Melanocytic Nevus with Atypical Dermoscopic Features at the Site of Radiodermatitis

BACKGROUND: Radiation therapy can cause acute and chronic damage of the skin. OBJECTIVE: A 71-year-old woman presented with an atrophic and sclerotic plaque at a site previously treated with radiotherapy because of lung cancer. Inside the area affected by chronic radiodermatitis, she reported that a preexisting pigmentary lesion had gradually undergone morphologic changes after radiation therapy. MATERIALS AND METHODS: On dermoscopy, the lesion showed features highly suspicious for malignant melanoma. The lesion was excised and examined histopathologically. RESULTS: The histopathologic diagnosis was compound congenital melanocytic nevus associated with prominent dermal sclerosis and epidermal atrophy. CONCLUSIONS: The existence of melanocytes within an atrophic and fibrotic area is a finding typically associated with recurrent or persistent melanocytic lesions. It is likely that the "pseudomelanoma" features of the lesion observed in our patient might have been secondary to the skin changes induced by radiation therapy.     

Exercise induced increase in diastolic blood pressure. Is it an indicator of coronary artery disease?

It has been previously reported that an increase in diastolicblood pressure greater than 15 mmHg comparing values at restwith those on treadmill exercise, with or without ST changes,enhances the probability of coronary artery disease. To investigatewhether the diastolic blood pressure variation keeps its diagnosticvalue during upright bicycle exercise, we evaluated the diastolicblood pressure variations in 111 patients with angiographicallydocumented coronary artery disease without previous myocardialinfarction and in 53 patients with normal coronary arteriesundergoing maximal stress testing on a bicycle ergometer. Thesensitivity of diastolic blood pressure (DBP) variations todetect coronary artery disease was 66%, the specificity 32%,the positive predictive value 67%, the negative predictive value31% and the predictive accuracy 55%. The respective values forST depression were 83% (P<0·001 vs DBP variations),53% (P<0· vs DBP variations), 64% (P<0·05vs DBP variations) and 75% (P<0·001 vs DBP variations). Forty-nine of the 75 patients with multivessel coronary arterydisease and 60 of the 89 patients without coronary artery diseaseor with single vessel disease had abnormal DBP variations (sensitivity65; spec 33%). The sensitivity of ST segment depression in predictingmultivessel disease was 91% (P<0·001 vs DBP variations),and the specficity 42%. Thus for bicycle ergometer exercise testing, ST segment depressionseems to be more accurate than DBP variations in the diagnosisof coronary artery disease.     

药品安全性证据分级分类探索研究——构建中药上市后安全性证据体

借鉴循证医学既有证据分类、分级的成功经验,探索中药上市后安全性证据评价、分类和分级标准并形成安全性证据评价的基本框架,从点、线、面、体多个角度综合不同证据源,构建中药上市后安全性证据体,为今后该领域证据体系的研究提供方法学和技术支撑。     

Dynamic interaction between Leishmania infection in mice and Th1-type CD4+ T-cells: complexity in outcome without a requirement for Th2-type responses

The interaction between Leishmania parasites and Th1 cells is investigated using a simple mathematical model of immunological responses and parasite population growth within the host. The model generates patterns of resistance and susceptibility to infection that mirror observed trends in experimental infections of mice and of humans exposed to infection in areas of endemic transmission. The heterogeneity in outcome predicted by the model can arise either through differences in the values of the parameters that characterize the genetic background of the host or as a consequence of differences in the size of the infecting inoculum of the parasite. Detailed analyses of equilibrium states and of the time course of infection within a host suggest that a limitation in the availability of precursor T-cells, as a consequence of high levels of recruitment into the activated pool, may play a signficant role in the progression of infection in susceptible hosts. A brief discussion is presented of the implications of model prediction for therapeutic intervention.     

p53 tumour suppressor gene and RAS oncogenes: molecular analysis in the chronic and leukaemic phases of essential thrombocythaemia

A panel of 51 cases of essential thrombocythaemia (ET), in chronic or leukaemic phase, was investigated for p53 gene and RAS oncogenes mutations by PCR-SSCP-direct sequencing. No RAS oncogenes mutations were detected, but p53 mutations were identified in three cases: 1/27 cases (≈4%) in chronic phase not undergoing chemotherapy, 1/19 cases (≈5%) in chronic phase undergoing chemotherapy, and 1/5 cases (20%) which had progressed to leukaemia. Our results suggest that: (1) p53 gene mutations occur sporadically in the chronic phase of ET, independent of chemotherapy, and may contribute to the progression to the leukaemic phase in a limited number of ET patients; (2) the RAS genes family does not seem to be involved in the pathogenesis of ET, unlike other bcr/abl negative chronic myeloproliferative diseases (CMPDs).