Chih-Yuan Chung

Acute and chronic arsenic poisoning associated with treatment of acute promyelocytic leukaemia

Seven relapsed and/or refractory acute promyelocytic leukaemia patients were treated by arsenic trioxide (As2O3). Four patients (4/7, 57%) achieved complete remission after one to three cycles of treatment and the most common acute side‐effect was fluid retention (in six patients, 86%), including weight gains and pleuro‐pericardial effusions. Evident polyneuropathy compatible with chronic arsenic toxicity was noted in two of the three patients who received As2O3 maintenance therapy and one of them had marked distal muscular atrophy. We suggest that As2O3 may be a useful salvage therapy for relapsed and refractory APL patients, but the acute or chronic arsenic toxicity should be carefully monitored.

Superwarfarin intoxication: hematuria is a major clinical manifestation

Since superwarfarin is popular and readily available in stores, it may cause intoxication or overexposure, which can result in coagulopathy or abnormal bleeding in humans and, thus, is an important public health problem. We report our clinical experience with superwarfarin intoxication. Nine patients, including eight patients who had histories of ingesting superwarfarin, were studied. Of the patients, hematuria occurred in eight. Laboratory tests among the nine patients showed extremely prolonged prothrombin times and activated partial thromboplastin times, which could be corrected to normal by mixing 1:1 with normal pooled plasma; they also had very low functional levels of factor II, VII, IX, X, and proteins C and S, but normal functional levels of factors V, VIII, fibrinogen, and anti-thrombin III. Large doses of vitamin K1 were needed for 3 months or more to treat and correct the coagulopathy among the patients. The majority of the patients presented with gross hematuria, suggesting that hematuria is probably a major clinical manifestation of superwarfarin intoxication. Prolonged use of large doses of vitamin K1 is needed for the treatment of superwarfarin intoxication.

Corticosteroid administration depresses circulating dendritic cells in ITP patients.

Idiopathic or immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by low platelet count resulting from antibody-mediated destruction of platelets. The production of these IgG anti-platelet autoantibodies is critically governed by T-lymphocytes which can be activated by antigen-presenting cells (APC) such as dendritic cells. We hypothesized that one of the mechanisms by which corticosteroid administration can suppress the immune system is to depress the number of circulating dendritic cells production in ITP patients. Dendritic cell population was measured in peripheral blood of three ITP patients before and after the administration of prednisone. Both counts of myeloid and lymphoid dendritic cells in the blood of ITP patients were greatly reduced after the administration of prednisone. The decrease in circulating dendritic cells is associated with the increase of platelets in circulation with the treatment of prednisone. These results suggest that corticosteroid therapy may decrease the effects of the autoantibody on platelets in ITP patients by reduce the number of circulating dendritic cells.

Hyperhomocysteinemia, deep vein thrombosis and vitamin B12 deficiency in a metformin-treated diabetic patient.

Vitamin B12 deficiency may be induced by long-term use of metformin, which may in turn lead to hyperhomocysteinemia. Thus, hyperhomocysteinemia may increase the risk of vascular thrombosis in diabetic patients, when metformin is used and a homozygous methylenetetrahydrofolate reductase (MTHFR) C677T mutation is present. We report a 65-year-old Taiwanese diabetic woman who was treated with metformin for 6 years and who had suffered from swelling of the left lower extremity for 3 months. Ascending venography confirmed the diagnosis of proximal deep vein thrombosis, while hyperhomocysteinemia, megaloblastic anemia caused by vitamin B12 deficiency, and a homozygous C677T mutation of the MTHFR gene were also found. She had no identifiable venous thrombotic risk factors other than hyperhomocysteinemia, which seemed to be caused by both MTHFR C677T homozygous mutation and vitamin B12 deficiency. With the substitution of insulin injection for metformin, short-term supplement of vitamin B12, and anticoagulant therapy for the deep vein thrombosis, her anemia and hyperhomocysteinemia recovered rapidly. The deep vein thrombosis also responded well. Our findings highly suggested the role of metformin in causing vitamin B12 deficiency, which may serve as an additional risk factor for venous thrombosis in diabetic patients. Our report also highlights the need to check vitamin B12 levels during metformin treatment.

Expression of CD80 and CD86 costimulatory molecules are potential markers for better survival in nasopharyngeal carcinoma

BackgroundB7 Costimulatory signal is essential to trigger T-cell activation upon the recognition of tumor antigens. This study examined the expression of B7-1 (CD80) and B7-2 (CD86) costimulatory molecules along with HLA-DR and the presence of infiltrating lymphocytes and dendritic cells to assess their significance in patients with nasopharyngeal carcinoma (NPC).MethodsExpression of CD80, CD86, HLA-DR, S-100 protein and the presence of infiltrating lymphocytes and follicular dendritic reticulum cells were immunohistochemically examined on the paraffin-embedded tissue blocks from newly diagnosed NPC patients (n = 50). The results were correlated with clinical outcome of patients.ResultsCD80 and CD86 were each expressed in 10 of 50 cases in which they co-expressed in 9 cases. Univariate analysis revealed that patients with CD80/CD86 expression had significantly better overall survival than those without it (P = 0.017), but after adjustment for stage, nodal status, and treatment, the expression of CD80/CD86 did not significantly correlate with overall survival. Expression of HLA-DR and the presence of infiltrating lymphocytes and dendritic cells did not appear to have impact on the survival of patients.ConclusionExpression of CD80 and CD86 costimulatory molecules appears to be a marker of better survival in patient with NPC.

Bloody Stool as the Presentation of Melanoma of Unknown Primary Origin

This is a report on a 78-year old patient with a history of scleroderma, presenting with fresh bloody stools for one month. Colonoscopy revealed black masses in the ascending colon and rectum and biopsy confirmed the diagnosis of malignant melanoma. Abdominal CT revealed metastasis to the liver and both adrenal glands. Positron emission tomography (PET) was conducted to locate the primary site but no lesions were found on the skin. Thus, the primary site of the malignant melanoma in this case remained unknown. The case report is followed by a literature review.

Coupling behavior of Cu-O2 layers in oxygen-deficient YBCO films and ultrathin YBCO films

We have measured the resistivity as a function of temperature in a magnetic field at various field angles θ for oxygen-deficient YBCO films and ultrathin YBCO films; θ is the angle between the crystalc axis and the direction of the magnetic field. The angular dependence of the critical field,Hc2, shows a cusplike behaviour at θ=90° for the oxygen-deficient 60 K YBCO films indicating that the Cu-O2 layers are two-dimensional in nature. BothTc versus θ in a constant field andHc2 as a function of θ show a plateau at θ=90° for 83 K (zero resistance) ultrathin YBCO films with a thickness of 20 units of the YBCO cell; these results indicate that there is a coupling between the Cu-O2 layers. The dimensionality of the Cu-O2 layers in oxygen-deficient YBCO films and ultrathin YBCO films is discussed in terms of the anisotropic Ginzburg-Landau model and the Tinkham thin-film model.