[Interferon-alpha-induced psoriasis vulgaris]

In recent years, interferon-alpha has become widely used for systemic therapy of tumours and infectious diseases. Well-known cutaneous side effects include dry skin, pruritus and hair loss. Since 1986, 17 patients with renal cell carcinoma, malignant melanoma, hepatitis B and C, carcinoid syndrome and hairy cell leukemia have been reported in whom psoriasis with or without psoratic B joint involvement was induced or exacerbated by systemic interferon-alpha therapy. In these patients, the drug was discontinued because of the severity of the psoriatic symptoms induced. The psoriatic lesions then resolved in nearly all patients within 2 weeks to 6 months, but in 10 of 22 patients treated with interferon-alpha specifically for psoriasis exacerbation was reported. We report three new cases of interferon-alpha-induced psoriasis. The patients were treated with the drug for HIV-associated Kaposi's sarcoma, renal cell carcinoma, and hepatitis C. We conclude that interferon-alpha can provoke psoriatic skin and joint symptoms, especially when additional precipitating factors are involved. In patients in whom such risks are present careful consideration of the benefit/risk ratio and concomitant antipsoriatic treatment are essential if interferon-alpha therapy is to be continued.

[Therapeutic experiences with extracorporeal photopheresis. Technical procedure, follow-up and clinical outcome in 31 skin diseases]

Extracorporeal photophoresis (ECP), a therapeutic modality that has been under investigation for some years, is based on separation of a leucocyte/lymphocyte-enriched cell fraction from the peripheral blood, extracorporeal treatment of the cells with 8-MOP/UVA and subsequent reinfusion of the cells in the patient. Its main effects seem to consist in changes to the immunologic behaviour of the photoinactivated/modulated cells. The immune response of the host is obviously stimulated by this treatment. ECP is normally performed for 4 h per day on 2 consecutive days every 4 weeks. The treatment is well tolerated and causes few side effects. In our department, 1210 ECP treatments were administered to 41 patients between 1990 and 1994 and a preliminary evaluation was performed. These patients included 21 with cutaneous T-cell lymphoma (CTCL), 10 with progressive systemic scleroderma, 4 with chronic graft-versus-host disease and 1 each with pemphigus vulgaris, epidermolysis bullosa acquisita, lupus erythematosus and cutaneous mucinosis. Patients with erythroderma and preserved immunocompetence achieved the best responses of all patients with CTCL. A treatment combining ECP with rIFN-alpha, PUVA and/or radiation was also successful in patients with tumour-stage CTCL and lymph node involvement. Progressive systemic scleroderma responded in more than 50% of our cases. Treatment results were impressive in 4 patients with chronic graft-versus-host disease presenting with sclerodermatous and lichenoid changes of the skin and mucous membranes. A clear improvement was also observed in the patient with pemphigus vulgaris refractory to standard therapies and in another patient with scleromyxoedema (Arndt-Gottron syndrome). The effectiveness of ECP seems to be quite well established in CTCL, but remains to be examined in autoimmune dermatoses. ECP is an attractive addition to the dermatological therapies available but our experience is still preliminary.

[Rare variants of cutaneous T-cell lymphomas]

Besides the classical forms of cutaneous T-cell lymphoma (C-CTCL), such as mycosis fungoides and Sézary's syndrome, unique variants may be encountered. The classification of these rare cutaneous T cell lymphomas is problematic and controversial. Newer classifications of lymphoma in general, such as the Revised European-American Lymphoma (REAL) Classification, emphasize well-established clinico-pathological entities. It seems appropriate to attempt to bring greater clarity to the classification of cutaneous T-cell lymphomas using the same principles. In this review, we list and characterize the rare variants of cutaneous T-cell lymphoma, such as (1) clinical, histological and immunological variants of mycosis fungoides; (2) progressive cutaneous T-cell lymphoma (P-CTCL) including transformed classical cutaneous T-cell lymphoma (TC-CTCL) and primary progressive cutaneous T-cell lymphoma (PP-CTCL); (3) angiocentric and angioimmunoblastic cutaneous T-cell lymphomas; (4) large cell anaplastic, CD30+ cutaneous T-cell lymphoma; (5) HTLV-I-associated adult T-cell leukemia/lymphoma (ATLL); (6) cutaneous manifestations of primary extracutaneous T-cell neoplasias; (7) unclassifiable cutaneous T-cell lymphoma.

