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Biomedical subjects

B M Eriksson

Publications and source records attributed to B M Eriksson.

At least 37 records · Page 2Linked to original sources
PubMed1994

On-line solid-phase extraction with automated cartridge exchange for liquid chromatographic determination of lipophilic antioxidants in plasma.

A fully automated liquid chromatographic method is described based on a Prospekt solid-phase extraction unit for the analysis of lipophilic indenoindolic antioxidants in plasma. Plasma samples, mixed with internal standard, were injected onto C8-cartridges. After washing, the samples were eluted and transferred to a C8-analytical column, where separation was performed. The eluent was monitored by electrochemical detection. Owing to the nature of the drugs investigated care had to be taken to avoid adsorption losses in vials and capillaries. The method, which was found to give excellent recoveries (100.9%, n = 8) and repeatability (R.S.D. +/- 1.7%), is time-saving compared to a previously used assay with sample work-up by liquid-liquid extraction.

Adsorption↗
PubMed1994

Seroreactivity to Pneumocystis carinii in patients with AIDS versus other immunosuppressed patients.

The aim was to study the humoral response to Pneumocystis carinii and its diagnostic use in patients with P. carinii pneumonia (PCP). The antibody response was measured by indirect immunofluorescence in AIDS patients versus other immunosuppressed patients with 122 episodes of confirmed PCP. During the early acute stage of the pneumonia, anti-P. carinii antibodies were found in 17% of AIDS and 24% of other immunosuppressed patients. In the second serum sample, antibodies were still found in 17% of the AIDS patients but in as many as 56% of the otherwise immunosuppressed patients. Antibodies were also found in 17% of HIV-positive and 15% of other immunosuppressed control patients, but only in 3% of immunocompetent controls (p < 0.001). Paired sera were available from 55 patients during 58 PCP episodes. Seroconversion or a fourfold rise in titre was detected in only 1/36 (3%) AIDS patients but in 10/22 (45%), (95% c.i.: 24-66%) other immunosuppressed patients (p < 0.001). We conclude that AIDS patients seem to have lost their ability to develop a humoral response to P. carinii during pneumonia, whereas many other immunosuppressed patients do respond. In these patients the serological test against P. carinii was of no diagnostic value in the acute phase of the infection, whereas when analysing paired sera it was a useful complement to the clinical diagnosis.

AIDS-Related Opportunistic Infections↗
PubMed1993

Diagnosis of cytomegalovirus in bronchoalveolar lavage by polymerase chain reaction, in comparison with virus isolation and detection of viral antigen.

Bronchoalveolar lavage (BAL) products from 52 immunocompromised patients with symptoms of pulmonary infection was examined for cytomegalovirus (CMV) by virus isolation, polymerase chain reaction (PCR) and detection of CMV antigen by immunofluorescence or immunoperoxidase staining after short-term incubation in tissue culture and directly in BAL cells. We found that PCR detected all cases positive by virus isolation (15/52 samples) and the result was obtained within 5 h. PCR detected more cases of CMV than did virus isolation (22/52 samples). Positive PCR and negative virus isolation were consistent with probable CMV infection in 3/7 patients when other clinical and laboratory parameters of CMV infection were considered. The negative predictive value of PCR was high; none of 30 patients negative by PCR developed CMV pneumonia within the subsequent 2 months. Detection of CMV antigen after short-term incubation was rapid enough to be used in clinical practice, specific (100%) and with a sensitivity of 60%. Demonstration of CMV antigen in alveolar cells was highly specific (100%) but had too low a sensitivity (26.7%) to be used as the only rapid method. Our conclusion is that a combination of PCR and detection of CMV antigen after short-term incubation and directly in alveolar cells is optimal for rapid identification of CMV.

Adolescent↗
PubMed1992

Determination of catecholamines in urine by liquid chromatography and electrochemical detection after on-line sample purification on immobilized boronic acid.

Norepinephrine, epinephrine and dopamine in urine were measured by an automated liquid chromatographic method. After sample purification on a column containing silica-immobilized boronic acid, which showed great affinity for catecholamines at neutral pH, the catecholamines were eluted by backflushing with an acidic mobile phase and transferred to a cation exchanger for separation. Detection was performed electrochemically and the relative standard deviation was 2% for the analysis of endogenous concentrations in human urine.

Boronic Acids↗
PubMed1992

Polymerase chain reaction with double primer pairs for detection of human parvovirus B19 induced aplastic crises in family outbreaks.

