'I know it's not normal but it's normal to me, and that's all that matters': experiences of young adults conceived through egg donation, sperm donation, and surrogacy.

STUDY QUESTION: What are thoughts and feelings of young adults born following egg donation, sperm donation, and surrogacy? SUMMARY ANSWER: Young adults felt either unconcerned or positive about the method of their conception. WHAT IS KNOWN ALREADY: Much of what we know about adults born to heterosexual couples following anonymous donation has come from samples of donor conceived people who had found out about their origins during adulthood. There have been no studies of how young adults born through surrogacy feel about their conception and towards their surrogate. STUDY DESIGN, SIZE, DURATION: Thirty-five young adults were interviewed as part of the seventh phase of a larger multi-method, multi-informant longitudinal study of assisted conception families in the UK. Adults were conceived using either egg donation, sperm donation, gestational surrogacy, or genetic surrogacy and were raised in households headed by heterosexual couples. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants had a mean age of 20 years and were born following traditional surrogacy (n = 10), gestational surrogacy (n = 5), egg donation (n = 11), or sperm donation (n = 9). All young adults born following sperm donation and most (n = 10) born from egg donation had an anonymous donor. In all surrogacy arrangements, the parents had met the surrogate prior to treatment. The majority of young adults were told about their conception by the age of 4 years. Participants were interviewed over the internet using a semi-structured interview. Interviews were transcribed verbatim and analysed using qualitative content analysis to understand young adults' thoughts and experiences related to their conception and whether they were interested in meeting their donor or surrogate. MAIN RESULTS AND THE ROLE OF CHANCE: Fourteen (40%) young adults felt their conception made them feel special or unique, with the remainder feeling either neutral or unconcerned (n = 21, 60%). A higher proportion of young adults conceived using egg donation (n = 8, 73%) felt unique/special compared to young adults born following sperm donation and surrogacy. For 10 of the young adults, their feelings about their conception had changed over time, with most becoming more positive (n = 9, 26%). For most young adults (n = 22, 63%), conception was rarely or infrequently discussed with others. However, when it was, these conversations were largely conducted with ease. Most (n = 25, 71%) did not know other individuals born through the same method of conception as themselves, and the vast majority (n = 34, 97%) were not members of any support groups. For the 25 young adults not in contact with their donor or surrogate, 11 wished to meet them, 8 did not want to have contact, and 6 were unsure. Young adults in contact with their donor or surrogate had varying levels of closeness to them. Only one young adult had searched for the identity of their donor. LIMITATIONS, REASONS FOR CAUTION: Of the 47 young adults invited to participate in the present study, 35 agreed to take part resulting in a response rate of 74%. It is therefore not known how those who did not take part felt about their conception. Given that the families reported here had been taking part in this longitudinal study from when the target child was aged 1 year, they may have been more likely to discuss the child's conception than other families. The study also utilized self-report measures, which may have been prone to social desirability, with donor conceived young adults wanting to present their experiences in a positive light. WIDER IMPLICATIONS OF THE FINDINGS: The findings suggest that young adults born through surrogacy and donor conception do not feel negatively about their birth and this may be a consequence of the young age at which they found out about their conception. Although some young adults said they wished to meet their donor, this did not necessarily mean they were actively searching for them. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by the Wellcome Trust [grant number 208013/Z/17/Z]. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

'I'm the only mum she knows': parents' understanding of, and feelings about, identity-release egg donation.

