Mediated exodus of L-dopa from human epidermal Langerhans cells.

L-3,4-dihydroxyphenylalanine (L-dopa) is not metabolized within human epidermal Langerhans cells (LC); yet they can take up substantial amounts of this amino acid which subsequently can be released into the extracellular space. We recently reported that human epidermal energy metabolism is predominantly anaerobic and that the influx mechanism is a unidirectional L-dopa/proton counter-transport system and now we describe conditions for the mediated transport of L-dopa out of the LC. It is demonstrated that certain amino acids and one dipeptide can effectively trigger the efflux of L-dopa taken up by the LC.Thus, alpha-methyl-dopa (alpha-m-dopa), D-dopa and the dipeptide, met-ala at the outside of the plasma membrane stimulated the efflux of L-dopa from L-dopa loaded LC. Similar effects were achieved by a variety of other amino acids in the extracellular fluid while some other amino acids were inactive. The time required for 50% D-methionine-induced exodus of L-dopa from L-dopa loaded LC was in the range of 5-7 min and a complete exodus of L-dopa was attained at about 20 min of incubation. This dislocation of L-dopa to the extracellular fluid is interpreted as an expression of trans-stimulation. In the case of alpha-m-dopa, D-dopa and met-ala, which admittedly were not able to penetrate the plasma membrane of LC, the concept of trans-stimulation was given a new purport, since none of them were able to participate in an exchange reaction. Finally, it could be concluded that L-dopa escaped by a route different from the one responsible for L-dopa uptake in LC.Thus, while the influx of L-dopa supports extrusion of protons deriving from anaerobic glycolysis in the LC, L-dopa efflux can provide the cells with useful amino acids in an energy-saving way, altogether a remarkable biological process. From this follows that L-dopa has a biological function of its own, besides being a precursor in the catecholamine and pigment syntheses.

Inhibition of the L-dopa transport system in human epidermal Langerhans cells by omeprazole and its analogues.

L-3,4-dihydroxyphenylalanine (L-dopa) transport into human Langerhans cells (LC) occurs by a saturable mediation. This plasma membrane agency is, due to its characteristics, distinguishable from systems transporting other neutral, cationic and anionic amino acids into other cells and serves to catalyze the flow of L-dopa, only, into LC. The uphill operation of this L-dopa transport system is believed to occur by down-gradient countermigration of H(+). Due to the uniqueness of the L-dopa transport system, the widely used analogue inhibition approach was not applicable. Instead we studied omeprazole and its analogues in our search for suitable inhibitory candidates. Omeprazole and most of its analogues were indeed inhibitory in the concentration range 1-100 micromol/L. Conspicuously, the compounds with strongest polarity were least inhibitory. The inhibitory pattern displayed by omeprazole and the other analogues on L-dopa uptake in LC corresponded to some extent to what has been observed previously for purified H(+),K(+)-ATPase from tubulovesicles of the stomach. No effects of the inhibitors were registered on energy charge and lactate production of epidermal biopsies, nor were any gross alterations of ultrastructure of LC noticed.

Kinetics of the superficial perfusion and temperature in connection with photodynamic therapy of basal cell carcinomas using esterified and non-esterified 5-aminolaevulinic acid.

