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Biomedical subjects

G Mahrle

Publications and source records attributed to G Mahrle.

At least 19 recordsLinked to original sources
PubMed1996

Human keratinocyte culture from the peritonsillar mucosa.

Tonsillectomy tissue can be used as a routine source for cultures of oropharyngeal keratinocytes. In so doing, a peritonsillar strip of unaltered mucosa was dissected in the upper submucosa. Subsequent trypsinization yielded 7.0 +/- 3.4 x 10(6) keratinocytes per bilateral tonsillectomy. Keratinocyte attachment and growth in primary culture were promoted by sublethally irradiated 3T3 murine fibroblasts. Three subcultures could be performed without a feeder layer and were characterized by a population doubling time of 4.5 days during log growth phase. Electrophoretic and immunoblot analysis of the third subculture revealed a strong expression of keratin pairs 5/14 and 6/16 as well as keratins 7 and 19, whereas keratins 8/18 were expressed less intensely. The lowest intensity, was found for keratin 13, which is known to be indicative of the differentiated mucosa. The culture technique thus provides an easily available in vitro model for morphological and functional studies on the epithelial compartment of human oropharyngeal mucosa.

3T3 Cells↗
PubMed1996

Effect of fumaric acid, its dimethylester, and topical antipsoriatic drugs on epidermal differentiation in the mouse tail model.

Fumaric acid, fumaric acid dimethylester, and the dithranol derivative C4-lactone were studied in the mouse tail test to evaluate their effects on epidermal cell differentiation compared with other topical antipsoriatic drugs, such as betamethasone, calcipotriol, and dithranol. Mouse tails were treated for 2 weeks and longitudinal histological sections prepared of the tail skin. The length of the orthokeratotic regions (stratum granulosum) was measured on 10 sequential scales per tail and expressed as percentage of the full length of the scale. In addition, epidermal thickness was measured and the efficacy of the various compounds evaluated. In comparison to 2% salicylic acid ointment, all tested compounds except fumaric acid significantly (p < or = 0.05) increased the proportion of the orthokeratotic region. C4-lactone and calcipotriol were less effective than dithranol, fumaric acid dimethylester only moderately influenced cell differentiation, and betamethasone showed the least potent effect. Dithranol was the most potent substance inducing orthokeratosis without increasing epidermal thickness.

Administration, Topical↗
PubMed1996

Soluble Pityrosporum-derived chemoattractant for polymorphonuclear leukocytes of psoriatic patients.

The chemoattraction of polymorphonuclear leukocytes (PMNs) from psoriatic patients, atopic patients and healthy control persons by Pityrosporum orbicularelovale was investigated using the Boyden chamber method. The chemotactical attraction of PMNs from psoriatic patients by Pityrosporum (stimulation index SI = 58 +/- 50) was significantly increased (p < 0.05) compared to PMNs from atopic patients (SI = 20 +/- 17) and control persons (SI = 26 +/- 24). This effect seems to be specific for Pityrosporum, since the chemotactical response to Staphylococcus epidermidis was not increased in psoriasis. The chemotactical factor produced by Pityrosporum is hydrophilic and is destroyed by acid hydrolysis, indicating its protein nature. The yeast Pityrosporum may thus play a role in the koebnerization of psoriasis.

Adult↗
PubMed1995

Low-dose short-term cyclosporine versus etretinate in psoriasis: improvement of skin, nail, and joint involvement.

