Downregulation of cytokine-induced neutrophil chemoattractant and prolongation of rat liver allograft survival by interleukin-10

Deficiency of the complement protein C2 (C2D), one of the most common genetic deficiencies of the complement system, is associated with rheumatological disorders and increased susceptibility to infection. Two types of C2D have been recognized, each in the context of specific major histocompatibility complex (MHC) haplotypes; type I, a deletion, frameshift and premature stop codon resulting in absence of detectable C2 protein synthesis, and type II, missense mutations resulting in a block in secretion of C2 proteins. Analysis of C2 expression in a child with C2 deficiency, a MHC haplotype different from those associated with type I or II C2D, and recurrent infections revealed additional molecular heterogeneity among C2 deficient patients. No detectable C2 protein was synthesized in the child's fibroblasts under conditions supporting C2 synthesis and secretion in normals and the child's C2 mRNA was reduced to 42% of normal. Nucleotide sequencing of RT-PCR fibroblast mRNA and genomic DNA revealed a type I C2 deficiency (28 base-pair deletion) on one allele and a previously unrecognized two base-pair deletion in exon 2 on the other. Expression of the closely linked factor B gene was markedly decreased (Bf mRNA 25% of normal), though Bf was up-regulated appropriately by interferon-gamma and the flanking sequence containing the Bf promoter was normal in this C2-deficient patient. Moreover, the concentration of Bf protein was normal in the patient's plasma.     

Evolution of nonlinear dissipative systems with application to a macro-economic organism

A method of describing an evolutionary process of a macro-economic system is presented, in which it is noted that the system consists of both material and monetary flows. The macro-economic organism as a dissipative system evolves toward a goal at which the irreversible decay rate of the system is minimized. The present irreversible decay rate is found to be the ratio of the material dissipation rate per unit time to the total material production rate. The fact that a macro-economic system with smaller irreversible decay rate is more stable during time development implies that the system with more capital accumulation is more stable. An experiment confirming the result is also presented.     

Quantitative analysis of the action of Taka-amylase A on maltotriose

The action of Taka-amylase A from Asp. oryzae was studied quantitatively by the product analysis method using unlabeled maltotriose and maltotriose labeled at the reducing end as substrates. It was found that the ratio of the unlabeled products, maltose (G2) and glucose (G1) exceeded unity, and that the ratio of the labeled products, G2/G1 was strongly dependent on the initial substrate concentrations. The results can only be explained by a transglycosylation or condensation mechanism or both. Analysis of maltose labeled at the nonreducing or reducing end reveal that the ratio of the transglycosylation to the condensation mechanism was about 20:1 with about 80 mM maltotriose. A computer simulation was made on a reaction scheme involving the termolecular-shifted complex, transglycosylation and condensation besides hydrolysis, by using reported subsite affinities as modified by the authors. The simulation reproduced the experimental results satisfactorily.     

Difficulty of singularity in population coding

Fisher information has been used to analyze the accuracy of neural population coding. This works well when the Fisher information does not degenerate, but when two stimuli are presented to a population of neurons, a singular structure emerges by their mutual interactions. In this case, the Fisher information matrix degenerates, and the regularity condition ensuring the Cramér-Rao paradigm of statistics is violated. An animal shows pathological behavior in such a situation. We present a novel method of statistical analysis to understand information in population coding in which algebraic singularity plays a major role. The method elucidates the nature of the pathological case by calculating the Fisher information. We then suggest that synchronous firing can resolve singularity and show a method of analyzing the binding problem in terms of the Fisher information. Our method integrates a variety of disciplines in population coding, such as nonregular statistics, Bayesian statistics, singularity in algebraic geometry, and synchronous firing, under the theme of Fisher information.     

Analysis of phenmedipham in agricultural products by HPLC

An analytical method was developed for the determination of phenmedipham (PM) in agricultural products using reversed-phase high-performance liquid chromatography with UV detection. A sample was extracted with acetonitrile, and the acetonitrile layer was separated by salting-out. The acetonitrile phase was isolated and evaporated. The extract was dissolved in diethyl ether-hexane (1 : 1), and then cleaned up on a Florisil column. The column was washed with diethyl ether-hexane (1 : 1), and PM was eluted with acetone-hexane (3 : 7), and the eluate was evaporated. The residue was dissolved in acetone-hexane (2 : 8), and the sample solution was cleaned up on SAX/PSA cartridge. The SAX/PSA cartridge was washed with acetone-hexane (2 : 8), and PM was eluted with acetone-hexane (3 : 7). If required, the eluate of the Florisil column was cleaned up with SAX/PSA and ENVI-Carb/ NH2 cartridges. The SAX/PSA cartridge was washed with acetone-hexane (2 : 8), and connected to be ENVI-Carb/NH2 cartridge. The cartridges were washed with acetone-hexane (3 : 7), and then the SAX/PSA cartridge was removed. PM was eluted with acetonitrile-toluene (3 : 1) from the ENVI-Carb/NH2 cartridge. PM in the eluate was separated isocratically on an ODS column (4.6 mm i.d. x 150 mm, 5 microm) using acetonitrile-water (6 : 4) as a mobile phase (flow-rate 1.0 mL/min, temp. 40 degrees C), with monitoring at 235 nm. The calibration curve was linear from 0.005 microg/mL to 10 microg/mL of PM. The recoveries of PM from eight kinds of agricultural products spiked at levels of 0.1 and 0.02 microg/g were 80.8-98.7%. The determination limit was 0.01 microg/g.     

Isolation and characterization of a parvovirus of rabbits

The isolation and characterization of a new virus from rabbit stool are described. The virus replicated in rabbit kidney cell cultures and agglutinated human group O erythrocytes at 4 degrees C. It was stable at acid pH and resistant to chloroform and heat treatment. The growth of the virus was inhibited by 5-iodo-2-deoxyuridine, and virions were stained red with acridine orange, suggesting that they contain single-stranded deoxyribonucleic acid. The density of virions was 1.41 to 1.44 g/ml in CsCl, and the sedimentation value was 137S in sucrose at 4 degrees C. The infectious particles had cubic symmetry and were 27 to 28 nm in diameter by electron microscopy. By these properties this virus can be classified as a member of the parvovirus group. Antibody response was demonstrated in the rabbit from which this virus was recovered. A number of rabbits from a commercial source were found to contain hemagglutination-inhibiting antibody to this virus.     

Migration of suspended particles in plane stationary ultrasonic field

The time-averaged motion of microscopic particles in plane stationary sound fields is investigated. A generalized kinetic theory of particle migration in which the effect of particle diltusion is taken into account is formulated and the particle distributions at the rather early stage and after a sufficient sound irradiation are derived analytically from the theory. It is found that the nodal change of particle concentration of microscopic polystyrene latex dispersions is well predicted by the present theory, independently of the particle size, the sound frequency and the energy density of sound. The condition of formation of the Kundt's tube striation is also characterized theoretically.     

Detection of parafoveal scotoma by multifocal electroretinograms

We investigated the relation between multifocal electroretinograms (M-ERGs) and artificial parafoveal scotoma. M-ERGs were recorded from normal subjects using a circular piece of black paper attached to a monitor. Lower response density around the 10 to 15 degree parafovea region was not observed up to 3 degree scotoma (visual angle), but was detected above 5 degree scotoma in field topography of M-ERGs. The shape of the scotoma in field topography was not circular but somewhat oval. The results from two cases of parafoveal retinal degeneration were in good accordance with this basic study in normal subjects. We proved that detection of parafoveal scotoma by M-ERG is limited in comparison with the results obtained by automated static perimetry.