Acetabular cup migration. Prediction of aseptic loosening

We measured the proximal migration of 265 acetabular cups over seven years and correlated the findings with clinical outcome and acetabular revision for aseptic loosening. Cups which eventually became aseptically loose were shown to migrate more rapidly than successful cups. The average proximal migration at two years postoperatively for four groups of cups showed a monotonic relationship to the acetabular revision rate for aseptic loosening at 6.5 years. We conclude that acetabular cups which develop aseptic loosening as evidenced by pain, revision or screw fracture show increased proximal migration by one year, and that the 'migration rate' at two years can be used to predict the acetabular revision rate from aseptic loosening at 6.5 years.

Glucose intolerance and impairment of insulin secretion in relation to vitamin D deficiency in east London Asians

Vitamin D deficiency reduces insulin secretion and still occurs in East London Asians in whom the prevalence of diabetes mellitus is at least four times that of Caucasians. Vitamin D status was assessed in 44 of 65 non-diabetic subjects 'at risk' of diabetes (spot blood glucose level >6.0 mmol/l <2 h post cibum, or>4.6 mmol/l >2 h post cibum on two separate occasions) and in 15 of 60 age and sex-matched 'low-risk' control subjects who attended for oral glucose tolerance test (OGTT) after screening of 877 omnivorous subjects not known to have diabetes. It was found that 95% of at-risk and 80% of low-risk subjects were vitamin D deficient (serum 25-hydroxy-vitamin D <11 ng/ml). Diabetes was present in 16, impaired glucose tolerance in 12 and normoglycaemia in 19 at-risk subjects, imparied glucose tolerance in 2, and normoglycaemia in 13 low-risk subjects. Correlation of 30-min OGTT blood glucose, specific insulin and C-peptide levels with 25-hydroxy-vitamin D concentrations in 44 at-risk subjects were -0.31 (p=0.04), 0.59 (p=0.0001) and 0.44 (p=0.006). In 15 'not-at-risk' subjects 30-min OGTT specific insulin and C-peptide levels correlated with 25-hydroxy-vitamin D, r=0.39 (p=0.04) and 0.16 (p=0.43), respectively. Serum alkaline phosphatase concentration was higher in at-risk than not-at-risk subjects (59.6 vs 46.5 IU/l, p=0.012); corrected calcium concentrations were comparable (2.38 vs 2.39 mmol/l, p=0.7). Following treatment with 100,000 IU vitamin D by i.m. injection, specific insulin, C-peptide [30 min on OGTT] and 25-hydroxy-vitamin D concentrations had risen 8-12 weeks later [mean +/- DS] from 57 +/- 62 to 96.2 +/- 82.4 mU/l [p=0.0017], 1.0 +/- 0.4 to 1.7 +/- 0.8 pmol/ml [p=0.001] and 3.6 +/- 1.8 to 13.5 +/- 7.4 ng/ml [p=0.0001], (but not to low-risk group values of 179 +/- mU/l, 2.7 +/- 1.14 pmol/ml and 8.16 +/- 6.4 ng/ml), respectively. Both total serum alkaline phosphatase and corrected calcium concentrations rose following vitamin D treatment in the at-risk subjects by 11.1 +/- 8.22 (from 44 to 55 IU/l) and 0.15 +/- 0.18, (2.43 to 2.57 mmol/l), respectively (p=0.004). Abnormal glucose tolerance was unchanged by vitamin D treatment. The value of early and sustained repletion with vitamin D in diabetes prophylaxis should be examined in communities where vitamin D depletion is common.

