Biomedical subjects

B Andersson

Publications and source records attributed to B Andersson.

At least 235 records · Page 13Linked to original sources

PubMed1995

Influence of forebrain lesions and isoflurane anaesthesia, respectively, on responses to the intracarotid infusion of angiotensin II in sheep.

In conscious sheep, lesions involving the anterior wall of the third cerebral ventricle extinguished the dipsogenic and cortisol releasing effects of 10 min intracarotid (i.c.) infusions of angiotensin II (Ang II) (20 pmol kg-1 min-1). The sustained hypertension obtained in response to i.c. Ang II in the intact animal was not significantly changed by the forebrain lesions. Pronounced, but short-lasting tachycardia immediately developed in response to i.c. Ang II in control animals. After a 1 min return to initial values the heart rate (HR) rose to about 20 beats min-1 above pre-infusion level during the remaining infusion period. After a brief post-infusion fall, HR retook that level. It then gradually declined but did not return to initial level until about 25 min later. During isoflurane anaesthesia in the latter animals carotid blood pressure (cBP) was reduced by approximately 30% while the HR was more than doubled. The cBP rise in response to i.c. Ang II infusion was < 50% of that seen in awake animals and the pressure returned to initial level within approximately 5 min after the end of the infusion. The infusion did not influence the HR. This study provides support for the idea that blood borne Ang II, bound at cerebral sites posterior to the hypothalamic region, continues to have cardiovascular effects for approximately 20 min after the concentration in the blood has returned to pre-infusion level.

Anesthesia↗

PubMed1995

Identification of volatile metabolites from five fungal species cultivated on two media.

Five fungal species, Aspergillus versicolor, Penicillium commune, Cladosporium cladosporioides, Paecilomyces variotii, and Phialophora fastigiata, were cultivated on two media, malt extract agar and dichloran glycerol agar. Culture flasks provided with inlet and outlet tubes were used and purified, and humidified air was constantly led through the flasks. Air samples from the cultures were sorbed on Tenax GR and analyzed by thermal desorption-gas chromatography. The produced volatile metabolites were analyzed by mass spectrometry. Various hydrocarbons, alcohols, ketones, ethers, esters, sulfur-containing compounds, and terpenes were identified. The most commonly produced substances were 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methylfuran, and dimethyl disulfide. The production was highly dependent on both medium and species.

Journal Article↗

PubMed1995

Bronchial inflammation in chronic bronchitis assessed by measurement of cell products in bronchial lavage fluid.

BACKGROUND: Bronchial inflammation in chronic bronchitis has not been characterised as well as in asthma. The present study was undertaken to assess whether a characteristic pattern of bronchial inflammatory markers could be found in patients with chronic bronchitis. METHODS: Bronchoscopy with bronchial lavage was performed in 42 patients with chronic bronchitis and in 13 healthy controls. Twenty three of the patients had non-obstructive chronic bronchitis and 19 had chronic bronchitis and chronic obstructive pulmonary disease (COPD). Eighteen of the patients with bronchitis had recurrent infective exacerbations and 24 did not. Intrabronchial bacterial cultures were taken with a protected specimen brush. RESULTS: Increased activity of neutrophils, fibroblasts, and eosinophils was found in the patients with chronic bronchitis as assessed by the levels of myeloperoxidase (MPO) and interleukin-8 (IL-8), hyaluronan, and eosinophil cationic protein (ECP), respectively. The levels of tryptase did not differ from the controls. High correlations were found between the levels of MPO and IL-8, as well as ECP and IL-8. No differences were found between the patients with COPD and those with non-obstructive chronic bronchitis. CONCLUSIONS: Recruitment and activation of both neutrophils and eosinophils seem to be a characteristic of chronic bronchitis. This activation is associated with IL-8. The patients with intrabronchial cultures of Streptococcus pneumoniae had the highest individual levels of MPO, ECP, and IL-8 of all subjects in the study, indicating that colonisation with S pneumoniae could promote bronchial inflammation.

Adult↗

PubMed1995

Monocyte responsiveness and a T-cell subtype predict the effects induced by cotton dust exposure.