[Clinical fluconazole and itraconazole resistance of oro-gastrointestinal candidiasis in a patient with AIDS]

We report on a 32-year-old male patient with advanced acquired immunodeficiency syndrome (AIDS), who had severe candidiasis of the gastrointestinal tract. Treatment with fluconazole, 200 mg/day, was introduced. After oral intake of fluconazole over 5 months itraconazole 200 mg/day was given for 1 month. However, fungal infection still persisted. The antifungal activity of fluconazole, itraconazole and ketoconazole against Candida albicans was evaluated by means of the microdilution test by determining the 90% inhibitory concentration of each drugs. A high minimal inhibitory concentration (MIC) was detected for fluconazole (50 micrograms/ml) revealing fluconazole resistance. The susceptibility to itraconazole was borderline (MIC 0.125 micrograms/ml) and that to ketoconazole was markedly lowered (MIC 0.25 micrograms/ml). Plasma levels of itraconazole were also found to be lowered. In HIV patients the gastrointestinal absorption of azole derivatives is often reduced. Therefore, the clinical resistance of Candida albicans to itraconazole can be explained by reduced susceptibility after azole therapy and also by the decreased absorption of the drug in HIV patients.

The vitamin D3 analogue, calcipotriol, induces sphingomyelin hydrolysis in human keratinocytes

The possible role of sphingomyelin cycle for the regulation of cell proliferation was investigated in human keratinocytes. The time-dependent breakdown of sphingomyelin was observed in the immortalized human keratinocyte cell line HaCaT as well as in primary human keratinocytes thereby providing evidence that the sphingomyelin cycle might be of importance in the epidermis. Peak levels of 20-30% sphingomyelin hydrolysis were measured 3 h after treatment of the cells with 1 alpha,25-dihydroxyvitamin D3 or with the vitamin D3 analogue, calcipotriol. The decrease of sphingomyelin upon addition of vitamin D3 or calcipotriol was accompanied by an approximately 70% increase of ceramide in the cells. The effects of vitamin D3 and calcipotriol on sphingomyelin breakdown were paralleled by their antiproliferative potency. Furthermore, the cell-permeable ceramide, N-acetylsphingosine, and natural ceramide inhibited cell proliferation of human keratinocytes. The results presented suggest that induction of the sphingomyelin cycle represents one mechanism mediating the therapeutic effect of calcipotriol in treatment of psoriasis.

The 5 alpha-reductase system and its inhibitors. Recent development and its perspective in treating androgen-dependent skin disorders

5 alpha-Reductase, the enzyme system that metabolizes testosterone into dihydrotestosterone, occurs in two isoforms. The type 1 isozyme is composed of 259 amino acids, has an optimal pH of 6-9 and represents the 'cutaneous type'; it is located mainly in sebocytes but also in epidermal and follicular keratinocytes, dermal papilla cells and sweat glands as well as in fibroblasts from genital and non-genital skin. The type 2 isozyme is composed of 254 amino acids, has an optimal pH of about 5.5 and is located mainly in the epididymis, seminal vesicles, prostate and fetal genital skin as well as in the inner root sheath of the hair follicle and in fibroblasts from normal adult genital skin. The genes encoding type 1 and type 2 isozymes are found in chromosomes 5p and 2p, respectively, and each consists of 5 exons and 4 introns. During the last decade, several steroid analogues and non-steroid agents have been developed to interfere with 5 alpha-reductase activity. Finasteride, which has a higher affinity for the type 2 isozyme, is the first 5 alpha-reductase antagonist clinically introduced for treatment of benign prostate hyperplasia. The clinical evaluation of finasteride or other 5 alpha-reductase inhibitors in the field of dermatology has been very limited; in particular, those that selectively bind to type 1 isozyme (e.g. MK-386, LY191704) may be regarded as candidates for treatment of androgen-dependent skin disorders such as seborrhoea, acne, hirsutism and/or androgenetic alopecia.

