Government advice on peanut avoidance during pregnancy – is it followed correctly and what is the impact on sensitization?

BACKGROUND: In 1998, the UK government issued precautionary advice that pregnant or breast-feeding women with a family history of atopy, may wish to avoid eating peanuts during pregnancy and lactation. This study aimed to assess the compliance with this recommendation and investigate its impact upon peanut sensitization. METHODS: A total of 858 children born immediately after the advice were followed for 2 years and assessed for peanut sensitization. A standardized questionnaire was used to ascertain history of atopy and maternal exposure to peanuts during pregnancy. Following parental consent children were skin prick tested to assess sensitization to peanuts. RESULTS: Sixty-five per cent of mothers had avoided peanuts during pregnancy. Forty-two per cent of the mothers had heard about the government advice, and half modified their diet as a consequence. Neither maternal nor family history of atopy had any significant effect on peanut consumption. Parity did play a role, and mothers having their first child were twice as likely to change their diet (P<0.001). Mothers of 77% of the children sensitized to peanuts had avoided peanuts during pregnancy. In this cohort study maternal consumption of peanut during pregnancy was not associated with peanut sensitization in the infant. CONCLUSIONS: The majority of mothers in this cohort avoided peanut consumption during pregnancy. It is likely that either the government advice is misunderstood by mothers, or that those who communicate the advice have not fully explained who it is targeted at.     

A likelihood approach to HLA serology.

A likelihood approach to HLA serology has been developed in which the aim is not to define a recognition set for a serum but to describe the serum's ability to react with each and every antigen in the test cells, this ability being quantified in terms of the probability of a positive reaction. For a given set of probabilities, one for each antigen, it is possible to derive the probability of the observed set of reactions (the likelihood of the set of probabilities). The maximum possible value of the likelihood for any possible combination of the probability set can then be sought, but this requires a maximization of likelihood with respect to 60-100 independent parameters. Theoretical considerations of the shape of the likelihood surface prove that, in this particular case, this is a feasible proposition. This approach allows the recognition of three groups of antigens: those for which there is considerable evidence of a specificity, those for which there is either no specificity or a very weak specificity, and those for which there is insufficient evidence on which to base a conclusion. The existence of a specificity can be tested using a log likelihood ratio as a statistic, but the usual assumption of a chi 2 distribution of this statistic cannot automatically be made in this situation. Therefore, the distribution is estimated by simulation. A serologist using this approach would receive considerably more information as to the serum's reaction patterns and valid statistics for the existence, or not, of a specificity.     

No linkage or association between multiple sclerosis and the myelin basic protein gene in affected sibling pairs.

Myelin basic protein was examined as a candidate gene for susceptibility to multiple sclerosis using two adjacent amplification fragment length polymorphisms (AmpFLPs), containing seven and six highly informative alleles respectively. No allelic association was found with multiple sclerosis, comparing 77 cases and 88 controls, and there was no evidence for linkage in 73 affected sibling pairs, using the methods of identity by descent and identity by state.     

'Acute on chronic' effect of depot leuprolide in patients with stage D2 cancer of prostate

During a phase III open study of depot leuprolide for stage D2 cancer of the prostate, we studied the effect of depot leuprolide on chronic leuprolide users. To determine whether there was a transient elevation of testosterone or luteinizing hormone (LH) 4-24 h and 3-5 days following the monthly injections, we monitored the changes of testosterone and LH before injection and 24 h post-injection in 10 patients who have been under depot leuprolide Rx for 24-36 weeks, and in 35 patients before injection and 3-5 days post-injection who have received depot leuprolide for 8-24 weeks prior to monitoring. Comparison of the data between pre-injection within 24 h and 3-5 days post-injection showed no significant changes of testosterone and LH values between these levels for either testosterone (P = 0.31) or LH (P = 0.45). We therefore conclude that there was no 'acute on chronic' effect of depot formulation in chronic users of depot leuprolide.     

Frontal lobe activation during object alternation acquisition

Object alternation (OA) tasks are increasingly used as probes of ventral prefrontal functioning in humans. In the most common variant of the OA task, subjects must deduce the task rule through trial-and-error learning. To examine the neural correlates of OA acquisition, the authors measured regional cerebral blood flow with positron emission tomography while subjects acquired an OA task, performed a sensorimotor control condition, or performed already learned and practiced OA. As expected, activations emerged in the ventral prefrontal cortex. However, activation of the presupplemental motor area was more closely associated with successful task performance. The authors suggest that areas beyond the ventral prefrontal cortex are critically involved in OA acquisition.