Showing papers by "Linköping University published in 1976"
TL;DR: The IgE levels were found to be lower than in previous investigations, and this was attributed to the refined technique and the method of selection.
Abstract: Summary
Serum IgE was estimated in 226 healthy children aged 0–14 years without obvious atopic disease in their first degree relatives. A paper disc radioimmunoassay technique (PRIST) was used. A number of criteria for selection of cases were established. This led to the exclusion of forty-two potentially atopic children. The remaining group of 184 children is considered representative of normal children and may therefore be used for reference purposes. The IgE levels were found to be lower than in previous investigations, and this is attributed to the refined technique and the method of selection.
309 citations
TL;DR: Determination of serum IgE with the PRIST‐technique has been shown to provide a valuable means for predicting future atopic manifestations and may be used as a screening procedure especially in children of atopic parents.
Abstract: A group of 207 healthy non-atopic children 0-14 years of age without any known family history of atopic disease was selected for a study of the relation between serum IgE levels and the occurrence of atopic manifestations during an observation period of 18 months; 206 fullfilled the study. Serum IgE was measured by a direct radioimmunological sandwich technique (PRIST). At the follow-up 28 of 32 with an initial IgE level greater than one standard deviation above the mean for the age continued to show a high level (87.5%). The total concordance was 81.1%. Atopic or probable atopic diseases had developed in 75.0% of children 0-1 year of age with an initial IgE above +1 S.D., but in only 6.4% of those from the same age group with a lower initial IgE. Even among children 2-14 years old, it was noticement of atopic disease. Otitis media was more frequent among children with an initially elevated IgE level than among the rest of the children. Determination of serum IgE with the PRIST-technique has been shown to provide a valuable means for predicting future atopic manifestations and may be used as a screening procedure especially in children of atopic parents.
148 citations
TL;DR: In this paper, the convergence and consistency of the least square estimation of the parameters of a vector difference equation model of a dynamic system is studied. And a theorem for the convergence of the estimation is given that is valid under general feedback conditions.
Abstract: Least-squares estimation of the parameters of a vector difference equation model of a dynamic system is studied. A theorem for the convergence and consistency of the least-squares estimate is given that is valid under general feedback conditions.
129 citations
TL;DR: Programs which perform partial evaluation, beta-expansion, and certain optimizations on programs, are studied with respect to implementation and application.
112 citations
TL;DR: The observations indicate that the immune response is most vigorous in disabled patients with a short duration or with an early age at onset of the disease, irrespective of the occurrence of disability.
109 citations
TL;DR: The possibility of estimating the parameters of a dynamic system when it is operating in closed loop is examined and a simple criterion is given, which contains earlier known conditions as simple special cases.
Abstract: The possibility of estimating the parameters of a dynamic system when it is operating in closed loop is examined. Earlier considered ways of designing regulators to achieve desired identifiability properties are unified and generalized. The result of the analysis of this short paper gives a simple criterion, which contains earlier known conditions as simple special cases.
101 citations
TL;DR: It is concluded that the serum IgE in newborns seems to be of foetal origin and that the determination of serum Ig E in infants is of value in predicting atopic allergy.
Abstract: Serum IgE levels were studied in 2 groups of children with a family history of atopic disease, 30 in whom the mother only and 38 in whom both parents had atopic disease. IgE antibodies were determined with Phadebas RAST Test and serum IgE with Phadebas IgE Test and Phadebas PRIST at 0, 3, 9, 12 and 18 months of age. There was no correlation between the serum IgE levels in mothers and their newborns. RAST tests were frequently positive in maternal sera but no positive RAST test was found in the newborns. Obvious and probable atopic disease developed during the observation period in 42.1% of the children with a double family history of atopic disease. In 75% of these the serum IgE level was above the upper limit of normal on an average 6 months before the onset of atopic symptoms. An elevated IgE level without atopic symptoms during the observation period occurred in only one child. It is concluded that the serum IgE in newborns seems to be of foetal origin and that the determination of serum IgE in infants is of value in predicting atopic allergy.
