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J S Andersen

Publications and source records attributed to J S Andersen.

At least 55 records · Page 3Linked to original sources
PubMed1995

Evaluation of mass spectrometric techniques for characterization of engineered proteins.

Mass spectrometric characterization of engineered proteins has been examined using bovine recombinant Acyl-CoA-Binding Protein (rACBP), [15N]-labeled rACBP, and a number of sequence variants of ACBP produced by site-directed mutagenesis. The mass spectrometric techniques include ESIMS and MALDIMS for analysis of the intact protein. Peptide maps have been obtained either by direct analysis of enzymatically derived mixtures by PDMS, ESIMS, and MALDIMS or by off- and on-line HPLC-mass spectrometry. ESIMS was found to be most accurate for analysis of intact proteins. The best sequence coverage in mapping was obtained by LC-ESIMS and by direct mixture analysis by MALDIMS. The latter technique was favorable in terms of sensitivity and speed. A general strategy for mass spectrometric characterization of engineered proteins is suggested.

Amino Acid Sequence↗
PubMed1994

[Diagnosis of sore throat. A multipractice study of 3 different ways of antigenic determination for detection of group A streptococci in throat swabs].

During five months in the winter of 1992/1993, 34 general practitioners (GPs) from 18 offices participated in a clinical testing of three group A streptococcal antigen detection test (ADT) kits (Abbott TestPack Strep A Plus (Abbott), Concise Strep A, Hybritech (Concise) and Kodak SureCell Strep A (Kodak)). The GPs obtained duplicate throat swabs, one for processing with the ADT kit, the other for culture reference at The Streptococcus Laboratory (Bacteriological Department, Statens Seruminstitut, Copenhagen). A total of 1389 patients were enrolled in the study, thirty percent of whom were infected by group A streptococci. The following results were obtained: Abbott: Sensitivity: 76%, specificity: 99%, positive predictive value: 97%, negative predictive value: 91%. Concise: Sensitivity: 82%, specificity: 95%, positive predictive value: 86%, negative predictive value: 92%. Kodak: Sensitivity: 84%, specificity: 87%, positive predictive value: 73%, negative predictive value: 93%. As a follow-up to the main study, each GP filled in a questionnaire, stating his opinion about the investigated ADT kit. Considering the practical handiness, Concise scored higher than Abbott, which in turn scored higher than Kodak. In conclusion, Abbott and Concise are recommended for the diagnosis of group A streptococcal pharyngotonsillitis in general practice.

Antigens, Bacterial↗
PubMed1994

Yeast acyl-CoA-binding protein: acyl-CoA-binding affinity and effect on intracellular acyl-CoA pool size.

Acyl-CoA-binding protein (ACBP) is a 10 kDa protein characterized in vertebrates. We have isolated two ACBP homologues from the yeast Saccharomyces carlsbergensis, named yeast ACBP types 1 and 2. Both proteins contain 86 amino acid residues and are identical except for four conservative substitutions. In comparison with human ACBP, yeast ACBPs exhibit 48% (type 1) and 49% (type 2) conservation of amino acid residues. The amino acid sequence of S. carlsbergensis ACBP type 1 was found to be identical with the one ACBP present in Saccharomyces cerevisiae. A recombinant form of this protein was expressed in Escherichia coli and S. cerevisiae, purified, and its acyl-CoA-binding properties were characterized by isoelectric focusing and microcalorimetric analyses. The yeast ACBP was found to bind acyl-CoA esters with high affinity (Kd 0.55 x 10(-10) M). Overexpression of yeast ACBP in S. cerevisiae resulted in a significant expansion of the intracellular acyl-CoA pool. Finally, Southern-blotting analysis of the two genes encoding ACBP types 1 and 2 in S. carlsbergensis strongly indicated that this species is a hybrid between S. cerevisiae and Saccharomyces monacensis.

Acyl Coenzyme A↗
PubMed1994

The complete amino acid sequence and disulphide bond arrangement of oat alcohol-soluble avenin-3.

