Photodynamic therapy with topical photosensitizers in mucosal and semimucosal areas: Review from a dermatologic perspective

Photodynamic Therapy is a procedure based on the interaction between a Photosensitizer, a light source with a specific wavelength and oxygen. The aim of this review is to provide a brief and updated analysis of scientific reports on the use of PDT with topical PS in the management of oncological, infectious, and inflammatory disorders involving mucosal and semimucosal areas, with a specific focus on diseases of dermatologic interest.

ALA-PDT exerts beneficial effects on chronic venous ulcers by inducing changes in inflammatory microenvironment, especially through increased TGF-beta release: A pilot clinical and translational study

A cohort of 19 patients affected by chronic venous ulcers was recruited from our centre. A 4-mm punch biopsy from wound bed was taken before application of ALA 20% gel and repeated one hour after the first PDT irradiation. We observed a significant and progressive reduction of wounds mean volumes right after three ALA-PDT sessions (once per week; 4479.9 +/- 345.5 mm³ vs 34599 +/- 190.3 mm³, p < .01). On immunofluorescence staining from biopsy specimens, we observed a change in all tested stains of post treatment specimens compared to pre-treatment ones. An increase of plasmacytoid dendritic cells (from 699 +/- 22 cells/0.018 mm² to 1369 +/- 27 cells/0.018 mm², p < .0001); MHC-II expression (260.39 +/- 99.7 Red, Green, Blue [RGB 0-255] to 370.2 +/- 162.6 RGB (0-255), p < .01), TNF-alpha positive mast cells expression (49 +/- 0.3 cells/0.018 mm² to 69 +/- 0.4 cells/0.018 mm², p < .001), TGF-beta expression (59.89 +/- 23.2 RGB (0-255)/cell vs 137.39 +/- 56.6 RGB (0-255)/cell, p < .01) and CD4+/CD25+ Treg cells (39 +/- 1 cells/0.018 mm² vs 209 +/- 10 cells/0.018 mm², p < .001) was observed. An increase of TGF-beta was correlated in a statistical significant manner with a reduction of wounds' mean volumes.

Efficacy and safety of S-acyl glutathione 2% cream vs. placebo against UVB-induced erythema: a randomized, double-blinded clinical trial

BACKGROUND

Reactive oxygen species have a major role in the UV-induced short- and long-term damage, thus the exogenous supplementation of antioxidant molecules may allow better skin protection. Despite glutathione has pivotal properties in the complex cytoplasmic antioxidant system, its supplementation is hampered by limited transmembrane absorption. Modification of glutathione pharmacokinetic properties via acetylation with long-chain polyunsaturated fatty acid may improve its passage through phospholipidic membranes.

METHODS

This was a single center randomized double-blinded clinical trial, versus placebo, cross-sectional pairwise at time 0. The participants were 10 healthy volunteers with skin phototypes II or III and age ≥18 years interested in performing minimal erythema dose (MED) evaluation performed by photoallergology unit of Division of Dermatology at P. Palagi Hospital, in Florence. Each volunteer underwent UVB phototesting, treating four different areas with increasing UVB doses in four different conditions. One arm was treated as standard procedure (naïve arm), one applying linolenic-glutathione conjugate (Lin-GSH) cream 2% before irradiation (pre-Lin-GSH arm), one with placebo (placebo arm) and one applying Lin-GSH cream 2% (SoloSale Srl, Florence, Italy) after irradiation (post-Lin-GSH arm). The main endpoint was to evaluate efficacy of Lin-GSH cream 2% before UVB irradiation compared with placebo. A secondary endpoint was the evaluation of the same cream applied after irradiation compared to no treatment. Another secondary objective is the evaluation of safety in both conditions. Mean MED was evaluated at distinct conditions. Safety was evaluated reporting all grade 3-4 adverse events up to 30 days after treatment. All volunteers were treated in all four experimental conditions. The pre-Lin-GSH and placebo arms were applied in a double-blind condition for each volunteer. Neither the volunteer nor the investigator executing MED evaluation knew which arm was given Lin-GSH and which one placebo.

RESULTS

Ten volunteers among 12 recruited for the study were correctly randomized and completed all study evaluations. Recruitment went from April 1st, 2016 to May 1st, 2016, up to adequate population number. Mean MED in pre-Lin-GSH arm was superior to mean MED in placebo arm (135±5.53 mJ/cm2 vs. 105±7.64 mJ/cm2, P=0.0003). No difference was observed among mean MED in post-Lin-GSH and naïve arms. No grade 3-4 adverse events were reported.

CONCLUSIONS

Lin-GSH 2% cream seems a safe and effective in producing a significant increase in MED compared with placebo thanks to its antioxidant properties.

Early activation of fibroblasts during PDT treatment in leg ulcers

BACKGROUND

This pilot study was aimed to assess the variations of some microscopical parameters in skin ulcers, caused by chronic venous insufficiency of the lower extremities (chronic leg ulcers), in 15 patients refractory to previous conventional treatments during photodynamic therapy (PDT).

