Biomedical subjects

I Olsson

Publications and source records attributed to I Olsson.

At least 91 records · Page 5Linked to original sources

PubMed1988

Epilepsy in autism and autisticlike conditions. A population-based study.

In a population-based study from Göteborg, Sweden, of infantile autism in children under age 10 years, we found epilepsy in 20% of the cases. Twice as many children among those with "autisticlike conditions" had epilepsy. All types of epilepsy were seen. Of the children in the study who had epilepsy, almost 75% (10/14) had psychomotor epilepsy. The association between autism-autisticlike conditions and epilepsy seemed to be with the behavioral disorder and not with the often concomitant mental retardation. Abnormalities evidenced on electroencephalograms seemed to be generated from the temporal regions and phylogenetically older parts of the brain in a majority of the cases.

Autistic Disorder↗

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

Fast horizontal electrophoresis. II. Development of fast automated staining procedures using PhastSystem.

The development of equipment for fast automated staining is described. It is possible to handle staining procedures with up to 20 steps and nine different solutions. To increase the reaction rate in the reaction chamber, the gels are rotated and high temperatures are used. The temperature in the reaction chamber is controlled between room temperature and 50 degrees C. Increased temperature, above 20 degrees C, generally results in faster staining and destaining. However, some reactions proceed better at a low temperature, including fixation of proteins with TCA, and the development step in silver staining, where increased temperatures cause a high background stain. Silver staining using acidic silver nitrate solution is preferred, due to easy preparation and good storage stability of the reagents. This method also causes little precipitation of silver on the walls of the reaction chamber. Silver staining is accomplished within one hour. Staining with PhastGel Blue is accomplished within 30 min.

Automation↗

PubMed1988

A tumor necrosis factor binding protein is present in human biological fluids.

Tumor necrosis factor (TNF) possesses both beneficial and toxic bioactivities. Mechanisms may operate to counteract harmful effects. We have identified a TNF binding protein (TNF-BP), which shows increased levels in serum and urine of patients on regular hemodialysis treatment (RDT). TNF-BP inhibited the specific binding of human recombinant TNF (rTNF) to its cell surface receptor. Results from gel chromatography demonstrated the presence in serum and urine of a macromolecule with an apparent molecular weight of 50,000, which formed a complex with rTNF. A 62-fold purification of TNF-BP from urine of patients on RDT was achieved by ion exchange chromatography and gel chromatography. Partially purified TNF-BP reduced the growth inhibitory effect of rTNF on a susceptible leukemia cell line. TNF-BP may act as a regulator of the biological activity of TNF and could have beneficial effects in certain inflammatory conditions.

Binding, Competitive↗

PubMed1988

Biosynthesis and processing of myeloperoxidase--a marker for myeloid cell differentiation.

Myeloperoxidase (MPO), a heme protein, is a major component of azurophilic granules of neutrophils. Optimal oxygen-dependent microbicidal activity depends on MPO as the critical enzyme for the generation of hypochlorous acid and other toxic oxygen products. MPO is synthesized during the promyelocytic stage of myeloid differentiation, the stage at which azurophilic granules are formed. Like other lysosomal enzymes, MPO is synthesized as a larger precursor which is subsequently processed and transported intracellularly to the lysosomes. The primary translation product is a single 80-kDa protein which undergoes cotranslational N-linked glycosylation to produce a 92-kDa glycoprotein. Glucosidases in the endoplasmic reticulum or early cis Golgi convert the proMPO to a 90-kDa form which is sorted into a prelysosomal compartment that undergoes final proteolytic maturation to native MPO, a pair of heavy-light protomers with subunits of 60 kDa and a 12 kDa. These events contrast with similar processes seen with other lysosomal enzymes in two ways. First, alkalinization of lysosomes with NH4+ does not alter processing or transport, in contrast to the pH dependence of these processes for other lysosomal enzymes. However, some studies indicate retardation of processing in the presence of the proton ionophore monensin. Second, intracellular transport of MPO is not apparently mediated by the mannose-6-phosphate receptor system. The gene for MPO is on the long arm of chromosome 17 (17q22, 23) near the breakpoint of the 15, 17 translocation of acute promyelocytic leukemia. The gene spans approximately 14 kb and contains 11 irons and 12 exons. The cloned full-length cDNA is approximately 2.2 kb and both normal bone marrow and cultured promyelocytic leukemia cells express two species of mRNA. Inherited MPO deficiency, a relatively common disorder, is associated with the absence of mature MPO but the presence of proMPO, consistent with a post-translational defect. Studies at the molecular level aimed at identifying the underlying genetic defect are thus far consistent with that hypothesis. In addition, the basis for the observed association between acquired MPO deficiency and some myeloid leukemias can now be studied at the molecular level using these probes.

