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Biomedical subjects

B Olsson

Publications and source records attributed to B Olsson.

At least 91 records · Page 5Linked to original sources
PubMed1988

Fast horizontal electrophoresis. I. Isoelectric focusing and polyacrylamide gel electrophoresis using PhastSystem.

PhastSystem, an integrated system for horizontal electrophoresis and isoelectric focusing in small gels, including automated staining and destaining, is described. Buffers for electrophoresis are supplied to the gel from buffer strips made of agarose. The separation bed is cooled by Peltier elements. All conditions of significance to the results, both during separation and development, are controlled by a microprocessor. For separation, nine programs are available, each with 9 steps; for development, there are nine programs with 20 steps each. In this paper, we also report results using PhastSystem for purity checking and characterization of monoclonal antibodies after affinity chromatography and also for determining their digestion rate with papain.

Buffers↗
PubMed1988

Blotting from PhastGel media after horizontal sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

An improved procedure, "thermoblotting", is described for transferring proteins by diffusion from PhastGel Gradient media to an immobilizing matrix after horizontal sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After electrophoresis the gels were left on the separation bed of PhastSystem, the blotting matrix was applied and a transfer temperature was selected between 5-70 degrees C. An experimental series at fixed diffusion times showed that the transfer yield was significantly increased with temperature. The evaluation was done visually after staining of the blots with colloidal gold. An evaluation study comparing nitrocellulose, nylon, and polyvinylidenedifluoride of different pore sizes is also reported. Finally, the transfer efficiencies for 125I-labelled bovine serum albumin and soybean trypsin inhibitor were estimated using four different blotting procedures: two diffusion blotting techniques and two electrophoretic blotting techniques (tank vs. semi-dry).

Collodion↗
PubMed1988

Pharmacokinetics and bioavailability of reduced and oxidized N-acetylcysteine.

The pharmacokinetics and bioavailability of N-acetylcysteine (NAC) have been determined after its intravenous and oral administration to 6 healthy volunteers. According to a randomized cross-over design each subject received NAC 200 mg i.v. and 400 mg p.o., and blood samples were collected for 30 h. Reduced NAC had a volume of distribution (VSS) of 0.59 l.kg-1 and a plasma clearance of 0.84 l.h-1.kg-1. The terminal half-life after intravenous administration was 1.95 h. The oral bioavailability was 4.0%. Based on total NAC concentration, its volume of distribution (VSS) was 0.47 l.kg-1 and its plasma clearance was 0.11 l.h-1.kg-1. The terminal half-life was 5.58 h after intravenous administration and 6.25 h after oral administration. Oral bioavailability of total NAC was 9.1%.

Acetylcysteine↗
PubMed1988

Improved isolation of mycobacteria other than Mycobacterium tuberculosis on isoniazid-containing Löwenstein-Jensen medium.

The benefit of including isoniazid-containing Löwenstein-Jensen medium for primary isolation of mycobacteria was evaluated in 3,726 clinical specimens. This media increased the primary isolation of mycobacteria other than Mycobacterium tuberculosis by 9.2%, facilitated macroscopical reading and aided presumptive identification of the isolated mycobacteria.

Culture Media↗
PubMed1987

Enzyme electrodes and their application.

Starting from the state of the art, principles for improving the analytical characteristics of enzyme electrodes are discussed. Coupling of appropriate amperometric electrode processes with enzyme systems, e.g. urease or aminopeptidases, results in a simplification of operation. Optimal sample frequencies are realized on the basis of enzyme membranes, with both a small characteristic diffusion time and a high enzyme activity, applied in a well-designed sample-processing system. Coupled enzyme reactions of the sequence or competition type are successfully used for extension to new analytes, e.g. inhibitors, cofactors or alternative substrates. Cyclization of the analyte enhances the sensitivity of enzyme electrodes to the nanomolar concentration range. Enzymic anti-interference layers are a tool for improving the sensor specificity. The operational characteristics of enzyme electrodes are thus adaptable to any given analytical problem.

Biotechnology↗
PubMed1987

Autistic traits in the Rett syndrome.

Reactions to acoustic, visual, tactile and gustatory stimuli and to social contact were recorded in a group of girls with the Rett syndrome and in two groups of girls fulfilling the criteria for the infantile autistic syndrome. The autistic syndrome was not found in several subjects in all the Rett syndrome age groups and, when it was found, it was not of the same form as in the other subject groups. It was concluded that the behavioral syndrome of autism is of little value for differential diagnosis between the Rett syndrome and primary infantile autism.

Autistic Disorder↗
PubMed1987

Autism and Rett syndrome: behavioural investigations and differential diagnosis.

