Density-matrix-functional calculations for matter in strong magnetic fields: Ground states of heavy atoms.
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Journal Article↗
Biomedical subjects
K Johnsen
Publications and source records attributed to K Johnsen.
Phenotypic and genotypic characterization of phenanthrene-degrading fluorescent Pseudomonas biovars.
A total of 41 phenanthrene degraders were isolated from a former coal gasification site by using Pseudomonas-selective Gould's S1 medium. All isolates were found to belong to the fluorescent Pseudomonas group and were subjected to characterization by phenotypic methods, including classical taxonomic tests, API 20NE, and Biolog GN, and the strains were further characterized by the genotypic method repetitive extragenic palindromic PCR (REP-PCR). By using classical tests, the population was found to consist of 38 strains belonging to P. fluorescens, 2 P. putida strains, and 1 Pseudomonas sp. Bacteria in phenograms from Biolog GN and REP-PCR data were divided into groups, which were in good agreement with classical test and API 20NE results. We found a nonfluorescent group of 22 bacteria inconsistent with any Pseudomonas sp. in Bergey's Manual of Systematic Bacteriology. The group showed small differences in the genotypic test, indicating that all 22 isolates were not recent clones of the same isolate. Analyses of the nonfluorescent group indicated that it belonged to Pseudomonas, but the group could not be affiliated with P. fluorescens because of differences in DNA-DNA hybridization. Identifications using classical tests and API 20NE were found to correlate, but Biolog GN identifications after 24-h incubation resulted very often in the distantly related P. corrugata. The reproducibilities of individual tests of each phenotypic method were assessed, and low reproducibilities were mainly found to be associated with specific Biolog GN test wells. Classical tests and API 20NE proved to be the best for identification of isolates, whereas Biolog GN and REP-PCR were found to be the best tests for high resolution among these closely related isolates.
Bacterial Typing Techniques↗
D175 discriminates between NADH and NADPH in the coenzyme binding site of Lactobacillus delbrueckii subsp. bulgaricus D-lactate dehydrogenase.
The NAD-dependent D-(-)-lactate dehydrogenase (D-LDH) from Lactobacillus delbrueckii subsp. bulgaricus (in short, L. bulgaricus) has been modified at position 175 by site-directed mutagenesis, changing a conserved aspartate residue into an alanine. The D175A mutant enzyme displays a 40-fold shift in coenzyme preference from NADH to NADPH. This demonstrates that D175 truly belongs to the amino acid consensus GXGXXGX(17)D (where X represents any residue) which is the signature of the coenzyme binding site of most NAD-dependent dehydrogenases.
Alanine↗
[Night calls for general practitioners].
We examined night calls in each of four rural Norwegian municipalities with 6,000-7,000 inhabitants during three months in winter 1992/1993. Most out-of-hours calls were covered by general practitioners on rota. The overall rate of night calls (2300-0700) was 55 per 1,000 inhabitants per year, varying from 39 to 77 in the municipalities (p < 0.01). In 42% of the night calls the patient was advised over the telephone, 23% were seen in the surgery and 34% were visited at home. We found a higher rate of night calls in our material than found in previous studies on the subject. We assume that this difference in the number of night calls can be explained to some extent by the different attitudes signalled by the doctors to their patient populations.
Adolescent↗
NAD(+)-dependent D-2-hydroxyisocaproate dehydrogenase of Lactobacillus delbrueckii subsp. bulgaricus. Gene cloning and enzyme characterization.
A genomic library from Lactobacillus delbrueckii subsp. bulgaricus was used to complement an Escherichia coli mutant strain deficient for both lactate dehydrogenase and pyruvate formate lyase, and thus unable to grow anaerobically. One recombinant clone was found to display a broad specificity NAD(+)-dependent D-2-hydroxyacid dehydrogenase activity. The corresponding gene (named hdhD) was subcloned and sequenced. The deduced amino acid sequence of the encoded enzyme indicates a 333-residue protein closely related to D-2-hydroxyisocaproate (i.e. 2-hydroxy-4-methyl-pentanoate) dehydrogenase (D-HO-HxoDH) of Lactobacillus casei and other NAD(+)-dependent D-lactate dehydrogenases (D-LDH) from several other bacterial species. The hdhD gene was overexpressed under the control of the lambda phage PL promoter and the enzyme was purified with a two-step method. The L. delbrueckii subsp. bulgaricus enzyme, like that of L. casei, was shown to be active on a wide variety of 2-oxoacid substrates except those having a branched beta-carbon.
Alcohol Oxidoreductases↗
Interethnic difference in thiopurine methyltransferase activity.
