Extracorporeal photopheresis of cutaneous T-cell lymphoma is associated with reduction of peripheral CD4+ T lymphocytes

BACKGROUND

Extracorporeal photopheresis (ECP) has been successfully introduced for the treatment of cutaneous T-cell lymphoma; however, the mechanism(s) of its action is (are) unknown.

OBJECTIVE

To investigate the effects of ECP on the immune system of patients with cutaneous T-cell lymphoma.

METHODS

Clinical response and changes of lymphocyte subpopulations in 20 patients with cutaneous T-cell lymphoma under ECP monotherapy or combined regimens were evaluated and compared after 3, 6 and 12 ECP cycles.

RESULTS

Thirteen of 20 patients showed a > or = 50% reduction of skin lesions after 6-12 ECP cycles. An overall T-lymphocyte reduction was assessed with a balanced CD4+ T-helper and CD8+ T-suppressor cell decrease in responders. In contrast, there was a trend of CD4+ T-helper cell increase in nonresponders which could result from the failure of treatment to control the natural course of the disease. The CD4+/CD8+ ratios were 1.6 at baseline and 1.4 after 12 cycles in responders, while they increased from 1.7 to 4.1 in nonresponders, respectively (p = 0.47). In addition, there was an overall decrease in the CD57+/CD8+ T-cell subpopulation mostly due to a reduction in the responder group.

CONCLUSION

The marked differences detected in certain T-cell subpopulations suggest an effect of ECP on peripheral T lymphocytes and, especially, on CD4+ cells.

Oral retinoids in the treatment of seborrhoea and acne

Isotretinoin is an extremely effective drug if given systemically in severe forms of seborrhoea and acne, being the only retinoid with potent sebostatic properties. Its unique activity on the sebaceous gland still remains unclear since isotretinoin barely binds to cellular retinoic-acid-binding proteins and to retinoic acid receptors. Its bioavailability is approximately 25% and can be increased by food 1.5-2 times; after 30 min, the drug is detectable in the blood and maximal concentrations are reached 2-4 h after oral intake. The major metabolites of isotretinoin in blood are 4-hydroxy- and 4-oxo-isotretinoin, while several glucuronides are detectable in the bile. 4-Oxo-isotretinoin is present in plasma in a 2- to 4-fold higher concentration 6 h after a single dose. Steady-state concentrations appear after 1 week. The half-life elimination rate of the parent compound ranges from 7 to 37 h while that of some metabolites does so from 11 to 50 h. Isotretinoin crosses the placenta and is recognized as a strong teratogenic compound. About 10-30% of the drug is metabolized via its isomer tretinoin. Excretion of isotretinoin occurs after conjugation with the faeces or after metabolization with the urine. The epidermal levels of isotretinoin are rather low and no progressive accumulation, either in serum or in the skin, is found. After discontinuation of therapy, isotretinoin disappears from serum and skin within 2-4 weeks. Isotretinoin is the most effective drug in reducing sebaceous gland size (up to 90%) by decreasing proliferation of basal sebocytes, suppressing sebum production and inhibiting sebocyte differentiation in vivo. The molecular basis for its antisebotrophic activity has not been fully elucidated. Isotretinoin also exhibits anti-inflammatory activities. Systemic isotretinoin is today the regimen of choice in severe seborrhoea, since it reduces sebocyte lipid synthesis by 75% with daily doses as low as 0.1 mg/kg after 4 weeks. Patients who have received oral isotretinoin therapy for seborrhoea do not usually experience a relapse for months or years. In severe acne, a 6- to 12-month treatment with isotretinoin 1 mg/kg/day reduced to 0.5 or 0.2 mg/kg/day according to the response is recommended (cumulative dose of > 120 mg/kg). Contraception is essential during isotretinoin treatment in women of childbearing age 1 month before, during and for 3 months after discontinuation of treatment.

