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Biomedical subjects

H C Korting

Publications and source records attributed to H C Korting.

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

Coal tar, pine tar and sulfonated shale oil preparations: comparative activity, efficacy and safety.

BACKGROUND: Tar and sulfonated shale oil preparations are used in the treatment of a variety of inflammatory skin diseases, including psoriasis vulgaris; due to the high polycyclic aromatic hydrocarbon (PAH) content of tars, a possible relationship with cancer in humans has been postulated. On the other hand, the purity of sulfonated shale oils concerning PAHs guarantees a good tolerability during dermatologic therapy. AIM: In this review, it is attempted to compare activity, efficacy and safety of coal tar, pine tar and sulfonated shale oil preparations which currently play a role in dermatologic treatment. RESULTS AND CONCLUSIONS: Primary sources of PAHs in the normal human environment are forest fires, cigarette smoke and combustion of fossil fuels for heating and energy. Thermal processing of fossil substances is also required for the production of tars and sulfonated shale oils. Due to individual manufacturing techniques, tars and sulfonated shale oils differ completely in their chemical composition. Still, sulfonated shale oils are often falsely grouped as tars because of their related origin and similar dermatologic indications. There is at least limited evidence of the activity and efficacy of various tars as well as sulfonated shale oil preparations in different frequent inflammatory skin diseases. This includes psoriasis vulgaris and atopic eczema of glabrous as well as hairy skin. There is still some concern about the long-term tolerability of tar preparations at least in some contexts. This, however, does not apply to sulfonated shale oil preparations. Consequently, at least their use should still be considered a rational drug treatment in dermatology.

Animals↗
PubMed1996

The hyperkeratotic variant of porokeratosis Mibelli is a distinct entity: clinical and ultrastructural evidence.

An isolated case with the hyperkeratotic variant of porokeratosis Mibelli (PM) is reported. The 62-year-old woman developed multiple brown macules with well demarcated large keratotic nodules on both legs. Histopathological studies revealed the presence of a cornoid lamella characteristic of porokeratosis. Ultrastructural investigations revealed dyskeratotic as well as edematous, swollen keratinocytes; autophagocytotic vacuoles were visible. The clinical and ultrastructural peculiarities of the hyperkeratotic variant of PM suggest the possibility of a separate entity.

Administration, Topical↗
PubMed1996

Topical glucocorticoids with improved risk-benefit ratio. Rationale of a new concept.

Topical glucocorticoids for dermal application were introduced more than 40 years ago and revolutionised the treatment of inflammatory skin diseases. Today these drugs are frequently administered, although systemic and local adverse drug reactions, especially skin atrophy, are feared complications of their use. This literature review evaluates the present state of topical glucocorticoid therapy for inflammatory skin diseases. Several attempts have been made to increase the safety of topical glucocorticoid treatment. With respect to conventional compounds, new application schedules, as well as new vehicles, have been proposed. New derivatives have also been synthesized, forming the novel group of nonhalogenated double-ester-type glucocorticoids. Among these latter compounds, prednicarbate and 6-methyl-prednisolone aceponate have been characterised most thoroughly. According to in vivo studies, their anti-inflammatory activity is in the order of that of betamethasone valerate (a frequently used medium potency glucocorticoid, which is obtained by halogenation of the pregnane nucleus of the steroid molecule). Furthermore, these new congeners induce less skin atrophy than conventional glucocorticoids, as determined by in vivo and in vitro studies. Qualitative and quantitative assessment of the therapeutic and adverse effects of non-halogenated double-ester-type glucocorticoids suggests an increased benefit-to-risk ratio.

Administration, Topical↗
PubMed1996

Multiple keratoacanthomas, giant keratoacanthoma and keratoacanthoma centrifugum marginatum: development in a single patient and treatment with oral isotretinoin.