STUDY QUESTION: How do parents understand and feel about identity-release egg donation? SUMMARY ANSWER: Almost one-third of mothers and fathers did not understand the identifiable nature of their egg donation; mothers expressed complex and sometimes difficult feelings about the prospect of future donor-child contact. WHAT IS KNOWN ALREADY: Identity-release egg donation has been the only treatment option available to patients wishing to pursue this route to parenthood in the UK since 2005. However, little is known about how well parents understand this legislation, and how they feel about potential donor-child contact. STUDY DESIGN, SIZE, DURATION: This qualitative interview study included 61 mothers and 51 fathers whose 5-year-old children were conceived via identity-release egg donation. Interviews were conducted between April 2018 and December 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data are reported from phase two of a longitudinal study of families created using open-identity egg donation. In-depth, semi-structured interviews were conducted with mothers and fathers. The interviews contained a section on what parents understood about the identifiable nature of the donor. These data were analysed using qualitative content analysis. Mothers who understood the identifiable nature of their egg donation (n = 44) were then asked about their thoughts and feelings regarding the prospect of future donor-child contact. Mothers' narratives were analysed using thematic analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Almost one-third of parents (28% of mothers, n = 17; 31% of fathers, n = 16) did not understand the identifiable nature of their egg donation. Mothers' and fathers' misunderstandings about identity-release egg donation fell into two categories: (i) Unclear about identity-release and (ii) Belief that the donor is anonymous. Reflexive thematic analysis revealed that egg donation mothers' feelings about identity-release donation could be understood via three organizing themes: (i) identity-release as a threat, (ii) acceptance: it is what it is and (iii) embracing identity-release. The findings indicated that egg donation mothers utilized various strategies to manage their feelings about identity-release egg donation in day-to-day life, and each theme was associated with at least one coping strategy. LIMITATIONS, REASONS FOR CAUTION: Participants were predominantly from White, middle-class backgrounds. Further research with a more diverse sample is needed to improve generalizability. WIDER IMPLICATIONS OF THE FINDINGS: These findings indicate that parents would benefit from more comprehensive provision of information, both at time of treatment and following conception, to ensure they have fully understood the nature of the donation. Parents may also benefit from follow-up care to help manage any complex or difficult feelings about donor-child contact. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by a Wellcome Trust Collaborative Award [208013/Z/17/Z]. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Parent-child relationship quality and child psychological adjustment in families created using egg donation: children's perspectives at age 5 years.

STUDY QUESTION: What are children's perspectives of the quality of their relationships with their parents and their own psychological well-being in families created using egg donation? SUMMARY ANSWER: Children's scores indicated good parent-child relationship quality and high levels of psychological well-being, with children in families created using egg donation rating their relationships with their mothers as higher in warmth/enjoyment than children in a comparison group of families created using IVF. WHAT IS KNOWN ALREADY: Little is known about how children in families created through egg donation view their family relationships and their own psychological well-being. Research with 7-and-10-year-olds in anonymous egg donation families has indicated good parent-child relationship quality from children's perspectives, but studies have not involved younger children or those conceived following identity-release egg donation. STUDY DESIGN, SIZE, DURATION: This study included 50 children who had been born through egg donation and a comparison group of 43 children conceived through IVF with the parents' own gametes. Data were collected between April 2018 and December 2019. The sample forms part of a larger longitudinal study examining family functioning in families created through fertility treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS: Children were aged 5 years old and had been born into families with different-sex couple parents. All families were visited at home. Children were administered the Berkeley Puppet Interview, a standardized assessment of parent-child relationship quality and psychological well-being. MAIN RESULTS AND THE ROLE OF CHANCE: Children in egg donation families rated their relationships with their mothers as higher in warmth and enjoyment than did children in IVF families. No differences were found between the two family types in children's ratings of the father-child relationship, or in children's ratings of their own psychological well-being. LIMITATIONS, REASONS FOR CAUTION: It is possible that children who did not consent to take part in the research had less positive perceptions of their family and themselves than children who participated. WIDER IMPLICATIONS OF THE FINDINGS: The findings are relevant to UK clinics offering identity-release egg donation, to parents who have used egg donation to create their family and to individuals and couples considering their fertility treatment options. That children in egg donation families were more similar than different to children in IVF families in their self-concept and perception of their family relationships should prove reassuring. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by a Wellcome Trust Collaborative Award [208013/Z/17]. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Psychological well-being of identity-release egg donation parents with infants.

