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J Johansson

Publications and source records attributed to J Johansson.

At least 19 recordsLinked to original sources
PubMed1992

Secondary structure and orientation of the surfactant protein SP-B in a lipid environment. A Fourier transform infrared spectroscopy study.

Attenuated total reflection Fourier transform infrared spectroscopy was used to investigate the secondary structure of the surfactant protein SP-B. Nearly half of the polypeptide chain is folded in an alpha-helical conformation. No significant change of the secondary structure content was observed when the protein is associated to a lipid bilayer of dipalmitoylphosphatidylcholine (DPPC)/phosphatidylglycerol (PG) or of dipalmitoylphosphatidylglycerol (DPPG). The parameters related to the gamma w(CH2) vibration of the saturated acyl chains reveal no modification of the conformation or orientation of the lipids in the presence of SP-B. A model of orientation of the protein at the lipid/water interface is proposed. In this model, electrostatic interactions between charged residues of SP-B and polar headgroups of PG, and the presence of small hydrophobic alpha-helical peptide stretches slightly inside the bilayers, would maintain SP-B at the membrane surface.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1992

Cysteine reactivity in sorbitol and aldehyde dehydrogenases. Differences towards the pattern in alcohol dehydrogenase.

In sorbitol dehydrogenase only one cysteine residue, Cys-43, is reactive in both anionic buffer (phosphate) and zinc-liganding buffer (imidazole) upon carboxymethylation. This is in contrast to the situation in the structurally related liver alcohol dehydrogenase, with either of two alternative Cys residues being reactive, and is compatible with differences in zinc-binding and active site relationships between these two metalloenzymes. Unrelated aldehyde dehydrogenase, upon carboxamidomethylation, shows a third pattern, now less well defined but confirming the presence of a thiol function of Cys-302 close to the active site.

Alcohol Dehydrogenase↗
PubMed1992

Human surfactant polypeptide SP-B. Disulfide bridges, C-terminal end, and peptide analysis of the airway form.

Human hydrophobic surfactant polypeptide, SP-B, purified from lung tissue by exclusion chromatography in organic solvents, has been characterized. The polypeptide is 79 residues long, has a C-terminal methionine, and contains seven Cys residues. Native human SP-B lacks free thiol groups. Three intrachain disulfide bridges were defined, linking Cys8 to Cys77, Cys11 to Cys71 and Cys35 to Cys46. The remaining Cys48 is concluded to link the protein chains into homodimers via an interchain disulfide to its counterpart in a second SP-B polypeptide. These SS bridges are identical to those in the porcine form and confirm a consestant and unique disulfide pattern for SP-B polypeptides in general.

Amino Acid Sequence↗
PubMed1992

Identification of hydrophobic fragments of alpha 1-antitrypsin and C1 protease inhibitor in human bile, plasma and spleen.

Hydrophobic peptides were isolated from the phospholipid fraction of human bile, plasma and spleen by exclusion chromatography in organic solvents. From plasma, the activation peptide of C1 protease inhibitor was recovered, from spleen the activation peptide of alpha 1-antitrypsin, and from bile, both these peptides, as well as a fragment generated by proteolytic cleavage of alpha 1-antitrypsin six residues N-terminal of the P1-P1' peptide bond. Cleavages in this region inactivate antiproteases but have previously not been reported to occur in vivo. These peptides in human bile may reflect physiological actions in regulation of antiproteolytic activity or bile secretion processes, and/or be of importance for the physicochemical state of cholesterol, phospholipids and bile acids in bile.

Bile↗
PubMed1992

Structure and orientation of the surfactant-associated protein C in a lipid bilayer.

The secondary structure of native and depalmitoylated porcine surfactant-associated protein C (SP-C) was studied by attenuated total reflection Fourier-transform infrared spectroscopy. Both forms of porcine SP-C adopt mainly an alpha-helical conformation. These two forms of the protein were reconstituted in a lipid bilayer. The insertion of the protein in a membrane is associated with an increase of the alpha-helical content. Dichroic measurements show that, in both cases, the long axis of the alpha-helix is oriented parallel to the lipid acyl chains.

Animals↗
PubMed1992

Splenic primary sensory afferents in the guinea pig demonstrated with anterogradely transported wheat-germ agglutinin conjugated to horseradish peroxidase.