A 78-year-old man is described, who over 18 years developed three different types of keratoacanthoma: multiple keratoacanthomas, keratoacanthoma centrifugum marginatum and giant keratoacanthoma. Histological examination of the different neoplasms showed similar changes, all typical of a keratoacanthoma. In situ hybridisation revealed no human papilloma virus in the tumours. Complete examination showed no associated internal malignancy. After repeated surgical treatment oral isotretinoin treatment was administered (1 mg/kg per day). This treatment produced clearing of existing keratoacanthomas and, during a period of 2 months, further keratoacanthoma formation was completely suppressed. Treatment was stopped after 3 months by the patient because of side-effects. Numerous keratoacanthomas developed during the following 6 weeks.

Administration, Oral↗
PubMed1996

[The treatment of cutaneous radiation-induced fibrosis with pentoxifylline and vitamin E. An empirical report].

BACKGROUND: Radiation fibrosis represents a severe complication of radiation therapy; standardized treatment protocols are lacking so far. Surgical excision rarely results in complete healing. PATIENT AND METHODS: We report on a 58-year-old female patient who developed a squamous cell carcinoma within the fibrotic area of the irradiation field on the right chest, resulting from a radiotherapy following mastectomy for breast cancer 17 years ago. After surgical excision of the carcinoma a combined treatment with pentoxifylline tablets (3 x 400 mg/d p.o.) and vitamin-E capsules (1 x 400 mg/d p.o.) was initiated. Skin thickness was quantified by 20 MHz-ultrasound before and during treatment. RESULTS: The patient noted an increasing improvement of the condition of the affected skin starting from 4 months. A continuing decrease of skin thickness as documented by 20 MHz-ultrasound could be demonstrated from the 6th month on. The treatment was tolerated well, no side effects were observed. CONCLUSION: The data indicate a beneficial therapeutic effect of pentoxifylline and vitamin E on radiation-induced fibrosis. Little is known about the mechanism of action of this combined treatment protocol including pentoxifylline and vitamin E. Controlled clinical trials should be performed to confirm this observation.

Breast Neoplasms↗
PubMed1996

Interaction of cultured human keratinocytes with liposomes encapsulating silver sulphadiazine: proof of the uptake of intact vesicles.

There is evidence to suggest that human keratinocytes grown in vitro are capable of engulfing and subsequently disintegrating intact liposomes. However, as the liposomes used in this context did not carry an electron-dense marker, the possibility that the lamellar structures seen within the keratinocytes were composed of material produced within the cell could not be excluded. We therefore decided to investigate liposome-keratinocyte interaction using an electron-dense marker. Human keratinocytes obtained from juvenile foreskins were cultured in a serum-free medium, and subconfluent cultures were exposed to liposomally encapsulated and free silver sulphadiazine 1% (SSD), and a corresponding vehicle, for 5 min to 24 h. After fixation ultra-thin sections were analysed electron microscopically at magnifications of up to x85,000. Many keratinocytes treated with liposomal and free SSD showed marked damage to the plasma membranes and the cell organelles. The phagocytosis of intact liposomes was demonstrated by the appearance of silver-labelled unilamellar vesicles within the cytoplasm of undamaged keratinocytes. The labelled liposomes were found enclosed in cellular unit membranes, i.e. in lysosomes. In addition, perinuclear disintegration and release of the entrapped marker were observed. Silver particles, as present in liposomally encapsulated SSD, were found to be adequate markers for electron microscopy. Our results confirm the phagocytosis of intact liposomes by keratinocytes in vitro. In addition, the cytotoxic effects of liposomal (intended for the treatment of burns) and free SSD on human keratinocytes were studied in detail. Many keratinocytes treated for 10 min or more were severely affected.

Cells, Cultured↗
PubMed1995

Assessment of cutaneous and ocular irritancy: a decade of research on alternatives to animal experimentation.

Over the past decade increasing societal and scientific pressure has promoted the development of alternatives to local tolerance testing in laboratory animals. The use of isolated organs, fertilized hen's eggs, and cell culture systems has been proposed as well as the study of a toxicant's biochemical effects and structure-activity relationships. This paper critically reviews the current status of these approaches and discusses the preliminaries for the establishment of alternative methods in the process of safety assessment.

Animal Testing Alternatives↗
PubMed1995

Comparative efficacy of hamamelis distillate and hydrocortisone cream in atopic eczema.