Incomplete expression of the tyrosinase gene family (tyrosinase, TRP-1, and TRP-2) in human malignant melanoma cells in vitro

Sequence analysis of two clones found repressed in melanoma cell lines in earlier studies showed 9F2 to be identical with the TRP-1 gene and 6F5 with TRP-2 containing a long untranslated 3' end. For further investigation of the expression of the tyrosinase gene family in normal and malignant melanocytic cells, a series of melanoma cell lines and of cultured melanocytes were analyzed by Northern blotting and by reverse transcriptase-polymerase chain reaction (RT-PCR). The Northern blots were probed with cDNA fragments specific for TRP-1, TRP-2, and tyrosinase, for nested tyrosinase-PCR the outer primers specified a 284 bp and the nested primers a 207 bp fragment. Investigations on 14 established melanoma cell lines grown in different media compared with seven normal human melanocyte (NHM) cultures revealed that all three pigment genes were expressed in NHM, whereas pigment gene expression was found repressed in nearly all melanoma cell lines and was completely absent in 4 of 14 specimen. In particular, tyrosinase and TRP-2 genes were found always to be expressed together, and TRP-1 mRNA alone was absent in four melanoma cell lines. Negativity of cultured melanoma cells for tyrosinase mRNA was confirmed by nested RT-PCR, and gene deletion was ruled out by genomic Southern blots. The gene expression seemed independent from the type of medium used for cultivation. These findings indicate repressed or lacking expression of pigment genes in melanoma cell lines, most likely due to regulatory mechanisms, and that differences may exist between tyrosinase and TRP-2 on one hand and TRP-1 on the other. Overall, it seemed that RT-PCR for tyrosinase has limited value for identifying melanoma cells in the peripheral blood of melanoma patients; TRP-1, TRP-2, and other, additional markers may be required.

Two new sphingomyelin analogues inhibit phosphatidylcholine biosynthesis by decreasing membrane-bound CTP: phosphocholine cytidylyltransferase levels in HaCaT cells

The effects of two newly synthesized sphingomyelin analogues on phosphatidylcholine biosynthesis were investigated in the immortalized human keratinocyte cell line HaCaT. N-Acetyl-erythro-sphingosine-1-phosphocholine (AcSM) and N-octanoyl-erythro-sphingosine-1-phosphocholine (OcSM) inhibited the incorporation of choline into phosphatidylcholine with half-inhibitory concentrations (IC50) of 6 micrograms/ml and 10 micrograms/ml respectively. Further experiments revealed that AcSM and OcSM interfered with the translocation of the rate-limiting enzyme of phosphatidylcholine biosynthesis, CTP:phosphocholine cytidylyltransferase (EC 2.7.7.15), in HaCaT cells and inhibited cytidylyltransferase activity in vitro. Despite the fact that OcSM was a potent inhibitor of cytidylyltransferase in vitro, its effects on phosphatidylcholine biosynthesis and translocation of cytidylyltransferase in HaCaT cells were less pronounced as compared with AcSM. Finally, we showed that the comparatively strong effects of AcSM in cell culture experiments were due to the uptake of large amounts of this sphingomyelin analogue into the cells. The results presented demonstrate that the activity of cytidylyltransferase may be negatively regulated by a high ratio of choline head group-containing sphingolipids.

[Management of primary malignant melanoma of the skin in German-speaking countries 1983-1993. A study of the Malignant Melanoma Central Register of the German Society of Dermatology]

During the past decade more than 90% of all melanoma patients in the German-speaking countries have been diagnosed with a primary tumour alone. Therefore, surgical intervention has been the most important element in the management of these patients. The present investigation was performed to analyse the different surgical procedures used in the treatment of primary melanoma during the years 1983-1993. The primary treatment of 15,054 patients with malignant melanoma and without recognizable metastasis has been examined. During the time period under investigation the percentage of cases treated with two-step surgical management increased from 30% to 60%. Primary excision was performed in local anaesthesia in 40% of all patients in 1983, whereas in 1993 surgical intervention under local anaesthesia had increased up to 80%. Over the same time, the average safety margin decreased from 33 mm to 21 mm for the final excision of primary melanomas, and this decrease was paralleled by marked decrease in the average thickness of the tumours excised from 2.1 to 1.5 mm. Elective node dissection was performed in 5% of all patients in 1983, whereas 9% of patients underwent elective node dissection in 1993. The different centres participating were found to differ noticeably in the therapeutic procedures applied for similar indications. In conclusion, the management of primary malignant melanoma has changed considerably during the years 1983-1993 in the German speaking area in favour of a two-step surgical procedure, local anaesthesia for the excision of the primary tumour and smaller safety margins. It seems that earlier diagnosis of the tumour and also ideas about treatment design may be responsible for these changes.

