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In 1956 Klingmüller first described the trichorhinophalangeal syndrome (TRPS), which was named by Giedion ten years later. The syndrome includes a combination of typical hair, facial and bone abnormalities with variable expression allowing the further distinction of three subtypes. In a 37-year old patient with TRPS type I who reportedly had reduced hair growth length, clinically fine and brittle hair were found. Scanning electron microscopy revealed widely spaced cuticular scales. Quantitative measurement of the biomechanical properties of the hair showed a significant increase in the viscous parameter. This could be a result of decreased disulfide bridges and increased halogen bonds in the keratin matrix of the hair. In dermatological practice patients with TRPS often present because of hair abnormalities. Because of premature arthrosis due to skeletal abnormalities, occupational counseling is advised.Congenital heart problems, kidney abnormalities and endocrinological problems are rare, but should be sought in the symptomatic individual. Apart from mild hair care and avoidance of additional physical or chemical injuries due to hair cosmetic procedures,there is no treatment for the hair defects.

The aim of the present study was to investigate the influence of three different retinoids, isotretinoin, etretinate and acitretin, on the mitogenic response of peripheral blood mononuclear cells (PBMCs) to PHA and PMA in vitro. All three retinoids at high concentrations (10(-4)M) significantly inhibited the mitogenic response of PBMCs to these mitogens. At lower concentrations (10(-5) M and 10(-6) M) none of the three retinoids had any effect on PBMC proliferation in response to PHA. Interestingly, isotretinoin and etretinate significantly enhanced the PMA-induced stimulation of proliferation, whereas acitretin at 10(-5) M failed to influence the mitogenic response to PMA but enhanced it at 10(-6) M. The enhancing effects of retinoids on the proliferative response of PMA-stimulated PBMCs were reversed by rapamycin (10 ng/ml), an immunosuppressant known to inhibit the phorbol ester-induced protein kinase C pathway of lymphocyte activation. In conclusion, our study indicates that retinoids directly trigger the PMA-induced protein kinase C pathway of lymphocyte activation in a concentration-dependent manner. This observation could explain the findings of previous studies showing an in vivo immunopotentiating effect of retinoids on certain immune functions.

The influence of UVA and UVB irradiation of the skin for 1, 2 and 4 weeks on the activities of the hepatic and cutaneous P450 isoenzymes was investigated in female Wistar rats before and after systemic administration of hexachlorobenzene (HCB), a well-known porphyrogenic agent, which additionally induces P450 1A1 and P450 1A2 isoenzymes. UVA and UVB irradiation of the skin of controls and HCB-treated animals did not influence porphyrin metabolism. In the nonporphyric rats hepatic EROD (P450 1A1) activity was induced by UVB, but the activity of ADM (P450 2B) and EMDM (P450 3A) was either minimally or not affected. In the HCB-treated (porphyric) rats UVA and UVB irradiation resulted in a significant depression of HCB-induced EROD in the liver and in the skin. In both the nonporphyric and the porphyric rats UVA and UVB irradiation had no effect on hepatic ADM activity. In the liver of the nonporphyric animals EMDM activity remained unchanged after UVA and UVB irradiation, whereas in the HCB-treated animals the activity of this enzyme was increased. Finally, after UVA and UVB irradiation cutaneous EMDM activity was increased in the controls, whereas the HCB-induced increase of this enzyme in porphyric animals was decreased. In addition long-term (28 days) UVB irradiation decreased hepatic GSH content significantly in normal and porphyric rats. These experimental findings cannot be directly extrapolated to humans; however, they suggest that exposure of human skin to UV radiation may result in alterations in the activity of cutaneous hepatic and other extracutaneous P450 isoenzymes.

We describe the molecular characterization of a novel, in-frame deletion that is located in exon 7 of the alpha-galactosidase A gene in a patient with Fabry's disease. The 3-bp deletion we identified, besides the typical severe clinical features, also expresses diffuse facial telangiectasias, which is a new cutaneous marker of Fabry's disease.

The histological similarities of seborrhoeic keratoses and common warts led to the investigation of the possible occurrence of human papillomavirus DNA (HPV-DNA) in a large number of nongenital seborrhoeic keratoses using the in situ hybridization technique. All specimens derived from normal skin (n = 173) were negative for the applied HPV-DNA probe, whereas the HPV genome was detected in 34 of 173 seborrhoeic keratosis specimens (19.65%). Of 34 HPV-positive specimens, 15 contained types 6/11 and 14 types 31/33/35, and 5 showed no positive reaction to the applied types. These results suggest that a considerable percentage of nongenital seborrhoeic keratoses may be related to an HPV infection.