Biological Transport↗

PubMed1988

Epidemiology of absence epilepsy. I. Concept and incidence.

An epidemiological study of absence epilepsy is presented. The study comprised a series of cases from a Swedish population, aged 0-15 years, selected on the basis of EEG criteria. All children with regular and symmetrical 3 (2-4) Hz spike-and-slow-wave complexes, recorded for the first time during the period 1978-1982, were included. A total of 134 children fulfilled the inclusion criteria, and of these, 108 (80.6%) had absences alone or in combination with general tonic-clonic seizures (GTCS); 11 (8.2%) had absences combined with other seizures; 15 (11.2%) had other types of seizures only. The mean annual incidence of absence epilepsy was 7/100,000 for children aged 0-15 years. Of these, 6.3/100,000 had absences alone or in combination with GTCS. The cumulative incidence of absence epilepsy was 98/100,000. The mean age of onset was 7 years.

Adolescent↗

PubMed1988

Use of monoclonal antibody against human neutrophil elastase in normal and leukaemic myeloid cells.

A monoclonal antibody, NP57, was produced and used against the neutrophil granule protein elastase, which selectively stain neutrophils in cryostat and paraffin wax sections. The antibody stains neutrophils and a subpopulation of monocytes in blood smears and neutrophil precursors in bone marrow smears, and gives positive reactions with the cell lines HL60 and U-937. It labelled the blast cells in 68% of cases of acute myeloid leukaemia (M1-M5) but was unreactive with all cases of lymphoid leukaemias. Most of the elastase negative myeloid leukaemias were labelled by monoclonal anti-myeloperoxidase (antibody MPO-7) as were cells from the promyelocytic line HL60. No cases of myeloid leukaemia showed the opposite pattern--that is elastase positive, myeloperoxidase negative, suggesting that the production of myeloperoxidase precedes the onset of elastase synthesis during myeloid maturation. The anti-elastase antibody NP57 is a useful addition to the range of monoclonal antibodies available for the differential diagnosis of acute leukaemia by alkaline phosphatase-antialkaline phosphatase (APAAP) labelling of cell smears; it may also be of value for the histopathological diagnosis of tumour deposits in myeloid leukaemia and for the detection of neutrophils in paraffin sections.

Antibodies, Monoclonal↗

PubMed1988

Biosynthesis and processing of lactoferrin in bone marrow cells, a comparison with processing of myeloperoxidase.

The processing and intracellular transport of lactoferrin of the neutrophil specific granules was investigated by biosynthetic labeling with (14C)leucine of bone marrow cells from healthy individuals and patients with chronic myeloid leukemia. Lactoferrin was precipitated with antilactoferrin serum and the immunoprecipitates were analyzed by sodium dodecyl sulfate (SDS), polyacrylamide gel electrophoresis (PAGE) followed by fluorography. In contrast to myeloperoxidase of azurophil granules, lactoferrin was not synthesized as a larger precursor, and it was not found to be phosphorylated. The transfer to granules of newly synthesized lactoferrin was demonstrated in pulse-chase labeling experiments followed by centrifugation of cell homogenate in a Percoll gradient. Monensin, which exchanges protons for Na+ and NH4+ cation, blocked the transfer completely, indicating a need for acidification mechanisms. Unlike myeloperoxidase, newly synthesized lactoferrin rapidly became resistant to endoglycosidase H, indicating a transport through the medial and transcisternae of the Golgi apparatus with conversion of "high mannose" to "complex" oligosaccharide side chains. Intracellular transfer of some major neutrophil azurophil and specific granule constituents is obviously regulated differently. Lactoferrin seems to be processed like proteins destined for secretion, while myeloperoxidase is processed more or less like lysosomal enzymes.

