Role of Cardiac A2A Receptors Under Normal and Pathophysiological Conditions.

This review presents an overview of cardiac A2A-adenosine receptors The localization of A2A-AR in the various cell types that encompass the heart and the role they play in force regulation in various mammalian species are depicted. The putative signal transduction systems of A2A-AR in cells in the living heart, as well as the known interactions of A2A-AR with membrane-bound receptors, will be addressed. The possible role that the receptors play in some relevant cardiac pathologies, such as persistent or transient ischemia, hypoxia, sepsis, hypertension, cardiac hypertrophy, and arrhythmias, will be reviewed. Moreover, the cardiac utility of A2A-AR as therapeutic targets for agonistic and antagonistic drugs will be discussed. Gaps in our knowledge about the cardiac function of A2A-AR and future research needs will be identified and formulated.

Ex vivo comparison of CBCT and digital periapical radiographs for the quantitative assessment of periodontal defects.

OBJECTIVES: Accurate imaging is essential for effective treatment planning in periodontology. The aim of this ex vivo study was to investigate the accuracy of cone beam computed tomography (CBCT) and digital periapical radiographs (PA) in imaging periodontal defects. Hypotheses are: 1. That CBCT is a more accurate method than PA concerning vertical measurements of periodontal bone defects2. That CBCT itself is an accurate method to describe vertical periodontal bone loss MATERIAL AND METHODS: In this study, 117 periodontal defects from 10 human cadavers were investigated radiographically by CBCT and PA by one calibrated observer. Afterwards the vertical bone loss was measured with a periodontal probe by the same calibrated observer. Differences between radiographic and clinical measurements were calculated and analyzed. Bland-Altmann plots including 95% limits of agreement were calculated. RESULTS: The 95% limits of agreement ranged from 3.29 to -3.27 mm between clinical measurements and measurements in PAs, and from 2.13 to -1.97 mm in CBCTs. The mean difference between clinical and radiographic measurements was 0.0009 mm for PA and 0.0835 mm for CBCT. CONCLUSIONS: When comparing the clinical measurements, CBCT had a higher agreement and less deviations than PAs, and CBCT seems to be an accurate method to describe vertical periodontal bone loss. CLINICAL RELEVANCE: Accurate description of defects is helpful for accurate treatment planning.

Household air pollution in Nairobi's slums: A long-term policy evaluation using participatory system dynamics.

58% of Nairobi's population live in informal settlements in extremely poor conditions. Household air pollution is one of the leading causes of premature death and disease in these settlements. Regulatory frameworks and government budgets for household air pollution do not exist and humanitarian organisations remain largely inattentive and inactive on this issue. The purpose of this paper is to evaluate the effectiveness of potential indoor-air related policies, as identified together with various stakeholders, in lowering household air pollution in Nairobi's slums. Applying a novel approach in this context, we used participatory system dynamics within a series of stakeholder workshops in Nairobi, to map and model the complex dynamics surrounding household air pollution and draw up possible policy options. Workshop participants included community members, local and national policy-makers, representatives from parastatals, NGOs and academics. Simulation modelling demonstrates that under business-as-usual, the current trend of slowly improving indoor air quality will soon come to a halt. If we aim to continue to substantially reduce household PM2.5 levels, a drastic acceleration in the uptake of clean stoves is needed. We identified the potentially high impact of redirecting investment towards household air quality monitoring and health impact assessment studies, therefore raising the public's and the government's awareness and concern about this issue and its health consequences. Such investments, due to their self-reinforcing nature, can entail high returns on investment, but are likely to give 'worse-before-better' results due to the time lags involved. We also discuss the usefulness of the participatory process within similar multi-stakeholder contexts. With important implications for such settings this work advances our understanding of the efficacy of high-level policy options for reducing household air pollution. It makes a case for the usefulness of participatory system dynamics for such complex, multi-stakeholder, environmental issues.

