Polymorphism in oestrogen response element associated with variation in plasma angiotensinogen concentrations in healthy pregnant women

OBJECTIVE

To investigate the hypothesis that the genotype at nucleotide A(-20)C in the 5' flanking region of the angiotensinogen gene, which lies within a sequence with high homology to an oestrogen response element, affects plasma angiotensinogen levels in pregnancy.

DESIGN

Prospective observational study

METHODS

Seventy-two healthy pregnant women were recruited in the second half of pregnancy from hospital and primary care antenatal clinics in Nottingham, UK. Plasma angiotensinogen concentrations were measured by radioimmunoassay of angiotensin I generated from endogenous angiotensinogen in the presence of excess human renin. DNA was extracted from peripheral venous blood, and angiotensinogen genotype determined at A(-20)C, G(-6)A and Met235Thr. Associations between genotype and plasma angiotensinogen concentration were assessed by analysis of variance.

RESULTS

Women homozygous for the -20C allele had the lowest mean plasma angiotensinogen concentration of 1.7 +/- 0.3micromol/l. Women homozygous for -20A had significantly higher plasma angiotensinogen concentrations (2.6 +/- 0.1 micromol/l), and intermediate levels (2.0 +/- 0.1 micromol/l) were observed in women heterozygous for A(-20)C (P = 0.002, ANOVA). The polymorphisms at nucleotide -6 and codon 235 were in almost complete linkage disequilibrium, and nucleotide -20C was found only in a subset of -6A/235Thr alleles. Conclusion The low plasma angiotensinogen levels associated with the -20C/-6A/235Thr haplotype in pregnant women contrast with the high concentrations associated with the 235Thr allele in the non-pregnant state. A possible explanation lies in the presence of a motif with high homology to an oestrogen response element between the TATA box and transcription initiation site. Previous in vitro studies of reporter gene constructs have demonstrated thatthe A(-20)C polymorphism affects oestrogen responsiveness. The results of this study support the hypothesis that the oestrogen response element of the angiotensinogen gene is of functional importance in pregnancy, and that oestrogen responsiveness in pregnancy is influenced by the genotype at nucleotide - 20.

Achieving a credible health and safety approach to increasing seat belt use among African Americans

African American youth are 60 percent less likely than children from other racial or ethnic backgrounds to be buckled up. Seat belt use among African American males has largely remained stagnant while that for other groups has increased. Overall, African Americans buckle up less often than other racial or ethnic populations. Seat belt use is a preventive health care action within public health. Clearly, a credible health and safety message is not being communicated effectively to African American communities. This paper proposes a number of possible solutions, including: recognition of the role that health care providers play in shaping patient or consumer attitudes and subsequent behavior in terms of prevention of disease and injury, educating physicians and health care providers to routinely recommend seat belt use especially for children, culturally appropriate educational safety programs, an improved relationship between law enforcement and communities, and zero tolerance for nonuse of seat belts.

Vascular endothelial growth factor stimulates dephosphorylation of the catenins p120 and p100 in endothelial cells

Vascular endothelial growth factor (VEGF) is an endothelium-specific mitogen that induces angiogenesis and increases vascular permeability. These processes involve regulation of cell-cell adhesion, but molecular mechanisms have yet to be fully established. p120, also termed p120(ctn), and its variant p100 are catenins which associate with cadherins and localize to adherens junctions. VEGF was reported to stimulate tyrosine phosphorylation of catenins in endothelial cells. In contrast, we have found that VEGF potently stimulated a rapid and dose-dependent decrease in serine/threonine phosphorylation of p120 and p100. VEGF acted via VEGF receptor 2 to achieve this effect which was independent of activation of the extracellular-signal-regulated kinase pathway. Histamine and activators of protein kinase C had a very similar effect to that of VEGF on phosphorylation of p120 and p100, suggesting that these diverse stimuli may converge on a common signalling element regulating p120/p100 serine/threonine phosphorylation. These data raise the possibility that the dephosphorylation of p120 and p100 triggered by VEGF may contribute to mechanisms regulating permeability and/or motility through modulation of cadherin adhesiveness.

