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Biomedical subjects

B M Czarnetzki

Publications and source records attributed to B M Czarnetzki.

At least 19 recordsLinked to original sources
PubMed1992

Topical application of 13-cis-retinoic acid in the treatment of chronic plaque psoriasis.

Topical retinoids are of potential value in the treatment of psoriasis. The aim of the present study was to find out whether topical application of 13-cis-retinoic acid (13-cis-RA) has an antipsoriatic effect. Nine patients participated in the investigation. In each patient, two comparable psoriatic lesions (5 x 5 cm or more) were selected for treatment with either 13-cis-RA in a 0.1% cream base or with the vehicle only (placebo), using a double-blind approach. The investigation was a left-right within-subject comparison. The lesions were recorded for clinical scores 4 weeks before and after the investigation. Punch biopsies were taken from eight patients before and after treatment and examined using immunohistochemical methods to assess epidermal proliferation and keratinization, and to assess inflammation. Thirteen-cis-RA treatment resulted in a mild decrease of scaling and induration. Erythema however increased. No statistically significant difference in biological effects was achieved between 13-cis-RA and placebo treated lesions and no changes in expression of the immunohistochemical markers were seen.

Administration, Topical↗
PubMed1992

Signal transduction pathways in keratinocytes.

Mammalian cells do not live as isolated organisms, but are instead organized into complex, highly specialized tissue organs composed of a homogeneous or a mixed cell population. In order to maintain tissue homeostasis in physiological and pathophysiological conditions, intercellular communication is an absolute requirement. This review will summarize our current knowledge as to how an extracellular signal is transduced via a specific receptor to the interior of the cell and how this signal will induce special cell functions. Attention will be paid to the major signal transduction pathways known to be active in keratinocytes, namely the adenylate cyclase, guanylate cyclase, tyrosine kinase, and phospholipase C systems. Finally, examples will be given of how interactions between these signal transduction pathways can take place and how 'signal cross-talk' might regulate keratinocyte function.

Adenylyl Cyclases↗
PubMed1992

Interferon-alpha therapy in atopic dermatitis.

Thirteen patients with a severe adult form of atopic dermatitis (AD) received 3.0 x 10(6) IU of recombinant interferon-alpha 2a (rIFN-alpha 2a) 3 times a week. A satisfactory response was obtained in 5 of them. Serum IgE levels in all 13 patients remained unchanged throughout the study. Flu-like symptoms were common, but clinical or laboratory adverse effects were otherwise slight. The moderately beneficial therapeutic effects observed in this study support a possible role for IFN-alpha in controlling immunologic deficiencies in atopic dermatitis.

Adolescent↗
PubMed1992

Expression of the high affinity IgE-receptor on human Langerhans' cells. Elucidating the role of epidermal IgE in atopic eczema.

Epidermal Langerhans' cells have previously been shown to bear IgE molecules, particularly in atopic dermatitis skin. Using two highly specific antibodies against the antibody-binding chain of the high affinity IgE-receptor, 29C6 and 6F7, we here provide evidence that Langerhans' cells express this receptor in both normal skin (foreskin) and in lesional skin of patients with atopic and stasis eczema. A specific antibody against the low affinity IgE-receptor, Tü1, showed only a low expression of this receptor. This finding has important potential functional implications for the role of Langerhans' cells in transepidermal, IgE-mediated allergy.

Antibody Affinity↗
PubMed1992

[Ammonium bituminosulfonate (Ichthyol). Anti-inflammatory effect and inhibition of the 5-lipoxygenase enzyme].

Ammonium bituminosulphonate (Ichthyol) inhibits 5-lipoxygenase activity in human polymorphonuclear neutrophils. The inhibition is dose-dependent and occurs at non-cytotoxic concentrations of the drug. This results in a decreased release of Leukotriene B4 from polymorphonuclear neutrophils. Furthermore, when applied to the ear skin of AB/Bln mice pretreated with croton oil, Ichthyol reduces the inflammatory reaction.

