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H Andersen

Publications and source records attributed to H Andersen.

At least 73 records · Page 4Linked to original sources
PubMed1988

The bimodal effect of interleukin 1 on rat pancreatic beta-cells--stimulation followed by inhibition--depends upon dose, duration of exposure, and ambient glucose concentration.

To investigate the hypothesis that interleukin 1 initially stimulates and then suppresses beta-cell function and that this sequential effect is directly related to interleukin 1 dose, duration of exposure, and ambient glucose concentration, insulin release was measured from cultured newborn rat islets exposed for 6 h to 6 days to interleukin 1 at doses ranging from 20 to 2000 ng/l at glucose concentrations of 3.3, 5.5 and 11 mmol/l. After 6 h of exposure and at all three glucose levels, all doses of interleukin 1 stimulated insulin release, maximal stimulation (370% of control) being observed at 5.5 mmol/l glucose and 100 ng/l interleukin 1. In contrast, after 6 days, all doses of interleukin 1 were inhibitory irrespective of glucose level, maximal inhibition (90%) being observed at 11 mmol/l glucose and 2000 ng/l interleukin 1. At 24 and 48 h of exposure, the biphasic effect of interleukin 1 was observed: lower doses of interleukin 1 at lower glucose concentrations at 24 h being more stimulatory with transition to inhibition directly related to higher glucose levels, higher interleukin 1 doses, and longer exposure. After 48 h, 200 ng/l of interleukin 1 increased insulin release to 220% at 3.3 mmol/l glucose, but at 11 mmol/l glucose a 60% suppression was seen. On the basis of these data we suggest that interleukin 1's effect on beta-cells is bimodal: stimulation followed by inhibition. Increasing interleukin 1 dose and ambient glucose concentration shift this response to the left. Experimental results will, and in vivo effects may, depend upon these three variables.

Animals↗
PubMed1987

Structure and accessibility of domain I of Escherichia coli 23 S RNA in free RNA, in the L24-RNA complex and in 50 S subunits. Implications for ribosomal assembly.

Domain I of 23 S RNA of Escherichia coli was probed in renatured RNA, in the protein L24-RNA complex and in 50 S subunits with ribonucleases specific for single- and double-stranded regions and with chemical reagents specific for guanosines (N-1 and N-2), adenosines (N-1, N-7 and N-6), cytidines (N-3) and uridines (N-3). Reactive sites were detected by a reverse transcriptase procedure. The results support most new features of the latest version of the Santa Cruz/Urbana model of the secondary structure, which is based on evidence from sequence comparison. Most double-helical segments were reactive to cobra venom ribonuclease to some degree; the exceptions were the five "long-range" helices that are probably compactly folded within the structure. The data provide evidence for the occurrence of A(syn) X G(anti) pairings in internal loops and at the ends of some helices; they also support the existence of extensive higher-order structuring, especially within the interhelical regions, and are compatible with two of three tertiary interactions in the free RNA that were predicted from comparative sequence studies. Protein L24 is the only primary binding protein that associates with domain I and it strongly protects two sites against ribonuclease and chemical activity. Site A has the properties of a classic protein binding site and we conclude from four lines of evidence that it is the primary attachment site. Site B is rich in highly conserved, unpaired adenosine residues and lies in a potentially critical region of the structure adjoining a group of long-range helices; we infer that L24 binding here is related to the important role of L24 in initiating ribosomal assembly; the existence of both sites is supported, independently, by genetic experiments. L24-induced enhanced reactivities were detected throughout the domain and are consistent with a general "tuning" of the RNA structure. The RNA domain in the 50 S subunits is almost completely resistant to ribonucleases and only a few sites, mainly interhelical, are accessible to chemical reagents. The appearance of several newly reactive nucleotides in the subunit RNA and the enhancement of some others suggest that some minor conformational changes occur on assembly. Nevertheless, the minimal secondary structure of the renatured RNA appears to be retained. We draw the general conclusion that domain I is a highly structured domain that is important for initiating assembly and for the subsequent organization of the ribosome.

Binding Sites↗
PubMed1987

Electrophoretic analysis of proteins from Mycoplasma hominis strains detected by SDS-PAGE, two-dimensional gel electrophoresis and immunoblotting.

The proteins of 14 strains of Mycoplasma hominis were compared by SDS-PAGE in gradient gels, by two-dimensional (2D) gel electrophoresis of extracts of 35S-labelled cells and by immunoblot analysis of cell proteins. The strains examined included the M. hominis type strain PG21 and 13 others isolated variously from genital tract, mouth, blood, upper urinary tract and a wound. These 14 strains shared 76-99% of proteins in SDS-gradient gel analysis and 41-72% in the 2D gels. As expected, the immunoblot analysis likewise revealed the existence of an extensive common protein pattern in M. hominis, in addition to a number of antigens shared only by some strains.

