Allogenic transplantation of hematopoietic stem cells in the treatment of children with high-risk acute leukemia

BACKGROUND: Most children with acute lymphoblastic leukemia (ALL) and increasing number of children with acute myelogenous leukemia (AML) are currently cured with conventional chemotherapy. Despite of this success there is a subset of patients with high-risk features at diagnosis who are predisposed to a very high risk of relapse. Relapse of AML and early bone marrow relapse of ALL can not be cured by conventional chemotherapy. Allogeneic hematopoietic stem cell transplantation (HSCT) is therapeutic option in these children with very high-risk acute leukemia. METHODS AND RESULTS: Between XI/1989-XII/1996 33 children with acute leukemia (ALL: 22, AML: 11) underwent an allogeneic HSCT from HLA identical related donors (HLA-identical sibling: 30, twin: 1, other HLA-identical relative: 2) at the 2nd Dept. of Pediatrics, University Hospital Motol. Median age of our group was 9 years (1.5-19 y.), boys (n = 23) clearly dominated over the girls (n = 10). The resource of stem cells was bone marrow in 31 children, bone marrow and peripheral blood progenitor cells (PBPC) and PBPC in one child respectively. Myeloablative conditioning regimen varied, consisting of total body irradiation and chemotherapy in 21 children and chemotherapy in 12 children. HSCT was performed in first complete remission of acute leukemia in 9 children (AML: 7, ALL: 2), in second remission in 14 children (AML: 2, ALL: 12), in third remission in 4 children (ALL: 4). Six children underwent HSCT in first partial remission (n = 1) and in second (n = 4) or third (n = 1) chemoresistant relapse. Seven (21%) children died due to post-transplant complications. Nine (28%) children suffered from clinically significant acute graft-versus-host reaction (GVH) and 15% (4/27) children who survived 100 days post-transplant suffered from chronic GVH disease. Relapse of leukemia was diagnosed in 39% (12/31) children. Fourteen (42%) children are alive and well in continuous remission with median follow-up 42 months. CONCLUSIONS: Allogeneic HSCT can cure children with very high-risk acute leukemia in the situations where conventional chemotherapy fails. Relapse of leukemia and GVH reaction are most important causes of post-transplant morbidity and mortality.     

Effects of ohmic heating for pre-cooking of meatballs on some quality and safety attributes

Effectiveness of ohmic treatment on some quality attributes of semi-cooked meatballs was studied. Meatball samples were semi-cooked by 15.26 V/cm voltage gradient and 0 s holding time at 75 °C. Although ohmic cooking significantly reduced the numbers of total mesophilic aerobic bacteria, mould-yeast, Staphylococcus aureus and completely eliminated Salmonella spp. from meatball samples (p < 0.05), it was not found efficient to inactivate all Listeria monocytogenes cells. Ohmic semi-cooking process was resulted at higher cooking yields, which were supported by high fat and moisture retention values in meatball samples. Metal levels (iron, chromium, nickel and manganese) of ohmically semi-cooked meatball samples were found below the upper level of dietary exposure levels. Ohmic cooking procedure was found to be safe in terms of PAH formation and mutagenic activity. Sensory evaluation showed that the overall acceptance of the semi-cooked meatball samples were good. These results demonstrate considerable potential for the application of ohmic process for semi-cooking of meatballs.     

Experimental characterization and modeling of the mechanical properties of Cu-Cu thermocompression bonds for three-dimensional integrated circuits

An analytical model is proposed which relates the bonding temperature, pressure and duration with the integrity of metal-metal thermocompression bonds. Unlike previous models, this approach takes into account the pressure-dependent time evolution of the thermocompression bond formation. The model allows calculation of the true contact area of rough surfaces, based on a creep-dominated plastic deformation. Verification of the model was provided through experiments on Cu-Cu thermocompression bonds of electroplated Cu on diced silicon wafers with chemically/mechanically polished surfaces. The samples were bonded at a range of temperatures, pressures and times. Shear strength measurements were used to characterize the effects of the bonding parameters on the interface bond strength. Calculated true contact area and bond shear strength can be related by a single proportionality factor. The model can be used to predict the thermocompression bond quality for given bonding parameters and process optimization for reliable bonds, thus assisting in the adoption of the Cu thermocompression bond process in three-dimensional integrated circuit applications.     

Stable electrotransformation of symbiont candidate diazotrophic bacterium with plasmids carrying selectable and screenable marker genes

Fluid and sodium retention with peripheral oedema and ascites are often seen in decompensated patients with diseases of the liver, kidney and heart and in malignancies. Despite a careful clinical examination including relevant biochemical tests, decompensation is associated with diagnostic challenges. Two cases are presented where a haemodynamic investigation of the splanchnic and systemic circulation contributed to the establishment of a correct diagnosis, and the advantages of this diagnostic tool are discussed.     

