Clinical Diagnostics of Fecal Calprotectin: a Comparative Study of Actim® Calprotectin and LIAISON® Calprotectin.

BACKGROUND: Fecal calprotectin (fCal) is an important surrogate biomarker of chronic inflammatory bowel disease (IBD): Crohn's disease and ulcerative colitis. Non-invasive, immunochromatographic rapid tests are excellent tools for the real-time monitoring of disease activity and reduce the need for invasive and costly colonoscopy procedures. METHODS: In this study the accuracy of fCal detection by the semi-quantitative Actim® Calprotectin and the quantitative automated LIAISON® Calprotectin assay was assessed on a panel of clinical stool samples. RESULTS: Of the 119 fecal samples tested, Actim® Calprotectin agreed on 94 samples (79.0%) with the reference test. Furthermore, of the positive samples detected with LIAISON® Calprotectin, 94.0% were interpreted as positive by Actim® Calprotectin. CONCLUSIONS: Actim® Calprotectin is a rapid test that can be utilized for the initial differentiation between negative and positive samples in an outpatient setting, thus helping to limit more laborious quantitative methods to positive samples.

Preliminary Report: Osteoarthritis and Rheumatoid Arthritis Synovial Fluid Increased Osteoclastogenesis In Vitro by Monocyte Differentiation Pathway Regulating Cytokines.

Background: Rheumatoid arthritis (RA) and osteoarthritis (OA) are common joint diseases associated with changes in local, as well as systemic bone structure and osteoclast function. We investigated how the different soluble inflammatory stimuli in these diseases can affect osteoclastogenesis and bone resorption in vitro. Methods. Human peripheral blood mononuclear cell-derived osteoclasts were cultured on bone slices with serum from treatment-naïve RA patients and healthy controls and with synovial fluid samples acquired from RA and OA patients. The concentrations of 29 different cytokines and related proteins, including RANKL and OPG, were analyzed in the fluids tested. Results: RA serum and synovial fluid increased both osteoclastogenesis and bone resorption. Osteoclastogenesis and activity increased more in the cultures containing OA than RA synovial fluid. The osteoclasts cultured in different culture media exhibited different phenotypes, especially the cells cultured with OA synovial fluid were generally larger and had more nuclei. A general increase in proinflammatory cytokines in RA synovial fluid and serum was found. Surprisingly, OA synovial fluid showed lower levels of osteoclastogenesis inhibiting cytokines, such as IL-4 and IL-10, than RA synovial fluid, which at least partly explains more pronounced osteoclastogenesis. No significant difference was found in RANKL or OPG levels. Conclusion: The proinflammatory stimulus in OA and RA drives the monocyte differentiation towards inflammatory osteoclastogenesis and altered osteoclast phenotype.

Fetal cardiovascular hemodynamics in type 1 diabetic pregnancies at near-term gestation.

INTRODUCTION: Poor glycemic control in maternal type 1 diabetes mellitus during pregnancy can affect fetal cardiac and placental function. However, studies concerning fetal central hemodynamics have revealed conflicting results. We hypothesized that in pregnancies complicated by maternal type 1 diabetes, fetal cardiovascular and placental hemodynamics are comparable to the control fetuses at near-term gestation. In addition, we investigated the relation between newborn serum biomarkers of cardiac function and fetal cardiovascular and placental hemodynamics. Furthermore, we studied whether maternal diabetes is associated with placental inflammation. MATERIAL AND METHODS: In this prospective case-control study, fetal central and peripheral hemodynamics were assessed by ultrasonography in 33 women with type 1 diabetes and in 67 controls with singleton pregnancies between 34+2 and 40+2 gestational weeks. Newborn umbilical cord serum was collected to analyze cardiac natriuretic peptides (atrial and B-type natriuretic peptides) and troponin T concentrations. Placental tissue samples were obtained for cytokine analyses. RESULTS: Fetal ventricular wall thicknesses were greater and weight-adjusted stroke volumes and cardiac outputs were lower in the type 1 diabetes group than in the control group. Pulsatility in the aortic isthmus and inferior vena cava blood flow velocity waveforms was greater in the type 1 diabetes group fetuses than in the controls. A positive correlation was found between branch pulmonary artery and aortic isthmus pulsatility index values. Umbilical artery pulsatility indices were comparable between the groups. Umbilical cord serum natriuretic peptide and troponin T concentrations were elevated in the type 1 diabetes fetuses. These cardiac biomarkers correlated significantly with cardiovascular hemodynamics. Placental cytokine levels were not different between the groups. CONCLUSIONS: In maternal type 1 diabetes pregnancies, fetal cardiovascular hemodynamics is impaired. Maternal type 1 diabetes does not seem to alter placental vascular impedance or induce placental inflammation.

