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H Karlsson

Publications and source records attributed to H Karlsson.

At least 91 records · Page 5Linked to original sources
PubMed1993

Contact Nd:YAG laser and regional renal hypothermia in partial nephrectomy.

Contact Nd:YAG laser resection using the sapphire tip is nowadays a well-known method of partial nephrectomy. Our material consists of six patients (seven resections). The indication for the operation was a renal carcinoma in five patients (six resections) and renal changes of von Hippel-Lindau syndrome in one patient. Occlusion of the renal artery insured a good intraoperative haemostasis. This improved the cutting properties of the laser and made it more accurate. Low energy levels could be used. Thus the destruction of the renal parenchyma will be reduced. The mean follow-up time was 15.3 months. No local recurrences or distant metastases have been detected. In our hands the Nd:YAG contact laser combined with renal hypothermia is superior to traditional methods of partial nephrectomy.

Carcinoma, Renal Cell↗
PubMed1992

The blood group B type-4 heptaglycosylceramide is a minor blood group B structure in human B kidneys in contrast to the corresponding A type-4 compound in A kidneys. Structural and in vitro biosynthetic studies.

Blood group A glycolipid antigens have been found based upon at least four different core saccharides (types 1 to 4). The biological significance of this structural polymorphism is not known, although the successful outcome of transplantations of blood group A2 kidneys to blood group O individuals have been partly explained by the low expression of A type-3 and -4 chain glycolipid antigens in A2 kidneys. If graft rejection due to ABO incompatibility is, in any way, correlated to the expression of type-3 and -4 chain blood group glycolipids, it is of interest to identify possible blood group B structures based on these core saccharides. In a non-acid glycosphingolipid fraction isolated from human blood group B kidneys, mass spectrometry, high-temperature gas chromatography-mass spectrometry and probing of thin-layer chromatograms with Gal alpha 1-4Gal-specific Escherichia coli and monoclonal anti-B antibodies provided evidence for minute amounts of a Gal alpha 1-3(Fuc alpha 1-2)Gal beta-HexNAc-Gal alpha 1-4Gal beta-Hex-Ceramide structure consistent with a B type-4 chain heptaglycosylceramide. In contrast, blood group A kidneys have the corresponding A type-4 chain heptaglycosylceramide as the predominant blood group A glycolipid. No, or very low activity of the blood group B gene enzyme on the type-4 chain blood group H hexaglycosylceramide precursor was found by biosynthetic experiments in vitro, which might explain the low expression of type-4 chain blood group B heptaglycosylceramides in human blood group B kidneys.

ABO Blood-Group System↗
PubMed1992

In vitro metabolic inhibition of the human lymphocyte: influence on the expression of interleukin-2 receptors.

We have investigated the effects of energy depletion in human lymphocytes on the expression of the membrane-bound interleukin-2 receptor (IL-2R) and the release of soluble IL-2R. Concanavalin-A (Con-A) and IL-2-transformed lymphocytes were incubated with sodium fluoride, inhibiting the Embden-Meyerhof pathway, rotenone and 2,4-dinitrophenol (2,4-DNP), which are known to disturb mitochondrial high energy production. Rotenone was found to be the most potent inhibitor, with a half maximal effect at 10 nmol/L. 2,4-DNP and sodium fluoride, although not as potent as rotenone, showed marked inhibitory effects in higher concentrations, with half maximal effects at 50 mumol/L and 5 mmol/L respectively. No difference in the inhibition pattern for membrane-bound IL-2R compared with sIL-2R was observed. It is concluded that intracellular synthesis, transport and subsequent membrane insertion or release of receptors important for immunoregulation require high energy phosphate compounds and are sensitive to disturbances in intracellular energy levels.

2,4-Dinitrophenol↗
PubMed1991

Analysis of sialic acid-containing mucin oligosaccharides from porcine small intestine by high-temperature gas chromatography-mass spectrometry of their dimethylamides.

Acetylation of sialic acid-containing oligosaccharides lactonises the sialic acid residue quantitatively for all oligosaccharides studied except for 6'-sialyl-lactose. The modified, unsulphated, sialylated and sulphated oligosaccharides can then be fractionated by anion-exchange chromatography. Ammonolysis of the lactones followed by methylation yielded the dimethylamides, which are amenable to g.l.c.-m.s. and give intense and informative mass spectra. This approach has been used to characterise the sialic acid-containing O-linked oligosaccharides obtained from the mucin glycopeptides of the small intestine of the pig. At least 28 structures were found, having NeuAc or NeuGc 6-linked to the HexNAc attached to the peptide core or to a Hex 3-linked to HexNAc. Four different disialylated oligosaccharides were found having NeuAc or NeuGc on the Hex residue 3-linked to HexNAc and 6-linked to HexNAc.

Animals↗
PubMed1991

The immunosuppressive agent FK506 inhibits in vitro expression of membrane-bound and soluble interleukin-2 receptors on resting but not on activated human lymphocytes.

