Showing papers by "Uppsala University published in 1974"
TL;DR: In this article, a statistical model is developed for the study of similarities and differences in factor structure between several groups, assuming that the observed variables satisfy a factor analysis model in each group, i.e. factor means, factor loadings, factor variances and covariances and unique variances.
Abstract: A statistical model is developed for the study of similarities and differences in factor structure between several groups. The model assumes that the observed variables satisfy a factor analysis model in each group. A method of data analysis is presented which, in contrast to earlier work, makes use of information in the observed means as well as the observed variances and covariances to estimate the parameters in each group, i.e. factor means, factor loadings, factor variances and covariances and unique variances. Usually the units of measurement in the observed variables have no intrinsic meaning and therefore it is only meaningful to compare the relative magnitudes of the parameters for the different groups. The method estimates the parameters for all groups simultaneously and can take into account a priori information about factorial invariance of various degrees.
676 citations
TL;DR: In this article, a new method for preparing adsorbents for biospecific affinity chromatography is described, and the optimal conditions for the activation and subsequent coupling of proteins, peptides and aliphatic and aromatic amines have been evaluated.
641 citations
TL;DR: In this paper, the development during the most recent years of ESCA applied to free molecules is reviewed and the advantages of studying, when possible, a substance in free molecules are discussed.
467 citations
01 Jan 1974
TL;DR: In this paper, the authors define finite element and finite difference methods for hyperbolic partial differential equations and show that the resulting procedures are automatically stable and there is extreme flexibility in choosing the basic functions, therefore, in very complicated domains or for problems with complicated interfaces, the method is the only feasible one.
Abstract: Publisher Summary
This chapter defines finite element and finite difference methods for hyperbolic partial differential equations. The advantage of the finite element method is that the resulting procedures are automatically stable and there is extreme flexibility in choosing the basic functions. Therefore, in very complicated domains or for problems with complicated interfaces, the method is the only feasible one. For hyperbolic partial differential equations it is essential to control the dispersion, dissipation, and the propagation of discontinuities. This is easily done by using suitable difference approximations. The main disadvantage of finite difference methods is that it may be difficult to handle boundaries properly.
454 citations
TL;DR: Aliphatic and aromatic alcohols in the form of glycidyl ethers have been coupled to agarose gels, which thus contain hydrophobic substituents, which have been used as adsorbents in hydrophobia interaction chromatography.
339 citations
TL;DR: The highly cationic proteins of human granulocytes, whose electrophoretic mobilities toward the cathode are faster than that for lysozyme, were isolated from the cytoplasmic granules of leukocytes, obtained from patients with chronic myeloid leukemia.
241 citations
192 citations
TL;DR: The results suggest that the L type of rat liver pyruvate kinase belongs to the enzymes whose activity is regulated by phosphorylation-dephosphorylation reactions.
172 citations
TL;DR: The line profile of the narrow, symmetric 1s line from neon, recorded with the new ESCA instrument with X-ray monochromatization, is analyzed in this paper.
167 citations
TL;DR: In this paper, ETA-dissociated polysomes from normally growing and adenovirus-infected KB cells were fractionated by affinity chromatography on oligo(dT)-cellulose into an unadsorbed fraction containing the ribosomal subunits and a second fraction which bound to the adsorbent.
155 citations
TL;DR: The presented morphological and functional characteristics closely resemble those of lymphosarcoma cells in short‐term culture and distinguish both lines from Epstein‐Barr virus‐carrying lymphoblastoid lines obtainable from normal and malignant lymphoid tissue.
Abstract: Two human cell lines, U-698 M and U-715 M, with unique characteristics were derived from two patients with lymphosarcoma. The presented morphological and functional characteristics closely resemble those of lymphosarcoma cells in short-term culture and also distinguish both lines from Epstein-Barr virus-carrying lymphoblastoid lines obtainable from normal and malignant lymphoid tissue. It is therefore proposed that the lines originate from the donors' tumor-cell population.
TL;DR: The protein tracer arrived in the perikarya prior to the earliest described response of these neurons to axonal injury, and different hypotheses involving a disturbed retrograde transport of macromolecules for eliciting chromatolysis of peripheral neurons following injury to their axons are reviewed.
TL;DR: Most students of visual velocity perception implicitly assume that constant velocity is seen as such, but this notion was challenged and shown to be inadequate in four experiments, implying the existence of a perceptual concept of velocity which includes or presupposes a natural start.
