Antibody-dependent lymphocytotoxicity induced by immunoglobulin G from Hodgkin's disease splenic lymphocytes.

Immunoglobulin G, produced in cultures of splenic lymphocytes obtained from patients with Hodgkin's disease, bound to a population of homologous peripheral blood lymphocytes and initiated antibody-dependent cell cytotoxicity in cultures from five out of eight patients. Two patients whose cultures produced negative results had minimal disease; the other was in remission. The target cells appear to be T lymphocytes; the effector cells bear Fc receptors that are inhibited by antigen-antibody complexes. Antibody-dependent cell cytotoxicity events may produce the anergy and lymphopenia often seen in Hodgkin's disease.

Peptides derived from murine insulin are diabetogenic in both rats and mice, but the disease-inducing epitopes are different: evidence against a common environmental cross-reactivity in the pathogenicity of type 1 diabetes.

Two rodent models of autoimmune type 1 diabetes have been used to investigate the role of insulin as an autoantigen in this disease. In lymphopoenia-induced diabetes in the PVG.RT1u rat, neonatal tolerization with insulin B-chain peptides, but not A-chain peptides, conferred significant protection from disease. After rechallenge of adult rats, neonatally B-chain-tolerized animals showed diminished B-chain-specific T-cell proliferation, interleukin (IL)-2 production, and interferon-gamma (IFN-gamma) production, as compared with control animals. The epitope recognized by the PVG.RT1u rat was mapped to residues 1-18 of the B-chain; T-cell lines specific for this epitope were generated, and these conferred diabetes upon adoptive transfer to irradiated syngeneic recipients. In adult nonobese diabetic (NOD) mice, subcutaneous immunization with B-chain peptide 9-23 emulsified in incomplete Freund's adjuvant (IFA) was also potent at preventing onset of diabetes. In contrast to PVG.RT1u rats, NOD mice recognized an epitope within residues 10-29 of the insulin B-chain. The data implicate insulin as a target autoantigen in type 1 diabetes but do not support a role for molecular mimicry to insulin in the pathogenesis of this disease.

Hematologic evaluation of employees with leukopenia. Naval Weapons Center, China Lake, California.

Evaluation of 86 employees with a history of leukopenia at the Naval Weapons Center (NWC), China Lake, California, was done by exposure questionnaires, medical histories, physical examinations, peripheral blood smear, and bone marrow evaluations, including morphologic examination, stem cell culture, and cytogenetics. Forty-eight subjects were found to be leukopenic at the time of the study, and two subjects were found to have hairy cell leukemia. All subjects had positive exposure histories and were healthy at the time of the study. Review of peripheral smears identified the patients with marrow abnormalities. Bone marrow cultures revealed several patients with possible marrow suppression. Chromosome studies were not diagnostic. Five-year follow-up health questionnaires revealed no significant health problems; the two workers with hairy cell leukemia are alive and fully functional. Leukopenia in itself does not appear to be a risk factor for poor health, and it is unknown whether or not it may be a useful screening tool to identify workers at risk in toxic environments. Careful evaluation of blood cell counts and peripheral smears should be sufficient to identify people with potential marrow abnormalities.

Cervical length at 23 weeks in twins in predicting spontaneous preterm delivery.

OBJECTIVE: To establish the relationship between cervical length at 23 weeks' gestation in twin pregnancies and risk of spontaneous preterm delivery. METHODS: Cervical length was measured during routine antenatal care by transvaginal sonography at 23 (range 22-24) weeks' gestation in 215 twin pregnancies. Distribution of cervical length was determined, and sensitivity and false-positive rate for spontaneous preterm delivery at or before 28, 30, 32, and 34 weeks for cutoff cervical lengths of 15, 25, 35, and 45 mm were calculated. RESULTS: Cervical length distribution was skewed toward shorter length and the median value was 38 mm. In 11.2% and 4.2% of cases, length was up to 25 mm and up to 15 mm, respectively. The spontaneous delivery rates at or before 28, 30, 32, and 34 weeks were 3.8%, 4.7%, 8.0%, and 17.5%, respectively, and were not statistically significantly related to any demographic characteristics, obstetric history, or chorionicity. Sensitivity to predict spontaneous preterm delivery was 100%, 80%, 47%, and 35% for 28, 30, 32, and 34 weeks, respectively, for cervical length up to 25 mm. The corresponding sensitivity values for cervical lengths up to 15 mm were 50%, 40%, 24%, and 11%. The rate of spontaneous delivery at or before 32 weeks increased exponentially with decreasing cervical length at 23 weeks, from 2.9% at or greater than 46 mm, to 4.3% at 36-45 mm, 6.7% at 26-35 mm, 31% at 16-25 mm, and 66% at 15 mm or less. CONCLUSION: Measurement of cervical length in twin pregnancies predicted risk of spontaneous early preterm delivery.

