Antiplatelet effect of acetylsalicylic acid, metamizole and their combination - in vitro and in vivo comparisons.

BACKGROUND: Acetylsalicylic acid (ASA) plays an important role in the treatment and prevention of cardiovascular diseases. Metamizole (MET) is an analgesic and antipyretic medicine, it is not used as an antiplatelet drug. OBJECTIVES: We aimed to examine the antiplatelet effect of MET and the possible interactions between the drugs. METHODS: In our in vitro investigations different concentrations of ASA and MET solutions were added to blood. To examine the interactions MET and ASA were added together. In our in vivo crossover study intravenous MET, oral ASA or both drugs together were administered. Epinephrine and adenosine-diphosphate induced platelet aggregation was determined by optical aggregometry. RESULTS: Epinephrine-induced aggregation was completely inhibited in all ASA and MET concentrations in vitro. Lower, ineffective concentration of MET prevented the antiplatelet effect of ASA. The inhibition was completely restored when higher concentration of ASA was used or when ASA was added first. Our in vivo study showed that in the MET group rapid onset of inhibition was developed and there was no inhibition after one day. In the ASA group platelet aggregation decreased slowly but still had significant inhibitory effect after 72 hours. Combined therapy showed similar changes to the MET group. CONCLUSION: Antiplatelet effect of MET and ASA did not differ significantly in vitro. The observations may indicate a competitive interaction between the two drugs. The in vivo experiments showed that intravenously administered MET is an effective antiplatelet drug and can be considered as a therapeutic alternative, when ASA cannot be used in oral form.

Effects of repeated surgical stress on daily changes of body core temperature in mice.

Daily body core temperature rhythm has been known to become blunted for several days following intra-abdominal implantation of biotelemetry transmitters in small rodents and about a week is required for re-establishment of stable body core temperature oscillation. In the present study carried out on mice it was found that a repetition of the same minor surgical intervention (laparotomy) several days apart could speed up the stabilization of body temperature oscillations. Melatonin supplied with the drinking water continuously was found to speed up the return of stable daily body temperature rhythm further on consecutive laparotomies, while daily injections of methylprednisolone resulted in some delay in the development of stable body core temperature oscillations. It is concluded that in C57BL/6 mice possessing low plasma levels of melatonin exhibit an adaptive response to repeated stresses influencing the dynamics of daily body temperature rhythm.

Changes in plasma characteristics caused by easily ionisable elements in hollow cathode discharge emission spectrography.

The effect of several concomitant easily ionisable elements (EIE's), Li, Na, K, Rb and Cs on the line intensity of Sr II (first ionised state) and Al I and He I (atomic states) has been studied by atomic emission spectrometry (AES) hollow cathode (HCD) analysis. The spectral line intensities emitted by Sr II, Al I and He I have been measured while varying the volume of the EIE's concentrations, ranging from 0.1 mg ml to 10 mg ml. In the presence of EIE's at higher concentrations than 0.5% a considerable decrease of the line intensities of Sr II at 430.54 nm and 407.71 nm was observed, together with a gradual decrease in the line intensities of both Al I 494.40 nm and 396.15 nm, and He I 412.1 nm. It is demonstrated in the present experiments with a water-cooled HCD source that interference effects caused by EIE's are observed when the ratio of the number of gas atoms (n(g)) and atoms with low ionisation energy (n(a))n(g)/n(a)is lower than 10(12).

[Isoflurane. (Comparison with halothane and fentanyl anesthesia)]. / Az izofluránról. (Halotán és fentanyl anesztéziával való összehasonlításban).

Authors carried out during one and a half year 135 anaesthesias with isoflurane. 104 of them was administered in closed, and 31 in semi-closed system. The results were compared with halothane and fentanyl anaesthesias. After brief review of the literature about isoflurane, authors evaluated their own experiences The most favourable result was the stability of the metabolic acid-base balance. One explanation of this feature is the undisturbed oxygenation of the tissues. The circulation was characterized by mild tachycardia and by transitory decrease of the systolic blood pressure. The circulatory parameters were better in closed system, than in semi-closed one, and within the former system the most stable circulation was achieved either by an empirical syringe-injection administration, or by vaporizer administration using 5 -3,8 -3,4 -3 -2,8 -2,5 -2,3 etc.% dosage schedule. The dose-related respiratory depression was of lesser degree, than with fentanyl, and was equal to that with halothane. It was found an also dose-related saving in muscle relaxants. The blood sugar level increased considerably and more prolonged, than with the control anaesthetics. The high cost of the isoflurane (and of any other inhalational agent) was partly compensated by using it in a closed system. Authors found the isoflurane--based on their own experiences and on the data of the literature--suitable for prolonged and repeated anaesthesias too, but they referred to the circumstances also, which required closer attention.

[A modified method of anesthesia without intubation in microsurgical treatment of the larynx]. / Modifiziertes Verfahren der ohne Intubation ausgeführten Anaesthesie bei laryngomikroskopischen Eingriffen.

An anaesthetic method without intubation has been used for the first time in Hungary in 107 laryngomicroscopic operations. The method includes: Vagolytic, analgetic, sedative, vasodilatator, coronary flow enhancing, antihypertensive and antitussive premedication. Administration of the sedative anaesthetic gamma-OH, void of respiratory depression, in doses of 60 mg/kg body weight (given in 2 portions), combined with diazepam, without relaxation and intubation. Supplemental analgesia and inhibition of reflexes by means of mucosal and nerve-block anaesthesia. The premedication, supplemented by endonasal nitroglycerin, reduced the increase of blood pressure, which is a characteristic feature of laryngomicroscopic operations. The combined premedication was found to be effective as well in preventing the usual cardiac arrhythmias, partly reflectory, partly due to the depression of the sinus node (sick sinus syndrome). Nevertheless, the authors emphasize the importance of continuous ECG monitoring. Operation conditions met requirements in 102 cases (intubation had to be performed in 5 patients). The method's primary field of indication includes the microsurgical manipulation of glottic synechiae, as well of lesions in the interarytenoid space or on the vocal processes. Except for the removal of bleeding papillomas, haemangiomas or cysts, the method is expedient for the microsurgical therapy of benign changes, as well as for the topical diagnosis of malignant neoplasms in other laryngeal structures. The advantages of the method are safety, maintenance of normal oxygenation, easy prevention of aspiration, as well as good visibility and photodocumentation of the free operation field, undisturbed manipulation without time limit and, last but not least, simple performance requiring no additional expensive equipment.