Signaling molecule methylglyoxal ameliorates cadmium injury in wheat (Triticum aestivum L) by a coordinated induction of glutathione pool and glyoxalase system.

Methylglyoxal (MG) now is found to be an emerging signaling molecule. It can relieve the toxicity of cadmium (Cd), however its alleviating mechanism still remains unknown. In this study, compared with the Cd-stressed seedlings without MG treatment, MG treatment could stimulate the activities of glutathione reductase (GR) and gamma-glutamylcysteine synthetase (γ-ECS) in Cd-stressed wheat seedlings, which in turn induced an increase of reduced glutathione (GSH). Adversely, the activated enzymes related to GSH biosynthesis and increased GSH were weakened by N-acetyl-L-cysteine (NAC, MG scavenger), 2,4-dihydroxy-benzylamine (DHBA) and 1,3-bischloroethyl-nitrosourea (BCNU, both are specific inhibitors of GR), buthionine sulfoximine (BSO, a specific inhibitors of GSH biosynthesis), and N-ethylmaleimide (NEM, GSH scavenger), respectively. In addition, MG increased the activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) in Cd-treated seedlings, followed by declining an increase in endogenous MG as comparision to Cd-stressed seedlings alone. On the contrary, the increased glyoxalase activity and decreased endogenous MG level were reversed by NAC and specific inhibitors of Gly I (isoascorbate, IAS; squaric acid, SA). Furthermore, MG alleviated an increase in hydrogen peroxide (H2O2) and malondialdehyde (MDA) in Cd-treated wheat seedlings. These results indicated that MG could alleviate Cd toxicity and improve the growth of Cd-stressed wheat seedlings by a coordinated induction of glutathione pool and glyoxalase system.

Multiple-image optical encryption: an improved encoding approach.

An improved encoding approach to multiple-image optical encryption based on a cascaded phase retrieval algorithm (CPRA) is proposed. The system consists of several stages of a standard 4-f correlator, in which the keys are not only the phase mask pairs produced by CPRA but also the phase distribution of the output plane of the front stage. The security and the capacity of the system are also discussed. Results indicate that the system can resist known-plaintext attack to some extent, and the encrypted capacity is considerably enhanced. Computer simulations have proved the validity of the proposed idea. The system can be implemented using a pure optical architecture.

Transformation of myelodysplastic syndromes into acute myeloid leukemias.

BACKGROUND: Myelodysplastic syndromes (MDSs), also called preleukemias, are a group of myeloid hematopoietic malignant disorders. We studied the transformation of MDS into acute myeloid leukemia (AML). METHODS: Leukemic transformation in 151 patients with MDS was dynamically followed up. The clinical manifestation, peripheral blood and bone marrow condition, karyotypes, immunophenotypes, response to treatment, and prognosis of AML evolution from MDS (MDS-AML) were also observed. RESULTS: During the course of this study, over the past eight years and seven months, 21 (13.91%) of 151 MDS patients progressed to overt leukemia, with a median interval of 5 (1 - 23) months. There were no significant differences between rates of leukemic transformation in comparison with the refractory anemia (RA), RA with excess of blasts (RAEB), and RAEB in transformation (RAEB-t) patient groups. Transformation occurred either gradually or rapidly. There were five parameters positively correlated to leukemic transformation: under 40 years of age, pancytopenia of 3 lineages, more than 15% blasts in the bone marrow, at least two abnormal karyotypes, and treatment with combined chemotherapy. All of the 21 patients with leukemia suffered from MDS-AML, and most of them were M2, M4, or M5. Two (9.52%) MDS-AML patients developed extramedullary infiltration. Leukopenia was found in 47.62% of these patients. Two thirds of these patients, whose bone marrows were generally hypercellular, suffered from neutropenia. After developing AML, 8 (47.06%) patients developed abnormal karyotypes. High expression of immature myeloid antigens, including CD33 [(49.83 +/- 24.50)%], CD13 [(36.38 +/- 33.84)%], monocytic antigen CD14 [(38.50 +/- 24.60)%], and stem cell marker CD34 [(34.67 +/- 30.59)%], were found on bone marrow mononuclear cells from MDS-AML patients after leukemic transformation. In some cases, lymphoid antigens, such as CD5, CD7, CD9, and CD19, coexisted with myeloid antigens. A low complete remission rate (31.25%) and a short survival time, with median survival of 6 (1 - 28) months, were found in patients with MDS-AML treated by induction chemotherapy. CONCLUSIONS: MDS has a high risk of developing into AML, either gradually or rapidly. Patients with MDS-AML have specific biological characteristics and a worse prognosis.