Parvovirus B19 DNA can be detected by polymerase chain reaction with double primer pairs (nested PCR). Recent infection was documented by a retrospective serological study using Parvoscan-B19 enzyme linked immunosorbent assay (EIA) for detection of B19 human parvovirus IgM and IgG antibodies in serum or plasma specimens. In 3 families B19 outbreaks caused aplastic crises necessitating blood transfusion in 5 children and 1 adult with hereditary sphaerocytosis. Four members from 2 of the families had clinically overt haemolytic anaemia prior to the event. Two members in another family presented with an aplastic crisis disclosing the underlying chronic haemolytic disease. All 7 patients were identified as PCR positive in serum samples taken 3-14 days after the onset of symptoms. Comparison with dot blot hybridization revealed detectable DNA in only 2/3 PCR positive patients. Thus, nested PCR is more sensitive than the dot blot hybridization method and is therefore a suitable complement to the antibody assay for identifying recent B19 infection.

Adolescent↗
PubMed1991

Determination of vanilmandelic acid in urine by coupled-column liquid chromatography combining affinity to boronate and separation by anion exchange.

An automated liquid chromatographic method for assaying vanilmandelic acid in urine is described. Vanilmandelic acid and potential interfering substances, such as catechol compounds and their metabolites, have been tested for affinity to boronic acid-substituted silica at various pH values. Vanilmandelic acid and the internal standard, isovanilmandelic acid, were bound to the boronate matrix at an acidic pH, whereas for instance catecholamines were unretained and passed through the column. The alpha-hydroxycarboxylic acids were then desorbed by another mobile phase (pH 6.0) and transferred to an anion exchanger for chromatography and electrochemical detection. A relative standard deviation of 2.8% was obtained for the analysis of human urine samples containing 6.6 microM vanilmandelic acid.

Boron Compounds↗
PubMed1990

Determination of urinary vanillylmandelic acid by direct injection and coupled-column chromatography with electrochemical detection.

An automated column-switching system for determination of vanillylmandelic acid in urine is described. The liquid chromatographic system was composed of two separation columns with different selectivity properties, an octadecyl column coated with tributyl phosphate as stationary liquid phase and a silica-based anion exchanger. Urine samples were injected directly onto the first column, where vanillylmandelic acid was separated from the main part of the sample matrix. The internal standard isovanillylmandelic acid was co-eluting with vanillylmandelic acid, and a fraction of the eluate containing both substances was switched to the second column, where separation was performed. To assess peak purity, detection was performed with dual working electrodes in parallel mode. A relative standard deviation of 3.5% was obtained for determination of human urine samples containing 3 microM vanillylmandelic acid, and less than 0.1 microM could be detected.

Chromatography, Liquid↗
PubMed1990

Early detection of cytomegalovirus in cell culture by a new monoclonal antibody, CCH2.

A CMV monoclonal antibody, CCH2, produced in this laboratory was evaluated for rapid detection of CMV. Two staining procedures, immunofluorescence and an immunoenzymatic technique using biotin-streptavidin peroxidase, were compared. The CCH2 monoclonal antibody was used to demonstrate early CMV antigen in cell culture 24 h after inoculation of 598 urine samples from kidney transplanted patients by indirect immunofluorescence in comparison with virus isolation. One hundred and sixty of the specimens were stained additionally by an immunoenzymatic technique and the results were compared. CMV was isolated from 170 out of 598 specimens within 6 weeks. Early CMV antigen was demonstrated in 114 of these specimens by immunofluorescence giving a sensitivity of 67% and a specificity of 95%. In the comparison with the immunoenzymatic staining procedure the results for all three tests agreed for 81% (130/160) of the specimens. After resolving discordant results into true positives and true negatives, the sensitivity was 87, 85 and 70%, respectively for virus isolation, immunoenzymatic staining and immunofluorescence and the specificity 100, 96 and 99%. The CCH2 monoclonal antibody proved to be useful for rapid detection of CMV in urine specimens and using immunoenzymatic staining with biotin-streptavidin a sensitivity comparable to that of virus isolation was found.

Antibodies, Monoclonal↗
PubMed1989

Colonization with potentially pathogenic respiratory tract bacteria. A household study.

