Increased production of sheep embryos following superovulation of Merino ewes with a combination of pregnant mare serum gonadotrophin and follicle stimulating hormone.

In a factorially designed experiment (N = 321), 0, 800 or 1600 I.U. pregnant mare serum gonadotrophin (PMSG) were administered in combination with 0, 12 or 18 mg follicle stimulating hormone (FSH-P) to superovulate Merino ewes in autumn and spring. A moderate dose of PMSG (800 I.U.) in conjunction with 12 or 18 mg FSH-P increased the ovulation rate above that observed when FSH-P was used alone. This was accomplished by (i) increasing the proportion of ewes that exhibited a superovulatory response (greater than 3 corpora lutea (CL) or persistent large follicles (LF): 69/70 (99%) v. 55/74 (74%), P less than 0.001), and (ii) in those ewes that exhibited a superovulatory response, by an additive effect of exogenous gonadotrophin (14.8 +/- 0.9 CL (69) v. 11.3 +/- 0.9 CL (55), P less than 0.01) without increasing the incidence of LF. The use of 1600 I.U. PMSG in conjunction with 12 or 18 mg FSH-P was characterized by an increase in the number of LF and, in comparison with 800 I.U. PMSG, a reduction in ovulation rate. Season had no effect on the numbers of CL, but total ovarian response (CL + LF) was higher in autumn than in spring (P less than 0.01), because of a greater incidence of LF (P less than 0.001). The proportion of ewes with regressed CL was higher in autumn than in spring (53/143 (37%) v. 32/156 (21%), P less than 0.01), and increased with increased dose of gonadotrophin. Furthermore, a nutritional component to the incidence of ewes with regressed CL was suggested by the observation that the mean concentration of plasma glucose was higher for ewes with normal CL than for ewes with regressed CL (P less than 0.05). Rates of ova or embryo recovery, fertilization and embryo development generally declined with an increase in the incidence of LF as a result of increases in the dose of gonadotrophin and season of administration.

Time of ovulation in merino ewes superovulated with PMSG and FSH-P.

An experiment examined the effects of treatment with gonadotrophin releasing hormone (100 micrograms GnRH injected 24 h after progestagen sponge removal), season of treatment (autumn v. spring), the effect of supplementary feeding with lupin grain (in autumn only, from 12 days before until 8 days after sponge removal) on the time of ovulation in 182 mature Merino ewes superovulated with a combination of 400 I.U. pregnant mare serum gonadotrophin (PMSG) and 12 mg follicle stimulating hormone (FSH-P). Time of ovulation was influenced by both season and the administration of GnRH. Two peaks of ovulation were observed in spring, the first between 24 and 30 h after sponge removal, and the second commencing 42 h after sponge removal. In autumn, there was one peak of ovulation between 42 and 54 h after sponge removal. Treatment with GnRH advanced the time of ovulation in autumn (P less than 0.05), but had no apparent effect in spring. In contrast to the effect of GnRH, time of ovulation for ewes treated in autumn was delayed (P less than 0.001) by supplementary feeding with lupins.

Season affects characteristics of the pre-ovulatory LH surge and embryo viability in superovulated ewes.

