Search PubMed⌕ Search

Biomedical subjects

H C Korting

Publications and source records attributed to H C Korting.

At least 127 records · Page 7Linked to original sources
PubMed1992

Atypical presentation of co-existent Haemophilus ducreyi and Treponema pallidum infection in an HIV-positive male.

A 25-year-old homosexual black male presented with asymmetrical perianal ulceration of uncertain clinical origin. Indepth microbiological examination revealed the combined presence of Haemophilus ducreyi and Treponema pallidum. The atypical clinical appearance may have been due to the changed immunological status of the host's being infected with Human Immunodeficiency Virus.

Adult↗
PubMed1992

Influence of the pH-value on the growth of Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes in continuous culture.

A cutaneous isolate of Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes was grown in continuous culture at varying pH-values ranging from 5.0 to 8.5. In terms of the specific growth rate as well as the bacterial density during the plateau phase there were remarkable differences. In particular, Propionibacterium acnes grew much better in the pH 6.0 to 7.0 range than in a more acidic or alkaline milieu. Staphylococcus epidermidis resembled Staphylococcus aureus showing no major difference at pH 5.5 and 7.0. These findings substantiate the hypothesis that minor changes of the pH in the pH 5.5 to pH 6.0 range as to be induced by chemically neutral or alkaline skin cleansers on the human skin surface can increase the number of propionibacteria but not staphylococci remarkably due to the relative alkalinity by itself.

Culture Media↗
PubMed1992

[The effect of cosmetics and dermatologic agents on skin lipids].

The composition of stratum corneum lipids and of sebum lipids is described with respect to their biological function, with special reference to dry skin. In this context, we discuss desiccation and lipid removal by surfactants and the protective and refatting effects of oil bath products and other lipid-containing preparations for topical use.

Cell Membrane Permeability↗
PubMed1992

Is tinea unguium still widely incurable? A review three decades after the introduction of griseofulvin.

BACKGROUND: Tinea unguium, especially of the feet, for ages has been looked on as an incurable disease. Today, therapeutic outcome is still controversial. To evaluate the present state of antifungal therapy of dermatophytoses of the nails, a survey of the pertinent literature has been performed. OBSERVATIONS: The introduction of griseofulvin three decades ago was first considered a major breakthrough. Today, however, conventional griseofulvin treatment regimens must be called disappointing in terms of clinical and microbiological cure to be achieved. Cure rates of 40% to 100% have been reported for fingernail infections, but only 3% to 38% for toenail tinea. Microbiological cure rates look only slightly better. Limited experience suggests that additional measures such as surgical nail avulsion or topical antifungal treatment might improve therapeutic outcome. Toenail avulsion increases cure rates to 47% to 82%. The lack of an adequate follow up, however, makes all statements questionable. CONCLUSIONS: Results are only limited with respect to newly developed oral antifungal agents. Whereas ketoconazole treatment had to be omitted due to its hepatotoxic effect, its congener, intraconazole, is under investigation. High cure rates have been obtained in a preliminary study with oral terbinafine, 0.25 g/d, for 12 months, which have cleared toenail tinea in 15 of 17 patients. The value of topical treatment alone has not yet been definitely established. The application of a topical azole (bifonazole) in combination with chemical nail avulsion, using urea paste under occlusion, has resulted in negative cultures in 62% of the patients 3 months after the end of treatment.

Administration, Oral↗
PubMed1992

Mechanisms of skin adherence, penetration and tissue necrosis production by Haemophilus ducreyi, the causative agent of chancroid.

