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Biomedical subjects

W Vanscheidt

Publications and source records attributed to W Vanscheidt.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Computerized tomography and magnetic resonance tomography studies before and after para-tibial fasciotomy].

Paratibial fasciotomy has been employed since 1981 to treat patients with chronic venous insufficiency (CVI) and therapy-resistant leg ulcers with severe lipodermatosclerosis. The characteristic morphological changes in CVI were evaluated shown before and after paratibial fasciotomy using computerized tomography (CT) and magnet resonance tomography (MRT). 10 patients (6 female, 4 male) were examined by CT and MRT pre- and postoperatively. Preoperatively there is a clear thickening of the dermis and subcutaneous field. In addition, the area around the achilles tendon is thickened, the fasciae are enlarged and the muscles of the lower leg show an increase of fatty tissue. A decrease of the cutaneous and subcutaneous thickening is seen postoperatively. The fasciotomy split is visible in most patients.

Adipose Tissue↗
PubMed1996

[Bath additives in dermatologic balneotherapy. Indications and approaches in current research].

Progress in dermatological research during the last years has provided new insights into the mode of action of additives to dermatological baths. The present paper reviews the pharmacokinetics of dermatological bath therapy additives such as sulfur, salts and trace elements, tars and ichthyol, lipids, antiseptics, astringents, plant extracts, surface-active agents and proteins.

Balneology↗
PubMed1996

Expression of the adhesion molecules ICAM-1, VCAM-1, and E-selectin and their ligands VLA-4 and LFA-1 in chronic venous leg ulcers.

BACKGROUND: Leukocyte binding to endothelial cells (ECs) is thought to contribute to the pathogenesis of leg ulcers caused by chronic venous insufficiency. In other systems, such binding is mediated by the interaction of adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule- (VCAM-1) and E-selectin (on ECs), and leukocyte function-associated antigen-1(LFA-1) and very late activated antigen-4 (VLA-4) (on Leukocytes). OBJECTIVE: Our purpose was to determine whether an increased expression of these adhesion molecules contributes to the pathogenesis of chronic venous insufficiency. METHODS: Twenty-seven biopsy specimens of inflamed dermatoliposclerotic skin adjacent to venous leg ulcers were stained immunohistochemically with monoclonal antibodies against ICAM-1, VCAM-1, LFA-1, VLA-4, and E-selectin. Staining intensity was compared with that of normal skin. RESULTS: Specimens of leg ulcers caused by chronic venous insufficiency showed increased expression of ICAM-1 and VCAM-1 but not of E-selectin on The expression of LFA-1 and VLA-4 on perivascular leukocytes was increased dramatically in comparison to healthy skin. CONCLUSION: Upregulation of ICAM-1 and VCAM-1 on ECs may contribute to the increased adherence and extravasation of LFA-1 and VLA-4-positive leukocytes in chronic venous insufficiency.

Aged↗
PubMed1996

Clinical histochemical and immunohistochemical investigation of the capillary basal membrane in chronic venous insufficiency.

Present investigations regarding the pathogenesis of chronic venous insufficiency (CVI) are focusing on microvascular changes. The aim of our investigation was to examine the correlation between the thickness of pericapillary type IV collagen depositions, basal membrane alterations and transcutaneous oxygen tension (TcPO2) in CVI-patients. Histochemical and immunohistochemical investigation of the capillary basal membrane was performed on 15 biopsies from normal controls, as well as 30 patients with CVI stage I and III (classification by Widmer & Stähelin). In all subjects TcPO2 was measured just prior to biopsy procedures in exactly the same area where the specimen was subsequently excised. The microscopically measured thickness of the collagen IV layer and the basal membrane was increased significantly in patients with CVI. Specimens from normal controls showed a collagen IV layer thinner than 0.1 micron. Patients with CVI stage III revealed strong collagen IV depositions between 0.2 and 0.3 microns. Comparison between TcPO2 and histological findings in the measured ares showed oxygen pressure varying from 62 mmHg (SEM 4.94 mmHg) in normal controls, down to 13 mmHg (SEM 3.39 mmHg) in patients with thick collagen IV layers. Besides an increased collagen IV layer, microvascular thrombosis and a thickened basal membrane have to be considered for impaired capillary perfusion.

