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Biomedical subjects

B Andersen

Publications and source records attributed to B Andersen.

At least 19 recordsLinked to original sources
PubMed1992

The PSI-E subunit of photosystem I binds ferredoxin:NADP+ oxidoreductase.

A photosystem I complex containing the polypeptides PSI-A to PSI-L, light-harvesting complex I and ferredoxin:NADP+ oxidoreductase has been isolated from barley using the non-ionic detergent n-decyl-beta-D-maltopyranoside. The ratio between bound ferredoxin:NADP+ oxidoreductase and P700 is 0.4 +/- 0.2. The complex is highly active in catalyzing light-induced transfer of electrons from plastocyanin to NADP+ at rates of 280 +/- 150 and 1800 +/- 800 mumol NADPH/(mg chl.h), without and in the presence of saturating amounts of exogenously added ferredoxin:NADP+ oxidoreductase, respectively. Endogenously bound ferredoxin:NADP+ oxidoreductase interacts with the PSI-E subunit as demonstrated by cross-linking experiments using two different types of cross-linkers and identification of the products by Western blotting and the use of monospecific antibodies.

Cross-Linking Reagents↗
PubMed1992

Atmospheric deposition of trace elements around point sources and human health risk assessment. I: Impact zones near a source of lead emissions.

The deposition of lead was monitored over 8 years in the area around a car battery factory north of Copenhagen, Denmark. The area also has heavy traffic. Deposition was measured by in-situ grown vegetables, transplant grass culture biomonitors, bulk deposition and soil samples. Three impact zones were identified by a multivariate statistical analysis. Within each zone, the total dietary intake of lead was estimated for adults and children as a percentage of the provisional tolerably weekly intake (PTWI), and as a result recommendation on restrictions in use of locally grown fruit and vegetables were given to the public. The pattern of lead deposition in the area during the period 1981-1988 was monitored and the amount of lead ingested via vegetables was toxically evaluated. Lead emission reduction measures introduced in the factory and in the traffic during the period produced significant reductions in lead deposition.

Adolescent↗
PubMed1992

A double-blinded multicenter trial of somatostatin in the treatment of acute pancreatitis.

To evaluate the effect of somatostatin in the treatment of acute pancreatitis, 63 patients were randomly allocated to continuous intravenous infusion for three days of 250 micrograms of somatostatin (Dura Scan, Odense, Denmark) per hour (n = 33), or placebo (n = 30). Patients with a first attack of pancreatitis, serum amylase level of more than 450 units per liter and symptoms for less than 24 hours were eligible for participation in the study. Apart from a slightly significant faster decrease in serum amylase concentrations, we were unable to demonstrate any significant benefit from somatostatin with regard to paraclinical values and clinical course.

Acute Disease↗
PubMed1992

Morbidity after immediate and delayed opening of sigmoid end colostomy: a randomised trial.

OBJECTIVE: To see if sigmoid end colostomies that were opened immediately carried a higher early morbidity than those in which opening was delayed for 10 days. DESIGN: Randomised trial. SETTING: University department of surgical gastroenterology. SUBJECTS: All patients for whom a temporary or permanent end sigmoid colostomy was done between December 1986 and May 1989. INTERVENTIONS: 51 patients had their colostomies opened immediately, and in 49 opening was delayed. MAIN OUTCOME MEASURES: Presence of ischaemia, retraction, separation or infection, and length of stay in hospital. RESULTS: Two patients from each group died within the first week; none of the deaths was associated with complications of the colostomy. One patient whose colostomy had been opened immediately developed gangrene of the stoma, and one in whom the opening had been delayed developed retraction. There was no difference between the groups in length of stay in hospital. CONCLUSION: As we could find no differences in morbidity whether the colostomy was opened immediately or whether it was delayed, we now recommend that it should be done immediately. The question of late complications (stenosis and hernia), however, cannot be answered yet.

Cause of Death↗
PubMed1991

RXR beta: a coregulator that enhances binding of retinoic acid, thyroid hormone, and vitamin D receptors to their cognate response elements.

The retinoic acid receptor (RAR) requires coregulators to bind effectively to response elements in target genes. A strategy of sequential screening of expression libraries with a retinoic acid response element and RAR identified a cDNA encoding a coregulator highly related to RXR alpha. This protein, termed RXR beta, forms heterodimers with RAR, preferentially increasing its DNA binding and transcriptional activity on promoters containing retinoic acid, but not thyroid hormone or vitamin D, response elements. Remarkably, RXR beta also heterodimerizes with the thyroid hormone and vitamin D receptors, increasing both DNA binding and transcriptional function on their respective response elements. RXR alpha also forms heterodimers with these receptors. These observations suggest that retinoid X receptors meet the criteria for biochemically characterized cellular coregulators and serve to selectively target the high affinity binding of retinoic acid, thyroid hormone, and vitamin D receptors to their cognate DNA response elements.