99 citations
TL;DR: The noise levels in the cochlea when a drill is used in the mastoid process have been calculated from vibration measurements on intact skulls of human cadavers and temporal bones to lend support to the conclusion that, in ear surgery, the ipsilateral coChlea is exposed to noise levels of about 100 dB and the contralateral co chlea to levels 5-10 dB lower every time the drill is using.
Abstract: The noise levels in the cochlea when a drill is used in the mastoid process have been calculated from vibration measurements on intact skulls of human ca- davers and temporal bones. The results lend support to the conclusion that, in ear surgery, the ipsilateral cochlea is exposed to noise levels of about 100 dB and the contra- lateral cochlea to levels 5-10 dB lower every time the drill is used. This noise trauma may account for some of the high-tone sensorineural hearing losses after tyrnpano- plasty described by other authors.
91 citations
TL;DR: Results obtained by a direct sandwich and three inhibition methods of radioimmunoassays are compared and for values above 50 U/ml good correlation was obtained with all methods.
Abstract: Accurate measurement of low IgE concentrations if technically difficult. In this paper results obtained by a direct sandwich and three inhibition methods of radioimmunoassays are compared. For values above 50 U/ml good correlation was obtained with all methods. Below 50 U/ml, however, the inhibition methods tended to yield falsely high values. For very low concentrations, 1--10 U/ml the best correlation was obtained between the direct sandwich test (PRIST) and the inhibition test using a correction factor to allow for the non-specific effect of serum. The four methods were used to quantify IgE in cord serum samples from healthy individuals. The mean value obtained by PRIST was 0-4 U/ml and by the inhibition test, using a correction factor, 0-6 U/ml respectively. Because of its greater simplicity the direct sandwich test is recommended.
81 citations
01 Jan 1976
TL;DR: This chapter discusses the methods for sparse linear least squares problems, which generally arise in the same contexts as sparse linear equations and include geodesy, photogrammetry, statistical computations, and structural analysis.
Abstract: Publisher Summary This chapter discusses the methods for sparse linear least squares problems. It reviews direct and iterative methods for solving sparse least squares problems. These problems generally arise in the same contexts as sparse linear equations. Among the applications are geodesy, photogrammetry, statistical computations, and structural analysis. As the subject is rapidly developing and so far not enough is known about the algorithms, it has generally not been possible to make final assertions about the relative efficiency of different algorithms. Direct methods have the general advantages over iterative methods that subsequent right hand sides can be treated efficiently and it is easier to obtain elements of related inverse matrices. With direct methods, it is also possible to use the technique of iterative refinement. The most straightforward method to solve the least squares problem is to form the normal equations and then compute the Cholesky factorization. For dense problems, iterative refinement is a cheap and simple way to improve the accuracy of a computed solution. It also has the advantage that it gives useful information about the condition of the problem.
53 citations
TL;DR: In this article, a positive measurable function f on Rd can be symmetrized to a function f* depending only on the distance r, and with the same distribution function as f. This inequality is a generalisation of the classical isoperimetric inequality for sets.
Abstract: A positive measurable function f on Rd can be symmetrized to a function f* depending only on the distance r, and with the same distribution function as f. If the distribution derivatives of f are Radon measures then we have the inequality ∥∇f*∥≤∥∇f∥, where ∥∇f∥ is the total mass of the gradient. This inequality is a generalisation of the classical isoperimetric inequality for sets. Furthermore, and this is important for applications, if f belongs to the Sobolev space H1,P then f* belongs to H1,P and ∥∇f*∥p≤∥∇f∥p.
TL;DR: Two groups were selected: children with a history of recurrent otitis media and/or otosalpingitis (middle ear effusion) and those in which nasal obstruction was the main symptom, and no significant difference was found between the two groups.