The human sebocyte culture model provides new insights into development and management of seborrhoea and acne

Seborrhoea and acne are exclusively human diseases and sebaceous gland differentiation is species specific. Therefore, fundamental research on human sebaceous cell function and control requires human in vitro models. The human sebocyte culture model, introduced in 1989, has been used in several studies to elucidate sebaceous gland activity and its regulation at the cellular level. Cultured human sebocytes have been shown to preserve important sebocytic characteristics, although they undergo an incomplete terminal differentiation in vitro. In vitro synthesis of free fatty acids without bacterial involvement and marked interleukin 1 alpha expression at the mRNA and protein levels with no further induction by lipopolysaccharides lead to the assumption that human sebocytes may initiate acne lesions by an intrinsic mechanism. Androgens affected sebocyte activity in vitro in a manner dependent on the localization of the sebaceous glands. In vitro stimulation of sebocyte proliferation by androgens could be completely abolished by spironolactone. Cultured sebocytes strongly expressed type 1 5 alpha-reductase and metabolized testosterone to androstenedione, 5 alpha-androstanedione, 5 alpha-dihydrotestosterone, androsterone and 5 alpha-androstanediol, whereas the levels of 5 alpha-reductase activity were probably not feedback regulated. 4,7 beta-Dimethyl-4-aza-5 alpha-cholestan-3-one, a type 1 5 alpha-reductase inhibitor, induced an early, marked down-regulation of 5 alpha-reductase activity in human sebocytes in vitro, while hydrofinasteride, a type 2 inhibitor, required 10(3)-fold higher concentrations to induce similar effects. Stimulation of sebocyte proliferation by insulin, thyroid-stimulating hormone and hydrocortisone indicates that the hormonal control of the sebaceous gland could be a complex mechanism. Retinoids inhibited sebocyte proliferation in a dose-dependent manner and down-regulated lipid synthesis and sebocyte differentiation in vitro. Isotretinoin was the most potent compound. On the other hand, vitamin A was found essential for sebocyte activity and differentiation in vitro and could be partially substituted by synthetic retinoids. The inhibitory effect of isotretinoin on sebocyte proliferation was barely affected by the presence of vitamin A. The low persistent isotretinoin levels or, more likely, the considerably elevated tretinoin concentrations detected in human sebocytes after treatment with isotretinoin in vitro may be responsible for the inhibitory effect of this compound on sebocyte activity.

Management of severe scleroderma with long-term extracorporeal photopheresis

BACKGROUND

The management of systemic sclerosis remains unsatisfactory. Thus far, the action of extracorporeal photopheresis (ECP) in severe systemic scleroderma has been evaluated in short-term studies, and only limited experience has been obtained with long-term application.

OBJECTIVE

The aim of the present study was to evaluate prospectively the long-term effect of ECP in a group of 16 patients suffering from severe scleroderma, showing visceral involvement and progressive clinical course.

METHODS

Fourteen patients with systemic scleroderma involving several organs, 1 with CREST syndrome and another with scleroderma-myositis overlap syndrome were treated with ECP over a period of 6-45 months. In 3 cases, gamma-IFN was additionally administered. Skin and visceral involvement were assessed by evaluating a series of clinical criteria and results from laboratory, imaging and functional tests.

RESULTS

Overall, clear improvement was encountered in 6 patients, mixed response in 2, stable disease in 3 and continuing progressive course in 5 patients. Four out of 6 patients with improvement were treated with ECP early after onset of scleroderma (< or = 2 years), whereas all patients with a progressive course under ECP had had scleroderma for longer than 2 years. Immunosuppressive drugs previously administered could be reduced or fully withdrawn under ECP treatment in 5 patients, but additional oral medication was introduced in 4 patients due to disease progression. Addition of gamma-IFN to ECP did not reveal further benefit. No side-effects were recorded under ECP treatment.

CONCLUSIONS

Based on this observation, we believe that long-term ECP represents an effective treatment modality in severe scleroderma particularly when started early, with stabilization of the disease course and partial remission of the cutaneous findings, whereas visceral involvement, if present, may rarely improve.

Polymorphisms in the human cytochrome P-450 1A1 gene (CYP1A1) as a factor for developing acne

