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Biomedical subjects

W R Dukelow

Publications and source records attributed to W R Dukelow.

At least 55 records · Page 3Linked to original sources
PubMed1981

Xenogenous fertilization of laboratory and domestic animals in the oviduct of the pseudopregnant rabbit.

Xenogenous fertilization was accomplished using bovine, porcine, and hamster follicular oocytes. The xenogenous fertilization rates for bovine and porcine follicular oocytes in the oviduct of the pseudopregnant rabbit were 13.4% and 2.0%, respectively. Temperatures of ovary, during transport to the laboratory, of 0 degrees or 37 degrees C had no effect on xenogenous fertilization rates of bovine oocytes. In vitro culture in 50 mug/ml FSH did not alter the xenogenous fertilization rates of bovine oocytes. Fertilization was observed with oocytes recovered 40 to 75 hr after insemination. Two cell embryos were recovered 70 to 75 hr after insemination. Ligation of the rabbit oviduct, number of ova deposited and sperm concentration did not affect the xenogenous fertilization rates of hamster ova. Cleavage of xenogenously fertilized hamster oocytes occurred between 28 and 29 hours after insemination.

Journal Article↗
PubMed1981

Characteristics of the menstrual cycle in nonhuman primates. IV. Timed mating in Macaca nemestrina.

The events of the perineal swelling cycle in Macaca nemestrina have been correlated with the optimal time for conception. The mean cycle length of the animals was 32.8 days with the follicular and luteal phases of the cycle 17.6-19.2 and 13.6-15.2 days respectively. The time of ovulation, relative to the tumescence peak, ranged from 1 to 13 days. The optimal time for mating, based on the ratio between day of breeding and cycle length was 0.46, a value comparable with similar calculations for other macaque species.

Animals↗
PubMed1981

Chorionic surface area in conceptuses from sows treated with progesterone and oestrogen during early pregnancy.

Treatment of sows with 25 mg progesterone and 12.5 microgram oestrone daily between 14 and 23 days of gestation resulted in an increase of 15% of chorionic surface area and an increase in volume of allantoic fluid when examined at 30-35 days of gestation. In contrast, there were no significant differences in chorionic surface area or allantoic fluid volume between treated and control sows examined at 46-50 days of gestation. This suggests that progesterone-oestrone treatment of the sows during early pregnancy has only a short-lived effect on development of the allantochorion.

Allantois↗
PubMed1981

Fertilizability of ova from young or old hamsters after spontaneous or induced ovulation.

Young or aged hamsters, subjected to spontaneous or induced ovulation, were examined for ovulation rate, fertilization rate, and chromosomal normality. The fertilization rate in aged animals was decreased but there were no differences in ovulation rate. Abnormal chromosomes and degenerated oocytes occurred in the aged animals after induced ovulation. The fertilizing ability of sperm incubated in the uteri of young or aging animals showed no obvious differences when used for in vitro fertilization. These results indicated that defective ova represent one of the major factors leading to increased preimplantation loss in aged animals and also that superovulation of aged animals results in no beneficial effect, over spontaneous ovulation, on the fertilization process.

Age Factors↗
PubMed1980

Characteristics of the menstrual cycle in nonhuman primates. III. Timed mating in Macaca arctoides.

Analysis of five years of reproductive data from Macaca arctoides showed the mean menstrual cycle length was 29.9 +/- 4.4 days. Using timed mating, a conception rate of 16.3% was observed. The highest conception rate occurred after matings on day 11 of the cycle. Eight pregnancies went to term and the mean gestation length was 172.4 days. The sex ratio was 137.8 males per 100 females in fetuses obtained on day 100 post-conception.

Animals↗
PubMed1980

A research technique for the oviductal insemination of pigs using laparoscopy.

Nine postpubertal female pigs were inseminated with 0.1-2.0 ml of frozen-thawed semen via the oviductal lumen using laparoscopy. Two of the nine became pregnant. One gilt was subjected to hysterectomy at 30 days of gestation and five embryos were recovered. The second gilt was allowed to go to term and delivered two offspring, one of which grew to adult size. This procedure may have application for basic studies of sperm and egg physiology and may be adapted to other animal species.

Animals↗
PubMed1979

Characteristics of the menstrual cycle in nonhuman primates. I. Similarities and dissimilarities between Macaca fascicularis and Macaca arctoides.

Comparative studies of reproductive characteristics were carried out on a colony of Macaca fascicularis and M. arctoides. Seasonal differences were not significant between species, and conceptions occurred throughout the year. The occurrence of short cycles ('luteal phase defect') was found in 2.9% of all M. fascicularis cycles and 1.5% of all M. arctoides cycles. Long cycles (40-50 days) were found in 4.0% of all M. fascicularis cycles and 3.5% of all M. arctoides cycles. Gestation lengths averaged 172.4 and 165.3 days, respectively, for M. arctoides and M. fascicularis. Ovulation in M. fascicularis occurred at a day of ovulation/cycle length ratio of 0.48 +/- 0.08 compared with 0.48 +/- 0.09 for M. mulatta data previously published.

Animals↗
PubMed1979

Characteristics of the menstrual cycle in nonhuman primates. II. Ovulation and optimal mating times in macaques.

An analysis of the results of 1,259 limited-duration matings was conducted on colonies of Macaca arctoides and M. fascicularis. Maximum conception occurred at a day of breeding/cycle length (DB/CL) ratio of 0.40--0.41 with a range of DB/CL ratios for successful matings from 0.39 to 0.44. These values are compared with published values for various endocrine parameters equated to cycle length.

Animals↗
PubMed1979

Seasonal variation of reproductive parameters in the laboratory-housed male cynomologus macaque (Macaca fascicularis).

Changes in body weight, sperm concentration and testicular volume were monitored for a 13-lunar month period in seven laboratory-housed adult male Macaca fascicularis. No significant change was noted in body weight or sperm concentration between periods of maximal and minimal mean values nor between periods standardized for comparison between the three parameters. Testis volumes were significantly greater during the months of July through early September and during the standardized period of May through July than during January through March and the standardized interval October through January.

Animals↗
PubMed1978

Possible errors in identification of squirrel monkeys (Saimiri sciureus) from different South American points of export.

We conducted karyological studies on one colony consisting of 12 Colombian and 34 Bolivian squirrel monkeys and a second colony of 47 monkeys imported into the United States between 1968 and 1974 through six importers. All animals in the first colony showed six acrocentric pairs of chromosomes. Bolivian monkeys were phenotypically distinguishable by their large size and coloration. In the second colony, 19 Peruvian, seven Colombian, five Bolivian and six Guyanan monkeys were correctly identified phenotypically and had five, six, six, and seven acrocentric pairs of chromosomes, respectively. Among Peruvian monkeys, 34.5% of the phenotypic classifications were in error.

Animals↗