METHODS

Samples of control, wounded and PDT treated skin were taken and analyzed by immunohistochemistry.

RESULTS

The cellular infiltrate, as well as the thickness of epidermis, vascularization, mast cell and fibroblast numbers, were increased in chronic wounds as compared to healthy skin. After completion of PDT, fibroblasts appeared further increased in number. Mast cells, closely clustered with fibroblasts, also showed an increase in their numbers, degranulation index and expression of basic fibroblast growth factor.

CONCLUSIONS

The present findings support a primary role of fibroblasts in the wound healing process upon PDT treatment, given their early and intense reaction to injury. Mast cells seem to play an accessory yet important role, on the basis of their number and degranulation index variations and expression of basic FGF. In addition, the clustering of mast cells with fibroblasts around blood vessels suggest that these cells may stimulate angiogenesis and, in parallel, fibroblasts to secrete extracellular matrix during PDT therapy.

Photodynamic therapy for chronic venous ulcers

Some laboratory findings and a few case reports support the treatment of chronic venous ulcers with photodynamic therapy. We treated 19 patients with refractory chronic venous ulcers using photodynamic therapy. The ulcers healed in 15 cases (78.9%) after an average of 6.8 photodynamic therapy sessions (range 6.0-8.0). In the remaining 4 cases, the ulcers showed marked improvement after 10 photodynamic therapy sessions. Photodynamic therapy seems to represent a good alternative therapeutic choice for refractory chronic venous ulcers.

Squamous Cell Carcinoma of the Eyelid Treated with Photodynamic Therapy

The ocular tissues can be the site of a number of malignant tumors in adults. Approximately 5% to 10% of all skin tumors occur in the eyelid. Incidence studies indicate that basal cell carcinoma is the most frequent malignant eyelid tumor (90%) followed by squamous cell carcinoma (9%). A 55-year-old man presented a squamous cell carcinoma (SCC) of 8 mm diameter, localized in the middle third of the lower eyelid, 3 mm under the eyelid margin on the eyelids. The histopathologic examination of a biopsy specimen showed the typical features of squamous cell carcinoma. Photodynamic therapy (PDT) with topical 5-aminolevulic acid (ALA) after Frost suture was employed. Very good results were obtained with rapid healing, without invasiveness, and without anesthesia. There was no evidence of scar formation and no signs of recurrence at 6 months follow-up. Many therapeutic methods have been suggested for squamous cell carcinoma of the eyelid. We consider photodynamic treatment of eyelid skin malignancies to be of great interest and it may represent an interesting future perspective for their management especially when surgical intervention cannot be tolerated by the patient.

Depigmentation patterns of nonsegmental vitiligo: a prospective study of macromorphologic changes in lesions

BACKGROUND

Efforts have been recently made to investigate simple, objective, accurate, and reproducible methods of clinical/noninvasive assessment of nonsegmental vitiligo. However, studies have mostly considered quantitative or semiquantitative parameters, almost neglecting the purely qualitative appearance of vitiligo lesions at a given moment and over time.

OBJECTIVE

The objective of this study was to investigate the dynamics of macromorphologic alterations taking place within vitiligo patches.

STUDY DESIGN

This was a prospective study of a vitiligo cohort.

PATIENT POPULATION

Consecutive patients affected by nonsegmental vitiligo.

METHODS

Enrolled patients affected by nonsegmental vitiligo underwent a dermatology visit once monthly for 12 months. Vitiligo lesions were photographed at each visit under both room light and Wood's light, and analyzed via a morphometric, digitalized software capable of detecting quantitative changes of white areas. Pictures depicting changing patches were evaluated in order to assess clinical morphology.

RESULTS

Ninety patients were included for the final analysis and 360 lesions were evaluated, 102 of which (28.9 %) showed changes of white areas. Subjective evaluation highlighted two distinct depigmentation patterns, which were present either alone or in combination: (1) a sharply defined band of intermediate color between the depigmented center and the surrounding normal skin, which was defined as 'marginal hypopigmentation;' and (2) pinpoint hypopigmented/depigmented macules centered by a follicle, which we named 'perifollicular depigmentation.' On the other hand, only one repigmentation pattern was detected, the already known 'perifollicular repigmentation.'

CONCLUSION

The depigmentation process in vitiligo seems to follow only two specific patterns. This preliminary study represents, in our opinion, a valuable background for future research aiming to investigate the dynamics of vitiligo pathogenesis or assess depigmentation/repigmentation patterns for monitoring treatment response.

Treatment of anogenital condylomata acuminata with topical photodynamic therapy: report of 14 cases and review

Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) is an emerging technique for the treatment of genital human papillomavirus (HPV)-induced benign and premalignant lesions. We report herein a case series of anogenital CA successfully treated with ALA-PDT and review the literature available to date on this topic. Thirteen out of 14 cases of anogenital condylomata acuminata were successfully treated with topical PDT. We conclude that PDT can be considered a highly effective and safe treatment option for anogenital condylomata acuminata. Also, considering the available literature, the best results are likely to be achieved with a 16-20% gel formulation of 5-ALA and a red light dose of 100-150J/cm(2).

