Formation and determination of aldehyde-addition products of tryptophan.
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Acetaldehyde↗
Biomedical subjects
C Karg
Publications and source records attributed to C Karg.
[Esmolol as a bolus for prevention of sympathetic adrenergic reactions following induction of anesthesia].
In addition to laryngoscopy, endotracheal intubation, and other stressful intraoperative phases, hypertension occurs during recovery from anaesthesia, provoking post-operative complications like bleeding and increased intracranial or intraocular pressure. Furthermore, these hypertensive reactions result in life-threatening complications, especially in patients with pre-existing cardiovascular diseases. In this study, the effect of the new, short-acting beta-blocker esmolol given as a single bolus for preventing the increases in blood pressure and heart rate during recovery from anaesthesia and extubation in patients with hypertension was investigated. PATIENTS AND METHODS. Sixty-three patients with a history of hypertension over a period of more than 6 months and blood pressure (BP) more than 150/90 mm Hg undergoing intervertebral-disc, otolaryngologic, or eye surgery were included in the study. The operations were performed during thiopentone-induced isoflurane anaesthesia with relaxation by atracurium. The patients were assigned to three groups after giving witnessed oral informed consent. During the study period they received the study drug twice: (A) 30-90 s before turning off the nitrous oxide; and (B) 20-90 s before extubation. Group I (placebo) received placebo each time, group II (100 mg esmolol) placebo at A and 100 mg esmolol i.v. at B, and group III (200 mg esmolol) 100 mg esmolol i.v. each time. After each medication the cardiovascular parameters were measured noninvasively over a period of 10 min every minute and in the following 2 h every 15 min. RESULTS. After the first medication systolic and diastolic BP, heart rate (HR), and rate-pressure product (RPP) were lower in patients receiving 100 mg esmolol (Group III) than in groups I and II. After the second injection the blood pressure was lower in the two groups receiving 100 mg esmolol, than the placebo group (I: 180.1 +/- 7.4/100.7 +/- 3.6; II: 152.8 +/- 5.8/87.9 +/- 3.4; III: 157.9 +/- 5.3/91.5 +/- 3.6 mm Hg [mean 2 min +/- SEM]). The changes in HR (I: 88.2 +/- 3.8; II: 75.6 +/- 2.6; III: 72 +/- 3.1 min-1) and RPP (I: 15,800 +/- 900; II: 11,700 +/- 700; III: 11,400 +/- 600) were similar. In 8 of the 20 patients in group III the HR dropped below 60.min-1, but in none of these patients did the BP become instable. CONCLUSIONS. The sympathoadrenergic reaction during recovery from anaesthesia and extubation can be treated by beta-blocking agents, but such therapy is not without risk because of the long half-life and effects of the therapy on other factors such as postoperative loss of intravascular volume. Esmolol is a new, short-acting, cardioselective beta-blocker with a very short plasma distribution time and a elimination half-life of 9.2 min. Thus, the potential risks of beta-blockers due to half-life are minimised. The results of this study show that a dangerous increase in BP and HR with increased myocardial oxygen consumption can be prevented by a single bolus, and better by a double bolus of 100 mg esmolol. Although bradycardia with HR below 50.min-1 in 8 patients might indicate a risk of cardiac instability, the systolic BP did not fall below 100 mm Hg, and the episode of bradycardia was so short that there was no risk to the patients.
Adrenergic beta-Antagonists↗
[Chemotherapy of malignant melanoma--current status].
Curative treatment modalities for patients with malignant melanoma (MM) in advanced stages are limited. Temporary successes with chemotherapy have so far mainly been achieved after removal of all accessible tumor masses. Extensive experience with cytostatic measures has been gained over more than two decades both with therapeutic and with adjuvant schedules. Dacarbazine (DTIC), which is associated with a remission rate of approximately 20%, continues to be the most effective cytostatic drug in the treatment of MM. Systemic (poly) chemotherapeutic schedules with and without DTIC have improved the response rates in metastasizing MM in numerous phase II trials. However, these results have not been confirmed in randomized studies comparing these schedules with DTIC monochemotherapy. For the BOLD schedule (bleomycin, Oncovin, lomustine, dacarbazine), the BELD schedule (Eldisine instead of Oncovin), and the DVP combination (dacarbazine, vindesine, Platinex), initial response rates of 40-49% have been reported. However, lower response rates were recently described (DVP: 24%; BOLD: 22% and 4%). Therefore, there is still no definite evidence that polychemotherapy is superior to DTIC monotherapy in MM. In our opinion, expected response rates of 20-30% justify the use of chemotherapy in disseminated MM; in cases of further progression, therapy should be interrupted early - after 2-3 cycles. Systemic (poly) chemotherapy of metastasizing MM is indicated in patients whose general condition is good, mainly in those who have skin, soft tissue, or lung metastases. These metastases usually respond well to cytostatic treatment. In future, the combined use of cytostatics together with new antitumour molecules may reduce the general toxicity and improve the efficacy of systemic cytostatic therapy in MM. The benefits of adjuvant chemotherapy in the treatment of MM have still to be confirmed definitively. While adjuvant therapy with DTIC has proved to be ineffective in stage I, irrespective of the tumor thickness, some studies suggest that adjuvant therapy with DTIC, or combinations including DTIC, may improve the prognosis of patients in clinical stage II.
Antineoplastic Agents↗