitoring and treatment in an outpatient respiratory clinic or in primary care.

METHODS

Three hundred asthmatic subjects were randomized to 3 parallel groups in a 6-month prospective study: (1) Internet-based monitoring (n = 100); (2) specialist monitoring (n = 100); and (3) general practitioner (GP) monitoring (n = 100). All the patients were examined on entry into the study and after 6 months of treatment.

RESULTS

The treatment and monitoring with the Internet-based management tool lead to significantly better improvement in the Internet group than in the other 2 groups regarding asthma symptoms (Internet vs specialist: odds ratio of 2.64, P = .002; Internet vs GP: odds ratio of 3.26; P < .001), quality of life (Internet vs specialist: odds ratio of 2.21, P = .03; Internet vs GP: odds ratio of 2.10, P = .04), lung function (Internet vs specialist: odds ratio of 3.26, P = .002; Internet vs GP: odds ratio of 4.86, P < .001), and airway responsiveness (Internet vs GP: odds ratio of 3.06, P = .02).

CONCLUSION

When physicians and patients used an interactive Internet-based asthma monitoring tool, better asthma control was achieved.

Osteoprotegerin and diabetic macroangiopathy

Osteoprotegerin (OPG) is a bone-related protein that is also present in the vasculature. Recent data suggest that it may play a special role in arterial disease among patients with diabetes. Diabetic macroangiopathy is characterized by a series of diffuse, non-atherosclerotic alterations that hypothetically increase the vulnerability of the vessel wall to atherogenic processes. One prominent feature of the macroangiopathy is linear media calcifications, which have been found to impose a strong risk of future cardiovascular events in epidemiological studies. The mechanisms behind the development of calcifications are unknown, but may be related to the occurrence of diffuse matrix alterations in the arterial wall in diabetes. Interestingly, we have recently observed that the amounts of OPG are increased in the tunica media in arterial tissue from diabetic patients. OPG has been linked to vascular calcifications in immunohistochemical analysis of atherosclerotic tissue and experimental studies on OPG knockout mice. Thus, it is possible that increased arterial OPG concentrations reflect an osteogenic transformation of the vasculature in patients with diabetes as an aspect of diabetic macroangiopathy. This review will evaluate data about OPG in the vasculature and focus on a possible role of OPG in the arterial wall in diabetes.

Arterial osteoprotegerin: increased amounts in diabetes and modifiable synthesis from vascular smooth muscle cells by insulin and TNF-alpha

AIMS/HYPOTHESIS

Extracellular matrix modifications and linear medial calcifications are elements of diabetic macroangiopathy. We hypothesised that the bone-related protein osteoprotegerin (OPG) may occur in altered amounts in the arterial wall in diabetes, putatively associated with altered synthesis from vascular cells.

METHODS

The amount of OPG in the thoracic aorta, obtained at autopsy from 21 diabetic and 42 sex- and age-matched controls, was measured in tissue extracts by an ELISA. The production of OPG was estimated in conditioned media by an ELISA, and OPG mRNA was estimated by RT-PCR in vascular cells grown in vitro.

RESULTS

The content of OPG was increased in tunica media samples from diabetic individuals. No differences between diabetic and non-diabetic subjects were observed in tunica intima. Human vascular smooth muscle cells (HVSMCs) produced approximately 30 times more OPG than human umbilical vein endothelial cells. The OPG production into the medium decreased dose- and time-dependently after insulin treatment (maximal effect approximately 60% of control) in HVSMCs, whereas TNF-alpha supplement gave rise to increased OPG synthesis in a time- and dose-dependent manner (maximal effect approximately 200% of control). Similar effects on OPG mRNA expression were observed. Addition of growth hormone (10 ng/ml) or extra glucose (25 mmol/l) to the growth medium had no effect.

