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Biomedical subjects

G Riemekasten

Publications and source records attributed to G Riemekasten.

At least 19 recordsLinked to original sources
PubMed2006

[Pulmonary arterial hypertension in collagen disease: experiences of the German Network for Systemic Scleroderma].

The German Network for Systemic Scleroderma (Deutsches Netzwerk Für Systemische Sklerodermie [DNSS]) has as its aim to improve and standardize the diagnosis and treatment of this rare disease. 14.6 % of patients in the DNSS register have been shown to have pulmonary hypertension (PHT). Comparable international data range from 12 % to 26.7 %. The DNSS recommends annual echocardiography for patients with scleroderma and right-heart catheterization if the systolic pulmonary arterial pressure is higher than 35 mmHg. Aggressive immunosuppressive treatment--in the first instance with cyclophosphamide--should be given only if there is also progressive fibrosis. Drugs that lower the level of PHT also have a favourable effect on other signs of scleroderma.

Catheterization, Swan-Ganz↗
PubMed2006

Neutrophil respiratory burst is decreased in scleroderma and normalized by near-infrared mediated hyperthermia.

BACKGROUND: The production of reactive oxygen species (ROS) by fibroblasts has been suggested to contribute to scleroderma pathogenesis. Infrared-mediated hyperthermia has recently been shown to be of benefit in scleroderma. AIM: As the contribution of neutrophils and monocytes to ROS formation in scleroderma is unknown, we studied respiratory burst in these cell types. We also aimed to test the hypothesis that near-infrared (IRA) treatment may effect burst activity. METHODS: We determined respiratory burst in patients with scleroderma (n = 22) and age- and sex-matched controls (n = 20) at baseline, and after high-level stimulation by phorbolmyristyl acetate (PMA) and low-level stimulation by non-opsonized zymosan. Respiratory burst was also assessed before and after a series of infrared-mediated hyperthermia treatments. RESULTS: Unexpectedly, we observed no increase but instead a slight but statistically significant reduction in baseline and zymosan-stimulated respiratory burst in scleroderma neutrophils (P < 0.001) and monocytes (P < 0.005). This decrease in burst activity was nonspecific, as it was also observed in patients with another active inflammatory disease, psoriasis. IRA treatment induced a cell-type-specific normalization of respiratory burst only in neutrophils, but not in monocytes. Intriguingly, neutrophil-specific normalization of ROS formation persisted for 6 weeks after the end of IRA treatment, in concordance with the previously reported clinical responses to this therapy. CONCLUSION: Neutrophils and monocytes do not exhibit cell-autonomous overproduction of ROS in scleroderma, thereby implicating fibroblasts as main source for clinically relevant ROS accumulation. Furthermore, repeated mild infrared-mediated hyperthermia exerts a lasting cell-type-specific effect on neutrophils.

Adult↗
PubMed2006

The systemic and SmD183-119-autoantigen-specific cytokine memory of Th cells in SLE patients.

OBJECTIVES: The aim of the study was to analyse the cytokine memory of T-cells derived from systemic lupus erythematosus (SLE) patients and healthy donors enriched for autoantigen-specific T-cells by in vitro stimulation with SmD1(83-119), a common autoantigen in SLE. METHODS: Autoreactive CD3+ T-cells derived from 37 SLE patients and 14 healthy donors were enriched by repetitive ex vivo stimulation of peripheral blood mononuclear cells (PBMCs) with SmD1(83-119). For control, PBMCs were stimulated only with interleukin-2 (IL-2). After two rounds of antigenic stimulation, cultures were stimulated with PMA/ionomycin to probe the cytokine memory by intracellular cytokine staining. Frequencies of cytokine-expressing T-cells were analysed and, in SLE patients, compared with disease activities and autoantibody levels. RESULTS: Comparing the cytokine memory in the cultures, SLE patients displayed higher frequencies of tumour necrosis factor-alpha (TNF-alpha)+ T-cells than healthy donors and the frequencies correlated with disease activity. Frequencies of SmD1(83-119)-specific TNF-alpha+ T-cells and of memory T-cells expressing interferon-gamma (IFN-gamma) correlated with serum anti-dsDNA antibody levels. The frequencies of IL-10 expressing SmD1(83-119)-specific T-cells were lower among PBMCs of SLE patients. Relatively higher frequencies of IL-10+ T-cells in SLE patients correlated with low disease activities, and low anti-dsDNA and anti-SmD1(83-119) antibody concentrations in culture supernatants. CONCLUSIONS: The memory of autoreactive SmD1(83-119)-specific and unspecific stimulated peripheral Th cells for re-expression of cytokines is shifted towards more cells expressing TNF-alpha and less IL-10+ cells, when compared SLE patients with normal donors. This shift towards proinflammatory memory effector Th cells correlates with disease severity and humoral autoimmunity.

