Search PubMed⌕ Search

Biomedical subjects

R H Foote

Publications and source records attributed to R H Foote.

300 records · Page 17Linked to original sources
PubMedDate not supplied

Reaction of fresh and frozen bull spermatozoa incubated with fresh and frozen bovine oviduct epithelial cells.

The hypothesis was tested that frozen bovine oviduct epithelial cells (BOEC) could provide a physiologic and standardized system for studying motility and acrosomal changes of fresh and frozen-thawed sperm. The BOEC were collected by lavage from cows and monolayers prepared from both fresh and frozen-thawed cells. Fresh and frozen semen processed from five bulls was extended in a modified Tyrode's medium and coincubated with both types of monolayers at 39 degrees C in 5% CO2 and 95% humidified air. After 5, 10 and 24 h of incubation, percentages of motile, progressively motile and acrosome-reacted unattached sperm were measured. The percentage of motile fresh sperm exceeded the motility of frozen sperm, and more fresh sperm attached to BOEC. More frozen sperm than fresh sperm were acrosome reacted. Fresh and frozen epithelial cells produced similar effects, except sperm motility was higher after 5 h of incubation with fresh BOEC. Thus, the convenient frozen-thawed coincubation protocol provides a practical in vitro system for studying capacitation and the acrosome reaction.

Acrosome↗
PubMedDate not supplied

Embryo survival, uterine fluids and tubal SEM in progesterone-asynchronized rabbits.

Survival of embryos exposed to several concentrations of uterine proteins and changes in tubal morphology in rabbits given low preovulatory doses of progesterone (P4) that had previously not affected ovulation or fertilization, but caused severe embryo mortality, were studied. In experiment 1, 332 morulae were cultured for 24 h in a control medium containing < 0.5 to > 3.0 mg x mL(-1) of Day 3 uterine fluid proteins. There was no difference in blastocyst development nor implantation to Day 12 following transfer of the blastocysts to recipients, except fewer implants developed in the BSA control. In experiment 2 the oviducts and uteri of control and P4-treated does were examined by SEM for 8 days following ovulation. Secretory cells in the oviducts and to a lesser extent in the uteri were stimulated by P4 treatment for 3 to 4 days after ovulation. Morphology of ciliated cells was unaffected. The subtle changes did not fully account for P4-induced embryo mortality in vivo.

Animals↗
PubMedDate not supplied

High catalase content of rabbit semen appears to be inherited.

Reactive oxygen species, as hydrogen peroxide, can be damaging to sperm. Most species have little protective catalase in their semen, but rabbit semen contains substantial amounts of catalase. The objective of the present study was to characterize a substantial number of Dutch rabbits for seminal content of catalase and determine whether differences were inherited. Usually, 4 or more semen samples were analyzed per male. Catalase was measured by a gasometric procedure. In Experiment 1, the correlation between duplicate determinations was r = .99, and between 2 sets of semen samples from 55 males it was r = .95. There was a significant difference (P < .05) among pairs of males from 6 litters. In Experiment 2, semen from each of 11 males collected at an interval of 1 year contained an average of 13 and 12 units of catalase per mL of semen in consecutive years. The correlation between pairs of samples was r = .85. This indicated that the condition was permanent, and possibly genetically controlled. Experiment 3 analyzed the catalase content of semen from 7 sires and 32 sons. The heritability of seminal catalase concentration was 0.48. These studies indicate that rabbit seminal plasma is high in catalase, and that a substantial portion of the differences among males are under genetic control.

Aging↗
PubMedDate not supplied

Accessory sperm as an indication of fertilizing ability of rabbit spermatozoa frozen in egg yolk-acetamide with detergent.

Many factors besides initial semen quality affect fertilization rates as sperm interact with the environment of the female reproductive tract. One of these factors is sperm transport, which can be evaluated by accessory sperm counts. Dutch rabbits were used to test the effects on sperm transport, fertilization, and production of young when sodium and triethanolamine lauryl sulfate (STLS) detergent was added to a medium for sperm cryopreservation. When STLS was added in 10 concentrations ranging from 0% to 2.0% (vol/vol) to an egg yolk-acetamide semen extender, optimal post-thaw motility of rabbit sperm occurred when 0.2% to 0.7% STLS was included. However, when 0%, 0.2%, and 0.7% STLS was included to cryopreserve sperm used for insemination, the fertilization rates were 95%, 68%, and 75%, and the corresponding mean numbers of accessory sperm per embryo were 13.1, 1.7, and 0.4 (P < .05). In another experiment, increasing the acetamide concentration from 0.75 M to 1.25 M decreased fertilization rates from 66% to 35%, and was associated with 4.5 and 0.6 accessory sperm per embryo (P < .05). In the final experiment, 48 does inseminated with sperm cryopreserved with 0%, 0.35%, and 0.70% STLS were allowed to produce young. Corresponding pregnancy rates were 56%, 56%, and 31% (P < .05), and litter sizes were 5.6, 4.1, and 4.2 (P > .05). In these studies, low concentrations of STLS improved motility of frozen-thawed sperm, but fertilization and pregnancy rates were reduced. Sperm transport was correspondingly reduced, and the accessory sperm count provided a reliable measure of the effect of STLS on fertility in contrast to the assessment of the percentage of motile sperm.