CONCLUSIONS/INTERPRETATION

Increased OPG concentrations in the arterial wall in diabetes may be part of generalised matrix alterations, putatively related to the development of vascular calcifications. Altered arterial OPG content may be a consequence of the effects of hormones and cytokines, like insulin and TNF-alpha.

Growth hormone receptor antagonist administration inhibits growth of human colorectal carcinoma in nude mice

Increasing evidence has accumulated in support of the hypothesis that growth hormone (GH) and insulin-like growth factors (IGFs) play a role in carcinogenesis. In order to test this hypothesis, female nude mice were xenografted with two different human colorectal cancer cell lines (COLO 205 and HT-29) and randomized to receive placebo or a GH receptor antagonist (GHRA) (B2036-PEG) every second day for 16 days. The tumour volume was measured in each animal throughout the study and by the end of the experiment the tumour weights were recorded. After 16 days of therapy in nude mice with the COLO 205 colorectal cancer, GHRA treatment caused a 39% reduction in tumour volume (p < 0.02) and a 44% reduction in tumour weight (p < 0.01). GHRA treatment equally reduced circulating IGF-I and IGFBP-3 levels, while apoptosis was increased in the treatment group. Expression of IGF-I, IGF-II and the corresponding receptors in COLO 205 tumours was also decreased by the treatment. GHRA had no effect on the growth of the HT-29 colorectal cancer despite pronounced reduction in serum IGF-I. The present study thereby demonstrates a central role for the GH/IGF system in the pathogenesis of some colorectal cancers and suggests that specific GHR blockade may present a new concept in the treatment of colorectal cancer.

Expression of Leptin Receptor Isoforms and Effects of Leptin on the Proliferation and Hormonal Secretion in Human Pituitary Adenomas

OBJECTIVE

To pursue whether leptin regulates anterior pituitary cells, we studied the ex vivo expression of several isoforms of the leptin receptor (OB-R) as well as the in vitro effects of leptin administration in human pituitary adenomas.

METHODS

OB-R mRNA expression and in vitro response to leptin were studied in 39 pituitary macroadenomas.

RESULTS

All 4 OB-R subtypes were expressed in most adenomas. The expression was significantly more pronounced in GH-secreting adenomas as compared to non-functioning tumor cells (p < 0.05). Leptin administration in vitro did not significantly influence cell proliferation or the secretion of GH, FSH, LH or alpha-subunit.

CONCLUSIONS

(1) Several isoforms of the OB-R, including the signal transducing full-length receptor, are expressed in most human pituitary adenomas. (2) This expression ex vivo is not associated with significant effects of leptin in vitro.

Increased plasma concentrations of osteoprotegerin in type 2 diabetic patients with microvascular complications

OBJECTIVE

Osteoprotegerin (OPG) is a newly identified inhibitor of bone resorption. Recent studies indicate that OPG also acts as an important regulatory molecule in the vasculature. Plasma levels of OPG seem to be elevated in subjects with diabetes as well as in non-diabetic subjects with cardiovascular disease. The aim of the present study was to examine the association between plasma OPG levels and microvascular complications and glycemic control in patients with type 2 diabetes.

DESIGN AND METHODS

Four groups of 20 subjects in each, individually matched for age and gender, were included in the study: (i) subjects with normal glucose tolerance (NGT); (ii) subjects with impaired glucose tolerance (IGT); (iii) type 2 diabetic patients without retinopathy; and (iv) type 2 diabetic patients with diabetic maculopathy (DMa). Plasma concentration of OPG was measured in duplicate by a sandwich ELISA method. Furthermore, fundus photography, flourescein angiography, and measurements of urinary albumin excretion rate (RIA) were performed.