A number of metabolic pathways are subject to both genetic polymorphism and interethnic differences. A catabolic pathway of 6-mercaptopurine, red blood cell (RBC) thiopurine methyltransferase (TPMT) activity showed genetic polymorphism in Caucasians, but variation according to ethnicity has not been studied. We investigated if red blood cell thiopurine methyltransferase was subject to interethnic variation in a Saami (Lappish; n = 36) and a Caucasian population (n = 50). The Saami population sample had 29% higher thiopurine methyltransferase activity, 17.0 +/- 3.3 U/ml red blood cell compared with the Caucasian population sample, 13.1 +/- 2.9 U/ml red blood cell (p much less than 0.001). Probit plots and frequency distribution histograms supported bimodality consistent with genetic polymorphism in both study populations. Differences in chronic diseases, drug consumption, age, or gender could not explain the interethnic difference in red blood cell thiopurine methyltransferase activity. The higher red blood cell thiopurine methyltransferase activity in the Saami population group indicates that these subjects may require higher dosages of thiopurine drugs than Caucasians.
Adolescent↗
The prevalence of ankylosing spondylitis among Norwegian Samis (Lapps).
A population survey of the Sami (Lapp) population of the municipalities Karasjok and Kautokeino in north Norway revealed a prevalence of ankylosing spondylitis (AS) according to the New York criteria of 1.8%. Eleven cases of AS were found, 7 men and 4 women. Only 4 of the 11 observed cases of AS were aware of the diagnosis of AS prior to the survey. Ten of 11 patients with AS possessed HLA-B27 (91%) which is found in 24% of the general Sami population in this area. It was calculated that 6.8% of B27 positive persons had AS.
Adult↗
High serum selenium concentrations in reindeer breeding Lappish men.
This study investigated the relationship of serum selenium to its dietary sources in a group of Lappish men and a control population. Lappish men had higher serum selenium concentrations than non-Lappish men (1.79 vs 1.58 mumol/1; p = 0.003). Serum selenium correlated positively with consumption of reindeer meat, age and cholesterol. In linear regression models, however, being Lappish was the most significant predictor of high serum selenium. Lappish men ate more reindeer meat (p = 0.001) and less fish (p = 0.013) than men in the control group. Consumption of reindeer meat was also correlated with higher serum cholesterol levels. We conclude that high serum selenium concentrations in Lappish men may be important since low mortality from cancer is reported in this group.
Adult↗
Benign meningococcemia with IgG and IgM antimeningococcal antibodies measured by ELISA.
Six patients with benign meningococcemia are presented. The clinical picture was typically intermittent fever with chills, skin eruptions, maculopapules (often hemorrhagic) and arthritis/arthralgia in a person in good general condition. Meningococci of serogroup B were isolated from the blood of 3 patients, from the cerebrospinal fluid of 1 patient and from the nasopharynx of the remaining 2 patients. In 4 patients we assayed the levels of IgG and IgM antibodies against meningococcus serogroup B in an enzyme-linked immunosorbent test (ELISA), using whole bacteria as the antigen. All of them had higher antibody levels than the geometric means for healthy controls of both IgG and IgM, except for 1 patient who did not develop IgG antibodies.
Adolescent↗
[Control of cardiac function during therapy with doxorubicin and other anthracyclines].
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Antibiotics, Antineoplastic↗
Cimetidine, 800 mg at night, in the treatment of duodenal ulcers.
One hundred and eight patients with endoscopically proven duodenal ulcers were randomly allocated to treatment with cimetidine, either 400 mg twice daily or 800 mg at night for 4 to 8 weeks in a double-blind study. There was no significant difference between the healing rates of the two groups. Thus, 45 of 52 (87%) healed on cimetidine twice daily and 43 of 51 (84%) healed on 800 mg at night after 4 weeks' treatment. The corresponding healing rates after 8 weeks were 51 of 52 (98%) and 50 of 51 (98%). The intensity of pain decreased more rapidly in the group treated with 800 mg cimetidine at night. These results indicate that 800 mg cimetidine at night is as good as 400 mg given twice daily.
Adolescent↗
[Typhlitis in acute leukemia].
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Abdomen, Acute↗
HLA-B27-negative arthritis related to Campylobacter jejuni enteritis in three children and two adults.
Five out of 37 patients with proven Campylobacter jejuni enteritis developed arthritis. Two adult patients presented with classical Reiter's syndrome. One of the three children had reactive arthritis, and clinical suspicion of septic arthritis could not be confirmed in two. The acute synovitis subsided usually without treatment in all patients within 3-7 days, while arthralgia persisted longer in 4 patients. HLA-B27 was not present in the 5 patients with arthritis, but was found in 4 others. In Northern Norway, Campylobacter fetus ssp. jejuni is more frequently isolated from stool specimens than Salmonella, Shigella and Yersinia enterocolitica. Synovial fluid should be cultured following Campylobacter jejuni enteritis in arthritis patients.
Adolescent↗
[Drug interaction during therapy with tolbutamide. The influence of some commonly used drugs on plasma level and half life in diabetic out-patients (author's transl)].