Vascular endothelial growth factor receptor-2 and low affinity VEGF binding sites on human glomerular endothelial cells: Biological effects and advanced glycosilation end products modulation

Vascular Endothelial Growth Factor (VEGF), binding to its receptor in endothelial cells, seems to modulate the increased blood flow in the early phase of diabetic renal disease. The aim of the study was to evaluate, in a diabetic milieu, the expression, biological function and modulation of VEGF binding sites in human glomerular endothelial cells (GENC). We demonstrated the presence of VEGF binding sites with high (VEGFR-2) and low (heparan sulfate proteoglycans, HSPG) affinity. VEGF165 and VEGF121 working through VEGFR-2 stimulated nitric oxide (NO) production at low doses (0.1-1 nM), whereas only VEGF165 at high doses (10-100 nM) increased thymidine incorporation. 1 nM VEGF165 and VEGF121 induced in GENC a significant peak of inducible NO synthase (iNOS) production and, at a lower level, of endothelial NOS (eNOS). The copresence of VEGF165 with aminoguanidine (iNOS inhibitor) determined an increase of eNOS and a significant increase in thymidine incorporation. Advanced glycation end products (AGEs) working through specific receptors (RAGE) up-regulated the expression of VEGFR-2, decreased the expression of HSPG sites and reduced GENC growth. These results identify in GENC VEGFR-2 as a mediator of iNOS and eNOS release under control of VEGF, whereas HSPG binding sites seem to mediate the weak growth effect. The presence of AGEs, up-regulating the VEGFR-2 and decreasing HSPG sites might participate to the block of glomerular angiogenesis addressing the VEGF effects on glomerular permeability.

Topical photodynamic therapy for primary cutaneous B-cell lymphoma: a pilot study

Photodynamic therapy (PDT) is a treatment based on the accumulation of a photosensitizer in the target cells and their selective destruction by irradiation with visible light. In the past 10 years, several patients with cutaneous T cell lymphoma have been successfully treated. The use of PDT in cutaneous B cell lymphoma has not been reported to date. We report the successful PDT treatment of 3 patients with early primary cutaneous B cell lymphoma.

New proposal for the treatment of nodular basal cell carcinoma with intralesional 5-aminolevulinic acid

Photodynamic therapy (PDT) is a treatment modality using a photosensitizer, light and oxygen to cause photochemically-induced selective cell death. Topical PDT is most suitable for thin lesions such as superficial basal cell carcinoma and actinic keratoses in dermatology. Results with PDT as treatment of thicker lesions such as nodular basal cell carcinoma appear to have a limited role because the photosensitizer or the light cannot penetrate deeply enough into the thicker tumor volume. In this preliminary study we use intralesional administration of 5-aminolevulinic acid to enhance the efficacy of the photosensitivity of nodular basal cell carcinomas, thus improving clinical cure.

Possible histopathologic correlates of dermoscopic features in pigmented melanocytic lesions identified by means of optical coherence tomography

Optical coherence tomography (OCT) is a novel non-invasive imaging technique for in vivo histologic characterization of tissues. Besides pure morphology, additional functional parameters of the tissue investigated can be evaluated at the same time, such as the refractive index and the scattering coefficient. The purpose of our study is to correlate in vivo the dermoscopic structures that first appear in the melanocytic pigmented lesion (pigment network and brown globules) using this new method, with the histopathologic correlates, in order to improve their characterization and achieve easier recognition and inter-observer reproducibility. We concentrated in particular on the pigment network and the brown globules, as these are dermoscopic parameters of great diagnostic importance in melanocytic lesions. Moreover, as these parameters are the histopathologic equivalents of structures located at the level of the dermo-epidermal junction, they enable a correct evaluation to be made using OCT, that at present has only a few millimetres penetration power. The results of our trial, performed using the histopathological preparation as an evaluation gold standard, show that in selected cases OCT allows an in vivo correlation to be made between surface dermoscopic parameters and histopathologic correlates, in particular the pigment network and brown globules. The resolution is not high enough to reveal the morphology of the single cells, but it is possible to evaluate the architecture of a lesion.

Monochromatic excimer light (308 nm) in patch-stage IA mycosis fungoides

Recently, numerous studies have been reported concerning the treatment of early-stage mycosis fungoides (MF) with narrowband (311-nm) UVB, claiming a beneficial response. We have used for the first time a 308-nm monochromatic excimer light, a new kind of xenon-chloride lamp, in the treatment of patch stage IA MF. We treated 7 patch lesions in 4 patients with unequivocal clinicopathologic diagnosis of MF. All lesions achieved clinical and histologic complete remission. The number of weekly sessions varied from 4 to 11 (mean 6.5; median 5.5). The total UVB 308-nm irradiation dose ranged from 5 to 9.3 J/cm(2) (mean 7.1 J/cm(2); median 7 J/cm(2)). All lesions remained in stable complete remission after a follow-up of 3 to 28 months. No remarkable side effects were reported. Our preliminary results suggest that monochromatic excimer light phototherapy is a possibly very useful treatment modality in patch stage IA MF.

