23 research outputs found

    Dynamic markers based on blood perfusion fluctuations for selecting skin melanocytic lesions for biopsy

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    Skin malignant melanoma is a highly angiogenic cancer, necessitating early diagnosis for positive prognosis. The current diagnostic standard of biopsy and histological examination inevitably leads to many unnecessary invasive excisions. Here, we propose a non-invasive method of identification of melanoma based on blood flow dynamics. We consider a wide frequency range from 0.005 – 2 Hz associated with both local vascular regulation and effects of cardiac pulsation. Combining uniquely the power of oscillations associated with individual physiological processes we obtain a marker which distinguishes between melanoma and atypical nevi with sensitivity of 100% and specificity of 90.9%. The method reveals valuable functional information about the melanoma microenvironment. It also provides the means for simple, accurate, in vivo distinction between malignant melanoma and atypical nevi, and may lead to a substantial reduction in the number of biopsies currently undertaken

    Multiple pyogenic granuloma of the penis in a four-year-old child: a case report

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    Pyogenic granulomas are common, acquired, benign vascular lesions of the skin and mucous membranes that can develop both spontaneously and traumatically. We present a unique case of a four-year healthy, uncircumcised boy with multiple pyogenic granuloma on the mucous face of the penis foreskin. Although penile multiple pyogenic granulomas have previously been described in adults, there are no reports of similar problems in children. In this patient, the pathogenesis of the lesions is probably trauma related as reported in the anamnesis. Therapeutic options are discussed

    ANTIOXIDANT SYSTEM IN SPOROBOLUS STAPFIANUS: CHANGES IN RESPONSE TO DESICCATION AND REHYDRATION

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    Changes in the amounts of ascorbic acid, dehydroascorbic acid and glutathione and in the levels of related enzyme activities were studied in Sporobolus stapjianus leaves, a desiccation-tolerant or resurrection plant, in response to desiccation and rehydration. Detached leaves of S. stapfianus were rapidly dried for 120 hr at 0% rel. hum. A 24 hr desiccation period was sufficient to achieve extremely low water contents (0.2%). Dried leaves were then rehydrated for 24 hr. The soluble-protein content decreased after drying but did not increase after rehydration without death ensuing. The enzymes related to the glutathione-ascorbate cycle reacted differently to the rapid water loss: dehydroascorbate reductase (EC 1.8.5.1) and glutathione reductase (EC 1.6.4.2) activities increased while ascorbate peroxidase (EC 1.11.1.11) activity decreased. All these enzymes resumed their activities after rehydration. Oxidative processes were intensified following desiccation and even more after rehydration: i.e. the H2O2 level and the dehydroascorbate/ ascorbate molar ratio increased in desiccated leaves and even more in rehydrated leaves, while the oxidized glutathione/reduced ghttathione molar ratio, which decreased in desiccated leaves, reached the control value with rehydration

    ANTIOXIDANT SYSTEM IN BOEA HYGROSCOPICA: CHANGES IN RESPONSE TO DESICCATION AND REHYDRATION

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    In leaves of Boea hygroscopica subjected to either rapid or slow dehydration and rehydration, the response to H2O2 production was studied by monitoring the changes in the amounts of ascorbic and dehydroascorbic acids as well as the amounts of reduced and oxidized glutathione and related enzyme activities. Boea hygroscopica is a resurrection plant in which drought tolerance depends on the rate of desiccation. For this reason, excised leaves of B. hygroscopica were subjected either to rapid or slow dehydration, by a 144-hr exposure to 0% or 80% relative humidity, respectively. Slowly dried leaves, rehydrated for 36 hr. were able to resume their activities completely, while rapidly dried leaves were not able to revive. After dehydration, H,02 production decreased both in slowly and in rapidly dried leaves, whereas the levels of total ascorbate and glutathione became two and 50 times as high, respectively, as in the control. During slow drying, reduced glutathione was oxidized, since its content in slowly dried leaves was 50% lower than in rapidly dried leaves. The levels of soluble proteins were found to be, respectively, five and six times as high in rapidly and slowly dried leaves as in the control and rehydrated leaves. The electrophoretic patterns of soluble proteins were similar in both dehydrated leaves, but different from control and rehydrated leaves, which also presented similar patterns. The specific activities of dehydroascorbate reductase (EC 1.8.5.1), glutathione rcductasc (EC 1.6.4.2) and ascorbate peroxidase (EC 1.11.1.11) also had the same values in both slowly and rapidly dried leaves. Following rehydration. oxidative processes were intensified: H,O, levels and the oxidation of ascorbate and glutathione mostly increased during this period in which the functioning of the ascorbate/glutathione cycle was induced
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