Cytochromes P-450 are a supergene family of enzymes involved in the metabolism of a wide range of endogenous and foreign compounds. The existing genetic variations of the distinct isozymes lead to interindividually different metabolic capacity. Since vitamin A, endogenous retinoids and their natural metabolites are morphogenic for the sebaceous gland, we investigated the polymorphisms of cytochrome P-450 1A1, as being one of the most active isozymes involved in their interconversion. From the known mutations, two were investigated; an additional cleavage site for MspI in the 3'-flanking region identified as a thymine-to-cytosine transition 1,194 bp downstream of exon 7 (m1) and an adenine-to-guanine transition at position 4889 in exon 7 (m2). We studied 96 acne patients for m1 and m2 mutations by restriction fragment length polymorphism and allele-specific polymerase chain reaction, respectively, and compared the results with 408 reference individuals. No statistically significant difference was found in the distribution of m2 alleles; the frequency was 3.13 and 3.06% of the alleles, respectively (odds ratio = 1.02, confidence limits 0.41-2.52, p = 0.96). In contrast, a trend to an overrepresentation of m1 alleles in acne patients was observed; allele frequency was 8.33 in the patients and 6.99% in the control subjects, respectively (odds ratio 1.21, 95% confidence limits 0.68-2.16, p = 0.52). As the m1 mutation might define a marker for alterations on regulatory sites, the biological efficacy of natural retinoids could be greatly impaired by their rapid metabolism to inactive compounds. The resulting deficit of active natural retinoids may lead to abnormal sebocyte differentiation and hyperkeratinization of the follicular canal implicating the development of acne in some patients.

Monitoring of isotretinoin therapy by measuring the plasma levels of isotretinoin and 4-oxo-isotretinoin. A useful tool for management of severe acne

BACKGROUND

Isotretinoin for oral therapy in severe acne conglobata and acne nodulocystica represents a significant achievement; however, the drug exerts several mucocutaneous and systemic adverse effects, besides its teratogenic potency.

OBJECTIVE

The aim of this study was to investigate the plasma levels of isotretinoin and of 4-oxo-isotretinoin over long-term treatment of severe acne and to assess any correlation with the given dose, the clinical improvement and the occurrence of side effects.

METHODS

Forty-one patients with severe acne and acne-related disorders were studied under long-term oral intake of isotretinoin. Therapeutic effects and side effects were evaluated prior, during and at the end of therapy. The plasma levels of isotretinoin and of its major metabolite 4-oxo-isotretinoin were measured by reversed-phase HPLC and were correlated with the administered oral dose and the number and frequency of side effects.

RESULTS

Dose-dependent plasma levels of isotretinoin and its metabolite were observed. At a mean dosage of 0.75-1.0 mg/kg/day, 404 +/- 142 ng/ml were measured, whereas the plasma levels of 4-oxo-isotretinoin were 1-2x higher. The plasma levels correlated well with the orally administered dose of isotretinoin and the observed mucocutaneous side effects.

CONCLUSION

The study demonstrates that measuring of the plasma levels may be a helpful tool to monitor the individual therapeutic dose regimen in patients with severe acne in order to minimize undesired side effects and to control oral intake.

Melkersson-Rosenthal syndrome in childhood: a challenge in differential diagnosis and treatment

Facial palsy and orofacial swelling in childhood represent a challenge in differential diagnosis for paediatricians and dermatologists. One possible entity, Melkersson-Rosenthal syndrome (MRS), is a rarity in childhood. We describe a 9-year-old girl with the diagnosis of MRS who had episodic swelling of the upper lip and complete peripheral facial palsy, associated with herpes and recurrent bacterial infections. Therapeutic options for MRS in childhood are limited. Our patient benefited from a 2-month course of prednisolone 1 mg kg(-1) daily. We review previously published cases of MRS in childhood, and discuss the differential diagnosis of orofacial swelling and facial palsy as well as treatment options in children.

Bcl-2 transfected HaCaT keratinocytes resist apoptotic signals of ceramides, tumor necrosis factor alpha and 1 alpha, 25-dihydroxyvitamin D(3)