A group of 235 persons (180 adults and 55 children 0-15 years old) recorded symptoms of upper respiratory tract infection daily during two three-month periods (autumn 1986 and spring 1987). Samples for culture were taken from the nasopharynx and throat once during each period. Fifteen per cent of asymptomatic subjects harboured respiratory pathogens in the nasopharynx, as did 28% of those subjects with minor respiratory tract infections and 46% of those with more severe respiratory tract infections. Of children up to seven years of age, 58% were colonized with potential respiratory pathogens, which is important to keep in mind when evaluating culture reports from young children. Adults living with young children were colonized significantly more often than other adults. Branhamella catarrhalis was the most common pathogen.

Adolescent↗
PubMed1988

Determination of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid in plasma by direct injection in coupled-column liquid chromatography with electrochemical detection.

A method is described that allows determination of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in platelet-poor human blood plasma after direct injection of 50-100 microliters of plasma into a coupled-column liquid chromatographic system. The chromatographic system comprised an enrichment column and two separation columns with different selectivity properties. The samples were injected into the C18 enrichment column, which was eluted with a buffer solution as the mobile phase. 5-HT, 5-HIAA and the internal standard 5-hydroxy-N-methyl-tryptamine (5-HMT) were then desorbed by a stronger mobile phase and flushed into a cation exchanger, which separated 5-HT and 5-HMT. 5-HIAA passed straight through and was switched to a C18 column where it was retarded. After 5-HT and 5-HMT had been eluted from the cation exchanger and detected, the eluate from the C18 column was directed to the detector and 5-HIAA was determined. Basic plasma levels, about 4 nM for 5-HT and 30 nM for 5-HIAA, were measured with a relative standard deviation of about 5%.

Animals↗
PubMed1988

Human parvovirus B19 infection with severe anemia affecting mother and son.

Two patients, a 43-year-old mother and her 12-year-old son developed severe anemia after a disease with fever, myalgia, rash and gastrointestinal symptoms. The infectious proved to be caused by human parvovirus B19 (IgM antibody titer rises). Investigations revealed that both patients suffered from spherocytosis, apparently hereditary and not known before. This emphasizes the importance of thorough hematological investigations in patients showing symptoms resembling a viral disease when seen in connection with severe anemia in order to reveal underlying chronic hemolytic disease. In patients with these diseases transient aplastic crisis will give a much more pronounced anemia than in otherwise healthy individuals.

Adult↗
PubMed1987

Liquid chromatographic method for the determination of 3,4-dihydroxyphenylethylene glycol and 3,4-dihydroxymandelic acid in plasma.

A method is described for the simultaneous determination of the deaminated catecholamine metabolites 3,4-dihydroxyphenylethylene glycol (DOPEG) and 3,4-dihydroxymandelic acid (DOMA) in plasma by liquid chromatography with amperometric detection. The compounds are extracted from plasma by adsorption on alumina, then separated on a reversed-phase column coated with tributyl phosphate as the stationary liquid phase. It is a simple and selective method that permits the determination of basal levels of DOPEG and DOMA in plasma with a relative standard deviation of 3%.

Chromatography, Liquid↗
PubMed1987

Early posthypoglycemic insulin resistance in man is mainly an effect of beta-adrenergic stimulation.

The insulin effect following hypoglycemia was studied with the euglycemic clamp technique in seven healthy subjects. Following an initial euglycemic clamp hypoglycemia was induced and after glucose recovery a second clamp was performed. Glucose production (Ra) and utilization (Rd) were studied with [3-3H]glucose. Each subject was studied four times; during infusion of placebo, propranolol, somatostatin, and a control study where hypoglycemia was prevented. Hypoglycemia induced an insulin resistance with a lower steady state glucose infusion rate following the hypoglycemia during placebo as compared to the control study (2.5 +/- 0.5 and 4.8 +/- 1.0 mg/kg min, respectively, P less than 0.05). The insulin resistance was due to an attenuated insulin effect on both inhibition of Ra (impaired by 37%) and stimulation of Rd (impaired by 61%). The insulin-antagonistic effect was completely prevented by propranolol but only partly by somatostatin. Thus, early posthypoglycemic insulin resistance (2.5-3.5 h after hypoglycemia) is a sustained effect mainly due to beta-adrenergic stimulation.

Adult↗
PubMed1986

Studies on the insulin-antagonistic effect of catecholamines in normal man. Evidence for the importance of beta 2-receptors.

