Biomedical subjects

D Martens

Publications and source records attributed to D Martens.

31 records · Page 2Linked to original sources

PubMed1990

[Alcohol withdrawal syndrome in the postoperative phase--therapy or prevention?].

In a prospective study 50 patients who reported regular ethanol consumption and who underwent neck dissection were evaluated by clinical examination and the Munich alcohol test (MALT). 31 patients were not classified as alcohol abusers and none of them developed withdrawal symptoms (WS) postoperatively. 19 patients were diagnosed as alcohol abusers; 9 of them (group 1) received symptomatic therapy with clomethiazol and haloperidol, 10 patients (group 2) received continuous ethanol infusions (2-4 g/h) postoperatively as prophylaxis for WS. 6 patients in group 1 developed WS; none of group 2 developed WS. Thus the period of intensive care therapy of group 2 was significantly shorter (3.0 versus 11.5 days). It was concluded that postoperative continuous ethanol infusions prevent the occurrence of WS and should be administered to severely alcoholic patients.

Alcohol Withdrawal Delirium↗

PubMed1988

[3H]-8-cyclopentyl-1,3-dipropylxanthine binding to A1 adenosine receptors of intact rat ventricular myocytes.

The purpose of the present study was the identification of A1 adenosine receptors in intact rat ventricular myocytes, which are thought to mediate the negative inotropic effects of adenosine. The adenosine receptor antagonist [3H]-8-cyclopentyl-1,3-dipropylxanthine was used as radioligand. Binding of the radioligand to intact myocytes was rapid, reversible, and saturable with a binding capacity of 40,000 binding sites per cell. The dissociation constant of the radioligand was 0.48 nM. The adenosine receptor antagonists 8-cyclopentyl-1,3-dipropylxanthine, "xanthine amine congener," and theophylline were competitive inhibitors with affinities in agreement with results obtained for A1 receptors in other tissues. Competition experiments using the adenosine receptor agonists R-N(6)-phenylisopropyladenosine, 5'-N-ethylcarboxamidoadenosine, and S-N(6)-phenylisopropyladenosine gave monophasic displacement curves with Ki values of 50 nM, 440 nM, and 4,300 nM, which agreed well with the GTP-inducible low affinity state in cardiac membranes. The low affinity for agonists was not due to agonist-induced desensitization, and correlated well with the corresponding IC50 values for the inhibition of cyclic AMP accumulation by isoprenaline. It is suggested that only a low affinity state of A1 receptors can be detected in intact rat myocytes due to the presence of high concentrations of guanine nucleotides in intact cells.

Animals↗

PubMed1987

Pharmacological characterization of A1 adenosine receptors in isolated rat ventricular myocytes.

The aim of the present study was the characterization of adenosine receptors in isolated rat ventricular myocytes. The cAMP-levels of rat ventricular myocytes in the presence of 1 mumol/l isoprenaline were reduced by up to 48% by adenosine analogues; the rank order of potency was: R-N6-phenylisopropyladenosine (IC50 60 nmol/l), 5'-N-ethylcarboxamidoadenosine (IC50 360 nmol/l) and S-N6-phenylisopropyladenosine (IC50 16 mumol/l). The adenosine receptor antagonist XAC ("xanthine amine congener") antagonized the effect of R-N6-phenylisopropyladenosine in a concentration-dependent manner with a Ki-value of 20 nmol/l. The A1 receptor-selective radioligand R-N6-125I-p-hydroxyphenylisopropyladenosine bound to membranes prepared from rat ventricular myocytes in a saturable manner with a Bmax of 17.7 fmol/mg protein and a KD-value of 1.1 nmol/l. Adenosine analogues competed for the binding with the same rank order of potency as for the inhibition of the isoprenaline-induced cAMP-increase. GTP inhibited radioligand binding with an IC50-value of 73 mumol/l. These results suggest the presence of A1 adenosine receptors on rat ventricular myocytes, which mediate an inhibition of adenylate cyclase. The receptors may be responsible for the effects of adenosine and its analogues on the heart.

Adenosine↗

PubMed1987

Management of simple depressed skull fractures in children.

Surgical elevation is the treatment usually recommended for a simple depressed skull fracture if the depression is more than the full thickness of the adjacent skull, but there is no clinical evidence to support this management. On that basis, a progressively more conservative approach to the treatment of this condition was adopted, especially in young children. Experience with this mode of management over the period 1972 to 1984 is presented. Of 111 patients under 16 years of age with depressed skull fractures, 64 had simple and 47 compound fractures. Simple depressed skull fractures occurred in a younger age group after less significant trauma than compound fractures. In those patients who were treated surgically, there was an 11% incidence of dural laceration in patients with simple depressed fractures versus 67% for the patients with compound depressed fractures. There was no difference in outcome between surgically and nonsurgically treated patients with simple depressed fractures with respect to the occurrence of seizures, neurological dysfunction, or cosmetic appearance. Surgical treatment prolonged hospitalization, and the only case with a fatal outcome was found in the group of patients treated surgically. It is suggested that the standard treatment of simple depressed skull fractures in the pediatric age group should not include surgery. Surgery is indicated when there is definite evidence of dural penetration and in the older child with an unacceptable cosmetic appearance.

Child↗

PubMed1987

Syringes versus minibags as an intravenous admixture system: a comparison of cost and nursing preference.

The implementation of centralized intravenous admixture programs in Canadian hospitals has been hindered by the high costs associated with such programs. The most popular system uses minibags as an admixture base but other less expensive alternatives are being investigated. This study examines the material and labour costs associated with preparing admixtures in either minibags or polypropylene syringes. The minibag admixtures were administered by nursing staff using secondary medication administration sets. Standard volume-control sets were used for diluting and administering the intravenous admixtures supplied in syringes. The results indicated a major cost advantage for the syringe-based program. Furthermore, evaluation of the two systems by nursing staff indicated a strong preference for the syringe-based system.

Attitude of Health Personnel↗

PubMed1980