Antibodies, Antinuclear↗
PubMed2006

Submaximal exercise testing in the assessment of interstitial lung disease secondary to systemic sclerosis: reproducibility and correlations of the 6-min walk test.

BACKGROUND: The 6-min walk test (6MWT) is increasingly used as an outcome measure in interstitial lung disease (ILD). AIM: To evaluate the usefulness of the 6MWT in a cohort of patients with ILD secondary to systemic sclerosis (SSc) and to correlate with established physiological parameters. METHODS: 163 patients with SSc-ILD were recruited for a multicentre, randomised, double-blind clinical trial. Available data at protocol screening included repeated 6MWTs, pulmonary function testing with diffusing capacity, Doppler echocardiography and high-resolution computed tomography of the thorax. Borg Dyspnoea Index was evaluated before and after 6MWT. RESULTS: Mean (standard deviation (SD)) distance walked during walk test 1 was 396.6 (84.55) m compared with 399.5 (86.28) m at walk test 2. The within-subject, intertest correlation as determined by Pearson's correlation coefficient testing was 0.95 (p<0.001). However, only weak correlations of 6MWT with percentage forced vital capacity and the Borg Dyspnoea Index were observed, and no correlation was observed with percentage diffusing capacity. CONCLUSION: These data confirm the high reproducibility of the 6MWT in patients with SSc-ILD and therefore the validity of the test in this cohort. The lack of correlation of 6MWT with standard physiological parameters of ILD suggests a multifactorial basis for limited exercise capacity in patients with SSc and calls into question the utility of the 6MWT as a measure of outcome in future studies on SSc-ILD.

Adult↗
PubMed2006

Lack of association between three vascular endothelial growth factor gene polymorphisms and systemic sclerosis: results from a multicenter EUSTAR study of European Caucasian patients.

INTRODUCTION: Systemic sclerosis (SSc) is characterised by disturbed vessel morphology and an overproduction of vascular endothelial growth factor (VEGF). The VEGF gene located on chromosome 6p21.3 has several polymorphisms. OBJECTIVE: To test the hypothesis that disturbed angiogenesis may be related to the genetic background of the VEGF gene. MATERIALS AND METHODS: EUSTAR centres included European Caucasian patients with SSc and matched controls with osteoarthritis. The VEGF gene was genotyped by polymerase chain reaction, followed by restriction enzyme analysis. The 634 C/T and 936 C/G mutations and an 18-base pair insertion/deletion at -2549 of the VEGF promoter region were tested. RESULTS: 416 patients with SSc and 249 controls were included in the study population. Of the patients with SSc, 42% had a diffuse cutaneous subtype, 16% had increased pulmonary arterial pressure and 61% had decreased carbon monoxide diffusion capacity. The genotype frequencies in the patients with SSc and in controls were in Hardy-Weinberg equilibrium. The allele and genotype frequencies of the polymorphisms did not differ between patients with SSc and controls. No association was found between these polymorphisms and disease phenotypes. CONCLUSION: This study shows that there is no association between the three selected functional VEGF polymorphisms and SSc.