Adult↗
PubMed1995

[Malignant melanoma of the skin].

The incidence of malignant melanoma (MM) of the skin is on the increase. If the mortality of this disease is to be reduced, the identification of persons at risk, and early clinical diagnosis are of decisive importance. The prognosis depends on the stage of the disease and has improved over the last few decades. The present article provides an overview of the risk factors and discusses the latest guidelines for the diagnosis, treatment and follow-up, the aim of which is to make possible a uniform approach to the management of malignant melanoma.

Combined Modality Therapy↗
PubMed1995

In situ expression of B7 and CD28 receptor families in human malignant melanoma: relevance for T-cell-mediated anti-tumor immunity.

Work in animal models has suggested that interactions of members of the B7 receptor family (e.g., B7-1, B7-2) on tumor cells with their ligands CD28 and CTLA-4 on cytotoxic T cells (CTL) are important for the induction of anti-tumor immunity against malignant melanoma (MM). To determine whether these molecules are of relevance for CTL responses against human MM, we studied the expression of B7-1, B7-2, CD28 and CTLA-4 in primary tumors of MM (PMM), MM metastases (MMM) and benign melanocytic nevi (BMN) by immunohistochemistry (IH) and by reverse transcription polymerase chain reaction (RT-PCR). By RT-PCR, B7-1 and B7-2-specific mRNAs were detected in most PMM, MMM and BMN. These PCR-signals were derived from CD45(+)-infiltrating leukocytes and not from tumor cells since (I) MMM depleted of CD45+ cells contained no B7-1 or B7-2 mRNA; and (2) by IH, B7-1 and B7-2 were found on infiltrating dendritic cells, macrophages and a variable proportion of tumor-infiltrating lymphocytes (TIL) but not on melanoma cells or nevus cells. The important exceptions were 5/5 spontaneously regressing PMM, in which B7-1 and B7-2 were expressed by melanoma cells, that were surrounded by TIL expressing CD28 but not CTLA-4. We conclude that, in PMM, MMM and BMN, the majority of TIL are CD28+ and that B7-1 and B7-2 are expressed by CD45(+)-infiltrating antigen-presenting cells (APC) and TIL, but not by the tumor cells. However, in spontaneously regressing PMM, melanoma cells express B7-1, B7-2 and MHC class-I and -II antigens, particularly in areas with clinical and histological signs of an ongoing anti-tumor response. These data suggest that the absence of B7-1 and B7-2 favors the escape of MM from immunosurveillance, while B7-1, B7-2 expression enhances T-cell-mediated anti-tumor immunity.

Abatacept↗
PubMed1995

[Treatment of naevi flammei in adulthood with a flashlamp pumped pulsed dye laser].

Since 1993 almost 400 patients with port wine stains have been treated with the flashlamp pumped pulsed dye laser. The therapeutic effect on 61 adult patients was evaluated. After a mean of 2.16 treatments the colour lightened by between 33% and 100% in 70% of these patients. The best results were obtained in patients with plain pink port wine stains. In this kind of port wine stains the argon laser has proved to be far less successful. The rate of adverse effects amounted to only 5%. The results are expected to be improved by further laser sessions. The flashlamp pumped pulsed dye laser is an important advance in the treatment of port wine stains.

Adolescent↗
PubMed1995

Pentoxifylline inhibits tumor necrosis factor-alpha (TNF alpha)-induced T-lymphoma cell adhesion to endothelioma cells.