Haemodynamic and metabolic effects in diabetic ketoacidosis in rats of treatment with sodium bicarbonate or a mixture of sodium bicarbonate and sodium carbonate

To examine factors determining the haemodynamic and metabolic responses to treatment of diabetic ketoacidosis with alkali, groups of anaesthetised and ventilated rats with either diabetic ketoacidosis (mean arterial pH 6.86-6.96, mean arterial blood pressure 63-67 mm Hg) or hypovolaemic shock due to blood withdrawal (mean pHa 7.25-7.27, mean arterial blood pressure 36-41 mm Hg) were treated with sodium chloride ('saline'), sodium bicarbonate or 'Carbicarb' (equimolar bicarbonate plus carbonate). In the diabetic ketoacidosis series, treatment with either alkali resulted in deterioration of mean arterial blood pressure and substantial elevation of blood lactate, despite a significant rise in myocardial intracellular pH determined by 31P-magnetic resonance spectroscopy. These effects were accompanied by falling trends in the ratios of myocardial phosphocreatine and ATP to inorganic phosphate. Erythrocyte 2,3-bisphosphoglycerate was virtually absent in animals with diabetic ketoacidosis of this severity and duration. In contrast, in shock due to blood withdrawal, infusion of saline or either alkali was accompanied by a transient elevation of mean arterial blood pressure and no significant change in the already elevated blood lactate; erythrocyte 2,3-bisphosphoglycerate was normal in these animals. The effect of alkalinization in rats with severe diabetic ketoacidosis was consistent with myocardial hypoxia, due to the combination of very low initial erythrocyte 2,3-bisphosphoglycerate, alkali-exacerbated left shift of the haemoglobin-oxygen dissociation curve and artificial ventilation. No evidence was found for any beneficial effect of 'Carbicarb' in either series of animals; 'Carbicarb' and sodium bicarbonate could be deleterious in metabolic acidosis of more than short duration.

EMD 57033 enhances arrhythmias associated with increased wall-stress in the working rat heart

1. EMD 57033 produces a positive inotropic effect by increasing the sensitivity of cardiac muscle myofilaments to calcium. Since the elevation in intracellular calcium produced by conventional inotropic compounds is thought to be arrhythmogenic, it is hoped that compounds such as EMD 57033 may increase cardiac output without exacerbating arrhythmias in patients with cardiac failure. This is the first study to examine whether EMD 57033 influences the susceptibility of the heart to ventricular arrhythmias. 2. We used the isolated working rat heart to investigate the effect of EMD 57033 on wall-stress-induced ventricular arrhythmia. Arrhythmias were induced by increases in ventricular afterload, and the effect of 2 mumol/l EMD 57033 on ventricular arrhythmias was investigated. The effect of 2 mumol/l EMD 57033 on contractility and arrhythmias was also assessed in the presence of different levels of perfusate calcium. 3. EMD 57033 was positively inotropic in the working rat heart, but it also produced a reversible increase in wall-stress-induced ventricular arrhythmia. The incidence of both ventricular ectopics and complex arrhythmias such as ventricular tachycardia were significantly increased by EMD 57033. Arrhythmias increased progressively as the level of perfusate calcium was raised within the physiological range. 4. The mechanism by which EMD 57033 increases wall-stress-induced arrhythmia is unclear, but it seems unlikely to be directly due to elevation of intracellular calcium. Further studies of the arrhythmogenic profile of this novel compound are required in a variety of models to assess its suitability and safety as a potentially therapeutic compound in heart failure.

Cytomegalovirus colitis in AIDS: CT features

OBJECTIVE

The purpose of this study was to determine the CT features of cytomegalovirus colitis in patients with AIDS.

MATERIALS AND METHODS

Abdominal CT scans of 24 patients with biopsy-proved cytomegalovirus colitis (colonoscopy, n = 14; sigmoidoscopy, n = 8; surgery, n = 2) were jointly reviewed by two observers. Patients were men 26-68 years old (mean age, 39 years; SD, 9 years) with CD4 counts of 3-129 mm3 (mean, 32 mm3; SD, 34 mm3). The mean interval between CT and biopsy was 6 days (range, 0-20 days; SD, 6 days). Scans were assessed for colonic wall thickening (> or = 4 mm), ulceration, mural edema, pericolonic stranding, ascites, lymphadenopathy, and thickening of the small-bowel wall. Mural involvement was recorded as asymmetric or circumferential. Disease location was recorded as ascending colon, transverse colon, descending colon, rectosigmoid colon, or pancolonic.