Adult↗
PubMed2006

The binding of lupus-derived autoantibodies to the C-terminal peptide (83-119) of the major SmD1 autoantigen can be mediated by double-stranded DNA and nucleosomes.

OBJECTIVES: To evaluate the binding of lupus-derived autoantibodies, double-stranded DNA and nucleosomes to the positively charged C-terminal SmD1(residues 83-119) peptide and the full-length SmD protein. METHODS: The binding of lupus-derived monoclonal antibodies, sera from patients with systemic lupus erythematosus, rheumatoid arthritis and systemic sclerosis, dsDNA and nucleosomes to the SmD1(83-119) peptide or the full-length SmD protein was determined using different ELISA methods. RESULTS: Monoclonal anti-dsDNA antibodies and the serum of patients with systemic lupus erythematosus that are positive for anti-dsDNA antibodies react with the SmD1(83-119) peptide in ELISA. However, DNaseI treatment of the blocking reagents leads to a decreased reactivity. Purified dsDNA and nucleosomes bind to the SmD1 peptide but not to the full-length SmD protein. CONCLUSIONS: The SmD1(83-119) peptide is able to bind dsDNA and nucleosomes, and dsDNA or nucleosomes in applied reagents lead to an apparent reactivity of anti-dsDNA, anti-histone or nucleosome-specific antibodies with the SmD1(83-119) peptide in ELISA.

Animals↗
PubMed2006

[Raynaud phenomenon in dermatology. Part 1: Pathophysiology and diagnostic approach].

Raynaud phenomenon (RP) is characterized by recurrent spasms of small digital arterioles/arteries at fingers and toes, usually triggered by cold and emotional stress. Clinically a sudden pallor of individual digits is followed by reactive hyperemia, in severe cases also by cyanosis. One distinguishes between primary RP, i.e. RP without an underlying disease or drug intake, and secondary RP, which is causally related to an underlying disease or to intake of certain drugs (e.g. interferon, cisplatin). Primary RP is frequent (prevalence of about 13-20% in northern or central Europe), while secondary RP is rare, but the major presenting symptom for systemic sclerosis (SSc). Differential diagnosis includes cold-induced pallor, acute embolic events, paroxysmal hematoma of the finger or erythromelalgia. Vasoconstrictive mechanisms outweigh vasodilatory ones in endothelial cells and vascular smooth muscle. Although soluble mediators such as endothelin or certain prostaglandins have been exploited successfully for therapy, the extent of their involvement in the initial pathophysiology of RP is unclear. Secondary RP (associated with SSc) additionally features morphological alterations with compromise of the vessel lumen. As RP can result in severe discomfort and complications, timely diagnosis and treatment is essential.

Humans↗
PubMed2006

[Raynaud phenomenon in dermatology : Part 2: therapy].

While primary Raynaud phenomenon (RP) only rarely leads to complications, secondary RP when associated with systemic sclerosis (SSc) frequently results in necrosis, ulcers or even gangrene. Therefore timely therapeutic intervention is required. Management of RP includes physical therapy, avoidance of triggers, and a variety of medications, depending on the disease severity. On the basis of published studies and of our own experience we suggest: a) for primary and uncomplicated secondary RP, calcium channel blockers in adequate doses; b) for SSc-associated secondary RP with hypertension, cardial or renal involvement, drugs which interfere with angiotensin; c) in case of concomitant depression, exploitation of the vasodilatory effects of serotonin reuptake inhibitors, d) in presence of ulcers or marked trophic alterations, intravenous administration of iloprost, e) for recalcitrant cases and endangered digits, sildenafil, f) for prevention of severe relapses, the endothelin-receptor antagonist bosentan. The drugs mentioned in c-f are not approved for RP and used off-label. In patients with secondary SSc-associated RP, timely therapy can reduce the percentage of complications such as ulcers or amputations. In addition, timely treatment of RP possibly retards ensuing fibrotic processes.