One-stop clinic for assessment of risk of chromosomal defects at 12 weeks of gestation.

Prenatal diagnosis of trisomy 21 requires an invasive test in women considered to be at high risk after screening. At present, there are four screening tests. For a 5% false-positive rate, the sensitivities are approximately 30% for maternal age alone, 60-70% for maternal age and second-trimester maternal serum biochemical testing, 75% for maternal age and first-trimester fetal nuchal translucency (NT) scanning, and 90% for maternal age with fetal NT and maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11-14 weeks. This article examines the methodology of first-trimester screening and summarizes the results from all studies reporting on the implementation of this method.

Juvenile fibromatosis.

Juvenile fibromatosis is a benign lesion with locally aggressive characteristics. Wide surgical excision is the treatment of choice. Radiation therapy can be used for inoperable cases or as adjunctive therapy. Steroid therapy has not been used extensively and deserves further evaluation. In the head and neck area, juvenile fibromatosis must be very carefully diagnosed and treated due to the serious consequences that result from inadequate control.

Accreditation of Prior (Experiential) Learning: making the difference.

This paper considers the use of Accreditation of Prior (Experiential) Learning (AP[E]L) in pre registration nurse education. AP(E)L has opened up many new prospects in post registration nurse education but opportunities for pre registration have, to date, been few. The time for change, however, is upon us all, most particularly for those institutions which have been selected to develop a new approach to nurse education referred to in Making a Difference, published by the Department of Health in 1999 and Fitness for Practice, published by the UKCC in 1999. As one of the selected sites the Institute of Health Studies at the University of Plymouth, in conjunction with the Cornwall and South Devon and Somerset and North Devon Education Purchasing Consortia, is in the process of implementing those required changes. One of the changes integral to the new curriculum is that of AP(E)L for entry to, and exit from, pre registration nurse education.

TSC-22D1 isoforms have opposing roles in mammary epithelial cell survival.

Transforming growth factor beta (TGFbeta)-stimulated clone-22 domain family member 1 (TSC-22D1) has previously been associated with enhanced apoptosis in several cell systems. In an attempt to identify novel factors that are involved in the control of cell death during mammary gland involution, we found that the mRNA for isoform 2 of TSC-22D1 was highly upregulated 24 h after forced weaning, when a dramatic increase in cell death occurred, closely following the expression of the known inducer of cell death during involution, TGFbeta3. This was paralleled by strongly increased TSC-22D1 isoform 2 protein levels in the luminal epithelium. In contrast, RNA and protein expression levels of the isoform 1 of TSC-22D1 did not change during development. Whereas isoform 2 induced cell death, isoform 1 suppressed TGFbeta-induced cell death and enhanced proliferation in mammary epithelial cell lines. Furthermore, four distinct forms of isoform 2 protein were detected in the mammary gland, of which only a 15-kDa form was associated with early involution. Our data describe novel opposing functions of the two mammalian TSC-22D1 isoforms in cell survival and proliferation, and establish the TSC-22D1 isoform 2 as a potential regulator of cell death during mammary gland involution.

Ethnicity and the need for correction of biochemical and ultrasound markers of chromosomal anomalies in the first trimester: a study of Oriental, Asian and Afro-Caribbean populations.

