Oxfordshire Women and Their Children's Health (OxWATCH): protocol for a prospective cohort feasibility study

INTRODUCTION

Some specific pregnancy disorders are known to be associated with increased incidence of long-term maternal ill health (eg, gestational diabetes with late onset type 2 diabetes; pre-eclampsia with arterial disease). To what degree these later health conditions are a consequence of the woman's constitution prior to pregnancy rather than pregnancy itself triggering changes in a woman's health is unknown. Additionally, there is little prospective evidence for the impact of pre-pregnancy risk factors on the outcome of pregnancy. To understand the importance of pre-pregnancy health requires the recruitment of women into a long-term cohort study before their first successful pregnancy. The aim of this feasibility study is to test recruitment procedures and acceptability of participation to inform the planning of a future large-scale cohort study.

METHODS

The prospective cohort feasibility study will recruit nulliparous women aged 18-40 years. Women will be asked to complete a questionnaire to assess the acceptability of our recruitment and data collection procedures. Baseline biophysical, genetic, socioeconomic, behavioural and psychological assessments will be conducted and samples of blood, urine, saliva and DNA will be collected. Recruitment feasibility and retention rates will be assessed. Women who become pregnant will be recalled for pregnancy and postpregnancy assessments.

ETHICS AND DISSEMINATION

The study protocol was approved by South Central Portsmouth REC (Ref: 12/SC/0492). The findings from the study will be disseminated through peer reviewed journals, national and international conference presentations and public events.

TRIAL REGISTRATION NUMBER

http://www.clinicaltrials.gov; NCT02419898.

Migrant health and infectious diseases in the UK: findings from the last 10 years of surveillance

BACKGROUND

Migrants account for an increasing proportion of the UK population. They are at risk of acquiring infectious diseases in their country of origin (prior to migration or during return visits), during migration, as well as in their destination country. Migrants can therefore have different risk profiles to the indigenous population.

METHODS

UK enhanced surveillance data for TB, HIV, malaria and enteric fever were analysed, with a focus on 2010, for migrant (non-UK born) populations.

RESULTS

South Asia was the most common region of birth for TB and enteric fever cases (57 and 80% of migrant cases, respectively). Sub-Saharan Africa was the predominant region of birth for HIV in heterosexuals and malaria cases (80 and 75% of migrant cases, respectively). The majority of cases of TB, HIV in heterosexuals, malaria and enteric fever reported in the UK are migrants. Among UK-born cases, ethnic minorities are disproportionately represented.

CONCLUSIONS

This analysis highlights the importance of considering, and improving the recording of, country of birth as a risk factor for infection. Consideration of multiple health risks is of value for migrant patients, and this has implications for the design of improved preventative strategies.

OS045. Multi-dimensional protein identification technology analysis of syncytiotrophoblast vesicles released from perfused preeclampsia placentas

INTRODUCTION

In pre-eclampsia, the consequences of poor placentation lead to the second stage of pre-eclampsia, which involves activation of a maternal systemic inflammatory response (MSIR). Endothelial and other inflammatory cellular dysfunction cause the diverse features which characterise the disorder. We have previously shown that syncytiotrophoblast microvesicles (STBM) are pro-inflammatory and circulate in increased amounts in pre-eclamptic women. We hypothesise that multiple placental "danger signals" are carried by STBM into the maternal circulation in increased amounts in PE with pro-inflammatory, anti-angiogenic and pro-coagulant activity, implicating STBM in the pathophysiology of PE.

OBJECTIVES

To characterise the proteins carried by STBM from normal and PE placentas. For the first time multi-dimensional protein identification technology (MudPIT) was used to derive the proteome profiles of normal and PE placenta STBM.

METHODS

STBM were prepared from placentas (normal term: n=9 and PE: n=5) by dual lobe perfusion, isolated by ultracentrifugation and stored at -80°C. Normal and PE derived placenta STBM pools were then subjected to MudPIT analysis.