In a double-blind, randomized, paired trial lasting 14 days in 72 patients with moderately severe atopic eczema, hamamelis distillate cream (5.35 g hamamelis distillate with 0.64 mg ketone/100 g) was compared with the corresponding drug-free vehicle and 0.5% hydrocortisone cream, and reductions of the basic criteria of severe atopic eczema (delta values of the sum scores), i.e. itching, erythema and scaling, were evaluated. Thirty-six patients in each group were treated, which allowed the detection of a 10% difference between verum and control (confirmatory study). Effects were compared using Wilcoxon's test. The mean sum scores of the basic criteria of the test areas were 5.3-5.5. All treatment regimens significantly reduced itching, erythema and scaling after 1 week. Hydrocortisone proved superior to hamamelis distillate. The basic criteria scores decreased by 2.7 and 1.6, respectively. The delta values of the minor criteria and the global rating of efficacy were also used to indicate the difference between these preparations. Hamamelis distillate cream, however, did not differ from the vehicle. Mean delta values of basic criteria were 1.8 and 2.0, respectively. All preparations were well tolerated. Unwanted cutaneous reactions occurred in six patients, although due to their inflammatory nature and their confinement to vehicle-treated patients, they may not represent true adverse effects but rather a lack of efficacy. The results prove the superiority of low-dose hydrocortisone cream over hamamelis distillate cream, and the therapeutic outcome following this preparation was no better than following the base preparation. The mild, yet unmistakable anti-inflammatory effect of hamamelis cream in experimental models of inflammatory skin disease was thus not reflected by an efficacy in patients with atopic eczema greater than that obtained from the base preparation.

Administration, Topical↗
PubMed1995

Molecular evidence for the existence of disseminated zoster as a distinct entity in an immunosuppressed renal transplant patient.

Immunosuppressed renal transplant recipient are at substantially increased risk for the development of varicella zoster virus infections. They are also more prone than immunocompetent patients to develop atypical zoster and to experience a protracted course, and among them there is a higher frequency of generalized infections with possible fatal outcome. While establishing the diagnosis is essential to provide adequate therapy, conventional laboratory methods frequently fail to confirm the suspected infection. We report on a 47-year-old renal transplant recipient who developed multiple necrotic cutaneous ulcers under immunosuppressive treatment. While electron-microscopic analysis (negative staining) revealed no viral structures, varicella zoster virus specific DNA was detected by polymerase chain reaction in material obtained by a swab from these ulcers. Atypical herpetic infection should also be considered as a cause of disseminated ulcerative or necrotic skin lesions in immunosuppressed patients. Assays based on polymerase chain reaction are useful for the rapid confirmation or rejection of the suspected diagnosis of atypical herpetic infection.

Base Sequence↗
PubMed1995

The role of vitamin E in normal and damaged skin.

The generation of free oxygen radicals is believed to play an important pathogenic role in the development of various disorders. More than other tissues, the skin is exposed to numerous environmental chemical and physical agents such as ultraviolet light causing oxidative stress. In the skin this results in several short- and long-term adverse effects such as erythema, edema, skin thickening, wrinkling, and an increased incidence of skin cancer or precursor lesions. However, accelerated cutaneous aging under the influence of ultraviolet light, usually termed photoaging, is only one of the harmful effects of continual oxygen radical production in the skin. Others include cutaneous inflammation, autoimmunological processes, keratinization disturbances, and vasculitis. Vitamin E is the major naturally occurring lipid-soluble non-enzymatic antioxidant protecting skin from the adverse effects of oxidative stress including photoaging. Its chemistry and its physiological function as a major antioxidative and anti-inflammatory agent, in particular with respect to its photoprotective, antiphotoaging properties, are described by summarizing animal studies, in vivo tests on human skin and biochemical in vitro investigations. The possible therapeutic use in different cutaneous disorders, and pharmacological and toxicological aspects are discussed. Many studies document that vitamin E occupies a central position as a highly efficient antioxidant, thereby providing possibilities to decrease the frequency and severity of pathological events in the skin. For this purpose increased efforts in developing appropriate systemic and local pharmacological preparations of vitamin E are required.