Humans↗
PubMed2006

Pathophysiology and clinical consequences of Raynaud's phenomenon related to systemic sclerosis.

According to the so-called vascular hypothesis, Raynaud's phenomenon (RP) is one initial event in the pathophysiological cascade leading to sclerosis in systemic sclerosis (SSc). It is characterized by recurrent, reversible spasms of small arterioles and digital arteries, usually triggered by cold and emotional stress. Clinical signs of RP are a sudden pallor of single digits of fingers followed by reactive hyperaemia and in severe cases also by cyanosis. Besides imbalances between vasoconstrictive and vasodilatory processes, structural alterations of the involved vessels are fundamental to secondary RP in SSc. The latter is the reason why secondary RP in SSc, in contrast to primary RP, often leads to ischaemia and re-perfusion injuries. New insights into the pathophysiology of RP feature a special role for alpha2c-adrenoreceptors, Rho-kinase signalling pathways and soluble mediators. They have resulted in promising therapeutic options, including antagonism of endothelin receptors, inhibition of phosphodiesterases or selective blockade of alpha2c-adrenoreceptors. They should also have a positive impact on the course of SSc in general.

Fibrosis↗
PubMed2006

Vasoactive therapies in systemic sclerosis.

In systemic sclerosis (SSc), vasculopathy is a central mechanism and is a major initial event in the process of sclerosis and causing different complications such as Raynaud's phenomenon, ulcer(s) or pulmonary hypertension, the latter being life threatening. Therefore, vasoactive therapies are important when taking care of patients with SSc. However, as treatment has been difficult, numerous therapeutic modalities have been suggested. Until now, the interpretation of most studies is limited due to the heterogeneity of patient groups, the low number of patients, the short duration of the treatments and, possibly, further pathogenic mechanisms such as autoimmunity. Several drugs are now available with effects on vasculopathy and, furthermore, on specific pathogenic mechanisms in SSc. Prostacyclins, endothelin receptor antagonists and phosphodiesterase-5 inhibitors have potential effects on fibrosis, inflammation and endothelial cells, suggesting a disease-modifying capacity in systemic sclerosis. This review summarizes evidence-based therapy recommendations.

Endothelin Receptor Antagonists↗
PubMed2006

Infrared-monitored cold response in the assessment of Raynaud's phenomenon.

BACKGROUND: Evaluation of treatments for Raynaud's phenomenon (RP) requires objective response parameters in addition to clinical activity scores. Thermographic monitoring of fingertip re-warming after cold challenge has been widely used but usually requires sophisticated equipment. We have previously shown that fingertip re-warming after cold challenge follows a first-order transient response curve that can be described by a single variable, designated tau. OBJECTIVES: Here, we describe a novel device termed a duosensor, which records the tau value upon cold challenge in an automated manner. METHODS: We determined tau values in healthy probands, patients with primary or secondary RP associated with autoimmune disease and patients with scleroderma-associated RP following cold challenge, to determine assay variability, sensitivity and specificity. RESULTS: Duosensor-based thermography exhibited low intraindividual variability in healthy probands. As expected, tau values in RP patients were significantly increased compared with controls (8.08 +/- 3.65 min vs. 3.23 +/- 1.65 min). The duosensor-determined tau value yielded a specificity of 94.6% and predictive value of 95.3% for the presence of RP in a retrospective analysis of 139 patients. Furthermore, in a cohort of scleroderma patients with RP, patient self-assessment of RP severity correlated with tau values. CONCLUSIONS: Taken together, the present data suggest that tau value determination provides a suitable outcome measure for clinical studies of novel RP treatments. As the duosensor is a simple stand-alone device requiring no supporting equipment and minimal personnel attention, it should allow RP activity monitoring even in clinical settings with minimal technical infrastructure.

Body Temperature↗