A new information resource for palliative care professionals

A challenge that the palliative care community shares with other professions is that of networking the knowledge it generates - not only among persons within the profession, but also to practitioners in other specialties, for example, primary care. While face-to-face communication and print media continue to serve well, a new means of disseminating palliative care knowledge and expertise became available in 1999.

Effect of a comprehensive infection control program on the incidence of infections in long-term care facilities

BACKGROUND

Control of infection within the long-term care facility is a daunting problem. Elderly patients are at high risk for contracting infection because of reduced innate immunity, malnutrition, and the presence of chronic medical conditions. This small study tested the effect of developing and implementing a comprehensive preventive infection control program in the long-term care setting and examined the resultant incidence of infections.

METHODS

Eight private, freestanding, long-term care facilities in urban and suburban settings were selected for the study. The 4 test sites had a total of 443 beds; there were 447 beds in 4 matched control sites. Data on infection rates were accrued in both preintervention and intervention years. The control homes maintained their existing infection control policies and procedures. The test homes were provided with an infection control educational program and replaced all currently used germicidal products with single-branded products for a 12-month period. A criteria-based standardized infection control surveillance system was used to monitor and report infections in all facilities.

RESULTS

In the preintervention year, the test sites experienced 743 infections (incidence density rate, 6.33) and the control homes experienced 614 infections (incidence density rate, 3.39). In the intervention year, the test homes reported 621 infections, a decrease of 122 infections (incidence density rate, 4.15); in the control homes, the number of infections increased slightly, to 626 (incidence density rate, 3.15). The greatest reduction in infections in the test homes was in upper respiratory infections (P =.06).

CONCLUSIONS

This study provides additional evidence that a comprehensive infection control program that includes handwashing and environmental cleaning and disinfecting may help reduce infections among the elderly residing in long-term care settings.

Effect of glucagon on carbohydrate-mediated secretion of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (7-36 amide) (GLP-1)

BACKGROUND

The insulinotropic hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (7-36 amide) (GLP-1), regulate insulin secretion to nutrient intake and constitute the endocrine arm of the entero-insular axis. Glucagon has been implicated in the pathophysiology of conditions characterised by abnormal glucose tolerance such as obesity and diabetes mellitus although its effect on the entero-insular axis is not fully understood. Materials and methods We investigated the effect of exogenous glucagon on the entero-insular axis and its relation to gastric emptying in six healthy men aged [mean (+/-S.E.M. )] 23.6 (0.9) years with a body mass index of 24.0 (1.5) kg/m(2). Plasma glucose, GIP, GLP-1, insulin and paracetamol concentrations were measured before and after a 100 g oral carhohydrate load containing 1.5 g of paracetamol for 6 h during intravenous infusion of either glucagon or saline.

RESULTS

When compared to the saline infusion, peak and integrated insulin and glucose concentrations were higher (p<0.05) following glucagon infusion. After 60 min paracetamol concentrations were lower (p<0.05) following glucagon infusion. Integrated responses for GIP and GLP-1 were markedly reduced following glucagon infusion.

CONCLUSIONS

Exogenous glucagon in addition to its well-documented action of increasing glucose and insulin concentrations and delaying gastric emptying also markedly reduces GIP and GLP-1 secretion. The inhibition of GLP-1 soon after commencement of glucagon infusion supports a direct effect of glucagon on intestinal L-cells. We speculate that the marked inhibition of postprandial GLP-1 secretion by glucagon may be of importance in the pathogenesis of relative insulinopenia in Type 2 diabetes and in the development of reduced satiety in obesity and diabetes.

Promoting evidence-based practice: managing change in the assessment of pressure damage risk

AIMS

This study set out to facilitate the development of evidence-based practice in the assessment of pressure damage risk to patients within a large acute hospital.