RESULTS

Colonic wall thickening of 8 to 33 mm (mean, 15 mm; SD, 6 mm) was seen in 22 patients. One patient had pancolonic involvement. The ascending colon was involved in 13, the transverse colon in five, the descending colon in 10, and the rectosigmoid colon in 16. Circumferential colonic thickening was seen in 17 patients. Deep mural ulceration was seen in 15 patients, mural edema in 15, pericolonic stranding in 23, ascites in 10, lymphadenopathy in four, and small-bowel involvement in 10. Two patients had appendicitis. Three patients had perforations (two rectal, one cecal). One patient had a giant rectal ulcer.

CONCLUSION

Although many of the CT features of cytomegalovirus colitis are nonspecific, the diagnosis should be suggested when CT shows colonic wall thickening, particularly if the thickening is associated with mural ulceration in patients with AIDS and CD4 counts of less than 200 mm3.

Use of P-wave-triggered, P-wave signal-averaged electrocardiogram to predict atrial fibrillation after coronary artery bypass surgery

Atrial fibrillation occurs commonly after coronary artery bypass surgery. However, despite numerous attempts at prediction, no accurate and generally accepted method exists to predict its occurrence. P-wave-triggered P-wave signal averaging was performed on 54 patients before coronary artery bypass surgery to evaluate the utility of this method to predict atrial fibrillation after coronary artery bypass surgery. After excluding six patients with unevaluable P-wave signal averages and three patients with postoperative arrhythmias other than atrial fibrillation, the P-wave signal averages of 45 patients were analyzed. Sixteen patients had postoperative atrial fibrillation and 29 did not. The mean P-wave duration of the filtered, signal-averaged P wave was 163 +/- 19 msec in the 16 patients with atrial fibrillation and 144 +/- 16 msec in the 29 patients without (p < 0.005). Left atrial enlargement on the surface electrocardiogram (ECG) was the only other statistically significant variable that correlated weakly with the onset of postoperative atrial fibrillation (p = 0.04). Other clinical variables such as P-wave duration in ECG lead II, left ventricular hypertrophy on ECG, age, sex, hypertension, and left ventricular ejection fraction were not significantly different between the two groups. With a cut point of 155 msec, chi-squared analysis revealed a p value of < 0.005, yielding a sensitivity of 69%, a specificity of 79%, a positive predictive value of 65%, and a negative predictive value of 82%. Signal-averaging of the P wave in patients before coronary artery bypass surgery provides a good predictor of postoperative atrial fibrillation.

Multi-laboratory comparison of eight commercially available Helicobacter pylori serology kits. Helicobacter pylori Serology Study Group

The performance of eight commercially available EIA kits in detecting antibody to Helicobacter pylori was evaluated by a panel of 17 laboratories using serum from 59 patients selected from endoscopy clinics in Belgium, Ireland, Italy, the Netherlands and Switzerland. Each laboratory received a randomly numbered set of sera and was ignorant of the culture results of the patients. The performance of the kits was assessed in terms of diagnostic accuracy compared to culture (measured by sensitivity and specificity), the inter-laboratory variability in diagnostic accuracy and the number of laboratories that experienced problems in using the kits. Grey zone results, which are routinely used to highlight the uncertain interpretation of results that lie near the cut-off point between positive and negative diagnoses, were accounted for in the analysis. Laboratories experienced practical problems in using some kits, whilst other kits were found to have high inter-laboratory variation or low diagnostic accuracy. There was no single kit that performed better on every criterion than the others. The Orion kit was a good all-round performer, whilst the Roche kit was excellent at detecting positive results, although it had a slightly raised false-positive rate.