Oral administration of isotretinoin (13-cis-retinoic acid) (6 mg/kg per day), 0.05% hexachlorobenzene (HCB) or both drugs simultaneously for 10 days to female Wistar rats caused a statistically significant induction of aminopyrine-N-demethylase (ADM), 7-ethoxyresorufin-O-deethylase (7-ERO-D) and erythromycin-N-demethylase (EMDM) in the liver microsomes. Oral administration of isotretinoin alone or together with HCB induced a marked induction of 7-ERO-D and EMDM in the skin. Administration of isotretinoin alone for 60 days resulted in the induction of EMDM in the liver microsomes, and in combination with HCB caused a statistically significant induction of all hepatic isozymes. HCB alone caused a marked induction of only 7-ERO-D in the skin. These results clearly show that oral isotretinoin is capable of inducing hepatic and cutaneous microsomal P-450-dependent catalytic activities. It remains to be elucidated whether the induction of these enzymes is of importance for the therapeutic action of isotretinoin.

Adult female Wistar rats (n = 48) divided into four groups of 12 were treated orally with 3 mg/kg per day thalidomide, a 0.05% hexachlorobenzene (HCB)--containing diet, with both drugs together and with the vehicles (controls) over periods of 10 and 60 days. The protein and P450 contents and the activities of aminopyrine-N-demethylase (ADM) and 7-ethoxyresorufin-O-deethylase (7-ERO-D) were determined in the liver microsomes. The activity of 7-ERO-D was also determined in the skin microsomes and total porphyrins were measured in the urine of the animals. Thalidomide increased the hepatic P450 content, caused distinct changes in the activities of the hepatic and cutaneous microsomal isozymes, modified their induction by HCB and inhibited the porphyrogenic activity of HCB. These findings indicate an interaction between thalidomide and HCB with regard to their effects on the P450 isozymes and the metabolism of porphyrins.

In two female psoriasis patients, curling and kinking of the scalp hair developed subsequent to a long-term etretinate therapy. Scanning electron microscopic examination of kinking hair revealed twists with sharp-edged defects and splitting of the cuticle cells in several hairshafts. The quantitative determination of the mechanical parameters of these hairs using a computerized system revealed statistically significant changes from the pattern in the scalp hair of untreated psoriasis patients. This finding suggests etretinate-induced alteration of the expression of the psoriatic phenotype in the keratin composition of hair in psoriasis patients.

Forty-one male guinea pigs were treated orally with high doses of aromatic retinoid (Ro 10-9359) 25 mg/kg/day in oleum arachidis for 6 weeks. Twenty-three animals were investigated at the end of this treatment. The remaining 18 animals were investigated after an additional retinoid-free interval of 6 weeks. A control group of 13 animals received oleum arachidis only. The histological investigation of the testes of the 23 animals studied immediately after the 6-week application of retinoid revealed reduced diameters of the seminiferous tubules, disorganization and desquamation of the seminiferous epithelium with decreased spermatogenetic activity and lack of mature elements. On the other hand, the 18 animals which were investigated 6 weeks after completion of retinoid treatment did not show any alterations, as compared to the control animals. Our results show that high systemic doses of aromatic retinoid clearly induce impairment of the spermatogenesis; however, all changes were reversible within 6 weeks after withdrawal of the drug.

Oral retinoids have been largely introduced in the management of psoriasis. The beneficial effect, however, differs according to the clinical type and requires an appropriate dosimetry: Pustular types respond rapidly and sufficiently to high initial doses (75 mg/d). In psoriatic erythroderma low initial doses (35 mg/d) seem indicated increasing the dose to 50 mg/d after 2-4 weeks. In chronic stationary psoriasis medium doses (50 mg/d) should be given as adjuvant treatment, combined with anthralin or UVB (SUP). In severe cases oral retinoids can be administered with systemic PUVA (RePUVA). Cheilitis, mucosal dryness and hair loss may appear temporarily as dose dependent side-effects. No hepatotoxicity was found. Interactions with serum triglycerides were seen, particularly in patients with diabetes, obesity, alcoholism and elevated triglyceride levels before treatment. Beside the compound Ro 10-9359 new synthetic derivatives are under investigation, either for topical therapy (Ro 11-1430), or for systemic therapy in lower doses (Ro 12-7554). Their mechanisms of action are still unknown. New findings suggest that retinoids may exert an immunomodulatory effect on dermal cells, in addition to their influence on keratinocytes.

The phospholipid pattern of the involved and the uninvolved epidermis from 48 psoriatic patients and of the normal epidermis from 23 healthy controls was determined by thin-layer chromatography. A higher amount of total phospholipids was found only in the involved psoriatic epidermis, whereas significant alterations in the phospholipid pattern were observed in the psoriatic lesion and in the lesion-free epidermis. Namely, the decrease of phosphatidylserine and the increase of phosphatidylinositol were identically present in both the involved and the uninvolved psoriatic epidermis. It seems likely that these alterations in the phospholipid pattern in psoriasis may be related to subclinical alterations of the epidermis in this disease.