RESULTS

538 proteins unique to PE STBM, 604 proteins unique to normal STBM and 1421 proteins common to both preparations were found. Preliminary analysis indicates the presence of alarmins (HSP70, and galectin 3), exosomal proteins (CD63,CD9,CD81), immunoregulatory molecules (CD26,CD200,CD47,Galectin 1), complement and complement regulatory molecules (C1q,C3,CD55,CD59 and vitronectin), amino acid transporters (CD98) and anti-angiogenic molecules (endoglin). Our analysis also reveals that proteins known to be elevated in blood before, or at, the time of pre-eclampsia are elevated or unique in STBM from PE placentas, including Fetuin A, Inter-alpha (globulin) inhibitor H4, Serum amyloid P component, Apolipoprotein H (or B2GP1) and Apolipoprotein AII. Thus, as predicted, a large number of circulating molecules are associated with STBM. The inter-relationships between proteins that are unique to either PE or normal pregnancy and the processes in which they are involved are being determined by Ingenuity Pathways Analysis software. In terms of biofunctions, preliminary analysis shows that proteins unique to PE STBM have a highly significant association (p<10(-11)) with 6 disease pathways including inflammatory, immunological, cardiovascular and reproductive system diseases and organ injury, whereas for proteins unique to normal STBM only protein synthesis was significant at the same level.

CONCLUSION

STBM contain a heterogeneous population of vesicles that convey a large repertoire of placental proteins into the maternal circulation. The profound differences between PE and normal STBM indicate their pro-inflammatory potential.

IFPA Meeting 2011 workshop report I: Placenta: Predicting future health; roles of lipids in the growth and development of feto-placental unit; placental nutrient sensing; placental research to solve clinical problems--a translational approach

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2011 there were twelve themed workshops, four of which are summarized in this report. These workshops related to both basic science and clinical research into placental growth and nutrient sensing and were divided into 1) placenta: predicting future health; 2) roles of lipids in the growth and development of feto-placental unit; 3) placental nutrient sensing; 4) placental research to solve clinical problems: a translational approach.

Micronutrients in pregnancy: current knowledge and unresolved questions

Micronutrient status is increasingly recognized to play an important role in the health and well-being of pregnant women and in the development and long-term health of the offspring. On 26th - 28th February 2009, The Child Health Foundation invited leading experts in this area to a scientific workshop at Obergurgl, Austria to review and critically discuss current knowledge, to identify issues that may need to be addressed in future recommendations, and to highlight priorities and opportunities for future research. This report summarizes updated key conclusions of the workshop with regards to micronutrients' intake and physiological role related to mother, placenta and fetus, as well as relevance for adverse pregnancy and long-term outcomes.

Effect of syncytiotrophoblast microvillous membrane treatment on gene expression in human umbilical vein endothelial cells

OBJECTIVE

Syncytiotrophoblast membrane fragments (STBM) exist in the peripheral circulation in pregnant women and it has been shown that the level of circulating STBM is significantly increased with pre-eclampsia compared with uncomplicated pregnancies. STBM could be one of the factors which directly causes the endothelial cell dysfunction of pre-eclampsia. This study investigates the effect of STBM on endothelial cell gene expression.

DESIGN

Human umbilical vein endothelial cells were cultured in the presence and absence of STBM. At specified time points, total RNA was purified from the cultures and analysed on microarrays.

SETTING

A laboratory investigation using placentas obtained from a hospital delivery ward.

SAMPLE

Placentas from nine healthy women were obtained. STBM vesicles were isolated from the placentas and umbilical vein endothelial cell cultures were established from the umbilical cords.

METHODS

Gene expression was screened by Affymetrix GeneChips and confirmed with real-time polymerase chain reaction or enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURES

Fold changes in gene expression levels between treated and control cultures were calculated from the microarray results.

RESULTS

Overall, the results do not show any great changes in gene expression in endothelial cells after STBM treatment (28 genes changed two-fold or more out of approximately 10,000 genes examined by microarray). In general, the changes observed are consistent with inhibition of proliferation of endothelial cells by exposure to STBM. The unfolded protein response in particular may be involved.