BACKGROUND

The importance of nursing practice being based on the best available evidence is emphasized in recent health policy. Meeting this objective is not easy as both individual and organizational factors create barriers to the implementation of research findings and the achievement of change.

METHODS

The study was based on an action research model. It comprised three stages: a review of the research evidence; a survey of qualified nurses' knowledge of risk assessment of pressure damage and an audit of record keeping, and a multifaceted approach to achieving change in which researchers, managers, practitioners and clinical nurse specialists worked together collaboratively.

FINDINGS

The findings from the survey and audit indicated a shortfall in nurses' knowledge of risk assessment of pressure damage and in their record keeping. The researchers, with the help of the clinical nurse specialist, built upon these findings by assisting practitioners and managers to take ownership of the need to base practice on the appropriate evidence.

CONCLUSIONS

Achieving evidence-based practice is a complex undertaking that requires the development of an evaluative culture and a commitment by practitioners and managers to change practice. Researchers can play a valuable role in facilitating this process.

Evaluation of polymorphisms in the presenilin-1 gene and the butyrylcholinesterase gene as risk factors in sporadic Alzheimer's disease

The E4 allele of the apolipoprotein E gene (APOE) is a major risk factor for late-onset Alzheimer's disease (LOAD) but is neither necessary nor sufficient to cause the disease. In this study, we investigated polymorphisms in the presenilin-1 (PS-1), and butyrylcholinesterase (BChE) genes, which have been implicated as risk factors for LOAD. Our data-set comprised 177 AD and 118 control patients, all of whom had been histopathologically confirmed following autopsy. We have tested homozygosity for the PS-1 allele 1 and possession of the BChE-K variant in association with APOE epsilon4 as risk factors in LOAD. Our findings support an association between the PS-1 polymorphism and LOAD, finding homozygosity for allele 1 associated with an approximately two-fold increased risk. Our data also show that in subjects greater than 75 years of age possession of both BChE-K and APOE-epsilon4 alleles is associated with an increased risk of LOAD, whilst the risk associated with APOE-epsilon4 allele alone is not significant.

Proinsulin and insulin responses to a mixed meal in hypertriglyceridaemic men

AIM

To investigate the contribution of proinsulin to the "hyperinsulinaemia" of hypertriglyceridaemia.

METHODS

Plasma glucose, triglyceride, immunoreactive insulin, and intact proinsulin concentrations were measured before and after a mixed meal in 11 hypertriglyceridaemic men and six healthy normotriglyceridaemic male controls.

RESULTS

Hypertriglyceridaemic subjects had greater fasting (101 v 50 pmol/l) and integrated (139 v 81 x 0(-3) pmol/l/h) insulin concentrations than controls. Fasting and integrated glucose and proinsulin concentrations were similar in the two groups.

CONCLUSIONS

Proinsulin does not contribute to the hyperinsulinaemia observed in hypertriglyceridaemic subjects and is therefore unlikely to contribute to the increased cardiovascular risk associated with hypertriglyceridaemia.

Angiotensin-converting enzyme insertion-deletion polymorphism in normotensive and pre-eclamptic pregnancies

OBJECTIVE

To investigate the hypothesis that pre-eclampsia is associated with a common insertion-deletion polymorphism in the angiotensin-converting enzyme gene.

DESIGN

Seventy-two women with pre-eclampsia and 83 normotensive pregnant women participated in the study. Pre-eclampsia was defined as a blood pressure exceeding 140/90 mm Hg in a previously normotensive woman, associated with proteinuria in excess of 300 mg/l in a 24 h collection. Samples for fetal genotyping were available from 66 pregnancies complicated by pre-eclampsia and 79 normotensive pregnancies.

METHODS

Maternal and fetal samples were genotyped at the insertion-deletion (I-D) polymorphism in intron 16 of the angiotensin-converting enzyme gene by the polymerase chain reaction followed by agarose electrophoresis.