Acetamides↗
PubMedDate not supplied

A comparison of two computer-automated semen analysis instruments for the evaluation of sperm motion characteristics in the stallion.

Two commercially available computer-automate semen analysis instruments (CellSoft Automated Semen Analyzer and HTM-2000 Motion Analyzer) were compared for their ability to report similar results based on the analysis of pre-recorded video tapes of extended, motile stallion semen. The determinations of the percentage of motile cells by these instruments were more similar than the comparisons between subjective estimates and either instrument. However, mean values obtained from the same sample may still differ by as much as 30 percentage units between instruments. Instruments varied with regard to the determinations of mean sperm curvilinear velocity and sperm concentration, but mean sperm linearity determinations were similar between the instruments. We concluded that the determinations of sperm motion characteristics by subjective estimation, CellSoft Automated Semen Analyzer, and HTM-2000 Motility Analyzer are often dissimilar, making direct comparisons of results difficult.

Animals↗
PubMedDate not supplied

Relationship of semen quality, number of sperm inseminated, and fertility in rabbits.

The relationship between the total number of sperm inseminated, semen quality, and fertility in rabbits was investigated, using fractionated or unfractionated semen and different diluting fluids. Semen was from Dutch-belted males collected twice weekly with an artificial vagina. All does were superovulated except in Experiment 3. In Experiment 1, sperm were fractionated on discontinuous 4% and 10% bovine serum albumin columns. Sperm from each portion of the gradient, along with unfractionated controls, were diluted to give 0.25 x 10(6), 0.5 x 10(6), 1.0 x 10(6), and 2.0 x 10(6) total sperm per insemination. In Experiment 2, sperm were diluted with Dulbecco's phosphate-buffered saline to provide 0.10 x 10(6), 0.50 x 10(6), and 1.0 x 10(6) total sperm per insemination, with minimal processing time. In Experiment 3, does were allowed to kindle after inseminating 0.1 x 10(6) or 1.0 x 10(6) sperm. In Experiment 4, sperm were diluted with TALP buffer: seminal plasma 1:1 to 0.025 x 10(6), 0.05 x 10(6), and 0.10 x 10(6) total sperm per insemination. Over 2,800 embryos or unfertilized oocytes were obtained either 24 or 48 hours after insemination to measure fertility. Sperm numbers required for normal fertility were 0.50 x 10(6) in Experiment 1 and only 0.05 x 10(6) in Experiment 4. This reduction presumably was due primarily to reduced processing time and diluent change. Litter size was normal with 0.1 x 10(6) sperm (Experiment 3). In Experiment 4, computer-assisted sperm analysis (HTM 2030 system; Beverly, Massachusetts) was adapted to successfully screen out some of the "interfering" granules in rabbit semen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Media and dilution procedures tested to minimize handling effects on human, rabbit, and bull sperm for computer-assisted sperm analysis (CASA).

Proper handling of semen prior to computer-assisted sperm analysis (CASA) is critical if the analysis is to be representative of the fresh sample. The effects of diluting medium or dilution and holding time before CASA on multiple sperm characteristics were studied. Four replicates of unselected semen samples from each of eight human donors were diluted with phosphate-buffered saline (PBS)-glucose plus bovine serum albumin (BSA), with Tyrode's albumen lactate pyruvate (TALP), and with high-potassium TALP (K-TALP) to a concentration of approximately 25 x 10(6) sperm/ml. The diluted semen was held for 0, 1, and 2 hours at approximately 30 degrees C before CASA, with little difference between the three diluents in all 12 variables measured. There was a decline of 3-6% in the proportion of motile sperm over a 2-hour period (P < 0.05). Donors were the largest source of differences (P < 0.05). Rabbit sperm (five bucks, four ejaculates per buck) were processed in a manner similar to that of the human sperm. There was a major effect of media. The average percentages of motile sperm over 2 hours in TALP, K-TALP, and PBS were 76, 42, and 29%, respectively (P < 0.05), with a decline of only 3% in TALP during the 2 hours. Hyperactivity and other characteristics were affected by treatment. Donors were a large source of variation. Bull semen (10 bulls, two ejaculates per bull) either was not diluted or diluted with TALP 2x or 4x and held for 0, 1, and 2 hours at 30 degrees C. It was then diluted to 25 x 10(6) sperm/ml with TALP. There was little change in most sperm characteristics in any treatment during the first hour, although many of the changes were statistically significant. The percentage of motile sperm in undiluted semen declined from 87% to 82% over 2 hours. Modified TALP was a suitable medium for sperm from all three species, and a simple PBS-glucose-BSA medium can be used for human sperm.