BCA-1, A B-cell chemoattractant signal, is constantly expressed in cutaneous lymphoproliferative B-cell disorders

We analysed the immunophenotypic and molecular expression of BCA-1 (B-cell-specific chemokine) and CXCR5 (BCA-1 receptor) in normal skin and different cutaneous lymphoproliferative disorders (cutaneous T-cell lymphoma (CTCL); cutaneous B-cell lymphoma (CBCL); cutaneous B-cell pseudolymphoma (PCBCL)), with the aim of investigating their possible involvement in the pathogenesis of cutaneous B-cell disorders. BCA-1 and CXCR5 were constantly expressed in CBCL and PCBCL, but not in normal skin and CTCL. BCA-1 and CXCR5 were constantly coexpressed by CD22+ B-cells, while CD35+ follicular dendritic cells coexpressed BCA-1 in PCBCL cells only. In low grade CBCL, as compared with high grade CBCL, the intensity of CXCR5 expression on neoplastic CD22+ cells was lower than that of BCA-1. The image analysis of reverse transcriptase-polymerase chain reaction (RT-PCR) products showed a significant quantitative difference between PCBCL/low grade CBCL and high grade CBCL. The above findings, although only observed in a small series of patients, are in keeping with findings in MALT gastric and gastric MALT lymphomas, adding further evidence of the close similarities between CBCL and MALT lymphomas.

Monochromatic excimer light (308 nm): an immunohistochemical study of cutaneous T cells and apoptosis-related molecules in psoriasis

BACKGROUND

Various types of UVB radiation source (290-320 nm) are used in treating psoriasis and their therapeutic mechanism has been attributed to immunosuppressive properties. Recently, a new UVB source generated by a 308-nm excimer laser has been introduced for the treatment of psoriasis.

OBJECTIVE

In this study we investigated the immunohistochemical evaluation of T cells and the expression of various apoptosis-related molecules in the psoriatic hyperproliferative skin before and after treatment with 308-nm monochromatic excimer light (MEL).

METHODS

Ten patients (three women and seven men), ranging in age from 29 to 79 years, affected by plaque-type psoriasis vulgaris, were treated with MEL. Biopsies from psoriatic lesions of MEL-treated sites were taken before, 24 h and/or 48 h after the first irradiation and analysed by the immunophosphatase alkaline technique (APAAP).

RESULTS

MEL treatment was found to cause a significant decrease in the rate of proliferation of keratinocytes and a relevant depletion of T cells in all psoriatic lesions, 48 h after the first irradiation: 308 nm light eliminated T cells from the psoriatic epidermis and also from the dermis, highlighting the ability of this UVB source to penetrate the skin compared with normal UVB and establish direct cytotoxic action on T cells infiltrating skin lesions. Rapid clearing of psoriatic lesions involves potential molecular targets of UVB in T cells including p53, which is upregulated after direct irradiation with 308-nm UVB. Moreover, Bcl-2 expression in healing psoriasis epidermis after MEL treatment is significantly decreased compared with untreated skin and the TUNEL (TdT-mediated dUTP-biotin nick end labelling) technique revealed the presence of relevant apoptotic keratinocytes in the irradiated epidermis.

CONCLUSIONS

These results indicate that psoriatic skin after monochromatic excimer light therapy is associated with significant T-cell depletion and alterations of apoptosis-related molecules accompanied by a decreased proliferation index and clinical remission.

AT1 and AT2 receptors in human glomerular endothelial cells at different passages

In human adult kidney angiotensin II (AngII) effects are mediated by the AT1 receptor, while the functions of AT2 receptors are mostly unknown. Since AngII regulates endothelial cell growth by AT1 and AT2 receptors, we analysed their functional aspects at different passages in human glomerular endothelial cells (GENC). Semiquantitative reverse transcription-polymerase chain reaction revealed the presence of AT1 and AT2 receptors between 2p and 15p cell passages with different levels of expression. In fact, binding studies of different families of displacement curves using AngII, DUP753 (AT1 antagonist), and PD123177 (AT2 antagonist) showed the presence of AT1a and AT2 receptors at 4p-9p while in GENC 2p only the presence of AT2. In terms of mitogenic activity, AngII was unable to stimulate GENC 2p growth. On the contrary, in GENC 4p-9p and 15p a significant thymidine incorporation was observed. This stimulatory effect seemed to be induced also by the concomitant release of PDGF-BB AT1a mediated. In conclusion, AT1a and AT2 receptors are represented in GENC with a different ratio depending upon the cell passage. AngII regulates the mitogenic effect through AT1a receptors (in later cell passages 4p-15p) involving the release of PDGF-BB, while AT2 (in early cell passage 2p) showed a predominant negative growth control.

CO2 laser therapy in a case of steatocystoma multiplex with prominent nodules on the face and neck

BACKGROUND

Steatocystoma multiplex is an uncommon disorder which usually begins in adolescence or early adult life. The condition can be hereditary, as an autosomal dominant trait, or nonhereditary, as in this case.