CONCLUSIONS

STBM may influence endothelial cell function during pregnancy but STBM alone cannot account for the entire range of endothelial dysfunctions observed in pre-eclampsia.

What are the factors associated with the follow-up preferences of women in long-term remission from gynaecological cancer?

We set out to examine factors associated with follow up preferences of women attending routine hospital follow up after treatment for early stage gynaecological cancer. This was a retrospective cohort study, using hospital records and questionnaire data, and was based in North Staffordshire, UK. Fifty-four women, who had undergone successful treatment for early stage gynaecological cancer and currently attending routine hospital follow up appointments, were studied. Follow-up preferences were established using a specially designed questionnaire. A questionnaire package containing psychological and demographic measures was used. Clinical details including site and stage of disease, treatment and follow-up type were obtained from medical records. There were no significant demographic or clinical differences between the women with preference for hospital follow-up and those women with a preference for discharge. Women with a preference for follow-up were found to have significantly higher anxiety (as measured by the MAC anxiety scale). These results were not found for the other anxiety scales (STAI and HADS). Three predictor variables (MAC anxiety, Education and Car ownership) were found to predict significantly group membership. It is not possible to predict follow-up needs using demographic, clinical or psychological factors. Follow-up needs are achieved through effective medical communication. The role of the specialist nurse is implicated. A larger scale study is necessary to elaborate this preliminary research.

The relation between pre-eclampsia at term and neonatal encephalopathy

OBJECTIVES

To determine whether pre-eclampsia, hypothesised to be an inflammatory condition, is associated with fever in term labour, and confirm and examine the reported association of pre-eclampsia at term with neonatal encephalopathy.

DESIGN

Prospective cohort study.

SETTING

A Dublin teaching hospital.

PARTICIPANTS

6163 women in labour with singleton pregnancies at term at low risk for intrapartum hypoxia, recruited to a randomised trial examining the effect of admission cardiotocography on neonatal outcome.

RESULTS

Pre-eclampsia was associated with maternal fever > 37.5 degrees in labour (odds ratio (OR) 3.39, 95% confidence interval (CI) 2.1 to 5.4); this was independent of obstetric intervention (adjusted OR 2.07, 95% CI 1.24 to 3.47). Pre-eclampsia was associated with neonatal encephalopathy (OR 25.5, 95% CI 8.4 to 74.7); this too was independent of obstetric intervention (adjusted OR 18.5, 95% CI 5.9 to 58.1). Cord arterial pH values were significantly lower in pre-eclamptics (7.20 v 7.24), although severe cord acidaemia was not significantly more common (OR 2.91, 95% CI 0.7 to 9.9). The association of pre-eclampsia with encephalopathy was independent of maternal fever (adjusted OR 16.5, 95% CI 5.1 to 54) and cord acidaemia (adjusted OR 13.5, 95% CI 3.2 to 56.7).

CONCLUSIONS

The association of pre-eclampsia with maternal fever at term supports the hypothesis that pre-eclampsia is an inflammatory condition. The association of pre-eclampsia with neonatal encephalopathy is independent of obstetric intervention and cannot be explained by either acidaemia or maternal fever. A systemic inflammatory response in the fetus, perhaps secondary to oxidative stress, could explain the link between maternal pre-eclampsia and neonatal encephalopathy, and this may occur through cerebral vasoconstriction.

