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Biomedical subjects

B Andersson

Publications and source records attributed to B Andersson.

At least 361 records · Page 20Linked to original sources
PubMed1989

Dichotic listening in 126 left-handed children: ear advantages, familial sinistrality and sex differences.

In the present study we report data on dichotic listening (DL) performance in 126 left-handed children. Four specific questions were addressed: (1) What is the percentage of left-handers in a large sample of children in Sweden? (2) What is the distribution of children showing a right ear (REA), left ear (LEA), and no ear (NEA) advantage in DL? (3) What is the relationship between ear advantage and familial sinistrality in children? (4) Are there sex differences among left-handed children, and if so, are these differences also reflected in DL performance? The results showed that the left-handers constituted 8.1% of the total sample of the screened subjects. The DL results showed 65.0% REA, 25.4% LEA, and 9.6% NEA. Of the subjects, 45.2% had left-handed relatives. Overall, there were more boys than girls in the sample (65.1% vs 34.9%). It is concluded that the present data match the sodium-Amytal data on left-handed adults with about 2/3 of a left-handed population with left hemisphere language dominance.

Child↗
PubMed1989

Arterial embolism and atrial arrhythmias.

In a retrospective study, the frequency of atrial arrhythmias of types known to cause systemic embolisation and the effect of anticoagulant treatment were studied in 106 patients with arterial embolism. Such embolising arrhythimas were found in 84 patients (79%). Permanent atrial fibrillation was documented in 53 patients (50%) and episodic atrial arrhythmia was encountered in 28 patients (26%). In 21 of 28 patients with sinus rhythm on admission, an embolising arrhythmia could be identified in previous ECG recordings. Patients with atrial arrhythmias had a significantly higher rate of prior embolic episodes and embolic events during follow-up (53 events in 84 patients) compared to the patients without arrhythmia (6 events in 22 patients) (P less than 0.05). In patients with atrial arrhythmias postoperative treatment with peroral anticoagulation was associated with a lower mortality (P less than 0.003) and a lower rate of reembolisation and stroke (P less than 0.0005). It is concluded that every fourth patient presenting with arterial embolism had an atrial arrhythmia of episodic nature. Most of these patients had normal sinus rhythm on admission but could be identified in previous ECG recordings. This study suggests that patients with arterial embolism and atrial arrhythmia have a higher risk of further embolisation with an ensuing risk of morbidity and death, compared to patients without arrhythmia. A positive effect of anticoagulation seemed to be present in patients with atrial arrhythmia whereas such a positive effect could not be identified in patients without arrhythmia.

Anticoagulants↗
PubMed1989

Resolved 6,7,8,9-tetrahydro-N,N-dimethyl-3H-benz[e]indol-8-amine: central dopamine and serotonin receptor stimulating properties.

The enantiomers of 6,7,8,9-tetrahydro-N,N-dimethyl-3H-benz[e]indol-8- amine (1a) were prepared and tested for their actions on central dopamine and serotonin (5-HT) receptors. The dopaminergic effects were shown to reside in the (1)-R enantiomer. It was shown that compound 1a and its (+)-R enantiomer possess potent central 5-HT1A receptor stimulating properties.

Animals↗
PubMed1989

Age-related change in anti-carbohydrate antibody levels.

It has been proposed that immunity declines with age. Most evidence for this hypothesis has been obtained from cross-sectional samples of unrelated populations that differ in age, antigen exposure, and morbidity. In the present study, the authors used serum samples collected repeatedly from the same persons in longitudinal studies. Two representative samples of the population in Göteborg, Sweden were obtained; the first was studied at ages 38, 50, and 62 years, and the second at ages 70, 75, 79, and 81 years, respectively. The phosphorylcholine determinant of pneumococcal teichoic acid and the B blood group determinant were selected as model polysaccharide antigens. The results demonstrate a consistent decline in individual antibody levels in the decades before age 70 years but not later. Antibodies to phosphorylcholine and blood group B were highly parallel, suggesting that the decline was a general phenomenon for antibodies to polysaccharide antigens.

ABO Blood-Group System↗
PubMed1989

Combination of blood group ABH antigen status and DNA ploidy as independent prognostic factor in transitional cell carcinoma of the urinary bladder.

The prognostic value of DNA ploidy and blood group (ABH) antigen reactivity was studied in a consecutive retrospective study of 230 patients with primary transitional cell carcinoma of the urinary bladder. In 195 cases the DNA ploidy and ABH reactivity could be assessed in paraffin-embedded tissue. Early progression (in the first 3 years) occurred in 2% of the patients with diploid ABH positive tumours and in 31% of those with aneuploid ABH negative tumours. The 5-year survival rates corrected for intercurrent mortality were 95 and 56% respectively. In a Cox multivariate analysis, T category, age at diagnosis and histological grade emerged as significant independent prognostic indicators of bladder cancer death, whereas ABH reactivity and DNA ploidy had no significant independent value. However, if the combination of ABH reactivity and DNA ploidy was included in the Cox model, this and T category were independent predictors. When this Cox model was applied to assess the risk of progression, the only independent prognostic factor was the combination of ABH reactivity and DNA ploidy.