During the last few years increasing evidence has shown that sphingolipid metabolites are highly bioactive compounds that play important roles in cellular regulation. The induction of ceramide signalling in primary human keratinocytes and HaCaT keratinocytes has recently been demonstrated using 1 alpha,25-dihydroxyvitamin D(3). The data obtained indicate that approximately one-third of the proapoptotic effect of 1 alpha,25-dihydroxyvitamin D(3) is mediated by an intracellular ceramide increase induced via tumor necrosis factor. expression and autocrine stimulation of sphingomyelin hydrolysis. In the present study the role of bcl-2 in this process was investigated. HaCaT keratinocytes were transfected with bcl-2 and the effects of C(2)-ceramide, tumor necrosis factor alpha and 1 alpha,25-dihydroxyvitamin D(3) on HaCaT keratinocytes stably overexpressing bcl-2 were determined. Apoptosis was measured by detection of soluble DNA-histone complexes using the ELISA technique. In situ analysis of apoptotic cells was also carried out by detecting phosphatidylserine flip using the annexin V method and by detecting DNA fragmentation using the TUNEL assay. The results obtained showed that apoptosis induced by C(2)-ceramide, tumor necrosis factor alpha or 1 alpha,25-dihydroxyvitamin D(3) occurred in a vector-transfected clone but not in a bcl-2-transfected HaCaT clone. This indicates the important role of bcl-2 in the regulation of ceramide-mediated signalling pathways in human keratinocytes and supports the involvement of ceramide as a signalling molecule in 1 alpha,25-dihydroxyvitamin D(3)-induced biological responses.

[Antibiotic susceptibility of Neisseria gonorrhoeae isolates in Berlin]

BACKGROUND AND OBJECTIVE

Because of the increasing resistance of Neisseria gonorrhoeae, we studied the actual resistance of isolates in Berlin.

PATIENTS/METHODS

85 Neisseria gonorrhoeae isolates were collected between 1995 and 1997. Susceptibility testing was performed for penicillin G, tetracycline, spectinomycin, ceftriaxone, ciprofloxacin and azithromycin by agar dilution.

RESULTS

18.8% isolates were resistant or intermediately resistant to penicillin G (including 6 PPNG). 12.9% isolates were resistant, 43.5% intermediately resistant to tetracycline. One strain was resistant against ciprofloxacin, 4 isolates showed increased MIC values (0.06-0.5 mg/l), whereas 78 isolates were fully susceptible (< 0.007 mg/l). All isolates were susceptible to spectinomycin, ceftriaxone, and azithromycin.

CONCLUSIONS

Penicillin G and tetracycline should be given only in cases of proven sensibility. Resistance against ciprofloxacin may occur, especially in isolates acquired in south-east Asia. Ceftriaxone, spectinomycin and azithromycin were active against all isolates. The actual resistance situation should be monitored.

Cutaneous mastocytosis in adults. evaluation of 14 patients with respect to systemic disease manifestations

BACKGROUND AND OBJECTIVE

Systemic mastocytosis is a rather rare disorder involving the skin and several other organs. The aim of this study was to analyse the extent of extracutaneous manifestations in 14 adult patients who presented with prominent cutaneous involvement within the last 5 years.

RESULTS

The cutaneous lesions were clinically diagnosed as telangiectasia macularis eruptiva perstans in 2 patients, urticaria pigmentosa of varying extent in 11 and diffuse erythrodermic mastocytosis in 1 patient. All patients had extracutaneous manifestations with involvement of one additional organ system in 6/14 cases, two in 5/14 and three in 3/14. Ten out of 14 patients suffered from generalized pruritus, and 11/14 reported mild wheal formation, while 3/14 with multi-organ involvement mentioned recurrent flushing episodes. The gastro-intestinal tract was involved in 8/14 cases with an increase in gastric and colon mucosal mast cells in 5/8 cases and gastroduodenitis in 2. Bone marrow involvement was seen in 7/13 patients, hepatosplenomegaly in 2, anaemia in 2 and thrombocytopenia in 3. The disease had a duration of 0.5-32 years, clinical symptoms remaining basically unchanged. Malignant transformation was not seen; only 1 patient developed myelodysplastic syndrome within 2 years after the first cutaneous lesions.

CONCLUSIONS

Our study shows that extracutaneous involvement should be carefully considered in adult patients with cutaneous mastocytosis. Systemic multi-organ mast cell disease in adults is a long-lasting disorder with recurrent episodes of varying clinical symptomatology. However, the disease shows rather slow progression, and malignant transformation is rare. Satisfactory management is achieved by symptomatic oral drug intake.

[Livedo racemosa: an unusual late manifestation of borreliosis?]

Classic variants of cutaneous borreliosis are erythema chronicum migrans (ECM), lymphadenosis benigna cutis (LBC) and acrodermatitis chronica atrophicans (ACA). Other dermatoses have been reported in the literature as possibly linked to borreliosis. A 59-year old female patient was seen in the late phases of cutaneous borreliosis with histologically confirmed ACA. In addition, prominent livedo racemosa was seen on the legs, also showing tissue changes similar to those of ACA. Borrelia burgdorferi infection was serologically confirmed by the presence of anti-IgM and anti-IgG antibodies. The clinical spectrum of late cutaneous borreliosis should be enlarged to include livedo racemosa.

