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Biomedical subjects

C Andersson

Publications and source records attributed to C Andersson.

At least 109 records · Page 6Linked to original sources
PubMed1994

Roller and centrifugal pumps compared in vitro with regard to haemolysis, granulocyte and complement activation.

A Biomedicus centrifugal pump and a Polystan roller pump were compared in vitro with regard to differences in haemolysis, granulocyte and complement activation. Six circuits of tubing and oxygenators were connected to each pump. Heparinized fresh human blood was circulated for 72 hours in the systems. Blood samples were drawn at defined intervals. Haemolysis was assessed by determination of lactate dehydrogenase (LD) and potassium, and granulocyte activation by quantification of the granulocyte proteins calprotectin, lactoferrin and myeloperoxidase. Complement activation was assessed by measuring C3 activation products (C3b, iC3b and C3c), and the terminal C5b-9 complement complex (TCC). The results indicate more haemolysis and complement activation in the roller pump group, revealed by significantly higher concentrations of LD, potassium, C3 activation products and TCC. Calprotectin, lactoferrin and myeloperoxidase were all significantly increased in both groups, but the rise appeared earlier in the roller pump group. The concentrations of LD and potassium both correlated significantly with C3 activation products, indicating that complement activation may at least partly be responsible for the haemolysis.

Cell Adhesion Molecules, Neuronal↗
PubMed1993

New method for the isolation of polyglycosylceramides from human erythrocyte membranes.

A new procedure was developed for the isolation of long-chain, highly polar glycosphingolipids from human erythrocytes. The membrane material left after extraction of membrane lipids with organic solvents was peracetylated in a mixture of formamide, pyridine and acetic anhydride, and the acetylated products were then extracted with chloroform. The material was fractionated and purified by means of Sephadex LH-20, Sephadex LH-60 and silica-gel chromatography. The final preparations were mixtures of highly polar glycosphingolipids containing from 7 to 31 sugar residues relative to sphingosine. GC-MS analysis of the sugar part of the isolated fractions showed the presence of branched polyglycosyl chains of N-acetyllactosaminyl type. Endo-beta-galactosidase (Bacteroides fragilis) liberated from the deacetylated material two glycosphingolipids, which were identified by fast atom bombardment-mass spectrometry as Hex-Cer and HexNAc-Hex-Hex-Cer with sphingosine and mainly 24 and 22 carbon fatty acids. Endoglycoceramidase (Rhodococcus) degraded polyglycosylceramides to free ceramides and free polysaccharides. The released sugars were fractionated by high-pH ion-exchange chromatography into fractions differing in sialic acid content. The procedure presented in this paper can be used for large and small scale preparations of complex glycosphingolipids. It proved to be especially suitable for screening for polyglycosylceramides in different tissues.

Carbohydrate Sequence↗
PubMed1993

Human liver microsomal glutathione transferase. Substrate specificity and important protein sites.

Human liver microsomal glutathione transferase displays the following glutathione peroxidase/transferase activities: dilinoleoylphosphatidylcholine hydroperoxide (0.03 and 0.17 mumol/min.mg, unactivated and N-ethylmaleimide-activated enzyme, respectively), linoleic acid hydroperoxide (0.09 and 0.15 mumol/min.mg), cumene hydroperoxide (0.04 and 3 mumol/min.mg), methyl linoleate ozonide (0.02 and 1.2 mumol/min.mg) and 1-chloro-2,4-dinitrobenzene (1.9 and 24 mumol/min.mg). The activation of glutathione peroxidase activities are much higher than previously observed. The activity towards a phospholipid hydroperoxide is noteworthy since protection against lipid peroxidation has been implied. Methyl linoleate ozonide has not previously been characterised as substrate for any microsomal glutathione transferase. Human liver microsomal glutathione transferase displays an isoelectric point of 9.4 and a structure in agreement with that deduced from the cDNA sequence. Gel electrophoretic analysis shows that proteolytic activation of the human enzyme corresponds to cleavage at Lys-41, thus defining the critical activation site.

Amino Acids↗
PubMed1993

Enantioselective lipase-catalyzed ester hydrolysis: effects on rates and enantioselectivity from a variation of the ester structure.