Gestational hyperglycemia reprograms cardiac gene expression in rat offspring.

BackgroundRat fetuses with maternal pregestational hyperglycemia develop cardiac dysfunction, and their cardiac gene expression differs from that of healthy control fetuses near term. We hypothesized that cardiac gene expression and morphologic abnormalities of rat fetuses with maternal pregestational hyperglycemia become normal after birth.MethodsNine rats were preconceptually injected with streptozotocin to induce maternal hyperglycemia and nine rats served as controls. The hyperglycemia group comprised 82 mice and the control group 74 offspring fed by euglycemic dams. Hearts of the offspring were collected on postnatal days 0, 7, and 14, and processed for histologic and gene expression analyses.ResultsOn day 0, heart weight was increased, and expression of cardiac genes involved in contractility, growth, and metabolism was decreased in the hyperglycemia group. On day 7, although cardiomyocyte apoptosis was enhanced, most of the changes in gene expression had normalized in the hyperglycemia group. By day 14, the expression of genes important for myocardial growth, function, and metabolism was again abnormal in the hyperglycemia group.ConclusionMost cardiac gene expression abnormalities become transiently normal during the first week of life of offspring to hyperglycemic rats. However, by day 14, cardiac expressions of genes involved in growth, function, and metabolism are again abnormal in relation to control offspring.

Neoplastic extracellular matrix environment promotes cancer invasion in vitro.

The invasion of carcinoma cells is a crucial feature in carcinogenesis. The penetration efficiency not only depends on the cancer cells, but also on the composition of the tumor microenvironment. Our group has developed a 3D invasion assay based on human uterine leiomyoma tissue. Here we tested whether human, porcine, mouse or rat hearts as well as porcine tongue tissues could be similarly used to study carcinoma cell invasion in vitro. Three invasive human oral tongue squamous cell carcinoma (HSC-3, SCC-25 and SCC-15), melanoma (G-361) and ductal breast adenocarcinoma (MDA-MB-231) cell lines, and co-cultures of HSC-3 and carcinoma-associated or normal oral fibroblasts were assayed. Myoma tissue, both native and lyophilized, promoted invasion and growth of the cancer cells. However, the healthy heart or tongue matrices were unable to induce the invasion of any type of cancer cells tested. Moreover, when studied in more detail, small molecular weight fragments derived from heart tissue rinsing media inhibited HSC-3 horizontal migration. Proteome analysis of myoma rinsing media, on the other hand, revealed migration enhancing factors. These results highlight the important role of matrix composition for cancer invasion studies in vitro and further demonstrate the unique properties of human myoma organotypic model.

Characterization of apela, a novel endogenous ligand of apelin receptor, in the adult heart.

The G protein-coupled apelin receptor regulates important processes of the cardiovascular homeostasis, including cardiac development, cardiac contractility, and vascular tone. Most recently, a novel endogenous peptide ligand for the apelin receptor was identified in zebrafish, and it was named apela/elabela/toddler. The peptide was originally considered as an exclusively embryonic regulator, and so far its function in the adult organism remains elusive. We show here that apela is predominantly expressed in the non-cardiomyocyte fraction in the adult rodent heart. We also provide evidence that apela binds to apelin receptors in the heart. Using isolated adult rat hearts, we demonstrate, that just like the fellow receptor agonist apelin, apela increases cardiac contractility and induces coronary vasodilation already in the nanomolar level. The inotropic effect, as revealed by Western blot analysis, is accompanied by a significant increase in extracellular signal-regulated kinase (ERK) 1/2 phosphorylation. Pharmacological inhibition of ERK1/2 activation markedly attenuates the apela-induced inotropy. Analysis of samples from infarcted mouse hearts showed that expression of both apela and apelin receptor is induced in failing mouse hearts and correlate with left ventricular ejection fraction. Hence, we conclude that apela is present in the adult heart, is upregulated in post-infarction cardiac remodeling, and increases cardiac contractility in an ERK1/2-dependent manner.