RESULTS

Plasma OPG was significantly higher in diabetic (iii+iv) than in NGT (i) subjects (3.04+/-0.15 vs 2.54+/-0.16 ng/ml, P<0.05). Plasma OPG was significantly higher in the DMa (iv) group than in the NGT (i) group (3.25+/-0.23 vs 2.54+/-0.16 ng/ml, P=0.01). Moreover, plasma OPG was significantly higher (3.61+/-0.36 ng/ml) in the group of diabetic subjects with both microalbuminuria and DMa (n=7) than in the NGT (i) (2.54+/-0.16 ng/ml, P<0.01), IGT (ii) (2.82+/-0.21 ng/ml, P<0.05), and no retinopathy (iii) groups (2.83+/-0.20 ng/ml, P<0.05).

CONCLUSIONS

We found increased levels of OPG in plasma from diabetic patients with microvascular complications. This finding indicates that OPG may be involved in the development of vascular dysfunction in diabetes [corrected].

Increased expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured endothelial cells exposed to serum from type 1 diabetic patients: no effects of high glucose concentrations

Activation of the arterial endothelium may play an important role in the development of an atherosclerosis-prone vascular wall in diabetes. The induction of the adhesion molecules VCAM-1 and E-selectin on activated endothelial cells is crucial in monocyte recruitment during the atherogenic process. In the present study, we investigated whether sera from type 1 diabetic patients and non-diabetic persons are capable of inducing expression of VCAM-1 and E-selectin in human endothelial cells cultured in vitro. First, it was found that the addition of serum from non-diabetics to the cultures resulted in expression of adhesion molecules above basal level and also increased the cellular response to the cytokine tumor necrosis factor-alpha (TNF-alpha), a strong inducer of both adhesion molecules. Moreover, it was found that, on average, sera from 17 diabetic males induced a higher expression of VCAM-1 in the endothelial cells after 6 h of incubation than samples from 20 non-diabetic age-matched males (p < 0.05). No difference between the diabetic and non-diabetic group was seen in the expression of E-selectin. Likewise, no differences were observed between the effects of the sera to induce TNF-alpha responsivity. A series of experiments showed that alterations in the glucose concentrations of the growth medium (5.5-13.5 mmol/L) did not change the cellular content of either VCAM-1 or E-selectin before and after TNF-alpha treatment. In conclusion, it has been shown that sera from diabetic patients contain component(s), capable of inducing VCAM-1 expression in endothelial cells independent of hyperglycemia. Augmented induction of endothelial VCAM-1 expression by circulating factor(s) may play a role in the development of atherosclerosis in diabetes.

A murine vascular endothelial growth factor antibody inhibits in vivo growth of human Caki-I renal adenocarcinoma

A number of studies have provided indirect evidence that angiogenesis is involved in tumour growth and metastasis formation of renal cell carcinoma (RCC). Nude mice bearing xenografts of human Caki-I RCC were treated i.p. for 3 weeks with a murine monoclonal antibody against vascular endothelial growth factor, VEGF (VEGF-ab). Tumour growth and mRNA expression of human and murine VEGF and murine VE-Cadherin in the tumours were measured. After 3 weeks of therapy, the tumour volume in the control nude mice was 548 +/- 98 mm3 compared to the tumours in the nude mice treated with VEGF-ab (122 +/- 24 mm3, p < 0.01). Treatment with VEGF-ab significantly reduced mRNA expression of murine VEGF-120 and murine VE-Cadherin (p < 0.05 and p < 0.01, respectively). The mRNA expression of human VEGF (hVEGF165, hVEGF189) and murine VEGF (mVEGF164) was unchanged due to antibody treatment. The mean percentage of apoptotic cells in tumours harvested from antibody-treated animals was significantly lower than in tumours from the control-treated animals (p < 0.02). These findings demonstrate for the first time that VEGF-ab significantly inhibit the growth of Caki-1 RCC in vivo.