Phase instability of manganese-iron carbides

The stability of carbon saturated manganese-iron alloys was studied by means of simulated decrepitation tests, and it was found that the product must contain a minimum of about 5 wt pct iron to be stable during storage. By means of several experimental techniques it was shown that the structure of the carbide phase present in carbon saturated ferromanganese determines whether the alloy is stable. Below the critical iron content of about 5 wt pct, the carbide phase is Hāgg carbide (MnFe)₅C₂, whereas above about 5 wt pct iron the carbide phase is cementite (MnFe)₃C. The role of iron is to stabilize the cementite phase. Experiments with the synthetic manganese carbides, Mn₅C₂ and Mn₃C, showed that the former reacts readily with water whereas the latter is stable.     

Vaporization of iron and phosphorus from iron-phosphorus melts in oxygen-bearing gas streams

Experiments have been made to demonstrate that when an oxygen-bearing gas is blown on the surface of iron-phosphorus melts, iron and phosphorus vaporize at rates enhanced by vapor-gas phase reactions. These findings are in accord with the theoretical predictions. The reaction mechanism considered is based on the concept of vaporization of phosphorus at the surface of iron as volatile PO and PO₂, which then react with iron vapor and oxygen in the gas close to the surface of the melt. If powdered lime were present, as in the Q-BOP, a relatively stable calcium phosphate would form, thus bringing about dephosphrization. From the available thermodynamic data and reaction-equilibrium data, equilibrium constants have been derived for the reaction of PO and PO₂ with liquid iron.     

Sulfides and oxides in Fe−Mn alloys: Part I. Phase relations in Fe−Mn−S−O system

This is a critical review of available equilibrium data between phases involving Fe, Mn, S, and O. Using the Morey-Williamson theorem, and that modified by Darken, the sulfur and oxygen potential diagrams are constructed for the Fe?S?O system involving nine univariant and three invariant equilibria. The solubility of sulfur in wustite-saturated iron is evaluated; the sulfur content of iron in equilibrium with wustite and liquid oxysulfide reaches a maximum of 143 ppm at 1200°C; this is about one half of that corresponding to the solidus of the Fe?S system. An estimate is made of the phase equilibria in the Fe?Mn?S?O quaternary system involving gamma iron and Mn(Fe)O phases. There is a eutectic invariant at ～900°C, and the liquid miscibility gap invariant is estimated to be at ～1225°C. From the expected phase relations and equilibria, it is deduced that if sufficient oxygen and sulfur,i.e. Mn(Fe)O and Mn(Fe)S phases, are present in Fe?Mn alloys, there may be a liquid oxysulfide phase present at temperatures above 900°C, depending on the concentration of manganese in solution. The higher the manganese content in solution, the higher is the temperature above which a liquid phase is present,e.g. for 10 ppm Mn, 900°C and for ～90 pct Mn, ～1225°C. A mechanism is suggested for the precipitation of sulfides and oxysulfides near the surface of steel during heating in an oxidizing atmosphere. In the Appendix by Darken and Gurry, results are given of the melting temperatures of mixtures of wustite and pyrrhotite in equilibrium with iron, from an investigation carried out about thirty years ago.     

The AISI steel initiative

This paper briefly describes the history, the purpose and the present status of the “AISI Steel Initiative”. The American Iron and Steel Institute (AISI) started a cooperation between universities and steel industry to investigate new steelmaking processes. A concept for in-bath smelting reduction has been developed.     

Equilibria between liquid Mn-Si alloys and MnO-SiO2-CaO-MgO slags

The activity of silicon in manganese-silicon melts was determined at 1500°C. The results are in general agreement with the thermodynamic data of the iron-silicon system. Equilibria between manganese-silicon melts and slags containing MnO, SiO₂, CaO, and MgO were studied at 1400 and 1500°C in silica and magnesia crucibles. An empirical relationship easy to use in practice was derived, expressing the manganese and silicon distribution ratio between slag and metal as a function of the slag basicity. This relationship describes equilibria pertinent to the silicothermic reduction of manganese oxide and the production of silicomanganese. The present knowledge of the activities in the slag and metal phase is adequate to explain the experimental results. The presence of up to about 10 pct CaF₂ in the slag makes it possible to maintain a higher slag basicity and therefore a lower activity of silica, resulting in lower silicon contents in the metal. Iron contents of up to about 20 pct in the metal cause a slight increase in the silicon content of the metal under otherwise similar conditions. The effect of 1 to 2 pct carbon in the metal on the equilibrium was roughly estimated and found to be almost negligible.