Kell and XK immunohistochemistry in McLeod myopathy

The McLeod syndrome is an X-linked neuroacanthocytosis manifesting with myopathy and progressive chorea. It is caused by mutations of the XK gene encoding the XK protein, a putative membrane transport protein of yet unknown function. In erythroid tissues, XK forms a functional complex with the Kell glycoprotein. Here, we present an immunohistochemical study in skeletal muscle of normal controls and a McLeod patient with a XK gene point mutation (C977T) using affinity-purified antibodies against XK and Kell proteins. Histological examination of the affected muscle revealed the typical pattern of McLeod myopathy including type 2 fiber atrophy. In control muscles, Kell immunohistochemistry stained sarcoplasmic membranes. XK immunohistochemistry resulted in a type 2 fiber-specific intracellular staining that was most probably confined to the sarcoplasmic reticulum. In contrast, there was only a weak background signal without a specific staining pattern for XK and Kell in the McLeod muscle. Our results demonstrate that the lack of physiological XK expression correlates to the type 2 fiber atrophy in McLeod myopathy, and suggest that the XK protein represents a crucial factor for the maintenance of normal muscle structure and function.

Recurrent acquired sideroblastic anemia in a twin pregnancy

A woman whose sideroblastic anemia had relapsed with progestogen and combined oral contraceptive therapy suffered further relapses in a (twin) pregnancy. Previous reports exist of relapses both from progestogens and in pregnancy, and we postulate a shared etiology. Affected women considering pregnancy or sex hormone usage should be advised accordingly.

Enhanced secretion of ApoB by transfected HepG2 cells overexpressing fibrinogen

HepG2 cells stably transfected with cDNA-encoding single fibrinogen chains overexpress fibrinogen and have increased (4-fold) secretion of apolipoprotein B. Overexpression of fibrinogen does not affect the secretion of three representative acute-phase proteins but causes a small increase in albumin secretion. Enhanced apolipoprotein B secretion is due to less intracellular degradation and not to increased expression. The increased secretion of apolipoprotein B is independent of the acute-phase response, since stimulation of fibrinogen gene expression by interleukin 6 did not affect secretion. HepG2 cells overexpressing fibrinogen chains had increased 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA levels, enhanced cholesterol production but normal levels of triglyceride and phospholipid synthesis and of sterol response binding proteins. These results, that associate overexpression of fibrinogen with enhance apolipoprotein B secretion, may be significant since epidemiological studies indicate that elevated levels of fibrinogen and lipids are independent risk factors in coronary artery disease.

Functional and structural aspects of the Kell blood group system

Two covalently linked proteins, Kell and XK, constitute the Kell blood group system. Kell, a 93-Kd type II glycoprotein, is highly polymorphic and carries all but 1 of the known Kell antigens, and XK, which traverses the membrane 10 times, carries a single antigen, the ubiquitous Kx. The Kell/XK complex is not limited to erythroid tissues and may have multiple physiological roles. Absence of one of the component proteins, XK, is associated with abnormal red cell morphology and late-onset forms of nerve and muscle abnormalities, whereas the other protein component, Kell, is an enzyme whose principal known function is the production of a potent bioactive peptide, ET-3.

The 5'2 promoter of the neuronal nitric oxide synthase dual promoter complex mediates inducibility by nerve growth factor

Neuronal nitric oxide synthase (nNOS) is induced by nerve growth factor (NGF) in pheochromocytoma PC12 cells. Previous studies from our laboratory identified two closely linked promoters (designated 5'1 and 5'2) that mediate transcription of the human nNOS gene in the brain [J. Xie, P. Roddy, T.K. Rife, F. Murad, A.P. Young, Two closely linked but separable promoters for human neuronal nitric oxide synthase gene transcription, Proc. Natl. Acad. Sci. U. S. A. 92 (1995) 1242-1246]. In this report, we demonstrate that luciferase fusion genes under transcriptional control by the 5'1 and 5'2 dual promoter complex are inducible by NGF in stably transformed PC12 cells. In sharp contrast, neither epidermal growth factor (EGF) nor fibroblast growth factor 2 (FGF2) are able to significantly enhance the expression of NOS-luciferase fusion genes. Deletion studies indicate that the 5'2 promoter plays a major role in mediating NGF inducibility. The 5'2 promoter contains six potential Ets binding sites as well as four potential AP1 binding sites. Thus, it is possible that activation of Ets and/or AP1 transcription factors by the Ras-Raf-MAP kinase cascade contributes to the NGF-mediated induction of nNOS.