Ammonium Chloride↗

PubMed1988

Myeloid cell differentiation: the differentiation inducing factors of myeloid leukemia cells.

Mitogen-stimulated lymphocytes and some T-lymphocyte lines released a polypeptide called differentiation-inducing factor (DIF), which restored maturation of promyelocytic HL-60 cells and inhibited growth of leukemic and normal progenitor cells. Tumor Necrosis Factor (TNF), which has been found to be not identical with DIF, displayed similar effects. On the other hand, an antigenic relationship was shown between DIF and lymphotoxin (LT) by use of neutralizing antibodies. An activity, which cochromatographed with DIF during all purification steps, competed with binding of both rLT and rTNF to HL-60 cells. Approximately 2,000 binding sites for rLT were detected per cell, with a Kd of 330 pmol/l. Our observations are indications of a functional and an antigenic connection between DIF and LT, and indicate that TNF, LT and DIF share cell surface-binding sites. These binding sites are down regulated by activation of protein kinase-C. Results from modulation of the response indicated that the signal for differentiation might be transduced through activation of phospholipase A2. In order to understand myeloid differentiation and the effects of differentiation factors, we have pursued investigations of the biosynthesis and processing of one marker of myeloid differentiation, namely myeloperoxidase (MPO). Our results disclosed that MPO was synthesized as a larger precursor of Mr 90,000 to which a heme group was added, followed by proteolytic cleavage in pregranular structures to generate mature heavy Mr 60,000 and light Mr 12,000 subunits. Processing of MPO was independent of acidification. cDNA probes are now available for MPO, so that investigation of gene expression in relation to differentiation and induction of differentiation is facilitated.

Cell Differentiation↗

PubMed1987

Myeloperoxidase precursors incorporate heme.

Myeloperoxidase of neutrophil granulocytes is synthesized as a larger molecular weight precursor, which is processed to yield mature polypeptides with molecular weights of 62,000 and 12,000. We have investigated the incorporation of heme into myeloperoxidase of the human promyelocytic HL-60 cell line labeled with 5-amino[14C]levulinic acid. Myeloperoxidase was isolated by immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and radiolabeled myeloperoxidase was visualized by fluorography. A 3-h pulse labeling with 5-amino[14C]levulinic acid resulted in labeling of the Mr 90,000 and Mr 82,000 precursor polypeptides. During subsequent chase of the label, conversion to mature radioactive heavy Mr 62,000 subunit was observed but no radioactivity was associated with the mature small Mr 12,000 subunit. Peptide mapping after proteolytic cleavage with V8 proteinase showed that 5-amino[14C]levulinic acid was associated with a single Mr 23,000 polypeptide while multiple radioactive fragments were visible after proteolytic cleavage of myeloperoxidase biosynthetically labeled with [14C]leucine. That 5-amino[14C]levulinic acid was specifically incorporated into heme of myeloperoxidase was also demonstrated by dissociation under reducing conditions which yielded 14C-labeled heme as indicated by reversed phase high pressure liquid chromatography. The ionophore monensin and the base chloroquine, which block processing of myeloperoxidase, did not affect the incorporation of 5-amino[14C]levulinic acid, further supporting the notion that the incorporation of heme is independent of final processing of the polypeptide. Our data establish that heme is incorporated into myeloperoxidase already at the level of the precursor and that processing yields a heme-containing heavy subunit and a heme-free small subunit.

Aminolevulinic Acid↗

PubMed1987

Characterization of a relationship between the T-lymphocyte derived differentiation inducing factor (DIF) and lymphotoxin: a common receptor system for DIF, lymphotoxin and tumor necrosis factor downregulated by phorbol diesters.

