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Biomedical subjects

M Månsson

Publications and source records attributed to M Månsson.

17 recordsLinked to original sources

Angle resolved photoemission from Nd1.85Ce0.15CuO4 using high energy photons: a fermi surface investigation.

We have performed an angle resolved photoemission study on a single crystal of the optimally electron doped (n-type) cuprate superconductor Nd2-xCexCuO4 (x=0.15) at a photon energy of 400 eV. The Fermi surface is mapped out and is, in agreement with earlier measurements, of hole-type with the expected Luttinger volume. However, comparing with previous low energy measurements, we observe a different Fermi surface shape and a different distribution of spectral intensity around the Fermi surface contour. The observed Fermi surface shape indicates a stronger electron correlation in the bulk as compared to the surface.

Journal Article↗

A rapid and sensitive procedure for determination of 5-N-acetyl neuraminic acid in lipopolysaccharides of Haemophilus influenzae: a survey of 24 non-typeable H. influenzae strains.

In view of the importance of 5-N-acetyl neuraminic acid in bacterial pathogenesis, a sensitive, reproducible and reliable method for the determination of 5-N-acetyl neuraminic acid levels in lipopolysaccharide (LPS) is described and applied to 24 different non-typeable Haemophilus influenzae (NTHi) strains. The method involves analysis by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) of terminal 5-N-acetyl neuraminic acid residues released by neuraminidase treatment of O-deacylated LPS. The procedure is relatively fast and the instrumental effort is moderate. The results of the procedure were compared with data obtained by 1H NMR and electrospray ionisation-mass spectrometry (ESI-MS). The analysis of LPS from 24 NTHi strains showed that 5-N-acetyl neuraminic acid was found to be a common constituent of LPS in NTHi. Only one strain (NTHi 432) did not show any sialylation. Molar ratios (LPS/5-N-acetyl neuraminic acid) ranged between 5/1 and 500/1. Several strains in which no 5-N-acetyl neuraminic acid could be determined by other methods including 1H NMR and ESI-MS were shown to contain 5-N-acetyl neuraminic acid by this HPAEC-PAD procedure. The method was applied to determine levels of terminal 5-N-acetyl neuraminic acid in LPS from NTHi strains grown under different conditions and mutant strains containing inactive LPS biosynthetic genes.

Chromatography, Ion Exchange↗

Cardiotocography only versus cardiotocography plus ST analysis of fetal electrocardiogram for intrapartum fetal monitoring: a Swedish randomised controlled trial.

BACKGROUND: Previous studies indicate that analysis of the ST waveform of the fetal electrocardiogram provides information on the fetal response to hypoxia. We did a multicentre randomised controlled trial to test the hypothesis that intrapartum monitoring with cardiotocography combined with automatic ST-waveform analysis results in an improved perinatal outcome compared with cardiotocography alone. METHODS: At three Swedish labour wards, 4966 women with term fetuses in the cephalic presentation entered the trial during labour after a clinical decision had been made to apply a fetal scalp electrode for internal cardiotocography. They were randomly assigned monitoring with cardiotocography plus ST analysis (CTG+ST group) or cardiotocography only (CTG group). The main outcome measure was rate of umbilical-artery metabolic acidosis (pH <7.05 and base deficit >12 mmol/L). Secondary outcomes included operative delivery for fetal distress. Results were first analysed according to intention to treat, and secondly after exclusion of cases with severe malformations or with inadequate monitoring. FINDINGS: The CTG+ST group showed significantly lower rates of umbilical-artery metabolic acidosis than the cardiotocography group (15 of 2159 [0.7%] vs 31 of 2079 [2%], relative risk 0.47 [95% CI 0.25-0.86], p=0.02) and of operative delivery for fetal distress (193 of 2519 [8%] vs 227 of 2447 [9%], 0.83 [0.69-0.99], p=0.047) when all cases were included according to intention to treat. The differences were more pronounced after exclusion of 291 in the CTG+ST group and 283 in the CTG group with malformations or inadequate recording. INTERPRETATION: Intrapartum monitoring with cardiotocography combined with automatic ST-waveform analysis increases the ability of obstetricians to identify fetal hypoxia and to intervene more appropriately, resulting in an improved perinatal outcome.

Acidosis↗

Identification of a lipopolysaccharide alpha-2,3-sialyltransferase from Haemophilus influenzae.