ABO Blood-Group System↗
PubMed1989

Attachment of Streptococcus pneumoniae to human pharyngeal epithelial cells.

Streptococcus pneumoniae and Haemophilus influenzae are major respiratory pathogens. They attach to the mucosal surfaces of the respiratory tract. This attachment is the first contact with the host tissues and may determine whether the bacteria will colonize the mucosa and cause infection. Conversely, if attachment is inhibited, the infection may be prevented. Our studies have defined the mechanisms of pneumococcal attachment as a specific interaction between bacterial proteins and epithelial cell glycoconjugates. The free oligosaccharide blocks adhesion. So does human milk, which contains the receptor oligosaccharides. The accessibility of receptors is likely to be influenced by secreted substances like mucins, surfactant, etc. The effect of such components has not been evaluated. Ambroxol, bromhexin, as well as secretions from individuals treated with the substances may have such activity.

Ambroxol↗
PubMed1989

Response to salvage therapy and survival after relapse in acute myelogenous leukemia.

The response to and survival following first salvage therapy regimens for 243 patients with acute myelogenous leukemia (AML) treated between 1974 and 1985 were evaluated. Eighty (33%) patients obtained a complete remission (CR), 24% died prior to achieving a response, and 43% were resistant on their first salvage regimen. The median survival was 18 weeks. Five percent overall and 16% of the CR patients are predicted to survive for more than 5 years. The factor most strongly associated with response and survival was the duration of the initial remission with 49 of 82 (60%) patients whose initial CR duration was at least 1 year in duration obtaining a second CR v 31 of 161 (19%) for patients with a shorter remission (P less than .01). Age, liver function, serum lactic dehydrogenase (LDH), karyotype, and the proportion of blasts plus promyelocytes present at the time of starting salvage therapy were strongly associated with probability of response and survival. Multivariate analysis was used to develop logistic regression and proportional hazard models to predict probability of response and survival, respectively. The major regimens used were conventional-dose cytarabine (ara-C) (combined with anthracyclines or amsacrine), high-dose ara-C, rubidazone, amsacrine (AMSA), other anthracyclines, and autologous or allogeneic transplant programs. After allowing for the prognostic factors in the models, specific treatment regimens were not strongly associated with prognosis.

Adult↗
PubMed1989

Visual half-field tests of lateralized letter presentations: differences between preliterate and literate children.

In the present study, hemispheric differences in global and analytic processing were investigated in preliterate and literate children, using the "dual-letter" matching task paradigm (Navon, 1977). The stimuli consisted of lateralized visual presentations of large uppercase letters made up of small uppercase letters. The task of the subject was to decide on each trial if the large or small letters were the same or not. Vocal reaction time (VRT) and error-frequency were used as dependent measures. In Experiment 1, 28 right-handed 8-years old children participated. The children were split into a preliterate and a literate group depending on teachers evaluations, and on scores on a reading test. The results showed longer VRTs for the preliterate children when the stimuli were initially presented to the right hemisphere and especially when the subjects were required to match the small letters. These results were followed up in Experiment 2, where the preliterate subjects were split into "fast" and "slow" readers. The results showed that the "slow" readers were more impaired in processing the letter stimuli when the stimuli were initially presented to the right hemisphere. It is concluded that hemispheric asymmetry for letter processing interacts with the development of normal reading ability in children.

Child↗
PubMed1989

Alternative 5' end of the bcr-abl transcript in chronic myelogenous leukemia.

Philadelphia chromosome positive acute lymphocytic leukemia and chronic myelogenous leukemia are strongly associated with two distinct forms of bcr-abl chimeric protein, known as P190 and P210, respectively. By studying cDNA clones obtained from the cell line KBM-5, we identified two new bcr-abl transcripts. These are formed by alternative splicing of at least two exons to the known bcr exon 2. One novel transcript can encode a protein kinase of approximately 190 kd, while the other can direct the synthesis of a larger protein whose amino terminus remains to be defined. The alternative exons can be spliced also to the two normal bcr transcripts, reflecting the activation of a cryptic promoter. These messages were present at low abundance in two cases of blastic crisis but were not detected in the chronic phase. It is conceivable that the proteins encoded by the new bcr-abl mRNAs are involved in the transformation to the acute phase in some cases of chronic myelogenous leukemia.

