In vivo studies have shown that high blood concentrations of pituitary-adrenocortical hormones can activate the hippocampal cholinergic terminals. Incubation of hippocampal synaptosomal preparations ...with methylprednisolone, or with ACTH at concentrations comparable to stress-induced high concentrations in plasma, did not have any significant effects on the cholinergic parameters measured under unactivated conditions. In the presence of either high K+ or of ACh, choline uptake was decreased. This decrease was not affected by methylprednisolone. However, methylprednisolone did enhance ACh release both after a previous increase (induced by K+) or a decrease (induced by ACh) of ACh release. In contrast, ACTH had no direct effects on either unactivated or K+-stimulated synaptosomes. Thus, a differential effect was exerted by methylprednisolone on the two presynaptic regulatory mechanisms: choline uptake (no change) and ACh release (increase). We suggest that the activation, observed in vivo, resulted mainly from indirect action of the hormones on the hippocampal cholinergic terminals, in view of the fact that the direct effect in vitro was partial.
Isosorbide‐5‐mononitrate (ISMN), the main metabolite of isosorbide dinitrate (ISDN) was recently introduced in clinical use. The hemodynamic effects of oral ISMN and ISDN, administered in equal ...doses, were studied in a randomized, crossover fashion in 20 patients with pump failure of ischemic etiology. Baseline hemodynamic criteria for admission into the study were: pulmonary capillary wedge pressure (PCW) of at least 20 mmHg and systolic arterial pressure (AP) above 90 mmHg. Hemodynamic parameters were serially measured and systemic vascular resistance was calculated up to 6 h postadministration of either ISMN or ISDN single dose (40 mg). Maximal effects obtained were statistically significantly different from baseline. While ISMN and ISDN appeared to be equipotent in reducing the filling pressure, with a maximum effect reached in 60–120 min, the mononitrate maintained its effects for a longer period.
A specific subset of acute myocardial infarction was defined and named 'the hypertensive-hyperkinetic-coronary-active' subgroup. This subgroup included patients with acute myocardial infarction ...without pump failure or hypovolemia who continued to have hypertension and tachycardia, after relief of pain and who also had at least two recurrent ischemic episodes in the first days after a transmural event. Fifteen patients belonging to this group (group A) were studied in comparison with 15 other patients with acute myocardial infarction complicated by pump failure (group B). The alterations in hemodynamics, in circulating catecholamine levels and the clinical course during an intravenous infusion of isosorbide dinitrate were evaluated and the data obtained in the two groups were compared. The patients in group A had tachycardia, hypertension and upper normal filling pressures (pulmonary capillary wedge pressures: 15.8 +/- 1.8 mm Hg). They had high levels of circulating catecholamines (1,343 +/- 407 ng/l), a cardiac output of 5.9 +/- 0.6 liters/min and stroke work index of 78 +/- 11 (mean +/- SD). The effect of intravenous nitrates on the left ventricular function curves of the two groups was the following: a marked shift downward and slight shift to the left in group A, as opposed to a moderate but significant shift upward and marked shift to the left in group B. The episodes of recurrent ischemia subsided in 13 out of 15 patients from group A. It appears therefore that the hyperkinetic patients with acute infarction are characterized by a hypersympathetic response, a typical hemodynamic profile and a particular response to nitrate therapy directionally opposite to the changes obtained in patients with acute infarction complicated with failure.
Sheep lungs experimentally and naturally affected by bronchoalveolar carcinoma were washed out exhaustively of soluble components by phosphate-buffered saline, pH 7.4 (PBS), followed by glycine ...buffer, pH 2.8 (GB), and then again by 1M KCl followed by PBS. The tissue matrix (TM) of the tumor-free region and the tumor-affected tissue were analysed separately by sodium dodecyl sulfate (SDS) polyacrylamide electrophoresis. Normal lung tissues obtained from normal sheep served as controls. Several protein fractions and fragments, identified in both the normal and the tumorous lung, have the molecular weight (MW) of 130,000-228,000, as compared with the major soluble tissue associated protein having MW of 70,000. Coomassie blue staining used in the SDS polyacrylamide system and alkaline phosphatase immunoreaction used in the Enzyme Linked Immunosorbant Assay (ELISA) showed tenfold increased concentration of the TAPC in the TM of the tumor tissue and in the blood of tumor-affected animals, respectively. Total concentration of the TAPC in the serum of tumor-affected animals was higher than in the normal. Immunofluorescent antibody test (IAT) detected the TAPC in the cytoplasm of tumor as well as in normal lung cells, and the study suggested that the TAPC reaches the peripheral blood during tissue destruction occurring at the tumor site, as observed by light and electron microscopy (LM and EM). The concentration of each of the TAPC fractions was higher in the tumor-affected sheep lung as compared with normal sheep lung. Antibodies prepared against the TAPC fractions were toxic to sheep lung cells in tissue culture. Tumor cells were more susceptible.
Since thrombi continue to incorporate fibrin during lysis we tested the effect of pretreatment with ancrod, a defibrinating agent from Malaysian pit viper venom, on thrombolysis with urokinase and ...streptokinase. Thrombi were induced by copper-coils in the carotid arteries of the dogs, weighed after 1 hour and inserted into the femoral arteries of the same animals. They were then exposed for 15 min to iv boluses of streptokinase 10,000 U/kg, urokinase 10,000 U/kg and urokinase 25,000 U/kg with or without pretreatment with ancrod. Ancrod depleted fibrinogen within 5 min and enhanced the lytic effect of streptokinase from 25 +/- 8% to 59 +/- 13% (p less than .05), urokinase 10,000 U/kg from 16 +/- 11% to 66 +/- 18% (p less than .01) and urokinase 25,000 U/kg from 27 +/- 17% to 85 +/- 8% (p less than .001) of the initial thrombus weight. Ancrod itself did not activate plasminogen to plasmin. We conclude that ancrod enhances thrombolysis probably by depleting fibrinogen and preventing new fibrin incorporation into the thrombus during lysis.
We demonstrate a high-order frequency filter based on microring pairs, capable of restoring distorted transmission functions by dynamically adjusting resonance parameters. Individual rings are ...thermo-optically tunable and are adjusted based on an evolutionary algorithm.
Pindolol-induced tremor Hod, H.; Har-Zahav, J.; Kaplinsky, N. ...
Postgraduate medical journal,
05/1980, Letnik:
56, Številka:
655
Journal Article
Recenzirano
Odprti dostop
Five patients were treated with pindolol for various indications. The patients called attention to the appearance of fine tremors in their extremities 6-72 hr after starting treatment with the drug. ...The tremors disappeared 24-72 hr after stopping the drug. Beta-adrenoceptor-blockers are known to suppress different types of tremor and the paradoxical appearance of tremors during pindolol treatment is attributed to its powerful partial agonist activity. To the best of the authors' knowledge this side effect has not been previously described in the literature.
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