E-selectin-inducing activity in plasma from type 2 diabetic patients with maculopathy

Diabetic maculopathy (DMa) is a leading cause of visual loss in the western world. We examined whether plasma from type 2 diabetic patients with DMa contains factor(s) capable of inducing expression of the adhesion molecules E-selectin and VCAM-1 or cellular proliferation in cultured endothelial cells. Four gender-, age-, and duration (diabetes groups)-matched groups of 20 subjects each participated: 1) subjects with normal glucose tolerance (NGT), 2) subjects with impaired glucose tolerance (IGT), 3) type 2 diabetic patients without retinopathy, and 4) type 2 diabetic patients with DMa. Fasting plasma was added to in vitro-grown human umbilical vein endothelial cells for 6 h, after which E-selectin and VCAM-1 expression was measured. Proliferation was evaluated by thymidine incorporation. The individuals were characterized by measurement of 24-h ambulatory blood pressure, urinary albumin excretion rate, Hb A(1c), and blood lipids. Plasma from type 2 diabetic patients with DMa induced a significantly higher expression of E-selectin in endothelial cells than did plasma from subjects with NGT (259 +/- 23 x 10(3) vs. 198 +/- 19 x 10(3); arbitrary absorbance units; P < 0.05). There were no significant differences in plasma stimulatory effects on VCAM-1 expression or on thymidine incorporation between groups. These findings suggest that plasma from type 2 diabetic patients with DMa contains factor(s) capable of inducing the expression of E-selectin in endothelial cells. Enhanced expression of E-selectin may contribute to the development of DMa in type 2 diabetes.

Geographic variation of freeze-tolerance in the earthworm Dendrobaena octaedra

Freeze-tolerance and some of the underlying biochemical defence mechanisms in the earthworm Dendrobaena octaedra was investigated. Survival after slow cooling to -2 degrees C, -4 degrees C, or -6 degrees C was analysed in D. octaedra from three geographic regions representing large differences in winter temperature (Denmark, Finland and Greenland). A large variation in freeze-tolerance between the three populations of D. octaedra was found. Earthworms from the northern populations (Finland and Greenland) tolerated lower temperatures (-6 degrees C) than earthworms from the Danish population (poor survival at -4 degrees C and -2 degrees C). In the Finnish population, freezing led to the production of high concentrations of glucose, which reached values much higher than controls (94 mg g(-1) vs. 2 mg g(-1) dry weight). Other potential cryoprotectants were not elevated after freezing. The Danish and Greenlandic populations had substantially lower mean glucose levels after freezing than the Finnish population (about 15 mg g(-1)). Danish earthworms rapidly frozen did not accumulate glucose, and did not survive freezing at -2 degrees C. Danish earthworms exposed to osmotic stress in Ringer's solutions, containing different concentrations of glycerol, showed significantly elevated glucose levels, but did not survive rapid freezing. It was determined if freezing had an influence on the reproduction of the earthworms. After warming to summer temperatures (15 degrees C), survivors of freezing produced viable cocoons. In a field experiment it was tested if natural acclimatization during autumn and winter months had an effect on freeze-tolerance in the Danish population. There was a significant increase of post-freeze survival during this period. The results of the freezing experiments are discussed in relation to the general ecology of D. octaedra.

A new transcutaneous bilirubinometer, BiliCheck, used in the neonatal intensive care unit and the maternity ward