Abstract: From 274 adenoidectomized children 1-16 years of age two groups were selected: children with a history of recurrent otitis media and/or otosalpingitis (middle ear effusion) and those in which nasal obstruction was the main symptom. In all, 154 children were subjected to an allergy investigation including history, skin tests, eye tests, determination of IgE and RAST, blood eosinophils and immunoglobulins G, A and M. No increased incidence of immunoglobulin deficiency was found in either group in comparison with unselected children. A family history of atopic disease and/or otitis media was highly overrepresented, especially in the children with recurrent otitis media as the reason for the adenoidectomy. Atopic diseases had occurred in 24.4% of the children. Furthermore, in both groups there was a high incidence of positive skin and eye tests. An increased incidence of eosinophila, positive RAST tests and elevated IgE levels were also found. In all, 39.6% of the children had two or more laboratory findings characteristic of the atopic state but no significant difference was found between the two groups. Possible connections between atopic allergy and recurrent otitis media are discussed.
TL;DR: In this paper, a general method for analysis of elasto-plastic beams and frames with large displacements is described, based on inversion of a flexibility matrix, which is computed from an assumed distribution of internal forces along the element axis.
TL;DR: Slow evoked cortical potentials from ten young normal-hearing subjects have been recorded as responses to linear frequency ramps of a continuous pure tone and a functional model is proposed in which the time derivate of the signal frequency is integrated with an adaptable integration time that is controlled by the rate of the frequency change.
Abstract: Slow evoked cortical potentials from ten young normal-hearing subjects have been recorded as responses to linear frequency ramps of a continuous pure tone. Frequency changes from 10 to 500 Hz were studied; the rate of frequency change was varied from 0.02 to 50 kHz/s while the duration of the change was varied from 10 to 500 ms. The rate of frequency change was shown to have the greatest bearing on the responses except for frequency ramp durations below 50 ms and frequency changes below 50 Hz. The base frequencies (250-4000 Hz) and sound levels (20-80 dB HL) exerted an influence on the evoked responses that was qualitatively similar to their influence on behavioral thresholds. The direction of the frequency sweep had no significant influence on the evoked responses. A functional model is proposed in which the time derivate of the signal frequency is integrated with an adaptable integration time that is controlled by the rate of the frequency change.
TL;DR: In this article, the density of expanded crystalline Hg was calculated for the fcc, bcc, and sc structures in the density range ∼ 4-9 g/cm3.
TL;DR: In this article, the APW structure of the Ti 3 d and C 2 p bands was predicted to be a strong hybridization with a C 2 s band at lower energy.
01 Dec 1976
TL;DR: In this article, the asymptotic normality of a large class of prediction error estimators is established, and it is shown that the prediction error method using the determinant of the residual error covariance matrix as loss function is efficient with respect to the specified class of estimators regardless of the distribution of the observed processes.
Abstract: In this paper the asymptotic normality of a large class of prediction error estimators is established (Prediction error identification methods were introduced in [1] and further developed in [2] and [3]) The observed processes in this paper are assumed to be stationary and ergodic and the parameterized process models are taken to be non-linear regression models In the gaussian case the results presented in this paper constitute substantial generalizations of previous results concerning the asymptotic normality of maximum likelihood estimators for (i) processes of independent random variables [9,4] and (ii) Markov processes [5]; these results also generalize previous results on the asymptotic normality of least squares estimators for autoregressive moving average processes [6,7] The asymptotic normality theorem gives formulae for the covariances of the asymptotic distributions of the parameter estimation errors arising from the specified class of prediction error identification methods Employing these formulae it is demonstrated that the prediction error method using the determinant of the residual error covariance matrix as loss function is asymptotically efficient with respect to the specified class of prediction error estimators regardless of the distribution of the observed processes
TL;DR: The influence of variations of oxygen tension on the metabolism of bovine mesenteric arteries was studied in vitro and a marked Pasteur effect was observed.