OBJECTIVES: To assess whether there is a need to correct first-trimester biochemical markers (free beta-hCG and pregnancy-associated plasma protein-A (PAPP-A)) or first-trimester fetal nuchal translucency thickness (NT) in different ethnic groups, when screening for Downs syndrome at 11-14 weeks of gestation. METHODS: Free beta-hCG, PAPP-A and fetal NT were measured at 11-14 weeks of gestation in a group of women presenting for first-trimester screening in two OSCAR centres. The group comprised 61 219 sets of data from Caucasian women (the reference group); 4835 sets of data from South Asian women; 3450 sets of data from Oriental women and 2727 sets of data from Afro-Caribbean women. The Oriental data set was supplemented with a further 480 cases collected in Hong Kong and the Afro-Caribbean data set was supplemented with 216 cases collected from Kings College. The difference in marker values between the reference group and the other ethnic groups was compared before and after weight correction for the biochemical markers using standard statistical techniques. A correction factor for ethnic origin was applied for all three markers and the screen-positive rate before and after correction was assessed for the various groups. RESULTS: After maternal weight correction, in Afro-Caribbean women, the median PAPP-A was increased by 55% and the free beta-hCG increased by 11%. In south Asian women, the PAPP-A was increased by 8% and the free beta-hCG decreased by 7.5%. In Oriental women, the PAPP-A was increased by 9% and the free beta-hCG by 6%. For delta NT in Afro-Caribbean women, the values were 0.064 mm lower on average than in Caucasian women and for south Asian women 0.045 mm lower. The difference of -0.012 for Oriental women was not significant. Before correcting for ethnic origin, these changes resulted in the screen-positive rates being lower in the Afro-Caribbean group (3.7% vs 5.6%), the south Asian group (4.3% vs 5.6%) and Oriental group (4.9% vs 5.6%). After correction, the screen-positive rates were largely similar in the four groups. CONCLUSION: Differences in median PAPP-A, free beta-hCG and, to a lesser extent, in NT exist in Afro-Caribbean, South Asian and Oriental women. In populations where the medians and delta NT reference ranges are established in predominantly Caucasian populations, some correction for ethnicity is appropriate and can redress differences in screen-positive rates between these different groups.

Human myeloma IgG half-molecules. Structural and antigenic analyses,.

The structure and antigenic characteristics of a human k, IgG myeloma protein that formed half-molecules were analyzed. Most of the myeloma protein found in the patient's serum and urine consisted to two chain 4.3S half-molecules. A small amount of four chain 7S myeloma protein was, however, found in the serum and was apparently formed by the same clone of tumor cells. Polyacrylamide gel electrophoresis in 8 M urea and 1% sodium dodecyl sulfate and analytical ultracentrifugation in 6 M guanidine of the fully reduced and alkylated half-molecule indicated that this myeloma protein had a heavy chain of a smaller molecular weight (approximately 45,000) than that of normal gamma chains, Except for this apparent deletion, the heavy chain resembled gamma1 chains. The amino acid composition of the peptides containing the half-cysteine residues forming the interchain disulfide bonds, the glycopeptide of the Fc fragment and the COOH-terminal structure were similar if not identical with the analogous structures of gamma1 chains. No Fc fragment could be prepared because the Fc portion of the heavy chain of the myeloma protein was extremely susceptible to degradation with papain. After mild reduction and alkylation, the 7S myeloma protein dissociated into half-molecules, indicating a lack of noncovalent interactions in the Fc fragment that are present in all classes of human immunoglogulins and are responsible for the formation ofFc dimers. The half-molecule was antigenically deficient in the Fc fragment. It failed to precipitate with anti-Fc fragment antisera in double gel diffusion tests and inhibited a Fc-anti-Fc fragment binding reaction weakly and incompletely. The half-molecule and the 7S protein had the same genetic markers on the first and second homology region of the gamma chain. The half-molecule lacked, however, the corresponding markers on the third homology region, These findings suggest that this myeloma protein had a deletion in the gamma chain which was probably located in third homology region and was likely the structural abnormality responsible for the lack of noncovalent interaction in the Fc fragment and absence of most of the antigenic determinants characteristic of gamma chains.