[Generalized molluscum contagiosum in an African child with AIDS]

A 12-year-old girl from Zaire with AIDS (CDC: P2 D1) presented with a generalized molluscum contagiosum infection. She had suffered from systemic cryptococcosis and from cryptosporidiosis several months before admission. While molluscum contagiousum infection is usually a self-limiting disease in immunocompetent persons, a fulminant appearance and persistence of giant mollusca occurs with advanced immunodeficiency. Histological and immunohistological examinations showed a severe diminution of Langerhans and T cell populations that might enhance the dissemination of the infection. Molluscum-like lesions of cryptococci have been described, and cutaneous cryptococcosis is the main condition to be considered in the differential diagnosis. Further differential diagnoses should include American and African histoplasmosis, and the cutaneous manifestations of mycobacterial infections, of toxoplasmosis and of Pneumocystis carinii infection.

[The Malignant Melanoma Central Register of the German Society of Dermatology 1983-1993. Epidemiologic developments and current therapeutic management of malignant melanoma of the skin]

The Central Malignant Melanoma Registry of the German Dermatological Society was founded in 1983 and has meanwhile developed into a major continuously updated multicentre project. Up to June 1994, 19,250 reports of cutaneous melanoma had been received, from 41 departments of dermatology in the former Federal Republic of Germany, from 14 departments in the former German Democratic Republic, from 2 departments in Austria, and from 1 department in Switzerland. Analysis of the data revealed some epidemiological trends over time during the years 1983 to 1993. (1) During the last 10 years the percentage of male patients has steadily increased, from an average of 38% in the year 1983 to 46% in 1993. (2) Early diagnosis of malignant melanoma improved during the period of time investigated. The percentage of diagnoses of primary tumour alone increased between 1983 and 1993. The mean tumour thickness (Breslow) decreased in the West Germany from 1.8 mm to 1.3 mm and in East Germany from 2.5 mm to 1.7 mm. The proportion of nodular melanoma decreased correspondingly from 29% to 14% in the former Federal Republic of Germany and from 40.6% to 22.6% in the former Germany Democratic Republic. During the years 1990 and 1993, 64% of melanoma patients with the primary tumour alone were operated on in two consecutive sessions in the former Federal Republic of Germany and 34.2% of those in the former Germany Democratic Republic. During this period 73.7% of all melanoma patients were operated on under local anaesthesia. In recent years surgical operations were more often performed in two consecutive sessions, mostly under local anaesthesia and with decreasing safety margins, in keeping with the decrease in tumour thickness. The present analysis shows that the Central Malignant Melanoma Registry is an important instrument for investigating trends in clinical epidemiology and treatment of malignant melanoma in the German-speaking countries.

The human hair follicle: glycoprotein-related antigenic profile of distinct keratinocyte populations in vivo and their alterations in vitro

The cell surface expression of three glycoprotein antigens, as defined by the monoclonal antibodies BT 15, T 43, and MH 99, was investigated in follicular keratinocyte populations in vivo. In addition, the regulation of glycoprotein synthesis was studied in follicular and interfollicular keratinocytes cultured in vitro. The BT 15 antigen was strongly expressed in the inner root sheath and the area above Auber's line of the hair bulb, whereas the T43 antigen was mainly seen in the outer root sheath. Selectively high expression of the MH 99 antigen was found only in outgrowing germ buds of early anagen follicles. Radioimmunoprecipitation revealed strong signals with BT 15 in freshly prepared follicular keratinocytes, two to three times stronger than those in interfollicular keratinocytes, but the signals clearly decreased by 80% under continuing culture conditions. The T 43 antigen was found by FACS analysis and radioimmunoprecipitation in initially low amounts in both populations, but the signals increased dramatically (up to 50 times) in long-term cultures and in subcultures. The MH 99 antigen was also initially present only in low amounts, in interfollicular rather than in follicular keratinocytes, but its expression increased up to 15-fold with continuing culture and any differences between the two populations disappeared. Our investigation revealed that at least three populations of hair follicle keratinocytes are characterized by different surface glycoprotein antigens, clearly related to their state of differentiation and proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Properties of the carcinoma-associated antigen MH 99/KS 1/4 in normal and transformed human keratinocytes: regulation of synthesis, molecular cross-linking and ultrastructural localization