Indicadores biológicos séricos em veado-campeiro ( Ozotoceros bezoarticus bezoarticus, Linnaeus 1758) de vida livre do Pantanal Sul-Mato-Grossense / Serum biological indicators in free-living pampas deer (Ozotoceros bezoarticus bezoarticus, Linnaeus 1758) of the Pantanal Sul-Mato-Grossense

O objetivo com este estudo foi estabelecer os intervalos de referência de diferentes analitos séricos em Ozotoceros bezoarticus bezoarticus de vida livre. Foram coletadas amostras de sangue de 54 fêmeas e 14 machos adultos, capturados no Pantanal de Mato Grosso do Sul. A determinação das concentrações de cálcio total, albumina, colesterol total, creatinina, glicose, fósforo, proteína total, triglicerídeos e ureia séricas e a atividade das enzimas alanina aminotransferase, aspartato aminotransferase, creatina quinase fração MB e fosfatase alcalina foi realizada em equipamento automático. Valores de globulinas, cálcio total e proporções (razões) entre analitos foram realizados por meio de cálculo matemático. Esta é a primeira descrição do intervalo de referência de parâmetros bioquímicos séricos em veado-campeiro de vida livre do Pantanal de Mato Grosso do Sul. O tamanho da amostra e a distribuição dos dados indicam que os valores médios obtidos são representativos e podem ser usados para a monitorização da saúde, do estado nutricional e do diagnóstico de enfermidades nesse estrato populacional.(AU)

The objective of the present study is to establish the reference intervals of different serum analytes in free - living Ozotoceros bezoarticus bezoarticus. Blood samples were drawn from the 54 females and 14 males, adults, captured in the Pantanal of Mato Grosso do Sul. A determination of total calcium, albumin, total cholesterol, creatinine, glucose, phosphorus, total protein, triglycerides, and serum urea concentrations and an activity of the enzymes alanine aminotransferase, aspartate aminotransferase, creatine kinase MB fraction and alkaline phosphatase were performed in automated equipment. Values of globulins, total calcium and proportions among analytes were performed by means of mathematical calculations. This is a first description of the reference parameters for serum biochemistry of free - living pampas deer in the Pantanal of Mato Grosso do Sul. Sample size and distribution of data indicate that the mean values obtained are representative and can be used for a health monitoring, nutritional status, and diagnosis of diseases in this population stratum.(AU)

Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques.

INTRODUCTION: The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). METHODS: Patients (n = 19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n = 19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. RESULTS: Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. CONCLUSION: Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies.

[Comparison of the Results of the Flicker Perimetry (Prototype versus Commercial Perimeter)]. / Vergleich der Ergebnisse der Flimmerperimetrie (Prototyp versus kommerziellem Perimeter).

Background: Analysis of the comparison of flicker perimetry with the prototype Pulsar and the new Octopus 600. Methods: Both eyes of 20 patients with primary open-angle glaucoma were studied with 30° visual field flimmer perimetry (dynamic strategy) at the perimeters Pulsar and Octopus 600 (Haag-Streit). The evaluation was based on the mean defect (MD = mean deviation) and the defect depth (square root of lost variance = sLV). Results: In the t test for paired samples, the Pulsar perimetry showed significantly higher values than the Octopus 600 perimetry: right eye MD 4.8 ± 3.6 src vs. 1.7 ± 2.9 src, p = 0.005; left eye MD 3.9 ± 3.6 src v. 1.4 ± 2.8 src, p = 0.018; both eyes MD 4.35 ± 3.62 src vs. 1.55 ± 2.80 src, p = 0.002. The sLV values with the Pulsar perimetry were significantly higher than the values with the Octopus 600 perimetry: right eye sLV 3.6 ± 1.6 vs. 2.3 ± 1.3 src, p = 0.006; left eye sLV 3.2 ± 0.8 vs. 2.0 ± 0.8 src, p < 0.0001; both eyes sLV 3.37 ± 1.28 src vs. 2.12 ± 1.05 src, p < 0.0001. The significances even persisted after the Bonferroni-Holm correction. Conclusion: The investigation results of flicker perimetry are not comparable, because there is a significant difference in MD and sLV. This mainly due to different light intensities, background brightness and varying colour scalings of the perimetric device.

