Current concepts in trauma: 2. The Sunnybrook Medical Centre trauma program: the first 11 years.

Sunnybrook Medical Centre is a tertiary care teaching hospital situated in metropolitan Toronto. Its trauma unit, opened in June 1976, serves the inhabitants of metropolitan Toronto and the surrounding area (approximately 5 million). More than 3200 patients were admitted to the unit between 1976 and 1987. The criteria for admission were age at least 14 years and an Injury Severity Score (ISS) of 16 or greater, two or more significant injuries at anatomically discrete sites when the score on the Abbreviated Injury Scale was 3 or greater, or grade IV shock (systolic blood pressure of 80 mm Hg or less). The number of patients admitted annually to the unit increased over the study period. The survival rate also increased, from 76% in 1976 to 88% in 1987, although the average age and ISS of the patients remained unchanged. Less than 2% of the patients required long-term rehabilitative or chronic care. The patient profile is similar to that seen in other trauma centres in North America. The success of this program is largely the result of expeditious stabilization and transfer from referring hospitals coupled with early definitive surgical intervention.     

Maternal and neonatal outcome in pregnancies with no risk factors.

Between November 1979 and April 1984, 790 consecutive pregnant women who considered themselves as having a "normal" pregnancy were followed in private practice from 9 weeks'' gestation until 6 weeks post partum. The women had no pre-existing disease or problem classified as a risk to the pregnancy at the time of their first visit, had a singleton pregnancy and gave birth at Notre-Dame Hospital, Montreal. Maternal complications occurred during the course of pregnancy in 181 women (23%). Complications were mostly related to obstetric conditions (10%), such as preterm labour, intrauterine growth retardation (IUGR) and antepartum hemorrhage, or to medical conditions (12%), the most prevalent of which was hypertension (77% of medical conditions). Neonatal complications occurred in 183 infants (23%). The corrected perinatal death rate was 2.5 per 1000. Prematurity, IUGR and dysmaturity/postmaturity accounted for nearly half of the complications. Hyperbilirubinemia occurred in 7% of the cases. Among women without any maternal complications during pregnancy, the frequency rate of neonatal complications was 19%, compared with 23% among the entire group of 790 women. Our results suggest that the absence of maternal complications does not protect the infant from a neonatal complication. Further refinement is needed to identify markers of obstetric, medical and neonatal complications in pregnancies with no risk factors.     

The outcome of twin pregnancies in mares

Brood-farm veterinarians were surveyed and theriogenology records were examined to obtain information on the natural outcome of rectally-diagnosed twin pregnancies. Four of the veterinarians estimated that 50% of mares with twin embryos had single foals. In the analyses of palpation records, 31 53 (58%) of the diagnosed twin pregnancies terminated in birth of one foal. However, the loss of one embryo without the loss of the other occurred significantly more often before day 40-42 (30 53 ; 57%) than after day 40-42 (1 16 ; 6%). Of the remaining 15 mares with diagnosed twins at day 40-42, 5 had two foals and 10 had no foals. The methods used for intervention when twins were diagnosed were unsatisfactory. Complete termination of pregnancy with a prostaglandin or an intrauterine flushing resulted in failure to reestablish a singleton pregnancy during the operational breeding season in 10 11 mares. Attempts to eliminate one embryo resulted in loss of both in 6 7 mares. The results indicated that, at the present time, nonintervention should be given more consideration as a method of handling twin pregnancies.     

Inhibition of in-vitro fertilization of intact and denuded hamster eggs by univalent anti-sperm antibodies.