Intracellular assembly of Kell and XK blood group proteins

Kell, a 93 kDa type II membrane glycoprotein, and XK, a 444 amino acid multi-pass membrane protein, are blood group proteins that exist as a disulfide-bonded complex on human red cells. The mechanism of Kell/XK assembly was studied in transfected COS cells co-expressing Kell and XK proteins. Time course studies combined with endonuclease-H treatment and cell fractionation showed that Kell and XK are assembled in the endoplasmic reticulum. At later times the Kell component of the complex was not cleaved by endonuclease-H, indicating N-linked oligosaccharide processing and transport of the complex to a Golgi and/or a post-Golgi cell fraction. Surface-labeling of transfected COS cells, expressing both Kell and XK, demonstrated that the Kell/XK complex travels to the plasma membrane. XK expressed in the absence of Kell was also transported to the cell surface indicating that linkage of Kell and XK is not obligatory for cell surface expression.

Proteolytic processing of big endothelin-3 by the kell blood group protein

Kell blood group protein shares a consensus sequence (H.E.X.X.H) with a large family of zinc-dependent endopeptidases. Kell has closest homology with neutral endopeptidase 24.11, endothelin converting enzyme-1 (ECE-1), and the PEX gene product that, as a group, comprise the M13 subfamily of mammalian neutral endopeptidases. The proteolytic activity of the M13 members, but not of Kell, has been previously demonstrated. A secreted form of wild-type Kell protein (s-Kell), devoid of the intracellular and transmembrane domains, was expressed in sf9 cells. As a negative control, an inactive mutant Kell protein (E582G) was expressed. As determined by N-terminal amino acid sequencing and mass spectrometry of the cleaved products, wild-type s-Kell, but not the control mutant protein, specifically cleaved big endothelin-3 (ET-3) at Trp(21)-Ile(22), yielding ET-3, and, to a much lesser extent, also cleaved big ET-1 and big ET-2 at Trp(21)-Val(22), yielding ET-1 and ET-2. Enzymatic activity was partially inhibited by phosphoramidon. s-Kell has an acidic pH optimum (pH 6.0 to 6.5). Like the recombinant protein, red blood cells of common Kell phenotype also preferentially process big ET-3, in contrast to Ko (null) cells that do not. These data demonstrate that the Kell blood group protein is a proteolytic enzyme that processes big ET-3, generating ET-3, a potent bioactive peptide with multiple biological roles.

The degradation of nascent fibrinogen chains is mediated by the ubiquitin proteasome pathway

Recent studies have shown that ubiquitin-dependent proteolysis by proteasomes plays an essential role in the degradation of ER-retained proteins. We investigated the degradation of individual fibrinogen chains in transfected COS cells which express but do not secrete single chains. In transfected COS cells, the degradation of fibrinogen Bbeta and gamma chain was markedly inhibited by the proteasome inhibitors lactacystin and MG132. These specific proteasome inhibitors also partially affected the degradation of Aalpha chain. In HepG2 cells, which synthesize and secrete fibrinogen, the degradation of intracellular free gamma chain was also inhibited by MG132. We also detected high molecular weight polyubiquitinated forms of fibrinogen chains in transfected COS cells and in HepG2 cells by sequential immunoprecipitation. These results implicate proteasomes in the degradation of fibrinogen chains. In COS cells, gamma chains have a longer half-life than Bbeta chains and Aalpha chains, suggesting that the presence of surplus gamma chains in fibrinogen-producing cells is due to the unequal degradation rate of fibrinogen chains. These results indicate that the ubiquitin-proteasome pathway may be a major system for the degradation of unassembled fibrinogen chains.

An innate view of human pregnancy

Our understanding of the immunology of pregnancy has been dominated by the fetal allograft model and by changes in the maternal-specific immune system. Here, Gavin Sacks and colleagues draw attention to substantial and contrasting changes in the maternal innate system and hypothesize that its function and that of monocytes in particular, has a central role in the maternal-fetal relationship.