Haemophilus ducreyi (H. ducreyi) strains, representing both reference strains and low-passage isolates, were investigated in terms of surface structures and enzymatic equipment. The interaction of these factors with host tissue was analysed using new in vitro- and in vivo-models. By electron microscopy studies there was no evidence of an extracellular capsule or surface appendages such as pili or flagella. Interaction of all isolates tested with the lectin Phaseolus vulgaris suggests N-acetyl-D-glucosamine units as common structural features of H. ducreyi cell envelope polysaccharide. In attachment to epithelial cells more than one hemagglutinin might be implicated as different haemagglutination patterns could be observed whereby the activity was not heat-labile, but was abolished by formaldehyde. Hydrophobic interactions might be of importance as well as strains showed a wide range of reactions from hydrophobic to hydrophilic, low hydrophobicity being more marked with the older strains. No elaboration of degradative enzymes based on the measurement of enzymatic activity using insoluble dye-protein complexes could be detected in case of H. ducreyi, using Azocoll and Remazol Brilliantblue hide powder for detection of proteolytic activity and elastinorcein for detection of elastase activity. In vitro studies using human keratinocytes and Vero cells did not show any morphological changes when incubated with H. ducreyi culture filtrates. In vivo studies with a new mouse model for H. ducreyi infection could confirm the results of the in vitro studies. Mere contact to undamaged skin both of whole cell organisms, live or heat-killed, and of culture filtrates did not lead to any reaction or even damage of mouse skin. However, when the outer epidermal layer was overcome by intradermal injection of shaved mice ulcers developed. Tissue necrosis production was not bound to live organisms as dead ones showed the same effect. There is great evidence that this tissue necrosis is associated with H. ducreyi lipopolysaccharide (LPS) because intradermal injection of purified H. ducreyi LPS lead to the same reaction pattern. For the first time a cell mediated immune response could be demonstrated in case of H. ducreyi infection as different antigen preparations of H. ducreyi isolates induced proliferation of lymphocytes isolated from healthy unexposed individuals and from a chancroid-sensitized male. In the latter case measured cell responses were much stronger. The dose-dependent phenomenon was associated with interleukin-2 production. In summary, H. ducreyi isolates do not exhibit cytotoxic effects on the epithelial cells of the skin.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Topical liposome drugs to come: what the patent literature tells us. A review.

Drug-containing liposomes for topical use in dermatology have been devised during the last 10 years. Most recently the clinical superiority to a conventional gel of a topical glucocorticosteroid liposome preparation for eczema has been demonstrated. To get more insight from what may be expected from future liposome preparations for topical treatment, the pertinent patent literature has been reviewed.

Administration, Cutaneous↗
PubMed1991

Absence of extracellular enzyme activity and cytotoxicity in cell-free culture filtrates of Haemophilus ducreyi.

Ten isolates of Haemophilus ducreyi, including seven clinical isolates and three laboratory reference strains, were assessed for their ability to produce extracellular enzymes which might contribute to their pathogenicity. Protease, elastase, lecithinase, lipase or collagenase enzyme activity were not detected in culture filtrates from any of the isolates tested using either plate or spectrophotometrical assays. Furthermore, cell-free culture filtrates did not exhibit cytotoxic activity in vitro when tested using either an established tissue culture cell line (Vero) or a primary cell culture of human keratinocytes. These results suggest that extracellular products do not play a role in host invasion or production of tissue damage by H. ducreyi.

Cell-Free System↗
PubMed1991

Chlamydia trachomatis induces an inflammatory response in the male genital tract and is associated with altered semen quality.

U. urealyticum with 15.8% and C. trachomatis antibodies with 15.4% were the most prevalent microbiological findings in 209 male infertility patients. The inflammatory marker granulocyte-elastase was significantly increased in men with C. trachomatis; these men also showed significantly decreased citric acid levels indicating inflammatory damage of the prostate induced by C. trachomatis.

Antibodies, Bacterial↗
PubMed1991

Dermatophytosis in children and adolescents: epidemiological, clinical, and microbiological aspects changing with age.