We have elucidated the complete amino acid sequence of one of the avenin components, avenin-3, isolated from oat (Avena sativa L.), variety Narymsky 943. The sequence of the protein was determined by sequencing of CNBr and trypsin-generated peptides in combination with mass spectrometry. The protein is a single polypeptide chain, consisting of 201 amino acid residues with M(r) 23,252.8. The N-terminal amino acid residue of the protein is blocked with 5-oxoproline (pyroglutamic acid). All eight cysteine residues in avenin-3 are involved in disulphide bonds. The positions of these bonds were established by identification of a CNBr cleavage product of the intact avenin containing all the disulfide bonds (S-S core). Subsequent subdigestion of this S-S core allowed isolation of disulphide bonded peptides detected by differential reverse-phase HPLC before and after reduction. As a result, all four disulphides Cys50 Cys183, Cys58 Cys77, Cys84 Cys85 and Cys97 Cys191 were identified. Comparison of avenins with other prolamins demonstrates a high degree of similarity, which is especially pronounced around the cysteine residues. Avenins differ slightly from other prolamins in having unique N-terminal sequences and some differences in the repeated sequence motifs.

Amino Acid Sequence↗
PubMed1994

Purification and characterization of a cadmium-induced metallothionein from the shore crab Carcinus maenas (L.).

Two metallothionein variants were purified from the midgut gland of crabs (Carcinus maenas) exposed to a high cadmium concentration (2 p.p.m.). One of the variants was purified from crabs exposed to a low cadmium concentration (0.5 p.p.m.). The purification method involved acetone precipitation, gel filtration and reversed-phase h.p.l.c. The complete amino acid sequences of both variants have been elucidated by m.s. and automated sequence analysis on S-methylated proteins or fragments produced by cleavage of the S-methylated proteins with Staphylococcus aureus proteinase. The two variants from crabs exposed to the high cadmium concentration differed only by a single residue of methionine at the N-terminus. The single variant isolated from crabs exposed to the low cadmium concentration was the one without the N-terminal methionine, indicating that high cadmium concentrations either inhibit the processing enzymes and/or that the processing enzymes cannot keep pace with the increased metallothionein synthesis when cadmium availability is high. Cadmium-induced metallothionein from C. maenas shows a high degree of structural similarity to metallothioneins from the decapod crustaceans Scylla serrata and Homarus americanus.

Amino Acid Sequence↗
PubMed1994

Localization of an O-glycosylated site in the recombinant barley alpha-amylase 1 produced in yeast and correction of the amino acid sequence using matrix-assisted laser desorption/ionization mass spectrometry of peptide mixtures.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of peptide mixtures was used to characterize recombinant barley alpha-amylase 1, produced in yeast. Three peptide mixtures were generated by cleavage with CNBr, digestion with endoproteinase Lys-C and Asp-N, respectively, and analyzed directly by MALDI-MS. Based on the three mass spectrometric peptide maps, an error in the sequence deduced from cDNA, resulting in a mass difference of 28 Da, was located to a sequence stretch of 5 amino acid residues; furthermore, a dihexose substituent was identified on Thr410. Subsequent Edman degradation of two selected peptides isolated from the endoproteinase Lys-C digest corrected the sequence to be Val instead of Ala in position 284 and confirmed the O-glycosylation. These results demonstrate that the direct peptide mixture analysis by MALDI-MS is a rapid and sensitive method for protein characterization and provides valuable information before further characterization.

Amino Acid Sequence↗
PubMed1994

Latency to rapid eye movement sleep as a predictor of treatment response to fluoxetine and placebo in nonpsychotic depressed outpatients.