Reducing the length of stay after kidney transplantation--the intensive outpatient unit

The need to reduce the costs associated with the initial hospitalization for kidney transplantation has led to the development of outpatient facilities in which patients can be seen on a daily basis. The implementation of a kidney transplant intensive outpatient unit (IOPU) is described. Prior to the opening of the IOPU, the median and mean lengths of stay after kidney transplantation in our program were 14.0 and 18.9 d, respectively. Subsequent to the opening of the IOPU, the median and mean lengths of stay after kidney transplantation have gradually decreased and are currently 5.0 and 7.5 d, respectively. The median inpatient cost of transplantation, excluding organ acquisition charges, has decreased by 54%, from $25516 to $11616. Patient satisfaction has exceeded 80%. The IOPU represents an effective means of reducing the cost associated with transplantation, without sacrificing the quality of care.

Crystal structure of a recombinant alphaEC domain from human fibrinogen-420

The crystal structure of a recombinant alphaEC domain from human fibrinogen-420 has been determined at a resolution of 2.1 A. The protein, which corresponds to the carboxyl domain of the alphaE chain, was expressed in and purified from Pichia pastoris cells. Felicitously, during crystallization an amino-terminal segment was removed, apparently by a contaminating protease, allowing the 201-residue remaining parent body to crystallize. An x-ray structure was determined by molecular replacement. The electron density was clearly defined, partly as a result of averaging made possible by there being eight molecules in the asymmetric unit related by noncrystallographic symmetry (P1 space group). Virtually all of an asparagine-linked sugar cluster is present. Comparison with structures of the beta- and gamma-chain carboxyl domains of human fibrinogen revealed that the binding cleft is essentially neutral and should not bind Gly-Pro-Arg or Gly-His-Arg peptides of the sort bound by those other domains. Nonetheless, the cleft is clearly evident, and the possibility of binding a carbohydrate ligand like sialic acid has been considered.

Association of XK and Kell blood group proteins

A disulfide bond links Kell and XK red cell membrane proteins. Kell, a type II membrane glycoprotein, carries over 20 blood group antigens, and XK, which spans the membrane 10 times, is lacking in rare individuals with the McLeod syndrome. Kell is classified in the neprilysin family of zinc endopeptidases, and XK has structural features that suggest it is a transport protein. Kell has 15 extracellular cysteines, and XK has one in its fifth extracellular loop. Five of the extracellular cysteine residues in Kell are not conserved in the other members of the neprilysin family, and based on the hypothesis that one of the nonconserved cysteines is linked to XK, cysteines 72 and 319 were mutated to serine. The single extracellular cysteine 347 of XK was also mutated. Co-expression of combinations of wild-type and mutant proteins in transfected COS-1 cells showed that Kell C72S did not form a Kell-XK complex with wild-type XK, while wild-type Kell and Kell C319S did. XK C347S was also unable to form a complex with wild-type Kell, indicating that Kell cysteine 72 is linked to XK cysteine 347. Kell C72S was transported to the cell surface, indicating that linkage to XK is not required. In addition, chemical cross-linking of red cell membranes with dithiobispropionimidate indicated that glyceraldehyde-3-phosphate dehydrogenase is a near neighbor of Kell.

Inhibitory effect of selenomethionine on the growth of three selected human tumor cell lines

