Synthesis and evaluation of novel rhodacyanine dyes that exhibit antitumor activity

Rhodacyanine dyes and several analogous delocalized lipophilic cations (DLCs) were synthesized and evaluated as novel antitumor agents. Rhodacyanine dye consists of two heteroaromatic rings such as thiazoles at both termini of the conjugate systems and 4-oxothiazolidine (rhodanine) in the middle of it. Compounds with such a unique double-conjugate structure were found to inhibit the growth of several tumor cell lines, such as colon carcinoma CX-1, and to exhibit relatively low toxicity against normal kidney cell line CV-1 (e.g., IC50(CX-1) = 50 nM, IC50(CV-1) = 17.3 microM; selectivity index = 346 for compound 5). These compounds were also found to be efficacious in the tumor-bearing nude mice model (e.g., against human melanoma LOX; T/C (%) = 168 for compound 5). Structural modifications on rhodacyanine, including deletion of a heteroaromatic ring involved in the merocyanine conjugate system and replacement of rhodanine with a structurally related moiety such as 4-oxoimidazolidine or 4-oxo-1,3-dithiolane, resulted in a loss of the selectivity and/or the activity. Our current structure-activity studies imply that the double-conjugate system with a rhodanine moiety is essential for the selective activity of rhodacyanine dyes, and we find this class of compounds as unique antitumor agents candidates.     

CO2 reforming of CH4 over Ni/Mg–Al oxide catalysts prepared by solid phase crystallization method from Mg–Al hydrotalcite-like precursors

Ni supported catalysts were prepared by the solid phase crystallization (spc) method starting from hydrotalcite (HT) anionic clay based on [Mg₆Al₂(OH)₁₆CO₃ ^2–]H₂O as the precursor. The precursors were prepared by the co-precipitation method from nitrates of the metal components, and then thermally decomposed, in situ reduced to form Ni supported catalysts (spc-Ni/Mg–Al) and used for the CO₂ reforming of CH₄ to synthesis gas. Ni²⁺ can well replace the Mg²⁺ site in the hydrotalcite, resulting in the formation of highly dispersed Ni metal particles on spc-Ni/Mg–Al. The spc-catalyst thus prepared showed higher activity than those prepared by the conventional impregnation (imp) method such as Ni/-Al₂O₃ and Ni/MgO. When Ni was supported by impregnation of Mg–Al mixed oxide prepared from Mg–Al HT, the activity of imp-Ni/Mg–Al thus prepared was not so low as those of Ni/-Al₂O₃ and Ni/MgO but close to that of spc-Ni/Mg–Al. The relatively high activity of imp-Ni/Mg–Al may be due to the regeneration of the Mg–Al HT phase from the mixed oxide during the preparation, resulting in an occurring of the incorporation of Ni²⁺ in the Mg²⁺ site in the HT as seen in the spc-method. Such an effect may give rise to the formation of highly dispersed Ni metal species and afford high activity on the imp-Ni/Mg–Al.     

Effect of Solute Clusters on Stress Relaxation Behavior in Cu-Ni-P Alloys

In this study, the ultrafine structures in Cu-P and Cu-Ni-P alloys have been characterized using a three-dimensional atom probe (3DAP) and transmission electron microscopy (TEM), and the stress relaxation behavior of these alloys has been explored. The results show that low-temperature annealing greatly improved the stress relaxation performance, especially in the Cu-Ni-P alloys. The presence of Ni-P clusters in the Cu-Ni-P alloys has been revealed. The overall improvement in properties has been analyzed in terms of variations in the dislocation density and solute atom cluster density within these materials. It is shown that clusters with small average spacing give rise to significant improvements in the stress relaxation performance, without requiring significant change in the dislocation density.     

eagle, a member of the steroid receptor gene superfamily, is expressed in a subset of neuroblasts and regulates the fate of their putative progeny in the Drosophila CNS

We isolated and characterized the eagle gene, encoding a member of the steroid receptor superfamily in Drosophila. In the central nervous system eagle RNA was expressed in a limited number of cells. During stages 10 and 11, eagle RNA expression was observed in four neuroblasts, NB2-4, NB3-3, NB6-4 and NB7-3. Except for NB6-4, eagle RNA expression reached a maximum at the very beginning of expression or in the period of neuroblast delamination. Weak eagle RNA expression was also observed in a few putative progeny of NB7-3 during stages, late 11 and 12. All eagle RNA in abdominal segments disappeared at stage 13. Using an eagle-kinesin-lacZ fusion gene as a reporter, the division, migration, and axonogenesis in eagle-positive cells and their derivatives were examined. At stage 14, several types of neural or glial cells were detected which include EG and EW interneurons joining to the anterior and posterior commissures, respectively. Lack of eagle expression caused altered axonogenesis in an appreciable fraction of eagle-Kinesin-LacZ-positive neurons. Some EG cells failed to acquire the neural fate or underwent an extremely delayed differentiation, while EW neurons produced neurites in abnormal directions, suggesting that eagle may play a critical role in development of the progeny of eagle-positive neuroblasts.     

Effects of radiotherapy determined by 11C-methyl-L-methionine positron emission tomography in patients with primary cerebral malignant lymphoma

Two cases of histologically proven primary cerebral malignant lymphoma were examined serially with positron emission tomography (PET) using 11C-methyl-L-methionine (11C Met). Lesions delineated by 11C Met accumulation extended beyond enhancing areas on either X-ray computed tomography (CT) or magnetic resonance imaging. High uptake of 11C Met accurately showed biologically active and residual tumours, at a time when disappearance of a contrast-enhancing lesion on CT seemed to indicate involution. PET provides valuable information on the extent of tumour and assessment of radiotherapy in malignant lymphoma.     

ON THE DRYING MECHANISM OF SHRINKAGE MATERIALS

Effects of moisture content on Liquid transport properties (Permeability and suction pressure) and mechanical properties (Young's modulus, yield stress and tensile strength) of drying shrinkage materials (Kibnshi, IIaido and mixed clay) were measured and a strong dependence was found. When glass beads are added to the Kibushi, permeability increase and Young's modulus and yield stress decrease in spite of the same suction pressure and tensile strength. Changes in local moisture content and stress during drying was calculated by using finite-element method, taking into account the stress gradient in addition to the pressure gradient due to osmotic suction.     

Microstructure, thermal properties and hardness of the CeMO3 (M=Al,Ga) synthesized by arc-melting method

Synthesis of CeMO₃ (M=Al,Ga) was attempted by the arc-melting method. In the case of M=Al, the arc-melted sample consisted typically of three regions CeAlO₃, CeO₂ and eutectic, mainly Al₂O₃. A similar texture was also observed for the case of M=Ga. Both CeAlO₃ and CeGaO₃ are crystallized in a tetragonal system (space group:P4/mmm). Lattice parameters of the tetragonal cell for CeAlO₃ and CeGaO₃ are a=0.37669(9) nm, c=0.37967(7) nm and a=0.3873(1) nm, c=0.3880(1) nm, respectively. According to thermal analysis, decomposition of 2CeMO₃+1/2O₂→2CeO₂+M₂O₃ occurs for CeAlO₃ and CeGaO₃ at about 1275°C and 833°C, respectively. The TG curve shows that the onset-temperature of oxidation for CeAlO₃ is at 1170°C and for CeGaO₃ is at 720°C. After TG-DTA measurement, both compounds are completely decomposed to starting materials. The value of the micro-Vickers hardness for the CeAlO₃ and CeGaO₃ is 9.0 (±0.2) GPa and 7.2 (±0.4) GPa, respectively.