Application of the Extended Corresponding States Method to the Calculation of the Ammonia–Water Mixture Thermodynamic Surface

The paper presents an application of the one-fluid extended corresponding states method to the calculation of the thermodynamic surface of the ammonia–water mixture. Each pure component of the mixture is considered as a reference fluid, and to test the behavior of the model in wide ranges of temperature and pressure, the Haar–Gallagher and the Pruß–Wagner equations of state were chosen for pure ammonia and water, respectively. To avoid numerical problems during the calculation of the pure-component equivalent substance reducing ratios (or scaling factors), a method based on the mapping defined by the extended corresponding states algorithm and two-dimensional interpolation is proposed. The estimation of the binary interaction parameters was performed using the general case of the least squares method, i.e., the case when all measurements (observations) and unknowns are subject to uncertainty and are adjusted simultaneously with the constraint equations. The results show a strong temperature and composition dependence of both interaction parameters for the liquid, as well as for the vapor phase. A formulation for the binary interaction parameters as continuous functions of these variables was also derived and optimized using the structural optimization and regression analysis. The final statistical quality of the approach presented in the paper was assessed using the available data on thermophysical properties of the mixture.     

The effect of air exposure on the photocurrent in a conjugated platinum poly-yne

We present photocurrent spectra of an ITO/Pt-poly-yne/Al photocell under vacuum after annealing and also after exposure to air. We find that air enhances exciton dissociation. We also find that a low energy photocurrent tail appears after exposure of the cell to air. The enhancement of the photovoltaic response to air is found to be reversible after annealing under vacuum.     

The LMO1 and LDB1 proteins interact in human T cell acute leukaemia with the chromosomal translocation t(11;14)(p15;q11)

The ectopic expression of LMO1 or LMO2 in T cell acute leukaemias resulting from chromosomal translocations t(11;14)(p15;qll) or t(11;14)(p13;q11) respectively in a causal factor in tumorigenesis. LMO1 has been found as a heterodimer with a 46 Kd protein in a T cell line derived from a childhood T-acute leukaemia. This 46 Kd protein is the LIM-binding protein LDB1/NLI. The latter is a phosphoprotein and binds to LMO1 in its phosphorylated state and essentially all the LMO1 and LDB1 protein in the T cell line is part of the complex. Therefore, the LMO1-LDB1 interaction is likely to be involved in tumorigenesis after LMO1 is ectopically expressed following chromosomal translocation in T cells prior to development of acute leukaemias.     

ATP- and gap junction-dependent intercellular calcium signaling in osteoblastic cells

Many cells coordinate their activities by transmitting rises in intracellular calcium from cell to cell. In nonexcitable cells, there are currently two models for intercellular calcium wave propagation, both of which involve release of inositol trisphosphate (IP3)- sensitive intracellular calcium stores. In one model, IP3 traverses gap junctions and initiates the release of intracellular calcium stores in neighboring cells. Alternatively, calcium waves may be mediated not by gap junctional communication, but rather by autocrine activity of secreted ATP on P2 purinergic receptors. We studied mechanically induced calcium waves in two rat osteosarcoma cell lines that differ in the gap junction proteins they express, in their ability to pass microinjected dye from cell to cell, and in their expression of P2Y2 (P2U) purinergic receptors. ROS 17/2.8 cells, which express the gap junction protein connexin43 (Cx43), are well dye coupled, and lack P2U receptors, transmitted slow gap junction-dependent calcium waves that did not require release of intracellular calcium stores. UMR 106-01 cells predominantly express the gap junction protein connexin 45 (Cx45), are poorly dye coupled, and express P2U receptors; they propagated fast calcium waves that required release of intracellular calcium stores and activation of P2U purinergic receptors, but not gap junctional communication. ROS/P2U transfectants and UMR/Cx43 transfectants expressed both types of calcium waves. Gap junction-independent, ATP-dependent intercellular calcium waves were also seen in hamster tracheal epithelia cells. These studies demonstrate that activation of P2U purinergic receptors can propagate intercellular calcium, and describe a novel Cx43-dependent mechanism for calcium wave propagation that does not require release of intracellular calcium stores by IP3. These studies suggest that gap junction communication mediated by either Cx43 or Cx45 does not allow passage of IP3 well enough to elicit release of intracellular calcium stores in neighboring cells.     

Heat shock cognate protein 71-associated peptides function as an epitope for Toxoplasma gondii-specific CD4+ CTL

HLA-DR-restricted CD4+ cytotoxic T-lymphocyte (CTL) lines specific for Toxoplasma gondii (T. gondii)-infected melanoma cells have been established from peripheral blood lymphocytes (PBLs) of a patient with chronic toxoplasmosis. The role of heat shock cognate protein (HSC) 71 in antigen (Ag) processing and presentation of T. gondii-infected melanoma cells to these CD4+ CTL lines was investigated. A human melanoma cell line (P36) pulsed with T. gondii-infected P36 cell-derived HSC71 was lysed by a T. gondii-specific CD4+ CTL line (Tx-HSC-1). The Tx-HSC-1 also killed T. gondii-infected P36 cells. The lytic activity of Tx-HSC-1 against P36 cells pulsed with T. gondii-infected P36 cell-derived HSC71 was inhibited by monoclonal antibodies (mAbs) against HSC71. Anti-human leukocyte antigen (HLA)-DR mAb also partially blocked the lytic activity, whereas anti-HLA-A,B,C mAb did not block the lytic activity. In addition, a flow cytometric analysis with these specific mAbs against HSC71 showed HSC71 to be expressed on the cell surface of T. gondii-infected P36 cells as well as uninfected P36 cells. These data indicate that HSC71 molecules are expressed on human melanoma cell line P36, and that HSC71 may play a potential role in Ag presentation and processing of T. gondii-infected P36 cells to CD4+ CTL.     

Randomized, double blind, dose-response trial across four oral doses of dolasetron for the prevention of acute emesis after moderately emetogenic chemotherapy. Oral Dolasetron Dose-Response Study Group

BACKGROUND: This double blind parallel group study assessed the acute antiemetic efficacy of four oral doses of dolasetron mesylate in cancer patients receiving their first course of intravenous chemotherapy with doxorubicin and/or cyclophosphamide. METHODS: Patients were randomized to receive 25, 50, 100, or 200 mg of dolasetron mesylate 30 minutes prior to chemotherapy and were monitored for nausea and emetic episodes for the next 24 hours. RESULTS: Three hundred and nineteen cancer patients at 32 sites completed the study. Most patients were female (81%); of this group, 69% had breast carcinoma. A highly statistically significant linear trend demonstrating improved response with higher doses was detected for complete response (no emetic episodes and no rescue medication) (P < 0.001), for complete plus major response (0-2 emetic episodes and no rescue medication) (P < 0.001), and for patient visual analog scale assessments of nausea (P = 0.001) and general satisfaction with antiemetic therapy (P = 0.001). No serious adverse events were noted. The most frequent adverse event was mild, self-limiting headache, which has been reported with other drugs in this class. CONCLUSIONS: Single oral doses of dolasetron mesylate were found to be effective in preventing acute emesis in cancer patients receiving moderately emetogenic chemotherapy.