In order to make a preliminary study of substituent effects on the rate and enantioselectivity obtained in esterolytic reactions catalyzed by a lipase from Candida rugosa, a series of racemic esters, derived from some alpha-alkyl and alpha-halo phenylacetic acids, were prepared. The reactions were studied at pH 6.0 and 50 degrees C under which conditions uncatalyzed hydrolysis was relatively slow. Reaction samples were studied at different points of time by means of analytical chiral reversed-phase liquid chromatography, which permitted the simultaneous determination of product enantiomeric excess and of the degree of total ester hydrolysis. These data were then used to calculate initial rates as well as enantioselectivity. An increase of the steric bulk of the alpha-substituent was found to highly decrease the rate of the reaction. On the other hand, rates were higher for the p-nitrophenyl esters than for the corresponding 2-chloroethyl esters. Consistently, the enantioselectivity was found to be higher for the latter type of ester. The esters of the alpha-halo (bromo and chloro) phenylacetic acids gave mandelic acid as the final product. This was caused by a rapid solvolysis of the alpha-halo phenylacetic acid initially formed.

Candida↗
PubMed1993

Acute-phase proteins in response to tumor growth.

This study has evaluated the relationship between tumor growth and induction of acute-phase proteins. It has also determined whether an intact cellular immunity is obligatory for a fully expressed acute-phase plasma protein response in the presence of a highly antigenic tumor. Quantitatively, acute-phase responses (protein synthesis, plasma concentrations, hepatic RNA content, anorexia) were proportional to tumor burden. Anti-inflammatory drugs (indomethacin 1 micrograms/g body wt, dexamethasone 0.5 micrograms/g body wt) had no direct effect on the attenuation of the systemic acute-phase responses, but did affect them indirectly by decreasing tumor growth. Immune suppression (cyclosporine A at 20 or 60 micrograms/g body wt) had no effect on either acute-phase reactions or local tumor growth. In endotoxin-stimulated (lipopolysaccharide) normal mice, immune suppression aggravated anorexia and caused high mortality, while dexamethasone partly reversed these effects in endotoxin-stimulated mice. Plasma levels of acute-phase proteins correlated to circulating levels of IL-6 in untreated tumor-bearing mice, but this relationship was not obvious in either drug-treated tumor-bearing or endotoxin-stimulated mice. Tumor tissue induced the synthesis of different acute-phase proteins compared to endotoxin. However, disintegrated normal liver tissue induced the synthesis of serum amyloid protein to the same extent as the growing tumor. This effect was primarily associated with the mitochondrial/lysosomal and microsomal liver cell fractions. In conclusion, the overall acute-phase protein response is not a modulating factor of tumor growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute-Phase Proteins↗
PubMed1993

Transplantation of cultured type 1 astrocyte cell suspensions into young, adult and aged rat cortex: cell migration and survival.

The present study examined the fate and migration of transplanted astrocytes in different host ages. Additionally, the effect of donor cell age was examined in relation to cell migration. Cultured astrocytes from 5, 12 and 30 days in vitro were transplanted into young (postnatal day 5 and 21), adult (4.5 month), and aged (21 month) animals. The transplanted cells were labeled with Fast Blue, Fluorogold or DiI. The results confirmed previous studies demonstrating that transplanted cells were able to migrate successfully through host central nervous system and extended those findings to show that the age of the host significantly influenced donor cell migration distance. Migration was most extensive in young animals, as conditions supporting cell migration appeared to be lacking in older animals. Donor cells preferentially migrated on myelinated fiber tracts, rather than on unmyelinated fiber tracts or gray matter. The donor cells were not glial fibrillary acidic protein positive, indicating that either the cultured type 1 astrocytes did not survive transplantation or underwent significant remodeling of the intermediate filament network. It is also possible that a subpopulation of cells, possibly immature astrocytes which are present in the transplanted cell suspensions, flourished and subsequently migrated in the host brains.

Aging↗
PubMed1993

Socio-demographic characteristics of women requesting induced abortion. A cross-sectional study from the municipality of Malmö, Sweden.

The aim of this study in an urban population has been to describe socio-demographic characteristics of women seeking an induced abortion. The 1,220 cases in the study correspond to an annual abortion rate of 26.0 per 1,000 women aged 15-44. There were substantial differences from 10.1 to 42.6 per 1,000 women in the 18 different urban areas. High rate areas had, in comparison with the municipal average, a higher percentage of people with low income, low education, foreign background, and people in need of social welfare. There was also a higher percentage of people living alone and a higher migration rate. Women applying for an induced abortion had similar socio-demographic characteristics. It is concluded that these associations should be considered in future family planning programs and that preventive efforts probably can be made more cost effective by concentrating on areas and individuals with these socio-demographic characteristics.