STUDY QUESTION: What are the psychological health, relationship quality and perceived social support outcomes of heterosexual couples who have conceived an infant through identity-release egg donation? SUMMARY ANSWER: Parents' scores on all measures were within the normal range. Egg donation mothers had poorer perceived social support, and egg donation fathers had less optimal psychological health than a comparison group of IVF parents, although these differences were associated with the older age of egg donation parents, rather than being an effect of family type. WHAT IS KNOWN ALREADY: There is limited understanding of the psychological health and couple relationship quality of egg donation parents, and no empirical data on parents' social support, during the first year of parenthood. No studies have included families who have used an identity-release egg donor. The study offers the first examination of the psychological well-being of identity-release egg donation parents. STUDY DESIGN, SIZE, DURATION: This study included 57 families created through identity-release egg donation, and a comparison group of 56 families who had used IVF with their own gametes, recruited through UK fertility clinics. Families were visited at home between October 2013 and June 2015. The sample forms part of a larger study examining family functioning in families created following fertility treatment. PARTICIPANTS/MATERIALS, SETTING, METHOD: All families were heterosexual two-parent families with an infant aged 6-18 months. Mothers and fathers were administered standardised questionnaires assessing psychological health (Edinburgh Postnatal Depression Scale, Trait Anxiety Inventory and Parenting Stress Index-short form), couple relationship quality (Golombok Rust Inventory of Marital State) and perceived social support (Multidimensional Scale of Perceived Social Support). MAIN RESULTS AND THE ROLE OF CHANCE: Scores from the egg donation and IVF parents were within the normal range on all measures. Significant differences were found between the groups indicating less optimal social support in egg donation mothers compared to IVF mothers, and poorer psychological health in egg donation fathers compared to IVF fathers. These differences appeared to be related to the older age of egg donation parents or to twin parenthood, rather than to egg donation per se. No differences were found between the groups in the parents' relationship quality. LIMITATIONS, REASONS FOR CAUTION: It is possible that families who were managing the transition to parenthood less well may have been less likely to participate in research. Fewer IVF than egg donation fathers participated in the study, so the statistical power was lower for comparisons between fathers. WIDER IMPLICATIONS OF THE FINDINGS: The findings are of relevance to UK clinics offering identity-release egg donation. That scores of egg donation parents on measures of psychological well-being were more similar than different to those of IVF parents should prove reassuring to individuals considering this treatment type. As less optimal outcomes were found for egg donation parents on several measures, and these were associated with parental age rather than conception type, it is recommended that clinics discuss with older patients how they may establish a social support network and signpost patients to appropriate post-natal support. STUDY FUNDING, COMPETING INTERESTS: This research was supported by a Wellcome Trust Senior Investigator Award [097857/Z/11/Z] and a CHESS-ESRC studentship. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

The clinical utility of genetic testing of tissues from pregnancy losses.

OBJECTIVE: To map the current testing being undertaken following pregnancy loss across the UK and to examine the clinical utility in terms of identifying a cause for the loss and in identifying couples at risk of an unbalanced liveborn child. DESIGN: Retrospective audit. SETTING: UK, for the year 2014. POPULATION: An audit of 6465 referrals for genetic testing of tissue samples following pregnancy loss. METHODS: Data were obtained by questionnaire from 15 UK regional genetics laboratories. MAIN OUTCOME MEASURES: Data were analysed with respect to gestational age, the presence of identified fetal anomalies, methodologies used, abnormality rates and the presence of a parental balanced rearrangement. RESULTS: Of 6465 referrals a genetic cause was identified in 22% of cases (before 12 weeks' gestation, in 47%; at 12-24 weeks, in 14%; after 24 weeks, in 6%). In 0.4% of cases a balanced parental rearrangement was identified where there was a risk of an affected liveborn child in a future pregnancy. Eighty percent of genetic imbalances identified were aneuploidy or triploidy and could be identified by quantitative fluorescence polymerase chain reaction alone. There was significant variation across the UK in acceptance criteria, testing strategies and thus level of resolution of testing. CONCLUSIONS: Genetic testing of tissues following pregnancy loss identifies a probable cause of fetal demise in 22% of cases, but it is of low clinical utility in identifying couples at risk of a future unbalanced liveborn child. A comprehensive multidisciplinary review is needed to develop proposals for an affordable and equitable service. TWEETABLE ABSTRACT: UK audit of genetic testing of fetal loss shows variation in access to and resolution of analysis.

Surrogate mothers 10 years on: a longitudinal study of psychological well-being and relationships with the parents and child.

STUDY QUESTION: How do the psychological health and experiences of surrogate mothers change from 1 year to 10 years following the birth of the surrogacy child? SUMMARY ANSWER: The psychological well-being of surrogate mothers did not change 10 years following the birth, with all remaining positive about the surrogacy arrangement and the majority continuing to report good mental health. WHAT IS KNOWN ALREADY: Studies have found that surrogates may find the weeks following the birth difficult, but do not experience psychological problems 6 months or 1 year later. Research has also shown that surrogates can form close relationships with the intended parents during the pregnancy which may continue after the birth. STUDY DESIGN, SIZE, DURATION: This study used a prospective longitudinal design, in which 20 surrogates were seen at two time points: 1 year following the birth of the surrogacy child and 10 years later. PARTICIPANTS/MATERIALS, SETTING, METHODS: The 20 surrogates (representing 59% of the original sample) participated in a semi-structured interview and completed self-report questionnaires. Eleven surrogates were gestational carriers and nine surrogates had used their own oocyte (genetic surrogacy). Four were previously known to the intended parents and 16 were previously not known. MAIN RESULTS AND THE ROLE OF CHANCE: Ten years following the birth of the surrogacy child, surrogate mothers scored within the normal range for self-esteem and did not show signs of depression as measured by the Beck Depression Inventory. Marital quality remained positive over time. All surrogates reported that their expectations of their relationship with the intended parents had been either met or exceeded and most reported positive feelings towards the child. In terms of expectations for the future, most surrogates reported that they would like to maintain contact or would be available to the child if the child wished to contact them. None expressed regrets about their involvement in surrogacy. LIMITATIONS, REASONS FOR CAUTION: The sample size of this study was small and the women may not be representative of all surrogates. Therefore the extent to which these findings can be generalized is not known. WIDER IMPLICATIONS OF THE FINDINGS: Contrary to concerns about the potentially negative long-term effect of surrogacy, the findings suggest that surrogacy can be a positive experience for some women at least. These findings are important for policy and practice of surrogacy around the world.

