Induction of the endogenous gonadotrophin surge for oocyte maturation with intra-nasal gonadotrophin-releasing hormone analogue (buserelin): effective minimal dose

From 1985-1987, a total of 34 couples undergoing superovulation for a single in-vitro fertilization (IVF) cycle with clomiphene citrate and purified follicle stimulating hormone (FSH) or human menopausal gonadotrophin (HMG) were randomly allocated doses of intra-nasal buserelin to induce an endogenous gonadotrophin surge, prior to oocyte collection. The doses ranged from a single 25 microg dose to 100 microg every 4 h for 20 h. In three cycles the treatment was abandoned because of a poor ovarian response. In the remaining 31 cycles buserelin was given to induce the endogenous gonadotrophin surge, but there was evidence of premature luteinization in eight cycles and a premature gonadotrophin surge in four cycles. Although a single dose as low as 40 microg induced a surge and resulted in a pregnancy, a single dose of 50 microg proved the most effective minimal dose consistently to induce a gonadotrophin surge and oocyte maturation. Recent reports using gonadotrophin-releasing hormone (GnRH) analogues to induce a gonadotrophin surge has prompted publication of this previously unpublished data.      

ACTION OF CHOLINESTERS ON SENSORY NERVE ENDINGS IN SKIN AND MUSCLE

1. This is a review of the literature on the subject of the effects of cholinesters and their agonists on sensory nerve endings. 2. The present-day view is that acetylcholine (ACh) has an excitatory action on some cutaneous receptors. Responses appear to be limited to receptors served by small myelinated and un-myelinated axons where responsiveness is multimodal; that is, the receptors are activated by noxious thermal and mechanical stimulation. 3. The possible role played by acetylcholine in sensory transduction processes is discussed, as are other explanations for the presence of nicotinic cholinergic receptors on the terminals of cutaneous receptors. 4. The excitatory action of ACh and succinylcholine (SCh) on muscle spindles is described. Two possible mechanisms are considered: a direct depolarizing action on the nerve terminals and indirect excitation, brought about by a contracture of the intrafusal fibres on which the sensory endings lie. 5. The technique of using SCh in combination with fusimotor stimulation is described. This has provided new information about the internal workings of muscle spindles. Brief mention is also made of the action of SCh on tendon organs and joint receptors. 6. It is concluded that a direct action by cholinesters is restricted to receptors served by small axons with multimodal functions. The precise role of such an action remains the subject of speculation. Possible clinical significance is discussed.     

Iopamidol arteriography: discomfort and pain

A double-blind, randomized study was performed to compare discomfort and pain associated with the use of iopamidol and Hypaque (diatrizoate sodium and diatrizoate meglumine) during iliofemoral runoff arteriography in 33 patients. Iopamidol caused substantially less discomfort and pain. The evaluation was helped by audiotaping the study and comparing patients' vocal responses to injections of these materials.