Abortion Applicants↗
PubMed1992

Purification and characterization of an aminopeptidase from Streptococcus mitis ATCC 903.

An aminopeptidase isolated from the cytoplasmic fraction of a cell extract of Streptococcus mitis ATCC 903 was purified 330-fold by ion-exchange chromatography, gel filtration, and hydroxyapatite chromatography. The partially purified enzyme had a broad substrate specificity. Twelve aminoacyl-beta-naphthylamide substrates were hydrolyzed and also several di-, tri-, tetra-, and pentapeptides and bradykinin. The enzyme hydrolyzed arginine-beta-naphthylamide at the highest rate. Optimal conditions for activity were at pH 7.0-7.2 and at 37-40 degrees C. The molecular weight of the enzyme was estimated to be 93,000. The enzyme was activated by Co2+ ions. Hg2+ inhibited the activity completely. SDS, EDTA, urea, and pCMB also inhibited activity. Inhibition by EDTA could be completely reversed by dialysis and addition of Co2+ ions. Reducing agents, sodium fluoride, and PMSF had no effect on the activity of the enzyme. The isoelectric point of the enzyme was at pH 4.3. High substrate concentrations inhibited activity. Substrate inhibition increased in the presence of high concentrations of Co2+ ions.

Amino Acid Sequence↗
PubMed1992

Interleukin-1 alpha expression is inducible by cholinergic stimulation in the rat adrenal gland.

Interleukin-1-like immunoreactivity has earlier been demonstrated by immunohistochemistry in the noradrenaline-containing chromaffin cells of the rat adrenal gland [Schultzberg et al. (1989) Neuroscience 30, 805-810; Schultzberg et al. (1987) J. Neurosci. Res. 18, 184-189]. In this study, we examine the regulation, upon cholinergic stimulation, of the expression of the cytokine interleukin-1 alpha in the rat adrenal gland. Interleukin-1 alpha and interleukin-1 alpha mRNA levels in the adrenal gland are affected by systemic administration of the cholinergic agonists nicotine (0.5 mg/kg, i.p.) and carbachol (0.5 mg/kg, i.p.). Both drugs cause an increase in interleukin-1 alpha mRNA levels. In contrast to the increased mRNA levels, nicotine and carbachol reduce the interleukin-1 alpha protein level measured in the rat adrenal gland: nicotine by approximately 30%, 60 min after injection, and carbachol by approximately 55%, 30 min after injection. The interleukin-1 alpha protein level returns to control level 90 min after nicotine injection, and 120 min after carbachol injection. We thus found a large, constitutively expressed and inducible pool of interleukin-1 alpha in the rat adrenal gland, which appears to be sensitive to cholinergic stimulation and which may be responsible for some of the local and systemic effects of interleukin-1 alpha. Experiments with Escherichia coli lipopolysaccharide show that this substance, which induces interleukin-1 expression and secretion in macrophages, is also able to induce the expression of interleukin-1 alpha mRNA and interleukin-1 alpha in the adrenal gland when injected at the dose of 2 mg/kg, i.p.

Adrenal Glands↗
PubMed1992

Bioactivation of aflatoxin B1 in the bovine olfactory mucosa: DNA binding, mutagenicity and induction of sister chromatid exchanges.

Nasal olfactory tumours occur in cattle in relatively high frequencies in several developing countries. Since affected animals sometimes show signs of severe aflatoxicosis, a role of aflatoxin B1 (AFB1) in tumorigenesis can be proposed. The results of the present study show that microsomal preparations of the bovine olfactory mucosa have a much higher ability than liver microsomes to induce covalent binding of AFB1 to calf thymus DNA and to microsomal proteins. The major DNA adduct formed was 8,9-dihydro-8-(N7-guanyl)-9-hydroxy-aflatoxin B1. Incubations of microsomal preparations of the bovine nasal olfactory mucosa with glutathione (GSH) and cytosolic fractions of the nasal mucosa resulted in decreased AFB1 DNA binding. A more pronounced decrease was observed when cytosolic fractions of mouse liver were added to the incubations. Mouse liver is known to contain a glutathione-S-transferase with a high ability to scavenge the reactive AFB1-epoxide via conjugation to GSH. Our results indicate that AFB1-GSH conjugation occurs less efficiently in the bovine nasal olfactory mucosa than in the mouse liver. Supernatant preparations (9000 g) of the bovine nasal olfactory mucosa incubated with AFB1 were shown to have the capacity to induce a strong genotoxic response both as regards induction of gene mutations in Salmonella typhimurium TA100 and the induction of sister chromatid exchanges in Chinese hamster ovary cells. Preparations of the bovine liver (9000 g) has a much lower ability to induce these effects. The results of the present study show that the bovine nasal olfactory mucosa has a high AFB1-bioactivating capacity, which can be related to the potent DNA damaging and mutagenic effects observed. It is considered that our results support the assumption that AFB1 plays a role in the aetiology of nasal tumours in cattle.

