Use of exercise technetium-99m sestamibi SPECT imaging to detect residual ischemia and for risk stratification after acute myocardial infarction

The clinical presentation, electrocardiographic findings, and technetium-99m sestamibi single-photon emission computed tomography (SPECT) imaging results of 134 consecutive patients who underwent nuclear exercise testing within 14 days of an acute myocardial infarction (AMI) were correlated with cardiac events over a 15 +/- 10-month follow-up. Whereas only 23 patients (17%) had chest pain and 31 (23%) had ischemic ST-segment depression during exercise, 94 (70%) had ischemia on SPECT (p < 0.001). On follow-up, 13 patients experienced a cardiac event: 7 were rehospitalized for unstable angina, 3 had recurrent AMI, and 3 died of cardiac causes. Ischemia on the sestamibi images identified 11 of these patients (85%), whereas chest pain identified only 3 (23%, p = 0.006), and electrocardiographic ischemia identified only 4 (31%, p = 0.017). The presence of either ischemia as seen on SPECT or defects in multiple vascular territories identified 12 patients (92%) with an event, including all who had cardiac death. By Cox regression analysis of clinical, stress, and image parameters, the number of ischemic defects on SPECT was the only significant correlate of a future event (chi-square = 4.62, p = 0.03), and patients with > or = 3 reversible sestamibi defects had an event rate of 38%. The extent of ischemia as seen on nuclear imaging remained a strong correlate (p = 0.008) of an event in the 54 patients (40%) who had received thrombolytic therapy. Thus, exercise technetium-99m sestamibi SPECT after AMI frequently reveals residual ischemia, and is better than clinical data, symptoms, and stress electrocardiographic data in identifying patients who will have a subsequent cardiac event.     

Disability among the population of the Russian Federation

Previously we demonstrated that in the course of intracellular reproduction of WSN influenza virus strain, part of monomeric nucleoprotein (NP) undergo polymerization into dimers and trimers, which dissociate into monomers after boiling. Further studies showed that different strains of influenza virus are characterized by different degree of NP-oligomerization. Specifically, Duck/ Ukraine/63 (H3N8) and Seal Massacuhsets 1/80 (H7N7) NP monomers are completely transformed into oligomers. As a result of 40-min chase and of prolonged label exposure only NP-oligomers but not monomers can be detected in unboiled samples of infected cells or in virions. NP monomers of A/Duck/Ukraine strain are detectable in unboiled samples only after a short period of labeling. Influenza virus NP oligomers are more hydrophobic than NP monomers. Oligomers are hypothesized to be the native functionally important form of influenza virus NP.     

Computer modeling of the neural network recognizing the contrasts on the image

Computer modeling of the neuron network offered in [1] is discussed. Organization and feature of modeling are described, as well as the changes, which are introduced in the network during researches. Results of modeling are present.     

Diagnostic value of the reaction of morphological dissociation of clotted blood (RMDCB) in nonspecific pneumonias and lung cancer

The authors studied separate parameters of the reaction of morphological dissociation of clotted blood in 97 patients, 83 of them suffering chronic nonspecific pneumonia and 14--lung cancer. Such RMDCB tests as the amount of the third fraction of blood coagulation (TFCB), the time of TFCB sediment formation and "the prognostic index" are found to be of certain diagnostic value, and along with other laboratory tests and clinical symptoms these allowed a differentiation between chronic nonspecific pneumonia and lung cancer.     

Tau self-association: stabilization with a chemical cross-linker and modulation by phosphorylation and oxidation state

tau is a major component of paired helical filaments found in the neurofibrillary tangles of Alzheimer's diseased brain. However, the mechanism or mechanisms responsible for the association of tau to form these aggregates remains unknown. In this study, the role of intermolecular disulfide bonds in the formation of higher order oligomers of bovine tau and the human recombinant tau isoform T3 was examined using the chemical cross-linking agent disuccinimidylsuberate (DSS). In addition, the role of phosphorylation and oxidation state on the in vitro self-association of tau was studied using this experimental model. Stabilization of tau-tau interactions with DSS indicated that intermolecular disulfide bonds probably play a predominant role in dimer formation, but the formation of higher order oligomers of tau cannot be attributed to these bonds alone. tau-tau interactions were significantly decreased either by blocking Cys residues or by exposing the tau to a reducing (nitrogen and dithiothreitol), instead of an oxidizing, environment. tau self-association was also significantly decreased by prior phosphorylation with calcium/calmodulin-dependent protein kinase II. Phosphorylation by cyclic AMP-dependent protein kinase or dephosphorylation by alkaline phosphatase did not alter tau self-assembly. These data suggest a role for several factors that may modulate tau self-association in vivo.     

Problems of computer modelling and information facilities for diffusion bonding

The methods for improving arc striking with wires of minor diameter and for ensuring the weld formation at a current of 10 A with minimum melting and spatter losses are considered.     

Influence of rock-forming and catalytic additives on transformation of highly viscous heavy oil

The influence of the rock-forming additives kaolin and alumina in the presence of nickel compounds on the thermal catalytic conversion of heavy oil at a temperature of 360°C in a reducing atmosphere at different pressures in the system has been revealed. The effect of poly-α-olefins as a hydrogen donor has been examined. It has been found that there are predominant degradation reactions of the resinous components, aliphatic substituents in asphaltenes, and branched aliphatic structures accompanied by redistribution of n-alkanes toward homologues with a lower molecular weight, resulting in reduction in the viscosity of heavy oil. Conducting the process in the presence of Al₂O₃, Ni, and poly-α-olefins at a pressure of 8 MPa increases the quantity of light fractions of the oil and facilitates the degradation of asphaltenes. A decrease of pressure in the experiment on the oil with kaolin in a reducing atmosphere leads to a decrease in aromaticity of the final product and an increase in the yield of lube oil hydrocarbon and low-boiling fractions.