Guess what! Eruptive vellus hair cysts

An otherwise healthy 24-year-old woman presented with persistent asymptomatic skin-coloured papular lesions on her trunk which had appeared over 18 months, gradually increasing in number, size and the extent of the skin surface area involved. Physical examination revealed multiple flesh - to whitish - coloured papules, 2 to 5 mm in diameter, located on her neck, anterior chest wall, axillae and upper abdomen (Fig. 1). The lesions were smooth, painless on palpation and not grouped. Laboratory investigations only showed normal results. Histopathological examination of a papular lesion from the upper abdomen revealed a cystic structure in the mid-dermis lined by four to five layers of squamous epithelium with a discrete granular layer. Laminated keratinous material and multiple transversely or obliquely cut vellus hairs were present within the cyst, while sebaceous elements were lacking in the vicinity or within the cyst wall (Fig. 2a, b). Polaroscopic examination demonstrated double refractile vellus hairs in the cyst.

13-cis retinoic acid exerts its specific activity on human sebocytes through selective intracellular isomerization to all-trans retinoic acid and binding to retinoid acid receptors

Despite its potent biologic effect on human sebocytes, 13-cis retinoic acid exhibits low binding affinity for cellular retinoic acid binding proteins and nuclear retinoid receptors. Hence, 13-cis retinoic acid may represent a pro-drug possibly acting through all-trans isomerization. In this study, marked isomerization of 13-cis retinoic acid has been confirmed in cultured SZ95 sebocytes showing 2- to 15-fold higher levels of all-trans retinoic acid at 12-72 h, as measured by high performance liquid chromatography. In contrast, only low amounts of all-trans retinoic acid were converted intracellularly to its 13-cis isoform. 9-cis retinoic acid was not detected after either 13-cis retinoic acid or all-trans retinoic acid treatment. The rapid isomerization of 13-cis retinoic acid to high levels of all-trans retinoic acid was a sebocyte-specific event, as no significant isomerization of 13-cis retinoic acid to all-trans retinoic acid occurred in HaCaT keratinocytes. De novo mRNA expression of cytochrome P450 1A1, a major xenobiotic metabolizing enzyme, in SZ95 sebocytes was induced by all-trans retinoic acid, but not by 13-cis retinoic acid. In addition, mRNA levels of cellular retinoic acid-binding protein II, which is supposed to regulate the concentration of intracellular all-trans retinoic acid, rapidly increased under all-trans retinoic acid treatment (30 min-6 h), whereas the 13-cis retinoic acid effect was markedly weaker and delayed. Both 13-cis retinoic acid and all-trans retinoic acid suppressed mRNA expression of cytochrome P450 1A2. In parallel experiments, 13-cis retinoic acid significantly reduced SZ95 sebocyte proliferation at 10-7 M, show- ing 30-40% inhibition after 9 d. All-trans retinoic acid and 9-cis retinoic acid exhibited similar anti-proliferative effects. AGN 193109, a pan-antagonist of the retinoic acid receptors, antagonized the anti-proliferative activity of all retinoic acid isomers tested in a concentration-dependent manner with complete abolishment at ratios of 1:10 13-cis retinoic acid and 1:1 all-trans retinoic acid. Coincubation of SZ95 sebocytes with 13-cis retinoic acid and AGN 193109 did not alter the intracellular concentration of 13-cis retinoic acid and its isomerization profile. In contrast, the retinoid X receptor antagonist CD 3507 did not affect the inhibition of SZ95 sebocyte proliferation induced by retinoic acids. Our findings indicate: (i) a selective 13-cis retinoic acid isomerization to all-trans retinoic acid in the intracellular compartment of SZ95 sebocytes; (ii) a reduced all-trans retinoic acid inactivation process after 13-cis retinoic acid treatment as compared with treatment with all-trans retinoic acid; and (iii) a retinoic acid receptor-mediated inhibition of SZ95 sebocyte proliferation. These data explain the sebocyte-specific activity of 13-cis retinoic acid and support a pro-drug/drug relation between 13-cis retinoic acid and all-trans retinoic acid.