Transcutaneous bilirubin (TcB) was measured with a new bilirubinometer, BiliCheck, in 261 jaundiced infants in the neonatal intensive care unit (NICU) [gestational age (GA) 25-43 wk] (group 1) and in 227 healthy jaundiced term and near-term infants (GA 35-43 wk) (group 2). Imprecision of a single determination of TcB measured on the forehead [TcB(h)], expressed as 1 standard deviation, was 15-18 micromol l(-1). No statistically significant difference between intraoperator and interoperator imprecision was found. There was a good correlation between TcB(h) and total serum bilirubin (TSB) in both groups of infants, although TcB(h) was on average lower than TSB. In the NICU infants, TcB(h), other things being equal, was lower in males than in females, and decreased with increasing postnatal age, for the same TSB level. In the infants in both groups who had a GA > or = 35 wk, sick infants had a higher TcB(h) than healthy infants for the same TSB level. The differences were statistically significant, but small and of minor clinical significance. Blood haemoglobin concentration, GA and ethnic origin were not found to influence TcB(h), i.e. BiliCheck corrects sufficiently for these factors. In all 488 infants, TcB was measured at four different body sites. Measurements on the forehead and sternum [TcB(s)] correlated well with TSB, while measurements on the knee and foot correlated less well. In the NICU infants TcB(h) predicted TSB statistically significantly better than TcB(s), while in the healthy term and near-term infants TcB(h) and TcB(s) predicted TSB equally well. Therefore, the preferable body site for measurement of TcB under routine conditions is the forehead. By retrospective analysis of the data, a screening model is presented whereby TcB(h) can be used to screen infants who require phototherapy. We found that using screening limits for TcB(h), which are 70% of the currently used phototherapy limits for TSB, 80% of blood samples in healthy term and near-term infants, and 42% of NICU infants with GA > or = 32 wk, could be avoided.

CONCLUSION

BiliCheck is suitable for screening both NICU and healthy newborn infants with jaundice, with regard to the need for phototherapy. The authors recommend using a TcB(h) limit which is 70% of the currently recommended TSB limits for phototherapy, to decide whether TSB needs to be measured.

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.

Production of hyaluronan and chondroitin sulphate proteoglycans from human arterial smooth muscle--the effect of glucose, insulin, IGF-I or growth hormone

BACKGROUND

Although it is recognized that the extracellular matrix is important for cell proliferation, migration and metabolism of growth factors, the regulation of the synthesis of hyaluronan and chondroitin sulphate proteoglycan (CSPG) in the vessel wall is poorly understood.

OBJECTIVE

To examine the role of glucose, insulin, IGF-I and human growth hormone (hGH) on the accumulation of hyaluronan and CSPG using cultures of human aortic smooth muscle cells.

METHODS

The cultures were exposed for 36 h. The CSPG content in the incubation medium was measured by a combination of digestion with testicular hyaluronidase and precipitation of [35SO4(2-)]-labelled material with ethanol and trichloroacetic acid. Hyaluronan was estimated using a radiometric assay.

RESULTS

Glucose and insulin reduced the amount of synthesized hyaluronan (2P<0.01). Stimulation of synthesis was seen with hGH (2P<0.01), whereas no effect was observed with IGF-I. The production of CSPG was increased with glucose and hGH (2P<0.01), but showed no change with insulin.

CONCLUSIONS

The present data obtained with human arterial smooth muscle cells in vitro showed that glucose, insulin and hGH can influence the accumulation of hyaluronan and CSPG. These observations may be relevant for an understanding of diabetic macroangiopathy.

Laser-assisted microdissection of membrane-mounted paraffin sections for polymerase chain reaction analysis: identification of cell populations using immunohistochemistry and in situ hybridization

Laser microbeam microdissection (LMM) is an increasingly important method for obtaining pure cell samples for genetic and proteomic analysis. Immunohistochemistry (IHC) and in situ hybridization (ISH) are useful techniques for targeting specific cell populations for microdissection but are difficult to apply with the tissue support membranes often used during LMM. Using detection of cytokeratins and Epstein-Barr virus gene products in head and neck carcinoma as a model, we describe optimized protocols for membrane and section preparation and for low temperature antigen retrieval that allow IHC and ISH to be used reliably on membrane mounted paraffin tissue sections. Visualization of cellular targets was markedly improved by staining and this could be further improved using a variety of optical media before microdissection. Tissue fragments thus stained were suitable for subsequent polymerase chain reaction analysis of extracted DNA using standard techniques. These IHC and ISH procedures are generally applicable and will be useful for detecting a wide range of antigens and nucleic acids in paraffin sections in conjunction with LMM.