Circulating N-terminal brain natriuretic peptide and cardiac function in response to acute systemic hypoxia in healthy humans.

BACKGROUND: As it remains unclear whether hypoxia of cardiomyocytes could trigger the release of brain natriuretic peptide (BNP) in humans, we investigated whether breathing normobaric hypoxic gas mixture increases the circulating NT-proBNP in healthy male subjects. METHODS: Ten healthy young men (age 29 ± 5 yrs, BMI 24.7 ± 2.8 kg/m2) breathed normobaric hypoxic gas mixture (11% O2/89% N2) for one hour. Venous blood samples were obtained immediately before, during, and 2 and 24 hours after hypoxic exposure. Cardiac function and flow velocity profile in the middle left anterior descending coronary artery (LAD) were measured by Doppler echocardiography. RESULTS: Arterial oxygen saturation decreased steadily from baseline value of 99 ± 1% after the initiation hypoxia challenge and reached steady-state level of 73 ± 6% within 20-30 minutes. Cardiac output increased from 6.0 ± 1.2 to 8.1 ± 1.6 L/min and ejection fraction from 67 ± 4% to 75 ± 6% (both p < 0.001). Peak diastolic flow velocity in the LAD increased from 0.16 ± 0.04 to 0.28 ± 0.07 m/s, while its diameter remained unchanged. In the whole study group, NT-proBNP was similar to baseline (60 ± 32 pmol/ml) at all time points. However, at 24 h, concentration of NT-proBNP was higher (34 ± 18%) in five subjects and lower (17 ± 17%), p = 0.002 between the groups) in five subjects than at baseline. CONCLUSION: In conclusion, there is no consistent increase in circulating NT-proBNP in response to breathing severely hypoxic normobaric gas mixture in healthy humans, a possible reason being that the oxygen flux to cardiac myocytes does not decrease because of increased coronary blood flow. However, the divergent individual responses as well as responses in different cardiac diseases warrant further investigations.

Depressive symptoms and cardiovascular burden-related mortality among the aged.

BACKGROUND: Depressive symptoms have been linked to increased cardiovascular mortality among the elderly. This study was aimed to test the independent and additive predictive value of depressive symptoms and B-type natriuretic peptide (BNP), a marker of direct cardiovascular stress and a strong predictor of mortality, together with traditional cardiovascular risk markers on total and cardiovascular mortalities in a general elderly population. METHODS: A total of 508 subjects aged 75 or older participated in the study. The prognostic capacity of depressive symptoms and BNP in regard to total and cardiovascular mortalities was assessed with Cox regression analyses. Depressive symptoms were handled as a dichotomous variable based on the Zung self-rated depression scale score with a cut-off point of 40. RESULTS: The median follow-up time was 84 months with an interquartile range of 36-99 months. Depressive symptoms reflected susceptibility to all-cause (HR 1·60; 95% CI 1·26-2·04) and cardiovascular mortalities (HR 1·81; 95% CI 1·30-2·52) only in univariable analyses. When cardiovascular illnesses and risk markers were taken into account, depressive symptoms lost their significance as an independent predictor of mortality. BNP as a continuous variable was a significant predictor of both all-cause (HR 1·44; 95% CI 1·22-1·69) and cardiovascular mortalities (HR 1·79; 95% CI 1·44-2·22) in fully adjusted models including depressive symptoms as a covariate. CONCLUSIONS: The prognostic capacity of depressive symptoms is closely linked to cardiovascular morbidity and has no independent power in an elderly general population. BNP remains a strong harbinger of death regardless of depressive symptoms status.