The aim of the study was to evaluate whether peripheral cellular parameters could predict susceptibility to decreased lung function and associated symptoms, in response to a single exposure to cotton dust. Previously nonexposed subjects (n = 42) inhaled an aerosol of cotton dust in a model cardroom during a period of 5 h. The subjects were examined before the exposure for FEV1, procoagulant activity (PCA) in blood mononuclear cells (BMNC), and serum IgE antibodies against a pool of inhalant antigens. Blood lymphocytes were typed into the helper/inducer (CD4+) and cytotoxic/suppressor (CD8+) T cells in combination with surface markers subdividing these populations. A questionnaire was used to identify atopic and nonatopic subjects. Immediately after exposure, the subjects were tested for FEV1 and PCA, and symptoms were recorded with a questionnaire. The dust exposure induced a decrease in FEV1 that was larger for the atopic group, but did not change the PCA in BMNC. The decrease in FEV1 was positively related to the preexposure PCA in both atopics and nonatopics. Symptoms from the airways after the exposure were reported to the same extent in the atopic and nonatopic group, and the subject group reporting chest tightness had a larger preexposure PCA. The atopic group had a larger proportion of blood CD8+ T lymphocytes negative for the monoclonal antibody anti-S6F1 (CD8+S6F1-), and in this group the decrease in FEV1 was significantly related to the proportion of this cell type. Also, in the atopic group, the proportion of CD8+S6F1- cells correlated positively with the preexposure PCA, and a negative correlation was found for this cell and serum levels of IgE.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

An echocardiographic evaluation of patients with idiopathic heart failure.

The primary myocardial disease idiopathic dilated cardiomyopathy (IDCM) is not clearly defined in the literature. The description is both morphologic and etiologic. We examined consecutive patients with congestive heart failure (CHF) of unknown cause to identify possible cases of IDCM and to give a detailed description of echocardiographic data and possible diastolic dysfunction in this group. The hospital records of patients aged 16 to 65 years hospitalized due to CHF or IDCM during a 6-year period (N = 2,711) were evaluated in a defined region of western Sweden. Twenty-two percent (584/2,711) of these records contained no plausible cause of CHF or IDCM, and among patients being alive, obvious cause was lacking in 411 of 1,516 (27%). These 411 patients were offered a diagnostic investigation, including echocardiography, and they were compared with a randomly selected control group (n = 103) from the general population. Of 411 patients, 293 accepted investigation. From the control group, we defined the reference level for left ventricular (LV) dilatation to be > 32 mm/m2, and reduced ejection fraction according to Teichholz formula to be < 50%. Applying these borderlines, we identified LV dilatation and systolic dysfunction to be present in 30%, either dilatation or systolic dysfunction in 36%, and neither in 34%. In patients without any signs of systolic dysfunction 44% (26/59) showed signs of diastolic dysfunction. In a multivariate analysis, LV dimension was not independently correlated to disease, although LV dimension was univariately correlated to ejection fraction (EF) (r = -0.59; p < 0.0001). However, EF (p < 0.0001), left atrial dimension (p < 0.0001), and the first third filling fraction (p < 0.0001) were the constellation of parameters that most accurately separated patients from controls. By using these three parameters, a positive and negative predictive accuracy of 98% and 61%, respectively, was achieved. Thus, in a consecutive group of patients with idiopathic CHF recruited from a nonselected group of hospitalized patients with CHF, all grades of ventricular function were found. In this group, 30% were identified as having IDCM. We give reference values for the diagnosis of idiopathic IDCM and a simple tool to identify patients with systolic and diastolic dysfunction.

Adult↗

PubMed1995

Complete sequence of a 38.4-kb human cosmid insert containing the polymorphic marker DXS455 from Xq28.

The complete DNA sequence of a cosmid mapping to human Xq28 (DXS455) has been determined using a shotgun approach (genbank accession number: L31948). The cosmid insert is 38.4 kb in length, and contains several repetitive sequences, including a highly repetitive region located in a fragment previously shown to contain a polymorphic VNTR locus, as well as short di- and tri-nucleotide repeats. In addition to the previously known VNTR locus, a CA-repeat and an unusual 800-bp repetitive region have been found to be polymorphic. The repeated sequence mapping to the site of the VNTR locus spans 480 bp in the cosmid. In addition to several AT-dinucleotide stretches, this repeat has four copies of a 25 bp repeat unit and flanking sequences similar to this 25-mer. No expressed sequences have so far been identified in this cosmid.

