| 1. |
- Karlsson, Jan-Erik, et al.
(författare)
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Ambulatory ST-recording has no additional value to exercise test for identification of severe coronary lesions after an episode of unstable coronary artery disease in men
- 1993
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Ingår i: International Journal of Cardiac Imaging. - : Wolters Kluwer. - 0167-9899. ; 9:4, s. 281-289
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Tidskriftsartikel (refereegranskat)abstract
- One month after an episode of unstable coronary artery disease, 95 male patients performed coronary angiography, 48 hours ambulatory ST-recording and also an exercise test. ST-depression occurred in 29.5% during the ST-recording and in 44.2% during the exercise test (p<0.05). In patients with ST-depression at ambulatory monitoring, 79% demonstrated the same finding at the exercise test. A high risk response at the exercise test - defined as either ST-depression in ≥ 3 leads, ST-depression in 1-2 leads with a maximal work load below the 60th percentile or a maximal work load below the 30th percentile regardless of the ECG reaction - occurred in 56.8%. Severe coronary lesions - defined as three vessel disease, left main stenosis or proximal left anterior descending artery stenosis as part of two vessel disease - was observed in 46.3%. Patents with a high risk exercise test response and patients with ST-depression during ST-recording had severe coronary lesions in 67% and 64% respectively. However, a high risk exercise test response occurred in 82%, while ST-depression at ambulatory monitoring was observed only in 41% of the patients with severe coronary lesions (p < 0.001). Thus, ambulatory ST-recording one month after an episode of unstable coronary artery disease in men adds no further information to a symptom limited exercise test in order to identify patients with severe coronary lesions.
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| 2. |
- Carlsson, Björn, 1958, et al.
(författare)
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Expression and physiological significance of growth hormone receptors and growth hormone binding proteins in rat and man.
- 1991
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Ingår i: Acta paediatrica Scandinavica. Supplement. - 0300-8843. ; 379
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Tidskriftsartikel (refereegranskat)abstract
- The molecular structure of the GH receptor has recently been characterized and the receptor identified as a member of a new receptor superfamily that includes the prolactin receptor and several cytokine receptors. No obvious signal transducing domain has been identified on any of these related receptors. One possible signalling mechanism involves receptor interaction with other membrane-associated proteins that function as mediators of signal transduction. Whether such a mechanism is involved in signal transduction of the GH receptor is not known. Another common feature of these receptors is the presence of soluble forms such as the GHBP. The functions of these proteins in the circulation and at the level of the target cell remain to be resolved.
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| 3. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Embryonic stem cells express growth hormone receptors: regulation by retinoic acid.
- 1993
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Ingår i: Endocrinology. - 0013-7227. ; 133:6, s. 2897-903
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Tidskriftsartikel (refereegranskat)abstract
- Embryonic and fetal growth are generally considered to be independent of pituitary GH. However, it has been demonstrated recently that 18-day-old rat embryos and rat fetuses express GH receptors, suggesting that GH could play a role in early development. The aim of the present investigation was to determine whether preimplantation embryos also express GH receptors. Germ line competent mouse embryonic stem (ES) cells and cultured mouse preimplantation embryos were examined with Northern blot analysis, RNAse-protection solution-hybridization assays, reverse transcription/polymerase chain reaction assays and immunohistochemistry for the detection of GH receptors. Northern blot analysis of ES cells using a probe corresponding to the extracellular domain of the GH receptor demonstrated the presence of two transcripts (1.2 and 4.5 kilobases). The RNAse-protection solution-hybridization assay revealed that ES cells express approximately one sixth of the GH-receptor messenger RNA (mRNA) levels expressed in liver from pregnant mice. Treatment of cultured ES cells with retinoic acid (100 nM) for 6 days increased GH-receptor mRNA levels (P < 0.01). GH-receptor mRNA was further identified in ES cells, preimplantation embryos, muscle, liver, and placenta by a reverse transcription/polymerase chain reaction assay. In humans it has previously been shown that exon 3 of the GH-receptor is deleted in the placenta. However, none of the studied mouse tissues had a deletion of the GH-receptor mRNA corresponding to exon 3 of the human GH receptor. GH-receptor immunoreactivity was identified on the cultured ES-cells by immunohistochemistry. In conclusion, we have in the present study shown that germline competent ES cells and preimplantation mouse embryos express the GH receptor transcript and that this transcription is increased by retinoic acid in ES cells. Furthermore, the presence of GH-receptor immunoreactivity on the ES cells indicates that the GH-receptor transcript is translated.