The distribution of primary visceral afferents to the spleen of the guinea pig was studied after injections of wheat-germ agglutinin conjugated to horseradish peroxidase (HRP) into the left dorsal root ganglia at levels T7-T12. After anterograde transport of the tracer, labeled fibers were found in the nerves around the splenic artery in the hilus region and in the splenic parenchyma. The majority of labeled fibers in the spleen were detected in the white pulp. HRP-positive fibers were also observed in the red pulp and in the trabeculae. The distribution of the HRP-labeled fibers was in part similar to those of substance P-immunoreactive and calcitonin gene-related peptide-immunoreactive nerve structures. The results show that the anterograde tracing technique can be used successfully to investigate splenic primary afferent innervation.

Afferent Pathways↗
PubMed1992

Close correlation between high-density lipoprotein and triglycerides in normotriglyceridaemia.

The relationship between high-density-lipoprotein (HDL) particle size subclasses and the levels of the major lipoprotein lipids was studied in 74 men consecutively referred to the lipid clinic. HDL (density 1.070-1.21 kg l-1) was separated by polyacrylamide gradient gel electrophoresis (GGE) into five size-defined subclasses, in order of decreasing size as follows: HDL2b, HDL2a, HDL3a, HDL3b and HDL3c. Cholesterol and triglyceride concentrations in very-low-density (VLDL), low-density (LDL) and high-density (HDL) lipoproteins were determined. The level of VLDL triglycerides was negatively correlated with HDL2b (r = -0.66, P less than 0.0001), and positively correlated with HDL3b concentrations (r = 0.65, P less than 0.0001). Both correlations were restricted to subjects with VLDL triglyceride concentrations of less than 1.80 mmol l-1, i.e. those with normotriglyceridaemia. Patients with a history of myocardial infarction and/or angina pectoris (n = 18) had significantly lower HDL2b levels than subjects with asymptomatic hyperlipidaemia (n = 50), i.e. 0.16 vs. 0.22 mg protein ml-1 (P less than 0.05), despite essentially similar cholesterol and triglyceride levels in the VLDL, LDL and HDL fractions, including HDL2 and HDL3 cholesterol.

Adult↗
PubMed1992

Correlation between computer-assisted femoral arteriography and physiological tests in hypercholesterolaemic patients: a methodological study with special reference to clinical trials.

The validity of computer-assisted femoral arteriography, for the study of regression/progression of atherosclerosis in follow-up clinical trials, was investigated by comparison with routine physiological estimates of peripheral circulatory function. Thus, in 114 hypercholesterolaemic patients, the results of aorto-femoral arteriography were compared with those of leg segmental blood pressure measurement, oscillometry, digital pulse plethysmography, and bicycle and treadmill exercise tests. In 107 patients, 18 with symptoms of peripheral vascular disease (PVD) and 89 asymptomatic, magnification arteriograms of a 20 cm segment of the right or left superficial femoral artery were obtained. These arteriograms were digitized and the following variables were calculated: arterial lumen volume (corrected for body size), per cent stenosis, and edge roughness. The correlation between arteriographic and physiological variables was investigated with a linear regression model, taking into account the possible interaction with sex, and presence or absence of symptoms of PVD. Lumen volume correlated significantly with all five physiological variables, and per cent stenosis correlated significantly with four of the physiological variables. For the roughness measure, however a significant correlation was found only with plethysmography. By using logistic multiple regression analysis linear functions of physiological variables were constructed to detect ilio-femoral arterial occlusion. The sensitivity/specificity for detection of right-sided, left-sided, and bilateral occlusion was 0.83/0.98, 0.78/0.98, and 0.60/1.00 respectively (N = 108-111). Systolic blood pressure (ankle-arm ratio) was the single variable most closely correlated to the likelihood of arterial occlusions. It is concluded that arterial lumen volume and per cent stenosis, measured for the digitized femoral arteriogram, correlate well with physiological variables, which reflect the state of atherosclerosis both in the femoral arteries and in other arterial beds including the heart, and that routine physiological tests can be used to identify patients with arterial occlusions in the iliac and femoral arteries.

Adult↗
PubMed1991

Surfactant protein B: disulfide bridges, structural properties, and kringle similarities.

The disulfide bridges in porcine hydrophobic surfactant protein B (SP-B) were determined. Results show that three intrachain bridges link half-cystine residues 8 and 77, 11 and 71, and 35 and 46, respectively. This gives SP-B an appearance of three loops, a central big loop surrounded by two smaller ones. In the major form of SP-B, the remaining half-cystine, Cys-48, is probably interchain-linked to its counterpart in another molecule, compatible with the existence of dimeric molecules. A minor fraction, with monomeric SP-B but also lacking free thiols, could be due to polypeptides having Cys-57 (instead of Leu in the major form) and hence an additional intrachain bond (Cys-48-Cys-57). Notably, one of the three intrachain bonds common to all SP-B molecules is analogous to one of the disulfide linkages in the kringle structure of complex serine proteases. SP-B and kringles are also similar in size and in positions of half-cystine residues. SP-B and the kringle of coagulation factor XII exhibit 26% residue identity. This structural similarity of SP-B to a binding domain could reflect functional homology, compatible with the notion that SP-B interacts with surfactant anionic phospholipids, which is also in agreement with an SP-B excess of basic residues. Finally, weak similarities between the perform of SP-B and complex serine proteases are also found. This has implications on further possible relationships between kringles, serine proteases, and antiproteases.