Animals↗
PubMed1992

[New perspectives in hair research: in search of the "biological clock" of the hair cycle].

The hair follicle is not only a clinically and commercially important tissue, but can also serve as a fascinating model for studying epithelial-mesenchymal-neuroectodermal interactions. Recently, this has led to a renaissance of hair research, which this speculative review attempts to outline. The unanswered key questions in hair biology are defined before we focus on the crucial search for the "biological clock" that governs the hair cycle. Specifically, we delineate the clinical importance of understanding the mechanisms of catagen induction and propose an immunological mechanism of catagen induction. New research trends are discussed against the background of their potential significance for improving the still frustrating management of hair diseases.

Animals↗
PubMed1991

The effect of topical retinoids on the leukotriene-B4-induced migration of polymorphonuclear leukocytes into human skin.

Systemic retinoids are effective in a variety of inflammatory dermatoses. Disorders in which polymorphonuclear leukocytes (PMN) are involved, such as psoriasis and acne, respond particularly well to various retinoids. However, side-effects restrict the use of systemic retinoids to severe manifestations. Topical application might provide the possibility of avoiding the systemic side-effects of these compounds. In this communication we report on the modulation of transepidermal migration of PMN by topical application of all-trans-retinoic acid, 13-cis-retinoic acid, arotinoid methyl sulphone and arotinoid ethyl sulphone. Test areas of healthy volunteers were pretreated with these retinoids in a cream base and with corresponding placebo creams, and intraepidermal accumulation of PMN was quantified 24 h after epicutaneous challenge with leukotriene B4 (LTB4), using elastase as a marker enzyme. Topical treatment with 13-cis-retinoic acid resulted in a marked and statistically significant inhibition of the LTB4-induced migration of PMN. All-trans-retinoic acid, arotinoid methyl sulphone and arotinoid ethyl sulphone reduced the accumulation of PMN slightly, but not statistically significantly. Topical treatment with arotinoid methyl sulphone had no effect.

Administration, Topical↗
PubMed1991

Topical treatment of multiple actinic keratoses of the face with arotinoid methyl sulfone (Ro 14-9706) cream versus tretinoin cream: a double-blind, comparative study.

In a double-blind, randomized, within-patient comparative study, the efficacy and tolerability of Ro 14-9706 (an arotinoid methyl sulfone) in the treatment of actinic keratoses was compared with that of tretinoin (all-trans-retinoic acid). A total of 25 patients with more than three lesions on each side of the face completed the study. All patients applied each agent twice daily for 16 weeks as a 0.05% cream to opposite sides of the face. The number of actinic keratoses in each treatment area was counted before treatment and at weekly intervals. The mean percent decrease in the number of actinic keratoses was 37.8% for areas treated with Ro 14-9706 and 30.3% for areas treated with tretinoin. Each of these decreases was significantly different from baseline (p less than 0.01), but not from each other. Ro 14-9706 was better tolerated; local inflammation was slight or absent in most patients, whereas tretinoin caused severe erythema in 50% and severe scaling in 23% of patients.

Administration, Cutaneous↗
PubMed1991

In vivo studies of factors influencing mast cell numbers in rat skin.

In order to examine the biological relevance of known in vitro stimuli for mast cell growth, the following substances were injected at two day intervals into the skin of Wistar rats: Ascaris Ag, epidermal growth factor, basic fibroblast growth factor, fibronectin, phytohemagglutinin-stimulated spleen cell supernatants, L-cell fibroblast supernatants and horse serum alone or in combination with L-cell supernatants. In some experiments, rats were also injected with fresh or cultured peritoneal cells. Single injections of the different factors had no significant effect on mast cell numbers. After multiple injections (4-10 x), deep dermal and submuscular mast cell numbers increased most markedly in ascaris sensitized animals at sites of ascaris antigen injections and in normal animals in response to a combination of horse serum and L-cell supernatants. Less pronounced increases occurred with all other test substances except for epidermal growth factor which was inactive. Mast cell numbers were also increased at sites of injections of immature, cultured mast cells and less so after injections of mast cell precursors and mature cells. Taken together, these data show that in vivo growth and differentiation of cutaneous mast cells can be influenced by several fibroblast- and lymphocyte-derived growth factors.