Hypoxia increases the release of salmon cardiac peptide (sCP) from the heart of rainbow trout (Oncorhynchus mykiss) under constant mechanical load in vitro.

Our aim was to study the effects of hypoxia on the release of salmon cardiac peptide (sCP) from an isolated heart ventricle of trout during a constant mechanical load. Trout heart ventricles were studied in vitro. The ventricle was placed in an organ bath at 12 °C in which a constant mechanical load could be imposed on the ventricle while buffer solution was circulating. Ventricles were field-stimulated with a supramaximal voltage pulse at a rate of about 0.3 s⁻¹. Samples of 1 ml were collected at an interval of 10 min for 200 min from the organ bath and assessed with a radioimmunoassay for sCP. After a control period of 20 min, ventricles were exposed to hypoxia produced with N2 gassing (n = 9) or to hypoxia with 20 mM BDM, a nonselective myosin ATPase inhibitor locking cross-bridges in a pre-power-stroke state inhibiting force production with normal electrical activity (n = 10). In this model and setup, hypoxia stimulated the release of sCP, but the interindividual variation in the response was large. At the end of hypoxia exposure, the concentration of sCP in the organ bath was about sixfold higher than at the start of the exposure (P < 0.05, one-way ANOVA for repeated measurements, followed by Dunnett's multiple comparison test). When BDM was introduced into the bath, the ventricle still secreted sCP but the hypoxic response was smaller than in the experiments without BDM. In the trout heart ventricle, there is a hypoxia-sensitive component in the release mechanism of sCP which is independent of contraction.

Maternal hyperglycemia leads to fetal cardiac hyperplasia and dysfunction in a rat model.

Accelerated fetal myocardial growth with altered cardiac function is a well-documented complication of human diabetic pregnancy, but its pathophysiology is still largely unknown. Our aim was to explore the mechanisms of fetal cardiac remodeling and cardiovascular hemodynamics in a rat model of maternal pregestational streptozotocin-induced hyperglycemia. The hyperglycemic group comprised 107 fetuses (10 dams) and the control group 219 fetuses (20 dams). Fetal cardiac function was assessed serially by Doppler ultrasonography. Fetal cardiac to thoracic area ratio, newborn heart weight, myocardial cell proliferative and apoptotic activities, and cardiac gene expression patterns were determined. Maternal hyperglycemia was associated with increased cardiac size, proliferative, apoptotic and mitotic activities, upregulation of genes encoding A- and B-type natriuretic peptides, myosin heavy chain types 2 and 3, uncoupling proteins 2 and 3, and the angiogenetic tumor necrosis factor receptor superfamily member 12A. The genes encoding Kv channel-interacting protein 2, a regulator of electrical cardiac phenotype, and the insulin-regulated glucose transporter 4 were downregulated. The heart rate was lower in fetuses of hyperglycemic dams. At 13-14 gestational days, 98% of fetuses of hyperglycemic dams had holosystolic atrioventricular valve regurgitation and decreased outflow mean velocity, indicating diminished cardiac output. Maternal hyperglycemia may lead to accelerated fetal myocardial growth by cardiomyocyte hyperplasia. In fetuses of hyperglycemic dams, expression of key genes that control and regulate cardiomyocyte electrophysiological properties, contractility, and metabolism are altered and may lead to major functional and clinical implications on the fetal heart.

B-type natriuretic peptide and severity of cognitive disorder.