FK506 is a recently introduced immunosuppressive agent synthesised by the microorganism Streptomyces tskubaensis. It has been found to be more potent than Cyclosporin A in inhibiting T cell activation. We investigated its effects on the expression of membrane bound as well as soluble interleukin-2 receptors on human lymphocytes. The membrane-bound IL-2 receptor expression was inhibited by FK506 in resting lymphocytes at a concentration of 1 pmol/l. At 10 nmol/l no further inhibition was seen. In activated lymphocytes FK506 exerted no inhibitory effect on the IL-2 receptor expression. The release of soluble IL-2 receptor showed a pronounced decline in the concentration interval between 10 pmol/l and 0.1 nmol/l. Above a concentration of 10 nmol/l, no further decrease was seen. In activated lymphocytes the expression of soluble IL-2 receptors was unaffected by FK506 incubated up to 72 h. Pretreatment of the lymphocytes with the compound did not further depress the expression of the membrane-bound or the soluble receptor. Our results also indicate that the expression of the membrane-bound receptor is more sensitive to the drug than the soluble form of the receptor.

Enzyme-Linked Immunosorbent Assay↗
PubMed1991

FK506 lacks the ability to inhibit expression of interleukin-2 receptor beta-chain on human lymphocytes.

Proliferation of T-lymphocytes is induced by interleukin-2 binding to the interleukin-2 receptor. This receptor consists of an alpha and a beta chain. FK506 is a new immunosuppressant known to inhibit synthesis of interleukin 2 and expression of the membrane bound alpha chain. In this study we show that FK506 does not suppress the expression of the beta chain on human lymphocytes, in the concentration range 1 pM to 1 microM, as measured by flow cytometry.

Cells, Cultured↗
PubMed1990

Transient expression of type 2 chain in A-active hexaglycosylceramide of rat small intestine at weaning time. Demonstration by affinity chromatography and ceramide glycanase hydrolysis of A-active glycosphingolipids followed by gas chromatography and mass spectrometry of permethylated hexasaccharides.

The small intestine of 15- to 23-day-old rats was cut into four segments from the duodenum to the ileum. Neutral glycosphingolipids were purified from each segment and submitted to thin-layer chromatography and immunostaining with the A005 monoclonal anti-A antibody. This antibody detected an hexaglycosylceramide located mainly in the duodenum during the postnatal development. In order to characterize hexaglycosylceramides, blood group A-active glycolipids were purified by affinity chromatography on immobilized Helix pomatia lectin in organic solvent. Hexaglycosylceramides (A-6) were subsequently isolated by preparative thin-layer chromatography and hydrolyzed with ceramide glycanase. The free hexasaccharides were permethylated and analyzed by gas chromatography. Two peaks were detected in varying ratios during development, corresponding to type 1 and type 2 chain A hexasaccharides. Gas chromatography clearly demonstrated that type 2 A-6 occurred in the duodenum of developing rats, and that a shift from type 2 to type 1 A-6 occurred with growing age. The change from type 2 to type 1 chain was also assessed by methylation analysis, and by the variation of the characteristic fragmentations of type 1 and type 2 chain hexasaccharides upon mass spectometry of the permethylated A-6 oligosaccharides from the duodenum of 19-day-old and adult rats.

Aging↗
PubMed1990

Microdialysis in the human brain: extracellular measurements in the thalamus of parkinsonian patients.

Microdialysis in the human brain has been performed for the first time during thalamotomy intended to relieve tremor in patients with Parkinson's disease. The aim was to test the reliability of the microdialysis technique for biochemical characterization of a target area in the human brain during a routine operation. Microdialysis probes were introduced through the same trajectory as the lesioning electrode thus causing no additional damage to the brain. Dopamine, DOPAC, HVA, 5-HIAA, hypoxanthine, inosine, guanosine, adenosine, GABA, taurine, aspartate and glutamate were measured in the perfusate from the target region - the Vim nucleus. The results show initial high levels that reach baseline levels after 10-20 minutes. Surprisingly, consistent and reproducible levels were found, the only exception being one patient on 1-DOPA therapy who had elevated DA and metabolite levels.

Aged↗
PubMed1989

The use of gas chromatography and gas chromatography-mass spectrometry for the characterization of permethylated oligosaccharides with molecular mass up to 2300.

Gas chromatography and gas chromatography-mass spectrometry were adapted for the analysis of large permethylated oligosaccharides of different types. Permethylated isomaltooligosaccharides with up to 11 sugar residues and a mass of 2291 Da and two branched blood group H-type decasaccharides derived from the corresponding glycosphingolipids with masses of 2150 Da were successfully analyzed. The capillary columns used have extremely good resolution exemplified by the separation of the two decasaccharides which only differed by one internal linkage position and by the separation of four isomeric tetrasaccharides. The combined information of retention times and mass spectra gave detailed information of 22 neutral oligosaccharides from porcine intestinal mucin and the approach thus allow quick screening of O-linked-type glycans. The procedure for permethylation of oligosaccharides using solid NaOH has been investigated and adapted for structures having a glucose alditol as in reduced oligosaccharides derived from milk and glycosphingolipids.