[Aids for Patients with Glaucoma and Visual Impairment]. / Hilfsmittel für Patienten mit Glaukom und Sehbehinderung.

This article provides a broad overview of the existing medical aids and appliances for patients suffering from glaucoma and/or visual impairment. Furthermore, instructions for proper handling of eye drop therapy are given. There are many different public services to support patients with visual impairment and that aim to restore their mobility and autonomy in daily life. About 20,000 medical aids and tools are currently listed as refundable by insurances. The available supply ranges from magnifying reading aids to electronic aids and appliances to train patients' orientation, mobility and skills of every day life. Qualified professionals may be employed by organisations such as the DBSV e. V. and can accompany, support and counsel patients and their families with their specialised knowledge.

Déficits primários e secundários de funções executivas pós-TCE: análise de dissociações / Primary and secondary executive function deficits following TBI: analysis of dissociations

Este estudo avaliou as associações e dissociações encontradas entre déficits de memória episódica em relação aos de funções executivas e verificou se estes déficits encontrados eram primários ou secundários. Os 81 pacientes pós-Traumatismo Cranioencefálico (TCE) foram avaliados por meio do Teste de Aprendizagem Auditivo-Verbal de Rey e do Teste Hayling. Os resultados sugerem que prejuízo na velocidade de controle inibitório pode contribuir para déficit na memória episódica e que as velocidades de iniciação e inibição parecem ser complementares, mas a primeira precede a segunda. Nossos achados ressaltam que os prejuízos executivos provavelmente sejam primários em nossa amostra de pacientes pós-TCE e que estes prejuízos podem causar déficits na memória episódica (AU)

Déficits primários e secundários de funções executivas pós-TCE: análise de dissociações / Primary and secondary executive function deficits following TBI: analysis of dissociations

Este estudo avaliou as associações e dissociações encontradas entre déficits de memória episódica em relação aos de funções executivas e verificou se estes déficits encontrados eram primários ou secundários. Os 81 pacientes pós-Traumatismo Cranioencefálico (TCE) foram avaliados por meio do Teste de Aprendizagem Auditivo-Verbal de Rey e do Teste Hayling. Os resultados sugerem que prejuízo na velocidade de controle inibitório pode contribuir para déficit na memória episódica e que as velocidades de iniciação e inibição parecem ser complementares, mas a primeira precede a segunda. Nossos achados ressaltam que os prejuízos executivos provavelmente sejam primários em nossa amostra de pacientes pós-TCE e que estes prejuízos podem causar déficits na memória episódica

The present study evaluated the presence of associations and dissociations between impairments in episodic memory and executive functions in patients with traumatic brain injury (TBI), and verified whether these deficits were primary or secondary. Eighty-one patients with TBI were assessed using the Rey Auditory Verbal Learning Test and the Hayling Test. The results suggest that impairments in inhibition speed may contribute to deficits in episodic memory, and that initiation and inhibition abilities may be complementary and the first precedes the second. Our findings highlighted that primary executive impairment following TBI may lead to episodic memory deficits

Genomics of the divergence continuum in an African plant biodiversity hotspot, I: drivers of population divergence in Restio capensis (Restionaceae).