Amino Acid Sequence↗
PubMed1991

Consistent production of phenolic compounds by Penicillium brevicompactum for chemotaxonomic characterization.

A consistently produced group of fungal secondary metabolites from Penicillium brevicompactum has been purified and identified as the Raistrick phenols. These compounds are shown to exist separately as an equilibrium mixture in aqueous solutions. The Raistrick phenols have all been included in the metabolite profile of P. brevicompactum. By means of thin layer chromatography-scanning and high performance liquid chromatography-UV diode array detection, the chromatographic and spectroscopic data can be used in the chemotaxonomic characterization of the fungus.

Chromatography, High Pressure Liquid↗
PubMed1991

Pancreatic secretion of zinc and copper in normal subjects and in patients with chronic pancreatitis.

Pancreatic secretion of zinc and copper in duodenal juice were measured in 7 healthy persons and in 9 patients with chronic pancreatitis. Stimulation with cholecystokinin and secretin increased secretion of zinc in healthy persons but not in patients. Copper secretion was not influenced. In patients with chronic pancreatitis, the correlations between zinc secretion, and amylase and trypsin secretion were significant while in healthy subjects they were not. Possibly pancreatic zinc secretion in the duodenal juice might be used as a measure of exogenic pancreatic function, and determination of zinc in duodenal juice may replace enzyme determinations in the diagnosis of chronic pancreatitis.

Adult↗
PubMed1991

Estradiol inhibits transcription of the human glycoprotein hormone alpha-subunit gene despite the absence of a high affinity binding site for estrogen receptor.

Chronic administration of estradiol inhibits transcription of the gene encoding the alpha-subunit of pituitary glycoprotein hormones. Here, we show, using transfection analyses and a filter binding assay, that 1500 basepairs of proximal 5' flanking sequence of the human alpha-subunit gene lack a functional estrogen response element when transfected into heterologous cell lines, and fail to bind estrogen receptor purified from calf uterus. Yet, this same region of the alpha-subunit gene confers estradiol responsiveness (transcriptional suppression) to the bacterial chloramphenicol acetyltransferase gene in transgenic mice. A smaller promoter fragment of the bovine alpha-subunit gene also confers responsiveness to estradiol in transgenic mice, suggesting that the same element may mediate the steroid responsiveness of both promoters. Furthermore, regulation by estradiol of the chimeric human or bovine alpha-chloramphenicol acetyltransferase genes is pituitary specific, underscoring the physiological significance of these studies. Based on these results, we conclude that estradiol regulates expression of the alpha-subunit gene in vivo through a mechanism that does not involve high affinity binding of estrogen receptor to the alpha-subunit gene. Whether this mechanism is manifest at the level of the pituitary or hypothalamus remains to be determined.

Animals↗
PubMed1991

The effect of the benzodiazepine antagonist flumazenil on the sequels of diazepam given before upper gastrointestinal endoscopy. A double-blind randomized trial.

The prolonged sedation of benzodiazepines may be inconvenient for the patient. Reversal of sedation, therefore, would be desirable. Accordingly, we assessed the efficacy of the benzodiazepine antagonist flumazenil in a placebo-controlled randomized trial including 40 adults undergoing upper gastrointestinal endoscopy under diazepam (Diazemuls) sedation. We found no significant differences between groups with regard to either performance (two tests) or duration (within 240 min) of sedation. There were no noticeable side effects.

Adult↗
PubMed1991

Surgical treatment of morbid obesity. A survey of overall outcome 1968-1989.

This survey evaluates benefits and costs from a policy of employing surgical treatment in selected cases of morbid obesity. Between 1968 and 1978, we used end-to-side jejunoileal bypass. Despite many satisfied patients, complications were frequent and severe. For the next decade, we employed various types of gastric surgery. We eventually assessed a gastric balloon, but without success. Median duration of follow-up was 132 months in 145 patients with jejunoileostomy, 103 months in seven gastric bypass patients, and 36 months in 108 gastroplasty patients. Three patients were lost to follow-up. There have been four deaths after intestinal shunt and one after gastroplasty. The median re-admission rate was 1.6 per patient, while the median number of re-operations was 2.0 after intestinal shunt and 0.8 after gastric interventions. The median weight loss in our 260 patients was 32.1% of the preoperative weight. Outcome was good in 38.8%, acceptable in 40.4% and poor in 11.5% while there were 9.2% failures. Truly satisfactory outcomes, however, were rare, owing possibly to a negative relationship between weight loss and complications. Only 8.8% have obtained a stable normal weight without any side-effects.

Female↗
PubMed1990

A cis-acting element located between the cAMP response elements and CCAAT box augments cell-specific expression of the glycoprotein hormone alpha subunit gene.

