| 1. |
- Andersson-Engels, S., et al.
(författare)
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Tissue diagnostics using laser-induced fluorescence
- 1989
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Ingår i: Berichte der Bunsengesellschaft für Physikalische Chemie. - : Wiley. - 0005-9021. ; 93:3, s. 335-342
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Tidskriftsartikel (refereegranskat)abstract
- We have performed extensive investigations of laser-induced fluorescence in animal and human tissue aimed at instant tissue characterization. Autofluorescence, as well as specific fluorescence from HPD/DHE and other photosensitizers, has been utilized. The studies have been focused on the demarcation of malignant tumours and atheroscleortic plaques. A nitrogen laser or an excimer-pumped dye laser was used to induce fluorescence, which was analysed with an intensified optical multichannel system. A fibre-optic sensor system was developed for the clinical work. Multi-colour fluorescence imaging has also been demonstrated along a line and equipment for two-dimensional imaging is being constructed. Dimensionless spectroscopic functions, which are not affected by factors that are clinically uncontrollable have been employed for optimum tissue discrimination. The investigations have so far been performed in a time-integrated mode, but time-resolved studies are now being initiated to fully exploit the diagnostic power of tissue laser-induced fluorescence. In addition to a presentation of our own work a brief review of tissue fluorescence studies performed by other groups is also given.
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| 2. |
- Janson, A M, et al.
(författare)
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Protective effects of chronic nicotine treatment on lesioned nigrostriatal dopamine neurons in the male rat
- 1989
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Ingår i: Progress in Brain Research. - 1875-7855. ; 79, s. 257-265
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Tidskriftsartikel (refereegranskat)abstract
- The present results demonstrate that chronic nicotine treatment can in part protect against mechanically-induced and neurotoxin-induced degeneration of nigrostriatal DA neurons. These results indicate that in sufficient doses chronic treatment with nicotine may be considered in the pharmacological treatment of Parkinson's disease. It remains to be demonstrated whether these protective actions can be extended to include also other injured neurons such as the cholinergic neurons, known to be severely affected in Alzheimer's disease.
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| 3. |
- Andersson, P. S., et al.
(författare)
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TISSUE CHARACTERIZATION USING LASER-INDUCED FLUORESCENCE.
- 1987
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Ingår i: Conference on Lasers and Electro-Optics. - 0936659491 ; 14, s. 46-48
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Konferensbidrag (refereegranskat)abstract
- In cancer tumor detection, tissue autofluorescence and characteristic features of injected hematoporphyrin derivative (HPD) can be utilized. The authors have studied the importance of the excitation wavelength for the achievable contrast between tumor and surrounding tissue using a rat tumor model. They have also compared the relative merits of two HPD preparations for tumor fluorescence detection. The real-time capability of the fluorescence technique is discussed.
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| 4. |
- Ingemarsson, Ingemar, et al.
(författare)
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Effects of isradipine, a new calcium antagonist, on postpartum uterine activity
- 1989
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349. ; 68:8, s. 725-730
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Tidskriftsartikel (refereegranskat)abstract
- The effects of a new calcium antagonist, isradipine (PN 200-110) on postpartum uterine activity and the maternal cardiovascular system were investigated. Uterine activity was recorded by a microtip transducer catheter inserted transcervically within 45 min of normal vaginal delivery. 0.5 mg of isradipine was given as a bolus injection during 5 min to 7 women with spontaneous uterine activity and 1 mg was given during a 15-min period to another 8 women with oxytocin-stimulated uterine activity. Matched controls with similar pre-injection activity (+/- 5%) but not given the drug were selected for comparison. The effects of the drug in 3 women (given 1 mg of isradipine) were compared with those in matched controls and in women given 0.25 mg of terbutalin i.v. as a bolus injection. Isradipine had a marked inhibitory effect on both spontaneous and oxytocin-stimulated uterine activity. The inhibitory effect of 1 mg of isradipine seemed comparable to that of 0.25 mg of terbutalin. The inhibition occurred within 1-2 min after the injection and was sustained throughout the study period (2 h). A transient reduction of the systolic (mean maximum decrease 10-15%) and diastolic blood pressure (mean maximum decrease 15-20%) was seen, particularly during the injection period. Hypotension (systolic blood pressure less than 80 mmHg) was not recorded. A moderate increase in pulse rate (mean maximum increase 22-27%) was seen in all cases. The results show that isradipine given as a bolus injection can inhibit early postpartum uterine activity, with minimal side effects.
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| 5. |
- Roepstorff, P., et al.