A 38-kDa cell-surface glycoprotein defined by monoclonal antibody MH 99 is markedly increased in many epithelial tumours. In normal human skin, it is a characteristic marker for germ-cell phenotypic tissues. Although the gene encoding the MH 99 antigen has recently been cloned, and several histological and biochemical studies have been performed, the biological function of this interesting antigen still remains unknown. In the present study, we examined the synthesis of MH 99 in keratinocyte populations showing different in vitro differentiation capacity. Normal keratinocytes, spontaneously immortalized keratinocytes (cell line HaCaT), three SV-40-transformed keratinocyte lines (130, 425, and HaSV), and two squamous cell carcinoma lines (SCL-1 and SCL-2), were compared. Radioimmunoprecipitation revealed the highest levels of synthesis in cell populations with the least differentiation. This was paralleled by an increase of MH 99 synthesis in normal keratinocytes cultured in low concentrations of Ca2+ and by an increase of MH 99 synthesis during subculture of normal keratinocytes. Both phenomena were paralleled by an opposite behaviour of a differentiation marker. Molecular cross-linking and subsequent immunoprecipitation led to a decrease of the MH 99 signal, but an increase of a high molecular weight protein signal was seen. After cleavage of the crosslinker, the MH 99 signal reappeared, whereas the signal of the large protein remained unchanged. Thus, the MH 99 antigen may be associated with a high molecular weight protein on the cell surface, supporting the suggestion of a receptor-like function. Phosphorylation of the molecule could not be detected. Immunoelectron microscopy revealed homogeneous distribution on the cell surface, but cells of the same culture exhibited clear differences in their MH 99 expression. A concept for MH 99 regulation in normal and transformed human keratinocyte populations in vitro is proposed, showing that the synthesis of MH 99 is inversely correlated with cell differentiation. The association with a high molecular weight protein supports the suggestion that the MH 99 antigen interacts with other molecules.

Primary cutaneous melanoma. Optimized cutoff points of tumor thickness and importance of Clark's level for prognostic classification

BACKGROUND

Maximum tumor thickness and level of invasion are known to be the most important prognostic factors for patients with primary cutaneous melanoma. However, the classification of tumor thickness and the question of whether the combination of tumor thickness and level of invasion provides a better prognostic classification than tumor thickness alone are still matters of debate. The present study examined the relationship between tumor thickness and survival probability to define cutoff points of tumor thickness. Secondly, it investigated the prognostic value of the combination of tumor thickness and level of invasion as proposed in the current TNM classification system.

METHODS

A series of 5093 patients with invasive primary cutaneous melanoma followed from 1970 to 1988 at four University centers in Germany (Departments of Dermatology in Tübingen, Würzburg, Berlin-Steglitz, and at the Fachklinik) were analyzed by multivariate Cox models.

RESULTS

The relationship between tumor thickness and relative risk of death caused by melanoma was found to be almost linear to a tumor thickness of 6 mm. For tumors greater than 6 mm, no further marked increase in relative risk was observed. The stratification of tumor thickness with endpoints at 1, 2, and 4 mm resulted in the best fit to the authors' data among all classifications with three endpoints, but differences were only slight. By multivariate analysis, the combination of tumor thickness and level of invasion as proposed by the current TNM classification were found to be prognostically less significant than tumor thickness alone. The prognostic influence of level of invasion was proved statistically only for tumor thickness less than or equal to 1 mm.

CONCLUSIONS

The proposed stratification of tumor thickness with cutoff points at 1, 2, and 4 mm was supported by multivariate statistical analysis. The analysis of the current TNM staging system indicates the precedence of tumor thickness for the staging of patients with primary cutaneous melanoma in the case of discordance between tumor thickness and level of invasion.

Primary cutaneous melanoma. Identification of prognostic groups and estimation of individual prognosis for 5093 patients

BACKGROUND

Numerous investigations have examined prognostic factors for patients with primary cutaneous melanoma. However, only a few studies have been published on the definition of prognostic groups. The first aim of the present study was to determine the relative importance of different prognostic factors in a large collective study. The second aim was to define prognostic groups of patients based on combinations of prognostic factors and to define a model that allows the estimation of individual survival probability.