Tolbutamide belongs to those drugs responsible for the majority of drug interactions. E.g. Tolbutamide metabolism has been shown to be inhibited by coumarole derivatives. We determined plasma-tolbutamide levels in diabetic out-patients for one year. The results obtained indicate no difference in patients additionally treated with either digoxin or digoxin and alpha-methyldopa, or buformin and phenprocumone as compared with control groups. Interactions with respect to biotransformation should not be expected as far as digoxin, alpha-Methyldopa, or buformine were concerned, since these compounds do not share a common metabolic pathway with tolbutamide. In a different group of patients the elimination half life of tolbutamide under the influence of phenprocoumone was additonally determined. Differences could not be detected. This finding can be explained by means of enzyme-kinetic considerations, since phenprocumone, in contrast to dicoumarole, becomes metabolized according to a first order reaction. Competitive enzyme inhibition with tolbutamide which is metabolized similarly to phenprocoumone, therefore appears improbable.
Buformin↗
[Conditions for the occurrence of drug interactions during biotransformation].
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Biotransformation↗
Reevaluation of the mode of action of streptolydigin in Escherichia coli: induction of transcription termination in vivo.
Growth of the permeable strain AS19 of Escherichia coli B is more sensitive to the antibiotic streptolydigin than is in vitro ribonucleic acid (RNA) synthesis. The in vivo chain elongation rates of lacZ messenger RNA and ribosomal RNA are not affected at 1.5 x 10(-6) M, a concentration that reduces the growth rate threefold. The synthesis of large proteins is inhibited preferentially, and a considerable fraction of the polypeptides synthesized is unstable. The synthesis of complete beta-galactosidase is inhibited relative to the synthesis of short, unstable polypeptides, which include the first 60 to 70 amino acids of beta-galactosidase. The expression of the following polycistronic transcription units is strongly biased against promoter-distal genes: trp, deo, rpoBC, and rrn. The extent of polarity is proportional to the distance transcribed and to the streptolydigin concentration. Streptolydigin appears to destabilize active transcription complexes irreversibly irrespective of the type of transcript (messenger RNA, ribosomal RNA) and of transcription intensity. We suggest that streptolydigin leads to premature termination of transcription, resulting in release of incomplete transcripts and, thus, a decrease in overall messenger RNA concentration, which becomes limiting for protein synthesis, i.e., for growth.
Aminoglycosides↗
Control of protein synthesis in Escherichia coli: analysis of an energy source shift-down.
The energy source shift-down described in the preceding paper (Molin et al., J. Bacteriol. 131: 7-17, 1977) was used to study the effects of shift-down on protein synthesis. The overall rate of protein synthesis was reduced immediately, and to the same extent, in stringent and relaxed strains. The primary effect of the shift was a slowing down of the polypeptide chain growth rate, a finding not previously reported. In stringent strains the normal, preshift rate was reestablished within 2 to 3 min, whereas in relaxed strains the chain growth rate remained low for about 20 min before slowly returning to the normal value, which was reestablished some 50 to 60 min after the shift. Throughout this transition, the stability of messenger ribonucleic acid (mRNA) remained unchanged in both strains. We interpret these findings as evidence of the more rapid reduction of the mRNA pool in the stringent strain after shift-down: we believe that very soon after the shift, the stringent strain reduces its pool of mRNA and with it the number of ribosomes engaged in protein synthesis. In this manner the number of active ribosomes is adjusted to the availability of energy and carbon. The relaxed strain cannot rapidly reduce its mRNA pool, which thus remains large enough to engage a near-preshift number of ribosomes during a prolonged period; as a consequence its ribosomes must work at a reduced rate. The possibility that ppGpp is involved in the control of mRNA production is discussed. After shift-down, the initial part of beta-galactosidase (the auto-alpha fragment) was produced at a higher rate than complete beta-galactosidase in the relaxed strain, as expected when translation is impeded.
Bacterial Proteins↗
Interaction of pentobarbital, diphenylhydantoin and digitoxin with ethanol in the isolated perfused guinea-pig liver.
In the isolated guinea-pig liver the interactions of ethanol with the metabolism of three drugs (14C-pentobarbital, 14C-diphenylhydantoin, and 2H-digitoxin) has been investigated. The disappearance of ethanol could be described by zero-order kinetics and was not influenced by the three drugs. In the case of 14C-pentobarbital and 14C-diphenylhydantoin after a short period of distribution disappearance of radioactivity was faster under the influence of ethanol, whereas radioactivity in liver tissue was increased. The radioactivity accumulated in the liver tissue predominantly represented the unchanged drugs suggesting that the inhibition of drug metabolism by ethanol was the cause of the altered distribution. In the case of 3H-digitoxin ethanol did neither significantly influence the distribution of radioactivity nor the pronounced biliary excretion. However there exists some evidence for a minor inhibition of 3H-digitoxin's metabolism by ethanol.
Animals↗