Animals↗
PubMed1991

Detection of human papillomaviruses in paraffin-embedded condylomata acuminata--comparison of immunohistochemistry, in situ hybridization, and polymerase chain reaction.

The polymerase chain reaction (PCR) is used for detection of human papillomavirus (HPV) DNA in paraffin-embedded tissue sections of condylomata acuminata. Incorporation of biotinylated nucleotides during the amplification process allows a highly sensitive, fast, and non-isotopic detection of viral DNA in a subsequent Southern dot blot. In 100% (13 of 13) of histologically confirmed condylomata, HPV-6 or -11 could be detected by polymerase chain reaction. By in situ hybridization 77% (10 of 13) and by immunohistochemistry (IHC) 69% (nine of 13) positive results were obtained. Because HPV genital infection is linked to penile and cervical dysplasia, polymerase chain reaction provides a powerful and highly sensitive tool for epidemiologic studies on sexual transmission of HPV.

Adult↗
PubMed1991

Gene amplification by polymerase chain reaction in dermatology.

The polymerase chain reaction (PCR) is another new powerful technique in molecular biology that has begun to open new perspectives in modern science and also in dermatology. This brief report will therefore elucidate the general principles of the polymerase chain reaction, as well as its limitations and possible pitfalls. Furthermore an overview will be provided on the impact of PCR on molecular biologic approaches in oncology, immunology, and human genetics. The use of the method as a tool to detect microorganisms particularly viruses and bacteria, in cutaneous tissue and it potential other future applications are described as well. Because PCR is automated and is being more and more established in routine laboratories, physicians and scientists should be familiar with the basic principles and potential uses of this methodology.

Gene Amplification↗
PubMed1991

In vitro generation of smooth muscle-contracting leukotrienes from isolated epidermal cells.

Single-cell suspensions of murine and human epidermal cells were studied for the presence of peptidoleukotrienes (LTs), using in vitro guinea pig ileum contraction as bioassay and a commercial radioimmunoassay. The calcium ionophore A23187 at 5 x 10(-6) M alone or in combination with arachidonic acid at 10(-4) M caused release of LTC4/D4 within 10-30 min and for up to 18 h. LTB4, as was measured in the chemotaxis assay, was released at different levels and with different kinetics from the same cells. Epidermal cells may thus regulate cutaneous inflammation by secreting potent vasoactive and muscle-contracting in addition to chemotactic lipid mediators.

Animals↗
PubMed1991

Mast cells and their mediators in immediate and delayed immune reactions.

Tissue mast cells and the closely related blood basophils are distinguished by their special mediators and their high-affinity IgE membrane receptors. These properties have made the cells be viewed traditionally as effector cells of immediate-type hypersensitivity reactions. More recently, mast cells have been shown to develop from the myeloid series of the bone marrow under the influence of interleukins 3, 4, 6, 9, 10 and 11. Mast cell and basophil lines of murine and human origin have also been shown to express and release interleukins 1, 3, 4, 5, 6, 8, tumor necrosis factor-alpha, granulocyte-macrophage colony-stimulizing factor and interferon-gamma. Certain cytokines are also able to induce mediator release from mast cells. Furthermore, mast cells have in the past been shown to be modestly phagocytic and to express major histocompatibility complex class II membrane markers after appropriate stimulation. These findings show that mast cells are intricately associated with immune reactions and suggest that they may not only sustain and modulate but possibly also initiate immune responses.

Animals↗