Children of surrogate mothers: psychological well-being, family relationships and experiences of surrogacy.

STUDY QUESTION: What impact does surrogacy have on the surrogates' own children? SUMMARY ANSWER: The children of surrogate mothers do not experience any negative consequences as a result of their mother's decision to be a surrogate, irrespective of whether or not the surrogate uses her own egg. STUDY DESIGN, SIZE AND DURATION: Participants were recruited as part of a study of the long-term effects of surrogacy for surrogates and their family members. Data were collected from 36 children of surrogates at a single time point. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants whose mother had been a surrogate 5-15 years prior to interview and who were aged over 12 years were eligible to take part. Thirty-six participants (14 male and 22 female) aged 12-25 years were interviewed (response rate = 52%). Questionnaires assessing psychological health and family functioning were administered. MAIN RESULTS AND THE ROLE OF CHANCE: Forty-four per cent (15) of participants' mothers had undergone gestational surrogacy, 39% (14) had used their own egg (genetic surrogacy) and 19% (7) had completed both types of surrogacy. Most surrogates' children (86%, 31) had a positive view of their mother's surrogacy. Forty-seven per cent (17) of children were in contact with the surrogacy child and all reported good relationships with him/her. Forty per cent (14) of children referred to the child as a sibling or half-sibling and this did not differ between genetic and gestational surrogacy. Most children (89%, 32), reported a positive view of family life, with all enjoying spending time with their mother. Mean scores on the questionnaire assessments of psychological health and self-esteem were within the normal range and did not differ by surrogacy type. LIMITATIONS, REASONS FOR CAUTION: The sample size for this study was relatively small and not all children chose to take part, therefore their views cannot be known. Nevertheless, this is the first study to assess the experiences of surrogacy from the perspective of the surrogates' own children. There may be some bias from the inclusion of siblings from the same family. WIDER IMPLICATIONS OF THE FINDINGS: Findings of this study show that family relationships within the surrogate's own family are good and that the children are not negatively affected as a result of their mother's decision to be a surrogate. These results are of importance to counsellors and support groups offering advice to surrogates and intended parents. STUDY FUNDING, COMPETING INTERESTS: This work was supported by the Economic and Social Research Council (grant number ES/I009221/1). None of the authors has any conflict of interest to declare.

Chimerism in skin of bone marrow transplant recipients.

Skin biopsies from 3 patients receiving one-haplotype-matched bone marrow grafts have provided a unique opportunity to demonstrate the presence of donor cells in situ using immunohistological techniques and a monoclonal antibody directed against an epitope common to HLA-A2 and HLA-A28 antigens. The infiltrating cells were also analyzed in consecutive tissue sections with a panel of monoclonal antibodies to human leukocyte antigens, T cells, and epidermal Langerhans cells. Most of the infiltrating cells were shown to be T lymphocytes of donor origin, regardless of whether the histological changes were consistant with graft-versus-host disease (GVHD) or were eczematous. Donor T cells were also shown to colonize histologically normal skin soon after transplantation. Epidermal keratinocytes, dermal endothelium, and adnexal structures did not express the donor HLA type (i.e., were host derived) but the origin of the epidermal Langerhans cells could not clearly be established. The data show that donor cells preferentially migrate to certain sites in skin after transplantation and are not always associated with GVHD.

Morphological and immunohistological changes in the skin in allogeneic bone marrow recipients.

