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Biomedical subjects

B Andersson

Publications and source records attributed to B Andersson.

At least 343 records · Page 19Linked to original sources
PubMed1990

Photosystem II characteristics of a constructed Synechocystis 6803 mutant lacking synthesis of the D1 polypeptide.

Photosystem II (PSII) composition was studied in a mutant of the cyanobacterium Synechosystis 6803 in which synthesis of the reaction center polypeptide D1 has been inactivated. The mutant thylakoids had lost also the other reaction center polypeptide D2 and the chlorophyll alpha-binding protein CP47. Cytochrome b559 and the chlorophyll alpha-binding protein CP43 accumulated to almost wild-type amounts in mutant thylakoids. Also the 33 kDa polypeptide involved in water oxidation was present and membrane-bound in mutant thylakoids. The intrinsic 22 kDa polypeptide, so far known only from plants, was detected both in wild-type and mutant thylakoids.

Cyanobacteria↗
PubMed1990

Two mutations within the coding sequence of the phenylalanine hydroxylase gene.

Two previously unidentified mutations at the phenylalanine hydroxylase locus were found during a study of the relationship between genotype and phenotype in phenylketonuria and hyperphenylalaninemia. One mutation eliminates the BamHI site in exon 7 and the other eliminates the HindIII site in exon 11 of the phenylalanine hydroxylase gene. They were suspected because of deviating restriction fragment patterns and confirmed by amplification, via the polymerase chain reaction, of exon 7 and exon 11, respectively, followed by digestion with the appropriate restriction enzyme. Direct sequencing of amplified mutant exon 7 revealed a G/C to T/A transversion at the first base of codon 272, substituting a GGA glycine codon for a UGA stop codon. Direct sequencing of amplified mutant exon 11 revealed a deletion of codon 364, a CTT leucine codon. The exon 7 mutation can be expected to result in a truncated protein and the exon 11 mutation in the elimination of an amino acid in the catalytic region of the enzyme. A patient who is a compound heterozygote for these two mutations has classical phenylketonuria. It is concluded that each of the two mutations leads to a profound loss of enzymatic activity. The segregation of these mutations with disease alleles in 4 and 2 families, respectively, supports the hypothesis that multiple mutations at the phenylalanine hydroxylase locus explain the variable phenylalanine tolerance in patients with phenylalanine hydroxylase deficiency.

Alleles↗
PubMed1990

Mutations induced by benzo[a]pyrene diolepoxide at the hprt locus in human T-lymphocytes in vitro.

Human T-lymphocytes have been treated with benzo[a]pyrene diolepoxide (BPDE) in vitro and T-cell clones mutated in the hprt gene have been isolated. The mutant frequencies in BPDE-treated T-cell cultures were on average 24-fold higher than those of untreated cultures. Thus, BPDE is a potent inducer of gene mutation in this system. In order to examine which types of mutations are induced by BPDE in human cells, 41 spontaneous and 44 BPDE-induced mutant clones have been characterized using the Southern blot technique. In addition, rearrangements of the T-cell-receptor beta and gamma loci have been used to determine the proportion of isolated clones that are unique, and thus likely to represent independent mutational events. Out of 23 independent spontaneous mutants 4 had large hprt alterations that could be detected on Southern blots. Two of these alterations, deletions of exons 2-6, have been confirmed using PCR of hprt cDNA and direct sequencing of the PCR product. All 33 independent BPDE-induced mutants had normal hprt restriction patterns which indicates that BPDE is mainly a point mutagen in this system.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1990

Immunofluorescence demonstration of digoxin in human myocardial tissue and isolated rat cardiac myocytes with monoclonal antibodies.

The aim of the present investigation was to identify the morphological correlates of digoxin binding sites in human heart muscle tissue and isolated viable rat heart myocytes. Cardiac glycoside linked to myocardial cells was demonstrated by monoclonal digoxin specific antibody and by FITC-conjugated anti-mouse immunoglobin serum. This versatile immunofluorescence method can be used in diagnostic and experimental studies of cardiac glycoside binding.

Animals↗
PubMed1990

Anti-adhesive activity of human casein against Streptococcus pneumoniae and Haemophilus influenzae.