Understanding the drivers of population divergence, speciation and species persistence is of great interest to molecular ecology, especially for species-rich radiations inhabiting the world's biodiversity hotspots. The toolbox of population genomics holds great promise for addressing these key issues, especially if genomic data are analysed within a spatially and ecologically explicit context. We have studied the earliest stages of the divergence continuum in the Restionaceae, a species-rich and ecologically important plant family of the Cape Floristic Region (CFR) of South Africa, using the widespread CFR endemic Restio capensis (L.) H.P. Linder & C.R. Hardy as an example. We studied diverging populations of this morphotaxon for plastid DNA sequences and >14 400 nuclear DNA polymorphisms from Restriction site Associated DNA (RAD) sequencing and analysed the results jointly with spatial, climatic and phytogeographic data, using a Bayesian generalized linear mixed modelling (GLMM) approach. The results indicate that population divergence across the extreme environmental mosaic of the CFR is mostly driven by isolation by environment (IBE) rather than isolation by distance (IBD) for both neutral and non-neutral markers, consistent with genome hitchhiking or coupling effects during early stages of divergence. Mixed modelling of plastid DNA and single divergent outlier loci from a Bayesian genome scan confirmed the predominant role of climate and pointed to additional drivers of divergence, such as drift and ecological agents of selection captured by phytogeographic zones. Our study demonstrates the usefulness of population genomics for disentangling the effects of IBD and IBE along the divergence continuum often found in species radiations across heterogeneous ecological landscapes.

[Corneal endothelial cell density and its correlation with the severity of pseudoexfoliation]. / Hornhautendothelzelldichte in Abhängigkeit vom Schweregrad der Pseudoexfoliation.

INTRODUCTION: Pseudoexfoliation (PEX) syndrome is a common, age-related disease which is associated with the multifocal deposition of fibrillar PEX material in intra- and extraocular tissues. Subsequently among others second chronic open-angle glaucoma and corneal endothelial cell loss occurs. The present study analysed whether there is a correlation between the stage of the PEX process and corneal endothelial cell density (cECD), regardless of the non-existence or proof of secondary glaucoma. MATERIALS AND METHODS: One eye of 109 Caucasian subjects (mean age 71.7 years) was examined by slit-lamp microscopy and classified based on visible PEX deposits on the lens (mild and severe) and presence of glaucoma in 4 study groups. The control groups were healthy subjects and patients with primary open angle glaucoma (POAG). The cECD was measured with the endothelial cell mirror microscope (SeaEagle). RESULTS: All study groups and the POAG group showed a significant cECD reduction compared to the healthy control group: POAG: 6.0 %; PEX syndrome: mild 5.5 % and severe 11.0 %, PEX glaucoma: mild 7.7 % and severe 12.3 %. Further the cECD was significantly lower compared to the POAG group in severe PEX syndrome by 5.4 % and in severe PEX glaucoma by 6.8 %. cECD significantly decreased with increasing PEX stage independently of the presence of glaucoma. These differences remained statistically significant after Bonferroni-Holm correction. The analysis of the entire group of test subjects showed only a weak correlation between mean intraocular pressure and mean cECD. CONCLUSION: The results of this study showed a decreasing cECD with increasing PEX stage, regardless of whether glaucoma is present or not. The influence of the PEX process appears to be more pronounced than the influence of intraocular pressure.

[Immunoassay for matrix metalloproteinase-9 in the tear film of patients with pseudoexfoliation syndrome - a pilot study]. / Immunoassay für Matrix-Metalloproteinase-9 in der Tränenflüssigkeit bei Patienten mit Pseudoexfoliationssyndrom - eine Pilotstudie.