BACKGROUND: Natriuretic peptides have been linked to cognitive disorder in previous studies. The aim of this study was to examine the association between the severity of cognitive disorder and the levels of B-type natriuretic peptide (BNP) in an older general population. MATERIAL AND METHODS: This study is a part of the larger population-based, multidisciplinary Kuopio 75+ health study. A total of 601 subjects aged 75 or older participated in the study. A subgroup of 126 individuals was diagnosed with cognitive disorder, and the severity of the disease was assessed. The participants were tested for BNP. Analysis of covariance was carried out to study the relationship between BNP and the stage of cognitive disorder. RESULTS: The association between the level of cognitive disorder and BNP resembled an inverse U-shaped curve, with higher levels of BNP observed among participants with mild cognitive disorder when compared to cognitively intact participants or counterparts with more severe cognitive disorder. This effect remained after adjustment for age (P = 0.02). However, association between BNP and level of cognitive disorder was lost in further adjustment with covariates connected to the levels of BNP. CONCLUSION: The previously reported elevation of natriuretic peptides among individuals with diagnosed cognitive disorder was found only in people with milder stages of the disorder.

Neurogenic pulmonary edema in patients with nontraumatic intracerebral hemorrhage: predictors and association with outcome.

BACKGROUND: Neurogenic pulmonary edema (NPE) is a well-recognized phenomenon after intracranial insult. In this study, we evaluated the predictors for NPE and its association with outcome in patients with intensive care unit-treated nontraumatic intracranial hemorrhage. METHODS: This was a prospective, observational clinical study in a university-level intensive care unit. Clinical characteristics, level of consciousness, and Acute Physiology and Chronic Health Evaluation (APACHE) II score were recorded on admission and the findings of primary head computed tomography were reviewed. A chest radiograph and arterial blood gas analysis were taken serially and NPE was determined as acute bilateral infiltrates in chest radiograph and hypoxemia. Echocardiography and cardiac and inflammatory markers were recorded. The 1-year outcome was assessed using the Glasgow Outcome Scale. RESULTS: NPE developed in 38 (35%) of the 108 patients included. Predictors for NPE were higher APACHE II score (≥20, odds ratio 6.17, P = 0.003) and higher interleukin-6 plasma concentration (>40 pg/mL, odds ratio 5.62, P = 0.003). Of patients with 0, 1, or 2 predictors mentioned above, 4%, 37%, and 65% had NPE, respectively. NPE was associated with a higher 1-year mortality (37% vs 14%, P = 0.007, respectively), but with an unchanged functional outcome after 1 year (Glasgow Outcome Scale score 1-3, 53% vs 51%, P > 0.9). CONCLUSIONS: Predictors for NPE are the severity of disease defined by APACHE II scores and higher levels of systemic inflammatory mediators. NPE is associated with a higher 1-year mortality, but not with a poorer 1-year functional outcome.

Collagen XV is necessary for modeling of the extracellular matrix and its deficiency predisposes to cardiomyopathy.

RATIONALE: The extracellular matrix (ECM) is a major determinant of the structural integrity and functional properties of the myocardium in common pathological conditions, and changes in vasculature contribute to cardiac dysfunction. Collagen (Col) XV is preferentially expressed in the ECM of cardiac muscle and microvessels. OBJECTIVE: We aimed to characterize the ECM, cardiovascular function and responses to elevated cardiovascular load in mice lacking Col XV (Col15a1(-/-)) to define its functional role in the vasculature and in age- and hypertension-associated myocardial remodeling. METHODS AND RESULTS: Cardiac structure and vasculature were analyzed by light and electron microscopy. Cardiac function, intraarterial blood pressure, microhemodynamics, and gene expression profiles were studied using echocardiography, telemetry, intravital microscopy, and PCR, respectively. Experimental hypertension was induced with angiotensin II or with a nitric oxide synthesis inhibitor. Under basal conditions, lack of Col XV resulted in increased permeability and impaired microvascular hemodynamics, distinct early-onset and age-dependent defects in heart structure and function, a poorly organized fibrillar collagen matrix with marked interstitial deposition of nonfibrillar protein aggregates, increased tissue stiffness, and irregularly organized cardiomyocytes. In response to experimental hypertension, Col15a1 gene expression was increased in the left ventricle of wild-type mice, and mRNA expression of natriuretic peptides (ANP and BNP) and ECM modeling were abnormal in Col15a1(-/-) mice. CONCLUSIONS: Col XV is necessary for ECM organization in the heart, and for the structure and functions of microvessels. Col XV deficiency leads to a complex cardiac phenotype and predisposes the subject to pathological responses under cardiac stress.