BACKGROUND: Photodynamic therapy (PDT) is a local treatment modality with increasing indications for various malignant and non malignant diseases. The treatment parameters have not yet been optimized as there is a need for a better understanding of the process. The skin is an important target and serves as a good model for monitoring and evaluating the interaction of light with biological tissue. OBJECTIVES: The tissue perfusion and the temperature of basal cell carcinomas were measured in connection with PDT in order to investigate the biological mechanisms involved. METHODS: An infrared camera was used during the treatment to measure skin temperature and a laser Doppler perfusion imaging device was used to image the superficial perfusion before and after treatment. Six hours after topical application of 5-aminolaevulinic acid (ALA) or methyl esterified ALA (ALA-ME), 38 basal cell carcinomas were treated using light from a diode laser at 633 nm. RESULTS: In the lesions, the perfusion immediately after PDT was similar to that before PDT. One hour after the treatment the perfusion in the lesion was increased 50% compared with before PDT. However, in the skin surrounding the lesions the perfusion was doubled immediately after PDT and was still increasing 1 h after treatment. A temperature increase in the lesions of about 1-3 degrees C was observed for light fluence rates of 100-150 mW cm-2. In all patients treated, a diffuse temperature increase was visible outside the lesions. In some of the patients, the outlines of the blood vessels surrounding the treated lesions became visible in the thermal images. Measurements of temperature on healthy volunteers not administered photosensitizer, but illuminated with light of the same fluence rate, showed a similar increase in temperature in the illuminated spots. However, no temperature increase was observed outside the illuminated area. No statistically significant differences were found between the measurements on patients treated with ALA and ALA-ME. CONCLUSIONS: The increased perfusion in the area surrounding the lesions after PDT, as seen by perfusion and temperature measurements, is the result of an inflammatory reaction to the PDT process. However, directly after PDT the perfusion in the lesions was the same as before irradiation. The combination of these observations suggests the presence of local blood stasis during and immediately after the treatment. The temperature measurements showed that the increased temperature was well below the temperature limit of hyperthermal damage. Furthermore, the measurements indicate that the increase in temperature was primarily a consequence of the heat absorbed in the tissue.

Photodynamic therapy vs. cryosurgery of basal cell carcinomas: results of a phase III clinical trial.

BACKGROUND: A previously reported randomized clinical trial showed treatment of Bowen's disease using photodynamic therapy (PDT) with topically applied delta-aminolaevulinic acid (ALA) to be at least as effective as cryosurgery and to be associated with fewer adverse effects. OBJECTIVES: To compare ALA-PDT and cryotherapy in the treatment of histopathologically verified basal cell carcinomas (BCCs) in a non-blinded, prospective phase III clinical trial. METHODS: One lesion from each of 88 patients was included. The BCCs were divided into superficial and nodular lesions. The follow-up period was restricted to 1 year with close follow-up for the first 3 months. Efficacy was assessed as the recurrence rate 12 months after the first treatment session, verified by histopathology. Tolerability was evaluated as the time of healing, pain and discomfort during and after the treatment, and final cosmetic outcome. RESULTS: Histopathologically verified recurrence rates in the two groups were statistically comparable and were 25% (11 of 44) for ALA-PDT and 15% (six of 39) for cryosurgery. However, clinical recurrence rates were only 5% (two of 44) for PDT and 13% (five of 39) for cryosurgery. Additional treatments, usually one, had to be performed in 30% of the lesions in the PDT group. The healing time was considerably shorter and the cosmetic outcome significantly better with PDT. Pain and discomfort during the treatment session and in the following week were low, and were equivalent with the two treatment modalities. CONCLUSIONS: In terms of efficacy, ALA-PDT is comparable with cryosurgery as a treatment modality for BCCs. Retreatments are more often required with PDT than with cryosurgery. This can easily be performed due to the shorter healing time, less scarring and better cosmetic outcome that follows ALA-PDT.

Blood perfusion studies on basal cell carcinomas in conjunction with photodynamic therapy and cryotherapy employing laser-Doppler perfusion imaging.

Superficial blood perfusion was monitored using laser-Doppler perfusion imaging in connection with a phase III clinical trial comparing photodynamic therapy, utilizing topically applied delta-aminolevulinic acid, with cryotherapy of basal cell carcinomas. A total of 526 images were recorded before and immediately after the treatment and during the follow-up period. Before treatment, the lesions exhibited a blood perfusion 3+/-2 times that in normal tissue. Both treatment modalities induced an increased blood perfusion inside the lesions, which slowly approached normal values in conjunction with successful treatments. The blood perfusion in successfully treated lesions approached normal values 2 months after photodynamic therapy, and about 1 year after cryotherapy. The tissue perfusion in recurrent lesions did not decrease to normal values after the treatment, suggesting that the laser-Doppler perfusion imaging technique can be used to follow the healing process and discover possible persistent tumour growth.