TL;DR: In this article, photoelectron spectroscopy was used to study aluminum and magnesium using He I (21.2 eV) and He II (40.8 eV), and no sign of any structure due to plasma losses can be seen in the spectra.
TL;DR: In this article, a detailed K-LL Auger spectra of aluminium metal obtained either by X-ray excitation or electron bombardment is presented, which are rich in plasmon peaks.
Abstract: Detailed K-LL Auger spectra of aluminium metal obtained either by X-ray excitation or electron bombardment are presented. Both spectra, which are rich in plasmon peaks, are very similar. The experimental energies are in close agreement with calculations in which two-hole coupling and relaxation effects are taken into account.
TL;DR: The examination technique has been tested on 15 young, healthy subjects with no clinical signs or symptoms in their knee joints and to test the accuracy of the method, seven of the subjects were re-examined at a later date.
Abstract: An orthoradiographic method for preoperative assessment of mediolateral instability and varus/valgus deviation in gonarthorsis is presented. A special definition of the varus/valgus deviation is given. The examination technique has been tested on 15 young, healthy subjects with no clinical signs or symptoms in their knee joints. To test the accuracy of the method, seven of the subjects were re-examined at a later date.
TL;DR: Three patients treated daily with vitamin A acid cream experienced after one week, seven weeks and 14 weeks respectively sudden redness and itching at the treated sites, and it is probable that these latter reactions were due to contact allergy.
Abstract: Three patients treated daily with vitamin A acid cream experienced after one week, seven weeks and 14 weeks respectively sudden redness and itching at the treated sites. Patch testing with the cream (containing 0.05% vitamin A acid) and with vitamin A acid 0.05% in absolute alcohol produced strongly positive reactions in the patients but only slight erythema in some of the controls. Since patch testing with vitamin A acid 0.005% in absolute alcohol elicited no response in controls but positive reactions in the three patients, it is probable that these latter reactions were due to contact allergy. Histologically the test reaction showed intact epidermis and dense dermal infiltration by mononuclear cells, and thus resembled a response of the tuberculin type.
TL;DR: The present data indicate that the finding of oligoclonal CSF IgG may increase the risk of developing multiple sclerosis.
TL;DR: Of the two drugs phenytoin seemed to have the most marked myocardial depressant effect, thus giving plasma concentrations within the suggested therapeutic ranges.
Abstract: The haemodynamic effects of procainamide and phenytoin after intravenous administration to 19 patients with suspected congenital heart lesions were studied. The drugs were injected into the pulmonary artery in a dose of 5 mg per kg body-weight, at an infusion rate of 50 mg per minute, thus giving plasma concentrations within the suggested therapeutic ranges. The diastolic pressures in the pulmonary artery and the right ventricle were reduced by procainamide and the converse effect was noted after phenytoin. The heart rate was significantly increased by both drugs but with phenytoin this effect was only transitory. The latter drug also caused a small and transient fall in cardiac output and mean arterial pressure. It was concluded that of the two drugs phenytoin seemed to have the most marked myocardial depressant effect.
TL;DR: Results are interpreted as indicating that phosphalipase is present in lysosomes of the human gallbladder epithelium, and release of acid hydrolases, particularly phospholipase A, is discussed as mediation of an inflammatory reaction in the gallbladders, i.e. cholecystitis.