METHODS

A 40-year-old woman presented with a history of asymptomatic nodules that began around puberty on the face. There was no family history of similar lesions. Clinical examination revealed multiple nodules distributed on the face and neck. The histopathologic examination of a biopsy specimen showed the typical features of steatocystoma multiplex. CO2 laser therapy without anesthesia was employed, and the contents were evacuated by squeezing the cysts with a pair of forceps.

RESULTS

Very good results were obtained with rapid healing, minimal invasiveness, and without anesthesia. There was no evidence of scar formation and no signs of recurrence at 2-year follow-up.

CONCLUSIONS

Different treatments have been reported for steatocystoma multiplex. We consider CO2 laser therapy to be an ideal technique for the treatment of steatocystoma multiplex, especially when the lesions are localized in aesthetically important areas.

Immunophenotypical markers, ultrastructure and chemosensitivity profile of metastatic melanoma cells

The survival of patients affected by cutaneous melanoma has improved dramatically in the last 10 years, because of earlier diagnosis. Despite this, the therapeutic results obtained in metastatic melanoma (MM) are very disappointing due to its poor responsiveness to cytotoxic agents. In this type of solid tumor, tumor chemosensitivity assays have been suggested to be an important tool to predict clinical responsiveness to therapy. Metastatic melanoma cells (MMCs) were obtained from subcutaneous melanoma metastases of five patients and cultured for several consecutive passages. An immunofluorescence and an electron microscopic study were performed in order to establish the ultrastructural and physiopathological features of MMCs. A sulphorodamine-B test was used to measure in vitro sensitivity of MMCs to temozolomide, cisplatin, vindesine, taxol and interpheron alpha-2a. Following a 72 h exposure, maximum activity was obtained with vindesine (median inhibitory concentration, IC(50), 0.23 nM) and taxol (median IC(50) 0.31 nM). Cisplatin median IC(50) values were higher (4.6 microM) than taxol and vindesine, but still in the range of clinically achievable plasma concentrations. Temozolomide inhibited cell proliferation only at very high concentrations (median IC(50) 228 microM). No significant cell growth inhibitory effects (<or=25%) were observed with interferon alpha-2a concentrations up to 8000 IU/ml. MMCs expressed progression markers typical of cutaneous metastatic melanoma and showed poor sensitivity in vitro to most anticancer drugs tested, including temozolomide.

Giant exophytic basal cell carcinoma treated with radiotherapy

Basal cell carcinomas may attain giant proportions due primarily to recurrence or because the tumour is neglected. We report the case of a 66-year-old man who presented with a bleeding, polypoid, cutaneous tumour located on the left shoulder region of 13 years duration. The man had not received any previous treatment. The lesion was biopsied and histopathologically diagnosed as a solid type basal cell carcinoma with focal areas of squamous differentiation and keratinization. The man refused complete surgical removal and therefore was treated with roentgentherapy, with satisfactory results and no complications in the irradiated area. No recurrences had manifested after 1 year follow-up.

Raynaud's phenomenon (primary or secondary to systemic sclerosis). The usefulness of laser-Doppler flowmetry in the diagnosis

BACKGROUND

Raynaud's phenomenon (RP) consists of painful vascular spasms of the extremities stressed by cold exposure. It is often a symptom, in many cases the onset, of systemic sclerosis (SSc). The aim of this study was to evaluate the role that laser-Doppler flowmetry (LDF) could have in the differential diagnosis of these disorders and to characterize the functional behaviour of the microvessels in RP.

METHODS

In this study we examined 52 patients (five males and 47 females, aged 17-57) affected by primary RP, 21 patients (three males and 18 females, aged 31-63) affected by RP secondary to SSc as defined by Wouda in 1987 and 20 healthy subjects (three males and 17 females, aged 26-58) by means of LDF with an appropriate cold-test (11 degrees C for 2 min).

RESULTS

We show that the cold test applied at hand level can distinguish RP patients from healthy subjects. Data show that basal blood flow of patients affected by SSc is diminished in its medium value and presents a typical tracing without vasomotion in comparison to healthy subjects and also to patients affected by primary RP. On the basis of our data among the primary RP patients we can also distinguish a group that show basal blood flow tracing very similar to that of sclerodermic patients. These subjects should be carefully followed-up.

CONCLUSIONS

In conclusion, it could be stimulating for the future to introduce LDF as a complementary method for the diagnosis of RP and possibly for early discrimination between the primary disease and that secondary to SSc.