(författare)
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Application of Plasma Desorption Mass Spectrometry to Molecular Weight Determination of Structural Protein from Insect Cuticle
- 1986
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Ingår i: Journal of Mass Spectrometry. - : Wiley. - 1076-5174 .- 1096-9888. ; 13:12, s. 689-691
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Tidskriftsartikel (refereegranskat)abstract
- During sequence determination of a structural protein from the cuticle of the migratory locust, Locusta migratoria, a discrepancy was found between the molecular weight calculated from the sequence data (15 323) and that estimated by SDS-gel electrophoresis (21 600). The protein contains several repeated sequences, and the discrepancy might indicate that part of the sequence was missing or that the protein contained a large prosthetic group. The molecular weight of the protein was determined by 127I-plasma desorption mass spectrometry to be 15 329±50 which confirms the sequence data and shows the molecular weight determination based on SDS-electrophoresis to be too high.
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| 6. |
- Sjöberg, Trygve, et al.
(författare)
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Antagonism of thromboxane receptor induced contractions in isolated human groin lymphatics
- 1989
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Ingår i: Lymphology. - 0024-7766. ; 22:3, s. 135-140
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Tidskriftsartikel (refereegranskat)abstract
- In vitro studies were performed on lymphatics obtained from the groin in 19 patients undergoing vascular surgery. The lymphatics were mounted in tissue baths, and isometric contractions were induced by increasing concentrations of the thromboxane A2 (TXA2) mimetic U-46619. In comparison to K+ (124mM)-induced contraction, which were used as an internal standard, the response to U-46619 had an Emax of 105 +/- 5.9%. The pEC50-value was 8.14 +/- 0.09. The effects of two thromboxane receptor (TP-receptor) antagonists, L-636,499 and BM-13,505, were investigated. Both antagonists caused concentration-dependent right-ward shifts without depression of Emax of the U-46619 concentration-response curves. The slopes of the regression lines in a Schild plot for both antagonists did not differ from one, indicating competitive antagonism. The pA2-value of BM-13,505 (7.89) was 65 times higher than that of L-636,499 (6.08). The results suggest that the receptor involved in the prostanoid contraction in human groin lymphatics is of the TP-subtype.
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| 7. |
- Sjöberg, Trygve, et al.
(författare)
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Comparative effects of the alpha-adrenoceptor agonists noradrenaline, phenylephrine and clonidine in the human saphenous vein in vivo and in vitro
- 1989
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 136:3, s. 463-471
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Tidskriftsartikel (refereegranskat)abstract
- The alpha-adrenoceptor-mediated contractile effects of noradrenaline (alpha 1 + alpha 2), phenylephrine (alpha 1) and clonidine (alpha 2) on human saphenous veins were investigated in vivo and in vitro. By infusion (0.3 ml min-1) of the drugs (increasing concentrations in the infused solution) into distended (40 mmHg) saphenous veins in six healthy subjects, local vasoconstriction was induced, measured by a photo-electric device. The drugs induced dose-dependent contractions in all subjects, and dose-response curves were constructed. These were compared with concentration-response curves based on in-vitro results. Macroscopically normal saphenous veins, taken at saphenousectomies, were used, and the preparations were contracted isometrically in organ baths by the agonists. From the curves obtained in vivo and in vitro, the relative potencies of phenylephrine and clonidine (in relation to noradrenaline) were calculated and compared. The relative potencies of phenylephrine in vivo (76%) and in vitro (82%) did not differ significantly. However, the relative potency of clonidine was significantly (P less than 0.05) lower in vivo (90%) than in vitro (99%). Thus, it is concluded that there are differences between the results obtained in vivo and in vitro, stressing the importance of comparative in vivo-in vitro studies.
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| 8. |
- Sjöberg, Trygve, et al.
(författare)
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Contractile response in isolated human groin lymphatics
- 1987
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Ingår i: Lymphology. - 0024-7766. ; 20:3, s. 152-160
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Tidskriftsartikel (refereegranskat)abstract
- Lymphatics from the human superficial groin removed at operation in 21 patients (one with lymphedema) were examined in vitro. Histochemically no nerves were identified with either specific catecholamine fluorescence or immunoreactivity to tyrosine hydroxylase or dopamine beta-hydroxylase. Ring preparations of the lymphatics were mounted in tissue baths and isometric induced contractions were recorded after administration of K+ (124 mM), acetylcholine, selected amines and prostanoids. Noradrenaline (NA), adrenaline, dopamine, and acetylcholine had no or only weak contractile effects. In some segments, serotonin induced contractions. Prostaglandin E2 showed no contractile effect and prostaglandin F2 alpha induced contraction in most of the tested lymphatics. The prostaglandin-endoperoxide analogue U44069 uniformly elicited marked concentration-dependent contraction. In the lymphatic segment from the patient with lymphedema, a slightly greater contractile response to NA and serotonin was observed. The results overall suggest an absence of sympathetic innervation and contraction-mediating alpha adrenergic receptors in human superficial groin lymphatics, and support that certain prostanoids may be important regulators of human lymphatic contractility.
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