New thermal stress test to assess the viability of cryopreserved boar sperm.

A new, rapid, thermal stress test for assessing the viability of boar semen, requiring only 45 min of incubation at 42.5 degrees C, was developed and compared with a widely used stress test of 180 min incubation at 37 degrees C. The shorter procedure was found to have the same discriminatory ability as the standard test in assessing the effects of freezing conditions on the percentage of spermatozoa remaining motile.

Activation of cumulus-free mouse oocytes.

Attempts were made to activate parthenogenetically oocytes from random-bred mice under conditions required for nuclear transfer, viz. in the absence of cumulus cells. Of the large number of stimulants previously described and presumed to be generally effective, only exposure to strontium ion (as a replacement for calcium ion in the medium), or to calcium ionophore, activated a substantial proportion of cumulus-free oocytes from TRf mice, a synthetic, random-bred strain.

[ERCP in bile duct dilatation with jaundice due to spontaneous hydatid cyst rupture. Diagnosis, differential diagnosis, therapy and result].

We report the case of a 17 years old Turkish patient hospitalized for colics and jaundice. Ultrasound, computer tomography and ERC showed enlarged intra- and extrahepatic bile ducts. The further investigations documented the rupture of a hepatic hydatid cyst into the biliary tract with obstructive jaundice.

The synthesis and actions of steroids and prostaglandins during follicular maturation in the pig.

Our understanding of the synthesis and production of follicular steroids and prostaglandins (PG) in the pig is based largely on in-vitro studies with granulosa and theca interna tissues obtained from Graafian follicles at various stages of maturation. As the follicle enlarges before the LH surge, granulosa cells exhibit a decrease in FSH receptors and are less responsive to FSH in terms of cAMP production. Concurrently, there is an increase in granulosa and thecal cell LH receptors associated with an increase in responsiveness to LH and an increase in steroid production.

Continuous live-dead discrimination of ram sperm during freezing.

Use of the dye amaranth (Color Index 16185) as a supravital stain for ram sperm is described. At a concentration of 0.4% in diluted semen, the dye was completely excluded by motile sperm and had no effect on sperm motility.

Liability for the health of detainees.

District surgeons have a statutory duty to provide medical treatment to detainees held in terms of the State of Emergency. District surgeons enjoy no special protection or immunity by reason of their position. Accordingly, they may be held legally liable for the consequences of negligent treatment or the failure to treat when circumstances so demand.

Estradiol assay by microtitre plate enzyme immunoassay.

Development of a simple enzyme linked immunosorbent assay (ELISA) for estradiol in serum extracts is described. The assay involves use of a 96-well microtitre plate, designed for immunoassay, as the support for a purified, high-titre antiserum, raised against estradiol-6(O)-carboxymethyloxime linked to bovine serum albumin, and using horseradish peroxidase-labelled estradiol-6-(O)-carboxymethyloxime as the labelled species, with 2,2'-azino-bis-(3-ethylbenzthiazoline sulfonic acid) diammonium salt (ABTS) as the chromogenic substrate. The assay characteristics rival those of radio- or chemiluminescence immunoassays for estradiol.

Photoperiod entrainment of testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin cycles in rams in relation to testis size and semen quality.

Adult rams were exposed to photoperiod treatments over 2 years to study the influence of light regimes on pituitary-testicular activity and semen quality. Initially, all rams (12 per group) were exposed to 3 months of long days (16L:8D). Group 1 was then exposed to a regime of continuous short days (8L:16D) and Groups 2, 3, and 4 were exposed to 4 months of short days alternated with 1, 2, or 4 months, respectively, of long days.

The effect of thawing velocity on survival and acrosomal integrity of ram spermatozoa frozen at optimal and suboptimal rates in straws.

The effect of various thawing velocities on the motility and acrosomal maintenance of ram spermatozoa frozen at 20 degrees C/min (optimal) or 2 degrees C/min (suboptimal) was studied. The freeze-thaw motility and the percentage of intact acrosomes of spermatozoa frozen at 20 degrees C/min increased progressively with the thawing velocity. In semen frozen at 2 degrees C/min, motility of spermatozoa and the percentage of intact acrosomes declined drastically when the thawing velocity obtained in air at 20 degrees C was increased by thawing in water at 20 degrees C.

Use of enzyme-linked immunosorbent assay for measurement of bovine serum and milk progesterone without extraction.

An enzyme immunoassay for progesterone, using horseradish peroxidase as the label, was adapted for direct measurement of progesterone in serum or milk. Values obtained by direct measurement are highly correlated with values measured in extracts and are usable for convenient, rapid, accurate monitoring of the reproductive status of dairy cows. The assay is sensitive (ca.

