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G. L. FOSS and F. J. W. LEWIS

Summary.

Four unusual cases of Klinefelter's syndrome are described, in which motile spermatozoa were found in several ejaculates. One of these subjects was shown to be a 47XXY/46XY mosaic, but intensive cytogenic studies in the other three failed to reveal evidence of this. Records of proven parenthood may eventually disturb the present concept of sterility in this condition.

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G. L. FOSS, J. B. HOLTON and F. J. W. LEWIS

Oral contraceptives containing oestrogen and progestagen in high dosage may produce many undesirable side effects. The risk of thrombo-phlebotic episodes (Vessey & Doll, 1969) has caused much concern, but the possible long-term effects of the numerous metabolic changes have also to be considered. Amongst the latter, impaired glucose tolerance (Wynn & Doar, 1969) and increased levels of serum glutamic—pyruvate transaminase (SGPT) have been reported (Larsson-Cohn, 1965).

The use of norgestrel alone, given continuously in low dosage of 50 μg, is slightly less effective as a contraceptive than conventional combinations of oestrogen and progestagen (Foss, Svendsen, Fotherby & Richards, 1968) and 22% of cycles are shorter than 23 days in the women on this regimen, but the incidence of side effects is much lower (Foss, 1968). With the elimination of the

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C. L. Chatot, C. A. Ziomek, B. D. Bavister, J. L. Lewis and I. Torres

Summary. One-cell CF-1 × B6SJLF1/J embryos, which usually exhibit a 2-cell block to development in vitro, have been cultured to the blastocyst stage using CZB medium and a glucose washing procedure. CZB medium is a further modification of modified BMOC-2 containing an increased lactate/pyruvate ratio of 116, 1 mm-glutamine and 0·1 mm-EDTA but lacking glucose. Continuous culture of one-cell embryos in CZB medium allowed 83% of embryos to develop beyond the 2-cell stage of which 63% were morulae at 72 h of culture, but blastocysts did not develop. However, washing embryos into CZB medium containing glucose after 48 h of culture (3-4-cell stage) was sufficient to allow development to proceed, with 48% of embryos reaching the blastocyst stage by 96 h of culture. Exposure of embryos to glucose was only necessary from the 3–4-cell stage through the early morula stage since washing back into medium CZB without glucose at 72 h of culture still promoted the development of 50% of embryos to the blastocyst stage. The presence of glucose in this medium for the first 48 h of culture (1-cell to 4-cell stage) was detrimental to embryo development. Glutamine, however, exerted a beneficial effect on embryo development from the 1-cell to the 4-cell stage although its presence was not required for development to proceed during the final 48 h of culture. Blastocysts which developed under optimum conditions contained an average of 33·7 total cells. The in-vitro development of 1-cell embryos beyond the 2-cell stage in response to the removal of glucose and the addition of glutamine to the culture medium suggests that glucose may block some essential metabolic process, and that glutamine may be a preferred energy substrate during early development for these mouse embryos.

Keywords: mouse; embryo; 2-cell block; glutamine; glucose

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G. L. FOSS, E. T. BELL, F. J. W. LEWIS, J. A. LORAINE and B. R. POLLARD

Summary.

The effect of clomiphene on the sperm count and hormone excretion is described in a patient with Klinefelter's syndrome, having a 47 XXY karyotype, and in whom a testicular biopsy showed small areas of spermatogenesis.

Clomiphene stimulated the production of morphologically normal motile spermatozoa in the absence of any marked effect on hormone output.

Possible explanations for these findings are discussed.

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A. M. Schmidt, D. L. Hess, M. J. Schmidt, R. C. Smith and C. R. Lewis

Summary. Three mature nulliparous female leopards were studied for 5 years. During three separate 6-month periods serum oestradiol and progesterone concentrations were measured at weekly intervals. Oestradiol was elevated over 21 pg/ml for 54 weeks during these 3 periods, and 36 oestradiol peaks (65·8 ± 6·3 pg/ml (mean ± s.e.m.), range 21–172 pg/ml) were identified. Daily frequency of feline reproductive behaviours averaged over each week increased from 1·9 ± 0·2 (n = 93) during weeks with low serum oestradiol concentrations (<21 pg/ml) to 5·3 ± 0·6 (n = 54) during weeks when serum oestradiol concentrations (>21 pg/ml) were high.

Increased serum progesterone concentrations (13–98 n/gml) were observed on 5 occasions in 2 leopards housed together. These presumptive luteal phases lasted from 1 to 5 weeks. Baseline progesterone values were 1·6 ± 0·4 ng/ml (n = 131). No progesterone increments were observed in isolated animals, and serum concentrations remained at baseline levels. These limited observations suggest that female leopards do not require intromission to induce ovulation and luteal function.

The average interval between oestradiol peaks for cycles with no progesterone increment was 3·4 weeks (range 1–6 weeks). The interval for the 3 complete cycles associated with elevated progesterone concentrations was 7·3 weeks. Analysis of sexual behaviours over the 5-year study period revealed no evidence of seasonality in these captive leopards.

Keywords: oestradiol; progesterone; behaviour; leopard; oestrous cycle

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A. M. Schmidt, D. L. Hess, M. J. Schmidt and C. R. Lewis

Serum oestradiol and progesterone concentrations were measured at weekly intervals for six months, and correlated with daily behavioural observations in two adult female snow leopards (Panthera uncia). Three oestradiol peaks (>21 pg ml−1; interval 3.6 weeks) were identified in a snow leopardess housed alone (two more were probably missed because of the weekly sampling schedule), and three oestradiol peaks were identified in a snow leopardess housed with a male as a breeding pair (interval 6 weeks). Daily frequencies of feline reproductive behaviour averaged 1.77 observations per observation period during weeks of high oestradiol and 0.62 during weeks of low oestradiol. Progesterone concentrations did not rise above baseline values (< 2 ng ml−1) in the isolated animal, but 6 weeks of high progesterone concentrations 4.9–38.8 ng ml−1) was recorded in the paired snow leopardess following mating. No offspring were produced. Snow leopards were observed daily for an additional 4.5 years. Sexual behaviour peaks could be clearly identified from December through April, and average daily sexual behaviour scores were higher during these months than during the rest of the year. Intervals between sexual behaviour peaks for the isolated snow leopardess averaged 3.03 weeks. The sexual behaviour of the paired snow leopards decreased for 8–9 weeks following mating when no offspring were produced, and decreased for 13 weeks in one year when a single cub was born.