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Biomedical subjects

G D Ball

Publications and source records attributed to G D Ball.

At least 19 recordsLinked to original sources
PubMed1999

Weight relapsers, maintainers, and controls: metabolic and behavioural differences.

The present investigation was undertaken to describe selected factors associated with the maintenance of body weight in three groups of women: relapsers (regained weight after losing weight), maintainers (maintained weight loss), and controls (weight stable). The following physiological variables were also assessed: resting energy expenditure (REE), serum glucose, insulin, leptin, triiodothyronine (T3), and body composition. As well, participants completed the interviewer-administered Weight Maintenance Questionnaire (WMQ). Overall, relapsers were older and heavier than maintainers and controls. As well, BMI, sum-of-four skinfolds, waist and arm circumference, serum leptin, and insulin levels were significantly greater for relapsers than for maintainers and controls. There were no differences between maintainers and controls in any of the parameters measured. Although relapsers revealed a history of weight cycling, the weight loss strategies and exercise habits of maintainers and relapsers did not differ. The data suggest that the higher body mass and fat mass in relapsers may explain the physiological differences between relapsers and maintainers.

Adipose Tissue↗
PubMed1995

Continuation of a donor oocyte pregnancy in a functionally agonadal patient without early oestrogen support.

A 40 year old functionally agonadal patient was the recipient of fertilized donated oocytes. She accidentally discontinued all oestrogen support on the day preceding embryo transfer until it was reinstated 12 days later. However, a pregnancy was established and resulted in the birth of healthy normal twin infants. This case report suggests that minimal amounts, if any, of oestradiol are sufficient to maintain an early pregnancy, provided adequate amounts of progesterone are given. This is consistent with a recent study conducted in subhuman primates.

Adult↗
PubMed1994

Treatment options for infertile couples.

Fast-developing technologies in infertility treatment make it a prime subject for review. In this paper, we revisit some of the basic biology of the male and female reproductive systems and point out where these systems break down. We then discuss some of the many technical treatment options available for the infertile couple and indicate where and when these technologies are best applied.

Adult↗
PubMed1993

A successful assisted reproductive technology satellite program.

A satellite program was implemented to provide IVF to interested infertile couples living in a five-state area. Thirty-six gynecologists were established as satellite sites after appropriate screening and training. No attempt was made to interchange reference serum specimens between laboratories. Patients were seen at Mayo Clinic for an initial consultation and did not return until the ovulatory dose of hCG was administered. There was no difference in cancellation, clinical pregnancy, and delivery rates between satellite and central unit monitored patients. Satellite monitoring decreases patient inconvenience and time away from home and the workplace without compromising cycle outcome.

Delivery of Health Care↗
PubMed1993

A novel ovarian stimulation protocol for use with the assisted reproductive technologies.

OBJECTIVE: To determine whether a new ovarian stimulation protocol termed "minimal stimulation" provides pregnancy rates (PRs) comparable with those in a conventional full stimulation protocol for patients undergoing assisted reproductive technologies (ART). DESIGN: Prospective, nonrandomized study of patients in minimal stimulation or full stimulation, followed by standard IVF and zygote intrafallopian transfer or uterine-ET. SETTING: The ART program of the Mayo Clinic, Rochester, Minnesota. PATIENTS: Women (n = 120) 42 years of age or younger with serum day 3 FSH level < or = 15.0 mIU/mL (conversion factor to SI unit, 1.0), normal thyroid-stimulating hormone and PRL levels, normal endometrial cavity as observed on hysterosalpingogram, and partners with a normal semen analysis. INTERVENTIONS: Oral clomiphene citrate, hMG, oocyte retrieval, IVF-ET. MAIN OUTCOME MEASURES: Cancellations, implantation, pregnancy. RESULTS: The cancellation rate was not significantly higher in minimal stimulation (25.8%) than in full stimulation (14.1%). Minimal stimulation cycles yielded fewer oocytes per aspiration (3.4 +/- 1.6) than full stimulation (10.1 +/- 5.4). There was no difference in the implantation rates per ET (minimal stimulation, 16.4%; full stimulation, 13.3%) or overall clinical PRs per retrieval (minimal stimulation, 31%; full stimulation, 42%). CONCLUSIONS: Minimal stimulation for IVF is less expensive than full stimulation and minimizes monitoring and patient discomfort. In addition, it produces acceptable PRs and represents an attractive alternative to select patients undergoing ART.

Adult↗
PubMed1992

Characterization of human sperm antigens and antisperm antibodies in infertile patients.