We have identified a gene for the addition of N-acetylneuraminic acid (Neu5Ac) in an alpha-2,3-linkage to a lactosyl acceptor moiety of the lipopolysaccharide (LPS) of the human pathogen Haemophilus influenzae. The gene is one that was identified previously as a phase-variable gene known as lic3A. Extracts of H. influenzae, as well as recombinant Escherichia coli strains producing Lic3A, demonstrate sialyltransferase activity in assays using synthetic fluorescent acceptors with a terminal galactosyl, lactosyl or N-acetyl-lactosaminyl moiety. In the RM118 strain of H. influenzae, Lic3A activity is modulated by the action of another phase-variable glycosyltransferase, LgtC, which competes for the same lactosyl acceptor moiety. Structural analysis of LPS from a RM118:lgtC mutant and the non-typeable strain 486 using mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy confirmed that the major sialylated species has a sialyl-alpha-(2-3)-lactosyl extension off the distal heptose. This sialylated glycoform was absent in strains containing a lic3A gene disruption. Low amounts of sialylated higher molecular mass glycoforms were present in RM118:lgtC lic3A, indicating the presence of a second sialyltransferase. Lic3A mutants of H. influenzae strains show reduced resistance to the killing effects of normal human serum. Lic3A, encoding an alpha-2,3-sialyltransferase activity, is the first reported phase-variable sialyltransferase gene.

Blood Bactericidal Activity↗

A new structural type for Haemophilus influenzae lipopolysaccharide. Structural analysis of the lipopolysaccharide from nontypeable Haemophilus influenzae strain 486.

Structural elucidation of the sialylated lipopolysaccharide (LPS) of non-typeable Haemophilus influenzae (NTHi) strain 486 has been achieved by the application of high-field NMR techniques and ESI-MS along with composition and linkage analyses on O-deacylated LPS and oligosaccharide samples. It was found that the LPS contains the common element of H. influenzae, L-alpha-D-Hepp-(1-->2)-[PEtn-->6]-L-alpha-D-Hepp-(1-->3)-[beta-D-Glcp-(1-->4)]-L-alpha-D-Hepp-(1-->5)-[PPEtn-->4]-alpha-Kdop-(2-->6)-Lipid A, but instead of glycosyl substitution of the terminal heptose residue (HepIII) at the O2 position observed in other H. influenzae strains, HepIII is chain elongated at the O3 position by either lactose or sialyllactose (i.e. alpha-Neu5Ac-(2-->3)-beta-D-Galp-(1-->4)-beta-D-Glcp). The LPS is substituted by an O-acetyl group linked to the O2 position of HepIII and phosphocholine (PCho) which was located at the O6 position of a terminal alpha-D-Glcp residue attached to the central heptose, a molecular environment different from what has been reported earlier for PCho. In addition, minor substitution by O-linked glycine to the LPS was observed. By investigation of LPS from a lpsA mutant of NTHi strain 486, it was demonstrated that the lpsA gene product also is responsible for chain extension from HepIII in this strain. The involvement of lic1 in expression of PCho was established by investigation of a lic1 mutant of NTHi strain 486.

Carbohydrate Conformation↗

Glycine is a common substituent of the inner core in Haemophilus influenzae lipopolysaccharide.

A survey of both typeable and nontypeable strains of Haemophilus influenzae indicated that they contain glycine (Gly) in their lipopolysaccharide (LPS). Significant amounts (30-250 pmol Gly/microg LPS) were determined by high-performance anion-exchange chromatography using pulsed amperometric detection after treatment of the LPS with mild alkali. Oligosaccharides obtained from LPS after mild acid hydrolysis and gel filtration chromatography were investigated by electrospray ionization mass spectrometry (ESI-MS) and capillary electrophoresis (CE) ESI-MS. In all cases, molecular ions corresponding to the major glycoforms were identified and were accompanied by ions differing by 57 Da, thus indicating the presence of glycine. The position of glycine in these glycoforms was determined by CE-ESI-MS/MS analyses. It was found that, depending on strain, glycine can substitute each of the heptoses of the inner-core element, L-alpha-D-Hepp-(1-->2)-[PEtn-->6]-L-alpha-D-Hepp-(1-->3)-L-alpha-D-Hepp-(1-->5)-alpha-Kdo of H. influenzae LPS as well as Kdo. In some strains, mixtures of monosubstituted Gly-containing glycoforms having different substitution patterns were identified.

Acetylation↗

[Insufficient legal rights of traffic accident victims. Insurance companies should force more active compensation claims].