BACKGROUND: High-dose cyclosporine therapy significantly alleviates psoriasis within 2 to 4 weeks but is associated with a high rate of side effects. Reports are conflicting on the frequency and promptness of relapse after discontinuation of cyclosporine therapy. OBJECTIVE: Our purpose was to compare the efficacy and safety of low-dose cyclosporine with that of etretinate and the stability of remission after replacing cyclosporine therapy with topical anthralin during tapering of cyclosporine. METHODS: In a multicenter study 210 patients with moderate to severe chronic plaque-type psoriasis were randomly assigned to treatment with cyclosporine or etretinate. The initial dosages were 2.5 mg/kg/day for cyclosporine and 0.5 mg/kg/day for etretinate, which could be individually adjusted to 5.0 and 0.75 mg/kg/day, respectively. After a treatment phase of 10 weeks (phase 1) patients receiving cyclosporine were again randomly assigned to a group in which cyclosporine was replaced by topical dithranol (anthralin), or to another group in which the drug was tapered during the next 12 weeks (phase 2). All patients treated with etretinate discontinued therapy after 10 weeks and used topical dithranol. RESULTS: Mean Psoriasis Area and Severity Index decreased by 71% in the cyclosporine group and by 47% in the etretinate group during phase 1. After 10 weeks of treatment 47% of the patients treated with cyclosporine and 10% of those treated with etretinate showed a reduction of more than 80% in skin involvement. Sixty-four percent of the cyclosporine group and 48% of the etretinate group did not require an increase in the initial dosage, resulting in a mean daily dose of 3.0 and 0.53 mg/kg, respectively. There was significant alleviation of nail involvement and joint complaints in both groups. In phase 2 the increase in mean Psoriasis Area and Severity Index and the incidence of relapse were significantly higher in patients in whom cyclosporine was discontinued and replaced by dithranol than in patients in whom cyclosporine was tapered or who were pretreated with etretinate. During treatment four patients from the cyclosporine group and three patients of the etretinate group discontinued the study because of side effects. CONCLUSION: Low-dose short-term cyclosporine therapy for psoriasis is, in comparison with etretinate, highly effective and well tolerated. Individually adjusted cyclosporine therapy allows the majority of patients to continue the low dosage of 2.5 mg/kg/day and still achieve a good clinical response. Remission can be better preserved by tapering the drug than by discontinuing treatment abruptly.

Administration, Cutaneous↗
PubMed1995

Intestinal microsporidiosis with Septata intestinalis in a patient with AIDS--response to albendazole.

Microsporidiosis is a common finding in HIV-infected patients who have diarrhoea. The species most commonly causing gastrointestinal disease is Enterocytozoon bieneusi. Recently Septata intestinalis has been described as a cause of diarrhoea and disseminated infection in patients with AIDS. A 44-year-old homosexual man with severe immunodeficiency (CD4 cell count 40/microliters) had a history of watery diarrhoea for 2 weeks. Microsporidian spores measuring 1.2 to 1.5 x 2.5 to 3.0 microns were found in stool samples. Electron microscopy of duodenal biopsies confirmed the diagnosis of intestinal microsporidiosis and showed parasitophorous vacuoles with the typical ultrastructure of S. intestinalis. The patient was treated with albendazole (400 mg twice daily) and became asymptomatic within 4 days. No spores could be detected in stool samples after a treatment period of 14 days. About 25 infections with S. intestinalis have been reported to date, and the case presented here is the first in a German patient.

AIDS-Related Opportunistic Infections↗
PubMed1995

Immunologically confirmed disseminated, asymptomatic Encephalitozoon cuniculi infection of the gastrointestinal tract in a patient with AIDS.

Microsporidia are obligate intracellular protozoan parasites that infect a broad range of vertebrates and invertebrates. They are increasingly recognized as human pathogens, especially in patients infected with human immunodeficiency virus (HIV). Organisms of the genus Encephalitozoon have been implicated as a major cause of disseminated microsporidian infections in persons with AIDS. Until recently, E. hellem was the only Encephalitozoon species confirmed by antigenic or nucleic acid methods to have infected humans. We describe the clinical course and morphological features of a case of disseminated microsporidian infection with Encephalitozoon cuniculi in an HIV-infected patient with chronic sinusitis, rhinitis, and keratoconjunctivitis. Parasites were found in conjunctival swab, nasal discharge, sputum, urine, stool, and duodenal biopsy specimens, but no pulmonary, renal, or gastrointestinal symptoms were documented. The patient was treated with albendazole (400 mg po b.i.d.), resulting in complete remission of his ocular and nasal symptoms, and microsporidian spores disappeared from all sites. To our knowledge, this case is only the second of E. cuniculi infection in humans that has been confirmed by either antibody- or nucleic acid-based methods, and it is the first in which an Encephalitozoon species has been found in the intestinal tract of a human. Microsporidiosis is an important emerging opportunistic infection in HIV-infected patients and, as documented in this report, has an expanding clinicopathologic spectrum.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Up-regulation of keratin 17 expression in human HaCaT keratinocytes by interferon-gamma.

