Comparison of blood neoangiogenesis and lymphatic vascularization in colorectal adenomas from patients with and without concomitant colorectal cancer

Blood and lymphatic vessel proliferation is essential for tumor growth and progression. Most colorectal carcinomas develop from adenomas (adenoma-carcinoma sequence) in a process due to accumulation of molecular genetic alterations. About 5% of adenomatous polyps are expected to become malignant, but data on the differential angiogenic patterns of these lesions in patients with and without concomitant cancer are missing. The aim of the present study is to compare the angiogenic and lymphatic patterns of adenomatous polyps from patients with and without sporadic cancer. Thirty adenomatous polyps (15 from patients with another principal malignant lesion, and 15 from patients without cancer) were submitted to immunohistochemical staining for CD105 (marker for neoangiogenesis) and D2-40 (marker for lymphatic endothelium). Microvessel density and total vascular area were determined by computer image analysis to quantify the immunostained and total areas, and to assess the number of microvessels. Adenomas from patients with carcinoma showed significantly higher values of total vascular area determined by immunostaining for CD105 (cutoff value = 4386 µm²; P = 0.019) and of lymphatic microvessel density determined by immunostaining with D2-40 (cutoff value = 11.5; P = 0.041) when compared with those from patients without cancer. The present data indicate a significant increase in blood microvascular area and in lymphatic microvascular counts in adenomas removed from patients with cancer.

Minimal doses of hydroxyurea for sickle cell disease

The use of hydroxyurea (HU) can improve the clinical course of sickle cell disease. However, several features of HU treatment remain unclear, including the predictability of drug response and determination of adequate doses, considering positive responses and minimal side effects. In order to identify adequate doses of HU for treatment of sickle cell disease, 10 patients, 8 with sickle cell anemia and 2 with Sbeta thalassemia (8SS, 2SBeta), were studied for a period of 6 to 19 months in an open label dose escalation trial (10 to 20 mg kg(-1) day(-1)). Hemoglobin (Hb), fetal hemoglobin (Hb F) and mean corpuscular volume (MCV) values and reticulocyte, neutrophil and platelet counts were performed every two weeks during the increase of the HU dose and every 4 weeks when the maximum HU dose was established. Reduction in the number of vasoocclusive episodes was also considered in order to evaluate the efficiency of the treatment. The final Hb and Hb F concentrations, and MCV values were significantly higer than the initial values, while the final reticulocyte and neutrophil counts were significantly lower. There was an improvement in the concentration of Hb (range: 0.7-2.0 g/dl) at 15 mg HU kg(-1) day(-1), but this concentration did not increase significantly when the HU dose was raised to 20 mg kg(-1) day(-1). The concentration of Hb F increased significantly (range: 1.0-18.1 per cent) when 15 mg HU was used, and continued to increase when the dose was raised to 20 mg kg(-1) day (-1). The final MCV values increased 11-28 fl (femtoliters). However, reticulocyte (range: 51-205 x 10(9)/l) and neutrophil counts (range: 9.5-1.3 x 10(9)/l) obtained at this dose were significantly lower than those obtained with 15 mg kg(-1) day(-1). All patients reported a decrease in frequency or severity of vasoocclusive episodes. These results suggest that a hydroxyurea dose of 15 mg kg(-1) day(-1) seems to be adequate for treatment of sickle cell disease in view of the minimal side effects observed and the improvement in laboratory and clinical parameters.