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Biomedical subjects

R J Ludwig

Publications and source records attributed to R J Ludwig.

7 recordsLinked to original sources
PubMed2007

Psoriasis: a possible risk factor for development of coronary artery calcification.

BACKGROUND: Psoriasis is a chronic inflammatory skin disorder affecting about 2% of white-skinned individuals. Epidemiological data on the prevalence and degree of coronary artery calcification (CAC) as an indicator for cardiovascular diseases in patients with psoriasis are contradictory. OBJECTIVES: To study the prevalence and degree of CAC as an indicator for cardiovascular diseases in 32 patients with psoriasis matched for age, sex and risk factors to an equally sized control population. METHODS: Noncontrast-enhanced 16-row spiral computed tomography was performed in patients and controls. RESULTS: We found a significantly increased prevalence (59.4% vs. 28.1%, P = 0.015) and severity (CAC score according to Agatston 3.7 vs. 0.0, P = 0.019) of CAC in patients with psoriasis. Multiple linear regression calculations identified psoriasis as a likely independent risk factor for CAC. CONCLUSIONS: Our results point towards the potentially systemic nature of the inflammatory processes underlying the pathogenesis of psoriasis, which may therefore be considered a potentially severe systemic disease.

Adult↗
PubMed2006

Chronic venous insufficiency - a potential trigger for localized scleroderma.

Localized scleroderma is a cutaneous disease that is characterized by an initial inflammatory response, followed by sclerosis of the skin. The cause of localized scleroderma has not yet been determined. Seifarth et al. reported two cases of localized scleroderma at sites of chronic venous insufficiency. We document here three more patients in whom localized scleroderma was located at insufficient veins. Treatment of underlying chronic venous insufficiency (CVI) leads to a substantial clinical improvement of scleroderma at the site of insufficient veins, but not elsewhere. Experimental data support the concept of chronic venous insufficiency creating a microenvironment, which may lead to localized scleroderma. Local hypoxaemia, which is present in CVI, induces the release of endothelium-derived cytokines, such as IL-1. Subsequently, expression of endothelial adhesion molecules and consequently leucocyte extravasation are induced. Infiltrating leucocytes secrete a number of inflammatory mediators, including transforming growth factor beta, which is a potent stimulus for collagen synthesis. Therefore, it may well be that CVI is a potential trigger factor for localized scleroderma. In addition, localized scleroderma may only develop if a certain amount of trigger factors are present - and resolves if one or more of the contributing factors (i.e. CVI) can be treated.

Adult↗
PubMed2004

Secretin: hypothalamic distribution and hypothesized neuroregulatory role in autism.

1. This study aims (1) to determine whether secretin is synthesized centrally, specifically by the HPA axis and (2) to discuss, on the basis of the findings in this and previous studies, secretin's possible neuroregulatory role in autism. 2. An immunocytochemical technique with single-cell resolution was performed in 12 age/weight-matched male rats pretreated with stereotaxic microinjection of colchicine (0.6 microg/kg) or vehicle into the lateral ventricle. Following 2-day survival, rats were anesthetized and perfused for immunocytochemistry. Brain segments were blocked and alternate frozen 30-microm sections incubated in rabbit antibodies against secretin, vasoactive intestinal peptide, glucagon, or pituitary-adenylate-cyclase-activating peptide. Adjacent sections were processed for Nissl stain. Preadsorption studies were performed with members of the secretin peptide family to demonstrate primary antibody specificity. 3. Specificity of secretin immunoreactivity (ir) was verified by clear-cut preadsorption control data and relatively high concentrations and distinct topographic localization of secretin ir to paraventricular/supraoptic and intercalated hypothalamic nuclei. Secretin levels were upregulated by colchicine, an exemplar of homeostatic stressors, as compared with low constitutive expression in untreated rats. 4. This study provides the first direct immunocytochemical demonstration of secretinergic immunoreactivity in the forebrain and offers evidence that the hypothalamus, like the gut, is capable of synthesizing secretin. Secretin's dual expression by gut and brain secretin cells, as well as its overlapping central distribution with other stress-adaptation neurohormones, especially oxytocin, indicates that it is stress-sensitive. A neuroregulatory relationship between the peripheral and central stress response systems is suggested, as is a dual role for secretin in conditioning both of those stress-adaptation systems. Colchicine-induced upregulation of secretin indicates that secretin may be synthesized on demand in response to stress, a possible mechanism of action that may underlie secretin's role in autism.

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