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BACKGROUND: Development of more than one primary melanoma in a patient is a relatively uncommon but well-recognized phenomenon. Its frequency has ranged from 1.2% to 8.2% in several series. This subgroup of patients with multiple primary lesions has not been characterized sufficiently. We report the experience of the Melanoma Unit of University Hospital Spedali Civili of Brescia, Italy. METHOD: Study subjects were drawn from 1240 patients with histologically confirmed melanoma, including melanoma in situ. From this group, multiple melanomas developed in 47 patients (3.79%). Every one of our patients has been taught to perform self-examination of the skin to detect suspicious pigmented lesions. RESULTS: Of the 47 patients described in this study, 38 had two primary melanomas, 7 had three melanomas and 2 had 5 and 10 melanomas, respectively. Mean age at first diagnosis was 46.2 years. The majority of subsequent melanomas (74.5%) were removed within 5 years of the initial operation. Synchronous lesions were found in 10 patients. In male patients, the lesion appeared most frequently on the trunk; in female patients, melanoma appeared mostly on the lower extremities. The second primary melanomas developed in the same anatomic region from the first in 53.2% of our patients. The proportion of in situ to invasive melanomas was greater for the second melanomas compared with the first melanomas. Regarding invasive melanomas, the mean thickness of the first melanomas was 1.31 mm compared with 0.66 mm for the second ones. Dividing patients into two groups, of more and less than 50, it is highlighted that in older patients synchronous lesions appear more frequently (36.4% vs. 8.0%); the median time interval between sequential melanomas is longer (84 vs. 63.7 months); and the ratio between the primary and secondary melanoma mean thickness is lower (1.21 : 1.08 vs. 1.43 : 0.63 mm). CONCLUSIONS: The study confirms that second primary melanoma is usually thinner than the first lesion, and it is more common in the same region of the body as the initial melanoma. The highest risk for a second melanoma is during the first 5 years, but a much longer time interval of 28 years is possible. Continued medical follow-up with complete skin examinations seems prudent, but it is very important to promote self-skin evaluation in patients to detect not only metastases but also subsequent primary melanomas in their earliest phases.  相似文献   
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The optical properties of pig heart tissue were measured after in vivo ablation therapy had been performed during open-heart surgery. In vitro samples of normal and ablated tissue were subjected to measurements with an optically integrating sphere set-up in the region 470–900 nm. Three independent measurements were made: total transmittance, total reflectance and collimated transmittance, which made it possible to extract the absorption and scattering coefficients and the scattering anisotropy factor g, using an inverse Monte Carlo model. Between 470 and 700 nm, only the reduced scattering coefficient and absorption could be evaluated. The absorption spectra were fitted to known tissue chromophore spectra, so that the concentrations of haemoglobin and myoglobin could be estimated. The reduced scattering coefficient was compared with Mie computations to provide Mie equivalent average radii. Most of the absorption was from myoglobin, whereas haemoglobin absorption was negligible. Metmyoglobin was formed in the ablated tissue, which could yield a spectral signature to distinguish the ablated tissue with a simple optical probe to monitor the ablation therapy. The reduced scattering coefficient increased by, on average, 50% in the ablated tissue, which corresponded to a slight decrease in the Mie equivalent radius.  相似文献   
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Aim: The purpose of this study was to assess objectively the ultrastructure of the secretory granules in rabbit conjunctival mucin‐producing ‘goblet’ cells. Method: The upper eyelids from five young adult dioestrous female rabbits were dissected out, stretched onto a cardboard support and prepared for transmission electron microscopy by repeated application of an isotonic two per cent glutaraldehyde fixative at room temperature. Post‐fixation treatment included osmium tetroxide and staining with uranyl acetate and lead citrate. Low magnification micrographs were taken of the goblet cells of the conjunctiva, printed at a magnification of approximately 6,000 and the number, size and features of the secretory granules assessed. Results: Across the entire palpebral conjunctiva of ail five rabbits, the majority of mucous cells displayed a goblet shape and the secretory granules were uniformly pale in staining. The average width of the goblet cells was 10.8 ± 1.1 μm and the diameter of the secretory granules was 0.82 ± 0.16 μm. However, in localised regions across the palpebral conjunctiva of two of the rabbits, some goblet cells were different in that the secretory granules had either a denser‐staining core, in which some of the granules were densely staining (while others were pale) or most of the granules were densely staining. These mucous cells had an average diameter of 10.3 ± 1.7 μm and the granule diameters averaged 0.88 ± 0.01 μm. For these abnormal goblet cells, inflammatory cells were found in their immediate vicinity. Occasionally, goblet cells were seen to be in the process of degranulation with associated apparent cell necrosis and the mucin granule diameter was close to 1 μm. Conclusions: The ultrastructure of the mucin‐containing secretory granules of the conjunctival mucous cells is not necessarily homogeneous in character and further attention needs to be given to the effects of localised inflammation in the tissue and to possible hormonal influences.  相似文献   
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γ-去氢骆驼蓬碱等咔啉类生物碱的辐射防护作用   总被引:8,自引:0,他引:8  
γ- Harmine(Ⅰ),’harmine(Ⅱ )and harmaline(Ⅲ )were isolated from PeganumHarmala L.( Zygophylaceae).Tests were conducted with mice to detect whether γ- harmine( a newcompound), harmine,harmof(Ⅳ)and harmalol(Ⅴ) are effective radioprotective compounds againstγ-ray irradiation, Intraperitoneal injection of the hydrochlorides of the four alkaloids 50~80mg·kg-1×1 in NIH male mice 30~45 minutes before 8.6~9. 7 Gy whole body 60Co irradiationsignificantly increased the survival effects(1. 33~2. 61)and 30-day survivai rate in comparison withcontrol mice.The results indicatethat γ- harmine exhibited relatively good radioprotective effect.γ-harmine is the first alkaloid isolated from a plant having ptotective effects against whole-body lethal irradiation in mice.  相似文献   
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