Bacteriophage M13↗

PubMed1995

Implants for single-tooth replacement. A clinical and experimental study on the Brånemark CeraOne System.

The general aim of the thesis was to study single-tooth replacements with implants using a recently developed prosthodontic concept, CeraOne. More specifically, the aims were to present prosthodontic procedures and early clinical experiences of CeraOne, and to study the following: the acceptance and the rejection of referred patients, the mechanical strength of the complete implant post and of superstructures on the CeraOne abutment, the treatment outcome from an on-going prospective clinical investigation, the effect of guided tissue regeneration when using e-PTFE membranes in narrow alveolar ridges, and finally, the outcome from treatments by general practitioners (GPs) who had performed the complete care of the single-tooth patient. The acceptance and the rejection of patients were studied on 184 patients, and the conclusions were based on data from referral, case history, clinical examination, and therapy planning. External trauma, root fractures, and congenitally missing teeth were the main reasons for lost or missing teeth in referred patients, while anatomical limitations were the most frequent reasons for the rejections. The mechanical strength was determined after testing in an Instron universal testing machine. The abutment screw was shown to be the weakest link, while a satisfactory safety margin against fractures was observed for the metal-ceramic and the all-ceramic crowns. It was also shown that the all-ceramic ¿ crown could resist bending moments up to a level that was more than three times as high as the one at which the porcelain crown fractured. In the clinical prospective study, the results from treatments of 57 patients (65 implants) were reported after two years and from 34 patients (37 implants) after three years. Favourable survival rates were shown for the implants (97.3% at 3-4 years) and, as a mean, only a small bone loss around the implants and the adjacent teeth was observed. The conical implants, however, showed a higher degree of bone los in comparison to the other implants. The CeraOne prosthodontic concept was simple to sue because of prefabricated components, and favourable aesthetic and clinical short-term results were achieved. Problems of screw loosening and fistulas were avoided and the cementation of the crown and the subgingival placement of the abutment shoulder did not cause any soft tissue recession. Fifteen patients (20 implants) with a suspected need of guided tissue regeneration were selected for the study using e-PTFE membranes. After treatment and at the second stage surgery, it was shown that most of the primarily exposed implant surfaces at this time were covered by a newly formed tissue with signs of osteoid activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1995

High-dose chemotherapy with BEAC regimen and autologous bone marrow transplantation for intermediate grade and immunoblastic lymphoma: durable complete remissions, but a high rate of regimen-related toxicity.

Forty-eight adult patients with recurrent or refractory intermediate grade or immunoblastic lymphoma received high-dose carmustine (BCNU), etoposide, Ara C and cyclophosphamide (BEAC), followed by autologous bone marrow transplantation (BMT). Median follow-up is 906 days (range 613-2067 days). The complete remission rate was 42% and 22% had a partial response. Actuarial failure-free survival is 30% +/- 6.6%. Twenty one patients relapsed or progressed. Only one relapse occurred > 1 year after autologous BMT. Adverse prognostic factors for failure-free survival include high LDH at the time of autologous BMT, chemotherapy-refractory disease and multiple prior relapses. Patients with chemotherapy responsive first salvage (those achieving first CR only with salvage chemotherapy and those with first relapse, responding to salvage chemotherapy) had a failure-free survival of 52% +/- 10% vs 12% +/- 6% for those with more advanced disease. Of 13 patients who had no adverse factors, only two relapsed. Treatment-related mortality occurred in 23%, including infection (n = 4), cardiac toxicity (n = 4), pulmonary toxicity (n = 2) and hemorrhage (n = 1). Pulmonary toxicity was more common among patients who had received prior radiation-therapy to the chest. BEAC chemotherapy with autologous BMT is an effective but relatively toxic regimen for patients with relapsed or refractory lymphomas. The combination of chemotherapy-responsive disease after failure of one chemotherapy regimen and normal LDH identifies patients with a favorable prognosis. Alternative cytotoxic regimens require evaluation, with the goal of reducing treatment related mortality. More effective cytoreductive therapy is required for patient with poor prognostic features.