RESULTS

Neither the I-D genotype distributions nor the allele frequencies differed significantly between pre-eclamptic and normotensive pregnancies in maternal or fetal samples (phi2 <0.3, not significant). The odds ratio for pre-eclampsia in women with the DD genotype, compared with the ID and II genotype, was 1.09 (95% confidence interval 0.55-2.16). The odds ratio associated with the DD genotype in the fetus was 1.14 (0.56-2.32).

CONCLUSION

This study has found no evidence that the insertion-deletion polymorphism in the angiotensin-converting enzyme gene is associated with pre-eclampsia.

Inhibition of carbohydrate-mediated glucagon-like peptide-1 (7-36)amide secretion by circulating non-esterified fatty acids

Two studies were performed to assess the entero-insular axis in simple obesity and the possible effect of variations in the level of circulating non-esterified fatty acids (NEFA) on one of the components of the entero-insular axis, glucagon-like peptide-1 [(7-36) amide]. In the first study, we compared the entero-pancreatic hormone response to oral carbohydrate in obese and lean women. Obese subjects demonstrated hyperinsulinaemia and impaired glucose tolerance but this was not associated with an increased secretion of either glucose-dependent insulinotropic polypeptide or glucagon-like peptide-1 (GLP-1). These findings therefore provide no support for the hypothesis that overactivity of the entero-insular axis contributes to the hyperinsulinaemia seen in obesity. Indeed, the plasma GLP-1 response to carbohydrate was markedly attenuated in obese subjects, confirming previous observations. In the second study, in which carbohydrate-stimulated GLP-1 responses were again evaluated in obese and lean women, circulating NEFA levels were modulated using either heparin (to increase serum NEFA) or acipimox (to reduce serum NEFA). Treatment with acipimox resulted in complete suppression of NEFA levels and in a markedly higher GLP-1 response than the response to carbohydrate alone or to carbohydrate plus heparin. We suggest that higher fasting and postprandial NEFA levels in obesity may tonically inhibit nutrient-mediated GLP-1 secretion, and that this results in attenuation of the GLP-1 response to carbohydrate. However, although serum NEFA levels post-acipimox were similarly suppressed in both lean and obese subjects, the GLP-1 response was again significantly lower in obese subjects, suggesting the possibility of an intrinsic defect of GLP-1 secretion in obesity. The reduction of GLP-1 levels in obesity may be important both in relation to its insulinotropic effect and to its postulated role as a satiety factor.

Maternal and fetal angiotensinogen gene allele sharing in pre-eclampsia

OBJECTIVE

To compare the angiotensinogen genotypes in normotensive and pre-eclamptic pregnancies in maternal and fetal samples.

DESIGN

Prospective observational study.

SETTING

University Hospital, Queen's Medical Centre, Nottingham.

POPULATION

Forty-three women with pre-eclampsia and 84 normotensive pregnant women. Fetal samples were available for genotyping from 96% of the pregnancies.

METHODS

Maternal and fetal DNA was genotyped at angiotensinogen codon 235 and at a dinucleotide repeat polymorphism in the 3' flanking region of the gene. Angiotensinogen and renin concentrations were measured in maternal plasma by radioimmunoassay.

RESULTS

In contrast to earlier studies, no association was demonstrated between the angiotensinogen 235 Thr variant and pre-eclampsia. Normotensive pregnant women homozygous for this variant had significantly lower plasma angiotensinogen concentrations (median 2.2 ng AI/mL; IQR 1.8-3.0) than women homozygous for the 235 Met allele (3.6 ng AI/mL; IQR 2.5-4.1; P = 0.04). In pre-eclamptic pregnancies, 79% (11/14) of mothers heterozygous for the dinucleotide repeat allele designated A9 transmitted this allele to the fetus, more frequently than would be expected by chance (P = 0.02). The A9 allele was associated with low plasma angiotensinogen concentrations (P = 0.001) and high renin concentrations (P = 0.02) in normotensive women.