Abstract: Most students of visual velocity perception implicitly assume that constant velocity is seen as such. This notion was challenged and shown to be inadequate in four experiments. A CRT-generated bright spot moved in a linear path according to different velocity time functions. Observers compared these movements pairwise as to their perceived constancy of velocity, or drew graphs describing perceived velocity along the track. Objects moving with constant velocity appear to move fast in the beginning and suddenly slow down to a much lower velocity. There is also a qualitative difference between the start phase and the rest. To be seen as constant, a movement must start smoothly with a certain acceleration and later level off to a constant velocity (natural motion). Such movements also look slower than others with the same average velocity. The results are taken to imply the existence of a perceptual concept of velocity which includes or presupposes a natural start. Consequences for velocity scaling, acceleration thresholds, and other motion perception studies, as well as relations to eye movements and conceptual problems, are discussed.
TL;DR: Light- and electron micrographs show the strong adhesion and fusion of cell membranes and the osmotic changes in the protoplasts induced by polytehylene glycol.
TL;DR: In this article, the ESCA electron escape depth in silicon was determined from the peak areas in the electron spectra from evaporated thin films for electron energies in the region 320 eV to 3.6 keV values from 13 to 83 A.
TL;DR: The specificity of the antibody raised after immunization with oestradiol-17β-6-oxime BSA was compared with a previously used antibody obtained after conjugation in the 17th position of oest radiol- 17β to BSA, which had a higher specificity and crossreacted only 11 per cent with Oestrone compared to 50 per cent for the latter.
Abstract: SummaryAntibodies to oestradiol-17β and oestriol have been produced by immunization of sheep with oestradiol-6-oxime and oestriol-6-oxime attached to bovine serum albumin (BSA). The antibodies were used in radioimmunoassays.In the oestradiol-17β assay the free and bound steroids were separated by means of dextran-coated charcoal. This technique caused a heavy stripping when tried in the oestriol assay. A new assay for oestriol in plasma was thus devised. In this assay, oestriol and antibody were incubated at 40d`C for 30 minutes. Free and bound steroids were separated with saturated ammonium sulphate. The specificity of the antibody raised after immunization with oestradiol-17β-6-oxime BSA was compared with a previously used antibody obtained after conjugation in the 17th position of oestradiol-17β to BSA. The former antibody had a higher specificity and crossreacted only 11 per cent with oestrone compared to 50 per cent for the latter. The oestriol antibody was highly specific, crossreacting only 13 per ...
TL;DR: Studies of the primary structure have shown a high degree of homology of p2-u with the constant domains of human IgG, and suggested that /?2-/( was a free immunoglobulin domain with effector function similar to that of the C H 3 domain of IgG (Peterson et al. 1972).
Abstract: /Js-microglobulin {[^T/I) is a low molecular weight protein (MW 11.800) originally isolated by Berggard & Beam (1968) from human urine. /?2-/i was later found in human serum, cerebrospinal fluid, saliva and colostrum (Berggard & Bearn 1968, Evrin et al. 1971). The serum levels have been shown to vary within a narrow range for normal individuals (Evrin & Wibell 1972). High levels are recorded regularly in sera from patients with renal diseases (Bemier et al. 1968, Peterson et al. 1969, Wibell et al. 1973) and irregularly in patients with malignant diseases (Evrin & Wibell 1973, Kithier et al. 1974). Studies of the primary structure have shown a high degree of homology of p2-u with the constant domains of human IgG (Peterson et al. 1972, Smithies & Poulik 1972). This finding and the fact that ^2-/^ has an intrachain disulphide loop suggested that /?2-/( was a free immunoglobulin domain with effector function similar to that of the C H 3 domain of IgG (Peterson et al. 1972). Consequently early work on the production of ^2-^ by human cells was concentrated on lymphocytes. Peterson et al. (1972) and Evrin & Pertoft (1973) showed that ^2-fiwas present at the cell surface of
TL;DR: In this paper, a short review of Hermann Weyl's theory for singular second-order differential equations is given and its numerical aspects are discussed, showing that the spectral density involves approximate Lorentzians for the metastable states of the continuous spectrum corresponding to poles of $m$ in the complex plane.
Abstract: A short review of Hermann Weyl's theory for singular second-order differential equations is given and its numerical aspects are discussed. It is pointed out that this method is suitable for the treatment of perturbations which make the spectrum continuous. The Stark effect on the ground state of the hydrogen atom is taken as an example. The spectral density, the imaginary part of Weyl's "$m$ function," is calculated numerically using Runge-Kutta integration and Airy integrals for the asymptotic region. Showing $\ensuremath{\delta}$-function-like behavior with poles of $m$ on the real axis for the discrete levels, the spectral density involves approximate Lorentzians for the metastable states of the continuous spectrum, corresponding to poles of $m$ in the complex plane. Trajectories of these poles for electric fields up to 0.25 a.u. are shown for the one-dimensional as well as for the full three-dimensional problem.