During a four year period, a total of 84 cases of dermatophytosis were seen in patients from 0 to 17 years of age attending our out-patient department. The sex distribution was about equal in preadolescents. Males predominated among adolescents. A peak incidence at early school age was due to cases of tinea capitis, mainly caused by Microsporum canis. A peak among adolescents was due to cases of tinea pedis, mainly caused by Trichophyton rubrum. In general, patients with Trichophyton rubrum infections were older than those with other types of dermatophytosis (p less than 0.05). Dermatophytosis due to Microsporum canis was most frequently seen in January and in September (p less than 0.01). Although onychomycosis due to dermatophytes was a comparatively rare disease, it did occur within all age subgroups. Entities which were very frequent in former times and which have become rare during the last decades, such as tinea capitis due to Trichophyton schönleinii, still contribute to the spectrum of dermatophytosis in childhood.

Adolescent↗
PubMed1991

Influence of albumin on itraconazole and ketoconazole antifungal activity: results of a dynamic in vitro study.

The relevance of intense protein binding to the antifungal activity of azole compounds is still a matter of debate. The influence of albumin on the antimicrobial activity of ketoconazole and itraconazole, which exhibit very strong plasma protein binding (99 and 99.8%), was evaluated in vitro. Candida albicans was exposed to continuously changing azole concentrations corresponding to drug levels in serum following an oral dose of 200 mg. Total as well as free drug levels in serum were simulated. The incubation medium was free of proteins or contained 4% human serum albumin. Itraconazole levels reflecting free drug concentrations in humans did not reduce the growth rate of C. albicans, as compared with controls (difference in the log CFU per milliliter at 12 h, 0.03 +/- 0.09), whereas total drug levels were as active in the presence of 4% albumin (mean difference, -0.61) as in its absence (-0.75). The same was true for ketoconazole, except that free drug levels were also active (-1.21 versus -1.39 for total drug levels). This result was due to the higher ketoconazole levels in humans. Thus, in terms of routine susceptibility testing, in vitro total drug levels can be considered relevant.

Antifungal Agents↗
PubMed1991

Do cutaneous coryneform bacteria produce short-chain fatty acids in vitro?

According to an opinion shared by many, human axillary and inguinal odour is related to short-chain fatty acids produced by gram-positive bacteria. Especially coryneform bacteria are said to produce these odiferous substances. After sampling 22 different strains of coryneform bacteria we cultured them for 48 h in a rich medium. Short-chain fatty acids were extracted afterwards by shaking the liquid medium with ether. Gas chromatography was used for detection. Only one of the tested bacteria produced propionic acid. Acetic acid, (iso)butyric acid or (iso)valeric acid could never be detected. The production of substances of the short-chain fatty acid type might, however, be a consequence of the particular substrate found under physiologic conditions by these organisms in human apocrine sweat. The theory that the metabolism of these skin bacteria necessarily produces short-chain fatty acids could not be supported. Another explanation might be that unspecific secreted enzymes of the bacteria are responsible for the production of short-chain fatty acids by a cleavage of skin surface lipids.

Actinomycetales↗
PubMed1991

Commercial glucocorticoid formulations and skin dryness. Could it be caused by the vehicle?

Eczema craquelé can be induced by repeated open application of a topical glucocorticoid, viz. 0.05% clobetasole 17-propionate cream. This might not be invariably due to the active component. Comparison of the skin surface roughness as assessed by profilometry and as expressed by RZDIN showed a decrease after repeated open application of 0.1% betamethasone 17-valerate cream and 0.25% prednicarbate cream, but an increase following the vehicle of the latter preparation. Thus commercial oil-in-water emulsion preparations seem to be potentially injurious to human skin, though this may be masked when a glucocorticoid is added.

Administration, Cutaneous↗
PubMed1991

[Cultural protection of a bullous form of Tinea pedis].

While maceration, hyperkeratosis and vesicles are well known as typical clinical correlates of dermatophyte infection of the feet it seems to be still controversial if bullae also belong to the clinical spectre. In a 48-year-old female Trichophyton rubrum could be cultured from the fluid obtained by aspiration of an interdigital bulla. In another case Trichophyton mentagrophytes could be isolated from the interdigital space but not from a bulla found on the sole microscopic investigation, however, being positive. This backs the hypothesis that blisters found on the foot can be due to the local presence of dermatophytes.