CONCLUSIONS

There is no evidence that the angiotensinogen 235 Thr allele is associated with pre-eclampsia in the Nottingham population. The angiotensinogen 235 Thr allele is associated with low plasma angiotensinogen concentrations in normotensive pregnant women, in contrast to the high levels associated with this variant in non-pregnant women, suggesting that regulation of angiotensinogen expression in normal pregnancy may differ significantly from that in the non-pregnant state. There is preliminary evidence that maternal-fetal transmission of an angiotensinogen allele associated with low plasma angiotensinogen concentrations is associated with pre-eclampsia. Impaired generation of angiotensin II at the maternal-fetal interface may be a factor in the pathogenesis of pre-eclampsia.

The effect of circulating non-esterified fatty acids on the entero-insular axis

BACKGROUND

Circulating non-esterified fatty acids (NEFAs) have been causally associated with impairment of glucose metabolism, although their effect on the entero-insular axis, either in obesity or health, is unknown.

MATERIALS AND METHODS

Glucose, insulin, glucagon-like peptide-1 (7-36 amide) (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) responses to 100 g of carbohydrate in 400 mL water were evaluated during simultaneous modulation of circulating non-esterified fatty acids (NEFAs). A total of 10,000 units of heparin (to increase serum NEFAs) and 500 mg of acipimox (2 h before oral carbohydrate ingestion to reduce serum NEFAs) were administered to seven obese [mean +/- SEM: age 40 +/- 3.7 years; body mass index (BMI) 38.9 +/- 2.1 kg m-2] and seven lean (age 39.6 +/- 3.6 years; BMI 22.4 +/- 0.4 kg m-2) women.

RESULTS

Higher fasting levels and post-heparin total integrated NEFAs (P < 0.05) and glycerol (P < 0.05) responses were seen in the obese than in the lean group. Incremental integrated GLP-1 responses to oral carbohydrate post-heparin in lean (P < 0.01) and obese (P < 0.05) subjects were significantly lower than after acipimox. Total integrated GIP (P < 0.05) and glucose (P < 0.01) responses were higher post heparin than after acipimox in obese subjects only.

CONCLUSION

The inverse relationship in GIP and GLP-1 responses in the obese group after modulation of NEFAs indicates that reciprocal changes between these two hormones may exist to ensure constancy of B-cell stimulation. Our results suggest that in obese subjects compensatory secretion of GIP was incomplete and could not prevent impairment in glucose tolerance after heparin-induced rise in NEFAs. These results may be important in understanding the role of the insulinotropic hormones in carbohydrate metabolism characterized by high NEFA levels such as obesity and diabetes mellitus.

Hematology and chemistry reference values for free-ranging harbor seals (Phoca vitulina) and the effects of hemolysis on chemistry values of captive harbor seals

Most reported laboratory reference values for harbor seals (Phoca vitulina) are derived from captive seals, or stranded seals that have recovered from disease in marine mammal centers. This study established hematology and serum chemistry reference values for free-ranging harbor seals, using methods and that are current and readily available, and determined the effects of hemolysis on serum chemistry values of captive harbor seals. Blood samples were collected for hematologic and serum chemistry measurements from 14 clinically normal, adult male and female harbor seals and two juvenile harbor seals (approximate age 6 mo) captured in saltwater sloughs and estuaries near Moss Landing, California, USA. Values for amylase, globulin, and differential leukocyte count, not previously reported, were determined. In general, hematology and chemistry values in adults were similar to those reported for free-ranging and captive harbor seals, except for glucose, urea nitrogen, and lactate dehydrogenase (LDH) values, which were higher than those reported previously. Red blood cell counts in the two juveniles were higher than in adults and in young harbor seals studied previously. To determine the effects of hemolysis on serum chemistry values, two intensities of hemolysis were generated experimentally in blood collected from 11 harbor seals recovering from injuries or stranding at the Marine Mammal Center (Sausalito, California 94965, USA). Moderate hemolysis (++, 1 g/L hemoglobin, red-tinged) significantly increased LDH activity, whereas severe hemolysis ( , 2 g/L hemoglobin, cherry red) significantly increased total protein, albumin, calculated globulin, LDH, and total bilirubin and significantly decreased creatinine. The effects of hemolysis must be considered when chemistry results of harbor seals are interpreted.