TL;DR: A new series of chemical crosslinking reagents of varying bridge length which contain vicinal hydroxyl groups are described which can be quantitatively cleaved by mild treatment with periodate and can facilitate analysis of the complexes formed.
TL;DR: It is concluded that islet NAD(+) depletion is probably important for the B-cytotoxin action of N-nitrosomethylurea and streptozotocin.
Abstract: The effects on the pancreatic B cell of streptozotocin and its aglucone derivative N-nitrosomethylurea were investigated in obese–hyperglycaemic mice and their lean littermates. Both streptozotocin and N-nitrosomethylurea were found to be B-cytotoxic although N-nitrosomethylurea produced less islet damage. Both substances decreased the concentrations of NAD+ in the islet cells to about 10% of the control values within 2h after injection. This NAD+ depletion was prevented by injection of nicotinamide 10min after the administration of streptozotocin or N-nitrosomethylurea. In islets taken from animals 10min after injection of streptozotocin or N-nitrosomethylurea there was no stimulatory effect of glucose on the respiration or insulin release and the oxidation of glucose was markedly decreased. Addition of nicotinamide (10mm) to the incubated islets restored glucose stimulation of both the oxygen consumption and insulin release. It is concluded that islet NAD+ depletion is probably important for the B-cytotoxin action of N-nitrosomethylurea and streptozotocin. The glucose residue in the streptozotocin molecule may potentiate the B-cytotoxic action of this drug in mice.
TL;DR: Previous studies on the biosynthesis of heparin in a cell-free system have shown that l-iduronic acid residues are formed by C-5 epimerization of d-glucuronic Acid units at the polymer level; the process requires concomitant sulphation of the polymer.
Abstract: 1. A method was developed for determination of the uronic acid composition of heparin-like glycosaminoglycans. Polymers or oligosaccharides are degraded to monosaccharides by a combination of acid hydrolysis and deamination with HNO2. The resulting uronic acid monosaccharides (accounting for about 70% of the uronic acid contents of the starting materials) are isolated and converted into the corresponding aldono-1,4-lactones, which are separated by g.l.c. The calculated ratios of glucuronic acid/iduronic acid are reproducible within 5%. 2. Samples of heparin from pig intestinal mucosa (molar ratio of sulphate/disaccharide unit, 2.40) and heparan sulphate from human aorta (sulphate/disaccharide ratio, 0.46) were subjected to uronic acid analysis. l-Iduronic acid constituted 77% and 19% respectively of the total uronic acid contents. 3. The correlation between the contents of sulphate and iduronic acid indicated by this finding also applied to the fractionated deamination products of the two polymers. The sulphated fragments varied in size from disaccharide to octasaccharide (or larger) and showed sulphate/disaccharide molar ratios in the range of 0.05–2.0. The proportion of iduronic acid increased with increasing ester sulphate contents of the oligosaccharides. 4. Previous studies on the biosynthesis of heparin in a cell-free system have shown that l-iduronic acid residues are formed by C-5 epimerization of d-glucuronic acid units at the polymer level; the process requires concomitant sulphation of the polymer. The results obtained in the present structural study conform to these findings, and suggest further that similar mechanisms may operate in the biosynthesis of heparan sulphate. The epimerization reaction appears to be linked to the sulphation of hydroxyl groups but does not seem to require sulphation of the target uronic acid residues. The significance of sulphamino groups in relation to the formation of iduronic acid is unknown.
TL;DR: Bromophenols were detected in species from the families Ceramiaceae, Delesseriaceae, Bonnemaisoniaceae, Rhodophyllaceae, Corallinaceae and Rhodomelaceae, and lanosol was identified in sea water from the Polysiphonia Brodiaei —zone.
TL;DR: The biological half-life of RBP was increased by about 50% in protein deficiency while the rate of synthesis was diminished to one-third of the normal value, and the labeled RBP component exhibited a slower electrophoretic mobility than genuine RBP, which could complex with prealbumin.