Univalent (Fab) rabbit anti-hamster sperm antibodies added to an in-vitro fertilization system did not interfere with the sperm acrosome reaction or motility, but inhibited cumulus dispersion by the spermatozoa, sperm binding to and passage through the zona pellucida as well as sperm-egg fusion. Addition of the Fab preparations to the capacitated spermatozoa at various times before or up to 40-45 min after the sperm-egg mixing prevented penetration of spermatozoa through the zona pellucida. Detachment of the spermatozoa already bound as well as those partly inside the zona pellucida was achieved by a late addition of antibodies. In experiments with zona-free hamster eggs, addition of the Fab antibodies to the spermatozoa 10 min to 5 h before the introduction of unfertilized eggs reduced the rate of adhesion and fertilization to very low levels. These antibodies were not absorbed on hamster ovary, liver or kidney and had no direct effect on the fertilizability of zona-intact or zona-free eggs.     

Success of a program of routine prenatal screening for hepatitis B surface antigen: the first 2 years.

Prenatal screening for hepatitis B surface antigen (HBsAg) restricted to women with defined risk factors for chronic hepatitis B virus (HBV) infection fails to identify many carriers. A centralized program of routine HBsAg screening for all pregnant women in Alberta was introduced in 1985. We collected and analysed data for the first 2 years of the program in Edmonton to determine the frequency of risk factors for HBsAg positivity, the proportion of multiparous HBsAg-positive women not identified in previous pregnancies, the efficiency and cost-effectiveness of providing immunoprophylaxis to infants at risk of HBV infection and the degree of success in inducing adequate protection. A total of 149 women (158 pregnancies) were found to be HBsAg positive. Risk factors were readily ascertainable for 85% of the women; the remaining 15% would not have been identified through risk-selective screening. The most common risk factors were Oriental ethnic origin, history of hepatitis, jaundice or multiple transfusions of blood or blood products, and occupational exposure to blood. Although 86% of the multiparous HBsAg-positive women had risk factors, only 7% had been identified in previous pregnancies. The Alberta program appears to be cost-effective. We conclude that only routine prenatal screening will identify all infants at risk of perinatal HBV infection and that a comprehensive public health program involving central laboratories, private physicians and public health staff can be highly effective and efficient in protecting infants against hepatitis B.     

In vitro fertilization of bovine oocytes in in-vitro protein-free culture system

We studied the possibility of fertilization of bovine oocyte-cumulus complexes, matured in vitro in a protein-free medium, in a protein-free culture system without preliminary capacitation of spermatozoa. The development of embryos to the morula-blastocyst and blastocyst stage was considered as a criterion of successful fertilization. It was shown that replacement of bovine serum albumin for polyvinyl alcohol or polyvinylpyrrolidone in Tyrode medium for fertilization did not affect significantly the development to the morula-blastocyst stage and the number of cells in blastocysts. It was also found that replacement bovine serum albumin for polyvinyl alcohol in all used media, Tyrode medium for washing of oocytes, medium for sperm preparation to fertilization, and Tyrode medium for fertilization, did not affect significantly the development to the morula-blastocyst and blastocyst stages, as well as on the number of cells in blastocysts. The results obtained suggest that in vitro fertilization of bovine oocyte-cumulus complexes is possible in a protein-free culture system without significant reduction in the capacity for in vitro development of the obtained embryos and number of cells in blastocysts.     

A first formal link between the price equation and an optimization program

The Darwin unification project is pursued. A meta-model encompassing an important class of population genetic models is formed by adding an abstract model of the number of successful gametes to the Price equation under uncertainty. A class of optimization programs are defined to represent the "individual-as-maximizing-agent analogy" in a general way. It is then shown that for each population genetic model there is a corresponding optimization program with which formal links can be established. These links provide a secure logical foundation for the commonplace biological principle that natural selection leads organisms to act as if maximizing their "fitness", provides a definition of "fitness", and clarifies the limitations of that principle. The situations covered do not include frequency dependence or social behaviour, but the approach is capable of extension.     

Serum inhibin as an index of ovarian function in women undergoing pituitary suppression and ovarian stimulation in an in vitro fertilization program.