The insulin-antagonistic effect of adrenaline was studied in seven healthy subjects with the euglycaemic clamp technique using two insulin infusion rates (40 and 1200 mU X (m2)-1 min-1). The adrenergic receptor mediating the adrenaline effect was characterized by concomitant infusion of propranolol (beta 1 + beta 2-antagonist) or metoprolol (beta 1-antagonist). Each subject was studied four times (placebo, adrenaline, adrenaline + propranolol, adrenaline + metoprolol). Glucose turnover was measured with D(3-3H)-glucose. Similar plasma insulin levels were reached in all studies with the two insulin infusion rates (mean; placebo 51 +/- 3 and 7421 +/- 337 mU/l respectively). Glucose production was completely inhibited by the low insulin level during placebo infusion. Adrenaline antagonized this effect so that a significant glucose production was seen at the low but not at the high insulin level. Propranolol, but not metoprolol, reversed this insulin-antagonistic effect of adrenaline. Glucose utilization increased from 2.53 +/- 0.17 to 7.28 +/- 0.88 mg X kg-1 X min-1 during placebo when the insulin levels were increased from 4 +/- 0.3 to 51 +/- 3 mU/l. Increasing the insulin levels 150-fold to approximately 7500 mU/l only doubled the glucose utilization (14.68 +/- 1.14 mg X kg-1 X min-1). Adrenaline induced a pronounced inhibition of glucose utilization at both insulin levels (78% and 37% inhibition respectively). Propranolol, but not metoprolol, prevented this effect of adrenaline. Thus, physiological adrenaline levels exert a pronounced insulin-antagonistic effect which is mediated by beta 2-receptor stimulation. The inhibitory effect on glucose uptake is maintained even at high insulin levels when hepatic glucose production is completely abolished.

Adult↗
PubMed1985

Nervous control of the blood pressure in the Atlantic cod, Gadus morhua.

Dorsal (PDA) and ventral aortic blood pressure (PVA) and heart rate (HR) were measured in conscious resting cod, Gadus morhua L., which has been allowed 24 h recovery from surgery. Plasma adrenalin and nonadrenalin concentrations in these fish were 3.4 and 2.2 nmoll-1 respectively, and thus lower than previously reported values from partially recovered cod. Twenty-four hours after treatment with the adrenergic neurone blocking agent bretylium, PDA was significantly reduced by 17% compared to sham-injected controls, although PVA and heart rate were unaltered. Subsequent alpha-adrenoceptor blockade by phentolamine produced no further fall in PDA and no changes in PVA or HR, provided a 5-h period was allowed to overcome the acute toxic side effects of phentolamine. The effectiveness of the bretylium or phentolamine blockade was confirmed by noting the absence of any vasoconstrictor response during sympathetic nerve stimulation in perfused tails from fish used in the in vivo experiments. Bretylium had no significant effect on the sensitivity of the isolated coeliac artery to adrenalin, but effectively blocked the adrenergic innervation of this artery or the vasculature of the tail. Evidence for a non-selective blockade of non-adrenergic nerves to the heart was also obtained. It is concluded that the adrenergic tonus affecting the dorsal aortic blood pressure in resting cod that have recovered for 24 h following surgery is due solely to an adrenergic nervous tone.

Animals↗
PubMed1984

Determination of 3,4-dihydroxyphenylethylene glycol and 3,4-dihydroxyphenylacetic acid in blood plasma by liquid chromatography with amperometric detection.

Liquid chromatography with amperometric detection was employed for the determination of the dihydroxycatecholamine metabolites, 3,4-dihydroxyphenylethylene glycol (DOPEG) and 3,4-dihydroxyphenylacetic acid (DOPAC) in plasma. The compounds were isolated from plasma by adsorption onto alumina, the elution from which was found to be strongly dependent on the acid used. Conditions for the separation on octadecyl-bonded silica were evaluated with particular reference to the influence of pH, ion-pairing anions and quaternary ammonium ions. Recoveries of ca 85% and relative standard deviations of about 3% were obtained for the assay of endogenous concentrations.

Journal Article↗
PubMed1983

Determination of catecholamines in urine by ion-exchange liquid chromatography with electrochemical detection.

A liquid chromatographic method for the determination of free urinary concentrations of epinephrine, norepinephrine and dopamine is presented. For urine samples, pre-purified by adsorption onto alumina, ion-exchange chromatography was, in terms of selectivity, found to be superior to the more widely used reversed-phase chromatography. The column eluates were monitored with an electrochemical detector utilizing a glassy carbon working electrode. The method allows determination of the concentrations in 0.5 ml of normal urine samples with a relative standard deviation below 2%.

Catecholamines↗