Optical superfluid phase transitions and trapping of polariton condensates.

Semiconductor microcavities are used to support freely flowing polariton quantum liquids allowing the direct observation and optical manipulation of macroscopic quantum states. Incoherent optical excitation at a point produces radially expanding condensate clouds within the planar geometry. By using arbitrary configurations of multiple pump spots, we discover a geometrically controlled phase transition, switching from the coherent phase-locking of multiple condensates to the formation of a single trapped condensate. The condensation threshold becomes strongly dependent on the programmed superfluid geometry and sensitive to cooperative interactions between condensates. We directly image persistently circulating superfluid and show how flows of light-matter quasiparticles are dominated by the quantum pressure in such configurable laser-written potential landscapes.

Detection of nodal micrometastases using immunohistochemistry and PCR in melanoma of the arm and trunk.

Sentinel node (SN) mapping and biopsy seems at present the best way to assess the nodal status in cutaneous melanoma without removing the lymphatic chain. The procedure is minimally invasive, safe and low cost, and allows selection of patients who can benefit from elective node dissection. From March 1997 up to July 1999 we examined 112 SNs excised after lymphatic mapping from 95 patients (48 males and 47 females) with stage I cutaneous melanoma affecting the trunk or limbs. Of these, 88 SNs from 74 patients were submitted to polymerase chain reaction (PCR) in order to detect tyrosinase mRNA. A new antibody (anti-tyrosinase, Clone T311, IgG2a type, Lab Vision Corporation) was used to detect nodal micrometastases. The search for micrometastases was histologically positive in 15 SNs and negative in 97. The 88 SNs examined using molecular biology were positive in 40 cases and negative in 48. In 28 only the PCR was positive. The new antibody used to detect micrometastases was shown to be very useful. Cases positive on both conventional histology and PCR were Clark level II or more and were thicker than 0.6 mm. No difference with regard to site or sex was observed. Lymphoedema and hypersensitivity reactions, nor the inability to work, did not occur. Only patients with histologically proven micrometastases underwent elective node dissection. Cases positive only on molecular biology were submitted to close follow-up.

Digital epiluminescence microscopy: usefulness in the differential diagnosis of cutaneous pigmentary lesions. A statistical comparison between visual and computer inspection.

Epiluminescence light microscopy (ELM) has been confirmed to be a useful tool for the diagnosis of pigmented skin lesions. The application of digital systems to epiluminescence represents the latest attempt to improve the diagnosis of cutaneous melanoma. The aim of this study was to compare the diagnostic accuracy of one of these systems, the DB-Dermo MIPS, with the accuracy of well-trained dermatologists using the ELM technique in order to establish the real usefulness of this instrument and to verify how much it can help the clinician make a diagnosis in a clinical setting. During a campaign for the early diagnosis of cutaneous melanoma, 311 patients with non-melanocytic lesions, common naevi, dysplastic naevi and melanomas underwent clinical diagnosis using ELM, computerized evaluation with DB-Dermo MIPS and skin biopsy. Sensitivity, specificity, true and negative predictive value were evaluated for epiluminescence and digital epiluminescence. Our study revealed that the inspection of pigmented skin lesions by digital epiluminescence has a better diagnostic accuracy than that of a trained dermatologist using the epiluminescence technique only. In our experience, this computerized system can play an essential role in the detection of early melanomas.

Critical effects of intense sun exposure on the expression of epiluminescence microscopy features of acquired melanocytic nevi.

BACKGROUND: Current knowledge of the histologic counterparts of epiluminescence microscopy (ELM) features in pigmented skin lesions is limited. As a particular aspect of this problem, the transient effects of intense sun exposure on the morphological characteristics of melanocytic nevi may influence the expression of ELM features as well as the demonstration of stable and consistent histologic correlates. OBSERVATIONS: Forty melanocytic nevi from 11 subjects living in Northern Italy were examined by digital ELM before and after 5 to 13 days of sun exposure at latitudes of 5 degrees north to 3 degrees south. A number of multifaceted changes were observed. In particular, 3 lesions showed the expression of some structures compatible with radial streaming, pseudopods, and gray-blue areas. These features are considered to have often severe histologic correlates. In a third image, obtained 5 to 6 weeks later, they showed partial or total regression. Another case showed a massive regression of the pigment network as a result of a progressive inflammatory reaction with marked asymmetry in the distribution of pigmentation. CONCLUSIONS: Digital ELM has the potential to detect subtle changes in the structure of nevi after intense sun exposure. The transient observation of certain ELM features often associated with severe histologic substrates casts doubts on the ability of ELM to characterize sun-exposed nevi by a single examination.

Diagnosis of cutaneous melanoma: accuracy of a computerized image analysis system (Skin View).