Doses of 3 mg/kg Ro 10-9359 (in arachis oil) were daily administered to adult female Wistar rats by gastric tube for a period of 10 days. Control animals received corresponding quantities of arachis oil only. The body weight of all rats was registered daily. Samples of jejunum and ileum were processed for quantitative histochemical analysis of neutral alpha-glucosidase kinetics and for three-dimensional evaluation of the mucosal architecture. In addition, mucosal scrapings were prepared from these intestinal segments, and the specific sucrase activity was determined. For each animal data were pooled and analyzed by Wilcoxon (Wn) test. Body weight and all registered parameters in the jejunum of treated animals remained unchanged as compared to the controls. In the ileum, however, we found under aromatic retinoid an increase of sucrase activity (P = 0.02) and of mucosal surface per unit serosal area (P less than 0.05). The hydrolytic activity of neutral alpha-glucosidase (Vmax) showed a clear trend to increase at both the villus base and apex, whereas the apparent substrate affinity (Km) remained unaltered. Our results show that, in closes of 3 mg/kg/day, aromatic retinoid induces (1) an increase in mucosal surface area, apparently due to hyperproliferation of the absorptive epithelium in ileum, which could facilitate its absorptive capacity and (2) an increase of specific sucrase activity, which could result in an enhanced carbohydrate assimilation. These findings indicate that Ro 10-9359 in addition to its effects on keratinizing epithelia exerts a distinct influence on the structure and function of the intestinal epithelium.

The effect of oral aromatic retinoid Ro 10-9359 in a high dosage (25 mg/kg/day) on guinea pig epidermis was investigated by light and electron microscopy. The induced morphological alterations showed two different stages: (a) In the injury stage, seen aftr one week of retinoid administraion, the epidermis was mainly characterized by lack of the horny layer and vacuolar cytoplasmic disintergration of the malpighian layer with intracellular edema and accumulation of some PAS-positive material. Tonofilaments and desmosomes were markedly reduced, keratinosomes were increased in number. (b) In the recovery stage, seen after 3 weeks of administration, the horny layer had reappeared, the edematous and vacuolar changes were diminished and the epidermis became slightly acanthotic. Hypergranulosis with numerous spongiform keratohyalin granules was a prominent feature. The number of tonofilaments, desmosomes, and keratinosomes showed a clear tendency to normalization. In conclusion, high systemic doses of aromatic retinoid initially exert a cytotoxic, keratolytic, and mucoplastic effect on the normal guinea pig epidermis. Nevertheless, the affected keratinocytes adapt themselves, despite the further administration of the drug, showing a gradual restoration of these changes and a stimulation of epidermal proliferation, leading to acanthosis.

The effect of long-term ultraviolet irradiation on the connective tissue of the skin was investigated in 25 naked (Ng/-) mice which received a total daily radiant dose of 40 +/- 2 J/cm2 for a period of 8.5 months. The produced alterations were very similar to those found in actinic elastosis of humans, as assessed by histologic and electron-microscopic criteria.

In 64 patients with psoriasis and in 54 persons without any skin disease the amount of zinc was estimated in plasma and in the erythrocytes using atomic absorption spectrophotometry. The findings showed an elevated plasma level and a lower zinc content of blood erythrocytes in psoriasis. Both values were statistically significant. No relation was found between these changes and the percentage skin surface covered by psoriatic lesions. The disturbed distribution of zinc in psoriasis may be due to disturbances if histidine metabolism or to changes of the permeability of the cell membranes associated with this skin disease.

The influence of all-trans retinoic acid, 13-cis retinoid acid and two aromatic retinoids (Ro 10-1670, Ro 11-1430) on the chondrogenic differentiation of mesenchymal cells in vitro was studied electron-microscopically. Organ cultures of limb buds from mouse embryos (Day 11) and high-density cultures of embryonic-mouse mesenchymal cells (Day 12) were used as experimental models. After a 6-day culture in the control medium, the development of hyaline cartilage was observed in both systems. In cultures which were treated with retinoids from Day 1 through Day 3 and then incubated in the control medium for 3 more days, the mesenchymal cells still maintained the morphological features of the blastema stage; cartilage synthesis was reduced (low retinoid concentrations) or completely absent (high retinoid concentrations). These findings indicate that the treatment of embryonic-mouse mesenchymal cells with retinoids induces a persistent and dose-dependent inhibition of chondrogenic differentiation, which in quantitative terms, is variably expressed during treatment with different retinoids. These inhibitory effects of retinoids on chondrogenesis are probably implicated in the pathogenetic mechanisms of their teratogenic action in vivo.