Abstract: Human gallbladder epithelium was homogenized with a view to maintaining the integrity of subcellular components. In such homogenates, N-acetyl-beta-glucosaminidase, beta-glucuronidase, beta-galactosidase, beta-glucosidase, beta-fucosidase, beta-xylosidase, and acid phosphatase were demonstrated together with phospholipase activity. All the enzymes exhibited structure-linked latency. After discarding cellular debris from the homogenate, remaining subcellular organelles were analytically separated by density gradient centrifugation. After 100,000 g for 1 hour, particles containing acid glycosidases were recovered at a sucrose density of 1.18-1.19, whereas the mitochondrial marker enzyme succinate-reductase accumulated at a density of 1.16. The bulk of sedimentable phospholipase activity was recovered with particles sedimenting at 1.18-1.19. The results are interpreted as indicating that phosphalipase is present in lysosomes of the human gallbladder epithelium. Release of acid hydrolases, in lysosomes of the human gallbladder epithelium. Release of acid hydrolases, in lysosomes of the human gallbladder epithelium. Release of acid hydrolases, particularly phospholipase A, from the gallbladder epithelium is discussed as mediation of an inflammatory reaction in the gallbladder, i.e. cholecystitis.
TL;DR: Both atenolol and propranolol caused statistically significant reduction of recumbent and erect blood pressure and heart rate in patients with essential hypertension.
Abstract: Propranolol was given to 30 patients with essential hypertension following randomised, double-blind administration of either placebo or a new cardioselective beta-adrenergic receptor antagonist, atenolol (Tenormin®, ICI 66 082). Both atenolol and propranolol caused statistically significant reduction of recumbent and erect blood pressure and heart rate. There were no important differences between these variables on comparison of atenolol and propranolol.
TL;DR: Three groups of patients receiving methoxyflurane or halothane or pethidine after thiopentone suxamethonium induction were compared and significant differences in the test battery of uric acid, creatinine, blood urea nitrogen and sodium in the methoxyFlurane series compared with the other series was found, indicating transient impaired kidney function.
Abstract: Three groups of patients receiving methoxyflurane or halothane or pethidine after thiopentone suxamethonium induction were compared. Using multivariate Student t tests with simultaneous confidence intervals, significant differences in the test battery of uric acid, creatinine, blood urea nitrogen and sodium in the methoxyflurane series compared with the other series was found, indicating transient impaired kidney function. Likewise, there was a significant difference between the methoxyflurane and the other series in the s.g.p.t., s.g.o.t., alkaline phosphatase and bilirubin test battery, indicating impaired liver function. This was found after doses less than 16 ml which, so far, had been considered to be without any toxic effects.
TL;DR: A semicontinuous press has been constructed for the disintegration of microorganisms and other biological material by freeze‐pressing, i.e., pressure extrusion of frozen material through a narrow hole.
Abstract: A semicontinuous press has been constructed for the disintegration of microorganisms and other biological material by freeze-pressing, i.e., pressure extrusion of frozen material through a narrow hole. The material to be freeze-pressed is frozen in the form of cylindrical rods, which fit into the pressure chamber and are extruded by a piston forced back and forth by means of a hydraulic pump. At a sample temperature of −35°C and a press temperature of −20°C, about 90% disruption is achieved in a single passage of undiluted baker's yeast (Saccharomyces cerevisiae, 270 mg/g) through the orifice of the pressure chamber. With this press about 10 kg of material can be freeze-pressed per hour.
TL;DR: In this article, the position of the Q2 head of the a3Π-X1Σ+ (0, 0) band is found to be 27 254.1 cm-1 or 3 668.13 A, which is in good agreement with the value of the singlet-triplet separation determined from earlier perturbation analysis.
Abstract: The a3Π-X1Σ+ transition of AlF has been observed in absorption by heating a mixture of AlF3 and Al powder to approximately 1 600 K in a King type furnace. The position of the Q2 head of the a3Π-X1Σ+ (0, 0) band is found to be 27 254.1 cm-1 or 3 668.13 A, which is in good agreement with the value of the singlet-triplet separation determined from earlier perturbation analysis. The (0, 0) and (1, 1) bands have been rotationally analyzed. The following equilibrium values of constants (in cm-1) have been determined for the a state: Te = 27 239.4 (1) ωe = 830.3 (3) ωexe = 4.6 (2) Be = 0.55718 (3) αe = 0.00468 (5)