Abstract: Publisher Summary This chapter presents different aspects of the metabolism of retinol-binding protein (RBP) and retinol. RBP is not significantly decreased until the liver reserves of the vitamin are virtually abolished. The diminished concentration of RBP in plasma in manifest vitamin A deficiency reflects the impaired transport of retinol to the various tissues. The catabolism of RBP is probably greatly dependent on renal function, since a small fraction of free RBP exists in plasma although most is bound to prealbumin. The biological half-life of RBP was increased by about 50% in protein deficiency while the rate of synthesis was diminished to one-third of the normal value. The cellular accumulation of retinol is a temperature-dependent process. Incubations of the cells in the absence of oxygen or in the presence of metabolic inhibitors like sodium azide and EDTA did not change their ability to extract retinol from RBP. It is seen that the labeled RBP component exhibited a slower electrophoretic mobility than genuine RBP, which could complex with prealbumin. The low pH was chosen to minimize charge differences due to variable content of amide groups in the two forms of RBP.
TL;DR: A brief review of the technique of applying ESCA to liquid samples is given in this article, where a list of solvents suitable for ESCA studies is presented and the particul
TL;DR: In this article, the authors consider difference methods for the solution of singular perturbations of boundary value problems and show that only approximations of low order accuracy can be used.
Abstract: We consider difference methods for the solution of singular perturbations of boundary value problems. The solutions are smooth except in boundary layers of thickness ?|log?|, 0
TL;DR: A chemically defined medium has been developed for isolation of amino acid-requiring mutants of Staphylococcus aureus strain 8325, and for use as a selective medium in transformation assays.
Abstract: A chemically defined medium has been developed for isolation of amino acid-requiring mutants of Staphylococcus aureus strain 8325, and for use as a selective medium in transformation assays. Variables affecting transformation of both plasmid and chromosomal markers have been studied. The optimal pH and temperature for transformation are 6.75 to 7.0 and 30 C, respectively. Ca ions are required for transformation, and only cells lysogenic for the phage φ11 can be transformed. Superinfection of competent cells with φ11 does not increase the transformation frequency. Maximal number of transformants is obtained after 20 min of contact between cells and deoxyribonucleic acid. The transformation frequencies for the plasmid marker erythromycin resistance (ero) and the chromosomal markers trp, thy, and cyt are of the same order of magnitude, whereas the frequency for the chromosomal marker tyr is approximately one order of magnitude lower.
TL;DR: P pig liver pyruvate kinase (type L) was 32 P-labelled by incubation with ( 32 P)ATP and cyclic 3′,5′-AMP-stimulated protein kinase from the same source.
01 Jan 1974
TL;DR: The physical conditions for producing minute disc-shaped lesions for functional radiation surgery by means of narrow beam irradiation by means for routine clinical use and with high physical and mechanical reproducibility are discussed.
Abstract: The physical conditions for producing minute disc-shaped lesions for functional radiation surgery by means of narrow beam irradiation are discussed. The intention was a treatment procedure for routine clinical use and with high physical and mechanical reproducibility. The possibilities of using high energy electrons, supervoltage roentgen radiation, gamma emitting nuclides or fast neutrons in a technique for routine clinical use were investigated. The radiation of choice taking physical properties, radiation biologic factors and practical circumstances into account was considered to be 60-Co gamma radiation. A treatment apparatus containing 179 60-Co sources within a spherical sector of 70 degrees latitude and 160 degrees longitude was constructed.
TL;DR: There was an inverse relationship between protein A content of strains and the quantity of bacteriophage absorbed, and no inhibition of staphylococcal phages was obtained with purified soluble protein A.
Abstract: Experiments were performed to determine if protein A influenced the association of bacteriophages with Staphylococcus aureus. Bacteriophage adsorption was compared in a S. aureus strain rich in protein A and mutants of this strain with very little protein A, in a strain with little protein A, and in mutants of this strain with increased protein A. In addition, the effect of growth in mannitol-salt broth and trypsin digestion (known to reduce protein A) on bacteriophage absorption was measured. There was an inverse relationship between protein A content of strains and the quantity of bacteriophage absorbed. However, no inhibition of staphylococcal phages was obtained with purified soluble protein A. Protein A as a surface component rendered the bacteria more resistant to adsorption of staphylococcal typing phages presumably by masking the phage receptor sites. When protein A-deficient mutants were incubated with bacteriophages, there was survival of staphylococci with increased protein A content probably due to a selective action.
TL;DR: In this paper, two pianists and one percussionist performed a number of notated rhythms on the piano and on the side drum or the bongo drum, and the tape-recordings of the performances were analyzed by an analyzer for mono-phonic sound sequences as regards the durations and the amplitudes.
Abstract: .— Two pianists and one percussionist performed a number of notated rhythms on the piano and on the side drum or the bongo drum. The tape-recordings of the performances were analyzed by an analyzer for mono-phonic sound sequences as regards the durations and the amplitudes. Several characteristic deviations from the norms implied by the musical notation appeared. The recordings were used as stimuli in experiments on rhythm experience described elsewhere.