In Experiment 1, cleavage frequency and
in vitrodevelopment of domestic cat embryos produced
after in vitro maturation of oocytes obtained from
ovaries after ovariohysterectomy (in vivo) with that of
oocytes retrieved from follicle-stimulating hormone-treated donors at 24 h
after administration of luteinizing hormone (in vivo)
and fertilization by intracytoplasmic sperm injection (ICSI) or IVF were
compared. In each group presumptive zygotes were assessed for cleavage on IVC
Days 1 and 4 and for development to blastocysts on IVC Day 7.
In vitro matured oocytes had lower frequencies of
meiotic maturation (59.2% v. 66.5%), cleavage at Day 1
(41.4% v. 64.9%) and development to the
morula stage at Day 4 (65.8% v. 87.9%)
than did in vivo matured oocytes, after ICSI and IVF.
Development to the blastocyst stage was lower in
in vitro matured oocytes (19.0%) than
in vivo matured oocytes (29.5%) after ICSI. In
Experiment 2, we evaluated the capacity of sperm injected oocytes without a
visible polar body to undergo cleavage and in vitro
development. More in vivo matured than
in vitro matured oocytes underwent cleavage at Day 1
(46.6% v. 12.6%) and developed to the
morula stage by Day 4 (66.7% v. 46.1%),
but no blastocysts were obtained at Day 7 in either group. In Experiment 3, we
evaluated the in vivo viability of domestic cat embryos
derived from ICSI of in vitro matured oocytes. Morula
stage embryos were transferred to 18 domestic cat recipients either on Day 4
or 5 after oocyte recovery. A total of 3 domestic cat recipients were pregnant
after transfer to recipients on Day 5. Two pregnant cats delivered two normal
and healthy live male kittens on Day 68 of gestation and the remaining cat
delivered a male kitten on Day 62 that died during the last two days of
gestation. These results demonstrate that: (1)
inadequate cytoplasmic maturation of in vitro matured
domestic cat oocytes is the main cause of deficient oocyte activation;
(2) the injection of oocytes without a visible polar
body is a useful technique to evaluate oocyte cytoplasmic maturation; and
(3) blastocysts obtained after ICSI of
in vitro matured oocytes are viable and not a result of
parthenogenesis.
BackgroundIntracytoplasmic sperm injection (ICSI) is a component of infertility treatment often employed when conventional in vitro fertilization is unlikely to be successful. Despite good clinical results with ICSI, the procedure is typically associated with degeneration of a significant percentage (approximately 10%) of the treated oocytes. The cause of this degeneration remains unclear. Speculation that damage caused by oocyte compression during the injection procedure may be responsible has led to the development of a novel technique known as laser-assisted ICSI. This procedure involves drilling a small hole through the zona pellucida with a laser prior to sperm injection. Preliminary studies have suggested that laser-assisted ICSI may dramatically reduce oocyte degeneration rates. The objective of this study was to examine whether the reported benefits of laser-assisted ICSI could be verified on a larger, less-selected group of patients.MethodsOocytes retrieved from 59 patients scheduled for ICSI were randomly divided into equal treatment and control groups. Oocytes in the treatment group were inseminated by laser-assisted ICSI, while oocytes in the control group were inseminated by conventional ICSI. Outcome variables (oocyte fertilization and degeneration, embryo cell numbers and fragmentation on days 2 and 3, and compaction and blastocyst formation rates) were compared between treatment and control groups by paired-sample t-test. Subgroup analysis was performed according to zona pellucida and oolemma breakage patterns.ResultsNo significant differences between treatment and control groups were observed for any of the measured outcome variables. However, fragile zonae pellucidae were associated with significantly poorer embryo quality, and fragile oolemmas that broke easily upon insertion of the injection needle were associated with a significantly higher oocyte degeneration rate. Nevertheless, there were also no between-treatment differences in clinical outcomes within these patient subpopulations.ConclusionContrary to previous reports based on smaller sample sizes, the results of this study suggest that there is no benefit of laser-assisted ICSI, either for the general population of ICSI patients, or for patients prone to zona pellucida or oolemma fragility.
Purpose-Previously, diversion from the criminal justice system for people with learning disability (LD) and serious forensic needs in Scotland meant hospitalisation. More recently new legislation has meant that community-based rehabilitation is possible for this group. The purpose of this paper is to qualitatively explore the views of people with LD subject to these legal orders. This is both a chance to work in partnership to improve services and also to make the voices of this potentially vulnerable group heard. Design/methodology/approach-Semi-structured interviews were conducted with ten participants subject to a community-based order. All participants were male. Ages, index behaviour, and time spent on order varied. The data was transcribed and analysed using interpretative phenomenological analysis.
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