Search PubMed⌕ Search

Biomedical subjects

S Ohman

Publications and source records attributed to S Ohman.

At least 55 records · Page 3Linked to original sources
PubMed1984

Reference values for CSF-IgM, CSF-IgM/S-IgM ratio and IgM index, and its application to patients with multiple sclerosis and aseptic meningoencephalitis.

Immunoglobulin M (IgM) concentrations were determined in cerebrospinal fluid (CSF) and serum (S) by enzyme-linked immunosorbent assay (ELISA). In 52 reference subjects, the upper reference limit was 0.46 mg/l for CSF-IgM, 0.32 X 10(-3) for CSF-IgM/S-IgM ratio, and 0.061 for IgM index equal to CSF-IgM X S-albumin/S-IgM X CSF-albumin ratio. No correlation to age over 15-85 years was found for any of these variables. Among 22 patients with aseptic meningoencephalitis (AM) elevated values of CSF-IgM were found in 68%, CSF-IgM/S-IgM ratio in 73%, and IgM index in 73%. The corresponding values among 35 patients with multiple sclerosis (MS) were 66%, 60% and 63%. The differences in diagnostic sensitivities for the three IgM variables were not significant. Eleven of 16 AM patients and two of 22 with MS had elevated IgM index in the presence of normal IgG and IgA indices. Determination of IgM index should therefore be performed in suspected inflammatory nervous system disorders.

Adolescent↗
PubMed1983

Evaluation of radiometer ICA1 as a routine instrument for serum ionized calcium and its application for whole blood capillary samples from newborn infants.

The Radiometer ICA1 was evaluated with four sets of samples: a) 289 serum samples sent for routine analysis of ionized calcium, b) a reference set of serum samples from 40 healthy laboratory workers, c) 42 capillary whole blood samples from healthy full-term and d) six capillary whole blood samples from pre-term infants. For comparison, all sets except the capillary samples were also run on the Orion SS-20. The ICA1 gave higher readings than the Orion SS-20 for normo-(mean difference 0.011 mmol/l) and hypocalcaemic (mean difference 0.037 mmol/l), but not for hypercalcaemic serum samples. The mean +/- 2 SD range for the serum reference set was 1.15-1.31 mmol/l for ICA1 and 1.14-1.27 mmol/l for Orion SS-20. The within-assay and between-assay precision were 0.014 and 0.032 mmol/l (SD) respectively for ICA1 and 0.010 and 0.022 mmol/l (SD) for Orion SS-20. The 42 healthy full-term infants had a mean +/- 2 SD range of 1.18-1.47 mmol/l. The six pre-term infants had whole blood ionized calcium 0.82-1.07 mmol/l. Three of them had ionized calcium less than 0.90 mmol/l and a symptomatic hypocalcemia.

Autoanalysis↗
PubMed1982

Crossed radioimmunoelectrophoretic studies of bee venom allergens.

Crossed immunoelectrophoresis (CIE) glass slides of honey bee venom showing 18 immunoprecipitates were used in crossed radioimmunoelectrophoresis (CRIE) experiments with sera from 25 patients allergic to honey bee venoms. Phospholipase A, acid phosphatase, hyaluronidase and melittin were demonstrated in the immunoprecipitates using zymographic techniques and direct hemolysis of sheep erythrocytes. The CRIE experiments verified the allergenicity of these proteins. In addition, another antigen (Ag-1) with allergenic activity was identified. This allergen is probably identical to the previously described allergen C in honey bee venom. The presence and complexity of multiple forms of the known allergenic proteins in honey bee venom, was well illustrated in the CIE/CRIE system employed.

Allergens↗
PubMed1981

Bullous amyloidosis.

The distribution pattern of amyloid deposition varies greatly in systemic amyloidosis. In primary and myeloma-associated amyloidosis, skin manifestations are common. Three patients with myeloma-associated amyloidosis had bullae or signs of increased skin fragility caused by cleavage in extensive dermal amyloid deposits. The bullae in bullous amyloidosis are, therefore, unique since they are intradermal, not subepidermal.

Aged↗
PubMed1980

Turbidimetry of inorganic sulfate, ester sulfate, and total sulfur in urine.

We describe simple and precise methods for the determination of inorganic sulfate, ester sulfate, and total sulfur in urine. The methods are based on turbidimetry of sulfate as barium sulfate in the presence of a small amount of preformed barium sulfate and with polyethylene glycol as a stabilizing agent. Inorganic sulfate is directly determined, whereas ester sulfate is measured after removal of inorganic sulfate, followed by acid hydrolysis. Total sulfur is determined after wet oxidation of the sample with nitric acid and perchloric acid in the presence of vanadate as a catalyst. We also report excretion values for healthy persons on a self-selected diet. Men excrete significantly higher amounts of inorganic sulfate and total sulfur than women, but this sex-related difference becomes insignificant if excretion values are expressed relative to creatinine.

Chromatography, Ion Exchange↗
PubMed1979

Serum calcium ion activity. Some aspects on methodological differences and intraindividual variation.