METHODS

Long term follow-up of 5264 patients with invasive primary cutaneous melanoma was performed from 1970 to 1988 at four German University Departments of Dermatology (Berlin-Steglitz, Münster-Hornheide, Tübingen, and Würzburg). The multivariate Cox model was used to analyze 5093 patients, and 4371 patients with complete information were included in a classification and regression tree analysis (CART).

RESULTS

Tumor thickness, sex, anatomic location, and level of invasion were highly significant prognostic factors according to the multivariate analysis (P < 0.0001). However, histologic subtype and age influenced prognosis less significantly (P < 0.05). The CART analysis resulted in 12 groups defined mainly by tumor thickness, sex, and anatomic location, which were combined into five prognostic groups. The prognostic stratification defined by the five groups was superior compared with the standard TNM model. Ten-year survival rates of the five groups ranged from 97% to 14% (P < 0.0001), and an equation was used to calculate individual survival probabilities based on the significant factors of the Cox model.

CONCLUSIONS

Consideration of all significant prognostic factors of patients with primary cutaneous melanoma investigated in the present study allows for the definition of prognostic groups with a more reliable estimation of prognosis than by previous staging systems and also enables calculation of individual survival probabilities.

Primary cutaneous melanoma. Prognostic classification of anatomic location

BACKGROUND

Anatomic location has been identified by several investigators as a significant prognostic factor for patients with primary cutaneous melanoma (CM). However, the best determination of higher and lower risk sites is still controversial, and the biologic significance of tumor site in the course of primary CM is unknown. The aim of the present study was to identify higher and lower risk sites based on multivariate analysis.

METHODS

A series of 5093 patients with invasive primary cutaneous melanoma followed from 1970 to 1988 at four university centers in Germany was investigated using the multivariate Cox proportional hazard model to analyze the importance of anatomic location for survival probability.

RESULTS

The anatomic location was found to be a highly significant prognostic factor for patients with primary melanoma by multivariate analysis (P < 0.0001). An optimized classification into sites of higher and lower risk with respect to survival was evaluated by multivariate analysis controlling for the possible confounding effects of the other significant prognostic factors. Relative to the lower leg as the prognostically favorable baseline, the following locations were associated with a significantly higher risk of death caused by primary cutaneous melanoma: back and breast (thorax), upper arm, neck, and scalp (TANS regions). The lower trunk, thigh, lower leg, foot, lower arms, hands, and face were identified as lower risk sites.

CONCLUSIONS

Anatomic location was confirmed as an independent prognostic factor for patients with primary cutaneous melanoma. The TANS regions were identified as high risk sites, and the lower trunk, thigh, lower leg, foot, lower arms, hands, and face were identified as intermediate sites.

Identification of genes specifically regulated in human melanoma cells

In order to improve the characterization of human malignant melanoma cells and their variant gene expression in vitro, a search for specifically regulated genes was performed. Four melanoma cell lines (M5, MEWO, IGR39, SKMEL13) and newly cultured normal human melanocytes were included in a comparative hybridization (differential screening) of a human melanoma cDNA-library. Six cDNAs were isolated showing a stronger expression (four genes) or a weaker expression (two genes) in melanoma cells than in normal human melanocytes. Quantification of the expression patterns of the two repressed genes in Northern blots revealed general expression in all melanocyte cultures examined, no expression in three cell lines (M5, IGR39, SKMEL13) and weak expression in MEWO. The four induced genes were found to be only weakly expressed in normal human melanocytes, but showed an elevated expression in all of the four melanoma cell lines tested. Thus, using the technique of differential screening, consistent gene regulation at the messenger RNA level was identified, which distinguishes the four melanoma cell lines tested from normal melanocytes. We conclude from the expression patterns that specific gene regulation in melanoma cells in vitro is characterized both by strong repression of some melanocyte genes, as well as by the induction of other genes, but there was no indication of new expression of genes specific for melanoma cells. Because of the uniform induction or repression in different melanoma cell lines, it is conceivable that the cloned genes may be involved in the malignant transformation of melanocytic cells.