OBJECTIVE: To identify which sperm antigens may elicit the production of functionally important antisperm antibodies. DESIGN: Immunoblot analysis was performed on 69 serum and 9 seminal plasma samples from infertile patients, using detergent extracts of pooled donor sperm as the antigen source. Serum and seminal plasma had been previously tested by an indirect immunobead binding test (IBT); 61 IBT-positive and 17 IBT-negative samples were included in the study. Proteins recognized by IBT-positive but not IBT-negative samples were most likely to be cell surface antigens, whereas proteins recognized by both IBT-positive and IBT-negative samples were probably intracellular. Antibodies directed toward surface antigens would be most likely to affect fertilization. Characterization of sperm surface proteins on both acrosome-intact and -reacted sperm used labeling of cell surface proteins with an N-hydroxysuccinimide ester of biotin, fractionation of sperm heads and tails, and lectin binding to determine glycosylation. RESULTS: Specific immunoreactivity (with respect to IBT results) was observed to 35K, 40 to 45K, 57K, 66K, and 88 to 90K MW proteins. Characterization studies identified an 88K MW glycosylated plasma membrane protein, a 66K MW inner acrosomal membrane protein, a 34K MW inner acrosomal membrane protein, and a 35K MW prominent tail protein. CONCLUSION: Immunological infertility may involve several antigens characterized in this study. Further studies are necessary to determine if antibodies to these specific proteins interfere with sperm function.

Acrosome↗
PubMed1988

Factors affecting the cryosurvival of mouse two-cell embryos.

A series of 4 experiments was conducted to examine factors affecting the survival of frozen-thawed 2-cell mouse embryos. Rapid addition of 1.5 M-DMSO (20 min equilibration at 25 degrees C) and immediate, rapid removal using 0.5 M-sucrose did not alter the frequency (mean +/- s.e.m.) of blastocyst development in vitro when compared to untreated controls (90.5 +/- 2.7% vs 95.3 +/- 2.8%). There was an interaction between the temperature at which slow cooling was terminated and thawing rate. Termination of slow cooling (-0.3 degrees C/min) at -40 degrees C with subsequent rapid thawing (approximately 1500 degrees C/min) resulted in a lower frequency of blastocyst development than did termination of slow cooling at -80 degrees C with subsequent slow thawing (+8 degrees C/min) (36.8 +/- 5.6% vs 63.9 +/- 5.7%). When slow cooling was terminated between -40 and -60 degrees C, higher survival rates were achieved with rapid thawing. When slow cooling was terminated below -60 degrees C, higher survival rates were obtained with slow thawing rates. In these comparisons absolute survival rates were highest among embryos cooled below -60 degrees C and thawed slowly. However, when slow cooling was terminated at -32 degrees C, with subsequent rapid warming, survival rates were not different from those obtained when embryos were cooled to -80 degrees C and thawed slowly (52.4 +/- 9.5%, 59.5 +/- 8.6%). These results suggest that optimal cryosurvival rates may be obtained from 2-cell mouse embryos by a rapid or slow thawing procedure, as has been found for mouse preimplantation embryos at later stages.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Cryopreservation of human spermatozoa. III. The effect of cryoprotectants on motility.

A series of experiments was conducted to examine potential toxic effects of cryoprotectants on motility of human spermatozoa. The data indicated that exposure of spermatozoa to cryoprotectant medium for as little as 15 minutes at room temperature caused a reduction in motility. This reduction in motility was caused by glycerol. Lowering glycerol concentrations from 7.5% to 5.0% improved sperm motility at 24 hours post-thaw. Sperm motility was not affected by either slow or abrupt cooling rates above -5 degrees C. Motility was greater in cryopreserved sperm at 24 hours post-thaw when glycerol was added at -5 degrees C rather than at room temperature. These data suggest that avoiding glycerol toxicity either by reducing the concentration used or by adding glycerol at a lower temperature, or both, may improve human sperm cryosurvival rates.

Cryoprotective Agents↗
PubMed1987

Cryopreservation of human spermatozoa. I. Effects of holding procedure and seeding on motility, fertilizability, and acrosome reaction.