INTRODUCTION: Matrix-metalloproteinases (MMPs) are proteolytic enzymes released by irritated epithelial cells of the ocular surface. It has been established that the subtype MMP-9 can serve as an inflammatory marker within the tear film. MMP-9 is also attributed to have an effect on the PEX-glaucoma development. Recently, a rapid immunoassay for detection of MMP-9 in the tear film was developed to estimate inflammatory extent during dry eye disease. The aim of this study was to analyse the MMP-9 concentration in tear film in PEX-syndrome. In addition, an assessment of the feasibility, reliability and readability of the test was done. METHODS: We randomly selected 10 patients with PEX-syndrome and 10 healthy control patients and measured tear film MMP-9 of one eye with the RPS InflammaDry Detector™ (Rapid Pathogen Screening Inc., USA). RESULTS: We detected increased levels of MMP-9 in tear film in PEX-syndrome. 80 % of the PEX-patients and 20 % of the controls showed a positive test result (>or= 40 ng/mL MMP-9) indicating a test specificity and sensitivity of 80 %. This corresponds approximately to the published values for the dry eye (sensitivity 87 %, specificity: 92 %). The performance of the test is simple. The patients tolerated the inclusion of the test strips well. However, it is difficult to estimate whether enough tear film was used and in many cases, the intensity of the "indicator line" was weak. CONCLUSION: The rapid MMP-9-immunoassay is a novel, meaningful approach for the detection of inflammatory activity of the ocular surface. We have shown an up-regulation of the non-specific inflammatory marker MMP-9 in tear film in PEX-syndrome and suggest an association with a tear film disorder. However, an improvement in the estimation of the amount of collected tears and readability is desirable.

[Therapeutic strategies in dry eye disease--a survey of possible substitution therapies and causal therapeutic approaches]. / Therapiestrategien beim trockenen auge--eine übersicht über mögliche substitutionstherapien und kausaltherapeutische ansätze.

Substitution therapy with artificial tears is the standard in dry eye disease. Nowadays there are a vast variety of different preparations. This article gives an overview of both new and old approaches to substitution therapy (one-, two- and three-phase preparations) as well as opportunities for the causal treatment. Here, we provide dry eye treatment options regarding sophisticated disease subgroups, classifications concerning the affected tear film layer (aqueous, mucinous or lipid phase), and immunological dysfunctions.

Diagnostic value of palpation, mammography, and ultrasonography in the diagnosis of fibroadenoma: impact of breast density, patient age, ultrasonographic size, and palpability.

PURPOSE: This retrospective study aimed to assess the diagnostic value of mammography, breast ultrasonography, and palpation in diagnosing fibroadenomas, making consistent use of the BI-RADS classification. The impact of breast density, patient age, and the size and palpability of the mass will be evaluated. PATIENTS AND METHODS: Between January 2000 and December 2009, a total of 339 fibroadenomas suitable for inclusion in this study were diagnosed and histologically verified at our institution. Based on their BI-RADS or BI-RADS analog classification, all lesions were categorized as benign or malignant. These results were compared to the corresponding histopathological findings. Specificities were calculated for each of the abovementioned parameters. Chi-square test results with p-values < 0.05 were considered significant. Congruence between mammography and ultrasonography was assessed based on Cohen's kappa. RESULTS: Palpation had a specificity of 100 %, mammography 83.9 %, and ultrasonography 88.2 %. Considering the parameters under investigation, ultrasonography is superior to mammography. The specificity of the ultrasonographic assessment "benign" vs. "malignant" varied with patient age and palpability of the lesion (p = 0.001 and p = 0.025). Mammography and ultrasonography were most congruent for lesions rated ACR 1 - 2 and for lesions > 1.9 cm (κ = 0.464, κ = 0.444). CONCLUSION: For diagnosing fibroadenomas, ultrasonography is more specific than mammography when all examined variables are taken into account. Ultrasonography should therefore be favored, especially in younger patients. One needs to be aware of the effects of palpability and patient age on the ultrasonographic differentiation "malignant" vs. "benign". In some cases, mammography should be considered as an adjunct.

Human 6-sulfo LacNAc (slan) dendritic cells are a major population of dermal dendritic cells in steady state and inflammation.