Animals↗
PubMed1989

Characterization of glycosphingolipid mixtures with up to ten sugars by gas chromatography and gas chromatography-mass spectrometry as permethylated oligosaccharides and ceramides released by ceramide glycanase.

A novel, effective method for structural characterization of glycosphingolipids has been devised. It employs ceramide glycanase to release intact oligosaccharides followed by analysis using high-mass gas chromatography-mass spectrometry. The oligosaccharides and ceramides released by the glycanase were permethylated and analyzed. The capillary gas chromatography gave excellent resolution and separated, for example, two isomeric 10-sugar oligosaccharides with a molecular mass of 2150 daltons differing only by a Gal1-3GlcNAc and a Gal1-4GlcNAc linkage. The oligosaccharides released from sialic acid containing glycosphingolipids (gangliosides) were also analyzed for monosialo compounds. This analytical approach is simple, is quick, and can readily allow quantitation of individual glycosphingolipids.

Ceramides↗
PubMed1989

Novel isoglobo-neolacto-series hybrid glycolipid detected by a monoclonal antibody is a rat colon tumor-associated antigen.

Isoglobotetraosylceramide (GalNAc(beta 1-3)Gal(alpha 1-3)Gal(beta 1-4)Glc (beta 1-1)Cer), the major glycolipid species in dimethylhydrazine-induced rat tumors of colorectal origin, was not detected in epithelial cells of normal colon but was present in the non-epithelial stroma and could be extracted from each of nine tumors studied. Monoclonal antibodies produced against isoglobotetraosylceramide detected this and another novel rat tumor-associated glycolipid not present in epithelial cells nor in non-epithelial stroma of normal rat colon (Brodin, T., Thurin, J., Strömberg, N., Karlsson, K.-A. and Sjögren, H.O. (1985) Eur. J. Immunol. 16, 951-956). This novel glycolipid was present in 8/9 of the studied tumors and was also present in two in vitro cell clones. These were originally obtained from a W49/T4 colon tumor isograft. The novel glycolipid was characterized by mass spectrometry, 1H-NMR, and methylation analysis as a hybrid between the isoglobo- and neolacto-series, with the structure GalNAc(beta 1-3)Gal(alpha 1-3)Gal(beta 1-4)GlcNA(beta 1-3)Gal (beta 1-4)Glc(beta 1-1)Cer.

Animals↗
PubMed1988

Structures of the eight- to nine-sugar glycolipids of human blood group A erythrocytes.

Two glycolipid fractions, isolated in 1975 from blood group A1 erythrocytes and shown on the basis of direct-inlet mass spectrometry to contain eight- and nine-sugar A-type sequences, have been reinvestigated by fast-atom-bombardment mass spectrometry and overlay analysis with selected monoclonal anti-A antibodies. The presence of three separate glycolipids was concluded, consistent with a common paragloboside backbone [beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-D-Glc] and a typical erythrocyte ceramide component (sphingosine, and 22-, 23-, 24-, and 25-carbon nonhydroxy fatty acids). It is proposed that they carry A determinants based on Type 1 [beta-D-Galp-(1----3)-beta-D-GlcpNAc], Type 2 [beta-D-Galp-(1----4)-beta-D-GlcpNAc], and Type 3 [beta-D-Galp-(1----3)-alpha-D-GalpNAc] chains, respectively. The Type 1 (eight sugars) and Type 3 (nine sugars) glycolipids appeared in mixtures of both the native and the acetylated form. The existence of Type 1 glycolipid, which appears to be a genuine erythrocyte glycolipid as concluded from the ceramide composition, had been predicted earlier by other workers.

ABO Blood-Group System↗
PubMed1988

Analysis of the traction forces in different skull traction systems.

During transportation of patients under skull traction, swinging of the weights produces acceleration forces that not only can cause pain and discomfort for the patient, but also can cause worsening of the cervical fracture or dislocation. Skull traction systems also involve friction forces. In a system with one pulley, the friction forces were 10 to 21.5% of the weight applied but, in a system with three pulleys (Stryker SurgiBed 965), they were as much as 65%. A new spring traction device that permits traction during transportation showed better physical characteristics than the hanging weight systems.

Beds↗
PubMed1987

Rapid characterization of mucin oligosaccharides from rat small intestine with gas chromatography-mass spectrometry.

Mucin glycopeptides were isolated from rat small intestinal mucosa after reduction/alkylation, trypsin digestion and gel chromatography. The oligosaccharides were released by using alkaline-NaBH4, separated into neutral and acidic species and permethylated. The derivatized mixtures were analysed with fast atom bombardment mass spectrometry and gas chromatography-mass spectrometry using thin film columns. Permethylated neutral oligosaccharides with up to seven sugars could be chromatographed and detected with mass spectrometry. The complex mixture revealed was partly due to the linkage GalNAc being substituted at both position 3 and 6. The approach will be very useful when analysing small amounts of mucins and mucin fragments.

Animals↗