Induction of mucin and adhesion molecules in middle ear mucosa

We hypothesized that inflammation molecules induce the secretory hyperplasia characteristic of otitis media with effusion (OME). The purpose of the present study was to compare the location of inflammation molecules and mucin in the middle ear mucosa of both normal and OME ears. OME was created by bisection of the tensor veli palatini muscle in germ-free rabbits, and the development of middle ear effusion was confirmed by otomicroscopy and tympanometry. Ventilation tubes (VTs) were inserted in half of the ears. The animals were decapitated after 8 weeks, and serial sections of the middle ear mucosae were either periodic acid-Schiff (PAS)-stained or stained immunohistochemically for inflammation molecules or mucins. The length of stained epithelium was measured and related to the total epithelial length. There was a striking resemblance between mucin-type MUC5B- and PAS-positive epithelium and areas positive for the chemoattractant inflammation molecules intercellular adhesion molecule-1 (ICAM-1) and RANTES (reacted upon activation, normal T expressed and secreted). The percentages of ICAM-1- and PAS-stained epithelium were significantly higher in OME ears than in normal ears. OME ears treated with VTs also contained significantly more PAS-positive epithelium than normal ears, but less than OME ears. Based on the spatial and temporal coincidence between ICAM-1 and mucin, it is suggested that: (i) inflammation may initiate and maintain the hypersecretory state of the middle ear mucosa which is presumably responsible for the chronicity of OME; and (ii) that MUC5B is a major mucin component of OME effusions.

RANTES in otitis media with effusion: presence, role and correlation with cytokines and microbiology

Various inflammatory cells and cytokines have been identified in otitis media with effusion (OME). The presence of neutrophils has been linked to interleukin-8, but no chemotactic factor has as yet been identified for monocytes. The chemokine RANTES (Regulated upon Activation, Normal T Expressed and Secreted) attracts and activates primarily monocytes and may contribute to the pathogenesis of middle ear inflammation. We investigated the presence of RANTES by: 1) ELISA measurement in 114 middle ear effusions from children suffering from OME, 2) immunohistochemical localisation in experimental OME rabbit middle ear mucosa, and 3) expression in cultured rabbit middle ear epithelium in response to proinflammatory stimuli. RANTES was detectable in 94 (82%) of 114 effusions with a median concentration of 79.7 pg/mg total protein content. The concentration of RANTES was positively correlated with the endotoxin content. Immunohistochemically, RANTES was localized to the epithelial layer in experimental OME. In vitro, RANTES was expressed in middle ear epithelium in response to proinflammatory stimuli (TNF-alpha) in a dose-dependent manner. The expression of RANTES may explain the recruitment of monocytes in OME, possibly as a result of TNF-alpha-mediated endotoxin stimulation.

Expression of somatostatin receptors on human pituitary adenomas in vivo and ex vivo

The distribution and biologic activity of somatostatin receptor subtypes (SSTR) in pituitary adenomas is not clarified, especially regarding clinically non-functioning adenomas (NFPA). We therefore characterized SSTR in human pituitary adenomas by combining molecular biology and in vivo scintigraphy. Co-expression of gonadotropin-releasing hormone receptor (GnRH-R) mRNA was also assessed to see whether this feature was associated with adenoma subtype and SSTR status. Pituitary tumor biopsies were obtained during transsphenoidal adenomectomy from 21 patients (11 NFPA, 7 acromegalics, 2 prolactinomas, 1 Cushing's disease). Expression of mRNA encoding the 5 known SSTR subtypes and the GnRH-R was determined by RT-PCR. Twelve patients also underwent a pre-operative somatostatin receptor scintigraphy. Most adenomas (no.=18) expressed mRNA for more than one SSTR. SSTR2 mRNA was expressed in 18 cases, whereas SSTR4 was absent in all but one. SSTR3 was frequently expressed in NFPAs. Somatostatin receptor scintigraphy was positive in most cases, and with a significantly higher uptake index in GH-producing adenomas all of which expressed SSTR2 mRNA. The uptake index appeared to be related to receptor density rather than tumor volume. Expression of GnRH-R mRNA was found in both NFPAs and GH-producing adenomas and was not significantly associated with a particular SSTR subtype population.