The effect of two synthetic phospholipids on cell proliferation and phosphatidylcholine biosynthesis in Madin-Darby canine kidney cells

The concentration-dependent effects of two different synthetic phospholipids on cell proliferation and phosphatidylcholine biosynthesis were compared in Madin-Darby canine kidney (MDCK) cells. The alkyllysophospholipid 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine and the alkylphosphocholine, hexadecylphosphocholine, inhibited cell proliferation with half-inhibitory concentrations (IC50) of 75 and 135 mumol/L, respectively. The agents also inhibited phosphatidylcholine biosynthesis in confluent and proliferating MDCK cells. The IC50 of 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine was 40 mumol/L in confluent cells and 20 mumol/L in proliferating cells, whereas the IC50 of hexadecylphosphocholine was higher in both experimental systems (67 mumol/L in confluent cells and 40 mumol/L in proliferating cells). Further experiments revealed that the effect of both agents on phosphatidylcholine biosynthesis was reversible and that the inhibition was mediated by translocation of the rate-limiting enzyme of this pathway, CTP:phosphocholine cytidylyltransferase (EC 2.7.7.15), from membranes to the cytosol, where it is inactive. The present findings suggest that the inhibition of phosphatidylcholine biosynthesis by both synthetic phospholipids might be related, in part, to their antiproliferative effects.

[Contact allergies to corticosteroids. Prevalence, cross-reactions and methods of detection]

Topical corticosteroids (CS) are frequently used to treat of allergic contact dermatitis, so that their own potential for sensitization is rarely detected. However, increasing numbers of hypersensitivity reactions to corticosteroids have been reported during the last 10 years, and allergic skin reactions to over 50 particular compounds have been observed. CS must now be regarded as a rather frequent contact allergen, the prevalence being twice as high in women as in men. Contact allergy to CS is clinically characterized by a chronic and persistent, corticosteroid-resistant dermatitis. In general, hypersensitivity to CS is a type I and/or type IV mediated allergic reaction. Cross-sensitivity between individual corticosteroid preparations has been described owing to their closely related chemical structures (e.g. hydrocortisone and tixocortol pivalate). Contact allergy to CS can be confirmed by patch-tests, intradermal injection tests or application tests; because of the delayed appearance of positive skin reactions a prolonged evaluation period of up to 120 h is recommended. For routine screening the use of the patient's own material and of tixocortol pivalate and budesonide as test marker substances seems appropriate. The development of further marker substances is a target for ongoing research.

[Transformation of multiple basaliomas to squamous cell carcinomas in an HIV patient with Gorlin-Goltz syndrome]

We report on a 32-year-old male patient with Gorlin-Goltz syndrome, who presented with excessive numbers of superinfected basal cell carcinoma. This led us to suspect an underlying HIV infection, which was confirmed by ELISA and Western blotting. Laboratory investigation of the immunological state revealed severe immunosuppression with 267 CD4+ lymphocytes and a CD4/CD8 ratio of 0.3. The histological picture showed multiple basal cell carcinomas, some of them transforming into squamous cell carcinomas. We suspect that the excessive number and the unusual clinical and histological picture of the basal cell carcinomas in this patient were probably influenced by the underlying HIV infection.

Transformation of human keratinocytes is characterized by quantitative and qualitative alterations of the T-16 antigen (Trop-2, MOv-16)

The regulation of synthesis and post-translational processing of the T-16 antigen, a human cell-surface glycoprotein of 50 to 60 kDa, was investigated in normal and transformed human keratinocytes in vitro. Normal keratinocytes of interfollicular and follicular origin were compared with squamous-cell-carcinoma lines, spontaneously immortalized keratinocytes, and SV-40 transformed keratinocytes. FACS analysis and radio-immunoprecipitation showed that the synthesis and expression of T-16 was 3- to 4-fold higher in transformed keratinocytes than in their normal counterparts. In normal keratinocytes, no quantitative differences were observed among freshly prepared cells, primary cultures and sub-cultures. In SDS-PAGE, a single broad band at 50 to 60 kDa was observed in normal keratinocytes, whereas 2 bands at 42 and 45 to 55 kDa were detected after transformation. Tunicamycin treatment of living cells and glycosidase digestion of immunopurified T-16 antigen revealed this molecular heterogeneity to be due to different N-glycosylation in normal and transformed keratinocytes. In pulse-chase experiments, 2 distinct precursor proteins at 38 and 42 kDa were detected in transformed keratinocytes, whereas in normal cells the 38-kDa signal was dramatically decreased. These findings indicate that quantitative and qualitative changes of T-16 mark the transformation process of human keratinocytes, showing similar post-translational alterations in all transformed populations investigated.