The immortalized human keratinocyte cell line HaCaT was used to assess the effect of interferon-gamma (IFN-gamma) on expression of keratin K17. Both IFN-gamma and K17 have been implicated in the pathophysiology of psoriasis. Western and quantitative enzyme-linked immunosorbent assay analyses demonstrated increasing induction of K17 protein by 48 h exposure to IFN-gamma at concentrations of 10, 50, and 250 U/ml. At 50 U/ml IFN-gamma, immunohistochemical analysis revealed numerous K17-positive foci, whereas in situ hybridization demonstrated K17 message in the majority of cells. In addition, at low (5 U/ml) concentrations of IFN-gamma, cell proliferation and protein synthesis decreased, as determined by 3H-thymidine labeling and 14C-amino acid uptake. These data suggest that aberrant K17 expression observed in psoriatic lesions may be a consequence of IFN-gamma overexpression, and that the HaCaT cell line may be a useful in vitro model system to elucidate the underlying mechanisms.

Antigens, Differentiation↗
PubMed1995

Efficacy and tolerability of multiple-dose SDZ IMM 125 in patients with severe psoriasis.

Although cyclosporin is effective in immunosuppression following organ transplantation and in the treatment of psoriasis, its use is limited by its side-effects, notably impaired renal function and hypertension. As SDZ IMM 125, a new derivative of the cyclosporin family, showed considerable immunosuppressive activity in experimental studies, with less effect on renal function, it was considered a potential successor to cyclosporin for both indications. In this multicentre, double-blind, placebo-controlled study, the efficacy and tolerability of 40, 100, 200 and 400 mg SDZ IMM 125 daily were studied in 59 patients with psoriasis. Patients were followed for a period of 5 weeks (4 weeks treatment, and 1 week post-treatment observation). A dose-dependent effect of SDZ IMM 125 was observed. A significant correlation was found between the dose of SDZ IMM 125 and changes in the sum of severity scores of three indicator plaques. There was a significant decrease in the body surface area affected by psoriasis in the 400-mg group (P < or = 0.01), whereas a decrease of the global psoriasis severity was observed in the 200-mg (P < or = 0.01) and the 400-mg groups (P < or = 0.001). No serious adverse events occurred during the 4 weeks of treatment. Three patients discontinued treatment because of adverse events (one sore throat, two influenza). Clinical adverse events were similar to those reported with cyclosporin, the most frequent being gastrointestinal disturbances. Estimation of renal function indices showed that increases from baseline values were dose-dependent, and appeared to be similar to those seen with cyclosporin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Tissue diagnosis of intestinal microsporidiosis using a fluorescent stain with Uvitex 2B.

AIMS: To detect intestinal microsporidiosis in paraffin wax embedded biopsy specimens using a fluorescence technique incorporating optical brighteners. METHODS: Eight HIV infected patients with confirmed intestinal microsporidiosis (six with Enterocytozoon bieneusi, one with Encephalitozoon intestinalis and one with Encephalitozoon cuniculi infection) and 10 without infection were studied. Tissue sections of paraffin wax embedded duodenal biopsy specimens were stained with 1% Uvitex 2B, coded and analysed independently by two investigators. RESULTS: In all eight cases with confirmed intestinal microsporidian infection, spores could be detected easily in tissue sections using the fluorescence technique. Spores or other elements consistent with microsporidiosis were not found in the 10 patients without infection. CONCLUSION: Staining of tissue sections from paraffin wax embedded intestinal biopsy specimens with stains incorporating Uvitex 2B is a rapid and easy technique for the diagnosis of intestinal microsporidiosis.

AIDS-Related Opportunistic Infections↗
PubMed1994

Antiproliferative and cytotoxic profiles of antipsoriatic fumaric acid derivatives in keratinocyte cultures.

