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Biomedical subjects

O Thulesius

Publications and source records attributed to O Thulesius.

At least 109 records · Page 6Linked to original sources
PubMed1983

Vascular effects of glucocorticosteroids, with special reference to budesonide.

The effect of glucocorticosteroids was tested on in vitro responses of tension developed by strips of umbilical blood vessels. 1. Hydrocortisone, methylprednisolone and dexametasone in concentrations of 10(-4)-10(-3) mainly inhibited spontaneous tone. Hydrocortisone and methylprednisolone induced a biphasic response with an initial small contraction followed by a more long lasting relaxation. 2. Budesonide, a novel powerful, non-halogenated steroid only induced a long lasting contraction. 3. The relaxation with hydrocortisone was of the same magnitude as after indomethacine, therefore, this response may be due to inhibition of prostaglandin-synthesis. 4. There was no leftward shift of the dose response curve to catecholamine stimulation but rather a slightly higher maximal response. There is no clear evidence of a uptake-2 blockade in our preparation.

Budesonide↗
PubMed1983

Vascular responses elicited by venom of Arabian catfish (Arius thallasinus).

The Arabian catfish produces venoms from the skin (SV) and glands near the pectoral spines (GV). 1. The venoms have a high protein concentration, only limited amounts of lipid, carbohydrate and nucleic acid. Enzyme activities included alkaline phosphatase and esterases. Both SV and GV induce hemolysis. 2. SV and GV induced a dose-dependent smooth muscle contraction of human umbilical artery preparations. This response was competitively inhibited by atropine, suggesting a cholinergic response. 3. Heat treatment of GV did not decrease activity, while heating SV reduced it. 4. In-vivo experiments showed mainly a depressor response in rat and guinea-pig.

Animals↗
PubMed1982

Vasodilating properties of beta-adrenoceptor blockers with intrinsic sympathomimetic activity.

1 In vitro experiments have been performed using 33 preparations of human arteries and veins and 10 human umbilical artery preparations. Changes in the tone of helical strips of vasculature were recorded isometrically following contraction of the tissues by exposure to 5-hydroxytryptamine (10(-6)--10(-5) M) or potassium (127 mM). 2 Isoprenaline included concentration-dependent relaxation and this effect could be competitively antagonized by propranolol or sotalol. 3 The beta-adrenoceptor antagonists pindolol and celiprolol, both of which possess intrinsic sympathomimetic activity, produced concentration-dependent relaxations of arteries and veins but not of umbilical vessels. 4 The relaxation produced by pindolol or celiprolol could be antagonized but not abolished by pretreatment with propranolol or sotalol. 5 It is concluded that the vascular relaxation produced by beta-adrenoceptor antagonists with intrinsic sympathomimetic activity is the result of beta 2-adrenoceptor stimulation. In the case of pindolol the relaxant effects were seen at concentrations within the range encountered after administration of normal therapeutic doses suggesting that this effect may contribute to the haemodynamic responses to pindolol seen in man.

Adrenergic beta-Antagonists↗
PubMed1982

Non-invasive investigation of vascular compression in patients with thoracic outlet syndrome.

Three hundred and seventy-seven patients with brachial pain and 63 controls have been examined regarding presence of symptomatic compression of the brachial plexus and subclavian vessels (Thoracic Outlet Syndrome = TOS). Each patient was examined clinically and by Doppler flowmetry. Two hundred and thirty (61%) had moderate to pronounced compression of the brachial plexus and 11 (2.9%) isolated compression of the subclavian artery or vein. One hundred and twenty-nine patients had symptoms not related to TOS. The prevalence of TOS was almost twice as common in women as in men, 1.76:1. The TOS patients were younger than the non-TOS patients, P less than 0.05. There was a significant correlation between arterial compression measured by Doppler flowmetry and the presence of compression of the plexus, P less than 0.001. But the validity of this method was not satisfactory, giving both false positive and negative results. Furthermore, there was a very good correlation between arterial compression assessed clinically and by Doppler flowmetry, P less than 0.001. Thus, the diagnosis of TOS is still a clinical judgement, the Doppler technique adding very little and any significant vascular compression being easily detected by clinical assessment.

Adolescent↗
PubMed1982

Response of finger systolic blood pressure to cold provocation in cases with hypertension and diabetes.

Finger systolic blood pressure during cooling was determined in 21 hypertensive, 22 diabetics and 18 control individuals. Blood pressure determination was made using a miniature tourniquet on the middle phalanx and a strain-gauge flow sensor on the finger tip. Pressure was measured at 35 degrees C and upon stepwise local cooling down to 5 degrees C. With this technique the following observations were made: (1) Systolic blood pressure declined slightly in controls. (2) The reduction of finger systolic blood pressure was significantly more pronounced in patients with essential hypertension and diabetes, 17 and 23% at 5 degrees C compared to control level at 35 degrees C. (3) These changes may be explained simply on the basis of physical factors such as altered wall composition resulting in decreased and retarded compliance.

Adolescent↗
PubMed1982

Adrenergic and cholinergic induced contractions of tracheal smooth muscle in the rabbit as demonstrated by a new in vivo method.

An in vivo tracheal muscle preparation in the rabbit was developed which enabled us to measure changes in the isometric tension of the trachealis muscle in response to electrical stimulation of autonomic nerves and to i.v. administration of autonomic agonists and antagonists. The preparation was very sensitive to injections of carbachol, and showed graded contractions to stimulation of the caudal end of the cut cervical vagus as frequency and strength of stimulation were increased. Stimulation of the rostral end of the cut cervical sympathetic nerve fibers produced contractions in all preparations. This effect was mimicked by the alpha-adrenoceptor agonist, phenylephrine. The effects of both sympathetic stimulation and phenylephrine were blocked by phentolamine and not inhibited by pretreatment with atropine or propranolol. Sympathetic stimulation produced contractions of the trachealis muscle whether the initial tone was normal or actively increased by carbachol, while adrenaline produced relaxation when the initial tone was high. Using this new in vivo trachealis muscle preparation in the rabbit, we could show that sympathetic stimulation produced contractions of the trachealis muscle. This effect is consistent with the existence of smooth muscle activating alpha adrenoceptors.

Adrenergic Fibers↗
PubMed1981

Response of digital blood pressure to cold provocation in cases with Raynaud phenomena.

A new diagnostic test of the qualitative and quantitative evaluation of vasospastic disorders is described. It entails measurement of systolic digital artery pressure during successive cooling from 35-5 degrees C. In cases with vasospastic disorders with Raynaud phenomena a significant reduction of systolic blood pressure below 78% of control level is observed and in the most pronounced cases total cessation of flow occurs (critical closing). The test is also a quantitative measure of the degree of vasospasm since the pressure reduction correlates to the clinical degree of vasoconstriction.

Adolescent↗