Selenium supplementation has been shown for many years to work as an anticarcinogenic agent both in epidemiology and in in vitro studies. Selenium supplementation has recently been shown to decrease total cancer incidence. However, the mechanism of action of selenium as an anticarcinogenic agent has yet to be elucidated. Selenomethionine was the predominant form of selenium in the dietary supplement in the study by Clark et al. (Clark, L.C., Combs, G.F., Turnbull, W.B., Slate, E.H., Chalker, D.K., Chow, J., Davis, L.S., Glover, R.A., Graham, G.F., Gross, E.G., Krongrad, A., Lesher, J.L., Park, H.K., Sanders, B.B., Smith, C.L., Taylor, J.R. and The Nutritional Prevention of Cancer Study Group (1996) Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin: a randomized controlled trial. J. Am. Med. Assoc., 276 (24), 1957-1963) and therefore we evaluated the growth inhibitory effects of selenomethionine against human tumor cells. Selenomethionine was tested against each of three human tumor cell lines (MCF-7/S breast carcinoma, DU-145 prostate cancer cells and UACC-375 melanoma) and against normal human diploid fibroblasts. All cell lines demonstrated a dose-dependent manner of growth inhibition by selenomethionine. Selenomethionine inhibited the growth of all of the human tumor cell lines in the micromolar (microM) range (ranging from 45 to 130 microM) while growth inhibition of normal diploid fibroblasts required 1 mM selenomethionine, approximately 1000-fold higher than for the cancer cell lines. In short, normal diploid fibroblasts were less sensitive than the cancer cell lines to the growth inhibitory effects of selenomethionine. Furthermore, we show that selenomethionine administration to these cancer cell lines results in apoptotic cell death and aberrant mitoses. These results demonstrate the differential sensitivity of tumor cells and normal cells to selenomethionine.

The KEL24 and KEL14 alleles of the Kell blood group system

BACKGROUND

The Kell blood group system consists of at least 21 antigens, which may be classified into five sets of alleles and at least 10 independently expressed antigens. The molecular basis of four of the five sets of alleles has been described; point mutations in KEL leading to amino acid substitutions characterize the alleles. In this study, the point mutation associated with the remaining allele, KEL14/KEL24, was determined.

STUDY DESIGN AND METHODS

The 19 exons of KEL were amplified from genomic DNA by a polymerase chain reaction (PCR) procedure. The PCR products were sequenced. DNA sequences from unrelated KEL:14,24 and KEL:-14,24 individuals were compared to the DNA sequence of the common KEL:14,-24 phenotype.

RESULTS

DNA from the KEL:14,24 person yielded both G and C at nt 659, indicating an Arg and Pro polymorphism in amino acid residue 180 of Kell protein. DNA from the KEL:-14,24 person had a G659C mutation in exon 6, indicating an Arg180Pro substitution. The G659C change introduces an Hae III restriction enzyme site, which was used to confirm the base mutations by restriction fragment length polymorphism analysis of the PCR products.

CONCLUSION

A G659C mutation, predicting an Arg180Pro change in Kell protein, is associated with the KEL14/KEL24 allele.

Involvement of polyamines in selenomethionine induced apoptosis and mitotic alterations in human tumor cells

The efficacy of dietary selenium supplementation is currently being evaluated in intervention trials. However, the biological mechanisms underlying the cancer chemopreventive effects of selenium supplementation have yet to be elucidated. Selenium metabolism and polyamine biosynthesis are linked in their common requirement for S-adenosylmethionine. Selenomethionine was the predominant form of selenium in the dietary supplement, therefore we evaluated the anti-tumorigenic effects of selenomethionine. We found that selenomethionine inhibited tumor growth (both in A549 lung and HT29 colon cancer cells) in a dose-dependent manner. At 24 and 72 h, polyamine content of A549 and HT29 cancer cell lines was decreased at doses that inhibited 50% of normal growth. Selenomethionine treatment induced apoptosis in both cancer cell lines. Exogenous spermine administration, which replenishes intracellular polyamine levels, prevented selenomethionine induced apoptosis. Selenomethionine administration to the cancer cell lines increased the number of cells in metaphase. This cell cycle effect appeared to be reversed with the co-administration of selenomethionine and spermine. These data suggested that at least part of the anti-carcinogenic effects of selenium supplementation might be due to a depletion in polyamine levels. This depletion of polyamines leads to an induction in apoptosis and perturbations in the cell cycle.

The role of the neonatal family care specialist

The role of neonatal family care specialist was developed to meet the demands of an ever-changing health service. Families are empowered and encouraged to take control by the provision of clear, concise information. Audit and evaluation are vital in assessing the effectiveness of the new role in order to maintain a high standard of appropriate care.