Homeostatic mechanisms in the control of autoimmunity.

The data in this article challenge the current paradigm that self tolerance among T cells can be fully accounted for in terms of intrathymic clonal deletion, anergy and T-cell 'indifference'. We show that autoreactive T cells are under the control of a dominant T-cell-mediated control mechanism and that the thymus is a particularly potent source of these protective cells. We further show that 'peripheral' self antigens implicated in autoimmune diseases are expressed intrathmically and we consider possible consequences of such expression. Finally we show that autoantigen-specific peripheral T cells can be programmed to prevent autoimmunity.

IgG half-molecules: clinical and immunologic features in a patient with plasma cell leukemia.

The clinical manifestations and immunologic features of a patient with plasma cell leukemia who produced k, IgG half-molecules are described. His serum contained both 7S myeloma protein and 4.3S half-molecules, whereas his urine contained predominantly half-molecules. The half-molecules were discovered because the serum and urine formed double precipitin lines when analyzed by commercially available IgG radial immunodiffusion plates that contained antibodies to determinants on both the Fab and Fc fragments. Immunoelectrophoresis also revealed double precipition lines with such antisera. In contrast, when antisera specific for the IgG Fc fragment were used, the serum showed only a single line formed by intact IgG, and the urine failed to react, indicating that the half-molecule was antigenically deficient in the Fc fragment. The half-molecule consisted of one covalently linked heavy and light chain, both having about normal molecular weights, suggesting that they did not have a large deletion which could have caused the half-molecule production. Comparison of the clinical manifestations of the patient with those of four other known patients who produced half-molecules suggested that half-molecule formation is not associated with a distinct clinical syndrome.

Inhibition of the terminal stages of adipocyte differentiation by cMyc.

The nuclear oncoprotein Myc is a pivotal regulator of several important biological processes, including cellular proliferation, differentiation, and apoptosis. Deregulated Myc expression is incompatible with terminal differentiation in a variety of cell types, including adipocytes. To understand how Myc inhibits adipogenesis, we analyzed the effect of Myc on the expression of genes characteristic of distinct phases of the hormonally induced adipogenic differentiation program in 3T3-L1 preadipocytes. We show that the early regulators, C/EBPbeta and C/EBPdelta, are induced normally in response to hormone in 3T3-L1 preadipocytes constitutively expressing Myc, but that expression of the downstream regulators, C/EBPalpha and PPARgamma2, and later markers of differentiation is suppressed. These data demonstrate that Myc specifically inhibits the terminal stages of the adipogenic program and suggest that Myc may act by blocking C/EBPbeta- and C/EBPdelta-directed activation of C/EBPalpha and PPARgamma2 expression, although the precise molecular mechanism is not understood. Surprisingly, a serum component(s) could override the Myc-induced differentiation block, suggesting that the ability of a cell to undergo terminal differentiation is governed by the action of both positive and negative factors. Since differentiation and proliferation are mutually exclusive events, this has important implications since it may be possible to force malignant cells along a differentiation pathway, thereby curbing their proliferative potential.

Inhibition of adipocyte differentiation by cMyc is not accompanied by alterations in cell cycle control.

Using a preadipocyte cell line constitutively expressing cMyc, we set out to determine if the ability of cMyc to inhibit adipogenic differentiation was functionally distinct from its role in cell cycle progression and transformation. We now report that in this system differentiation control and cellular transformation are separable functions of cMyc. Furthermore, the Myc-induced inhibition of adipocyte differentiation appears to be mediated via suppression of C/EBP-alpha and p21 gene expression late in the adipogenic differentiation programme, without deregulation of either cell cycle control or gene expression during the early stages of the process.

The 11-14 week scan.