According to law, persons injured in road traffic accidents are entitled to compensation. In almost 92% of cases, victims accept a modified solution suggested by the insurance company involved. If an agreement cannot be reached, or the disability is 10% or more, the case is referred to The Road Traffic Injuries Commission (TSN). Insurance companies often claim that the lengthy wait for a final ruling--up to four years or more--is due to the lack of a doctor's certificate of disability.

Accidents, Traffic↗

Development of immunoglobulin G and immunoglobulin E antibodies to cow's milk proteins and ovalbumin after a temporary neonatal exposure to hydrolyzed and whole cow's milk proteins.

The ingestion of food antigens usually results in the induction of oral tolerance, but the clinical and immunologic consequences of brief exposure to cow's milk proteins during the neonatal period are not well-documented. The aim of this work was to study immunoglobulin (Ig)E and IgG responses to cow's milk proteins and ovalbumin after exposure during the first three days of life in infants who were otherwise exclusively breast-fed. A group of 129 infants was randomly assigned at birth to one of three feeding regimens: human milk (HM), cow's milk formula (CMF), or a casein hydrolysate formula (CHF), during the first three days of life. They were then all exclusively breast-fed for a varying period of time and followed for two years. Serum IgG and IgE antibodies to cow's milk proteins and ovalbumin (OVA) were analyzed in blood samples obtained at birth, at 4 days and at 2, 4, 8, 12 and 24 months of age. The levels of IgG antibodies to beta-lactoglobulin (IgG-BLG) and bovine serum albumin (IgG-BSA) were higher in the CMF and the HM groups than in the CHF group for up to two years. This was particularly obvious for IgG-BLG in infants who started weaning before two months. The levels of IgG antibodies to casein (IgG-CAS) were higher in the CMF group, as compared with the CHF group at 8 and 12 months. The levels of IgG antibodies to OVA were similar in all three feeding groups. The levels of IgE antibodies to CAS or OVA were similar in the three feeding groups. Exposure to cow's milk during the first three days of life stimulated IgG antibody production to cow's milk proteins and this was still obvious at 2 years of age, while feeding with a casein hydrolysate during the first three days of life was associated with low levels of IgG antibodies to cow's milk proteins.

Animals↗

Allergy development and macromolecular absorption in infants with different feeding regimens during the first three days of life. A three-year prospective follow-up.

A group of 129 infants were randomly assigned at birth to one of three feeding regimens: human milk (HM), cow's milk formula (CMF) or a casein hydrolysate formula (CHF) during the first 3 days of life. Blood samples were taken on at 4 days and at 2, 4, 8, 12 and 24 months of age. Macromolecular absorption was analysed by measuring the serum concentration of human alpha-lactalbumin (S-alpha-LA) with a competitive radioimmunoassay (RIA). Total serum IgE was measured by RIA. A family history of allergy correlated to the proportion of infants with allergic symptoms both at 24 and 36 months of age (p = 0.03 and p = 0.04 respectively). In none of the three groups did correlation exist between the duration of breastfeeding and serum alpha-LA, serum IgE, family history of allergy, frequency of allergic symptoms and proportion of infants with infections.

Animals↗

Does early diet have an effect on subsequent macromolecular absorption and serum IgE?

A group of 130 healthy term infants were randomly assigned at birth to one of three feeding regimens for the first 3 days of life: human milk (HM), cow-milk formula (CMF), or a casein hydrolysate formula (CHF). The formula-fed infants received no human milk during the study days. After day 3, all infants were exclusively breast-fed. Blood samples were taken at 4 days and at 2 and 4 months of age during outpatient visits. Macromolecular absorption was analyzed 60 min after a feed of human milk by measuring the serum alpha-lactalbumin (S-alpha LA) concentrations by a competitive radioimmunoassay. Total serum IgE (S-IgE) was assayed by radioimmunoassay. The median S-IgE value was significantly lower at 2 months of age in the CHF group than in the HM group. The values remained significantly lower, even at 4 months of age, in the CHF group than in either the HM or the CMF group. The median S-alpha LA concentration at 2 months of age was significantly higher in the CHF group than in either the HM group or the CMF group. No significant differences could be found between the CMF and HM groups at any time. One infant in the HM group and one infant in the CMF group developed infantile colic. Two infants in the CHF group developed symptoms of cow-milk allergy. All other infants were healthy at 4 months of age.

Animals↗

Severity of alcohol dependence; rating by patient records.