Fluoxetine and placebo were compared in 89 outpatients with major depression with (n = 45) or without (n = 44) a reduced or shortened rapid eye movement latency (SREML) (< or = 65 minutes) to determine whether rapid eye movement latency (REML) predicted placebo and/or antidepressant response. Men and women were stratified based on polysomnographic recordings and then randomly assigned to receive double-blind fluoxetine (20 mg/day) or placebo for 8 weeks after a 2-week, single-blind, placebo lead-in period. Fluoxetine-treated patients demonstrated a significantly greater reduction in the Hamilton Rating Scale for Depression total score and a significantly greater response rate than placebo-treated patients in both the SREML and the combined strata. Treatment differences in the non-SREML stratum were not statistically significant. Results supported REML as a predictor of placebo nonresponse but did not predict a differential fluoxetine response in patients with SREML compared with patients without SREML.

Adolescent↗
PubMed1993

[When are young people awarded disability pensions for sociomedical indications? A study from the municipality of Copenhagen].

Since 1984 it has been possible in Denmark to receive disability pensions for combined social and health reasons. About 500 people under the age of 45 have been pensioned in this way every year in the municipality of Copenhagen. The records of 476 persons awarded pensions in 1989 were examined with the purpose of describing their social history and health and social status at the time of pensioning. There were more men (62%) than women (38%). One hundred and nine pensioners were under 35 years of age. Forty-one percent of the pensioners grew up in broken families, and 38% lived apart from their parents during childhood. Only one quarter had occupational training. The pensioners had on average been working for nine years. Nearly two-thirds had received social security for more than five years. Thirty percent had no flat of their own, and 76% were living alone. Rehabilitation was attempted in 53% of the cases. Of the men, 89% abused alcohol and/or drugs, of the women 63%. Twenty-six percent of the pensioners were opioid addicts. There was significant somatic disease in one-third of the cases. The social strain on the youngest pensioners (< 35 years old) was in many respects the worst. Disability pensioners for combined health and social reasons were characterized by underprivileged childhood, bad education and an early developed abuse of alcohol and drugs. If disability pensioning is to be avoided, the community must intervene much earlier in the social course. It is currently not realistic to abolish disability pensions for this group of people.

Adult↗
PubMed1993

Primary structure of a 14 kDa basic structural protein (Lm-76) from the cuticle of the migratory locust, Locusta migratoria.

The complete amino acid sequence of a 14 kDa structural protein (LM-76) isolated from pharate cuticle of the locust, Locusta migratoria, was determined by Edman degradation of the intact protein and enzymatically derived peptides. Plasma desorption and electrospray mass spectrometry was used as an integrated part of the structure determination. Protein Lm-76 has characteristics similar to proteins previously isolated from the pharate locust. The amino acid composition shows a high content of alanine (32%) and absence of the amino acids Glu, Cys, Met, Phe and Trp. The sequence has a central hydrophilic region surrounded by two hydrophobic regions with 7 repeats of a (Tyr)-Ala-Ala-Pro-Ala/Val motif. The conservation around the prolyl residues within this sequence motif is demonstrated for the hitherto sequenced presumptive exocuticle proteins from L. migratoria. The N-terminal region of protein Lm-76 is enriched in the amino acids Gly, Leu and Tyr located in the conserved sequence NH2-Gly-Tyr-Leu-Gly-Gly-(Tyr)-.

Amino Acid Sequence↗
PubMed1993

Electrospray mass spectrometry characterization of post-translational modifications of barley alpha-amylase 1 produced in yeast.

We have used electrospray mass spectrometry (ESMS) in combination with protein chemistry and genetics to delineate post-translational modifications in yeast of barley alpha-amylase 1 (AMY1), a 45 kD enzyme crucial for production of malt, an important starting material in the manufacture of beer and whisky. In addition to signal peptide processing these modifications are: (1) removal of C-terminal Arg-Ser by Kex1p, (2) glutathionylation of Cys95, (3) O-glycosylation, and (4) additional degradation of the C-terminus.

Base Sequence↗
PubMed1992

[Extent of HIV infection and AIDS among drug addicts].