Arthritis self-management program variations: three studies

OBJECTIVES

1) Determine strengths and weaknesses of the Arthritis Self-Management Program (ASMP). 2) Compare 3- and 6-week ASMP. 3) Evaluate 1.5-hour arthritis program.

METHODS

Study 1: Qualitative methods incorporating incomplete block design. Study 2: Comparison of 3- and 6-week outcomes. Study 3: Pretest/posttest comparison.

RESULTS

Study 1: Pain management, exercise, and sharing ranked as the most useful aspects of the ASMP. Nutrition, medications, and making decisions about nontraditional treatments ranked least useful. Study 2: Six-week ASMP subjects improved pain, health distress, illness impact, exercise, cognitive pain management, self-efficacy, and reduced visits to physicians (P < 0.05). Three-week subjects improved health distress, cognitive pain management, and self-efficacy (P < 0.05). Study 3: Improved knowledge, self-efficacy, and pain (P < 0.05).

CONCLUSIONS

The traditional 6-week ASMP is more effective than a 3-week version. A 1.5-hour community program is effective in increasing knowledge, self-efficacy, and contact with the Arthritis Foundation.

Evidence-based care: can we overcome the barriers?

Evidence-based care has become the new mantra within the NHS, despite the fact that the concept of applying research to practice has been promoted for several decades. However, literature on the subject suggests that formidable obstacles remain to the integration of research into care delivery. This article describes a study which used Funk et al's (1991a,b) Barriers Scale with a population of nurses in a large teaching hospital in the UK. This scale was specifically developed to identify barriers to the introduction of research into practice, and modified for a UK context. The results suggest that a complex array of barriers exist but that foremost among these is the nature of the organizations within which nurses work. Comparisons are made with data from the USA, and the need to create time for nurses to implement change, and to empower them to do so, is stressed.

The ageing entero-insular axis

Ageing is one of the major risk factors for glucose intolerance including impaired glucose tolerance and Type II (non-insulin-dependent) diabetes mellitus. Reduced insulin secretion has been described as part of normal ageing although there is no information on age-related changes in the secretion of the major insulinotropic hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (7-36 amide) (GLP-1). We assessed the entero-insular axis in 6 young premenopausal and 6 older postmenopausal women following treatment with oral carbohydrate. Insulin and glucose integrated responses were similar in the younger and older groups. Total integrated responses for GIP and GLP-1 were considerably greater in the older subjects. A positive correlation between age and total integrated responses for glucose (r = 0.65; p < 0.02) as well as GLP-1 (r = 0.85; p < 0.001) was seen. We hypothesise that an age-related impairment of insulin secretion to insulinotropic hormones, GIP and GLP-1, contributes to a reduction in glucose tolerance in this age group. The pronounced compensatory increase in postprandial secretion of GIP and GLP-1 provides further evidence not only for the negative feedback relation between incretin and insulin secretion but also for the importance of the entero-insular axis in the regulation of insulin secretion.

Altered postprandial hormone and metabolic responses in a simulated shift work environment