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| 4. |
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| 5. |
- Paul, Jan, et al.
(författare)
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Temperature dependence of CO ligation to LegHb and Mb: 0-80°C
- 1994
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 231:4-6, s. 547-550
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Tidskriftsartikel (refereegranskat)abstract
- The temperature dependence of the coordination of CO to two hemoproteins, myoglobin (Mb) and leghemoglobin (LegHb), has been studied by absorption spectroscopy. All spectral changes in the electronic and infrared ranges are fully reversible between 8 and 88°C and indicate a more linear orientation of the distal ligand with increasing temperature. The characteristic energy for the above spectral changes is around 200 cm-1 or identical to the Fe-Imidazole (Im) mode in hemoproteins. Our results are also compared with recent models for the dynamics of CO adsorbed at the surfaces of transition metals. Based on these surface models we suggest that our observed temperature dependences stem from thermal excitations of the Fe-Im vibration. This implies a so far undocumented mechanism by which the Fe-proximal bond influences the binding and energy dissipation at the active site of hemoproteins.
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| 6. |
- Sandstedt, J, et al.
(författare)
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Disproportional bone growth and reduced weight gain in gonadectomized male bovine growth hormone transgenic and normal mice.
- 1994
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Ingår i: Endocrinology. - 0013-7227. ; 135:6, s. 2574-80
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Tidskriftsartikel (refereegranskat)abstract
- Sex steroids have been shown to influence longitudinal bone growth during sexual maturation, partially by increased GH secretion. Mice transgenic for metallothionein promoter bovine GH were developed by pronuclear injection as a model with sex steroid-independent GH secretion. Prepubertal normal and transgenic, male and female mice were either gonadectomized or sham operated. The growth was divided into two segments: peripubertal growth from 30-60 days of age and adult growth from 60-90 days of age. Orchidectomy resulted in a decreased growth rate of the lumbar spine and a decreased weight gain during the peripubertal growth, whereas tibia growth was unaffected. The alteration in proportions between the lumbar spine and the tibia was apparent for both normal and bovine GH transgenic mice, suggesting that the effect was not mediated via decreased GH secretion. Orchidectomy resulted in increased adult tibial growth, whereas weight gain and lumbar growth were unaffected. In female mice, gonadectomy did not influence these parameters during either time period studied. In summary, we present data indicating that the male gonads in a GH secretion-independent manner stimulate pubertal growth of the spine and inhibit the tibial growth of adult animals.
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| 7. |
- Smith, M.L., et al.
(författare)
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Heme-protein fission under non-denaturing conditions
- 1991
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 88:3, s. 882-886
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Tidskriftsartikel (refereegranskat)abstract
- Slow heme transfer from horseradish peroxidases C2 and A2, cytochrome c peroxidase, chloroperoxidase, and leghemoglobins to a heme acceptor protein, apomyoglobin, has been studied under mild conditions. The reaction is best described as heme release into water followed by quick engulfment by apomyoglobin. The energetics of the activated process are large and interpreted as connected to both polypeptide motions during release and the ordering of water around the heme during solvation. The free energy required to break the iron(III)-ligand 5 (L5) bond is a minor but crucial portion of the activation free energy. Donor-acceptor protein interactions are not involved in the transfer. Fast heme release from inactive protein has also been observed. Apoprotein recombination with porphyrins and hemes suggest that this lack of activity is a result of Fe-L5 bond breaking.
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