Aflatoxin B1↗
PubMed1992

Comparative in vitro study of a series of organic nitroesters: unique biphasic concentration-effect curves for glyceryl trinitrate in isolated bovine arterial smooth muscle and lack of stereoselectivity for some glyceryl trinitrate analogues.

Four different organic nitroesters, constituting a homologous series based on unbranched polyalcohols, were compared with regard to in vitro relaxation of isolated bovine mesenteric arteries contracted with 2.5 microM phenylephrine. The organic nitroesters included ethylene glycol dinitrate (EGDN), dinitratopropane (DPN), glyceryl trinitrate (GTN), and tetranitratobutane. Glyceryl trinitrate exhibited a biphasic concentration-effect relationship, with pD2 values of 11.5 +/- 0.5 and 7.2 +/- 0.2 for the high-pD2 and low-pD2 component of the relaxation curve, respectively. The high-pD2 and low-pD2 component contributed 28 and 72% of the maximal response, respectively. EGDN, DPN, and tetranitratobutane induced monophasic concentration-effect curves with pD2 values of 7.4 +/- 0.1, 7.8 +/- 0.2, and 6.9 +/- 0.6, respectively. Stereoisomeric forms of DPN and tetranitratobutane showed no difference with regard to relaxing potency in bovine mesenteric artery. GTN has a partly unique mechanism for vascular smooth muscle relaxation that distinguishes this compound from other related organic nitroesters.

Animals↗
PubMed1992

Immunohistochemical study of 158 lung carcinomas.

Lung carcinomas were studied immunohistochemically and the results were related to type of tissue sample (bronchoscopic biopsies, surgical specimens, autopsies). All cytokeratins (CAM 5.2, PKK-1, AE1/AE3) reacted with virtually all adenocarcinomas, most squamous, and 65% of the large cell carcinomas, while CAM 5.2 was most efficient with the small cell carcinomas. CEA stained 33% and 60% of the small and large cell carcinomas, respectively, most adenocarcinomas, and 84% of the squamous cell carcinomas, among which staining decreased with dedifferentiation and was often focal. EMA reacted with 90%, and NSE with 20% of all histological types. There was no staining for NF. All antibodies, except EMA, were more efficient with surgical specimens. Our study implies that the cytokeratins we used work better with surgical material, but are generally comparable to monospecific cytokeratin antibodies. Also, EMA is a reliable marker for epithelial differentiation with all types of tissue samples. Moreover, CEA negativity in several poorly differentiated lung carcinomas might have implications in the differential diagnosis against pleural mesothelioma.

Carcinoembryonic Antigen↗
PubMed1992

Mononuclear leukocyte ADP-ribosylation as an indicator of immune function in malignant-glioma patients treated with betamethasone for cerebral edema.

Glioma patients receiving corticosteroids (16 mg/day betamethasone) were examined for evidence of immune cell dysfunction by using quantitative estimates of adenosine diphosphate (ADP)-ribosylation in peripheral mononuclear leukocytes as the physiological indicator. The duration of daily treatment with corticosteroids varied from 0 to 35 days at the time of collection of the blood samples. Even after adjustment for covariate factors such as age, sex, smoking habits, alcohol use, antiepileptic medications, and tumor grade, there still remained a highly significant dose-dependent inverse relationship between constitutive and hydrogen peroxide-induced mononuclear leukocyte ADP-ribosylation levels and the duration of corticosteroid treatment (beta coefficients -0.40 and -0.29, respectively; p less than 0.03). No other variable under consideration significantly influenced ADP-ribosylation levels after statistical adjustment. These data support a mutual interdependence of mononuclear leukocyte ADP-ribosylation and corticosteroid-induced immune cell dysfunction in vivo.

Betamethasone↗