A method to assess the severity of alcohol dependence by rating patient records was developed using the items of the 'alcohol abuse' subscale of the Swedish version of the Alcohol Use Inventory (AVI). The records of 37 alcoholics were rated and the scores were compared with the patients' self-report scores of the AVI and clinical assessments based on the structured clinical interview for DSM-III-R (SCID). The inter-rater reliability was rs = 0.88. The correlations between the record ratings and the alcoholics' self-ratings were rs = 0.77 for both raters and 0.55-0.57 between the record ratings and the total SCID-scores. The correlations between the self-ratings and SCID-scores were rs = 0.90. It is suggested that this method may facilitate record-based follow-up studies of alcoholics.

Adult↗

Macromolecular absorption in small-for-gestational-age infants.

Using human alpha-lactalbumin as a marker protein, macromolecular absorption was studied in 40 preterm infants, appropriate for gestational age (AGA), in 12 AGA term infants and in 18 preterm infants, small for gestational age (SGA). The absorption of alpha-lactalbumin was measured as concentration in serum after a human milk feed and expressed as micrograms alpha-lactalbumin/l serum/l human milk/kg body weight on day 7, 14, 21 and 42 after delivery. The serum concentration of alpha-lactalbumin was correlated negatively with maturity and postnatal age. In the SGA infants, the concentration of alpha-lactalbumin was significantly higher than in the AGA infants of similar gestational age. The data show that intrauterine growth retardation causes a delayed postnatal decrease in macromolecular absorption. This may indicate delayed intestinal maturation.

Birth Weight↗

Immunoreactive anionic trypsin and anionic elastase in human milk.

Immunoreactive anionic trypsin and anionic elastase have been demonstrated in human milk, by immunodiffusion and immunoelectrophoresis. Cationic trypsin and cationic elastase could not be detected by these methods. The anionic trypsin is probably present in complex with IgA. No benzoyl-DL-arginine-p-nitroanilide (BAPNA) splitting activity was found in human skim milk. Anionic trypsin was isolated by immunoadsorption chromatography. The purified enzyme had a BAPNA-splitting activity.

Anions↗

Immunichemical determination of cathodal elastase in human duodenal juice.

In human duodenal juice enzymes hydrolysing the elastase substrate succinyl-trialanine-p-nitroanilide have both an anodal and cathodal mobility in agarose gel electrophoresis. The cathodal enzyme, also having an elastinolytic activity, was purified. An application of electroimmunoassay for separate determination of this cathodal elastase is presented. Parallel estimations of esterolytic, elastinolytic and immunochemical activities in duodenal juice from a group of children revealed discrepancies suggesting both variations in the distribution of the two forms of "elastases", and presence of inactive forms.

Adult↗

Immunochemical determination of two trypsins in human duodenal juice.

An application of electroimmunoassay to the separate determination of anionic and cationic trypsin in human duodenal juice is presented. The proportions of anionic to cationic immunoactive trypsin in duodenal juice from a group of children averaged 20 : 80. The ratio of immunoactive to esterolytically (BAPNA) active trypsin averaged 1.6 : 1, indicating the presence of inactive forms of trypsin in duodenal juice.

Child↗

Effects of pure-tone sound, impulse noise, and vibration on visual orientation.

Eye movements and the electroencephalogram (EEG) were recorded in intact rabbits during an optokinetic test when the animals were exposed to pure-tone sound (85 dB at 4,000 Hz), impulse noise (159 dB), and vibration directed to the abdomen (at an amplitude of 0.9 mm at frequencies of 40 to 140 Hz). The frequency and velocity of optokinetic nystagmus significantly increased in response to these stimuli. The increase seen with vibration was greater than that resulting from sound, and the response was strongest when sound and vibration were combined. The increase of optokinetic nystagmus seen with induced vibration was progressive and dependent on the frequency. The increase was weakest during vibration at 40 Hz and strongest during vibration at 140 Hz. Electroencephalograms (EEGs) of the amygdaloid complex, dorsal hippocampus, midbrain reticular formation, and frontal motor cortex all were activated during exposure to sound and vibration, but activation of the hippocampal EEG was most closely related to the increase of optokinetic nystagmus. During optokinetic tests, impulse noise regularly triggered nystagmic beats. When the rabbits were not in the test apparatus, nystagmus was produced in response to about 18 per cent of the presentations of impulse noise, while activation of the EEG was constant. Thus, vibration and noise, when excessive, may interfere with visual orientation and hence disturb equilibrium. These findings can be related to the nonspecific dizziness that occurs in aerospace or industrial workers exposed to excessive noise and vibration.

Acoustic Stimulation↗