Animals↗
PubMed1995

Discrimination of the toxic potential of chemically differing topical glucocorticoids using a neutral red release assay with human keratinocytes and fibroblasts.

In inflammatory skin disease, hydrocortisone and prednisolone double esters are about equipotent to conventional medium potency topical glucocorticoids, such as betamethasone valerate. Local adverse effects, in particular skin atrophy, are a potential problem with topical glucocorticoids. Recently, cell cultures have shown promise as a means of assessing local tolerance. To investigate the toxic potential of hydrocortisone, hydrocortisone-17-butyrate, hydrocortisone aceponate, prednicarbate, triamcinolone acetonide, betamethasone valerate and desoximethasone, human keratinocytes and fibroblasts were exposed to these agents in vitro, using a modified neutral red release assay. In addition, the morphology of these cells was assessed by light microscopy. Although all the topical glucocorticoids tested proved toxic to both cell types, there were major differences between glucocorticoids in their effect on fibroblasts. Hydrocortisone and the non-halogenated double-ester-type glucocorticoids were less toxic than the conventional medium potency topical glucocorticoids tested (betamethasone valerate and desoximethasone). In particular, hydrocortisone aceponate was less toxic than betamethasone valerate (P < or = 0.05). In general, the effect of topical glucocorticoids on the cells, based on neutral red release, was more marked with keratinocytes than with fibroblasts. Although the ranking order with respect to the toxic potential was similar, a clear-cut difference was not observed between non-halogenated double-ester-type glucocorticoids and betamethasone valerate. Morphological changes due to glucocorticoid exposure followed the same pattern with both keratinocytes and fibroblasts. The neutral red release assay is able to discriminate between the cytotoxic effects of chemically differing topical glucocorticoids on human keratinocytes and fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1995

Interaction of liposomes with human epidermis reconstructed in vitro.

Upon topical application of liposomes of the large unilamellar vesicle type to human epidermis reconstructed in vitro, there is a dose-dependent alteration of the morphology of both the stratum corneum and the living part of the epidermis. In particular, shrunken lipid droplets are found between corneocytes and keratinocytes. Sometimes, corneocytes show inclusions reminiscent of 'cholesterol crystals'. Corneocytes, moreover, show a decreased density. Both corneocytes of the various layers of the stratum corneum and keratinocytes belonging to the uppermost layer of the living epidermis show particularly osmophilic membranes, indicating lipid transfer. Intact liposomes or their remnants can sometimes be seen between corneocytes of the upper strata. The presence of liposomal lipid within the stratum corneum is supported by the presence of gold particles used as a marker. There is, however, no evidence for the uptake of intact liposomes by the living epidermis, or their passage through this compartment of the skin.

Culture Techniques↗
PubMed1995

Allergic airborne contact dermatitis from essential oils used in aromatherapy.

Contact allergy to various essential oils used in aromatherapy was demonstrated on patch testing in a 53-year-old patient suffering from relapsing eczema resistant to therapy on various uncovered parts of the skin, in particular the scalp, neck and hands. Sensitization was due to previous exposure to lavender, jasmine and rosewood. Laurel, eucalyptus and pomerance also produced positive tests, although there was no hint of previous exposure. A diagnosis of allergic airborne contact dermatitis was thus established. On topical and systemic glucocorticoid treatment (peroral methylprednisolone at an initial dose of 60 mg/day) the skin lesions eventually resolved. Due to persistence of the volatile essential oils in the patient's home after a year-long use of aroma lamps, complete renewal of the interior of the patient's flat was considered essential. Due to changing self-medication habits, with increasing orientation to 'natural' modes of treatment, increasing numbers of such sensitizations might be on the horizon.

Air Pollutants↗
PubMed1995

Results of German multicenter study of antimicrobial susceptibilities of Trichophyton rubrum and Trichophyton mentagrophytes strains causing tinea unguium. German Collaborative Dermatophyte Drug Susceptibility Study Group.

Thirty-two strains of Trichophyton rubrum and 16 strains of Trichophyton mentagrophytes isolated from patients with tinea unguium in various parts of Germany were subjected to a microdilution test with six systemic or topical antimycotic agents. Apart from griseofulvin, there were no species-specific differences between the two species. Terbinafine was the most active antimycotic agent, with a MIC not exceeding 0.05 micrograms/ml.