Epithelial ovarian cancer: influence of polymorphism at the glutathione S-transferase GSTM1 and GSTT1 loci on p53 expression

The importance of polymorphism in the glutathione S-transferase GSTM1, GSTT1 and, cytochrome P450, CYP2D6 loci in the pathogenesis of epithelial ovarian cancer has been assessed in two studies; firstly, a case-control study designed to determine the influence of these genes on susceptibility to this cancer, and secondly, the putative role of these genes in the protection of host cell DNA has been studied by comparing p53 expression in patients with different GSTM1, GSTT1 and CYP2D6 genotypes. The frequencies of GSTM1, GSTT1 and CYP2D6 genotypes in 84 cases and 325 controls were not different. Immunohistochemistry was used to detect p53 expression in 63 of these tumours. Expression was found in 23 tumours. Of the patients demonstrating immunopositivity, 20 (87%) were GSTM1 null. The frequency distributions of GSTM1 genotypes in p53-positive and -negative samples were significantly different (P = 0.002) and those for GSTT1 genotypes approached significance (exact P = 0.057). The proportion of patients with both GSTM1 null and GSTT1 null was also significantly greater in the immunopositive (4/22) than in the immunonegative group (1/40) (P = 0.0493). Single-strand conformational polymorphism (SSCP) analysis was used to detect mutations in the 23 tumour samples demonstrating p53 positivity. A shift in electrophoretic mobility of amplified fragments was found in 11 patients (exons 5, 6, 7 and 8) and these exons were sequenced. In eight samples a mutation was found. No SCCP variants were identified in the other 12 immunopositive patients. Sequencing of exons 4-9 of p53 from these tumours resulted in the detection of mutations in two patients (exons 5 and 7). Thus, in 23 patients who demonstrated immunopositivity, p53 mutations were found in nine patients with GSTM1 null (90.0%). In the 13 patients in whom no mutations were identified, 11 were GSTM1 null (84.6%). The data show that overexpression of p53 is associated with the GSTM1 null genotype. We propose the data are compatible with the view that GSTM1 and GSTT1 are critical in the detoxification of the products of oxidative stress produced during the repair of the ovarian epithelium. Thus, failure to detoxify products of this stress may result in damage to various genes in the host cell, including to p53, resulting in persistent expression of mutant protein. In other patients, oxidative stress effects damage to various genes, but not including p53, resulting in overexpression of wild-type p53.

Fibrinogen assembly and secretion. Role of intrachain disulfide loops

Human fibrinogen is a homodimer composed of three different (Aalpha, Bbeta, gamma) polypeptide chains. The chains are linked by 29 inter- and intrachain disulfide bonds. Each half-molecule has 6 intrachain disulfide bonds, which form loops in the carboxyl-terminal region of each of the chains. Aalpha chain has one disufide loop (Cys442-Cys472), Bbeta has three (Cys201-Cys286, Cys211-Cys240, and Cys394-Cys407), and gamma has two loops (Cys153-Cys182 and Cys326-Cys339). The intrachain loops are conserved in fibrinogens of different species. We changed, by site-directed mutagenesis, the cysteines, which form the intrachain loops, to serine or alanine. Fibrinogen chain assembly and secretion was determined in transiently transfected COS cells expressing two normal and a mutant fibrinogen chain. In the Bbeta and gamma chains, disruption of the disulfide loops closest to the "coiled-coil" region (CysBbeta211-Cys240, CysBbeta201-Cys286, and Cysgamma153-Cys182) abolished chain assembly and secretion, indicating that the disulfide loops closest to the coiled-coil region are essential for chain assembly. By contrast, preventing formation of the disulfide loops, which are toward the carboxyl termini of each of the chains, had different effects. Disruption of the single Aalpha disulfide loop had no effect, as did disruption of BbetaCys394-Cys407. However, disruption of Cysgamma326-Cys339, which is similar in size and location to CysBbeta394-Cys407, allowed chain assembly to occur, but the assembled chains were not secreted.