Antigens, Bacterial↗
PubMed1987

Genomic and gene variation in Mycoplasma hominis strains.

DNAs from 14 strains of Mycoplasma hominis isolated from various habitats, including strain PG21, were analyzed for genomic heterogeneity. DNA-DNA filter hybridization values were from 51 to 91%. Restriction endonuclease digestion patterns, analyzed by agarose gel electrophoresis, revealed no identity or cluster formation between strains. Variation within M. hominis rRNA genes was analyzed by Southern hybridization of EcoRI-cleaved DNA hybridized with a cloned fragment of the rRNA gene from the mycoplasma strain PG50. Five of the M. hominis strains showed identical hybridization patterns. These hybridization patterns were compared with those of 12 other mycoplasma species, which showed a much more complex band pattern. Cloned nonribosomal RNA gene fragments of M. hominis PG21 DNA were analyzed, and the fragments were used to demonstrate heterogeneity among the strains. A monoclonal antibody against strain PG21 was produced. The possible presence of the corresponding antigenic epitope in the other 13 M. hominis strains was analyzed by immunoblotting and compared with results of immunoblotting using polyclonal antibodies against PG21.

Antibodies, Bacterial↗
PubMed1986

Hospice.

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Hospices↗
PubMed1986

Efficacy of captopril and hydrochlorothiazide administered once a day.

One hundred and ten mild and moderately hypertensive patients were treated with a fixed combination of captopril 50 mg and hydrochlorothiazide 25 mg (Capozide 50) once daily for 12 months. Eighty four patients were treated initially with Capozide 50 12 hourly for 3 months before receiving Capozide 50 o.d.; the other 26 patients received Capozide 50 as initial treatment immediately after the placebo run-in period. Blood pressures were measured 24 hours after ingestion of the drug. Capozide 50 once daily induced statistically significant reductions in supine blood pressure and these beneficial effects were sustained throughout the duration of the trial. In patients receiving Capozide 50 as initial therapy, a gradual hypotensive effect was seen. No clinically significant changes in biochemical or haematological variables were recorded although a small but statistically significant rise in uric acid was noted. This latter effect was attributed to the thiazide component of the combination. The efficacy and safety profile of this once-a-day compound makes it an ideal therapeutic agent for the management of mild and moderate hypertension.

Blood Pressure↗
PubMed1984

A quantitative cytochemical assay of beta-galactosidase in single cultured human skin fibroblasts.

A quantitative cytochemical method for the measurement of beta-galactosidase activity in cultured human skin fibroblasts has been developed using 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside as the indigogenic substrate. The method relies upon the oxidation of the primary reaction product by ferro/ferricyanide during which an insoluble indigo dye is generated as the final reaction product. The reaction was linear with time up to 60 min using the final cytochemical standard procedure. The enzyme showed maximum activity at pH 4.0 to 4.1. The concentration optima of indigogenic substrate and potassium ferro/ferricyanide were 3.67 mM and 3.13 mM respectively. The presence of sodium chloride activated beta-galactosidase up to 100 mM, but was inhibitory above that concentration. The enzyme was inhibited by N-ethylmaleimide, N-acetyl-D-galactosamine and heparin. The enzyme molecules were shown to diffuse out of the cells using media without a suitable inert colloid stabilizer. However, diffusion was completely prevented by using polyvinyl alcohol (PVA) grade G18/140. Air-drying of cells was essential to make the cell membrane permeabel to the substrate and, thereby, to avoid a pronounced lag phase. However, in a biochemical analysis, air-drying itself caused a decrease in enzyme activity to 43% of the control. Even after air-drying lysosomal latency could still be demonstrated by using PVA grade G04/140. Control persons, one carrier of and two patients with beta-galactosidase deficiency were easily identified as belonging to three separate groups by using the cytochemical assay. It is proposed that the quantitative cytochemical approach may also be applied to cultured human amniotic fluid cells or chorion biopsies giving a rapid prenatal diagnosis of beta-galactosidase deficiency due to the small number of cells needed in the analysis.

Cells, Cultured↗
PubMed1984

Electrophoretic analysis of proteins from Mycoplasma capricolum and related serotypes using extracts from intact cells and from minicells containing cloned mycoplasma DNA.