Wall stress induced arrhythmia is enhanced by low potassium and early left ventricular hypertrophy in the working rat heart

OBJECTIVE

The aim was to investigate the effect of lowering external potassium on the sensitivity of the normal and hypertrophied rat heart to arrhythmias induced by increases in ventricular wall stress.

METHODS

The isolated working heart model was used to compare hypertrophied hearts from the spontaneously hypertensive rat (SHR) with hearts from normotensive control rats (NCR) from the Wistar and Wistar-Kyoto strains. Young animals [131.5(SEM 0.64) days] were used to ensure uncomplicated left ventricular hypertrophy. Arrhythmias were induced by 20 s increases in ventricular wall stress. The ECG was recorded and the arrhythmic response of each heart was compared during perfusion with Tyrode solutions containing [K] 6, 4.8, 3.6, and 2.4 mM.

RESULTS

Hypertrophied SHR hearts showed a significantly greater arrhythmic response than control hearts at all levels of afterload increase when perfused with [K] 3.6 and 2.4 mM (t test P < 0.05 and P < 0.01). Both the number and complexity of arrhythmias were increased in the SHR hearts; ventricular tachycardia occurred in 10/12 compared with 4/12 control hearts whereas ventricular fibrillation occurred in 5/12 hearts but in none of the control hearts.

CONCLUSIONS

At higher levels of [K] the sensitivity of SHR and normal hearts to wall stress induced arrhythmias is similar. However, as [K] is lowered to 3.6 mM or below, hypertrophied hearts show a greatly enhanced response to increases in ventricular wall stress. They develop a larger number of ventricular ectopics and more complex ventricular arrhythmias when compared to normal hearts. This may be of relevance to arrhythmic sudden death in hypertensive patients in whom left ventricular hypertrophy, potassium depletion, and blood pressure lability is common. Excessive fluctuations in systolic pressure and therefore ventricular wall stress could provide a powerful arrhythmic stimulus in hypertensive patients with left ventricular hypertrophy, even before ischaemia, cardiac failure, or extensive extracellular fibrosis have developed.

The enantiomeric separation of metipranolol and desacetylmetipranolol on a cellulose tris-3,5-dimethylphenyl-carbamate chiral stationary phase

A high-performance liquid chromatographic (HPLC) method is described for direct separation of the enantiomers of metipranolol and its principal degradation product and main metabolite, desacetylmetipranolol. Separations are performed on a chiral stationary phase of cellulose tris-3,5-dimethylphenyl carbamate (Chiralcel OD), with hexane-propan-2-ol-diethylamine elution and UV detection at 278 nm. The method affords identification and determination of the optical purity of the bulk drug and its formulated ophthalmic products.

The effects of sodium bicarbonate and a mixture of sodium bicarbonate and carbonate ("Carbicarb") on skeletal muscle pH and hemodynamic status in rats with hypovolemic shock

Rats rendered hypotensive and acidotic by withdrawal of blood were treated by infusion of either an equimolar mixture of sodium bicarbonate and sodium carbonate ("Carbicarb"), sodium bicarbonate alone, or sodium chloride. Skeletal muscle intracellular pH (pHi) was measured using magnetic resonance spectroscopy from the chemical shift of the carbon-2 (C2) proton resonance of the imidazole ring of anserine. In the groups treated with alkali, arterial blood pH (pHa) was restored to normal, but no change was observed in the sodium chloride-treated animals. Despite an elevation of arterial blood partial pressure of CO2 (PaCO2) in the group treated with sodium bicarbonate, no significant change in pHi was observed in any group. Blood lactate levels, initially elevated in all groups, underwent only minor changes. In all three groups a transient and similar elevation of arterial blood pressure was observed after infusion. Differential effects of Carbicarb and sodium bicarbonate in metabolic acidosis may be dependent on the model of metabolic acidosis used, and an alteration in PaCO2 induced by alkali therapy may not be a major determinant of changes in pHi.