IGFBPs modulate IGF-I- and high glucose-controlled growth of human retinal endothelial cells

Insulin-like growth factor binding proteins (IGFBPs) are important local factors in the development of proliferative diabetic retinopathy. We investigated the effects of IGF-I and increased glucose concentrations on the release of IGFBPs and the growth of human retinal endothelial cells (HRECs). HRECs secrete IGFBPs-2 to -5. IGF-I stimulated thymidine incorporation and modified the pattern of IGFBPs, decreasing the inhibitory IGFBP-4 through down-regulation of its mRNA, and increasing IGFBP-5 which, per se, was able to modulate HREC growth, exerting post-transcriptional control. Studies using an antibody (alpha IR3) against the IGF-I receptor, and compounds with low affinity for IGFBPs, such as insulin and des(1-3)IGF-I, showed that an interaction between IGF-I and IGFBP-5 was necessary to detach this IGFBP from its binding sites. The dose of IGF-I that significantly decreased the IGFBP-4/IGFBP-5 ratio was the same that stimulated HREC growth. Chronic exposure to high concentrations of glucose was able to reduce HREC mitogenesis, interacting with the IGF system through a decrease in the stimulatory IGFBPs-2, -3 and -5, leaving the concentration of the inhibitory IGFBP-4 constant. These results extend our previous observations in endothelial cells and suggest that the IGFBP-4/IGFBP-5 ratio regulates IGF-I-induced growth of HRECs, whereas a general decrease in IGFBPs (except for IGFBP-4) was the anti-proliferative effect of chronic exposure to high glucose concentrations.

Topical 5-aminolevulinic acid and photodynamic therapy in dermatology: a minireview

Photodynamic therapy (PDT) is a treatment modality using a photosensitizer, light and oxygen to cause photochemically induced selective cell death. When exposed to light with the proper wavelength, the topically applied photosensitizer or photosensitizer precursor can activate a biomolecule through electron transfer to yield free radicals or produce singlet oxygen from energy transferred from the excited sensitizer to molecular oxygen. The tissue damage is the result of the activation of reactive singlet oxygen or free radical production. Photodynamic therapy with topical application of 5-aminolevulinic acid (ALA) is a new technique and although it remains largely experimental, it has potential application for treatment of malignant skin tumors, various precancerous and selected benign skin diseases. This technique yields not only a high percentage of good therapeutic results but also excellent cosmetic outcome. This paper reviews the recently published data on clinical ALA-based PDT in dermatology.

Non-invasive analysis of melanoma thickness by means of dermoscopy: a retrospective study

Epiluminescence microscopy (ELM), or dermatoscopy, is a non-invasive technique for the diagnosis of cutaneous melanoma that may play a role in the non-invasive, preoperative assessment of melanoma thickness. This study investigated the correlation between the frequency of appearance of some standard ELM criteria and the histological thickness of melanomas. In addition, the possible role of the total dermoscopic score (TDS) according to ABCD rule of dermoscopy as a predictor of melanoma thickness was analysed. The dermoscopic images of 84 cutaneous melanomas were retrospectively investigated to evaluate the presence of 10 standard ELM criteria, and for each lesion the TDS was established (with observers blinded as to the tumour thickness). A statistically significant association was found between the presence of an irregular pigment network and melanomas with a Breslow index equal to or lower than 0.75 mm (positive predictive value of 68%); in contrast, radial streaming, atypical vascular pattern and grey-blue areas were associated with melanomas > 0.75 mm (positive predictive values of 77%, 65% and 70%, respectively). Of the melanomas thinner than 0.76 mm, 82% showed a TDS lower than 6.80 (optimized cut-off point), while 79% of melanomas thicker than 0.75 mm had a TDS higher than 6.80 (chi2 = 30.815, P < 0.001); the positive predictive value of a TDS > 6.80 in the detection of lesions thicker than 0.75 mm was 79%. In conclusion, a statistically significant correlation does exist between some dermoscopic features and melanoma thickness. Both the mostly used dermoscopic methods (standard ELM pattern analysis and the ABCD rule of dermatoscopy) may provide useful information in the non-invasive assessment of melanoma thickness. However, their diagnostic performance is far from 100%; further studies are needed to investigate whether the combination of dermoscopy with other non-invasive approaches (e.g. sonometry) may result in an overall improvement in the diagnostic performance.

CD30-CD30 ligand interaction in primary cutaneous CD30(+) T-cell lymphomas: A clue to the pathophysiology of clinical regression

Primary CD30(+) cutaneous T-cell lymphomas (CTCLs) represent a spectrum of non-Hodgkin's lymphomas (NHLs) that have been well defined at the clinical, histologic, and immunologic level. This group, which includes 2 main entities (large cell lymphoma and lymphomatoid papulosis [LyP]) and borderline cases, is characterized by the expression of CD30 antigen by neoplastic large cells at presentation, possible spontaneous regression of the skin lesions, and generally favorable clinical course. Although the functional relevance of CD30 and its natural ligand (CD30L) expression in most cases of NHL is presently undefined, previous studies indicate that CD30L is likely to mediate reduction of proliferation in CD30(+) anaplastic large-cell NHL. No information is currently available concerning the expression of CD30L in primary CD30(+) CTCLs. In this study, we investigated the immunophenotypic and genotypic expression of CD30 and CD30L in different developmental phases of skin lesions (growing v spontaneously regressing). By immunohistochemistry, CD30L expression was detected in regressing lesions only; by molecular analysis, the expression of CD30L was clearly higher in regressing lesions than in growing ones. CD30L, while expressed by some small lymphocytes, was most often coexpressed by CD30(+) neoplastic large cells, as demonstrated by 2-color immunofluorescence and by immunohistochemistry on paraffin sections. Taken together, these data suggest that CD30-CD30L interaction may play a role in the pathobiology of primary cutaneous CD30(+) lymphoproliferative disorders. In particular, CD30L (over)expression might have a major role in the mechanism of self-regression of skin lesions, the most distinctive clinical feature of this cutaneous lymphoma subtype.