Three experiments were conducted to evaluate effects of holding semen at +5.0 degrees C for 30 minutes or -5.0 degrees C for 10 minutes and ice crystal induction (seeding) on frozen-thawed human spermatozoa. In experiment 1, spermatozoa were frozen, and postthaw motility was evaluated immediately (0 hour) and 24 hours later. At both 0 and 24 hours, nonfrozen control samples had higher motility than all other treatment groups. At 0 hour postthaw, motility was higher in samples held at -5.0 degrees C for 10 minutes with no significant effect of seeding. At 24 hours, samples held at -5.0 degrees C for 10 minutes and seeded, but not samples held at -5.0 degrees C and not seeded, had higher motility than samples held at +5.0 degrees C. In experiment 2, semen samples were frozen, and fertilizability was evaluated in a zona-free hamster egg penetration assay. Seeded samples had a higher frequency of sperm penetration than either nonfrozen or nonseeded samples. In experiment 3, nonfrozen controls and frozen treatment groups were evaluated for the frequency of survival and acrosomal integrity. Seeded samples had higher frequencies of survival and loss of acrosomal integrity than nonseeded samples. All frozen-thawed samples had a lower frequency of survival and a higher frequency of loss of acrosomal integrity than nonfrozen controls. Although altered patterns of fertilizability and acrosomal integrity are induced, collectively these data suggest that incorporating a holding temperature of -5.0 degrees C for 10 minutes and seeding may result in a superior protocol for freezing human spermatozoa.

Acrosome↗
PubMed1987

Cryopreservation of human spermatozoa. II. Postthaw chronology of motility and of zona-free hamster ova penetration.

Postthaw dynamics of motility maintenance and ability to penetrate zona-free hamster ova were examined with human sperm. Ten semen samples were each divided into two equal volumes; one was cryopreserved while the other half remained untreated. Frozen samples were thawed, and initial evaluations for motility and hamster egg penetration were made on both untreated and frozen-thawed samples. The time difference between the initial evaluations for the two treatment groups was approximately 30 minutes as a result of the time required to freeze and thaw aliquots. Subsequent evaluations were made 6, 12, 24, and 48 hours later. Over all times both the motility and fertilizability of cryopreserved spermatozoa were significantly reduced (P less than 0.05) when compared with those of untreated sperm. The pattern of motility loss over time was similar between untreated and frozen-thawed sperm (P greater than 0.10). Conversely, differences between untreated and frozen-thawed sperm in fertilizability patterns were dramatic (P less than 0.05). This was evidenced by penetration rates for cryopreserved sperm highest at 0 hour and decreasing over time, whereas penetration by untreated spermatozoa was lowest at 0 hour, increasing to a maximum at 24 hours. These observations may be important in the development of laboratory protocols for freezing and clinical protocols for using frozen-thawed sperm.

Animals↗
PubMed1986

Cryopreservation of hamster oocytes: effects of vitrification or freezing on human sperm penetration of zona-free hamster oocytes.

Three experiments were conducted for evaluation of the efficacy of conventional freezing or vitrification of hamster oocytes for use in a human sperm penetration assay (hSPA). In experiment 1, oocytes were cryopreserved and evaluated for survival on the basis of morphologic criteria. Survival of vitrified oocytes and that of frozen oocytes were not different, whereas all cryopreserved groups had lower survival than noncryopreserved controls. In experiment 2, oocytes were conventionally frozen or vitrified and evaluated in an hSPA. Vitrified oocytes had a lower frequency of sperm penetration than frozen oocytes, and all cryopreserved groups had lower penetration rates than untreated controls. In experiment 3, oocytes were exposed to the cryoprotectant used to vitrify (VS1) or freeze (DMSO) but not cooled prior to evaluation in an hSPA. Exposure to DMSO but not VS1 reduced hSPA values. It is concluded from these experiments that while all cryopreserved oocytes do not survive, at current stages of development conventionally frozen oocytes perform better than vitrified oocytes in the hSPA and losses associated with conventional freezing procedures may be related to cryoprotectant exposure, whereas vitrification losses are more probably due to events associated with rapid cooling and/or warming of the oocytes.

Animals↗
PubMed1985

Effect of serum source on human fertilization and embryonic growth parameters in vitro.

A total of 100 mature oocytes from 13 consecutive patients were randomly assigned from each patient to one of two treatment groups (n = 53 for group 1, n = 47 for group 2). Group 1 oocytes were incubated throughout the culture periods in medium supplemented with 7.5% homologous patient serum. Group 2 oocytes were treated similarly, except the serum supplement was of fetal cord origin. End points for examination included fertilization frequency, normality of fertilization, stage of embryonic development at two time periods, and quality of embryonic development at two time periods. None of the end points examined revealed significant differences between patient serum and fetal cord serum.

Blastomeres↗