Human herpesvirus 8 (Kaposi's sarcoma-associated herpesvirus) DNA in Kaposi's sarcoma lesions, AIDS Kaposi's sarcoma cell lines, endothelial Kaposi's sarcoma simulators, and the skin of immunosuppressed patients.

We used the polymerase chain reaction on 63 tissue specimens of histologically staged classic Kaposi's sarcoma (KS) from 40 patients, 14 specimens from 14 acquired immune deficiency syndrome (AIDS)-KS cases (all from the same geographic area over a 10-year period), and peripheral blood mononuclear cells from 1 of the non-AIDS KS patients to amplify a specific 210-bp genomic sequence of the newly discovered KS-associated herpesvirus (KSHV). Also tested were 86 benign and malignant endothelial lesions, which potentially simulated each KS histological stage and were further matched by age approximation and by sex with a classical KS specimen. The lesions included hemangioma, lymphangioma, pyogenic granuloma, and angiosarcoma. KSHV was also sought in multiple well characterized vascular endothelial cell lines from AIDS-KS lesions and in 20 mainly cutaneous benign and malignant lesions from 15 immunosuppressed transplant patients. Overall, 92% of KS tissue specimens, representing 88% of classical KS and 100% of AIDS-KS patients, and in addition the sample of peripheral blood mononuclear cell DNA, were positive as visualized on ethidium bromide gels and confirmed by Southern blot hybridization (only 1 case was negative on gell visualization but positive on Southern blot), thus confirming the close association of KSHV with KS of different clinical forms. None of the various other endothelial lesion, skin lesions in immunosuppressed patients, or AIDS-KS endothelial cell lines contained amplifiable KSHV DNA, which indicates that reactivation of KSHV is not present in the skin lesions of immunosuppressed patients and probably is not a ubiquitous agent that secondarily infects proliferative endothelium. The absence of amplifiable virus DNA in the cultured endothelium of KS suggests that the stimulus for angioproliferation originates in another host cell or under conditions not reproduced in culture. The polymerase chain reaction is a specific and sensitive means of verifying KS in the differential diagnosis of angioproliferative lessons.

Major basement membrane components in Kaposi's sarcoma, angiosarcoma and benign vascular neogenesis.

Recent cell biologic studies have emphasized the importance of the basement membrane (BM) and its molecular components in angiogenesis. We immunostained 60 angioproliferative lesions (angiosarcoma, sclerosing hemangioma of skin, pyogenic granuloma, capillary hemangioma, lymphangioma, glomangioma and granulation tissue) and 23 cases of Kaposi's sarcoma (KS) for the major macromolecular components laminin, collagen type IV, fibronectin and heparan sulfate proteoglycan (HSPG). Normal structures served as aggregate controls in each group, and semiquantitative scoring reflected the degree of consistency of staining about blood and lymphatic endothelium and vascular sheath (pericyte/smooth muscle) within and peripheral to each lesion. Benign and reactive vasoproliferations consistently maintained immunoreactivity for each BM component around endothelium and sheath components of blood vessels. Angiosarcoma showed from 20 to more than 60% less consistent immunoreactivity by comparison, although the score variances were greater than for non-malignant lesions. Staining about blood vessel endothelium was both strong and consistent among histologic stages in KS with the exception of HSPG, which was weakly immunoreactive in all stages. Marked selective HSPG loss was characteristic only of KS and normal lymphendothelium, and in the light of evidence for a role for HSPG in the assembly and maintenance of BM, suggests that reduced HSPG may be responsible for the loss of ultrastructural integrity of perivascular BM in both.

Ultrastructural development of Kaposi's sarcoma in relation to the dermal microvasculature.