Animals↗
PubMedDate not supplied

Computerized imaging and scanning electron microscope (SEM) analysis of co-cultured fresh and frozen bovine sperm.

Fresh and frozen-thawed bull sperm were incubated with bovine oviductal epithelial cells and segments from the oviducts to examine the usefulness of these culture systems to model sperm changes in vivo. Changes in sperm motion characteristics [computer-assisted sperm analysis (CASA)] and surface morphology [scanning electron microscopy (SEM)] were evaluated. In Experiment 1, fresh and frozen sperm were suspended in the Brackett and Oliphant medium or modified Tyrodes medium (mTALP) and incubated for 0, 3, 6, and 9 hours in direct contact with bovine oviductal-epithelial cell (BOEC) monolayers prepared from oviducts of cows in the periovulatory phase of estrus. The percentage of motile sperm decreased gradually in mTALP, but decreased rapidly in Brackett's defined medium after 3 hours of incubation, with overall averages of 55 and 32%, respectively. The percentage of motile fresh sperm exceeded frozen-thawed sperm under all conditions. In Experiment 2, sperm suspended with mTALP were incubated in dishes without monolayers (control), with monolayers, and within the segments of the oviduct for 0, 3, and 6 hours. In the epithelial cell monolayers, the percentage of motile sperm was similar to the controls throughout incubation, but after 3 hours in the oviductal segments, a decrease, partly associated with more rapid rupture of acrosomal membranes occurred. Sperm velocity was higher (100 microns/second) in fresh sperm than in frozen sperm (85 microns/second). Acrosomal changes, discernible with SEM after 3 hours of incubation, increased with time and were always found more often in frozen than in fresh sperm. The BOEC-monolayer system provided a useful in vitro model to study pre-fertilization changes in sperm.

Acrosome↗
PubMedDate not supplied

Effect of repeated testicular biopsy on testis function and semen quality in dogs.

The study was designed to quantitatively evaluate the effect of repeated testicular biopsy of avascular areas by the open method on spermatogenesis, semen quality, and sperm output in dogs. After a 5-week standardization period of semen collections 3x per week, 10 sexually mature Beagle dogs were divided into two groups, approximately equalized based on previous sperm output. Semen collections were continued for 20 weeks. One group was controls without treatment until unilaterally orchidectomized after weeks 16 and 20; a second group had one testis biopsied on weeks 1, 5, and 9 and removed after week 16, with the second testis removed after week 20. Sperm output per week during the summer declined in the control group from 851 x 10(6) to 725 x 10(6) (15%). The decline in the biopsied control group collected simultaneously was 22%, presumably reflecting a seasonal effect plus a possible small treatment effect. At 16 weeks, the testes removed from the controls averaged 7.1 g and the testes biopsied three times in the second group averaged 6.4 g (P > 0.05). Scrotal-testicular measurements taken in live animals were correlated with testicular weights at orchidectomy (r = 0.81). An average of 36.7 mg of tissue was removed at each biopsy, sufficient to evaluate 100 to >200 seminiferous tubules in cross-section. Sperm motility and frequency of all stages of the cycle of the seminiferous epithelium were similar between control and biopsied dogs. It is concluded that repeated testicular biopsy of avascular areas can provide sufficient tissue for histopathologic evaluation without significant interference with spermatogenesis.

Animals↗
PubMedDate not supplied

Use of Hoechst 33342 stain to evaluate live fresh and frozen bull sperm by computer-assisted analysis.

The objective of this research was to investigate possible procedures for evaluating living bull sperm stained with Hoechst 33342 while in a simple medium and in commonly used complex egg yolk-glycerol-Tris (EYGT) and whole milk-glycerol (WMG) extenders. The two semen extenders provide good cryoprotection, but the latter one virtually obscures the sperm. To evaluate sperm motion characteristics when static nonsperm particles are present, a new Hamilton Thorne epifluorescent optical system (UV) with a strobe light was developed for potential use with DNA-stained sperm. This system permitted examination for the first time of sperm motion characteristics in milk. In Experiment 1 (four bull semen replicates with five dye concentrations and three incubation times), 2.5 microg/ml of Hoechst 33342 stained live and dead sperm sufficiently in a modified Tyrode's solution to measure all sperm characteristics without depressing motility, which was validated by using phase-contrast to analyze stained and unstained controls. In Experiments 2a and 2b, each using semen from four bulls with a 5 x 5 factorial arrangement, it was determined that 40 to 60 microg/ml of dye in EYGT or WMG, with UV illumination for 20 minutes, was optimal. There was no detrimental effect on sperm motility. In Experiment 3, analyses of two ejaculates, from each of eight bulls, confirmed that motion characteristics of sperm in EYGT and WMG were not depressed when the sperm were stained with Hoechst 33342. These experiments demonstrate that the dye concentrations and exposure times developed for use with the new epifluorescent optics facilitate evaluating bull sperm frozen in particle-filled whole milk and should be useful for sperm evaluation of a variety of species when nonsperm particulate matter may otherwise interfere.

Animals↗