Skin biopsies from leukaemic patients undergoing allogeneic bone marrow transplantations and treated prophylactically with cyclosporin A were analysed using histological, morphometric, and immunohistological techniques. Samples from donors were used to establish normal values. Biopsies taken from recipients two days before grafting were all histologically normal, but on immunohistological staining half of them showed a reduction in the number of epidermal Langerhans' cells and 29% a reduction in T inducer lymphocytes. Thirty two biopsies were taken from patients with rashes at various times after transplantation: 14 showed lichenoid changes consistent with graft versus host disease, three eczematous tissue reactions, two vesicular lesions, and 12 no histological abnormality. One sample showed changes intermediate between the lichenoid and eczematous forms. The numbers of epidermal Langerhans' cells were low during the first few weeks after transplantation and were normal or raised later regardless of histological appearances. Unlike epidermal Langerhans' cells, significant reductions in the numbers of lymphocytes were not seen. Lesions of all histological types contained mixtures of T inducer and T suppressor/cytotoxic cells, although the eczematous and vesicular lesions contained higher proportions of T inducer cells. Epidermal infiltrates invariably contained T suppressor/cytotoxic cells but infiltration of epidermis by T inducer cells occurred only in the presence of normal numbers of epidermal Langerhans' cells. Natural killer cells were not identified. The immunological appearances of the various histological subgroups thus change with time after transplantation.

Enzyme-antienzyme method for immunohistochemistry.

Immunohistochemical stains use antibodies to identify specific constituents in tissue sections. In order to detect the site of reaction, the antibody is labeled with an enzyme that can be reacted with a suitable substrate to give a colored product. The alternative is to use a fluorescent label. The advantage of an enzyme label is that the nuclei can be counterstained, thereby revealing the tissue architecture, and that the stain fades slowly, if at all, with time, allowing the slides to be stored.

Enzyme-antienzyme method for immunohistochemistry.

Immunohistochemical stains use antibodies to identify specific constituents in tissue sections. In order to detect the site of reaction, the antibody is labeled with an enzyme that can be reacted with a suitable substrate to give a colored product. The alternative is to use a fluorescent label. The advantage of an enzyme label is that the nuclei can be counterstained, thereby revealing the tissue architecture, and that the stain fades slowly, if at all, with time, allowing the slides to be stored.

Detection of isolated mammary carcinoma cells in marrow of patients with primary breast cancer.

Single cells from mammary carcinoma infiltrating bone marrow can be detected in marrow aspirates using immunocytochemical stains for epithelial membrane antigen (EMA). This technique has been used to examine marrow aspirates taken from multiple sites from 24 patients at surgery for breast cancer. Ten of these patients had EMA-positive cells in their marrow, while 32 marrow samples from patients who did not have carcinoma were negative. These results have been combined with those obtained by taking aspirates from single sites from 47 breast patients without known skeletal deposits. Follow up showed that the patients with EMA-positive cells in their marrow developed bone metastases at a significantly faster rate.

A clinical and radiographic study of the "safe area" using the direct lateral approach for total hip arthroplasty.

The purpose of this clinical and radiographic study is to determine whether the surgeon can remain within the 5 cm "safe zone" while using the direct lateral approach during total hip arthroplasty (THA) without endangering the superior gluteal nerve. The direct lateral approach was used in a prospective, consecutive series of 36 primary THAs in 31 patients performed by one surgeon. At the time of closure of the abductor muscle layer, a small metallic clip was placed at the superior extent of the incision into the gluteus medius. After surgery, the patients were mobilized on crutches with protected weight bearing for either a 6-week (hybrid THA) or 12-week (uncemented THA) period. Before surgery, and at 3, 6, and 12 months after surgery, abductor strength and the Trendelenburg sign were measured by the same physical therapist. The vertical distance from the superior pole of the greater trochanter to the base of the clip was measured on all radiographs of the pelvis and corrected for magnification. Before surgery, only 25 of the 36 hips demonstrated abduction strength of 4/5 or greater. Three months after surgery, 34 hips had a grade of 4/5 or greater for abductor strength. The Trendelenburg sign was positive in 24 of 34 hips before surgery, in 5 hips at 3 months, in 1 hip at 6 months, but negative in all hips by 12 months. The clip was located 3.2 +/- 1.3 cm (mean +/- SD) vertically from the superior pole of the greater trochanter. In 34 of 36 hips (95%), the 5 cm safe zone was respected.(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative templating for the equalization of leg lengths in total hip arthroplasty.