A simple enzyme-linked immunosorbent assay for testosterone.

A new, enzyme-linked, immunosorbent assay for testosterone is described. The assay uses horseradish peroxidase coupled to testosterone as the tracer and offers the same sensitivity and reliability but greater convenience than radioimmunoassay. The assay is also simpler and more rapidly completed than previously described assays for testosterone.

Differential production of steroids by dispersed granulosa and theca interna cells from developing preovulatory follicles of pigs.

Dispersed granulosa and theca interna cells were recovered from follicles of prepubertal gilts at 36, 72 and 108 h after treatment with 750 i.u. PMSG, followed 72 h later with 500 i.

Prostaglandin production by dispersed granulosa and theca interna cells from porcine preovulatory follicles.

Prepubertal gilts were treated with 750 IU pregnant mares' serum gonadotropin (PMSG) and 72 h later with 500 IU human chorionic gonadotropin (hCG) to induce follicular growth and ovulation. Dispersed granulosa (GC) and theca interna (TIC) cells were prepared by microdissection and enzymatic digestion from follicles obtained 36, 72 and 108 h after PMSG treatment and incubated for up to 6 h in a chemically defined medium in the presence or absence of arachidonic acid, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and indomethacin. Production of prostaglandin E2 (PGE) and prostaglandin F2 alpha (PGF) was measured by radioimmunoassay.

Improved diagnostic accuracy by repetitive ultrasonic pregnancy testing in sheep.

Operator effects and instrument accuracy in using the Scanopreg ultrasonic pregnancy detector in sheep bred at synchronized estrus were studied in three experiments. In the first study, four operators tested the same 101 ewes at 60 and 80 days after breeding. The only significant difference among the four operators was that one operator consistently underestimated pregnancy.

Enzymatic dissociation of ovarian and uterine tissues.

A method is described for the preparation of high yields of viable, dissociated cells from porcine theca interna and corpus luteum and from human and bovine endometrium. The tissues were dissociated by incubation at 37 degrees C in a mixture of 0.5% collagenase, 0.

Seasonal effects of PMSG and number of inseminations on fertility of progestogen-treated sheep.

The influence of pregnant mares' serum gonadotropin (PMSG) on reproductive performance of sheep bred by artificial insemination (AI) was studied in the anestrous and estrous seasons. Ewes were treated with progestogen-impregnated intravaginal sponges in June and October. One-half of the ewes in each trial received PMSG at sponge removal and were inseminated 55 h after sponge removal.

Influence of sperm number and seminal plasma on fertility of progestagen-treated sheep in confinement.

Progestagen-impregnated vaginal sponges + PMSG were used to synchronize oestrus in crossbred adult ewes which were inseminated 56 h after sponge removal with 0.5 ml diluted semen containing 400, 200, 100, 50 or 25 x 10(6) spermatozoa per insemination. The diluent was skim milk-citrate or pooled seminal plasma.

Influence of estradiol-17 beta on fertility in confined sheep inseminated with frozen semen.

Impaired sperm transport is believed to be a major cause of reduced fertiity in ewes inseminated with frozen semen. Because of suggestions that estradiol improves sperm transport, estradiol-17 beta was given to mature ewes at progestagen-induced estrus to test effects on fertility after artificial insemination with frozen semen. Conception rates, based on progesterone determinations made 18 days after insemination, were 43% for ewes injected with 50 microgram estradiol-17 beta and inseminated with frozen semsn, 52% for ewes inseminated with frozen semen but given no estradiol and 86% for ewes inseminated with fresh semen.

Metabolism of progesterone by chorionic cells of the early sheep conceptus in vitro.

Progesterone-4-14C was extensively metabolized during incubation with dispersed trophoblast prepared from chorionic membranes of the 21-day sheep conceptus. Of the metabolites formed, 17, 20 alpha-dihydroxypregn-4-en-3-one, 20 alpha-hydroxypregn-4-en-3-one, 20 beta-hydroxypregn-4-en-3-one, 5 alpha-pregnane-3 alpha, 17,20 alpha-triol, 5 beta-pregnane-3 alpha, 17,20 alpha-triol, 5 beta-pregnane-3 alpha,20 alpha-diol, 3 beta-hydroxy-5 alpha-pregnan-20-one, 3 alpha-hydroxy-5 beta-pregnan-20-one, 20 beta-hydroxy-5 beta-pregnan-3-one, 5 alpha-pregnane-3,20-dione and 5 beta-pregnane-3,20-dione were identified. These findings indicate that the sheep conceptus acquires extensive steroid metabolizing capability very early in pregnancy.