Oral administration with complex mixtures of fumaric acid derivatives is known to have antipsoriatic efficacy. The present studies aimed to clarify the mode of action and toxicity of the individual compounds. Hyperproliferative HaCaT keratinocytes in monolayer cultures were exposed to fumaric acid, dimethylfumarate, zinc monoethylfumarate, calcium monoethylfumarate and magnesium monoethylfumarate at concentrations between 0.4 microM and 960 microM for 48 h. Cell proliferation was studied by [3H]thymidine incorporation. In addition 14C-labelled amino acid uptake and total protein content were measured. Direct cytotoxicity was determined by the release of cytoplasmic lactate dehydrogenase (LDH) into the culture medium. The corresponding 50% inhibition concentrations (IC50) were calculated for DNA/protein synthesis: 2.3/2.5 microM (dimethylfumarate), 133/145 microM (zinc monoethylfumarate), 215/230 microM (calcium monoethylfumarate), 275/270 microM (magnesium monoethylfumarate), > 960/> 960 microM (fumaric acid). The total protein content was less sensitive. Antiproliferative activity was found for dimethylfumarate and to a lesser degree for calcium monoethylfumarate already at the subtoxic concentrations of 1.3 and 4 microM, respectively. In the case of magnesium monoethylfumarate, zinc monoethylfumarate and fumaric acid there was no such dissociation between their cytotoxic and antiproliferative potential. These data indicate that most of the antipsoriatic potential of fumaric therapies is due to the dimethylfumarate compound.

Cell Death↗
PubMed1994

[Peritumoral administered IL-2-induced tumor regression in melanoma. Pilot study].

Since the immune system plays an important role in the rejection of tumours, current tumour therapy includes immunostimulation. This can be done by interleukin 2 (IL-2), which activates T and killer cells and induces lysis of the tumour. Because the intravenous application of IL-2 may have serious side effects, we treated two patients with peritumoral injections in a pilot study. Both patients suffered from multiple cutaneous metastases of melanoma. A total of 31 and 39 x 10(6) IU recombinant IL-2 (Proleukin) respectively was injected in increasing concentrations in one metastasis of each patient. Histologically, almost complete necrosis of the tumour was induced. In comparison with the control specimen, the T-cell-rich infiltrate increased intra- and, in particular, peritumorally. While the ratio of helper to suppressor T cells remained unchanged, the proportions of NK cells, monocytes/macrophages and IL-2-receptor-bearing cells increased. This reaction was restricted to treated metastases. No clinical side effects or laboratory changes were registered apart from local erythema and swelling.

Aged↗
PubMed1994

IL-1 alpha-induced expression of ICAM-1 on cultured hyperproliferative keratinocytes: suppression by antipsoriatic dimethyl-fumarate.

BACKGROUND: In the psoriatic plaque both IL-1 dysregulation and ICAM-1 expression on keratinocytes have been previously described. Furthermore systemic administration of fumarates has been reported to be effective in psoriasis. We, therefore, studied the effect of dimethyl-fumarate ester (DMF) on the putative IL-1-induced ICAM-1 expression. METHODS: Hyperproliferative human keratinocytes (HaCaT cell line) were incubated in 10 to 100 U/mL IL-1 alpha for 24 h with and without preincubation with 0.4-12.0 microM DMF: Expression of ICAM-1 was measured by a special ELISA-APAAP technique. RESULTS: The exposure to IL-1 led to a significant dose-dependent induction of ICAM-1 expression of from 124 +/- 17 to 194 +/- 22% (control 100 +/- 12%), while proliferation remained unaltered. Pretreatment with > or = 4 microM DMF resulted in a distinct suppression of ICAM-1 expression and a slight decrease in proliferation. CONCLUSIONS: The present results show that ICAM-1 expression on hyperproliferative keratinocytes may be triggered by IL-1 alpha and serve as a molecular target for antipsoriatic DMF.

Cell Adhesion Molecules↗
PubMed1994

Anthralin: how does it act and are there more favourable derivatives?

