Role of reproductive technologies and genetic resource banks in animal conservation.
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In combination with modem reproductive technologies, there is potential to use frozen and stored germplasm (genetic resource banks) to support conservation measures for the maintenance of genetic diversity in threatened species. However, turning this idea into reality is a complex process, requiring interdisciplinary collaboration and clearly defined goals. As the number of species deserving the attention of conservation scientists is overwhelmingly large, yet detailed knowledge of reproductive physiology is restricted to relatively few of them, choosing which species to conserve is one of the most difficult issues to be tackled. Besides the direct application of technologically advanced reproductive procedures, modern approaches to non-invasive endocrine monitoring play an important role in optimizing the success of natural breeding programmes. Through the analysis of urine and faecal samples, this type of technology provides invaluable management information about the reproductive status of diverse species. For example, it is possible to diagnose pregnancy and monitor oestrous cycles in elephants and rhinos without causing stress through restraint for sample collection. In this review, we identify the potential contribution of reproductive biology and genetic resource banks to animal conservation, but also highlight the complexity of issues determining the extent to which this potential can be achieved. (+info)
The effects of cryopreservation on semen from men with sarcoma or carcinoma.
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PURPOSE: This study evaluated prefreeze and postthaw semen quality before treatment in patients with different types of sarcomas and carcinomas to determine whether cryopreservation would be of value for these patients. METHODS: Semen specimens were obtained from 50 normal donors and from 21 patients with carcinoma and from 14 patients with sarcoma. The specimens were cryopreserved by a standard freezing procedure using TEST-Yolk buffer. Prefreeze and postthaw sperm motion characteristics were measured. RESULTS: Prefreeze total motile sperm count was significantly higher in donors (median: 129.6 x 10(6)/ml) than in men with carcinoma (46.9 x 10(6)/ml, P < .001) or sarcoma (66.3 10(6)/ml, P = .04). The percent motility and percent linearity were significantly lower in patients with carcinoma. In postthaw specimens, total motile sperm count, curvilinear velocity, and linearity were significantly lower in patients with carcinoma. CONCLUSIONS: The two patient groups in this study had poor semen quality when compared with healthy donors both before and after cryopreservation. Sarcoma patients had better semen quality than carcinoma patients. As cancer therapy in these men could significantly impair their reproductive potential, these men should be advised to preserve their semen before starting treatment. (+info)
Oocyte and semen donation: a survey of UK licensed centres.
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In view of the difficulties encountered by licensed clinics in the recruitment of oocyte and semen donors, the present survey was commissioned by the National Gamete Donation Trust (NGDT) to provide systematic information on current practice as a basis for planning future recruitment strategies. Sixty-four clinics agreed to participate in the survey, of which 55 recruited oocyte donors, 30 recruited semen donors, and 24 recruited both oocyte and semen donors. Almost all of the clinics had experienced difficulty in obtaining a sufficient supply of donated oocytes, and many patients requiring treatment with donated oocytes were placed on a waiting list for more than one year. Three-quarters of potential donors changed their mind about donating after receiving information on the procedures involved. The difficulties in recruiting semen donors were generally less acute. In this case, the greatest problem was the high proportion of potential semen donors who were deemed unsuitable after completing the screening process. Clinics also reported a shortage of both oocyte and semen donors from specific ethnic groups. (+info)
Is a review of standard procedures for cryopreservation needed?: safe and effective cryopreservation-should sperm banks and fertility centres move toward storage in nitrogen vapour?
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A recent consultation documentation by the Human Fertilisation and Embryology Authority (HFEA) which focused on the safe cryopreservation of gametes and embryos highlighted the need for a review of the way that fertility clinics in the UK store potentially infective material. The main points for consideration were to: (i) ensure containers used for cryopreservation are guaranteed by manufacturers to withstand low temperatures; (ii) use secondary containers, i.e. 'double bagging' of samples if stored in the liquid phase; and (iii) store in nitrogen vapour as a 'safer' alternative. In this article we examine a number of issues related to vapour storage which need careful consideration, including safety, cost and the effectiveness of various storage techniques in maintaining gamete and embryo viability. We also discuss the effectiveness of vapour storage in comparison with current liquid nitrogen storage techniques. In conclusion, we propose that fertility clinics should be compelled to review their cryopreservation procedures, not just because of new legislation or indeed fear of litigation but by a moral obligation. (+info)
Gaining consent to freeze spermatozoa from adolescents with cancer: legal, ethical and practical aspects.
