TOBRAMYCIN AND NEUROMUSCULAR TRANSMISSION IN THE RAT ISOLATED PHRENIC NERVE-DIAPHRAGM PREPARATION

The effects of different concentrations of tobramycin, streptomycin,neomycin and gentamicin on the rat isolated phrenic nerve-diaphragmpreparation are reported. Streptomycin, neomycin and gentamicinproduced dose-dependent neuromuscular blockade. Tobramycin increasedthe muscle response at high concentrations (6.4 x 10^–4–2.6x 10^–2 mol litre^–1), but had no detectable effectwhen used in therapeutically recommended concentrations.     

Economy in the use of muscle relaxants Vecuronium after pancuronium

Vecuronium is an intermediate duration, non-depolarising muscle relaxant. When used during prolonged procedures, it may be given by intermittent injection, by continuous infusion or by a single very large dose at the start of anaesthesia. It may also be used to maintain relaxation after the initial use of a long-acting agent, such as pancuronium. This study demonstrates that the effect of a dose of vecuronium used in this fashion is increased when interaction with pancuronium takes place. The clinical and theoretical implications of this observation are discussed.     

Clinical aspects of LHRH analogues in gynaecology: a review

Summary. LHRH agonists are synthetic peptide analogues of hypothalamic luteinizing hormone releasing hormone (LHRH) with superior potency and longer duration of gonadotrophin release. Paradoxically, repeated administration causes pituitary desensitization with diminished gonadotrophin and oestradiol secretion. A state of hypogonadotrophic hypogonadism is reversibly induced; plasma oestrogen can be reduced to castrate levels. LHRH agonists reliably induce anovulation but are unlikely to replace existing contraceptive methods in most normal women. By contrast these agents offer, for the first time, the prospect of inducing a reversible pseudomenopause essentially free of side-effects. LHRH analogues promise to have a profound impact upon the management of a diverse range of oestrogen-dependent gynaecological diseases both benign and malignant. In particular, they may shortly become the gynaecological treatment of choice in endometriosis, as well as becoming part of the management of common gynaecological disorders such as dysfunctional uterine bleeding and uterine fibroids.     

U.S. Experience with the AddVent VDD(R) Pacing System

The AddVent pacemaker generator and model 1328C AV single-pass lead is a new pacemaker system capable of VDD or VDDR modes. The purpose of this study was to present the initial experience with AddVent in the United States and Canada. Between May 10, 1995 and May 3, 1996, 53 devices were implanted in 52 patients and followed for a mean of 217 (±39) days. At the predischarge, 1-, 3-, and 6-month follow-up evaluations, atrial sensing thresholds and ventricular sensing and capture thresholds were measured in the supine, sitting, and standing positions to evaluate stability of atrial sensing with respect to body posture at rest. At the 1-month follow-up, a treadmill exercise test was performed to evaluate atrial sensing during exercise and to evaluate two new features of the AddVent called "sensor-mediated rate smoothing" and "preferential P wave sensing." Atrial sensing thresholds were not significantly different (P > 0.05) among body postures for any follow-up period or among follow-up periods for each posture. At rest, the percentage of appropriately tracked P waves observed was > 99% at each follow-up period. During treadmill exercise, the percentage of appropriately tracked P waves was > 98.7%. Appropriate preferential P wave sensing and sensor-mediated rate smoothing (VDDR mode) was observed. The AddVent pacing system provides safe and effective pacing therapy. Several features of VDDR pacing offer advantages over standard VDD pacing.     

Cancer of the pyriform fossa: hyperfractionated radiotherapy as a primary treatment modality

Carcinoma of the pyriform fossa carries one of the worst prognoses of all head and neck cancers. A prospective trial was set up to study the efficacy of hyperfractionated radiotherapy as a primary treatment modality in the management of these patients. Seventeen patients entered the trial and were followed for up to 3 years. Results for local control, regional control and survival compare favourably with patients treated primarily with surgery with or without radiotherapy. Hyperfractionated radiotherapy offers a logical and standardized approach to the management of this tumour and reduces the significant morbidity associated with the use of surgery as a primary treatment.