The method and results of preoperative templating for the re-establishment of leg length equality during total hip replacement (THR) are reported. The method is a modification of the technique of Müller and requires an anteroposterior radiograph of the pelvis that includes the proximal third of both femora, appropriate acetabular and femoral templates, and tracing paper. To obtain equalization of leg lengths and tissue tension, a composite drawing is made of the operative plan, with all component sizes and important measurements clearly marked. During THR, the lesser trochanter is identified and the femoral neck is osteotomized after a direct measurement is made. These principles were followed in a prospective, consecutive series of 42 primary THR procedures performed by one surgeon. All the radiographic measurements were performed by a single observer. The leg length discrepancy on the postoperative radiograph averaged 3mm (standard deviation = 3mm, range: -9 to +9mm). The postoperative clinical leg length discrepancy averaged 0mm (range: -10 to +10mm). None of the patients complained of leg length inequality. Preoperative templating allows different alternatives to be traced on paper prior to the actual surgical procedure. This method also helps determine the requirements for special prosthetic implants. Acceptable results for postoperative leg length equality may be reliably achieved using this method.

Sliding trochanteric osteotomy preserves favorable abductor biomechanics in revision total hip arthroplasty.

The outcome of sliding trochanteric osteotomy in revision total hip arthroplasty was assessed by comparing preoperative and postoperative static radiographic biomechanics and clinical hip abductor function of 22 consecutive operations (20 patients). Preoperative and postoperative pelvic radiographs were reviewed to quantify the biomechanical reconstruction of the hip abductor mechanism. Abductor muscle length and abductor moment arm were increased significantly (P <.05) by the operation. There was a significant (P <.05) increase in maximum degrees of active hip abduction from the preoperative to the postoperative state, an average of 32 months (range, 6-65 months) after surgery. The dysfunction index (a radiographic representation of hip torque) correlated positively (r =.63; P <.05) with active hip abduction. Sliding trochanteric osteotomy improves abductor biomechanics and may protect against trochanteric migration in revision total hip arthroplasty.

The use of antisera to epithelial membrane antigen in detecting micrometastases in histological sections.

We have investigated, by immunocytochemical means, the value of an antiserum raised to milk-fat-globule membranes in detecting metastatic deposits of breast carcinoma in conventional histological sections of liver, lymph nodes and marrow. The antiseum recognizes a membrane component, which we have called Epithelial Membrane Antigen, and which is confined to but widely distributed in epithelial tissues and tumours derived from them. In the sections examined, a greater extent of tumour infiltration was usually found, largely due to the identification of single malignant cells which normally go unrecognized with conventional stains. The number of positive samples was only increased, however, in sections of marrow aspirates, and the reasons for this are discussed. We suggest that further increases in detection rates could be attained by using the antiserum on cytological smears of marrow or even in cell suspensions.

Detailed investigation of the diagnostic value in tumour histopathology of ICR.2, a new monoclonal antibody to epithelial membrane antigen.

The production and detailed immunostaining properties of a new rat monoclonal antibody (ICR.2) to epithelial membrane antigen are reported. The antibody was selected for its ability to compete with the polyclonal antiserum (M7), used in the original immunohistological studies, in order that it might serve as a direct replacement in diagnosing epithelial tumours. Most of the staining reactions on normal tissues were identical to those previously reported with M7 but there were some important differences. They included: positivity of renal and adrenal capsular fibroblasts, perineurium, some myoepithelial and smooth muscle cells, occasional osteoblasts and squamous and thyroid follicular epithelium in the normal state. The intercellular canaliculi of sweat glands and secretory canaliculi of gastric oxyntic cells were clearly demonstrated. These staining reactions could be obtained with M7 when a sensitive detection system was used although the results were usually weak and inconsistent. Nearly all adenosquamous and transitional carcinomas were positive. The remaining tumours fell into three major groups: (1) those which were consistently or nearly consistently negative--melanoma, seminoma, rhabdomyosarcoma, alveolar soft part sarcoma, adrenal cortical carcinoma, granulocytic sarcoma, paraganglioma, non-Hodgkin's lymphoma. Hodgkin's disease and embryonal carcinoma: (2) those which were either negative or positive with distinctive patterns of staining--basal cell carcinoma, embryonal tumours: and (3) non-epithelial tumours that were consistently positive--epithelioid sarcoma, synovial sarcoma, osteosarcoma, chordoma and myeloma--or positive in a significant minority of cases--leiomyosarcoma, malignant fibrous histiocytoma, clear cell sarcoma of tendon sheath, various neuroectodermal tumours.(ABSTRACT TRUNCATED AT 250 WORDS)