Amino Acid Sequence↗
PubMed1988

Effect of differentiation-inducing agents on oncogene expression in a chronic myelogenous leukemia cell line.

K562 is a Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) blast crisis cell line representing a pluripotent precursor cell. At the molecular level, K562 cells express high levels of the aberrant bcr-abl product, p210bcr-abl, believed to be critical to the pathogenesis of CML. The authors demonstrate that exposure of K562 cells to hemin causes a state of partial, reversible erythroid maturation, accompanied by a marked decrease in p210bcr-abl. The change in bcr-abl expression may be mediated at the translational level since steady state amounts and enzymatic activity of the bcr-abl protein are reduced whereas bcr-abl mRNA levels are unaltered. The decrease in p210bcr-abl phosphokinase enzymatic activity can be detected within 2 hours after addition of hemin to the culture media, indicating that changes in expression of this oncogene probably occur before or concurrent with differentiation. No change in bcr-abl protein occurred in a CML cell line (KBM-5) which did not undergo differentiation after exposure to hemin, consistent with a direct relationship between altered p210bcr-abl expression and hemin-induced erythroid differentiation. Importantly, the marked diminution in bcr-abl protein was not associated with a disruption in K562 growth rates, indicating that the proliferative capacity of these cells may be independent of the bcr-abl product. In contrast to hemin, cytosine arabinoside (Ara-C) caused terminal erythroid differentiation of K562 cells, characterized by irreversible hemoglobin accumulation and cytostasis; and no change in bcr-abl protein expression was observed. The distinct effects of Ara-C and hemin could reflect the existence of pleiotropic differentiation pathways. Both Ara-C and hemin-exposed cells showed a decrease in c-myc and c-myb transcripts, suggesting that altered levels of these proto-oncogenes may be associated with erythroid maturation, regardless of the rate of cell division. K562 cells provide a useful model for analyzing the interaction between oncogene expression and CML cell growth and differentiation.

Cell Differentiation↗
PubMed1988

Treatment of the blastic phase of chronic myelogenous leukemia with mitoxantrone and high-dose cytosine arabinoside.

Twenty-seven patients in the blastic phase of chronic myelogenous leukemia received combination chemotherapy with mitoxantrone 5 mg/m2 intravenously daily for 5 days, and cytosine arabinoside 3 g/m2 intravenously over 2 hours every 12 hours for six doses. The patients' median age was 42 years (range, 19-61 years), and 26 of them had Philadelphia chromosome-positive disease. Overall, seven patients (26%) achieved complete remission, and one (4%) had a partial remission for an overall response rate of 30%. Eight patients died during remission induction, and 11 had resistant disease. The median survival was 14 weeks for the total population, and 24 weeks for patients achieving a complete remission. The nonmyelosuppressive toxicity of the combination was acceptable; serious neurologic and pulmonary toxicities were uncommon. Significant marrow hypoplasia was observed resulting in a high incidence of febrile episodes (85% of patients). The combination of mitoxantrone and high-dose cytosine arabinoside did not significantly improve overall prognosis. Since chemotherapy continues to produce disappointing results, other innovative approaches need to be explored.

Adult↗
PubMed1988

Mitoxantrone and high-dose cytosine arabinoside in refractory acute myelogenous leukemia.

Forty-four patients with a diagnosis of refractory or relapsed acute myelogenous leukemia received salvage chemotherapy with high-dose cytosine arabinosine 3 g/m2 intravenously over 2 hours every 12 hours for six doses and mitoxantrone 5 mg/m2 intravenously daily for 5 days. Overall 16 patients (36%) had a complete remission; 16 patients (36%) had resistant disease; and 12 (27%) died during induction therapy. The most significant predictive factor for remission was the duration of first remission: the response rate was 17% for patients whose first remission duration was shorter than 12 months (including those who did not achieve a first remission), 45% for those with a first remission lasting between 12 to 18 months, and 69% for those with longer remission durations (P = 0.008). Other predictive factors for higher response rates were a younger age group, a good performance status, and a favorable or diploid karyotype. The median survival from start of therapy was 4 months for the total population and 10 months for patients with remission. Serious side effects including pulmonary toxicity and neurotoxicity occurred in less than 10% of patients. This incidence was significantly lower than previous high-dose cytosine arabinoside schedules of 3 g/m2 for nine to 12 doses (total dose, 27 to 36 g per course). Significant granulocytopenia and thrombocytopenia were universal resulting in fever or documented infections in 98% of patients. We conclude that the combination of high-dose cytosine arabinoside and mitoxantrone is an effective antileukemic regimen with acceptable toxicity. Future studies should incorporate it as part of the frontline induction or maintenance strategies in newly diagnosed patients with acute myelogenous leukemia.