The purpose of this study was to review the extent of the HIV-epidemic and to make a prognosis about the number of AIDS-cases among drug addicts in the community of Copenhagen. In the public institutions for treatment of drug addicts, 191 HIV-positive individuals were known by January 1991. In the period August 1990-November 1991, 33 newly recognized cases of seropositivity were registered among drug addicts in the area of Copenhagen, but the time of infection was unknown. By October 1991, 53 cases of AIDS among drug addicts in Denmark were recorded. Based upon the knowledge of incubation period and mortality of AIDS, it was possible to set up a mathematical model, from which the number of expected AIDS-cases could be estimated. This model showed that the number of living drug addicts with AIDS in the community of Copenhagen probably not will exceed 20 during the coming years. It was also showed, that the number of drug addicts, who were infected with HIV in the primary spread of the virus in 1985-1986, was probably lower than 250. The actual prevalence and incidence of HIV-infection among drug addicts is uncertain, and there is a need for better surveillance of the epidemic.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Renal function in patients with untreated acute myocardial infarction.

This study provides data on plasma volume (PV), extracellular volume (ECV) and renal function in 8 untreated patients with acute myocardial infarction (AMI). At day 2 and day 10 after AMI, glomerular filtration rate (GFR), urinary excretion rate of water (Vu), sodium clearance (CNa) and lithium clearance (CLi) were used for assessing reabsorption rates of sodium and water in proximal and distal nephron segments. PV and blood pressure at day 2 were not significantly different from values at day 10. Heart rate (HR), weight and ECV at day 2 were significantly increased when compared with values at day 10 (78 vs. 62 pr. min and 17.0 vs. 16.2 1, respectively). Plasma norepinephrine values were slightly elevated at day 2 and day 10. GFR was initially high and decreased from day 2 to day 10 (118 vs. 104 ml min-1) together with CLi and Ck. However, Vu, CNa and fractional excretion rate of sodium increased markedly from day 2 to day 10. The results suggest that sodium and water retention in the initial phase of AMI without left ventricular failure is due to an increase in tubular reabsorption in distal nephron segments mediated by mechanisms other than the sympathetic nervous system.

Absorption↗
PubMed1992

An evaluation of a commercial co-agglutination test for the diagnosis of group A streptococcal tonsillitis in a family practice.

The result of a rapid co-agglutination test was compared with the clinical diagnosis of group A streptococcal tonsillitis, a laboratory culture from the throat serving as the correct result. The study was carried out in a family practice, with two GPs partaking: it included 105 consecutive patients. The outcome of the rapid test was significantly correlated to the degree of growth determined by throat culture, and it was superior to the clinical judgement. The statistical analysis of the results of the rapid test revealed (95% confidence limits in brackets) a specificity of 97% (91-100), sensitivity of 68% (48-84), a positive predictive value of 90% (70-99), and a negative predictive value of 89% (81-95). Although the co-agglutination test was superior to the clinical diagnosis, the sensitivity of this test is rather low when compared with other recently evaluated rapid tests for use in family practice.

Adolescent↗
PubMed1991

Atrial fibrillation and left atrial enlargement: cause or effect?

In a blinded controlled study, 58 consecutive patients with definite left atrial enlargement (M-mode dimension of at least 45 mm) were followed up after 1-2 years. The aim of the study was to examine the following: (a) the prospective risk of developing atrial fibrillation (AF); and (b) the effect of the heart rhythm on the left atrial size. Of 36 patients in sinus rhythm, one developed paroxysmal AF and one developed persistent AF during a median follow-up period of 20 months. Thus the incidence of new AF was 5% per year. Eighteen patients died before scheduled echocardiographic follow-up, but in the remaining subjects the left atrial dimension did not change significantly: the median increment was 1 mm in 20 patients who sustained sinus rhythm vs 2 mm in 16 patients with chronic AF (P greater than 0.05). Although left atrial dilatation may cause AF and vice versa, this study demonstrated that the incidence of new AF is low, despite the fact that the left atrial dimension is substantially increased. Similarly, AF per se does not appear to have any major impact on the left atrial dimension.

Adult↗