IN CONCLUSION

1) the distribution of SSTR is not significantly different between NFPA and GH-producing adenomas; and 2) somatostatin receptor scintigraphy reveals a higher uptake in GH-producing adenomas which is not significantly related to either SSTR distribution or tumor volume.

How does endotoxin trigger inflammation in otitis media with effusion?

OBJECTIVES

The relationship among microorganisms, endotoxin, and inflammatory mediators in otitis media with effusion (OME) was examined.

STUDY DESIGN

Analysis of 152 middle ear effusions aspirated at the time of ventilation tube insertion from children with OME.

METHODS

Effusion samples were cultured for pathogenic bacteria The two primary cytokines, interleukin-1beta (IL1beta) and tumor necrosis factor (TNFalpha), and the adhesion molecules, intercellular and vascular adhesion molecule (ICAM-1 and VCAM-1), were quantified using the enzyme-linked immunosorbent assay (ELISA) technique. Endotoxin concentration was measured with a limulus amebocyte lysate assay, and total protein concentration was quantified using the Biorad microassay.

RESULTS

The cultures of pathogenic bacteria were positive in 33 of the 152 effusions (22%), which contained more endotoxin and more of the primary cytokines than the 119 culture-negative effusions. Endotoxin and the primary cytokines were positively correlated, both in the whole material and in the sterile effusions alone. The adhesion molecules were positively correlated with each other, but not with endotoxin or the primary cytokines.

CONCLUSIONS

We found a positive correlation between endotoxin and the primary cytokines TNFalpha and IL1beta in culture-positive OME effusions as well as in culture-negative ones, suggesting endotoxin-induced local production of TNFalpha and IL1beta in the middle ear. ICAM-1 and VCAM-1 were also present in the middle ear, but their concentrations were not directly correlated to endotoxin or the primary cytokines.

Influence of insertion/deletion polymorphism in the ACE-I gene on the progression of diabetic glomerulopathy in type 1 diabetic patients with microalbuminuria

OBJECTIVE

To investigate the influence of the insertion/deletion polymorphism of the ACE gene on the progression of early diabetic glomerulopathy in patients with and without antihypertensive treatment (AHT).

RESEARCH DESIGN AND METHODS

There were 30 microalbuminuric patients with >5 years of type 1 diabetes who had renal biopsies taken at baseline and after 26-48 months of follow-up. Of the 30 patients, 13 (4 with II genotype and 9 with ID and DD genotypes) were randomized to AHT (enalapril or metoprolol) during the study. The ACE genotype was determined by a polymerase chain reaction. Glomerular structural changes were measured by stereological methods.

RESULTS

Of the patients, 8 had the II genotype, 19 had ID genotype, and 3 had DD genotype. During the study, basement membrane thickness, matrix star volume, and the overall diabetic glomerulopathy index were increased in patients with ID and DD genotypes only (P < 0.001, P = 0.01, P < 0.001, respectively). Among those with ID and DD genotypes, progression of basement membrane thickening and diabetic glomerulopathy index were increased in those without AHT, as compared with the antihypertensive treated patients (P < 0.001, P = 0.02, respectively). In multivariate analysis, the ACE genotype had an independent influence on the progression of basement membrane thickening (P = 0.01), when AHT (P < 0.001) and the mean HbAlc during the study (P < 0.001) were also taken into account. ACE genotype tended to be independently associated with the diabetic glomerulopathy index (P = 0.05).

CONCLUSIONS

Microalbuminuric type 1 diabetic patients carrying the D-allele have an increased progression of diabetic glomerulopathy. Presence of this allele and no AHT seems to enhance this process. Larger studies are needed to confirm the clinical significance of our findings.

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.