Human glomerular endothelial cells IGFBPs are regulated by IGF-I and TGF-beta1

The release of insulin-like growth factor binding proteins (IGFBPs) and their regulation in human glomerular endothelial cells (GENC) was characterised. GENC produce IGFBP-4, IGFBP-2 and IGFBP-3 and express mRNA for IGFBP-2 to IGFBP-5. Due to the fact that IGF-I and TGF-beta1 modulate glomerular hypertrophy, their action on IGFBP release and GENC growth was studied. IGF-I increased IGFBP-3, IGFBP-2 and decreased IGFBP-4, while TGF-beta1 decreased IGFBP-3 and apparently increased IGFBP-4. All of the IGFBPs, except the TGF-beta1-regulated IGFBP-4, were modulated at mRNA level. IGF-I stimulated GENC proliferation, while TGF-beta1 inhibited their growth. It was demonstrated that an IGFBP-3 antibody reduced GENC proliferation. However, rhIGFBP-3 alone had no effect on GENC, but after 48 h pre-incubation the IGF-I stimulated GENC growth was increased, suggesting that IGFBP-3 could modulate the IGF-I induced GENC proliferation. It was concluded that the stimulatory IGFBP-3 and the inhibitory IGFBP-4 could regulate GENC growth, although the IGFBP-3 seems to have a predominant effect in this control.

The oligosaccharidic component of the glycoconjugates in lichen planus, granuloma annulare, seborrheic keratosis and plamoplantar keratoderma: lectin histochemical study

It is well known that cell surface glycoconjugates play an important role in cell proliferation, adhesion and differentiation. The aim of this investigation was to define the changes of the glycoconjugate saccharidic moieties in the epidermis and derma of patients affected by several skin pathologies such as seborrheic keratosis, lichen planus, granuloma annulare and palmoplantaris keratoderma. Bioptical specimens from skin lesions as well as from normal skin were fixed in Carnoy's fluid and routinely processed. The sections were treated with HRP-lectins (PNA, DBA, SBA, WGA, ConA, LTA and UEAI). Cytochemical controls were performed for specificity of lectin-sugar reaction. Some sections were pre-treated with neuraminidase prior to staining with HRP lectins. In comparison with normal human skin, epidermal lectin binding pattern in the considered diseases showed considerable qualitative and quantitative variations. In general, in all the considered pathologies, a lack and/or a decrease in lectin binding at the epidermal layers was observed; among the various diseases, differences in cellular localisation of the sugar residues were also noted. In such respect, an exception was represented by seborrheic keratosis, where the cells of the basal layer showed PNA reactivity, which was absent in the basal layer of the normal skin. Although seborrheic keratosis and lichen planus have been studied by others authors, our findings are not in total accordance concerning lectin binding; this is probably due to the different fixatives employed. Our findings seem to reveal significant changes in keratinocyte glycoconjugate oligosaccharides in the previously mentioned diseases, providing clues to their pathogenesis.

Primary tuberculosis of the penis

We present a case of primary tuberculosis of the inner lining of the prepuce in a 63-year-old man. The condition resembled carcinoma. The diagnosis was based on histopathology and on M. tuberculosis culture. Successful treatment was by a combined medical and surgical approach. The rarity of the case is emphasized.

Characterization of [3H]substance P binding sites in human skin

Radioligand binding experiments were performed with crude homogenates from normal human skin in order to investigate substance P receptor density. Binding of [3H]substance P ([3H]SP) reached equilibrium after 20 min and was saturable analysis of saturation curves gave a significantly better fit using two-site binding compared to the single-site model. Competition studies employing some selective agonists for NK1, NK2 and NK3 receptors have demonstrated that only the NK1 selective agonist, [Sar9, Met(O2)11]-SP, was a competitor for [3H]SP binding. In addition, the non-hydrolyzable guanosine 5'-0-(3-thiotriphosphate) altered the dissociation of SP from NK1 receptors by increasing the number of low-affinity sites. These data show that in the skin [3H]SP binds to a single population of substance P high-affinity sites, which represent NK1-type receptors.

The role of histamine in platelet aggregation by physiological and immunological stimuli

BACKGROUND

Platelets participate in allergic and inflammatory processes beside their role in haemostasis and thrombosis. This paper reports the level, the uptake, the metabolism and the release of histamine in human platelets. The effects of exogenous histamine, as well as the receptor and signal transduction of these effects, are also described.

METHODS

Purified suspensions of platelets, prepared from healthy volunteers and from atopic patients, were exposed in vitro to physiological and immunological stimuli. Platelet aggregation was measured by the increase in light transmission; histamine content and release, as well as cytosolic free Ca2+ concentration, were measured fluorimetrically. Platelet histamine forming capacity, and the uptake of exogenous histamine, were measured with a radioisotopic method.