Here we describe results which show that recombinant lymphotoxin (rLT), like the T-lymphocyte derived differentiation inducing factor (DIF), inhibited the clonogenic growth of some myeloid leukemia cell lines by concentrations of 1 to 30 pmol/l. Wild type HL-60 cells were resistant at these concentrations but responded with differentiation into monocyte-like cells at higher concentrations. An antigenic relationship between DIF and LT was indicated because a neutralizing monoclonal anti-LT antibody bound to and neutralized both differentiation and growth inhibitory effects of DIF. An activity, which cochromatographed with DIF during all purification steps, competed with binding of both rLT and recombinant tumor necrosis factor (rTNF) to HL-60 cells. By use of radioiodinated ligand, 2100 binding sites for rLT were detected on HL-60 cells with a Kd of 330 pmol/l. At 37 degrees C bound ligand was transferred to lysosomes, followed by degradation. rTNF and rLT were shown to compete for binding sites on HL-60 cells. Receptors for both rLT and rTNF were downregulated by activators of protein kinase C such as phorbol diester or diacylglycerol; the number of cell surface receptors decreased while the Kd remained unchanged. Our observations demonstrate a functional and antigenic relationship between DIF and LT and indicate that TNF, LT and DIF share binding sites on myeloid leukemia cells that are downregulated by activation of protein kinase-C.

Binding Sites↗

PubMed1987

IgG subclasses of specific antibodies in Ixodes ricinus-borne borreliosis.

Ixodes ricinus-borne borreliosis may run a protracted course. In this study we investigated the different IgG subclasses of antibodies to borreliae at different stages of the disease. In addition to the dominant subclass IgG1 and IgG3 response was found in most cases. This antibody subclass pattern with contributions of IgG2 often persists into the late stage of the disease and may last for decades. The IgG subclass response elicited by this spirochaetosis does not conform to the expected IgG4 restricted response after chronic antigenic stimulation.

Adult↗

PubMed1987

Cellular and subcellular localization of the bactericidal/permeability-increasing protein of neutrophils.

Human and rabbit polymorphonuclear leukocytes contain a bactericidal/permeability-increasing protein (BPI), a potent cytotoxin active specifically against gram-negative bacteria. To identify the cell population(s) producing BPI, we have examined mature and immature human blood cells for BPI by immunofluorescence of intact cells and radioimmunoassay and bioassay of cell extracts. By immunofluorescence and radioimmunoassay of cells from peripheral blood, BPI was detected only in neutrophils; immunofluorescent staining was punctate, indicative of the granule localization of BPI. Nearly all (greater than 90%) BPI was recovered during the subcellular fractionation of neutrophils (N2 cavitation and discontinuous Percoll gradient) in fractions containing primary granules. Little BPI was released from intact cells during degranulation (cytochalasin B and f-Met-Leu-Phe) or could be extracted from isolated granules with salt or weak acid, which suggests that most granule-associated BPI is membrane bound. Double staining of bone marrow smears for BPI and lactoferrin revealed BPI only in neutrophil precursors including (pro)myelocytelike cells lacking lactoferrin, a marker of neutrophil secondary granules. Of several human cell lines tested, only the promyelocytelike HL-60 (and to a lesser extent, KG-1) cells contained BPI. BPI was present in a more mature subpopulation (less than 25%) of untreated HL-60 cells, recognized by surface marker analysis (rosetting with IgG-sensitized sheep RBC, the absence of proliferation-associated cell surface antigen). Induction of neutrophilic or monocytic differentiation caused, respectively, a small (approximately 50%) rise or fall in the BPI content. These findings indicate that BPI is a specific product of the neutrophil lineage and, hence, of the specialized cytotoxic apparatus of the neutrophil that plays an essential role in host defense v gram-negative bacteria.

Antimicrobial Cationic Peptides↗

PubMed1986

The cytotoxic eosinophil cationic protein (ECP) has ribonuclease activity.

The eosinophil cationic protein (ECP) is a specific cytotoxic constituent of granules. In this work we demonstrated that ECP has a ribonuclease activity. Purified ECP was resolved by ion exchange chromatography into subfractions, which all showed ribonuclease activity. Another eosinophil granule protein, EPX, identical with eosinophil-derived neurotoxin (EDN) had a 125-fold higher RNase activity than ECP. ECP may exert its cytotoxic effects on parasites and cells because of its extreme basicity alone or it may be internalized and act by degrading mRNA.

Blood Proteins↗

PubMed1986

Differentiation induction in myeloid leukemic cells.

