Oestrogen replacement therapy may improve memory functioning in the absence of APOE ε4

There is currently intense controversy regarding the use of hormone replacement therapy (HRT) in postmenopausal women, in relation to its therapeutic efficacy in Alzheimer's disease (AD). It has been suggested that the benefits of HRT may be modified by apolipoprotein E (APOE) genotype (the major genetic risk factor for AD). Here we report the findings of the first study designed to systematically explore the interaction of (a) oestrogen replacement therapy (ERT) and (b) possession of an epsilon4 allele of APOE on specific elements of episodic learning and memory that are commonly used indices of age-related cognitive decline. This data represents a cross-sectional analysis of the interaction of ERT and APOE genotype on learning and memory in a cohort of 181 healthy postmenopausal women [ERT users (n = 101, mean age 65.40 +/- 6.34); ERT non-users (n = 80, mean age 67.03 +/- 6.80)] residing in Perth, Western Australia. The highest level of learning (trials 2-5; P < 0.05) and memory (e.g. total number of items recalled; P < 0.05) performance was observed in women taking ERT who were not carriers of the APOE epsilon4 allele. APOEepsilon4 carriers receiving ERT performed no better on episodic memory testing than APOE epsilon4 carriers who were not receiving ERT. These cognitive differences related to genetic profile, were noted on both recall and recognition (P = 0.005) tests of memory. The findings have significance for evaluating whether and when ERT may be clinically indicated. Specifically, ERT may benefit the cognitive functioning of women not carrying the APOE epsilon4 allele.

Psychological treatment for recurrent symptoms of colds and flu in children

The effect of stress management and relaxation with guided imagery on upper respiratory tract infections (URTIs) was investigated in 45 children with a history of 10 or more infections in the past year. To investigate the influence of psychological treatment on mucosal immunity, secretory immunoglobulin A (sIgA) was measured before and during treatment. The number of symptomatic episodes during 13 weeks of monitoring was similar in treatment and waitlist conditions; however, episodes were shorter in stress management and guided imagery conditions than in the waitlist condition. Levels of sIgA increased toward the end of treatment. These findings were confirmed in a replication study. In addition, symptom reduction and improvements in psychological state persisted at 1-year follow-up. The findings suggest that psychological treatment interrupts a chronic illness cycle in children with symptoms of recurrent URTI.

Increased psychosocial stress and decreased mucosal immunity in children with recurrent upper respiratory tract infections

The association between psychosocial stress and susceptibility to upper respiratory tract infection was investigated in 45 children with a history of recurrent colds and flu, and in 45 healthy children of similar age and distribution. In addition, mucosal immune protection against upper respiratory tract infections was assessed by measuring the concentration of secretory immunoglobulin A (sIgA) and its ratio to albumin in saliva. Several dimensions of psychosocial stress, including exposure to stressful experiences, stress-prone personality traits, and signs of emotional disturbance were elevated in children with a history of recurrent colds and flu. Furthermore, lower sIgA/albumin ratios in these children indicated a deficiency in local mucosal immunity. Thus, the findings are consistent with the view that psychosocial stress depletes local immune protection against viral invasion or bacterial colonization of the upper respiratory tract; this depletion may increase susceptibility to colds and flu. Alternatively, psychological disturbances could develop in response to frequent illness.

Secretory immunoglobulin A increases during relaxation in children with and without recurrent upper respiratory tract infections

A diminished mucosal concentration of secretory immunoglobulin A (sIgA) in the upper respiratory tract may increase susceptibility to colds and flu. The aim of the present study was to determine whether sIgA increases during relaxation in children aged between 8 and 12 years with recurrent upper respiratory tract infections. Forty-five healthy children and 45 children with 10 or more upper respiratory tract infections in the previous year were randomly assigned to one of three experimental conditions: relaxation with suggestions to increase immune system proteins, relaxation alone, or a control condition. Samples of saliva were obtained before and after each condition. The concentration of sIgA in the saliva samples was later determined by measuring the rate of precipitation of antigen-antibody complexes to known concentration of sIgA antigen. The concentration of sIgA increased in the relaxation conditions but not in the control condition. The sIgA/albumin ratio (a more specific measure of local mucosal immunity than concentration) increased during the relaxation-suggestion condition but not during the relaxation or control conditions; however, both the concentration of sIgA and the sIgA/albumin ratio increased in proportion to subjective relaxation ratings. Neither response differed between healthy children and children with recurrent infections. The findings indicate that a disturbance in mucosal immunity in children with recurrent colds and flu does not limit increases in sIgA during relaxation. Higher preinfection levels of sIgA correlate with resistance to upper respiratory tract infection, so enhancing the sIgA concentration with relaxation techniques may help children with recurrent infection problems.