Adolescent↗
PubMed1988

Nucleotide sequence of cDNA clones encoding the complete precursor for the "10-kDa" polypeptide of photosystem II from spinach.

By screening lambda gt11 cDNA expression libraries prepared from poly(A+) RNA of illuminated (4 and 16 h) spinach seedlings (Spinacia oleracea var. Monatol), we have recovered phage containing inserts corresponding to the complete "10-kDa" precursor polypeptide associated with the water oxidizing photosystem II. The amino acid sequence deduced from the nucleotide sequence indicates a polypeptide of 140 amino acid residues (15.0 kDa). The mature protein is predicted to consist of 99 amino acid residues (10.8 kDa). The identity of the recombinant DNAs was established serologically and by determining an N-terminal sequence of 25 amino acid residues from the purified authentic protein. This sequence was found in the cDNA-derived amino acid sequence. In addition, a monospecific antiserum detected the appropriate polypeptides when copy-RNA was translated into protein which was imported into isolated unbroken chloroplasts. The transit sequence (41 amino acid residues; 4.2 kDa) is markedly dissimilar to those of the three extrinsic, luminal photosystem II proteins. Secondary structure prediction suggests a transmembrane arrangement of the 10-kDa polypeptide in the thylakoid membrane, with the N terminus in the thylakoid lumen and a 17-amino acid C-terminal sequence at the outside partitions. This is consistent with biochemical and functional data for the protein. A major transcript of 1.0 kilobases has been observed in polyadenylated RNA.

Amino Acid Sequence↗
PubMed1988

Thermal degradation of weldable poly(vinyl chloride) samples at low temperatures.

A study was performed to determine possible emission products during plastic welding that may be responsible for health problems. Thermal degradation of poly(vinyl chloride) samples was carried out at 170 degrees C in a thermal desorption gas chromatography (GC) injector and in a modified impinger in a GC oven, in combination with various analytical techniques, thermogravimetric analysis, capillary GC, GC-mass spectrometry, high-performance liquid chromatography and isotachophoresis. Some of the degradation products found are known to be eye irritants.

Adsorption↗
PubMed1988

Generation and isolation of cyanobacterial inside-out thylakoid vesicles.

A method has been designed to prepare inside-out thylakoid vesicles from a cyanobacterial species (Phormidium laminosum). Everted thylakoid vesicles could be generated by Yeda press treatment after induced membrane pairing. Membrane pairing was induced either by addition of high concentrations of Mg2+ ions or by lowering the pH of the fragmentation media. The inside-out vesicles were isolated by aqueous polymer two-phase partition. The membrane orientation was determined by proton translocation studies and freeze-fracture electron microscopy.

Cell Fractionation↗
PubMed1988

Protein serotyping of Streptococcus pneumoniae based on reactivity to six monoclonal antibodies.

Six monoclonal antibodies to proteins of Streptococcus pneumoniae were tested in a dot blot assay for reactivity with 499 clinical isolates of pneumococci. Forty-four percent of the isolates reacted with at least one of the antibodies. Nineteen patterns of reactivity were identified and each designated as a provisional protein serotype. Protein serotyping identified pneumococcal strains independently of their capsular type and made it possible to differentiate strains within most capsular types. A protein serotyping system provides a new dimension to the phenotypic identification of S. pneumoniae and may eventually provide a basis for assessing the population structure of these organisms.

Animals↗
PubMed1988

A sandwich adhesion on Streptococcus pneumoniae attaching to human oropharyngeal epithelial cells in vitro.

Streptococcus pneumoniae attach to human pharyngeal epithelial cells through the specific interaction of bacterial surface adhesins with glycoconjugate receptors. The present study defines the adhesin as a molecule bridging between an anchoring site in the bacterial cell wall and the epithelial cell receptor. The nature of the adhesin was defined in three ways: First, the attachment of whole bacteria was reduced by trypsin, periodate and heat. Second, heat treatment of whole bacteria was shown to release material, which was able to reconstitute the adherence. The heat extract bound to epithelial cells, as shown by fluorescence labelling, and agglutinated latex beads covalently coupled with receptor oligosaccharide. Active material could be extracted by heat from both high and low adhering strains, but could reconstitute only attaching strains. Third, the bacterial component binding the adhesin was localized to protoplasts and cell wall fractions obtained by mechanical or deoxycholate induced lysis of pneumococci. Isolated pneumococcal surface components, which did not inhibit attachment, included peptidoglycan, C polysaccharide, Forssmann antigen, capsular polysaccharide and a phenol extract produced in analogy to streptococcal lipoteichoic acid. The procedure used to extract the adhesin was previously used to prepare the competence factor. The competence deficient mutant RA7- attached poorly compared to the competent R6 parent. The possible relatedness of attachment to competence is discussed.

Adhesins, Bacterial↗