The acidic proteins of six different mycoplasma serotypes causing bovine or caprine pleuropneumonia were compared by two-dimensional gel electrophoresis of extracts of 35S-labelled cells. The organisms investigated were Mycoplasma mycoides subsp. mycoides (PG1), M. mycoides subsp. mycoides (Y-goat), M. mycoides subsp. capri (PG3), M. capricolum (California kid), the unclassified bovine serogroup 7 of Leach (PG50) and the F38-like group (F38). The results suggested a close relationship between M. capricolum and F38 and a similarly close relationship between the different M. mycoides subspecies, whereas the two M. mycoides subspecies appeared to be quite distant from M. capricolum and F38. The representative strain of the bovine serogroup 7 of Leach was equally distant from F38, M. capricolum and the three strains of M. mycoides. Strikingly, all six mycoplasma strains apparently shared six proteins in the two-dimensional gels. In Escherichia coli minicells, DNA from strain PG50 cloned in the vector pBR325 gave rise to incorporation of radioactive label into proteins which were identified as mycoplasma proteins by two-dimensional electrophoresis and immunoprecipitation.

Autoradiography↗
PubMed1984

Analysis of the mycoplasma genome by recombinant DNA technology.

A library of DNA fragments from Mycoplasma sp. strain PG50 has been made in the vector pBR325. Analysis in Escherichia coli minicells of randomly picked clones from this library demonstrated that many plasmids can promote synthesis of mycoplasma protein in the E. coli genetic background. Screening with labeled rRNA identified plasmids with sequences from the beginning of the rRNA cistron to about two-thirds within the gene for 23S rRNA. Use of these plasmids as probes allowed an accurate determination of the number of RNA cistrons as two, and demonstrated that the cistrons are more than 20 kbp apart. The DNA sequence of 16S rRNA and the surrounding control regions has been determined.

Bacterial Proteins↗
PubMed1983

Succinate dehydrogenase activity in cultured human skin fibroblasts and amniotic fluid cells. A methodological study.

Through a methodological evaluation, reliable histochemical and biochemical methods for succinate dehydrogenase activity in cultured human skin fibroblasts and amniotic fluid cells were developed. The histochemical method includes a cleaning of the cultured cells in 1 mM malonate in 0.9% NaCl, air-drying and fixation in acetone (5 min at -20 degrees C), coating of cells with CoQ10 (0.2 mg/ml in ether/acetone) and incubation for 1 h at 37 degrees C in 50 mM succinate and 0.5 mg/ml Nitro BT in 200 mM phosphate buffer, pH 7.6 PMS as an intermediate electron carrier was found inferior to exogenous CoQ10. Both types of cells exhibit equal activity. In the biochemical method homogenizing was performed in 50 mM Tris-HCl buffer, pH 7.5, and 200 mM sucrose. The standard incubation was 2.0 mM INT and 10 mM succinate in 10 mM Tris-HCl buffer, pH 7.5 for 1 h at 37 degrees C. The apparent Km values for INT and succinate were estimated to 0.39 mM and 0.13 mM, respectively, while I0.5 for malonate was 0.46 mM. Activity in amniotic fluid cells was 18.1 pkat/mg protein and in human skin fibroblasts 20.3 pkat/mg protein. Specificity of the methods was tested by use of a Chinese hamster fibroblast strain B9 known to be succinate dehydrogenase deficient in addition to various control experiments. Congruent results were obtained with the two methods.

Amniotic Fluid↗
PubMed1980

Treatment of girls with excessive height prediction. Follow-up of forty girls treated with intramuscular estradiol and progesterone.

In a follow-up study of 40 tall girls treated with intramuscular estradiol and progesterone, the final height, bone age maturation, side effects and acceptance of treatment were evaluated. The mean duration of treatment was 18 months. During treatment, mean height increase was 6.5 cm (height velocity 3.7 cm/year), which is nearly 50% reduction of normal growth rate. The mean increase in bone age was 2.7 years (bone age velocity 1.8 years/year), which approximates twice the normal maturation rate. The mean reduction in final height was 5.0 cm as evaluated by the method of Bayley. Pinneau (BP), 2.9 cm by the method of Tanner et al. (TW) and 3.0 cm by the method of Roche et al. (RWT). The reduction was greatest when treatment was started before menarche, according to all three prediction methods. When treatment was started after menarch the calculated height reduction was greatest according to the BP method. There was good agreement between the three prediction methods in girls with a bone age below 12 years before treatment. In girls with a bone age above 12 years the height reduction by the BP method was much greater than when measured by the other methods. Side effects evaluated at follow-up were minimal and first menstruation occurred within 3 months (mean) after cessation of treatment. The number of pregnancies was estimated to be normal for age. All but three accepted the treatment. It is concluded that this type of treatment must be restricted to girls with severe psychological problems due to excessive height prognosis and selection for treatment must be based on an individualized evaluation.

Adolescent↗