Cellular characteristics of acute leukemia cells simultaneously expressing CD13/CD33, CD7 and CD19

Of 832 acute leukemia patients, including 580 acute myeloblastic leukemia (AML), 197 pre-B acute lymphoblastic leukemia (ALL) and 55 pre-T ALL, 26 cases (3.1%) of CD13/CD33+CD7+CD19+ acute leukemia were found. A total of 20 patients were diagnosed as AML, two as pre-B ALL and four as pre-T ALL. Based on the relative intensity of expression of CD7 and CD19, CD13/CD33+CD7+CD19+ acute leukemia patients were subclassified into three categories. Type I (CD7 > CD19) included ten AML and four pre-T ALL, having cellular characteristics similar to CD7+ AML and CD13/CD33+CD7+ ALL. Type II (CD7 < CD19) consisted of four AML with t(8;21) and two pre-B ALL. Type III (CD7 = CD19) included six AML. CD13/CD33+CD7+CD19+ acute leukemia frequently expressed stem cell associated molecules, such as CD34 (88.5%), HLA-DR (96.2%) and mRNA for MDR1 (72.2%), GATA-2 (87.5%) and SCL (25.0%). Simultaneous expression of cytoplasmic CD3 and myeloperoxidase in some leukemia cells implies that CD13/CD33+CD7+CD19+ acute leukemia cells have the potential to differentiate into various lineages. These data suggest that a small population of acute leukemia patients with distinct phenotype, CD13/CD33+CD7+CD19+ acute leukemia, may originate from hematopoietic stem cells.     

Single-transverse mode and stable-polarization operation underhigh-speed modulation of InGaAs-GaAs vertical-cavity surface-emittinglaser grown on GaAs (311) B substrate

We have demonstrated an oxide confinement vertical-cavity surface-emitting laser grown on a GaAs (311)B substrate, and achieved single-transverse mode and single-polarization operation in the entire tested current range. The threshold was 0.6 mA for a 2.7 μm×2.9 μm oxide aperture. Even under high-speed modulation up to 5 GHz, the device showed stable single-transverse mode and polarization. Sidemode suppression ratio and orthogonal polarization suppression ratio were over 30 and 10 dB, respectively     

Selenocysteine synthesis in mammalia: an identity switch from tRNA(Ser) to tRNA(Sec)

The mechanism of selenocysteine insertion into proteins is distinct from all other amino acids in all lines of descent in that it needs specific protein cofactors and a structurally unique tRNA(Sec). It is first aminoacylated with serine and further recognized among all other serylated serine isoacceptors by a selenocysteine synthase and is converted to selenocysteyl-tRNA(Sec). We present here the complete set of identity elements for selenylation of mammalian seryl-tRNA(Sec) and show that the transplantation of these elements into normal serine tRNA allows its selenylation. Four particular structural motifs differentiate eukaryotic tRNA(Sec) from normal tRNA(Ser): the orientation of the extra arm, the short 4 bp T psi C-stem, the extra long 9 bp acceptor-stem and the elongated 6 bp dihydrouridine-stem. Only the last two are essential and only together sufficient for selenocysteine synthesis, whereby the additional base-pairs of the acceptor-stem may be replaced by non-paired nucleotides. Each exchange of the first three structural motifs mentioned above between tRNA(Ser) and tRNA(Sec) resulted in a significant loss of serylation, indicating that the overall composition of particular structure elements is necessary to maintain normal functions of tRNA(Sec). Since we find that all seryl-tRNAs which are selenylated are also substrates for serine phosphorylation we propose that phosphoseryl-tRNA(Sec) is a storage form of seryl-tRNA(Sec).     

Microporous polypropylene hollow fibers containing poly(methylsilsesquioxane) fillers

Microporous polypropylene hollow fibers were prepared by stretching polypropylene microtubes containing poly(methylsilsesquioxane) fillers with uniform particle sizes. The properties of the resultant hollow fibers are controllable by adjusting the particle size of the filler, the filler content, and the stretching degree. Also, it is elucidated that the hollow fibers have a fine texture of split PP fibrils, in which the filler particles are dispersed. © 1994 John Wiley & Sons, Inc.     

Stabilizing control of power system using fuzzy control

This paper presents an application of fuzzy control to enhance power system stability. The proposed control consists of the controller for large disturbance (FU 1), the fuzzy controller for small disturbance (FU 2), and the fuzzy judgment mechanism (FU 3). FU 1 is determined based on the fuzzy controller [FU 1(F)] is determined according to the control rules and its input signals, i.e., speed deviation and acceleration at every sampling time of the machine. FU 2 consists of two controllers, namely, FU 2-ω and FU 2-P; FU 2-ω has the same mechanism as FU 1, while the output signal of FU 2-P is determined according to the rules together with the change of error of electrical power and terminal voltage. To obtain the optimal desired control signal during both the large and the small disturbances, the operations of FU 1 and FU 2 are judged by FU 3, where the magnitude of speed deviation is chosen as its input signal. The determined control signal is fed to AVR of the machine. The implementation of the proposed control is simple due to the small amount of calculations and required data. The effectiveness of the proposed control is demonstrated by the one-machine infinite-bus system model and very good system performance is obtained throughout all the simulations.     

Purification and characterization of a novel protein activator of Ca2+/calmodulin-dependent protein kinase I

A protein activator of Ca2+/calmodulin (CaM)-dependent protein kinase I was purified from rat brain. The activator was retained on a CaM-Sepharose column in the presence of Ca2+ and kinase assay of renatured gel revealed the 64 kDa molecule in the purified activator fraction to be autophosphorylated and to phosphorylate recombinant CaM kinase I in the presence of Ca2+/calmodulin. These results suggest that this activator of CaM kinase I is also a CaM-dependent protein kinase. Phosphorylation of CaM kinase I by the activator resulted in drastic potentiation of its CaM-dependent activity. Furthermore, kinetic analyses demonstrated that the activation decreases the Km values of CaM kinase I for both ATP and syntide-2 without a change in Vmax values. Considering the quite low enzymatic activity of recombinant CaM kinase I without activation, the 64 kDa species might be essential for CaM kinase I function in vivo.     

Continuous Processing of Monodispersed Titania Powders

A new continuous precipitation process for monodispersed ceramic powders using a static mixer was developed. Monodispersed TiO₂ powders were prepared continuously with high reproducibility and reliability by controlled hydrolysis of titanium ethoxide. Important steps were uniform and rapid mixing and aging using hydroxypropylcellulose as a dispersant. The concentrations of titanium ethoxide and water suitable to production of monodispersed TiO₂ powders lay within a limited range. A minimum aging period of 10 min was required to obtain monodispersed powders.     

Choline-sensing electrode based on polyethylene glycol-modified enzyme and mediator

Polyethylene glycol-modified choline oxidase (PEG—ChOD) has been prepared in order to construct choline-sensing carbon-paste electrodes: the PEG—ChOD and mediator, 1,1-dimethylferrocene, are incorporated into a carbon-paste matrix. The PEG—ChOD-based electrode exhibits higher enzyme activity than an electrode using native ChOD, since the PEG is effective in protecting ChOD from oil in the paste. The current response of the PEG—ChOD-based electrode is larger than that of the native ChOD-basedone for choline concentrations higher than 5 mM. The PEG—ChOD-based electrode is more stable than the native ChOD-based one. Coating the surface of the PEG—ChOD-based electrode with a cation polymer is effective in enhancing the current response to choline: the current response of the PEG—ChOD-based electrode coated with a layer of AQ-29D (Kodak) is about four times larger than that of the AQ-29D-free electrode.