Anthralin is still the most effective and safest therapeutic agent for treatment of psoriasis. Our data may assist toward an understanding of its mode of action and introduce new derivatives, more antiproliferative and less toxic than anthralin in vitro. Anthralin exerts a direct effect on keratinocytes and leukocytes. In time-lapse studies it significantly prolonged the prophase of mitotic keratinocytes in subtoxic doses and suppressed the expression of keratin 6 mRNA in the immediately suprabasal layer of psoriatic epidermis in vivo. Anthralin inhibits the transformation of lymphocytes and the release of reactive oxygen species from activated leukocytes, in vitro. We provide evidence that these effects of anthralin are mediated by protein kinase C. Twelve new hydrophilic derivatives of anthralin, including a 1,8-dimethoxy compound, as well as C-2 and C-10 substituted anthrones were tested on human keratinocytes. The antiproliferative effect of those derivatives bearing lacton rings at a C-10, consisting of 4, 5, or 6 C atoms, exceeded that of anthralin and were equally or less cytotoxic than the parent drug. These compounds had no pro-drug character in vitro, since they did not metabolize via anthralin, as shown by HPLC. These data indicate that there may be anthralin derivatives with more favourable properties for topical therapy than anthralin itself.

Anthralin↗
PubMed1993

Immunohistochemical and immunoelectron microscopic demonstration of chromogranin A in formalin-fixed tissue of Merkel cell carcinoma.

BACKGROUND: Chromogranin A (CGA) is the major protein of neurosecretory granules (NSG) of cells of the diffuse neuroendocrine system, and the amount of CGA corresponds to the number of NSGs. OBJECTIVE: Because formalin fixation may destroy NSGs, a study was performed to examine the presence of CGA in Merkel cell carcinoma (MCC) to determine whether CGA depends on the presence of intact NSGs. METHODS: Formalin-fixed, paraffin-embedded tissue of 15 MCCs was investigated by immunohistochemistry and immunoelectron microscopy for the presence of CGA and NSGs. RESULTS: CGA was demonstrated in 12 of 15 MCCs by immunochemistry and in 6 of 10 MCCs by immunoelectron microscopy although intact NSGs could not be discerned in all cases. CONCLUSION: CGA remains demonstrable even when no morphologically intact NSGs are present, which suggests that CGA is not exclusively responsible for the electron density of NSGs.

Adult↗
PubMed1993

Keratin pattern of acanthosis nigricans in syndromelike association with polythelia, polycystic kidneys, and syndactyly.

BACKGROUND: Acanthosis nigricans (AN) comprises a broad spectrum of etiologic subtypes. The underlying pathomechanisms have not yet been completely clarified. We present a patient affected with a syndromelike AN subtype including disturbed epidermopoiesis as evidenced by immunohistologic findings and in situ hybridization. OBSERVATIONS: A 54-year-old white man contracted AN during childhood. There were connate malformations consisting of webbed toes II/III on the right side and a supernumerary left mammilla. As an adult he developed psoriasis vulgaris, obesity, and latent diabetes mellitus, polycystic kidney and liver disease. With regard to keratin 6 mRNA, and the protein expression of keratin 6/16, KI-67, and proliferating cell nuclear antigen, the AN lesion showed moderate hyperproliferation. A much higher degree of hyperproliferation was evident in psoriatic areas of the patient's skin. In contrast to psoriatic tissue, basal keratinocytes of the AN showed an unusually high expression of keratin 18 and 19 protein. CONCLUSIONS: The observation thus deals with a unique, syndromelike constellation of AN characterized by a particular epidermal pattern of moderate hyperproliferation. A further dysregulation of protein expression in the epidermis is indicated by the demonstration of the rare keratins 18 and 19 in basal keratinocytes of the AN lesion.

Abnormalities, Multiple↗
PubMed1993

[Therapeutic problem. Angiolymphoid hyperplasia with eosinophilia].

A 35-year-old female patient suffered from angiolymphoid hyperplasia with eosinophilia for 9 years, with multiple, exophytic tumours on her left pinna and the surrounding skin. Systemic treatment with gamma interferon and glucocorticoids, intralesional injections of glucocorticoids and argon laser therapy had no effect. After the tumours had been pared away by electrocautery the patient was free of symptoms for 1 year and then developed a small local recurrence. Recurrences are common in angiolymphoid hyperplasia with eosinophilia. Malignant transformation has not been observed. We therefore regard non-radical surgery as the therapy of choice.

Aged↗