Tumour necrosis factors and several interleukins inhibit the growth and modulate the antigen expression of normal human melanocytes in vitro

In the present study the action of various cytokines as regulators of human melanocyte growth and differentiation was examined in vitro. Primary melanocyte cultures were obtained in complete medium free of 12-O-tetradecanoylphorbol-13-acetate or serum. First passage melanocytes were treated with various concentrations of recombinant tumour necrosis factor alpha and beta (rTNF-alpha, rTNF-beta), as well as with various recombinant interleukins (rIL-1a, rIL-1b, rIL-2, rIL-3, rIL-4 and rIL-6) for 6 days in complete medium and for 6 and 12 days in a mitogen-reduced medium variant. The 4-methylumbelliferyl heptanoate fluorometric microassay and Ki-67 staining were used for assessing cell proliferation, and the immunophenotype was evaluated using various monoclonal antibodies. Melanocyte proliferation in complete medium was inhibited by rTNF-alpha (-24%), rTNF-beta (-17%), rIL-1a (-21%), rIL-1b (-18%) and rIL-6 (-29%); in contrast, rIL-2, rIL-3 and rIL-4 had no antiproliferative effect. Measurements of Ki-67-positive nuclei confirmed these results. In the reduced medium variant, none of the above cytokines inhibited melanocyte proliferation. Recombinant TNF-alpha and rTNF-beta markedly reduced the expression of the pigment cell-associated antigens HMB-45 and K.1.2, and they enhanced the expression of VLA-2, ICAM-1 and HLA class I antigens and strongly induced HLA-DR. Similar changes were induced by rIL-1a, rIL-b and rIL-6, and rIL-2 decreased the expression of HLA class I antigens and of ICAM-1. In conclusion, several cytokines inhibited the growth and modulated the phenotype of melanocytes in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal photopheresis--a new approach for the treatment of cutaneous T cell lymphomas

Extracorporeal photochemotherapy (extracorporeal photopheresis, ECP) is going to become a new alternative in the treatment of cutaneous T cell lymphomas (CTCL), autoimmune disorders, and transplant rejections. After the first promising results in the treatment of CTCL reported in 1987 by Edelson et al. increasing numbers of CTCL patients in a growing number of ECP centers throughout the United States, Europe, and Japan have been successfully treated. Today, it seems that in particular Sézary's syndrome and the erythrodermic variant of mycosis fungoides (MF) respond very well to ECP. Compared to historical controls of MF with lymph node involvement, the median survival of the ECP-treated patients increased from 30 months to up to 60 months. It is our experience that the tumor stage of MF, however, cannot be treated with ECP alone, but is successfully controlled by combination regimens, for example with recombinant interferon alpha. CTCL patients heavily pretreated by polychemotherapy and severe endogenous or iatrogenic immunsuppression do not respond sufficiently and are not good candidates for ECP. The adverse reactions under ECP are well controlled and very low in number. In particular, general immunosuppression by ECP has not been reported so far.

Photodynamic action of ultraviolet A: induction of cellular hydroperoxides

Long-wavelength ultraviolet radiation (UVA) can cause cancer. A carcinogenic mechanism involved may be the induction of harmful reactive oxygen species resulting from photodynamic effects. UVA is generally assumed to induce photodynamic effects, but evidence from experiments with viable biological materials has been indirect until present. Here we measured the induction of (lipid) hydroperoxides as direct indicators of photodynamic reactions. Cultured human fibroblasts were irradiated with 10J UVA/cm2. The induced hydroperoxides were measured by an enzymatic method using glutathione peroxidase and glutathione reductase (GR). Additionally, reduced glutathione (GSH) was determined as parameter for the constitutive antioxidant defense. UVA was found to increase lipid hydroperoxides in fibroblasts by 116% (p < 0.001), when compared to nonirradiated controls. Conversely GSH was decreased in the irradiated cells by 51% (p < 0.001). Because of the induced hydroperoxides, it is concluded that the UVA effects were mediated by a photodynamic mechanism. The photodynamic mechanism resulted in the formation of reactive oxygen species and the consumption of constitutive antioxidants. This suggests a role for antioxidants during the photodynamic mechanism. Photodynamic mechanisms may play a crucial role in carcinogenic events, especially after UVA.