Amino Acid Sequence↗
PubMed1991

Canine hydrophobic surfactant polypeptide SP-C. A lipopeptide with one thioester-linked palmitoyl group.

The amino acid sequence and the posttranslational modification of the hydrophobic surfactant polypeptide SP-C from canine, rabbit and bovine lungs were established by direct sequence analysis and plasma-desorption time-of-flight mass spectrometry. The results reveal that canine SP-C has only one cysteine residue which, however, is palmitoylated, like the two Cys residues in other characterized SP-C molecules. In addition, canine SP-C is N-terminally truncated, with only 34 amino acid residues in its longest form. Thus, SP-C molecules can apparently vary to some extent in the N-terminal lipid-modified part, whereas the extremely hydrophobic middle and C-terminal parts are well conserved.

Amino Acid Sequence↗
PubMed1991

Closely related isozymes of alcohol dehydrogenase. Carboxymethylation: gamma 1 gamma 1 differs widely from both beta 1 beta 1 and its equine equivalence EE.

Human gamma 1 gamma 1 alcohol dehydrogenase is quite insensitive to inactivation by iodoacetate, its equine counterpart EE highly sensitive, and the human beta 1 beta 1 form intermediately sensitive. Imidazole hardly influences the iodoacetate inactivation of gamma 1 gamma 1, enhances that of EE and decreases that of beta 1 beta 1. In all isozymes, metal-binding Cys residues are the most reactive, but the patterns for those binding the active site zinc atom differ. In phosphate, Cys-46 is most sensitive in EE and gamma 1 gamma 1, Cys-174 in beta 1 beta 1. This difference appears to correlate with the absence or presence, respectively, of an extra methyl group in the side-chain at position 48 (Ser in EE and gamma 1 gamma 1, Thr in beta 1 beta 1). In imidazole, the reactivity in beta 1 beta 1 is shifted to Cys-46, while the specificity is enhanced in EE and decreased in gamma 1 gamma 1. Thus, the inactivations illustrate large differences among structures closely related.

Alcohol Dehydrogenase↗
PubMed1991

Plasma high density lipoprotein particle size alteration by simvastatin treatment in patients with hypercholesterolaemia.

Twenty-two patients with pronounced hypercholesterolaemia were treated with simvastatin in increasing doses, i.e. 10, 20 and 40 mg O.D. Each treatment regimen had a duration of 6 weeks. In addition to the expected low density lipoprotein (LDL)-lowering effect, simvastatin altered the plasma HDL particle size spectrum by selective elevation of the plasma HDL2b and HDL3a levels, as defined by polyacrylamide gradient gel electrophoresis (gge). While the reduction in LDL cholesterol by simvastatin was dose dependent, the effect on HDL was maximal already at 10 mg daily. On treatment with simvastatin 10 mg O.D., the plasma HDL2b and HDL3a concentrations increased by 30% (P less than 0.001) and 12% (P less than 0.01) respectively. On the corresponding treatment with simvastatin LDL cholesterol decreased by 31% (P less than 0.001). The very low density lipoprotein (VLDL) cholesterol to triglyceride ratio was significantly lowered by treatment with 10 mg simvastatin O.D. suggesting a compositional change in VLDL. Positive univariate correlations between treatment-induced decreases in plasma HDL3b/3c levels and VLDL triglyceride concentration were seen. It is suggested that inhibition of cholesterol synthesis in hypercholesterolaemic subjects by simvastatin treatment alters the composition of VLDL, which may affect the close relation between HDL and VLDL, in turn producing selective elevations of the plasma HDL2b and HDL3a levels.

Adult↗
PubMed1991

The association of lipoprotein and hepatic lipase activities with high density lipoprotein subclass levels in men with myocardial infarction at a young age.