Differentiation of beats of ventricular and sinus origin using a self-training neural network

Despite advances in the computerized detection of arrhythmias, arrhythmia recognition by morphological waveform analysis still poses a difficult problem. Artificial neural networks, computer algorithms that are self-trained by an analog of biological synaptic modification to perform pattern recognition, hold great promise for the differentiation of various cardiac rhythms. The goal of this study was to differentiate beats of sinus and ventricular origin on a global basis and on a patient-specific basis by the use of artificial neural network analysis. Neural networks were trained to recognize digitized intracardiac electrograms (9 patients) and surface electrocardiograms (11 patients) obtained during sinus rhythm and ventricular tachycardia. After training, sinus rhythm or ventricular tachycardia beats were input into the neural network, and classified as to their origin. By the use of modified receiver operating characteristic curve plots, it was possible to differentiate with high sensitivity and specificity between beats of sinus origin and ventricular origin in all patients. The addition of high amounts of noise to the beats did not markedly degrade the performance of the surface ECG neural networks, and still allowed high sensitivity in differentiating beats of sinus origin from beats of ventricular origin, especially when noise was added to the training set. Neural networks provided sensitive and specific detection of cardiac electrical activity during sinus rhythm and ventricular tachycardia, and may play an important role in allowing development of improved arrhythmia recognition and management systems.

Echocardiographically guided electrophysiologic testing in pregnancy

Electrophysiologic testing is usually performed with fluoroscopy to guide catheter positioning. This method of visualizing catheter placement may not be ideal for patients who are pregnant. We report four cases of echocardiographically guided placement of catheters for electrophysiologic testing because of the consideration of pregnancy. Adequate visualization of catheters was possible, allowing for proper catheter positioning and complete electrophysiologic testing, including the recording of atrial, His-bundle, and ventricular potentials, as well as cardiac stimulation and induction of tachycardia. This method holds promise for patients in whom fluoroscopy may be relatively contraindicated, such as pregnant patients, as well as patients in whom it is desirable to avoid x-ray exposure such as women of childbearing age and young children.

Growth and body composition in children infected with the human immunodeficiency virus-1

Anthropometric data were collected on 89 children born to human immunodeficiency virus (HIV)-infected women (37 who seroreverted and 52 who were HIV-infected). The main outcomes included birth weight, gestational age, weight, height, arm muscle circumference (AMC), and triceps skinfold thickness (TSF). Gestational age and birth weight were not different between the two groups. The earliest anthropometric evaluation on seroreverted children (age 19 mo) when compared with HIV-infected children (age 21 mo) revealed that weight and weight-for-height percentiles were significantly different (51% vs 33% and 66% vs 48%, respectively). Height and TSF percentiles were not different, although AMC percentiles were lower in infected children (64% vs 43%). In follow-up evaluations, the weight differences between infected and control children did not change. We conclude that HIV does not affect birth weight, but postnatal events result in altered weight gain in HIV-infected children. Lean body mass is lower than in an HIV-negative comparison group at early stages of HIV infection.

The seasonality of canine births and human campylobacteriosis: a hypothesis

The seasonality of canine births was investigated using records from the Kennel Club and the breeding centre for the Guide Dogs for the Blind Association. In these populations a distinct seasonal pattern was found with a greater number of puppies being born in the summer months than the winter. The hypothesis that the greater number of puppies acquired as pets during the summer months may contribute to the seasonal rise in human campylobacter cases, seen at this time, is discussed.