Adolescent↗
PubMed1991

[Treatment of seborrhoeic eczema with ketoconazole in comparison with an active agent-free cream].

Both systemic and topical application of ketoconazole (CAS 65277-42-1) have been found effective in seborrhoeic dermatitis. The topical application of 2% ketoconazole in a cream base in particular has so far only once been compared to the application of the vehicle. Statistical analysis, however, has only been descriptive. In the present trial including 60 patients 2% ketoconazole cream (Nizoral) and a bland cream have been compared in a randomised, controlled fashion. Both erythema and scaling were found markedly more reduced in the verum group (p = 0.003 and p = 0.006, resp.). Hence the topical application of 2% ketoconazole cream can be considered as rational treatment of seborrhoeic dermatitis the more so as the application of the drug was well tolerated.

Administration, Topical↗
PubMed1990

Effect of iron limitation on protein composition and ultrastructure of Haemophilus ducreyi.

Protein profiles of whole cells of Haemophilus ducreyi grown in the presence or absence of the iron chelator desferal, were compared by polyacrylamide gel electrophoresis. Each of four strains produced novel proteins in the range 43-160 kDa when cultured under conditions of reduced iron availability. At some sub-inhibitory concentrations, desferal produced enhanced growth, possibly due to it functioning as an exogenous siderophore. Organisms grown under conditions of reduced iron availability ultrastructurally showed also large periplasmic spaces between cytoplasm and outer membrane.

Bacterial Proteins↗
PubMed1990

Liposome encapsulation improves efficacy of betamethasone dipropionate in atopic eczema but not in psoriasis vulgaris.

The effect of a liposomal preparation of beta-methasone dipropionate (0.039%, BDP) has been compared to that of a commercial propylene glycol-gel containing 0.064% BDP in a double-blind, randomized, paired trial lasting 14 d in 10 patients with atopic eczema and 10 patients with psoriasis vulgaris. In eczema, the liposome preparation tended to reduce erythema and scaling more than the conventional gel, the difference in the latter parameter being significant on Day 7. There was greater improvement of psoriasis on the side treated with the reference gel. Hence, liposome encapsulation of BDP may increase the antiinflammatory action but not the antiproliferative effect. Since inhibition of mitotic activity is linked to the atrophogenicity of topical corticosteroids, the results suggest that liposome encapsulation may improve the benefit-risk ratio in eczema.

Adult↗
PubMed1990

Skin tissue fluid levels of cefotiam in healthy man following oral cefotiam hexetil.

Cefotiam hexetil is a pro-drug of cefotiam available for oral administration. To evaluate cefotiam concentrations at the active site in skin and soft-tissue infections, drug levels in skin suction blister fluid (SBF), cantharides blister fluid (CBF) and serum were determined. Six healthy subjects received oral cefotiam 400 mg as cefotiam hexetil. On an other day 200 mg was injected intravenously. Following the oral dose, the bioavailability of cefotiam was 45.5%, and the maximum concentration in serum of 2.6 mg.l-1 was obtained at 2.1 h. Peak concentrations in both types of blister fluid (0.9 mg.l-1) were significantly lower than after the iv dose (SBF 1.4 mg.l-1, CBF 1.5 mg.l-1), and the peak levels occurred later (3.3 versus 1.5 h in CBF). Despite the delay, the extent of penetration was about 100% following either mode of administration (SBF, iv dose 112%, oral dose 117%). The cefotiam level in skin blister fluids declined significantly more slowly than the serum level. Following the oral dose, the mean terminal half life was serum 0.8 h, SBF 2.6 h and CBF 4.6 h. Cefotiam concentrations in the blister fluids were close to the MIC90 of Staphylococcus aureus, S. epidermis and H. influenzae and exceeded the MIC90 of Streptococci, E. coli and Proteus mirabilis. Thus, the oral administration of cefotiam 400 mg t.i.d. should be curative in the majority of bacterial infections of the skin and soft-tissues.

Administration, Oral↗