Adolescent↗

PubMed1995

Characterization of nine novel mutations in the CD40 ligand gene in patients with X-linked hyper IgM syndrome of various ancestry.

X-linked immunodeficiency with hyper-IgM (HIGMX-1) is a rare disorder caused by defective expression of the CD40 ligand (CD40L) by activated T lymphocytes, resulting in inefficient T-B cell cooperation and failure of B cells to undergo immunoglobulin isotype switch. In the present work, we describe nine patients of various ancestry who bear different mutations in the X chromosome-specific CD40L gene. Two of the mutations were nonsense mutations, one each resulting in premature stop codons at amino acid residues 39 and 140. Three patients had single point missense mutations, one each at codons 126, 140, and 144. Another patient had a 4-bp genomic deletion in exon 2, resulting in a frameshift and premature termination. Three patients showed insertions, one each of 1, 2, and 4 nt, probably because of polymerase slippage, resulting in frameshift mutation and premature termination. Overall, these observations confirm the heterogeneity of mutations in HIGMX-1. However, the identification of two patients whose mutation involves codon 140 (previously shown to be altered in two other unrelated subjects) suggests that this may be a hotspot of mutation in HIGMX-1. In two additional patients with clinical and immunological features indistinguishable from canonical HIGMX-1, no mutation was detected in the coding sequence, in the 5' flanking region, or in the 3' UTR.

Base Sequence↗

PubMed1995

Interferon-alpha and interleukin-2 as treatment for leukemia relapse after allogeneic bone marrow transplantation.

We treated 12 patients with leukemia relapse after allogenic bone marrow transplantation with a combination of interferon-alpha (IFN-alpha) ((2.5-5.0) x 10(6) u/m2 subcutaneously three times a week) and interleukin-2 (IL-2) ((1.8-3.6) x 10(6) IU/m2 subcutaneously five times a week) to determine the toxicity and efficacy of combination cytokine therapy in this setting. The median age of the patients was 39 years (range: 16-50). There were nine females and three males. The median time to relapse from BMT was 98 days (range: 0-963). At the time of relapse, six patients had AML, four patients had CML (two in blast crisis and two in chronic phase with clonal evolution), and one patient had lymphoblastic lymphoma. Combination cytokine therapy was started a median of 108 days post BMT (range: 37-2404). Nine patients treated at the higher dose level required a 50% dose reduction because of toxicity or GVHD (three CNS, two GVHD, one high fever, one diarrhoea with hypotension, and one pericarditis). At a lower dose level, 2 of 10 patients had their treatment discontinued because of toxicity or GVHD. Six patients developed clinical findings consistent with acute GVHD while on combination cytokine therapy. Two patients responded to combination cytokine therapy: one with CML and one with AML. Combination cytokine therapy is feasible in the setting of relapse post allogeneic BMT. The combination of IL-2 1.8 x 10(6) IU/m2 five times a week with IFN-2 2.5 x 10(6) U/m2 three times a week seems to be tolerable, and merits further study in this setting.

Acute Disease↗

PubMed1994

The endoplasmic reticulum-Golgi system is a major site of plastoquinone synthesis in spinach leaves.

Plastoquinone biosynthesis was recently found to be enriched in the microsomal fraction of spinach leaves. Since it is generally assumed that this lipid may predominantly be synthesized in the chloroplast envelope we have prepared total microsomes, containing both endoplasmic reticulum and Golgi membranes, and chloroplast envelopes. Marker enzymes and lipid content showed no significant cross-contamination. Nonaprenyl-2-methylquinol transferase, participating in plastoquinone synthesis, was found in the microsomes but was absent from the chloroplast envelopes and thylakoid membranes. Nonaprenyl-4-hydroxybenzoate transferase activity, an enzyme of ubiquinone biosynthetic system, in microsomes exceeded more than 10 times that found in chloroplast envelopes. The result indicates that in plants plastoquinone is synthesized in the endoplasmic reticulum-Golgi system and transported to the chloroplasts.

Alkyl and Aryl Transferases↗

PubMed1994

6,7,8,9-Tetrahydro-N,N-di-n-propyl-3H-benzindol-8-amines. Derivatives as potent and orally active serotonin 5-HT1A receptor agonists.