RESULTS

Human platelets contain 72.5 +/- 9.6pmoles of histamine x 10(9) platelets, and their capacity to form histamine is 18.7 +/- 3.5pmoles h(-1)g(-1) protein, which is reduced by alpha-fluoromethylhistidine (10(-5) M) a selective inhibitor of the specific histidine decarboxylase. Human platelets take up the preformed amine by a calcium and energy-dependent process, and the uptake of histamine is reduced by mepyramine, an H1-receptor antagonist, and N,N-diethyl-2-[4-(phenylmethyl) phenoxyl] ethanamine (10(-6) M), a blocker of intracellular histamine receptors. Histamine is also metabolized by human platelets. The exposure of platelets to thrombin (10-60 mUml(-1)) produced a progressive aggregation, associated with histamine release. The same is observed in platelets isolated from atopic patients exposed to anti-IgE antibodies. Exogenous histamine dose-dependently potentiates the aggregation induced by physiological and immunological stimuli. In resting platelets cytosolic calcium level (207 +/- 4.2 nM/10(8) platelets) is increased by thrombin as well as by anti-IgE; this effect is potentiated by 10(-5) M histamine.

CONCLUSIONS

The synergistic effect between histamine and other monoamines on platelet aggregation may explain some aspects of allergic vasculitis in which platelet aggregation is present.

Possible involvement of neuropeptidergic sensory nerves in alopecia areata

Alopecia areata (AA) is a dermatosis involving the sudden occurrence of bald patches on the scalp. Although the aetiology is unknown, experimental data indicate that cutaneous microcirculation plays an important role. The skin is richly innervated by neuropeptidergic sensory nerves that help regulate microvascular circulation. This study shows a reduction of cutaneous levels of substance P and calcitonin gene-related peptide (CGRP) but not of vasoactive intestinal polypeptide in scalp biopsies from patients with AA. Laser-Doppler flowmetry was used to study microcirculation of the scalp. Results indicate that patients with AA have lower basal blood flow and greater vasodilatation following intradermal CGRP injection than control subjects. A vascular hyper-reactivity to vasodilatatory substances such as neuropeptides, probably because of the lack of these substances, is hypothesized.

The effects of repeated dermal application of capsaicin to the human skin on pain and vasodilatation induced by intradermal injection of acid and hypertonic solutions

1. The effect of repeated capsaicin application on the skin of the volar surface of the forearm on the pain sensation and on the increase in blood flow induced by intradermal injection of low pH media or hypertonic solutions was investigated in 13 healthy volunteers. 2. Low pH media (4, and 2.5) were obtained by adding HCl to 0.9% saline. Hypertonic solutions (300 and 600 mM) were obtained by adding NaCl to pH 7.4, 0.9% saline. Capsaicin (1% in 50% ethanol) was painted on the volar skin of one forearm, chosen at random, for 7 days. The contralateral forearm was treated with the capsaicin vehicle. Pain was assessed by a visual analogue scale and skin blood flow by a laser doppler flowmeter. 3. Pain sensation and increase in blood flow (both peak and area under the curve) induced by low pH media were markedly reduced in the capsaicin pretreated side. Capsaicin pretreatment also reduced the increase in blood flow, but did not affect the pain response induced by hypertonic saline solutions. 4. Repeated application of capsaicin to the human skin inhibits both the sensory (pain) and 'efferent' (vasodilatation) responses induced by low pH media, whereas it reduces the vasodilatation, but not the pain caused by hypertonic media. 5. Repeated application of capsaicin to the human skin, a therapy used in various diseases, discriminates between sensory, but not 'efferent' responses induced by different stimuli.

Substance P provokes cutaneous erythema and edema through a histamine-independent pathway

Substance P is a neuropeptide (contained in/and released from the A delta and C nerve fibers of the skin), which provokes erythema, edema, and pruritus after intradermal injection. Local pretreatment with capsaicin produces decreased substance P-dependent erythema, with edema similar to that observed before pretreatment with capsaicin. We injected histamine and in a parallel experiment, substance P in five volunteers before and after local treatment with capsaicin, with 48/80, after 5 days of hydroxyzine. The injection of SP provoked erythema centered by a wheal. After treatment with 48/80, SP provoked increased erythema and a wheal. After hydroxyzine treatment, the injection of histamine produced no erythema or edema in four of the five subjects, while SP provoked erythema in all five subjects and edema similar to that observed before treatment with hydroxyzine. These data support the hypothesis that substance P provokes erythema and edema both with histamine-dependent and histamine-independent pathways.

[Erythrodermic sarcoidosis]

Cutaneous involvement is relatively frequent in patients with sarcoidosis. The histologic evidence of typical non-caseating granulomas differentiates specific from non-specific skin lesions. Among specific cutaneous lesions of sarcoidosis, erythroderma is exceedingly rare. We report here a case of erythrodermic sarcoidosis. The differential diagnosis and the possible correlation with cutaneous T-cell lymphomas are discussed.