High detection rate of T-cell receptor beta chain rearrangements in T-cell lymphoproliferations by family specific polymerase chain reaction in combination with the GeneScan technique and DNA sequencing

The distinction between benign polyclonal and malignant monoclonal lymphoid disorders by morphology or immunophenotyping is frequently difficult. Therefore, the demonstration of clonal B-cell or T-cell populations by detecting identically rearranged immunoglobulin (Ig) or T-cell receptor (TCR) genes is often used to solve this diagnostic problem. Whereas the detection of rearranged Ig genes is well established, TCR gamma (gamma) and beta (beta) gene rearrangements often escape detection with the currently available polymerase chain reaction (PCR) assays. To establish a sensitive, specific, and rapid method for the detection of rearranged TCR-beta genes, we developed a new PCR approach with family-specific Jbeta primers and analyzed the resulting PCR products by high-resolution GeneScan technique. The superior efficiency of this new method was demonstrated by investigating 132 DNA samples extracted from lymph node and skin biopsy specimens (mostly formalin fixed) and blood samples of 62 patients who had a variety of T-cell lymphomas and leukemias. In all but 1 of the tumor samples (98.4%) a clonal amplificate was detectable after TCR-beta PCR and the same clonal T-cell population was also found in 15 of 18 (83%) of the regional lymph nodes and in 7 of 11 (64%) of the peripheral blood samples. Direct comparison of these results with those obtained currently by the most widely applied TCR-gamma PCR revealed an approximate 20% lower detection rate in the same set of samples than with the TCR-beta PCR method. These results indicate that the new TCR-beta PCR is most suitable for a rapid and reliable detection of clonal T-cell populations. (Blood. 2000;96:640-646)

Adamantiades-Behçet's disease: interleukin-8 is increased in serum of patients with active oral and neurological manifestations and is secreted by small vessel endothelial cells

The serum levels of several cytokines were determined in 94 patients with Adamantiades-Behçet's disease (ABD), aged 36.1+/-11.0 years, during the active stage (n = 75) and the inactive stage (n = 19) of the disease. A group of 75 healthy individuals matched for age and sex served as controls. Cytokine levels were determined using commercially available ELISA kits. Of the 75 patients with active disease and 19 with inactive disease, 38 (51%) and 4 (21%), respectively, and 23 healthy controls (31%) were found to have detectable levels of interleukin 8 (IL-8) in their serum (P < 0.05). Also, increased IL-8 serum levels were found in patients with active disease (median 12 pg/ml, P = 0.010) compared to patients with inactive disease (< or = 10 pg/ml) and to healthy controls (< or = 10 pg/ml). In particular, patients with oral aphthous ulcers (n = 51, 34 pg/ml) and neurological features (n = 4, 71 pg/ml) exhibited increased IL-8 levels. In contrast, there was no correlation between disease activity and the serum levels of IL-1alpha, IL-1beta, tumor necrosis factor alpha (TNF-alpha), soluble intercellular adhesion molecule-1 or basic fibroblast growth factor (bFGF). In a second set of experiments, the involvement of dermal microvascular endothelial cells in IL-8 secretion was investigated. Immortalized human dermal microvascular endothelial cells (HMEC-1 cells) were maintained for 4 h in vitro with serum from 18 ABD patients or with IL-1beta, a known stimulator of IL-8 synthesis, TNF-alpha or their combination at five- to tenfold higher concentrations than those found in the serum of ABD patients. Increased IL-8 secretion was found after incubation with ABD patients' serum (median 20 pg/ml), but IL-1beta, TNF-alpha and IL-1beta + TNF-alpha failed to induce IL-8 secretion by HMEC-1 cells (< or = 1-1.2 pg/ml) in biologically relevant concentrations. Our study showed increased IL-8 serum levels in ABD patients with active oral and neurological manifestations. Human microvascular endothelial cells may, at least partially, be responsible for the enhanced IL-8 secretion in the active stage of the disease.