BACKGROUND/AIMS: Early diagnosis is essential for reducing the high mortality of CM (cutaneous melanoma). An expert dermatologist has a diagnostic accuracy of 85% but, in performing mass screening, the problem is to transfer the experience of a specialized centre to peripheral health clinics. Therefore, some computerized analysis systems were made. The aim of this paper is to compare the diagnostic accuracy of one such system, the Skin View System (SVS), to the accuracy of a well trained dermatologist in order to establish the real usefulness of the instrument and to verify how much it can help the diagnostic accuracy of the clinician in a dermatology setting. METHOD: During a campaign for the early diagnosis of CM, 176 patients with small and flat pigmentary lesions underwent clinical diagnosis, computerized analysis with SVS and skin biopsy. For clinical and computerized diagnosis, we evaluated sensitivity, specificity, true and negative predictive value. RESULTS: The statistical evaluation, in our study, reveals that the computerized system has a diagnostic accuracy lower than that of a trained dermatologist. CONCLUSIONS: This computerized system does not help the clinician in the diagnosis of pigmented lesions.

Dermatoscopy: usefulness in the differential diagnosis of cutaneous pigmentary lesions.

Dermatoscopy has been reported to give valid information in the differential diagnosis of cutaneous pigmentary lesions. Using a dermatoscopy Delta 10 Heine optotechnique, we evaluated 220 pigmented lesions during a health campaign for the early diagnosis of cutaneous melanoma and compared clinical and dermatoscopic diagnosis. Histologic diagnosis was carried out after removal of the lesions. Sensitivity, specificity, positive predictive value, negative predictive value and overall agreement were evaluated. In our experience clinical and dermatoscopic diagnosis gave similar results; sensitivity and specificity were slightly better for dermatoscopy than for clinical diagnosis. The agreement between clinical and dermatoscopic diagnosis was better in histologically negative lesions. Dermatoscopy is useful in the diagnosis of pigmentary lesions, but clinical diagnosis by experienced dermatological staff, is unreplaceable, especially during a health campaign for the early diagnosis of cutaneous melanoma.

p53 Protein expression in nevi and melanomas.

p53 Protein immunohistochemical expression is a wide-spread feature of the malignant phenotype; most melanomas are reported as p53 positive, while nevi are reported as p53 negative. We investigate a series of 75 benign nevi and 47 melanomas (40 primary and seven metastatic) to evaluate their pattern of p53 immunoreactivity with a panel of specific antibodies (PAb1801, PAb240, DO7, and CM1) in view of a possible diagnostic role of p53 immunostaining. Our results demonstrate that 15% of nevi show p53 immunoreactive nuclei (usually in less than 1% of the cells) and that 30% of melanomas show p53 immunoreactive nuclei (one case with 20% immunoreactive cells, six cases with 1% to 5% positive cells, and four cases with less than 1% positive nuclei). p53 Positivity was seen also in basal and suprabasal keratinocytes. p53 Positivity in nevi is at variance with literature data supporting that nevi are p53 negative. p53 Positivity in nevi and in epidermis may be related to mechanisms of DNA repair, apoptosis, or to a specific phase of the cell cycle. In our series, p53 expression in melanomas is not as frequent as reported in the literature. Population-based differences or differences in case selection and sample handling may account for the above discrepancies. The demonstration of p53 positivity in benign skin lesions greatly hinders the possibility of a diagnostic use of p53 immunostaining in dermatopathology.

Effectiveness of the health campaign for the early diagnosis of cutaneous melanoma in Trentino, Italy.

BACKGROUND: To reduce the mortality rate from cutaneous melanoma in Trentino, a health campaign for early diagnosis aimed at the general public was organized. OBJECTIVE: The mortality rate from cutaneous melanoma in Trentino before and after our health campaign was analyzed and compared with the mortality rates in three neighboring regions where no campaigns were carried out. METHODS: The mortality for cutaneous melanoma was analyzed using data from the death certificates provided by ISTAT for the pre- and postcampaign periods. The two summary methods: cumulative rate and the standard mortality ratio were used. RESULTS: The cumulative mortality rates in the neighboring regions show a tendency to increase over the three periods whereas the increase in Trentino is less evident. The standard mortality ratios confirmed this result. CONCLUSION: We feel that this type of campaign is to be recommended in the reduction of mortality from cutaneous melanoma.

Bath-photo-therapy with the thermal water of Comano: treatment of psoriasis.

Association between baths with the thermal water of Comano Springs and selective photo-therapy UVB (bath-photo-therapy) has proved to be effective in 94% of psoriatic patients with non-extensive disease. Therefore bath-photo therapy represents a valid alternative to traditional topical treatments and can be used as a adjuvant in the interval periods of the aggressive modern therapy.

Epidemiology of psoriasis: case-control study in the province of Trentino (preliminary reports).

In the province of Trento a case-control study on the main environmental risk factors for psoriasis has been performed. No correlation has been demonstrated between the investigated factors and psoriasis, with the exception of familial predisposition.