The circadian rhythms of most night shift workers do not adapt fully to the imposed behavioural schedule, and this factor is considered to be responsible for many of the reported health problems. One way in which such disturbances might be mediated is through inappropriate hormonal and metabolic responses to meals, on the night shift. Twelve healthy subjects (four males and eight females) were studied on three occasions at the same clock time (1330 h), but at different body clock times, after consuming test meals, first in their normal environment, secondly after a forced 9 h phase advance (body clock time approximately 2230 h) and then again 2 days later in the normal environment. They were given a low-fat pre-meal at 0800 h, then a test meal at 1330 h with blood sampling for the following 9 h. Parameters measured included plasma glucose, non-esterified fatty acids (NEFAs), triacylglycerol (TAG), insulin, C-peptide, proinsulin and glucose-dependent insulinotropic polypeptide, and urinary 6-sulphatoxymelatonin. In contrast with a previous study with a high-fat pre-meal, postprandial glucose and insulin responses were not affected by the phase shift. However, basal plasma NEFAs were lower immediately after the phase shift (P < 0.05). Incremental (difference from basal) TAG responses were significantly higher (P < 0.05) immediately after the phase shift compared with before. Two-day post-phase shift responses showed partial reversion to baseline values. This study suggests that it takes at least 2 days to adapt to eating meals on a simulated night shift, and that the nutritional content of the pre-meals consumed can have a marked effect on postprandial responses during a simulated phase shift. Such findings may provide a partial explanation for the increased occurrence of cardiovascular disease reported in shift workers.

Distortion of maternal-fetal angiotensin II type 1 receptor allele transmission in pre-eclampsia

OBJECTIVE

To investigate the fetal angiotensin II type 1 receptor genotype in pre-eclampsia.

DESIGN

Case-control study.

POPULATION

Forty-one maternal-fetal pairs from pre-eclamptic pregnancies and 80 maternal-fetal pairs from normotensive pregnancies.

METHODS

Maternal and fetal DNA was genotyped at three diallelic polymorphisms, at nucleotides 573, 1062, and 1166, in the coding exon of the angiotensin II type 1 receptor gene, and at a dinucleotide repeat polymorphism in its 3' flanking region.

RESULTS

Allele and genotype frequencies at the four polymorphic regions investigated did not differ between pre-eclamptic and normotensive groups, in either fetal or maternal samples. Mothers heterozygous for the dinucleotide repeat allele designated A4 transmitted this allele to the fetus in 15 of 18 informative pre-eclamptic pregnancies and in eight of 26 normotensive pregnancies. This was greater than the expected probability in pre-eclamptic pregnancies (p=0.04) and less than expected in normotensive pregnancies (p<0.005). The 573T variant, which is in partial linkage disequilibrium with the A4 allele, showed a similar distortion of maternal-fetal transmission.

CONCLUSION

Angiotensin II type 1 receptor gene expression in the fetus may contribute to the aetiology of pre-eclampsia. It is unclear whether susceptibility is conferred by the fetal genotype acting alone, or by allele sharing by mother and fetus. Possible mechanisms for the effect of the angiotensin II type 1 receptor gene are suggested by the association of the 573T variant with low levels of surface receptor expression on platelets. If receptor expression is similarly genetically determined in the placenta, responsiveness to angiotensin II may be affected, with the potential to influence placentation or placental prostaglandin secretion.

Investigation of the possible associations between fluorosis, fluoride exposure, and childhood behavior problems

PURPOSE

This study investigated the potential association between fluoride exposure and behavior problems in children, as well as the prevalence of and risk factors for fluorosis.

METHODS

Children between the ages of 7 and 1 years (N = 197) were included in the study and were examined for dental fluorosis using the Modified Dean's Index. Parents of subjects completed and returned three questionnaires which investigated their children's history of exposures to fluoride, social and medical backgrounds, and behavior using the Child Behavior Checklist (CBCL).

RESULTS

Sixty-nine percent of the study participants demonstrated fluorosis with very mild fluorosis being the most common (39%), while 13% demonstrated moderate to severe fluorosis. Using a summation of the Modified Dean's index (Sum of 8), we divided the children into high fluorosis (HF) and low fluorosis (LF) groups. These groups were compared to each other with respect to fluoride exposures and behavior.

CONCLUSION

Although there was no association between the fluoride exposures in aggregate and fluorosis, there was a significant association between supplemental fluoride exposure from ages 0-3 years and fluorosis. There was no association between behavior problems and dental fluorosis in this population.