The relations between postheparin plasma lipase activities and concentrations of lipoproteins, in particular plasma high density lipoprotein (HDL) subclasses determined by gradient gel electrophoresis, were examined in 39 men who had survived a first myocardial infarction before the age of 45 years and in 20 age-matched control men. Reduced lipoprotein lipase (LPL) and hepatic lipase (HL) activities were found in the patients due to low LPL activity in patients with hypertriglyceridaemia, and low HL activity in those with a normal lipoprotein pattern or hypercholesterolaemia. Considerably lower plasma HDL2b and HDL2a protein concentrations and higher plasma HDL3b and HDL3c protein levels were found in the patients compared with the healthy control subjects. The subgroup of patients with hypertriglyceridaemia accounted for the major proportion of the case control differences for the HDL subspecies. However, significantly lower HDL2b and HDL2a concentrations were seen also among the normotriglyceridaemic patients. Analysis of the correlations between concentrations of HDL subclasses and lipase activities revealed positive associations between LPL and HDL2b and negative associations between HL and HDL2b. For LPL, this relationship was confined to hypertriglyceridaemic and for HL to normotriglyceridaemic subjects. HL was indicated to be positively connected with HDL3b levels, irrespective of lipoprotein pattern, whereas LPL seemed to be unassociated with HDL3b. It is concluded that low LPL and HL activities partly account for the change in HDL subclass distribution observed in patients with myocardial infarction at a young age.

Adult↗
PubMed1991

Persistence of serum antibodies elicited by Haemophilus influenzae type b-tetanus toxoid conjugate vaccine in infants vaccinated at 3, 5 and 12 months of age.

Eighty-five children received three injections of a vaccine consisting of Haemophilus influenzae type b (Hib) capsular polysaccharide (CPS) conjugated to tetanus toxoid (TT) (Hib-TT) at 3, 5 and 12 months of age according to the vaccination schedule for Swedish children. Diphtheria-tetanus toxoid vaccine was concurrently injected at another site. Two dosages, 7.5 and 15 micrograms, of Hib CPS were studied. No serious reactions occurred. Hib-TT elicited fewer local reactions than diphtheria-tetanus toxoid vaccine. Significant increases in Hib CPS serum antibodies occurred after all injections in both dosage groups with virtually no differences between the two groups. After the first and second injections geometric mean serum antibody concentrations of both dosage groups combined increased to 0.49 and 3.71 micrograms/ml and 81 and 99% of the vaccinees, respectively, had concentrations greater than 0.15 micrograms/ml. After the third dose geometric mean concentrations increased to 13.7 micrograms/ml and all had concentrations greater than 0.15 micrograms/ml. The geometric mean Hib CPS antibody concentrations decreased to 1.24 micrograms/ml 18 months after the third injection, but 97% still had concentrations greater than 0.15 micrograms/ml. The rise of Hib CPS antibodies was mostly in the IgG class. The most pronounced increase was seen in the IgG1 subclass but there were also increase in IgG2 and IgG3. Protective concentrations of TT antibodies were found in all postimmunization sera. In conclusion Hib-TT is safe and immunogenic in infants and should be protective from 6 to 30 months and probably longer thereafter.

Antibodies, Bacterial↗
PubMed1991

Fluorescence imaging and point measurements of tissue: applications to the demarcation of malignant tumors and atherosclerotic lesions from normal tissue.

The possibilities of using laser-induced fluorescence for tissue diagnostics are discussed. The tissue types investigated are malignant tumors and atherosclerotic lesions. Studies with natural autofluorescence as well as with fluorescent tumor markers are included in this paper. Fluorescence emission and decay data are presented for some tissue chromophores contributing to tissue autofluorescence. Optical spectroscopic characteristics of fluorescent malignant tumor markers are analyzed and instrumental designs for clinical applications are discussed. Images recorded with a multicolor fluorescence imaging system developed in Lund are presented.

Adenocarcinoma↗
PubMed1991

Atherosclerosis-related measures in digitized femoral arteriograms.

Atherosclerosis is reflected in the arteriogram as narrowing of the arterial lumen and irregularity of the arterial wall. We have quantified these changes in digitized femoral arteriograms from 107 hypercholesterolaemic patients and defined 10 different measures concerning arterial diameter, cross-sectional area, stenosis and edge irregularity. We examined the precision of these measures and the correlations between them. Lumen volume and mean diameter for defined arterial segments had the highest precision and may be useful for follow-up studies. The linear correlation between the mean diameter and the square root of the lumen volume was greater than 0.99, so these two measures seem to be equivalent for all practical purposes. The measured variables could be separated into 2 groups: the measures concerning arterial diameter and lumen volume and those concerning edge irregularity and localized stenosis. The measures within each group showed strong positive mutual correlations, while the correlations between measures from different groups were negative and small. It was concluded that if the results of one measure from each group, suitably those of lumen volume and edge roughness, are known, the other described measures will add no further information about the atherosclerotic process.

Arteriosclerosis↗