Heme oxygenase-1 genotype of the donor is associated with graft survival after liver transplantation.

Heme oxygenase-1 (HO-1) has been suggested as a cytoprotective gene during liver transplantation. Inducibility of HO-1 is modulated by a (GT)(n) polymorphism and a single nucleotide polymorphism (SNP) A(-413)T in the promoter. Both a short (GT)(n) allele and the A-allele have been associated with increased HO-1 promoter activity. In 308 liver transplantations, we assessed donor HO-1 genotype and correlated this with outcome variables. For (GT)(n) genotype, livers were divided into two classes: short alleles (<25 repeats; class S) and long alleles (> or =25 repeats; class L). In a subset, hepatic messenger ribonucleic acid (mRNA) expression was correlated with genotypes. Graft survival at 1 year was significantly better for A-allele genotype compared to TT-genotype (84% vs. 63%, p = 0.004). Graft loss due to primary dysfunction (PDF) occurred more frequently in TT-genotype compared to A-receivers (p = 0.03). Recipients of a liver with TT-genotype had significantly higher serum transaminases after transplantation and hepatic HO-1 mRNA levels were significantly lower compared to the A-allele livers (p = 0.03). No differences were found for any outcome variable between class S and LL-variant of the (GT)(n) polymorphism. Haplotype analysis confirmed dominance of the A(-413)T SNP over the (GT)(n) polymorphism. In conclusion, HO-1 genotype is associated with outcome after liver transplantation. These findings suggest that HO-1 mediates graft survival after liver transplantation.

In vitro maturation and fertilization of oocytes recovered from free-ranging Burchell's zebra (Equus burchelli) and Hartmann's zebra (Equus zebra hartmannae).

A noninvasive repeatable method to harvest oocytes for in vitro fertilization (IVF) could potentially be used to assist reproduction in endangered equid species. The objectives of this study were to evaluate a specific transvaginal ultrasound-guided oocyte recovery procedure for use in zebra mares and the general applicability of IVF procedures in zebra. Ovaries were collected from Burchell's zebra (Equus burchelli) and Hartmann's zebra (Equus zebra hartmannae) mares at routine culling for Expt. I. Of the 144 oocytes recovered from these ovaries, 70% were of excellent quality. No significant difference in oocyte quality was found between the two zebra species. Zona drilling was performed on in vitro-matured oocytes prior to IVF. Epididymal sperm from culled Burchell's zebra stallions were used for IVF. The sperm either were exposed to calcium ionophore or were not treated and served as a control. In vitro fertilized oocytes were then co-cultured with zebra granulosa cells (ZGC) or with bovine oviduct cells (BOC) for up to 8 days. Overall, a 38% cleavage rate was obtained with 16% of sperm-exposed oocytes developing to the morula or blastocyst stage. All of the embryos that developed to at least the morula stage were cultured on BOC; whereas, none of those cultured on ZGC reached the morula stage during the same interval. Cleavage rates of oocytes inseminated with ionophore-treated or with control sperm were not significantly different, suggesting that ionophore treatment of epididymal sperm for IVF in these zebra species may be redundant. In Expt. II, 10 transvaginal ultrasound-guided oocyte aspiration procedures on five captive Burchell's zebra mares recovered a total of 33 oocytes (6.6 oocytes/female) of which 94% were considered viable. This approach may be an attractive means of producing gametes for assisted reproduction in endangered species. Furthermore, results from this study indicate that IVF may become a means of producing offspring from zebra and other equid species in the future.

The applicability of the cumulative embryo score system for embryo selection and quality control in an in-vitro fertilization/embryo transfer programme.

The cumulative embryo score system involves three aspects of relevance in pregnancy achievement during in-vitro fertilization (IVF) and embryo transfer: cleavage rates, morphological qualities and the number of embryos transferred. The scores of 602 IVF/embryo transfer trials were calculated and analysed to determine the system's relationship to pregnancy rate, pregnancy outcome and the incidence of twin and triplet pregnancies. The system was also applied to cycles where endotoxins were either present in or absent from culture medium, in order to evaluate its validity in quality control analyses. Pregnancy rates were found to increase from 4%, with scores between 1 and 10, to 35% in the 41-50 group. The score of 20 was the criterion for separating patients into poor and good pregnancy prognosis groups (P = 0.00001). Biochemical abortions occurred more frequently with scores < 20 (P = 0.00978), but a similar relationship was not found in clinical abortion rates (P = 0.62206). Birth rates below and above a score of 20 (2.8 and 19.2%, respectively) differed significantly (P = 0.0005). The scores of twins overlapped extensively with those of singleton births, but those of all triplets were > 40. The system did not reflect a correlation between embryo quality and the presence of endotoxins in culture medium.

Multiple attempts at embryo transfer: effect on pregnancy outcome in an in vitro fertilization and embryo transfer program.

PURPOSE: This study derives from the observation that a correlation exists between failed first attempts (FFA) at embryo transfer caused by one or more embryos remaining in the catheter and reduced pregnancy rates (20.3 vs 3.0%). The aim of this study was to examine the relationship between failed first attempts at transfer and contamination of the transfer set; the related aspects of cervix dilatation and late embryo transfer were also investigated. RESULTS: The following observations were made. Retention of embryos in the transfer sets significantly reduced the pregnancy rate (P = 0.015); catheters contaminated with blood and cervical mucus indirectly contributed to this effect by increasing the incidence of failed first transfer attempts. Even though cervical dilatations, if indicated by uterus sounding, were done 2 days before embryo transfer, no pregnancies were effected in these 18 cases (P = 0.0001). Late transfers of embryos, due to delayed fertilization or slow cleavage rates, yielded a pregnancy rate of 10.5%. CONCLUSION: The approach of immediately retransferring retained embryos does not solve the problem of reduced pregnancy rates in FFA cases. It is suggested that ET should be repeated 1 day later in FFA cases in an attempt to improve pregnancy rates.