Pentoxifylline, a methylxanthine derivative, has been shown to inhibit T-cell-mediated cutaneous immune response by yet ill-understood mechanisms. Because cell adhesion to endothelial cells is a critical step in the initiation of such immune responses, we analyzed whether pentoxifylline would affect this process. To address this issue, adhesion of mouse T-lymphoma cells (TK-1) to mouse endothelioma cells (eEnd.2), either untreated or stimulated with tumor necrosis factor-alpha (TNF alpha), was studied. Pentoxifylline reduced the ability of endothelioma cells stimulated with different concentrations of TNF alpha, but not of untreated endothelioma cells, to bind T-lymphoma cells in dose-dependent (10(-5)-10(-3) M) fashion. Selective incubation of either endothelioma cells or T-lymphoma cells revealed that pentoxifylline acted exclusively on the endothelioma cells, even when added after TNF alpha stimulation. We questioned whether pentoxifylline suppressed T-lymphoma cell/endothelioma cell interactions by interfering with adhesion molecules expressed by either cell. However, as determined by flow cytometry, pentoxifylline did not alter TNF alpha-induced upregulation of intercellular adhesion molecule-1 or vascular cellular adhesion molecule-1 on endothelioma cells nor did it affect constitutive CD11a, CD18, or alpha 4-integrin expression on T-lymphoma cells, suggesting that rather than affecting quantitative expression of these adhesion molecules, pentoxifylline might modulate their avidity. We conclude that pentoxifylline in therapeutically achievable concentrations is a potent inhibitor of TNF alpha-induced T-lymphoma cell adhesion to endothelioma cells. This finding may account, at least in part, for the recently discovered anti-inflammatory action of pentoxifylline.

Animals↗
PubMed1995

Prostaglandin E1 inhibits TNF alpha-induced T-cell adhesion to endothelial cells by selective down-modulation of ICAM-1 expression on endothelial cells.

Prostaglandins have been shown to be involved in the suppression of contact hypersensitivity (CHS) by so-far ill understood mechanisms. T-cell migration across the lining of cytokine-activated endothelial cells (EC) is thought to be a central step in the initiation of CHS. The aim of our investigation was therefore to examine whether prostaglandin E1 (PGE1) influences cytokine-induced TK-1 mouse T-cell lymphoma adhesion to eEnd.2 mouse endothelioma cells. Here, we report that PGE1 (10(-12)-10(-8) M) dose-dependently reduced TNF alpha-induced T-cell binding, while TNF alpha-unstimulated adhesion was not affected. To test whether PGE1 acted primarily on T-cells or on EC, they were separately pretreated with PGE1 prior to the adhesion assay. Selective PGE1 pretreatment of eEnd.2, but not of TK-1 dose-dependently inhibited TNF alpha, stimulated T-cell adhesion. Since binding of TK-1 to TNF alpha-treated eEnd.2 is mediated by the interaction of ICAM-1 and VCAM-1 (on EC) with their receptors LFA-1 and VLA-4 (on T-cells), we further investigated whether PGE1 would modulate the expression of these molecules. FACS-analysis revealed PGE1 to inhibit TNF alpha-induced upregulation of ICAM-1, but not of VCAM-1 on EC. Furthermore, constitutive LFA-1 and VLA-4 expression on T-cells was not affected by PGE1. We conclude that PGE1 supresses T-cell adhesion to EC by selectively inhibiting TNF alpha-induced upregulation of ICAM-1 on EC. This may be one mechanism by which prostaglandins suppress immune responses requiring T-cell EC interactions such as contact hypersensitivity in skin.

Alprostadil↗
PubMed1994

Expression of the B7/BB1 activation antigen and its ligand CD28 in T-cell-mediated skin diseases.

Interactions of CD28 (on T cells) with its recently identified ligand B7/BB1 (on antigen-presenting cells) have been shown to activate T cells via a major histocompatibility complex/Ag-independent "alternative" pathway, leading to an amplification of T-cell-mediated immune responses. The in vivo relevance of these molecules for cutaneous immunity is presently unknown. These findings prompted us to study the expression of B7/BB1 and CD28 in normal human skin and in selected T-cell-mediated inflammatory skin diseases. Biopsies were obtained from lesional skin of patients with allergic contact dermatitis, lichen planus, and, as control, from basal cell carcinoma and from healthy controls. Serial cryostat sections were stained with a panel of MoAbs directed against CD28, B7/BB1, CD3, CD1a, and KiM8 using immunohistochemistry (ABC technique). CD28 expression was observed in the majority of dermal and epidermal CD3+ T cells in contact dermatitis and lichen planus. In normal skin and basal cell carcinoma, CD28 was expressed only occasionally by perivascular T cells. In allergic contact dermatitis and lichen planus, B7/BB1-expression was found on dermal dendritic cells, on dermal macrophages, on Langerhans cells, focally on keratinocytes, and occasionally on dermal T cells. No B7/BB1 immunoreactivity was detected in normal skin and basal cell carcinoma. These findings indicate that T-cell-mediated skin diseases are accompanied by an influx of CD28+ T cells and an upregulation of B7/BB1 on cutaneous antigen-presenting cells, keratinocytes, and on some T cells. We speculate that "alternative" T cell-activation via the B7/CD28 pathway may contribute to the pathogenesis of these skin diseases.

