A possible explanation for the low incidence of gonosomal aneuploidy among the offspring of triplo-X individuals

A review of the reproductive performance of 47,XXX individuals showed that the incidence of gonosomal aneuploidy among the offspring is low. To explain this unexpected phenomenon it is hypothesized that fertile triplo-X individuals have chromosomally normal oogonia due to mitotic nondisjunction in a cell from which the primordial germ line took origin. Mosaic 46,XX/47,XXX individuals have a somewhat higher risk of bearing aneuploid offspring, possibly due to a constitutional tendency toward gonosomal nondisjunction.     

Fertility and outcomes of pregnancy after chemotherapy in a sample of childbearing aged women

The aim of the study was to review the characteristics and outcomes of pregnancies occurring in women of childbearing age after chemotherapy for malignant disease. Between November 1998 and October 1999, a total of 16 patients who were treated for ovary (three), mole (one), vaginal (one), breast (four), Hodgkin's disease (four), lung (one), melanoma (one) and osteosarcoma (one) carcinoma were identified and retrospectively questioned about their fertility status. All the 16 women included in this study received at least one alkylating agent. Five patients (31%) experienced anomalies of hormonal cycle during and after the treatment. All of them recovered normal cycle without consequence of fertility. Caesarean section was performed in seven of 20 (35%) pregnancies with known outcomes. No obstetrical events were reported. The 16 women had 21 pregnancies resulting in 18 normal infants, one newborn with a minor abnormality (tallus foot), one spontaneous abortion and one lost of follow-up to 6 months of pregnancy. The present survey suggests that cytotoxic drug exposure had no deleterious effects on subsequent pregnancies. A prospective and systemic survey would be the only means able to clarify the actual cancer therapy on reproductive outcome and to investigate the long-term effects in the progeny.     

No reason for a reduction in the number of offspring per sperm donor because of possible transmission of autosomal dominant diseases

A limit of 25 offspring per sperm donor has been imposed in The Netherlands since 1992, in order to prevent children from donors having a greater risk of consanguineous relationships than would occur in random individuals. An incident with a donor who developed a serious hereditary brain disease raised the question whether the limit of 25 should be reduced. Here I consider this suggestion from a genetic, psychological and legal standpoint. There appears to be no valid population genetics argument for limiting the number of donor offspring to below the figure that would prevent an increased chance of inbreeding. Reduction of the number of children per donor theoretically only results in transmission of greater diversity to donor offspring. Moreover, as within the general population, the total number of children conceived from sperm donors is negligible, the impact of donor offspring on the population genetics is anyhow insignificant. From a psychological standpoint, it should be noted that individuals making use of a donor, or their offspring, have no knowledge of other offspring conceived with their particular donor. This implies that the number of offspring per donor is of no relevance to them (provided of course there is an acceptably low chance of inbreeding). The new Dutch law on disclosure of donor identity to donor-insemination children, also produces no compelling reasons for a general reduction in the number of offspring per donor. Reduction desired by individual donors can be obtained by means of mutual agreements between sperm banks and donors. In conclusion neither the possible transmission of late-onset autosomal dominant diseases, nor other considerations necessitate a reduction in the offspring limit calculated to prevent increased risks of inbreeding among donor offspring.     

Incidence trends and familial risks in invasive and in situ cutaneous melanoma by sun-exposed body sites

We studied incidence trends, age-incidence relationships and familial risks in invasive and in situ cutaneous melanoma, based on the Swedish Family-Cancer Database of more than 10 million individuals. Offspring were 0-66 years of age. Cancers were obtained from the Swedish Cancer Registry from years 1961-98. The study was based on 9,771 offspring and 22,888 parents with invasive melanoma and 2,446 offspring and 5,017 parents with in situ melanoma. Incidence rates increased markedly for invasive melanoma in the trunk. For in situ melanoma, trunk and head and neck were affected, and, in addition, legs for women. The maximal incidence was around age 80 years, independent of the type or site in men; in women early onset superficially spreading melanoma shifted the age for maximal incidence to about 60 years. For in situ melanoma, lentigo maligna was the main histogenetic type in the head and neck but in the trunk and legs superficially spreading melanoma was somewhat more common. Standardized incidence ratios (SIR) were calculated for familial risk at exposed and covered sites. The combined familial risks for invasive and in situ melanoma were higher at covered (SIR 3.56 from parents) than sun-exposed (1.92 from parents) sites and they agreed when familiality was defined between parents and offspring or between siblings; the sibling SIRs were 3.90 at covered and 2.53 at exposed sites. The data suggest that the higher melanoma density at exposed sites masks familial effects. Furthermore, sun exposure does not appear to reinforce the familial effect.     