The most common wrong diagnosis of children with Rett syndrome has been the infantile autistic syndrome, and it is probable that this false diagnosis continues to be made in many places. This paper is a follow-up to the authors' previous study concerning differential diagnosis between the two syndromes and is based on the observation of 63 patients over the age of 22 months in 10 stimulus situations. In Rett syndrome there were very small individual differences in the sensorimotor performances, which correspond only to the third and fourth stages of Piaget's 'sensorimotor intelligence' scale. There were pronounced individual differences in the levels of basic motor development and, independently from these, in autistic behavioural traits. When the children's behaviour was examined in detail, it became evident that girls with Rett syndrome differ in many subtle ways from those with the autistic syndrome. Behaviour observed in some cases of Rett syndrome but in none of the autistic syndrome included: social (non-autistic) behaviour; no chewing, at most sucking of items of food placed in the mouth; monotonous 'hand-washing' movements with arms flexed in front of chest or chin. In all cases of Rett syndrome but in only some of the autistic syndrome there were: no 'social defence reactions' nor 'primary self-injuring activities'; some form of ataxia and a very restricted repertoire of postures and movements, monotonous in form and speed; and the time spent looking at objects and people was at least as long as the time taken to manipulate objects. Some causes of the characteristic stereotypic hand movements observed in Rett syndrome are also suggested.

Age Factors↗
PubMed1987

Diagnosis of pulmonary tuberculosis by selected-ion monitoring: improved analysis of tuberculostearate in sputum using negative-ion mass spectrometry.

Coded sputum specimens from patients with tuberculous (8 specimens) and nontuberculous (15 specimens) pneumonia were analyzed for tuberculostearic acid by selected-ion monitoring of the pentafluorobenzyl ester derivative by using negative-ion mass spectrometry. The analytical results agreed with those from culturing of the specimens, except in three cases in which the chromatograms were difficult to interpret owing to insufficient amounts of sputa available. Negative-ion mass spectrometry provided superior sensitivity and selectivity for detection of tuberculostearic acid compared with the previously used gas chromatographic-mass spectrometric methods. The technique reported here should have considerable potential for the rapid diagnosis of pulmonary tuberculosis by direct analysis of sputum.

Gas Chromatography-Mass Spectrometry↗
PubMed1986

Shift to righthandedness in Rett syndrome around age 7.

This paper confirms Nomura's finding (Nomura et al, 1984) that almost all of those children with Rett syndrome under 7 who grasp objects are lefthanded. It is suggested that the lefthandedness in Rett syndrome up to age 7 comes from a functional lateralization of the cerebral hemispheres similar to that which Birkmayer and Rett proposed for normal infants up to age 1 (Birkmayer and Rett, 1954). However, examination of children over 7 showed that almost all of those patients who grasp objects prefer the right hand and show symptoms of disturbance of the functions of the pyramidal tract that are more pronounced in the left than in the right upper limb. It is suggested that in connection with the severe developmental retardation of the CNS in Rett syndrome the right shift factor of handedness (Annett, 1981) has a belated manifestation. Within the framework of a regression of the CNS there occurs a regression which is more pronounced in the right cerebral hemisphere than in the left.

Adolescent↗
PubMed1986

Excretion of noscapine in human breast milk.

The excretion of noscapine in human breast milk was studied in 8 lactating women given a single oral dose of 100 or 150 mg after a light breakfast. Serum and milk samples were collected for 24 h after drug intake. Although noscapine is a weak base, only a small amount was excreted in the milk. The median milk/serum ratio was 0.29, range 0.15-0.88. The noscapine dose received by a child during a 24 hour period, when the maternal dose is 50 mg t.i.d., was calculated to be 0.8 (0.4-1.9) micrograms/kg (median and range).

Adult↗
PubMed1986

Diagnostic accuracy of two-dimensional echocardiography combined with Doppler echocardiography in neonates and infants with cardiac symptoms.

In a previous study the diagnostic accuracy of two-dimensional echocardiography was demonstrated. In a review of our clinical material from the last three years the additional value of Doppler echocardiography was evaluated. Doppler echocardiography did improve the diagnostic accuracy in a few groups of patients (patent ductus arteriosus, aortic stenosis and to some extent coarctation of the aorta). The main value of Doppler was however the possibility to obtain information about flow patterns, valve obstruction or regurgitation.

Child, Preschool↗
PubMed1985

Absorption of iohexol from cerebrospinal fluid to blood: pharmacokinetics in humans.

The absorption of iohexol from the subarachnoid space was studied in 9 patients. Serum concentrations of iohexol were measured for a minimum of 24 hours after injection. Peak serum concentrations were observed after 2.2 (1.7-2.7) hours. The half-life of the subsequent decrease in serum concentrations was 3.4 (2.2-7.9) hours. Concentrations of iohexol in cerebrospinal fluid were 0.29-4.3 mg I/ml 24 hours after injection (7 patients). Serum and cerebrospinal fluid concentrations of iohexol are comparable to those found after intrathecal injection of metrizamide.

Adult↗