Tezosentan inhibits uptake of proinflammatory endothelin-1 in stenotic aortic valves.

BACKGROUND AND AIM OF THE STUDY: Aortic valve stenosis (AS) is an actively regulated pathobiological process which has an inflammation origin, and manifests as an accumulation of lipids and, ultimately, calcification of the aortic valve tissue. Increased plasma levels of the proinflammatory factor endothelin-1 (ET-1) have been reported in AS. Moreover, increased tissue levels of ET-1 and its ET(A) receptor, which mediates the fibrotic and proliferative effects of ET-1, have been reported in stenotic aortic valves. The study aim was to determine whether endothelin receptor antagonism has an effect on the supposed receptor-mediated uptake of ET-1 to aortic valves when ET-1 may be involved in the pathogenesis of AS. METHODS: By using valve tissue explants in culture, it was determined whether the ET(A)-ET(B) receptor antagonist tezosentan was capable of reducing the uptake of 125I-labeled ET-1 to human aortic valves. Aortic valves were obtained from 16 patients (11 males, five females; mean age 71 +/- 11.2 years) and from two donors without AS (as controls) at the time of aortic valve or aortic root surgery. Valve tissue samples were cultured in ET-1 (10 nmol/l), in the presence or absence of tezosentan (10 nmol/l). RESULTS: ET-1 uptake was found to be pronounced in the calcified areas of the valve, and tezosentan markedly reduced the receptor-mediated uptake of 125I-labeled ET-1. The inhibitory effect was most evident in the well-calcified part of the valve. The gene expression levels of the ET receptors ET(A) and ET(B) were unaltered in human aortic valves during a four-day exposure to the antagonist. CONCLUSION: The ability of the ET(A)-ET(B) receptor antagonist tezosentan to inhibit ET-1 uptake in valve tissue suggests that continuous ET antagonist therapy might serve as new strategy to slow down the pathophysiological processes of AS.

Key roles of endothelin-1 and p38 MAPK in the regulation of atrial stretch response.

Mechanisms regulating stretch response in the left ventricle are investigated in detail but not well understood in atrial myocardium. Hypertrophic growth of atrial myocardium contributes to the pathogenesis of atrial fibrillation. In this study, we sought to elucidate mechanisms of stretch-induced activation of key signaling pathways and hypertrophy-associated genes in rat atria. Stretching of isolated atria induced a rapid increase in phosphorylation of p38 MAPK and ERK and induced a p38 MAPK-dependent increase in DNA binding activity of transcription factors Elk-1 and GATA-4. Inhibition of the ERK pathway had no effect on the cardiac transcription factors studied. Stretch-induced increase in atrial contractile function was substantially enhanced by inhibition of p38 MAPK. p38 MAPK also regulated stretch-induced increase in c-fos, ß-myosin heavy chain, B-type natriuretic peptide mRNA levels, and atrial natriuretic peptide secretion in isolated atria. Various autocrine/paracrine factors are known to mediate the stretch response in the left ventricle. Stretching of isolated atria resulted in a robust increase in endothelin-1 (ET-1) mRNA levels, while apelin and adrenomedullin signaling cascades were downregulated. Administration of mixed ET(A/B) receptor antagonist bosentan attenuated the stretch-induced activation of GATA-4 in isolated atria, whereas ANG II receptor type-1 antagonist CV-11974 had no effect. Moreover, analysis of RNA from intact atrial and ventricular myocardium revealed significantly higher mRNA levels of ET(A) receptor and ET converting enzyme-1 in atrial compared with ventricular myocardium. In conclusion, our findings identify the local ET-1 system and p38 MAPK as key regulators of load-induced hypertrophic response in isolated rat atria.

Natriuretic peptides and collagen biomarkers in patients with medical treatment for hypertension.