Ultrastructural subtypes of endothelial cells in Kaposi's sarcoma were compared with lymphatics and the normal dermal microcirculation in different stages of lesional development. In the earliest patch stage, lymphatic channels, recognised by their dissecting growth pattern and a lack of a basal lamina and pericytes, were prominent. Venous endothelium was recognised by virtue of its multilaminated basal lamina and often showed markedly irregular luminal and abluminal cytoplasmic projections. As the histological stage progressed toward spindle cells, venous endothelium showed a tetrad of changes: dissolution of the basal lamina; fragmentation and disappearance of the pericyte sheath, decreased and often rudimentary intercellular junctions and markedly reduced numbers of Weibel-Palade bodies. These were also features of spindle cells, which were rarely seen to emerge from narrow vascular channels of indeterminate type. Spindle cells showed sparse intercellular junctions and minimal basal lamina but no Weibel-Palade bodies. These progressive venous alterations thus resulted in a mixed intermediate subtype of endothelium with the morphological traits resembling lymphatics as well as venous blood vessels. The mixed subtype included endothelial tubes surrounded by a complete basal lamina but lacking pericytes, and much more commonly, tubes with pericytes but a scanty basal lamina. Both forms had remarkably few or no Weibel-Palade bodies. In the spindle cell stage, normal vessels were largely replaced by the mixed subtype and an indeterminate type of frequently disrupted endothelial tube which lacked a basal lamina as well as a pericytic investment. Dissecting lymphatic channels could not be confidently distinguished from the latter vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Inflammatory reactions from organic pigments in red tattoos.

Two different red pigments used for tattooing were found to give rise to inflammatory reactions in the skin. No inorganic component was found in the pigments. NMR and MS analyses elucidated the molecular structures of two different organic compounds. A bright red pigment was found to be an aromatic azo-derivative, and a red-violet pigment was found to be linear quinacridone. A strong exposure to UV-light was reported in most cases prior to the onset of the inflammation.

Increased incidence of Kaposi sarcoma in Sweden before the AIDS epidemic.

Clinical factors of possible importance for the greater than two-fold rise in the incidence of Kaposi sarcoma of the elderly in Sweden before the AIDS epidemic were reviewed in 63 regional patients. 5 patients had lymphoproliferative disease before or at the time of Kaposi sarcoma, and 4 patients had been receiving steroids (including 1 with lymphoma) at diagnosis. 2 of these 9 patients plus 2 additional patients had received blood transfusions 1-9 years before diagnosis. None of 17 patients tested was positive for HIV-1, and none had signs of an unexplained progressive immune defect. Of the evaluable cases, 27% had diabetes mellitus and 7% had had previous myocardial infarction. However, only the frequency of congestive heart failure (47%) was significantly greater than that of an ambulatory control group (P = 0.001) in the age group 75-84 years. Exposure to cytomegalovirus (CMV) was not more common in 15 Kaposi sarcoma patients than in an age and sex matched control group. No single factor could account for increased Kaposi sarcoma among the elderly. If the classical form has an infectious aetiology, the tumour could arise after effective transmission of the agent (as by a transfusion), especially combined with some degree of immune deficiency or perhaps congestive failure late in life.

Glass fibre irritation and protective creams.

5 commercial products were tested pairwise as prophylaxis against itching and irritation from glass fibres: a commercial cream for glass fibre itching, a silicone spray, an emollient cream, a fatty ointment, and a "cream-ointment". The preparations were found to have very limited value in protection against glass fibre irritation. Some workers even experienced exacerbated itching from all the preparations, including the cream marketed for protection against glass fibre irritation. Only 25% of a group of workers with severe glass fibre itching still used an emollient cream after 12 weeks.

Itching from wool fibres in atopic dermatitis.

In 24 girls with atopic dermatitis and a history of irritation to wool, more intense itching was provoked on normal skin on the abdomen by a material with coarse wool fibres (36 microns) than with thinner fibres (20 microns). The probability of the materials causing itching could be predicted by the girls by handling the materials.