Several cis-acting elements interact through their cognate trans-acting factors to confer placenta-specific expression to the alpha subunit gene of glycoprotein hormones. These elements include two tandemly arranged cAMP response elements (CREs, located between base pairs (bp) -146 and -111 relative to the transcription start site), an upstream regulatory element (URE, located between -180 and -150), and a CCAAT box (located between bp -100 and -80). Here, we identify a new regulatory region, junctional regulatory element (JRE), with critical nucleotides located between the CREs and CCAAT box (bp -120 to -100). Although the binding site of the JRE abuts the 3' CRE, methylation interference assays indicate that no overlap occurs between the contact points of the proteins that bind to the JRE and CRE. This new regulatory element is highly conserved across species and contains a palindromic binding site for a 50-kDa nuclear factor(s) which is distinct from the factors that bind the URE, CRE, and CCAAT box of the alpha subunit gene. Finally, gene transfer studies suggest that, although JRE binding activity is found in several cell types, this element acts relatively cell-specifically. We conclude that this element and its cognate trans-acting factor act in conjunction with the complexes formed over the URE, CREs, and CCAAT box to enhance the placenta-specific activity of the alpha subunit promoter.

Base Sequence↗
PubMed1990

The human alpha subunit glycoprotein hormone gene utilizes a unique CCAAT binding factor.

Placenta-specific expression of the gene encoding the alpha subunit of glycoprotein hormones involves the interaction of at least two different cis-acting elements: the upstream regulatory element (URE), which binds a placenta-specific trans-acting factor; and two tandem cAMP-response elements (CREs), which bind a ubiquitous protein (CRE-binding protein). To identify additional elements required for promoter activity, we used block replacement mutagenesis to produce a series of 10-base pair transversion mutations throughout the proximal promoter-regulatory region of the human alpha subunit gene. Transient expression of these constructs in choriocarcinoma cells enabled the identification of several closely spaced transcriptional control elements in addition to the previously identified URE and CREs. Gel mobility shift assays, methylation interference analyses, and UV cross-linking permitted identification of a factor that binds specifically to a canonical CCAAT box contained within the proximal promoter-regulatory of the human alpha subunit gene. This factor, which we refer to as alpha subunit CCAAT-binding factor (alpha CBF), is found in a variety of cell types and appears to be distinct from the previously characterized CCAAT-binding factors CTF/NF1, C/EBP, CP1, and NF-Y. We suggest that interaction of alpha CBF with factors binding to the URE and CREs may be required for maximal activity of the alpha subunit promoter in placental cells.

Base Sequence↗
PubMed1990

Bromazepam in generalized anxiety. Randomized, multi-practice comparisons with both chlorprothixene and placebo.

Bromazepam was compared with placebo and with chlorprothixene in a randomized, double-blind group-comparative multicenter trial in general practice. Two hundred and forty-five patients with generalized anxiety disorder (DSM-III 1980) were treated for 2 weeks with two daily doses of bromazepam, 3 mg or chlorprothixene, 15 mg or placebo. Median reductions in Hamilton Anxiety rating were 12 (bromazepam), 10.3 (chlorprothixene) and 7.3 (placebo). The study revealed significant superiority of bromazepam over placebo (median differences 3.3, 95% confidence limits: 0.3 and 6.1) but not over chlorprothixene (median difference 1.4, 95% confidence limits -0.8 and +3.5). Significantly higher rates of tiredness, sedation and hypersomnia were found on bromazepam and chlorprothixene compared to placebo. Tolerance was rated as "at least good" in 85.6% on bromazepam, in 86% on chlorprothixene and in 87.8% on placebo. Neither previous psychopharmacological treatment nor presence of psychosocial stress were of perceptible influence. Bromazepam and chlorprothixene are both superior to placebo in generalized anxiety states treated in general practice, but spontaneous improvements/placebo effects are substantial.

Adolescent↗
PubMed1990

Effects of beta-carotene repletion on beta-carotene absorption, lipid peroxidation, and neutrophil superoxide formation in young men.

The chemopreventive effects of beta-carotene are usually attributed to its antioxidant properties. To determine the effects of beta-carotene supplementation on different parameters of oxidative metabolism, 15 normal young male subjects (18-30 yrs) were placed on a carotenoid-free liquid diet for two weeks prior to entry into the study. Blood was then measured for five carotenoids, retinol, retinyl palmitate, retinol-binding protein, alpha-tocopherol, vitamin C, zinc, lipid peroxides, and neutrophil superoxide production. Absorption tests were performed with 15 mg of beta-carotene to determine absorption curves for each subject. Subjects were then divided into two groups and given either 15 (n = 7) or 120 (n = 8) mg of beta-carotene daily for four weeks along with the same carotenoid-free liquid diet. The absorption test and the blood measurements were repeated. After repletion with beta-carotene, serum lipid peroxide levels decreased in both groups (p less than 0.05), but no other changes were noted in either the neutrophil superoxide production or in the levels of any of the vitamins measured. In contrast to vitamin E, the superoxide scavenging ability of beta-carotene apparently does not contribute to its effects in lowering serum lipid peroxide levels.

Absorption↗