Derivatives and isosteric derivatives of the potent 5-HT1A agonist 8-(di-n-propylamino)-6,7,8,9- tetrahydro-3H-benz[e]indole-1-carbaldehyde (5) were prepared and evaluated in vivo and in vitro for serotonergic and dopaminergic activity. The 1-cyano analog 8 was found to be almost equipotent to 5 and the previously described 2-cyano derivative 6, while a 1-chloro and 1-(1,1,1-trifluoroethyl) substituent (9 and 10, respectively) formed less potent derivatives. The isosteric 6,7,8,9-tetrahydro-1H-benz[g]indoles 4 and 12-15 showed surprisingly low affinity or activity at both serotonergic and dopaminergic systems. The interpretations of these results by means of drug-receptor interactions at the 5-HT1A subtype are discussed. Compounds 6 and 8 were found to have high oral bioavailability in the rat (63% and 54%, respectively).

Animals↗

PubMed1994

Determination of aflatoxin Q1 in urine by automated immunoaffinity column clean-up and liquid chromatography.

A liquid chromatographic system with an automated clean-up procedure for aflatoxin Q1 in human urine is described. The samples were cleaned up by using immunoaffinity columns originally designed for aflatoxin M1. The chromatographic system was a C18 column with an acidic mobile phase of acetonitrile-water containing potassium bromide. Fluorescence detection (365/440 nm) of aflatoxin Q1 was enhanced by addition of bromine, using post-column derivatization, which was studied by factorial designs. Average recovery of aflatoxin Q1 in spiked 10-ml urine samples was 88% (R.S.D. = 6.4%) at a level of 50 pg/ml. The determination limit was 49.5 pg/ml urine.

Aflatoxin M1↗

PubMed1994

Adaptor-based uracil DNA glycosylase cloning simplifies shotgun library construction for large-scale sequencing.

An improved strategy for the preparation of libraries for the random sequencing of DNA is reported. The protocol is a modification of a previous adaptor-based strategy, and utilizes long (11 base) overhangs, which eliminates the unreliable step of vector-insert ligation. The random inserts are prepared by adaptor ligation, while the M13 vector is prepared as described for uracil DNA glycosylase (UDG) cloning of polymerase chain reaction (PCR) products, using PCR with uracil-containing primers, followed by UDG treatment to produce overhangs. This method has been found to reliably yield large numbers of clones. There is no background due to religation of the vector, and all clones contain inserts. In addition, the method is simple and suitable for export to other investigators. Libraries were constructed from cosmids containing human DNA and from human cDNAs in order to characterize a strategy for shotgun sequencing of multiple shorter fragments.

Base Sequence↗

PubMed1994

The intrinsic 22 kDa protein is a chlorophyll-binding subunit of photosystem II.

The intrinsic 22 kDa polypeptide associated with photosystem II (psbS protein) was found to be able to bind chlorophyll. Extraction of isolated photosystem II membranes with octyl-thioglucopyranoside, followed by repetitive electrophoresis under partially denaturing conditions gave only one green band. It contained both chlorophyll a and chlorophyll b, exhibited an absorption maximum at 674 nm and a 77 K fluorescence peak at 675 nm. The chlorophyll-protein band contained a single polypeptide of 22 kDa. Based on these results and on previous protein sequence comparisons, it is suggested that the psbS protein is a chlorophyll a/b binding polypeptide and should thus be denoted CP22.

Chlorophyll↗

PubMed1994

Subfractional analysis of cyanobacterial membranes and isolation of plasma membranes by aqueous polymer two-phase partitioning.

The present work demonstrates that partition in aqueous polymer two-phase systems offers a rapid method for separation and isolation of thylakoid, plasma, and outer membranes from cyanobacteria. Pure plasma membranes from Phormidium laminosum can be isolated by this method within 3 h, starting with total membranes obtained by French press treatment of the cyanobacterial cells. The isolated plasma membranes have a broad density profile, giving rise to three subpopulations. The main fraction has the same density as the abundant thylakoid membranes. This fraction has not been resolved in previous separations based on sucrose gradient centrifugation, which is the only method previously used for isolation of cyanobacterial plasma membranes. Another advantage of the aqueous polymer two-phase system is that it can handle large quantities of starting material, which is essential to obtain a satisfactory yield since plasma membranes constitute only a very small fraction of the total membrane content in a cyanobacterial cell. The isolation procedure results in a pure plasma membrane preparation with retained cytochrome c oxidase activity. The results also point to the possibility of a lateral heterogeneity in the organization of the cyanobacterial plasma membrane.