The casein fraction of human milk was found to inhibit the attachment of Streptococcus pneumoniae and Haemophilus influenzae human respiratory tract epithelial cells. The inhibitory activity for S. pneumoniae remained after heat and trypsin treatment of the casein and was found in oligosaccharides released from casein. kappa-Casein, which is the most highly glycosylated casein component, inhibited pneumococcal attachment at concentrations similar to the whole casein fraction. The results are consistent with the known recognition of GlcNAc beta 1-3Gal by S. pneumoniae, since human milk and bovine colostrum, which contain GlcNAc, inhibited attachment, but mature bovine milk lacking GlcNAc did not. The effect on H. influenzae was similar to that on S. pneumoniae in that the attachment was inhibited by human casein and bovine colostrum, but not by either mature bovine milk or by the bovine casein fraction. The kappa-casein component of human milk was a less efficient inhibitor of H. influenzae attachment than the whole casein fraction and the free oligosaccharides were inactive. This anti-microbial effect of human casein represents a new mechanism for the protection by breast-milk against respiratory tract infection.

Animals↗
PubMed1990

A double-blind comparison of intranasal budesonide with placebo for nasal polyposis.

Intranasal budesonide, 400 micrograms two times a day, was evaluated in 36 patients referred for treatment of nasal polyposis. The age range was 20 to 68 years. Polypectomy was done 5.6 (mean) times previously. After a 5-week, treatment-free, baseline period, patients were treated in a double-blind fashion with either budesonide or placebo during 4 weeks. After this treatment period, placebo-treated patients started receiving budesonide in an open trial for an additional 4 weeks. The patients rated their nasal symptoms daily. Nasal examinations and nasal inspiratory flow rate (IFR) measurements were done at clinic visits. After 3 and 4 weeks of treatment, the response to budesonide was significantly greater than response to placebo. The greater reduction in nasal blockage caused by polyps, observed on physical examination, p = 0.005, was mirrored by an increase in nasal IFR (p = 0.0001). Patient rating of the severity and frequency of nasal blockage were reduced more by budesonide than by placebo (p less than or equal to 0.0005). Switching placebo-treated patients to budesonide treatment resulted in a reduction of nasal blockage (p less than 0.001) and an increase in nasal IFR (p less than 0.001). The results demonstrate that topical nasal budesonide, 400 micrograms two times a day, is an effective treatment of nasal polyps.

Administration, Intranasal↗
PubMed1990

Gamma-globulin treatment of recurrent acute otitis media in children.

This study examined the hypothesis that children prone to acute otitis media have a reduced concentration of circulating antibodies of the IgG2 subclass and that this defect can be compensated for by gamma-globulin treatment. Infants and children below 18 months of age with at least three episodes of acute otitis media were randomized to intramuscular gamma-globulin or no treatment and were followed for 6 months. We could demonstrate neither reduced IgG2 nor specific anti-polysaccharide antibody activity in the otitis-prone children. In contrast they had higher concentrations of IgG2 and antibodies to phosphorylcholine than did age-matched controls. There was neither a relationship between the IgG2 concentration and the number of otitis episodes prior to enrollment nor a reduction in otitis frequency in the gamma-globulin-treated group.

Acute Disease↗
PubMed1990

Influence of menopause on dietary treatment of obesity.

Obese women (n = 104) were treated with an energy reduced diet (1100 kcal d-1) in a strictly standardized outpatient regime. Body composition, regional adipose tissue distribution, regional fat cell sizes and metabolic variables were followed before treatment, after 5% weight loss and at the stage when there was no further weight loss. Premenopausal women lost less body fat and relapsed earlier after treatment, compared with menopausal women. Fat loss appeared to be more uniform, and included several adipose tissue regions in postmenopausal women, while younger women seemed to lose fat mainly from the epigastrial fat cells. Higher baseline levels of thyroid hormones were associated with increased fat loss and a tendency to lose less lean body mass. Waist/hip and waist/thigh ratios did not change in response to weight loss. The addition of fibre to the diet did not affect the rate of relapse. These results suggest that obesity treatment by implementation of a negative calorie balance might be more successful in postmenopausal than in younger women, perhaps due to the more uniform availability of body fat in the former.

Body Mass Index↗
PubMed1990

The increased number of epithelial mast cells in nasal polyps and adjacent turbinates is not allergy-dependent.