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Sperm banking for early adolescent cancer patients requires delicate, sensitive handling and, in the UK, consideration is required of statutory elements. No information at present exists about how adolescents with cancer are normally treated or counselled for sperm banking. Here we highlight the type of issues in relation to fertility preservation faced by clinicians and those faced by adolescents at a sperm storage laboratory. We explore the very real difficulties of bringing together these medical fields of assisted reproduction, oncology and the various pieces of legislation and focus specifically on gaining consent. Attention is paid to counselling and communication to help the patient reach an effective and informed decision to store spermatozoa. The role of parents in contributing towards communication and support, together with the legal constraints in decision making, is acknowledged. How absolute and fully 'informed' consent should be will always remain a contentious issue amongst the various specialists and disciplines. In relation to sperm storage, as a minimum the patients should understand the process that they are undertaking so that it is undertaken freely and without pressure. The practical approach to gaining consent that we are using seems a logical and practical method to help early adolescent patients to store spermatozoa. (+info)
Knowledge and experience regarding cancer, infertility, and sperm banking in younger male survivors.
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PURPOSE: The goal of this study was to survey male patients aged 14 to 40 years at diagnosis and recently treated in two cancer centers to determine their knowledge, attitudes, and experiences regarding cancer-related infertility and sperm banking. PATIENTS AND METHODS: A postal survey about cancer-related infertility and sperm banking was offered to 904 men diagnosed with cancer within the previous 2 years. Eight percent opted out of the study. The others were sent the survey, with a cover letter stating elements of informed consent. RESULTS: Although the return rate was only 27%, yielding a sample of 201 men, responders did not differ significantly from nonresponders by institution, age, ethnicity, or cancer site. Overall, 51% of men wanted children in the future, including 77% of men who were childless at cancer diagnosis. Despite some anxieties about their own survival and risks to their children's health, men felt that the experience of cancer increased the value they placed on family closeness and would make them better parents. Only 60% of men recalled being informed about infertility as a side effect of cancer treatment, and just 51% had been offered sperm banking. Those who discussed infertility with their physicians had higher knowledge about cancer-related infertility and were significantly more likely to bank sperm. Only 24% of men banked sperm, including 37% of childless men. Lack of information was the most common reason for failing to bank sperm (25%). CONCLUSION: All men who are about to receive cancer treatment that could impair fertility should be counseled about such side effects and given adequate information to make an informed decision about banking sperm. (+info)
Oncologists' attitudes and practices regarding banking sperm before cancer treatment.
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PURPOSE: The goal of this study was to survey oncologists in three different practice settings to determine their knowledge, attitudes, and practices regarding referring patients to bank sperm before cancer treatment. METHODS: A postal survey about knowledge, attitudes, and practices regarding banking sperm before cancer treatment was sent to 718 oncology staff physicians and fellows at two cancer centers and at sites in a Community Clinical Oncology Program. RESULTS: The return rate was 24% and did not differ by institution, oncologic specialty, or sex. Fellows were significantly more likely to participate (37%) than staff physicians (20%). Ninety-one percent of respondents agreed that sperm banking should be offered to all men at risk of infertility as a result of cancer treatment, but 48% either never bring up the topic or mention it to less than a quarter of eligible men. Neither greater knowledge about sperm banking nor seeing large numbers of eligible men yearly increased the likelihood of discussing the option. Barriers cited included lack of time for the discussion, perceived high cost, and lack of convenient facilities. Oncologists reported they would be less likely to offer sperm banking to men who were homosexual, HIV-positive, had a poor prognosis, or had aggressive tumors. Oncologists overestimated the costs of sperm banking and the number of samples needed to make cryopreservation worthwhile. CONCLUSION: Sperm banking should be offered as an option to all men at risk of infertility because of their cancer treatment. Clearer practice standards could help oncologists increase their knowledge about sperm banking and avoid dependence on biased patient selection criteria. (+info)
Sperm banking and rate of assisted reproduction treatment: insights from a 15-year cryopreservation program for male cancer patients.
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BACKGROUND: Semen cryostorage remains the only proven method to preserve fertility in men with cancer. However, the necessity and the justification of banking spermatozoa have been questioned because it has been reported that only a small percentage of patients are referred for assisted reproductive technologies using frozen semen. METHODS: A 15-year cryopreservation program involving 776 men with malignant diseases who were referred to the study institution for semen cryopreservation before proceeding with chemotherapy and/or radiotherapy was reviewed. Data regarding cancer diagnosis, age, semen quality, and use of frozen semen were analyzed. RESULTS: Sperm banking was not performed for 90 of the 776 subjects (11.6%) because of azoospermia. Sperm quality was reduced in men with testicular carcinoma. To date, 36 of the 686 patients who had banked spermatozoa (5.2%) have attended the clinic for assisted conception treatments using frozen spermatozoa. Cumulative rates related to the use of frozen semen at 4, 8, and 12 years were 4.5%, 8.7%, and 11.8%, respectively. Relevant factors demonstrated to be significantly associated with a lower probability of using frozen material were a younger age at the time of cryostorage and a diagnosis of testicular carcinoma. CONCLUSIONS: The rate of referral for assisted reproductive techniques in patients who have banked their semen is low but tends to rapidly increase extending the length of follow-up. The cumulative percentage of use is at least above 10% but a longer follow-up is required to draw definitive conclusions. A diagnosis of testicular carcinoma is associated with a lower rate of use when compared with other cancers. Cancer 2003;97:1624-9. (+info)