Cell Membrane↗

PubMed1994

Evaluation of the image quality of ink-jet printed paper copies of digital chest radiographs as compared with film: a receiver operating characteristic study.

Paper copies of digital radiographs printed with the continuous ink-jet technique have proved to be of a high enough quality for demonstration purposes. We present a study on the image quality of ink-jet printed paper copies of digital chest radiographs, based on receiver operating characteristic (ROC) analysis. Eighty-three digital radiographs of a chest phantom with simulated tumors in the mediastinum and right lung, derived from a computed radiography (CR) system were presented in two series of hard copies as ink-jet printed paper copies and as laser recorded film. The images, with a matrix of 1,760 x 2,140 pixels, were printed with a spatial resolution of 10 pixels/mm in the CR film recorder as well as in the ink-jet printer. On film, every image was recorded in two versions, one optimized for the mediastinum and one for the lungs. On paper, only one image was printed; this constituted an effort to optimize both the mediastinum and the lungs. The ink-jet printed images, printed on a matt coated paper, were viewed as on-sight images with reflected light. The examinations were reviewed by six radiologists, and ROC curves were constructed. No significant difference was found between the performance of film and that of ink-jet paper prints. Because the cost for a paper copy is only a tenth of that of film, remarkable cost reductions can be achieved by using the ink jet technique instead. Our results show that further quality studies of ink-jet printed images are worthwhile.

Copying Processes↗

PubMed1994

Improved exercise hemodynamic status in dilated cardiomyopathy after beta-adrenergic blockade treatment.

OBJECTIVES: This study was performed to investigate exercise hemodynamic status in a double-blind, placebo-controlled trial and was a substudy in the Metoprolol in Dilated Cardiomyopathy Trial. BACKGROUND: Previous open studies have shown beneficial effects on exercise hemodynamic status after beta-adrenergic blocking agent therapy in patients with congestive heart failure. METHODS: The study included 41 patients with idiopathic dilated cardiomyopathy with ejection fraction < 0.40 (metoprolol, 20 patients; placebo, 21 patients) whose hemodynamic status was investigated at rest and during supine submaximal exercise, at baseline and after 6 and 12 months of treatment. Myocardial metabolism was evaluated in a subset of 19 patients. RESULTS: Metoprolol-treated patients responded favorably, as expressed by improved exercise cardiac index ([mean +/- SD] placebo 4.8 +/- 1.6 to 4.7 +/- 1.8 liters/min per m2, metoprolol 4.3 +/- 1.1 to 5.4 +/- 1.9 liters/min per m2, p = 0.0001) and stroke work index (placebo 44 +/- 20 to 41 +/- 27 g.m/m2, metoprolol 35 +/- 16 to 58 +/- 28 g.m/m2, p < 0.0001). Exercise systolic arterial pressure increased (placebo 161 +/- 25 to 151 +/- 23 mm Hg, metoprolol 155 +/- 29 to 165 +/- 37 mm Hg, p = 0.0003) as well as exercise oxygen consumption index (placebo 463 +/- 194 to 474 +/- 232 ml/min per m2, metoprolol 406 +/- 272 to 507 +/- 298 ml/min per m2, p = 0.045). There was a significant increase in exercise duration in the metoprolol group (63 +/- 38 s) compared with the placebo group (-24 +/- 42 s) (p = 0.01). Net myocardial lactate extraction increased in the metoprolol group, suggesting less myocardial ischemia (placebo 17 +/- 22 to 9.5 +/- 6.4 mmol/min, metoprolol -32 +/- 100 to 42 +/- 45 mmol/min, p = 0.03). Peripheral levels of norepinephrine tended to decrease at rest and during exercise, whereas myocardial net spillover was unchanged. CONCLUSIONS: Metoprolol improved hemodynamic status in patients with dilated cardiomyopathy at rest and had a more pronounced effect during exercise. These positive effects were achieved along with improved or stable myocardial metabolic data.

Analysis of Variance↗