BACKGROUND: The immune system of the skin has a network of resident dendritic cells (DCs) consisting of epidermal Langerhans cells and various subsets of dermal DCs. We recently reported on a new population of dermal DCs, called slan (6-sulfoLacNAc+) DCs, which have a potent capacity to stimulate Th17/Th1 T-cell responses. AIM: To understand the characteristics of slanDCs as a new population of dermal DCs in the context of other DC populations in healthy and psoriatic skin. METHODS: We immunofluorescently stained skin samples from healthy controls and from patients with psoriasis. RESULTS: Staining healthy skin for DCs showed that slanDCs (CD1a- CD1c- CD11c- CD14- CD163-) were present at a similar frequency to that of CD1c+ CD11c+ CD1a+ CD14- CD163- dermal DCs, which have previously been regarded as the major population of resident DCs. In psoriatic skin, the frequency of slanDCs and CD1c+ DCs was doubled, and the slanDCs expressed CD11c. In-depth analysis of DCs in psoriatic skin by four-colour immunofluorescence analysis showed that the pool of CD11c+ cells could be further subdivided into CD11c+ CD14+ CD163- DCs and CD11c+ CD163+ CD14+ macrophages. CONCLUSION: SlanDCs, initially described as large population of proinflammatory DCs in blood, are a novel and major part of the resident dermal myeloid DC system in both healthy and inflamed skin.

Upper respiratory tract disease in captive orangutans (Pongo sp.): prevalence in 20 European zoos and predisposing factors.

BACKGROUND: Upper respiratory tract disease (URTD) is a significant cause of morbidity in captive orangutans (Pongo abelii, Pongo pygmaeus), and the pathogenesis is often unknown. METHODS: The prevalence of respiratory disease in captive European orangutans (201 animals; 20 zoos) and possible predisposing factors were investigated. RESULTS: Bornean orangutans (P. pygmaeus) showed chronic respiratory signs significantly more often (13.8%) than Sumatran (P. abelii; 3.6%), and males (15.8%) were more often afflicted than females (3.9%). Hand-reared animals (21%) developed air sacculitis more often than parent-reared animals (5%). Diseased animals were more often genetically related to animals with respiratory diseases (93%) than to healthy animals (54%). None of the environmental conditions investigated had a significant effect on disease prevalence. CONCLUSION: Results suggest a higher importance of individual factors for the development of URTD than environmental conditions. Bornean, male and hand-reared orangutans and animals related to diseased animals need increased medical surveillance for early detection of respiratory disease.

Siglec-F antibody administration to mice selectively reduces blood and tissue eosinophils.

BACKGROUND: Sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of receptors that bind sialic acid and mostly contain immunoreceptor tyrosine-based inhibitory motifs, suggesting that these molecules possess inhibitory functions. We have recently identified Siglec-8 as an eosinophil-prominent Siglec, and cross-linking of Siglec-8 on human eosinophils induces apoptosis. In this article, we address the in vivo consequences of Siglec engagement. We and others have identified mouse Siglec-F as the closest functional paralog of human Siglec-8, based on shared ligand-binding and expression pattern. We therefore hypothesized that Siglec-F engagement would affect levels and viability of eosinophils in vivo. METHODS: Wild type and hypereosinophilic mice were administered Siglec-F antibody and levels of eosinophils in peripheral blood and tissue were measured. Eosinophil apoptosis (in vivo and in vitro) was determined by binding of Annexin-V. RESULTS: Studies in IL-5 transgenic mice, displaying hypereosinophilia, show that administration of a single dose of Siglec-F antibody results in rapid reductions in quantum of eosinophils in the blood. This decrease was accompanied by reductions in tissue eosinophils. Quantum of eosinophils in blood was decreased using two separate antibodies, as well as in other mouse models (wild type mice and in a mouse model of chronic eosinophilic leukemia). Mechanistic studies demonstrated that Siglec-F antibody administration induced apoptosis of eosinophils in vivo and in vitro. CONCLUSION: These data demonstrate that activation of innate immune receptors, like Siglec-F, can significantly reduce mouse eosinophil viability. As such, targeting Siglec-8/F may be a therapeutic approach for eosinophilic disorders.

[Current stage of fMRI applications in newborns and children during the first year of life]. / Gegenwärtiger Stand der funktionellen MRT bei Neugeborenen und Kindern im ersten Lebensjahr.