Introduction and spread of thermophilic campylobacters in broiler flocks

Campylobacteriosis is the most commonly reported infectious cause of human gastroenteritis in developed countries and broiler chickens are considered to be the major food-borne source of the infection. The control of the infection in man depends upon its control in broiler flocks but the epidemiology in poultry is poorly understood. Up to 50 per cent of broiler flocks may be infected and most of the birds in an infected flock carry the organisms until slaughter. Vertical transmission through the egg appears unlikely but there are many other potential sources of the infection for the chicks; direct contact with infected animals or birds has been proposed and there is also evidence for indirect transmission through drinking water or insect vectors. It is suggested that the cross-sectional studies discussed in this review should be followed by well designed case-control studies to test the aetiological hypotheses put forward.

Intergenerational studies of human birthweight from the 1958 birth cohort. II. Do parents who were twins have babies as heavy as those born to singletons?

OBJECTIVE

To ascertain whether maternal twinning influences the previously described association between the birthweight of singleton mothers and their infants.

DESIGN AND SUBJECTS

The association between the birthweight of singleton parents and their offspring and that between twin parents and their offspring was compared using data from the 23-year-old sample of the 1958 British national birth cohort. The numbers available for full comparison were 1027 female and 611 male singleton cohort members, and 26 female and 17 male twin cohort members and their first singleton livebirths.

RESULTS

Of the mothers who had been twins, half had been of low birthweight, and overall their mean weight was 700 g less than that of their singleton counterparts. Nevertheless, the mean birthweight of babies of twin mothers was 133 g, and of twin fathers 94 g, greater than of babies of corresponding singletons. For female, but not male, parents this difference persisted after adjustment for confounding variables.

CONCLUSIONS

We suggest two possible reasons for the difference between the weight of babies of twin and singleton mothers. Firstly, the growth of twins becomes retarded late in pregnancy, possibly after a period critical in determining long-term reproductive effects. Secondly, the twin survivors were of higher birthweight than the original twin cohort, whilst the singleton survivors were more representative of all singleton births, thus introducing a possible bias.

The contrasting effects of parental birthweight and gestational age on the birthweight of offspring

Investigations on intergenerational effects on birthweight have been carried out using the data of the 1958 British National Birthday Trust Fund cohort and its follow-up to 23 years, the National Child Development Study (NCDS-4), which included information on all births to cohort members by that age. This report is directed particularly at ascertaining the independent effect of parental gestational age on babies' birthweight. The two main findings are a direct association between parental and offspring birthweight (significant for both mothers and fathers after allowing for confounding factors), but an inverse association with parental gestational age (significant only for the mothers). It is postulated that at least part of this effect is mediated through the association between maternal fetal growth rate and their babies' birthweight; the faster the rate the shorter the gestational age for a given birthweight. It was not possible to ascertain what part genetic factors played in this relationship. Larger and more informative intergenerational studies are needed to further knowledge on this question.

Impaired acquisition of the Morris water maze following global ischemic damage in the gerbil

Five minutes of global ischemia in the Mongolian gerbil impaired acquisition of a Morris water maze task when testing began 72 h after surgery. In spite of extensive damage to CA1 pyramidal cells, ischemic animals eventually learned to locate a submerged platform and performed normally on a subsequent retention test. Animals that were allowed a more protracted recovery period (21 days) acquired the task as readily as control gerbils. These results suggest that undamaged structures within and external to the hippocampal formation allow spatial learning to proceed at a somewhat reduced rate.

Intergenerational studies of human birthweight from the 1958 birth cohort. 1. Evidence for a multigenerational effect

OBJECTIVE

To investigate possible multigenerational influences on birthweight.

DESIGN

Data from the longitudinal study of one week's births in 1958 up to the age of 23 years, the British National Child Development Study, were utilized. These provide socio-biological information on the parents of the cohort, on the cohort members from birth onwards, and on the pregnancies and the birthweight of any babies born to the cohort members.

MAIN OUTCOME MEASURE

The main outcome was the birthweight of babies born to the cohort members, for whom complete intergenerational data were available for 1638 firstborn. Multiple regression modelling was used to investigate any associations between their birthweight and characteristics of their parents and grandparents.