OBJECTIVE: The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT-BPLA) showed that an amlodipine-based regimen prevented more cardiovascular events than an atenolol-based regimen in patients at high risk of hypertension.The basis of this difference is partly unknown and may be due to their divergent effects on the remodelling process of hypertensive heart disease. METHODS AND RESULTS: We measured plasma levels of aminoterminal propeptide of atrial natriuretic peptide (NT-proANP) and aminoterminal propeptide of B-type natriuretic peptide and serum levels of the aminoterminal propeptide of type I procollagen (PINP), aminoterminal propeptide of type III procollagen and type I collagen telopeptide in 93 patients randomized in the ASCOT study at baseline and after two and four years and compared them with echocardiographic parameters and blood pressure. NT-proANP decreased at two years by 22 (-484 - 153) pmol/l in the amlodipine-based regimen and increased by 109 (-297 - 1545) pmol/l in the atenolol-based regimen (P < 0.001), whereas no significant difference in NT-proBNP between the arms was found. PINP levels increased by 1.8 (-29 -31) microg/l in the amlodipine-based regimen and decreased by 4.7 (-27- 31) microg/I in the atenolol-based regimen, whereas no differences were found in other collagen markers between the arms. Major echocardiographic changes were not found. CONCLUSIONS: Our results show that the two treatment regimens of ASCOT-BPLA had different effects on plasma natriuretic peptides and serological markers of collagen turnover, probably reflecting divergent effects in cardiac remodelling.

A single intra-articular dose of vitamin D analog calcipotriol alleviates synovitis without adverse effects in rats.

1,25-dihydroxyvitamin-D3 and its derivatives have shown anti-arthritic and chondroprotective effects in experimental animal models with prophylactic dosing. The purpose of this preliminary study was to test the efficacy and safety of calcipotriol, vitamin D analog, as a treatment for a fully-developed knee arthritis in Zymosan-induced arthritis (ZIA) model. Forty 5-month-old male Sprague-Dawley rats were randomized into three arthritis groups and a non-arthritic control group with no injections (10 rats/group). A day after Zymosan (0.1 mg) had been administrated into the right knee joints, the same knees were injected with calcipotriol (0.1 mg/kg), dexamethasone (0.1 mg/kg) or vehicle in a 100 µl volume. The left control knees were injected with saline (PBS) on two consecutive days. All injections, blood sampling and measurements were performed under general anesthesia on days 0, 1, 3 and 8. Internal organs and knees were harvested on day 8 and the histology of the whole knees was assessed blinded. Joints treated with calcipotriol showed a milder histological synovitis than those treated with vehicle (p = 0.041), but there was no statistically significant difference between the dexamethasone and vehicle groups. The clinical severity of arthritis did not differ between the arthritis groups measured by body temperature, swelling of the knee, thermal imaging, clinical scoring or cytokine levels on days 1, 3 and 8. Weight loss was bigger in rats treated with dexamethasone, propably due to loss of appetite,compared to other arthritis groups on days 2-3 (p<0.05). Study drugs did not influence serum calcium ion and glucose levels. Taken together, this preliminary study shows that a single intra-articular injection of calcipotriol reduces histological grade of synovitis a week after the local injection, but dexamethasone did not differ from the vehicle. Calcipotriol may have an early disease-modifying effect in the rat ZIA model without obvious side effects.

Characterization of molecular forms of N-terminal B-type natriuretic peptide in vitro.

BACKGROUND: The heterogeneity of circulating peptides may influence the interpretation of results from N-terminal profragment of BNP (NT-proBNP) assays. Our objective was to characterize the heterogeneity for better usability of the assays. METHODS: Endogenous proBNP was purified from patient samples and treated with trifluoromethanesulfonic acid (chemical deglycosylation). The human proBNP gene was introduced into rat hearts by adenoviral transfer. Cell lysates and plasma samples containing proBNP-derived peptides were analyzed by chromatography. The fate of exogenous recombinant NT-proBNP added to fresh whole blood samples was followed by immunoassays and chromatography. The main NT-proBNP components were isolated and identified by mass spectrometry. RESULTS: Immunoreactive NT-proBNP in human plasma comprised several molecular forms, as did circulating immunoreactive human NT-proBNP after adenoviral transfer of human proBNP cDNA into rat ventricular myocardium. Incubation of recombinant NT-proBNP(1-76) in human plasma or serum resulted in multiple components with the 2 major components identified as NT-proBNP(1-36) and NT-proBNP(1-62/64). Profiling by different antisera and chromatography indicated masking of the non-mid-region epitopes likely due to formation of oligomers. More than 75% of the original immunoreactivity in the mid-region epitope was retained after 3-week storage of plasma samples at room temperature. CONCLUSIONS: There is marked heterogeneity in immunoreactive NT-proBNP in plasma not related to glycosylation. The mid-region epitope of NT-proBNP is stable even in harsh storage conditions. Careful choice of antibody epitopes can yield extraordinarily robust assays.