Antifungal Agents↗
PubMed1995

Increased expression of Candida albicans secretory proteinase, a putative virulence factor, in isolates from human immunodeficiency virus-positive patients.

The increased prevalence and the severity of oropharyngeal candidiasis in human immunodeficiency virus (HIV)-positive patients are attributed exclusively to the virus-induced immune deficiency of the host. The present study was aimed at answering the question of whether Candida albicans secretory proteinase, a putative virulence factor of the opportunistic C. albicans yeast, has any potential influence on the clinical manifestation of oropharyngeal candidiasis in HIV-positive patients. We measured the secretory proteinase activities of clinical C. albicans isolates from the oropharynges of either HIV-positive individuals (n = 100) or a control group (n = 122). The mean secretory proteinase activity of C. albicans isolates from the HIV-positive group (4,255 +/- 2,372 U/liter) was significantly higher compared with that of isolates from the control group (2,324 +/- 1,487 U/liter) (P < 0.05). The higher level of secretory proteinase activity in the culture supernatants of individual C. albicans isolates correlated with the increased level of proteinase expression on the cell surface, as revealed by cytofluorometry, and with higher levels of secretion of the immunodetectable protein, as shown by Western blotting (immunoblotting). Proteinase activity within the population of C. albicans isolates from HIV-positive individuals was independent of the patient's clinical disease stage and the CD4+/CD8+ cell numbers. Furthermore, no correlation of the proteinase activities with the C. albicans serotype was found, although C. albicans serotype B was significantly more frequent in the HIV-positive group (40%) compared with that in the control group (12%). However, a positive correlation of proteinase activity to antifungal susceptibility was evident. The C. albicans isolates from the HIV-positive group that were characterized by higher levels of proteinase activity were also less susceptible to the widely used azole antifungal ketoconazole and fluconazole. Collectively, the present data are consistent with a concept of early preferential selection of a subpopulation of C. albicans in HIV-infected patients.

Adult↗
PubMed1995

The concept of the acid mantle of the skin: its relevance for the choice of skin cleansers.

Whereas soap has long been the only cleansing agent, a new generation of cleansers, the so-called synthetic detergents or syndets, has been developed during the last decades. They offer a wide variety of formulations and are therefore becoming more and more important for cleansing of diseased and healthy skin. Among the syndets, especially those with a pH of about 5.5 seem to be relevant. In contrast to alkaline soap, they do not interfere with the cutaneous microflora, whose composition is linked to the skin surface pH. As their irritancy potential might be even lower than that of soap, the benefit-to-risk ratio of syndets appears favorable.

Acids↗
PubMed1995

Tolerance to different toilet paper preparations: toxicological and allergological aspects.

BACKGROUND AND DESIGN: A controlled open trial was performed in 40 individuals suffering from chronic perianal eczema. Various toilet paper preparations representing the conventional type made of pure cellulose, the recycled and the moist type were investigated using the patch test as were allergens possibly related to toilet paper. In addition, a chronic use test and a repeated rubbing test were performed with a conventional and a recycled toilet paper preparation. RESULTS: A total of 20 patients could be evaluated in full. A variety of reactions were seen in the patch test, most of which were of the allergic type. Allergens included many different chemical entities, e.g. preservatives used in moist toilet paper such as Kathon CG and Euxyl K 400. In a volunteer allergic to Euxyl K 400, allergy to the moist toilet paper regularly used by him was established. After discontinuation of its application, perianal dermatitis disappeared. In the repeated rubbing test at the forearm, 10 volunteers showed a reaction with the recycled paper preparation while no such reaction was seen upon the application of the conventional type of toilet paper. The validity of these findings was corroborated by corresponding results in the use test. CONCLUSION: There is clearly a potential for allergic reactions to components of moist toilet paper and reactions to recycled toilet paper presumably irritant by nature. These irritant reactions are probably caused by the rough texture of current paper types and do not reflect the presence of potentially toxic ingredients such as metal salts.

Adult↗