RESULTS

Significant positive associations were found between babies' birthweight and parental birthweight but not gestational age. For the babies born to female cohort members additional findings included associations between their birthweight and the height of the maternal grandmother and the social class of the maternal grandfather, even after adjustment for such strong predictors of birthweight as maternal weight, smoking habit in pregnancy and baby's sex and birth order.

CONCLUSION

These results thus offer support for a multigenerational influence on birthweight passed through the maternal line.

High dose oral amiodarone loading: electrophysiologic effects and clinical tolerance

Although amiodarone is an effective drug for the treatment of life-threatening ventricular arrhythmias, no standard oral loading dose protocol has been defined, and patients often undergo prolonged hospitalization for amiodarone loading. High dose (greater than 1,800 mg/day) oral loading has usually been reserved for unstable patients with incessant ventricular tachyarrhythmias. The current study was designed to 1) examine the clinical and electrophysiologic effects of a high dose oral amiodarone loading regimen in more stable patients; and 2) ascertain its safety and tolerance, possibly allowing shortened amiodarone loading periods and potentially decreased length of hospital stay. The study group included 16 patients with a history of recurrent ventricular arrhythmias and decreased left ventricular function, who were refractory to prior antiarrhythmic drug therapy. The oral loading protocol was 50 mg/kg per day of amiodarone for 3 days, then 30 mg/kg per day for 2 days, followed by maintenance therapy of 300 to 400 mg twice daily. Electrophysiologic testing was performed at baseline, on days 1 and 5 and during week 6. Amiodarone and desethylamiodarone levels were measured and symptoms monitored. Clinically, the high dose loading protocol was well tolerated in 15 of the 16 patients. Arrhythmias were rendered noninducible by day 1 in three patients and remained noninducible throughout the study period in two of the three. The remaining patients continued to have inducible ventricular tachycardia. Ventricular tachycardia cycle length and right ventricular effective refractory period both progressively increased significantly over baseline, starting on day 1. The 15 patients who remained in the study had no significant side effects during the loading period.(ABSTRACT TRUNCATED AT 250 WORDS)

Mercury in flounder (Platichthys flesus L.) from estuaries and coastal waters of the north-east Irish Sea

This paper reports concentrations of mercury in muscle tissue of flounder (Platichthys flesus L.) from various estuaries and coastal waters of north Wales and north-west England that encompass the north-east Irish Sea. Mercury concentrations were highest within and offshore the Ribble Estuary (0.476 +/- 0.037 mg kg(-1)) but were also high within the Mersey (0.389+/-0.042 mg kg(-1)) and Dee Estuaries (0.295+/-0.065) and at coastal sites in the vicinity. Values for all three estuaries and their near coastal sites were significantly higher than for sites in the north and central sectors of the study area. Regressions of mercury concentration against fish length showed significant relationships and age accumulation for the majority of sites, particularly within or in close proximity to the Mersey, Dee and Ribble Estuaries.

Early influences on the secular change in adult height between the parents and children of the 1958 birth cohort

The present account is of data available from the 1958 British national birth cohort and its follow-up to the age of 23 years. It shows an increase in adult height between the cohort members and their parents, amounting to an average 1.2 +/- 0.11 (SEM) cm between the daughters and their mothers and 3.0 +/- 0.12 cm between the sons and their fathers. Factors in early life which contributed jointly to a significant increase in adult height included, as well as sex and parental height, birthweight and maternal pre-pregnant weight, while increasing gestational age had a negative effect. Overall these factors accounted for 71% of the variance of the cohort members' height. Measuring the intergenerational difference between individual pairs of sons and father and daughters and mothers allows to some extent for social and genetic influences. This showed that the size of the difference was increased by increasing intrauterine growth rate, and falling paternal social class. These findings demonstrate again the lifelong influence on offspring of circumstances pertaining at their birth and explain why it may take more than one generation to overcome the effects of childhood disadvantage.