The aim of this study was to determine whether there are seasonal shifts in ovulatory response, and in the viability of ova recovered from superovulated ewes. Fifty mature ewes underwent a standard oestrous synchronisation (CIDR), superovulation (oFSH) and artificial insemination procedure during October (peak breeding season) and April (transition to anoestrus). In each month peripheral LH and progesterone concentrations were measured around the time of ovulation and embryos were recovered, graded and cryopreserved on day 6 after insemination. During the subsequent breeding season, grade 1 and 2 morulae and unexpanded blastocysts were thawed and transferred singly to synchronous recipients (October, n = 40; April, n = 40) or cultured in vitro for 18-20 h (October, n = 107; April, n = 98). Following culture, viable embryos were stained to count cell nuclei or assayed to measure their capacity for glucose metabolism ([3H]glucose) and protein synthesis ([35S]methionine). Peak LH concentrations were higher in October than in April (38.2 +/- 3.26 ng ml(-1) versus 25.7 +/- 1.99 ng ml(-1), respectively; P < 0.01) and the pre-ovulatory LH surge was advanced by approximately 3 h (P < 0.05). Progesterone concentrations at CIDR withdrawal were lower in October than in April (3.1 +/- 0.16 ng ml(-1) versus 4.3 +/- 0.19 ng ml(-1), respectively; P < 0.001) but were not different at embryo recovery. Season did not affect the numbers of corpora lutea per ewe or the numbers of ova recovered but the proportion of recovered ova that was unfertilised/degenerate was lower in October than in April (0.43 versus 0.58, respectively; P < 0.001). For embryos containing more than 16 cells, there was no effect of season on the median stage of development or morphological grade. The proportions of October and April embryos that established pregnancy following transfer to recipient ewes were 0.78 and 0.70 (not significantly different), and that were viable after in vitro culture were 0.66 and 0.37 (P < 0.05), respectively. Season did not affect the number of nuclei per viable embryo or the capacity for protein synthesis but the glucose uptake of October embryos was approximately double that of April embryos (3163+/-293.4 dpm versus 1550+/-358.9 dpm, respectively; P < 0.05). Results indicate that during the late compared to peak breeding season, there is an increased incidence of fertilisation failure as a possible consequence of seasonal shifts in LH secretion and (or) associated effects on follicular function. Frozen-thawed embryos produced at contrasting stages of the breeding season are equally viable in vivo but those produced during the late, as opposed to the peak breeding season have lower viability following in vitro culture.

The value of voice in participative decision making.

Relying on concepts found in prospect theory (D. Kahneman & A. Tversky, 1979), the value function of voice-based participation (i.e., the relationship between the amount of voice received and the value attached to that quantity) was examined. In keeping with tenets of prospect theory, the value function of voice exhibited a nonlinear pattern. Points were identified in which voice displayed significant improvements and diminishing marginal returns on response measures of process fairness, decision control, and outcome satisfaction. Task meaningfulness, a moderator of voice-based participation, did not change the general shape of the value function but did influence the intensity of participant reactions at low and high levels of voice. Voice influence, a second moderator of voice-based participation, had minimal impact on participant responses.

The use of procaine hydrochloride as a continuous lumbar epidural technique in labour.

A continuous technique for lumbar epidural during labour is described, using procaine hydrochloride without adrenaline. An investigation was undertaken to determine the action of procaine in labour, to determine whether this drug could facilitate a normal delivery and to study maternal and fetal blood procaine levels. The technique, although successful, offered no specific advantages.

Reversible paraplegia following coeliac plexus block.

Permanent paraplegia following coeliac plexus block has been reported on several occasions. We report a case of reversible paraplegia following coeliac plexus block.

Metal tube anaesthesia for ear, nose and throat carbon dioxide laser surgery.

Tracheal tube anaesthesia in ear, nose and throat surgery using the carbon dioxide laser is reviewed. The development of metal tubes and techniques is described.

Anaesthetic management for carbon dioxide laser surgery in tracheobronchial lesions.

There are technical difficulties associated with anaesthesia in patients who undergo laser surgery to the trachea and main bronchi using the carbon dioxide laser. An anaesthetic technique using spontaneous ventilation is described which has been used successfully in 33 patients.

Anaesthesia for carbon dioxide laser laryngeal surgery in infants. A new tracheal tube.

Problems associated with the presence of a tracheal tube during anaesthesia for infant laryngeal surgery using the carbon dioxide laser are described. This paper discusses alternatives and describes an effective anaesthetic technique and a new tracheal tube.

Features of the Value Function for Voice and Their Consistency across Participants from Four Countries: Great Britain, Mexico, The Netherlands, and the United States.

This study investigated features of the value function for voice using subjects from four countries: Great Britain, Mexico, The Netherlands, and the United States. Across these four groups of subjects the shape of the value function was found to be similar, though differences in the estimated reference points were detected. Consistent with predictions derived from prospect theory (Kahneman & Tversky, 1979) the relationship between the value of voice and the magnitude of voice was found to be direct, monotonic, and nonlinear. The largest increment in value occurred when the magnitude of voice shifted from mute to some voice. Thereafter, increments in value tended to decline in magnitude suggesting diminishing marginal returns on the response measure of procedural fairness. An unexpected finding was that the final segment of the value function was convex indicating increasing marginal returns as the magnitude of voice shifted from its penultimate level to its maximum possible level. The study also investigated whether subjects' reported expectations of voice correspond to the value function reference point as theorized in the literature. Findings suggest that self-reported expectations of voice are higher than the estimated value function reference point.