Increase in tissue endothelin-1 and ETA receptor levels in human aortic valve stenosis.

AIMS: Aortic valve stenosis (AS) is an actively regulated process like atherosclerosis, which is accompanied by changes e.g. in endothelin-related genes. However, the role of endothelin peptides in AS is unknown. METHODS AND RESULTS: We characterized the expression of the endothelin system in aortic valves of patients with normal valves (n = 12), regurgitation, and fibrosis (n = 6) and AS (n = 18) by reverse-transcriptase-polymerase chain reaction and immunohistochemistry. The number of endothelin-1 (ET-1) positive cells was higher in AS than in control valves, while levels of ET-1 mRNA did not differ between groups. Endothelin receptor-A (ET(A)) mRNA levels were upregulated in stenotic valves (4.3-fold, P = 0.032) associated with a remarkable increase in number of ET(A)-immunopositive cells. ET(B)-receptor mRNA levels did not change during disease progression. Endothelin-converting enzyme-1 (ECE-1) mRNA levels were 42% lower (P = 0.007) in stenotic valves. Finally, because ET-1 and ECE-1 have binding site for activator protein-1 (AP-1), we measured AP-1 DNA binding by gel shift assays, which showed significantly lower (76%, P = 0.003) activity in AS. CONCLUSION: AS is characterized by distinct upregulation of ET-1 and its target receptor ET(A), promoting growth, inflammation, and fibrosis. These findings suggest therapeutic potential for ET(A)-receptor antagonists in aortic valve calcification.

Apelin and its receptor APJ in human aortic valve stenosis.

BACKGROUND AND AIM OF THE STUDY: Aortic valve stenosis (AS) is an actively regulated pathobiological process that shows some hallmarks of atherosclerosis. Apelin and its receptor, APJ, are highly expressed in the heart, and the proposed effects of the apelin-APJ system are opposite to those of the angiotensin II-AT1-receptor pathway. The role of the apelin-APJ signaling pathway in calcified aortic valve disease is unknown. METHODS: The study involved the characterization and comparison of expression of apelin and APJ as well as angiotensin II receptors (AT1 and AT2) in the aortic valves of patients with normal valves (n = 6), aortic regurgitation (n = 9 AR), regurgitation and fibrosis/mild sclerosis (n = 14), and AS (n = 25). RESULTS: By employing the reverse-transcriptase polymerase chain reaction (RT-PCR), the gene expression of apelin (3.63-fold, p = 0.001) and the APJ receptor (2.70-fold, p = 0.01) were shown to be significantly up-regulated in stenotic valves when compared to controls. In addition, APJ receptor mRNA levels were higher (2.9-fold, p = 0.010) in the AR + sclerosis group when compared to controls. Using immunohistochemistry, apelin was shown to be localized in stenotic aortic valves to the valvular endothelial layer of the aortic valve, to vascular endothelial cells in neovessels, and to fibroblasts and macrophages adjacent to vessels in the stromal area. AT2-receptor mRNA levels were 90% (p < 0.001) lower in stenotic valves. In contrast, the gene expression of AT1-receptors did not differ significantly among the groups. CONCLUSION: Aortic valve stenosis is characterized by an up-regulation of the apelin-APJ signaling pathway, revealing a possible novel target for drug discovery in calcified aortic valve disease by suppressing chemotaxis, angiogenesis and osteoblast activity, all of which are well-documented phenomena in the disease process.