Alternative versus classical activation of macrophages

In parallel to the Th1/Th2 paradigm, antigen-presenting cells (APC) are divided into classically activated APC (dendritic cells/effector macrophages) and alternatively activated APC (IL-4-induced, alternatively activated macrophages/IL-10-induced, immature dendritic cells). Alternatively activated APC share a special molecular repertoire including receptors of innate immunity with broad specificity for foreign antigen and anti-inflammatory cytokines such as IL-1Ra and alternative macrophage activation-associated CC-chemokine-1. Alternatively activated APC mediated tolerance and downregulated inflammation. Abuse of alternatively activated APC in support of infectious susceptibility or tumor immune escape is counteracted by the classical pathway. Thus, classically and alternatively activated APC secure the balance between proinflammatory and anti-inflammatory immune reactions.

Resistance to CD95/Fas-induced and ceramide-mediated apoptosis of human melanoma cells is caused by a defective mitochondrial cytochrome c release

Intracellular CD95/Fas-signaling pathways have not been investigated in melanoma yet. Two different CD95 receptor-induced apoptotic pathways are presently known in other cell types: (i) direct activation of caspase-8 and (ii) induction of ceramide-mediated mitochondrial activation, both leading to subsequent caspase-3 activation. In the present study, five of 11 melanoma cell populations were shown to release cytochrome c from mitochondria, which activates caspase-3 and finally results in DNA fragmentation upon treatment with the agonistic monoclonal antibody CH-11. In contrast, this apoptotic pathway was not activated in the remaining six melanoma cell populations. Interestingly, the susceptibility of melanoma cells to CD95L/FasL-triggered cell death was clearly correlated with N-acetylsphingosine-mediated apoptosis. Our results are in line with a defect upstream of mitochondrial cytochrome c release in resistant cells.

Multiple familial cutaneous glomangioma: a pedigree of 4 generations and critical analysis of histologic and genetic differences of glomus tumors

BACKGROUND

Glomangiomas are benign tumors arising from neuromyoarterial cells surrounding cutaneous arteriovenous anastomoses that serve as temperature regulators. They exist as solitary or multiple types, occurring sporadically or in a familial pattern, the latter of which is rare.

OBJECTIVE

We describe a 4-generation pedigree of familial cutaneous glomangioma, in addition to the 3 other well-documented pedigrees reported in the literature to date, and we clarify ways in which to distinguish the different types of glomus tumors.

METHODS

Nodular skin lesions of 4 affected family members were analyzed by histologic, immunohistologic, and electron microscopic methods. To elucidate the gene defect in this family, we searched for a linkage to a candidate locus on chromosome 11q23 previously identified in paragangliomas, one form of glomus tumor, in 16 family members of 4 generations by using polymorphic markers.

RESULTS

The diagnosis of disseminated cutaneous glomangiomas was confirmed histologically in 4 family members of 3 different generations. Glomangiomas were transmitted in an autosomal dominant pattern via the paternal line. Genetic linkage analysis of the affected family members excluded linkage to chromosome 11q23.

CONCLUSION

An autosomal dominant pattern of inheritance has been described for glomus tumors of the paraganglioma type originating from the APUD cell system, the underlying genetic defect of which has been mapped to chromosome 11q23. In contrast, we show that the genetic defect in disseminated cutaneous glomus tumors of the glomangioma type deriving from smooth muscle cells or pericytes is not linked to chromosome 11. Thus we suggest that the common term glomus tumor, used for both paragangliomas and glomangiomas in the current literature, is misleading and should be avoided because these tumors have different histologic derivation and genetic origin.

Cerebriform nodular amelanotic metastases of malignant melanoma: a challenge in differential diagnosis of a rare variant

High variability of the clinical appearance of malignant melanoma (MM) and its metastases render the differential diagnosis of solid amelanotic tumours difficult. We report a 71-year-old woman with several unusual cutaneous tumours of cerebriform morphology, suggesting skin metastases from occult internal cancer. Histopathological findings and thorough investigations, however, revealed a late-stage metastatic MM. We discuss the differential diagnosis of skin metastases of various origin and underline the difficulties for early detection of MM.