Social rearing conditions before weaning influence numbers and proportions of blood immune cells in laboratory rats

The influence of the early social rearing environment on blood cellular immunity was investigated in the male offspring of Long-Evans rats. Sons of females housed in pair groups (P-males) and sons of females living in a mixed sex colony (C-males) were studied. After weaning at the age of 21 days, offspring were housed individually to ensure identical experiences until the age of 100 days when immunological assessments were conducted. C-males had significantly higher numbers of blood CD4 and CD8 T cells as well as higher numbers of granulocytes and monocytes than P-males. In contrast, the number of B cells and NK cells was similar in P- and C-males. T-cell responsiveness to ConA, determined in the peripheral blood mononuclear cells and whole blood assays, did not differ significantly between the two groups. The study indicates that the early social environment affects numbers and proportions of many blood immune cell subsets in later life.     

An attempt to reconstruct children's donor concept: a comparison between children's and lesbian parents' attitudes towards donor anonymity

BACKGROUND: This study investigated the donor concept of children who were born by means of donor insemination (DI), and their lesbian parents. METHODS: A total of 41 children aged between 7 and 17 years, and 45 parents, took part in the follow-up study. In-depth topic interviews were used to reconstruct how DI children and their mothers perceived the donor. Data were collected about the birth story, about children's conversations with their mothers concerning donor characteristics and about children's and parents' attitudes towards the status of the donor. RESULTS: 54% of these children preferred donor anonymity at this point in their life, whereas 46% wanted to know more about the donor. The majority of the latter group would have liked to know the donor's identity, with boys outnumbering girls. The remaining children of this group were content with non-identifying information. Children wanted to know more about the donors whereas the majority of the mothers preferred the donor to remain anonymous. CONCLUSIONS: Our results suggest that among DI children in general and among members of the same family, unit opinions differ on the status of the donor. A flexible system offering different types of donors seems to be necessary in order to meet the needs of each family.     

What does it mean to be a donor offspring? The identity experiences of adults conceived by donor insemination and the implications for counselling and therapy

In the absence of research with adult donor offspring, this study begins to bridge that gap by asking individuals about their experiences as donor offspring and considering the implications for psychotherapeutic and counselling practice. Sixteen participants (13 male, three female, age range 26-55 years) recruited through donor insemination support networks in the UK, USA, Canada and Australia, were sent semi-structured questionnaires by E-mail and post. Using identity process theory as a framework for understanding participants' accounts, the data were qualitatively analysed using interpretative phenomenological analysis. Participants consistently reported mistrust within the family, negative distinctiveness, lack of genetic continuity, frustration in being thwarted in the search for their biological fathers and a need to talk to a significant other (i.e. someone who would understand). These experiences could be postulated as being indicative of a struggle to assimilate, accommodate and evaluate information about their new identities as donor offspring. Psychotherapists and counsellors need to be aware of these identity issues if they are to meet the needs of donor offspring within therapeutic practice.     

Volume loading hypoalgesia in SHR, WKY and F1 offspring of a SHR × WKY cross

The effects of volume loading on a nociceptive reflex, arterial blood pressure and heart rate were studied in spontaneously hypertensive rats (SHRs), Wistar Kyoto normotensive rats (WKYs) and the F₁ offspring of a SHR × WKY cross. Volume loading resulted in significantly greater inhibition of the tail-flick reflex to painful radiant heat in SHRs compared to WKYs. The F₁ offspring of a SHR × WKY cross showed levels of hypoalgesia to volume loading that were intermediate to those of SHRs and WKYs. There were no differences between these strains in their hypotensive and bradycardic responses to volume loading. These findings are discussed in terms of cardiovascular-somatosensory interactions.     

Emotional relationship quality of adult children with ageing parents: on solidarity, conflict and ambivalence

Emotions towards a relationship partner provide relevant and specific information about relationship quality. Based on this assumption the present study was performed to identify different types of emotional relationship quality of middle-aged adult children with their ageing parents. This was done by cluster analytic procedures in a sample of 1,208 middle-aged adult children (482 men, 726 women). Using ratings of positive and negative emotions towards their mother and father as grouping variables, the same four-cluster solution emerged for both the child–mother relationship and the child–father relationship. Clusters were labelled as amicable, disharmonious, detached and ambivalent relationships. Results showed that especially amicable relationships clearly prevailed followed by ambivalent, detached and disharmonious relationships. Clusters differed significantly with respect to gender of adult child, willingness to support, expected parental support and overt conflicts. In a cross-classification of cluster membership regarding the child–mother relationship (four clusters) and the child–father relationship (four clusters), all possible 16 combinations were observed, with a considerable degree of divergence regarding the type of relationship quality within the same family. Results are discussed with respect to types of emotional relationship quality, within family differences and the intrafamilial regulation of relationship quality.