Serum inhibin concentrations, determined by radioimmunoassay, were measured in women undergoing pituitary suppression with buserelin and subsequently ovarian stimulation with human menopausal gonadotropin (hMG). Three types of treatment cycle were investigated, namely (1) cycles showing a normal ovarian response and resulting in a pregnancy; (2) cycles showing a poor response to the hMG, and (3) cycles previously showing a poor ovarian response but augmented with biosynthetic human growth hormone. Good correlations were seen between serum inhibin concentrations and serum progesterone in the luteal phase prior to buserelin (Rs = 0.68), serum oestradiol on the 8th day of hMG administration (Rs = 0.82) or the day of ovulatory trigger (Rs = 0.78), and the number of follicles greater than or equal to 14 mm on the day of ovulatory trigger (Rs = 0.71). These results show inhibin to be a good index of ovarian function in women exhibiting a range of ovarian responses to stimulation in an in vitro fertilization program.     

Prognosis of subsequent pregnancies after recurrent spontaneous abortion in first trimester.

The outcome of subsequent pregnancies was studied in 24 women with a history of three or more consecutive spontaneous abortions in the first trimester. Twenty one of the women agreed to forgo active treatment during the study period and three received progestogens or surgical intervention. As the outcome of their first pregnancy after recurrent abortion 18 of the 24 women delivered a liveborn infant after 28 weeks or more. Of all 49 pregnancies in the untreated group during the study, 10 ended in abortion. Only one woman in the study failed to achieve a live birth. Except in exceptional cases encouraging women with recurrent abortion to keep trying for a successful outcome is just as effective as currently recommended treatments.     

The first 10 years of the dialysis-transplantation program at The Hospital for Sick Children,Toronto. 1: Predialysis and dialysis.

Renal dialysis and transplantation have been used for many years for adults with kidney failure but only recently for children. In May 1967 a renal-dialysis-transplantation program was established at The Hospital for Sick Children, Toronto for patients aged 6 to 18 years living within 240 km of Toronto. In 1973, children aged 1 to 5 years began to be accepted into the program, and by August 1977, 90 children (mean age 11 years) from all parts of Canada had been admitted to the program. The creation of vascular access in very small patients is difficult; the most successful types of access have been central shunts (established above the knee or the elbow) and bovine grafts. Specially made dialysis equipment is necessary for young patients. Young children should only be accepted in a dialysis-transplantation program that has a medical staff expert in meeting the specific needs of such children.     

Ram-specific effects on in-vitro fertilization and cleavage of sheep oocytes matured in vitro

The present experiments were designed to identify possible male-specific effects on early embryonic development in vitro: Sheep oocytes were matured in vitro for 24-26 h and then fertilized in vitro using equal numbers of viable spermatozoa from 1 of 6 Clun Forest rams. At 15-18 h after insemination, oocytes were either fixed and examined for fertilization and polyspermy or further cultured in modified M 199 medium for 3 days in an oviduct epithelial co-culture system. There were significant differences in 5 separate trials between the rams with respect to the rate of fertilization, degree of polyspermy and cleavage rate after monospermic fertilization. The mean rate of fertilization varied from 89% in Ram B to 43% in Ram C while the percentage of polyspermic eggs varied from 5 to 34%. Both the absolute number of embryos cleaving to the 16-cell stage and the calculated percentage of monospermic eggs reaching the 16-cell stage differed markedly between groups of eggs fertilized by different rams. The results indicate that the development of sheep eggs in vitro is differentially affected by the ram from which the spermatozoa are collected.     

Time relations of squirrel monkey (Saimiri sciureus) sperm capacitation and ovum maturation in an in-vitro fertilization system

First polar body expulsion in the squirrel monkey ovum occurred at an average of 13.1 h after hCG injection when observed in culture but could occur as early as 5 h after hCG. the mean time for extrusion of the second polar body was 4.7 h after insemination of the culture with freshly ejaculated spermatozoa (16.3 h after hCG). The earliest time, and therefore also that of sperm capacitation, was 2 h after insemination. First cleavage occurred 16.2 h after insemination.