Work based on immortalised leukemic cell lines indicates that the maturation arrest in leukemia can be reversible. Successful differentiation induction would mean restoring the link between proliferation and differentiation. Human cell lines such as the promyelocytic HL-60 and the monoblastic U-937 can be induced to mature by incubation with a wide variety of agents, e.g. phorbol diesters, retinoic acid and 1,25-dihydroxycholecalciferol. In addition, mitogen-stimulated lymphocytes and some T-lymphocyte lines produce a polypeptide called the differentiation-inducing factor (DIF), which mediates maturation of HL-60 into macrophage-like cells with resulting proliferation inhibition. DIF also displays a primary growth inhibitory effect on certain subclones of the cell lines as well as on fresh clonogenic cells from patients with acute myeloid leukemia and on normal granulocyte-macrophage progenitors. Our data indicate that there is more than one way to induce differentiation in leukemia but final common pathways may exist. Complementary, synergistic, maturation effects are seen between some agents, which may become of clinical utility.

Cell Differentiation↗

PubMed1986

Erythema chronicum migrans Afzelius in Sweden. A study on 231 patients.

In order to describe the clinical manifestations of erythema chronicum migrans Afzelius (ECMA) in Sweden and to compare them with those in Lyme disease in the United States, 231 patients with ECMA were investigated. Although there are many similarities between the two disorders the findings also point to differences. The skin lesions were of longer duration (median 5-6 weeks) than those in Lyme disease but less often multiple (8%). General symptoms were found in about half of the patients with a short disease duration (less than or equal to 3 weeks), but were usually mild. Laboratory abnormalities were noted in only a minority of the cases. At the time of diagnosis none of the patients had spirochete-induced arthritis, but in three of them cardiac involvement was suspected. Among 16 untreated patients meningitis later developed in two patients and arthritis in one. Diagnostic procedures such as serologic testing and cultivation of spirochetes are discussed.

Adolescent↗

PubMed1986

Clinical manifestations of acrodermatitis chronica atrophicans in 50 Swedish patients.

A study was made of 50 consecutive patients with untreated acrodermatitis chronica atrophicans (ACA). In all patients elevated anti-spirochetal antibody titers were found at indirect immunofluorescence and enzyme-linked immunosorbent assays, and histologically biopsies exhibited a dermal lymphocytic infiltrate with a moderate to rich admixture of plasma cells and telangiectases. Nine patients had a history consistent with spontaneously healing erythema chronicum migrans Afzelius (ECMA) on the extremity on which, after 0.5-8 years, ACA lesions developed. Eight patients had a history indicating previous cranial nerve involvement and nine had had periods of severe pains in the cervical or lumbar region. Two patients had developed ECMA, facial palsy and ACA in chronological order. In 15 patients radiographic abnormalities of joints and/or bone tissue were found. Besides ACA lesions, lichen sclerosus et atrophicus- or scleroderma-like lesions were found in six patients. The inflammatory ACA lesions were sometimes discrete and had been overlooked. Joint deformities, sclerotic lesions, diffuse edema or pain were the cardinal symptoms in some patients. The findings indicate that clinical recognition of ACA may be difficult and that a combination of clinical, histopathologic and serologic findings may be necessary to establish the diagnosis. The results are consistent with the concept that ACA is a late manifestation of infection by the same spirochete as causes ECMA and Bannwarth's syndrome.

Acrodermatitis↗

PubMed1986

Joint and bone involvement in Swedish patients with Ixodes ricinus-borne Borrelia infection.

The presence of signs of joint involvement was investigated in 231 patients with erythema chronicum migrans Afzelius (ECMA), in 50 patients with acrodermatitis chronica atrophicans (ACA), in four patients with spirochete-induced facial palsy and in one patient with pericarditis and serologic evidence of Borrelia spirochetal infection. Only one of 16 untreated patients with ECMA developed arthritis. The patient with pericarditis had suffered from arthritis for 2 months when the cardiac symptoms developed. Thirteen of the patients with ACA had luxations/subluxations of small joints in the hands or feet and/or arthritis in large joints. In four of the patients with ACA, periosteal thickening of bones was found. The results indicate that joint abnormalities are not uncommon in patients with ACA. However, arthritis during the first year of tick-borne spirochetal infection was less common in Sweden than has been reported among patients with Lyme disease in the United States.

Acrodermatitis↗