Respiratory epithelial mast cells are an expression of airway inflammatory processes. Nasal epithelial mast cells are known to be increased in allergic rhinitis and have now been examined in patients with nasal polyps. Metachromatic cell counts (mean +/- standard error) expressed as the sum of large mast cells, atypical mast cells and basophils in epithelial scrapings of the inferior turbinates, assessed after Carnoy's fixation and toluidine blue staining (pH 0.5), were 37.5 +/- 29 in non-allergic normal control subjects (n = 11), 435 +/- 130 in polyp patients who were allergic (n = 18), and 699 +/- 267 in polyp patients who were not allergic (n = 8). Metachromatic cell counts in epithelial scrapings obtained in vivo from nasal polyps of allergic patients (n = 8) were 1769 +/- 962, and 2308 +/- 1544 from polyps of non-allergic patients (n = 5); metachromatic counts were 2089 +/- 633 in epithelial scrapings from excised polyps of allergic patients (n = 14) and 2214 +/- 640 from polyps of non-allergic patients (n = 13). It is concluded that the number of metachromatic cells in the epithelium of nasal polyps and the adjacent nasal mucosa is elevated compared with normal nasal epithelium and the increased number does not depend upon allergy.

Humans↗
PubMed1990

Inhibition of the cortisol response to systemic angiotensin II by forebrain lesions involving the anterior wall of the third ventricle.

The influence of bilaterally narrow, medial forebrain lesions on the increase in plasma cortisol concentration normally seen in response to intravenous angiotensin II was studied in five goats. For comparison, the pre- and post-lesion cortisol responses to intravenous endotoxin were also evaluated. The cortisol response to angiotensin was extinguished in two goats, whereas a slightly attenuated response to endotoxin was still obtained post-lesioning. In these animals the lesions embraced the subfornical organ (SFO), the organum vasculosum of the lamina terminals (OVLT) and the interjacent anterior wall of the third ventricle. In two other goats, in which the SFO was completely destroyed but the OVLT remained largely intact, the lesions caused about 50% reduction of the cortisol response to angiotensin without any concomitant reduction of the response to endotoxin. It is concluded that ACTH-cortisol release in response to systemic angiotensin II is not mediated exclusively by receptors for the octapeptide confined to the SFO. Angiotensin receptors in the OVLT seem to be equally important in this respect.

Adrenocorticotropic Hormone↗
PubMed1990

Influence of blood group type on prognosis of transitional cell carcinoma of the urinary bladder.

The correlation of blood group to grade, stage and tumor markers at diagnosis and to the subsequent clinical course was investigated in a consecutive retrospective series of 230 patients with primary transitional cell carcinoma of the urinary bladder. The follow-up period was 5-9 years. There were no significant differences in grade, stage or DNA ploidy between patients of blood groups A and O. However, the deletion of ABH blood group isoantigen was found more frequently in tumors from patients of blood group O. Concerning progression of superficial bladder tumors, this was found earlier among patients of blood group O, and in a multivariate analysis this emerged as an independent prognostic factor. The crude and corrected mortality was not significantly higher among patients of group O than among those of other blood groups.

Adult↗
PubMed1990

Mapping of a functional autoimmune epitope on the beta 1-adrenergic receptor in patients with idiopathic dilated cardiomyopathy.

The presence and properties of serum autoantibodies against beta-adrenergic receptors in patients with idiopathic dilated cardiomyopathy were studied using synthetic peptides derived from the predicted sequences of the human beta-adrenergic receptors. Peptides corresponding to the sequences of the second extracellular loop of the human beta 1- and beta 2-adrenergic receptors were used as antigens in an enzyme immunoassay to screen sera from patients with dilated cardiomyopathy (n = 42), ischemic heart disease (n = 17), or healthy blood donors (n = 34). The sera of thirteen dilated cardiomyopathy patients, none of the ischemic heart disease patients, and four of the healthy controls monospecifically recognized the beta 1-peptide. Only affinity-purified antibodies of these patients had a inhibitory effect on radioligand binding to the beta 1 receptor of C6 rat glioma cells. They recognized the receptor protein by immunoblot and bound in situ to human myocardial tissue. We conclude that a subgroup of patients with idiopathic dilated cardiomyopathy have in their sera autoantibodies specifically directed against the second extracellular loop of the beta 1-adrenergic receptor. These antibodies could serve as a marker of an autoimmune response with physiological and/or pathological implications.