Currently, a paradigm shift towards expanded early use of cranial MRI in newborns at risk and infants in the first year of life can be observed in neonatology. Beyond clinical MRI applications, there is progressive use of functional MRI (fMRI) in this age group. On the one hand, fMRI allows monitoring of functional developmental processes depending on maturational stage; on the other hand, this technique may provide the basis for early detection of pathophysiological processes as a prerequisite for functionally guided therapeutic interventions. This article provides a comprehensive review of current fMRI applications in neonates and infants during the first year of life and focuses on the associated methodological issues (e. g. signal physiology, sedation, safety aspects).

Different behaviour of soluble CD40L concentrations can be reflected by variations of preanalytical conditions.

INTRODUCTION: Biomarkers reflecting an inflammatory or immunological response are increasingly offered to improve the risk stratification of patients. For example, current evidence suggests that soluble CD40 ligand (sCD40L) is elevated in patients with acute coronary syndrome. But only a few data are available to evaluate the influence of preanalytic conditions on sCD40L values. METHODS: Blood samples of seven healthy blood donors were collected in tubes without additives and in EDTA- or citrate-filled tubes at various storage conditions. Platelet count was modified by serum dilution, and sCD40L was measured in platelet-rich-plasma and in whole blood. sCD40L levels were determined by an commercially available ELISA-Kit. RESULTS: Immediately after blood sample assessment, sCD40L levels in serum samples were elevated (1258+/-820 pg/ml) compared to EDTA (64+/-32 pg/ml) and citrate (60+/-8.5 pg/ml) values. Additionally, sCD40L levels were dependent on storage duration. After platelet activation, sCD40L levels were significantly increased to 8278+/-2453 pg/ml and were significantly correlated to platelet count (r=0.96). CONCLUSIONS: Soluble CD40L levels were clearly influenced by preanalytical conditions and were dependent on storage duration, sample technique and platelet count. These influences should be considered by the determination and evaluation of sCD40L concentrations.

Pyrazolinone analgesics prevent the antiplatelet effect of aspirin and preserve human platelet thromboxane synthesis.

BACKGROUND: Anti-inflammatory analgesics, including ibuprofen and naproxen, are known to interfere with the antiplatelet effect of aspirin, presumably as a result of a drug-drug interaction at the level of platelet cyclooxygenase-1 (COX-1). OBJECTIVE: We studied whether dipyrone, which has recently been reported to inhibit COX isoforms by a mechanism different from conventional non-steroidal anti-inflammatory drugs (NSAIDs), also interferes with the antiplatelet effect of aspirin. METHODS: Arachidonic acid- and collagen-induced aggregation, as well as thromboxane formation, were measured in human platelet-rich plasma. Platelet P-selectin expression was determined by flow cytometry and cell-free COX enzyme activity was quantified by luminol-enhanced luminescence of human platelet microsomes. In addition, computerized docking was performed based on the crystal structure of COX-1. RESULTS: 4-Methylaminoantipyrine (MAA), the active metabolite of dipyrone, largely attenuated or even completely abolished the inhibition of arachidonic acid-induced platelet aggregation, thromboxane formation and P-selectin expression by aspirin. Similar results were obtained for other pyrazolinones, as well as for the conventional NSAIDs ibuprofen and naproxen. Moreover, MAA attenuated the effect of aspirin on COX activity of platelet microsomes, suggesting a competition with aspirin at the COX-1 enzyme. This was confirmed by docking studies, which revealed that MAA forms a strong hydrogen bond with serine 530 within the COX-1, thereby preventing enzyme acetylation by aspirin. CONCLUSION: This study demonstrates for the first time that dipyrone and other pyrazolinones have a high potential to attenuate or prevent the antiplatelet effect of aspirin. This should be considered if pyrazolinone analgesics are administered to patients with cardiovascular disease requiring antiplatelet aspirin therapy.