Pseudoexons and regulatory elements in the genomic sequence of the beta-chemokine, alternative macrophage activation-associated CC-chemokine (AMAC)-1

Recently, the authors reported the cloning of a novel human CC chemokine of alternatively activated macrophages (AMAC-1), whose expression is induced by Th2-associated cytokines such as interleukin 4 (IL-4), IL-13 and IL-10; vice versa, AMAC-1 expression is inhibited by Th1-associated cytokines such as interferon gamma (IFN-gamma). In order to study the genomic organization and transcriptional regulation of the AMAC-1 gene, genomic clones were isolated by screening a human lambda genomic library. Sequencing of a clone with a 1.7-kb insert gave a partial genomic sequence for the AMAC-1 gene. The complete AMAC-1 genomic sequence was obtained by bioinformational methods and the whole region spanning the AMAC-1 gene was verified by PCR amplification of subfragments and sequencing. The AMAC-1 gene consists of three exons. Whereas exons 2 and 3 were separated by a small intron of 411 bp, exon 1 and exon 2 were separated by 6 kb of non-translated genomic sequence containing two pseudoexons that are not expressed although they feature intact exon/intron boundaries and complete open reading frames. In order to allow a detailed analysis, a 2.7-kb fragment containing the promoter region and the first exon of AMAC-1 gene was cloned into a reporter gene construct. In the AMAC-1 promoter, two possible transcription start points were identified. In addition, several putative regulatory sequences for IL-4- and IFN-gamma-dependent transcriptional pathways were found including STAT6 and STAT1 binding sites as well as several AP-1 and C/EBP elements. Interestingly, a combined STAT6/STAT1 binding element is located in the direct vicinity of the first putative transcription start point. Competitive binding of IL-4-induced STAT6 versus IFN-gamma-induced STAT1 to this site may explain the antagonistic effects these cytokines exert on AMAC-1 expression.

Increase in sensitization to oil of turpentine: recent data from a multicenter study on 45,005 patients from the German-Austrian Information Network of Departments of Dermatology (IVDK)

Contact allergy to oil of turpentine was reported to have become rare. However, the evaluation of standardized data of 45,005 patients tested 1992-1997 in 30 Dermatological Centers associated with the German-Austrian Information Network of Departments of Dermatology (IVDK) showed an increase in positive patch test reactions to turpentine from 0.5% during the years 1992-1995, up to 1.7% in 1996 and 3.1% in 1997. In particular, 17,347 patients tested in 1996-1997 were evaluated in detail by comparing 431 individuals with positive patch test reactions with the rest of the group found negative to turpentine. Using the so-called MOAHLFA index, the following characteristics were shown. Turpentine allergy (a) was found to be significantly less frequent in men and in patients with occupational dermatitis, (b) showed no difference in its association with atopic dermatitis, (c) patients with turpentine allergy had significantly less symptoms of the hands, more symptoms of the legs or in the face and (d) were significantly more often aged over 60 years. Also, patients sensitized to turpentine had increased rates of additional sensitizations. The definite reason for the increase in turpentine sensitization in the population tested here is not clear. Therefore, a detailed exposure analysis is necessary; the new increase in turpentine allergies may be due to popular topical remedies or household chemicals.

Different vitamin D analogues induce sphingomyelin hydrolysis and apoptosis in the human keratinocyte cell line HaCaT

Sphingomyelin hydrolysis seems to be a ubiquitous pathway generating ceramide, an important cell response modifier. Upon agonist-stimulation this pathway is linked to biological responses as inhibition of proliferation, promotion of differentiation and induction of apoptosis. One of the agonists described is 1alpha,25-dihydroxyvitamin D3. Recently, we could demonstrate the existence of sphingomyelin hydrolysis in human primary keratinocytes as well as in the human keratinocyte cell line HaCaT after treatment with 1alpha,25-dihydroxyvitamin D3. In the present study we tested four vitamin D analogues on HaCaT keratinocytes for their ability to inhibit cell proliferation and to induce sphingomyelin hydrolysis. These analogues, calcipotriol, EB 1213, GS 1500 and tacalcitol inhibit cell growth after 48 hrs. of incubation and trigger the hydrolysis of sphingomyelin. Moreover, all analogues tested induce apoptotic cell death in HaCaT keratinocytes after 24 hrs. of incubation. This study indicates that sphingomyelin hydrolysis, subsequently leading to the elevation of cellular ceramide levels, may represent an important signal transduction pathway for 1alpha,25-dihydroxyvitamin D3 and its analogues in human keratinocytes. Possible differences of the mechanism underlying vitamin D-induced sphingomyelin hydrolysis has to be studied in more detail and may contribute to the antipsoriatic action of these analogues.