Adult↗
PubMed1990

High anti-phosphorylcholine antibody levels and mortality associated with pneumonia.

Phosphorylcholine is an immunodominant determinant of pneumococcal teichoic acids. Antibodies to phosphorylcholine are naturally occurring in man and decline in amount with age. Since antibodies to phosphorylcholine are markers of the immune responsiveness to polysaccharides and since anti-polysaccharide antibodies are highly protective against most bacterial pneumonia we expected a higher rate of pneumonia in elderly individuals with low levels of antibodies to phosphorylcholine. The relationship between the levels of antibodies to phosphorylcholine and mortality was analyzed prospectively in a representative sample of elderly individuals. A significant anti-phosphorylcholine antibody response occurred in a subgroup of the probands. There was a strong association (p less than 0.0001) between high levels of antibodies to phosphorylcholine in the serum at 70 years of age and pneumonia related death up to 14 years later. A similarly strong association was not observed between mortality and the antibody titer to another naturally occurring polysaccharide antigen: the blood group B antigen. Furthermore, there was no association between mortality due to diseases other than pneumonia and the levels of antibodies to phosphorylcholine. The association between antibody levels and subsequent fatal pneumonia provides a means of detecting individuals at risk for pneumonia-related death.

Age Factors↗
PubMed1990

Synthesis of 3-dialkylaminochromans via thallium(III)-induced cyclization of allyl aryl ethers.

The sulfur-containing 3-alkylaminochromans, 5-methoxy-3-[N-(2- methylthioethyl)-propylamino]chroman (15), 5-hydroxy-3-[N-(2-methylthioethyl)propylamino]chroman (5) and 5-methoxy-8-methylthio-3-(dipropylamino)chroman (6), have been prepared from 8-bromo-5-methoxy-3-chromanol (11). This precursor was synthesized from 3-allyloxy-4-bromoanisole (8), by a thallium(III)-mediated ring-closure reaction. Compound 11 also served as starting material for the synthesis of 8-bromo-3-(dipropylamino)-5-methoxychroman (7).

Chromans↗
PubMed1990

Class II composite resin restorations: a three-year clinical study of six different posterior composites.

Class II restorations of five light-cured posterior composite materials (Occlusion, P 30, Fulfil, Profile and Heliomolar) were followed for three years, and restorations of another material (Distalite) were followed for two years. Twenty-four dentists from The Public Dental Health Service in the county of Bohuslän placed 242 Class II restorations in 213 patients. The restorations were evaluated after three years using the USPHS criteria. Stone casts were used to categorize quantitatively the amount of occlusal wear according to the Leinfelder method. No differences could be found between the different materials regarding clinical properties. The failure rate (USPHS ratings Charlie) was low, 6.5 per cent. The average occlusal wear after three years for most of the materials was about 100 micrometers. Heliomolar showed a better resistance to wear compared with the other materials.

Acid Etching, Dental↗
PubMed1989

Metabolism of adipose tissue in intraabdominal depots of nonobese men and women.

Adipocyte size, lipoprotein lipase (LPL) activity, and the lipolytic response to noradrenaline and isoproterenol were studied in three intraabdominal depots (mesenteric, omental, retroperitoneal), as well as in subcutaneous abdominal adipose tissue, in nonobese groups of middle-aged men and in premenopausal and postmenopausal women. Subcutaneous adipocytes were larger than intraabdominal adipocytes in all groups. The men had large adipocytes in all intraabdominal depots as compared with the women. The premenopausal women seemed to have low LPL activity in intraabdominal depots. Two types of responses to catecholamine-stimulated lipolysis were observed: a similar response from mesenteric and omental (portal) fat depots and from retroperitoneal and subcutaneous abdominal (nonportal) fat depots. Young women had higher lipolysis in nonportal than in portal adipose tissues. In the men the reverse characteristics were found. These dissimilarities seem to be based on differences in beta-adrenergic responsiveness. Postmenopausal women showed no differences between depots. The differences in lipolytic responsiveness between these groups might be caused by sex steroid hormones.

Abdomen↗