Fetal nuchal translucency thickness (NT) at the 11-14 week scan has been combined with maternal age to provide an effective method of screening for trisomy 21; for an invasive testing rate of 5%, about 75% of trisomic pregnancies can be identified. When maternal serum free-beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A at 11-14 weeks are also taken into account, the detection rate of chromosomal defects is about 90%. Increased NT can also identify a high proportion of other chromosomal abnormalities and is associated with major defects of the heart and great arteries, and a wide range of skeletal dysplasias and genetic syndromes. Other benefits of the 11-14 week scan include early diagnosis of major fetal defects and the detection of multiple pregnancies, as well as reliable identification of chorionicity. As with the introduction of any new technology into routine clinical practice, it is essential that those undertaking the 11-14 week scan are adequately trained and that their results are subjected to rigorous audit.

Humanization of a mouse monoclonal antibody by CDR-grafting: the importance of framework residues on loop conformation.

A mouse monoclonal antibody (mAb 425) with therapeutic potential was 'humanized' in two ways. Firstly the mouse variable regions from mAb 425 were spliced onto human constant regions to create a chimeric 425 antibody. Secondly, the mouse complementarity-determining regions (CDRs) from mAb 425 were grafted into human variable regions, which were then joined to human constant regions, to create a reshaped human 425 antibody. Using a molecular model of the mouse mAb 425 variable regions, framework residues (FRs) that might be critical for antigen-binding were identified. To test the importance of these residues, nine versions of the reshaped human 425 heavy chain variable (VH) regions and two versions of the reshaped human 425 light chain variable (VL) regions were designed and constructed. The recombinant DNAs coding for the chimeric and reshaped human light and heavy chains were co-expressed transiently in COS cells. In antigen-binding assays and competition-binding assays, the reshaped human antibodies were compared with mouse 425 antibody and to chimeric 425 antibody. The different versions of 425-reshaped human antibody showed a wide range of avidities for antigen, indicating that substitutions at certain positions in the human FRs significantly influenced binding to antigen. Why certain individual FR residues influence antigen-binding is discussed. One version of reshaped human 425 antibody bound to antigen with an avidity approaching that of the mouse 425 antibody.

The relationship between perceived dysfunctional family-of-origin rules and intimacy in young adult dating relationships.

This study examined the relationship between perceived dysfunctional family-of-origin rules and intimacy in single young adult dating relationships. A sample of 754 single, Caucasian-American young adults completed measures of perceived dysfunctional family-of-origin rules and emotional, intellectual, and sexual intimacy in dating relationships. When controlling for the effects of gender and age, results showed that perceived dysfunctional family-of-origin rules had a negative impact on the perceived expression and experience of these three kinds of intimacy in dating relationships. Implications for relationship therapy are discussed.

Should tissue from pregnancy termination and uterine evacuation routinely be examined histologically?

OBJECTIVE: To assess the value of routine histological examination of tissue samples collected at termination of pregnancy in the first trimester and emergency surgical uterine evacuation. SETTING: The gynaecological department of a teaching hospital. DESIGN: Prospective study of women attending the gynaecological department in a 12-month period. PARTICIPANTS: All women undergoing a therapeutic first trimester medical or surgical abortion or an emergency surgical evacuation of a failed pregnancy, suspected incomplete spontaneous miscarriage or incomplete induced abortion. MAIN OUTCOME: Association of pre-operative clinical diagnosis and the post-operative histological result. RESULTS: Of 1,576 women studied, the histological report confirmed that products of conception were obtained in 1,465 (93%); in two women (0.13%) molar changes were reported confirming the preoperative diagnosis by ultrasound. Products of conception were not confirmed in the tissue specimens in 0.5% medical terminations, 5% surgical terminations, 10% evacuations following a previous evacuation, 12% evacuations for a failed pregnancy, and 19% evacuations for an incomplete miscarriage. In 87 women (6%), decidua was reported; two of these women had undergone an evacuation for an ultrasound diagnosis of spontaneous miscarriage, but in both a tubal ectopic pregnancy was subsequently diagnosed. CONCLUSION: There did not appear to be any obvious benefit from routine histological examination of tissue removed at termination of pregnancy or emergency uterine evacuation. The histological result was sometimes not consistent with the pre-operative diagnosis and may result in unnecessary further investigation and treatment unless due consideration is given to the clinical presentation.