Sera were analyzed for calcium ion activity on the Orion 99-20 and SS-20 systems. Samples from 84 healthy subjects were analyzed on both systems and, because of a change of electrode composition, 74 of them were reanalyzed after this change. Additional 89 were analyzed on only SS-20. The distribution of serum calcium ion activity was close to Gaussian. The difference between the 99-20 and SS-20 readings was 0.048+/-0.017 mmol/liter (range -0.01 to 0.08) before the electrode change and -0.085+/-0.027 mmol/liter (range -0.14 to 0.02) after. The reference ranges were 1.02--1.23 mmol/liter for 99-20 and 0.93--1.20 mmol/liter for SS-20 before the electrode change. The following characteristics may contribute to differences in the readings: higher temperature, higher flow rate, new calcium and reference electrodes, new liquid junction construction and a new pumping procedure. For 74 subjects the determination of serum calcium ion activity (99-20 system) was performed with a five year interval and the difference between the first and second measurements was -0.0046+/-0.0168 mmol/liter (mean +/-SD), ranging from -0.04 to 0.03 mmol/liter. This corresponded to an intraindividual variation of 1.5%. The corresponding variations for serum total calcium and corrected calcium were 4.8% and 3.3% respectively.

Adolescent↗
PubMed1979

Method for determining thiocyanate in serum and urine.

We describe a method for rapid and specific measurement of thiocyanate in serum or urine. We separate thiocyanate from interfering compounds by adsorbing it on an anion-exchange resin that has special affinity for thiocyanate, then eluting with sodium perchlorate. The eluted thiocyanate is quantified by a modified König reaction, sodium hypochlorite being used as the chlorinating reagent. Analytical recovery of thiocyanate added to serum and urine was quantitative; the coefficient of variation was 2.3% for both within-day and between-day precision. Cyanide and certain antibiotics interfere, but may be eliminated by including additional washing steps in the usual procedure. The proposed procedure was compared with another method, based on the oxidation of thiocyanate to cyanide. Agreement was satisfactory, both for serum and urine.

Chromatography, Ion Exchange↗
PubMed1978

Determination of thiosulphate in urine.

A method is described for the determination of thiosulphate in urine. After removal of interfering compounds, including endogenous thiocyanate by ion exchange, thiosulphate is converted to thiocyanate in the presence of cyanide and cupric ions. The thiocyanate formed is concentrated by ion exchange, eluted with an acid solution of ferric ions and the ferric thiocyanate complex determined colorimetrically. Healthy human subjects excreted 31.7 +/- 12.8 mumol/24 h (mean +/- SD) thiosulphate.

Colorimetry↗
PubMed1978

Serum ionized calcium and corrected total calcium in borderline hyperparathyroidism.

We studied 25 borderline-hyperparathyroidism patients whose total serum calcium concentration was within normal limits (reference range: 2.25--2.75 mmol/liter) but whose concentrations of serum ionized calcium were above normal (reference range: 1.03--1.23 mmol/liter). Their hyperparathyroidism was histopathologically verified. To compare the discriminating value of corrected serum calcium with ionized calcium, we studied the serum calcium and albumin concentrations in a reference group of 2098 patients. After patients from endocrine and dialysis departments were excluded from the reference group, we obtained the range (mean +/- 2 SD) 2.05--2.71 mmol/liter for uncorrected serum calcium and 2.11--2.63 mmol/liter for corrected serum calcium. The correction factor for calcium on albumin was 20 mumol/g. Even with this limit for corrected serum calcium, 13 of 25 borderline hyperparathyroidism patients had values that fell within the reference range. We conclude that correcting total serum calcium values for serum albumin concentration improves discrimination of borderline hyperparathyroid patients, but that measurement of ionized calcium in serum discriminates better.

Calcium↗
PubMed1977

Clinical and immunological aspects of food allergy in childhood. I. Estimation of IgG, IgA and IgE antibodies to food antigens in children with food allergy and atopic dermatitis.

Sixtynine children with case histories of food intolerance and 30 food tolerant children with atopic dermatitis have been investigated regarding serum IgE levels and IgE-, IgG, and IgA-antibodies to some common foods. Children with food intolerance had significantly higher IgE levels and to a larger extent specific IgE antibodies to the tested allergens. IgE antibodies to cow's milk were found in 71% of the children with histories of cow's milk allergy but occurred also in similar titers in 27% of milk tolerant children with other food allergies. IgE antibodies to egg-white occurred in 88% of egg allergies, but low and moderate titers were also found in 17% of children without food intolerance. However, all children with high titers had symptoms of egg allergy. IgE antibodies to the fish allergen were only found in fish allergic children while IgE antibodies to the fish allergen were only found in fish allergic children while IgE antibodies to soy-bean and green peas were found less consistently. The level of serum IgA antibodies to milk was similar in both groups. The IgG antibody titers to all tested food antigens seemed to parallel the IgE antibody titer to the same food. It was not possible to correlate the IgG antibody titers to symptoms.

Adolescent↗