Antibodies, Monoclonal↗
PubMed1993

The importance of the subfascial lymphatics in the diagnosis of lower limb edema: investigations with semiquantitative lymphoscintigraphy.

A new method of semiquantitative lymphoscintigraphy for the evaluation of lower limb edema is characterized by (1) the evaluation of both the epifascial and subfascial system in order to assess type and stage of the edema, (2) the use of high-resolution digital whole-body imaging to facilitate the calculation of functional parameters, and (3) the use of active, standardized ergometry for reproducibility. The appearance time of 99mTc-labeled human albumin nanocolloid in inguinal lymph nodes after injection and the percent uptake of colloid into lymph nodes at 40 and 120 min after injection served as functional parameters. Patients with edema of the lower limb were compared with normal subjects. In patients with primary lymphedema the two lymphatic compartments are functionally compromised. Early and advanced stages of postthrombotic syndromes can be distinguished by characteristic lymphoscintigraphic patterns in epifascial and subfascial lymphatic compartments. These results indicate that only the separate evaluation of both the epifascial and subfascial compartments allows an accurate functional assessment of the lymphatics in lower limb edema.

Adolescent↗
PubMed1991

Immunohistochemical investigation of dermal capillaries in chronic venous insufficiency.

Skin biopsies from the area of the medial malleolus of 24 patients with chronic venous insufficiency, of 5 patients without signs or history of chronic venous insufficiency and of seven corpses without manifestation of chronic venous insufficiency, were sectioned and stained with hematoxylin and eosin and with Ki-67, a monoclonal antibody expressed in the nuclei of proliferating cells. Hematoxylin- and eosin-stained sections of all specimens were assessed blindly to determine the state of capillary increase in stasis dermatosis. Twenty-four patients were found to have different stages of stasis dermatosis. During the examination of the Ki-67 frozen sections, close attention was paid to the capillary bed of all sections for any Ki-67-positive nuclei in capillary cells. None of the three groups showed positive staining of nuclei in capillary cells. This finding proves that there is no capillary proliferation, but an elongation and distension of the capillaries.

Adult↗
PubMed1991

Factor XIII-deficiency in the blood of venous leg ulcer patients.

Pericapillary fibrin cuffs are probably involved in the pathogenesis of venous leg ulcers. Factor XIII (Fibrin stabilizing factor) is of importance in wound healing. Its activity, which may affect ulceration, was found to be significantly reduced in the blood of venous leg ulcer patients and in post-phlebitic patients, compared with healthy controls.

Chronic Disease↗
PubMed1991

Paratibial fasciotomy.

Paratibial fasciotomy is a new surgical approach to conservatively therapy-resistant venous leg ulcers. Its technique and preliminary results are reported. It is concluded hypothetically that the fasciotomy splitting itself plays the main role for its therapeutical success.

Bandages↗
PubMed1991

[Peri-capillary fibrin cuffs--an O2 diffusion block?].

In 42 patients with a chronic venous insufficiency Stage I-III transcutaneous oxygen tension was measured above the medial ankle and the leg ulcer edges respectively at 44 degrees C. The measurement point was biopsied and evaluated immunfluorescencehistologically for pericapillary fibrin cuffs (PCF). Fibrin cuffs are associated with decreased tcpO2-tensions. All PCF-positive biopsies were from areas with a tcpO2 less than 35 mmHg. The difference of PCF-positive and PCF-negative biopsies concerning the mean tcpO2 was significant (Wilcoxon-U-Test; p less than 0.001). The evidence of pericapillary fibrin cuffs associated with tcpO2 tensions up to 33 mmHg proves that this phenomenon alone cannot be a diffusion barrier.

Adult↗