β-Defensin evolution: selection complexity and clues for residues of functional importance

We have examined the evolution of the genes at the major human beta-defensin locus and the orthologous loci in a range of other primates and mammals. For the first time, these data allow us to examine selective episodes in the more recent evolutionary history of this locus as well as in the ancient past. We have used a combination of maximum-likelihood-based tests and a maximum-parsimony-based sliding window approach to give a detailed view of the varying modes of selection operating at this locus. We provide evidence for strong positive selection soon after the duplication of these genes within an ancestral mammalian genome. During the divergence of primates, however, variable selective pressures have acted on beta-defensin genes in different evolutionary lineages, with episodes of both negative and, more rarely, positive selection. Positive selection appears to have been more common in the rodent lineage, accompanying the birth of novel rodent-specific beta-defensin gene clades. Sites in the second exon have been subject to positive selection and, by implication, are important in functional diversity. A small number of sites in the mature human peptides were found to have undergone repeated episodes of selection in different primate lineages. Particular sites were consistently implicated by multiple methods at positions throughout the mature peptides. These sites are clustered at positions that are predicted to be important for the function of beta-defensins.

Single nucleotide polymorphisms in the leptin receptor gene: studies in anorexia nervosa

Anorexia nervosa is an eating disorder of unknown aetiology. There is significant evidence for a genetic component in the pathogenesis of this disorder. A region on chromosome 1 has been identified as a susceptibility locus. The leptin receptor has been mapped to a similar region, further upstream of this susceptibility locus. Leptin and its receptor are known to be important factors in the control and regulation of body weight. Single nucleotide polymorphisms (SNPs) in the leptin receptor are associated with measures of body weight. In the present study, SNPs in the coding region of the leptin receptor were analysed and their possible association with anorexia nervosa was investigated. Two cohorts of young women, 176 Caucasian anorexia nervosa patients and 152 normal Caucasian females, were genotyped for three SNPs in the leptin receptor. There was no significant difference in allele or genotype frequency, for any SNP, between the normal controls and the cohort of anorexia subjects. There were no significant associations with any genotype and body mass index in either the control or anorexic cohorts. When the anorexic cohort was subdivided into restricting and bingeing/purging behaviours, we found no significant association with any genotype. Analysis of haplotypes showed no significant evidence of association with anorexia. In summary, leptin receptor SNPs do not appear to be important factors in the regulation of body weight in young, pre-menopausal women or have any significant association with anorexia nervosa.

A qualitative study of Australian GPs' attitudes and practices in the diagnosis and management of attention-deficit/hyperactivity disorder (ADHD)

BACKGROUND

The importance of general practice involvement in the care of attention-deficit/ hyperactivity disorder (ADHD) is increasing due to the rising numbers of patients who present with the disorder. It has been suggested by consensus bodies that GPs should be identifying and referring patients at the severe end of the ADHD spectrum and managing those with less severe symptoms. However, GPs' views of their role in ADHD care are unknown.

OBJECTIVE

Our aim was to explore the attitudes and practices of Australian GPs towards the diagnosis and management of ADHD.

METHODS

We conducted a series of focus groups to explore GPs' beliefs regarding the causes of ADHD, their perceived role in ADHD diagnosis and management and their views on the role of behaviour therapies and pharmacotherapies in ADHD management. The subjects were 28 GPs in six focus groups.

RESULTS

GPs in this study did not want to be the primary providers of care for patients with ADHD. Participants indicated a preference to refer the patient to medical specialists for diagnosis and treatment of ADHD, and expressed low levels of interest in becoming highly involved in ADHD care. Concerns about overdiagnosis and misdiagnosis of the disorder, diagnostic complexity, time constraints, insufficient education and training about the disorder, and concerns regarding misuse and diversion of stimulant medications were the reasons cited for their lack of willingness.

CONCLUSIONS

The Australian GPs in this study identify a role for themselves in ADHD care which is largely supportive in nature, and involves close liaison with specialist services.

Variation in the ESR1 and ESR2 genes and genetic susceptibility to anorexia nervosa

There is significant evidence for genetic factors in the susceptibility to anorexia nervosa (AN). Previously genetic variation in the estrogen receptor 2 gene (ESR2) has been studied, however no strong evidence of association with AN has been found. In the present study variation in the estrogen receptor 1 (ESR1) and ESR2 genes was examined. Estrogen receptors have been localised to areas of the brain involved in behaviour and regulation of food intake. The anorexic effects of estrogen are accentuated by stress and thus it is postulated that variation in the estrogen receptors may contribute to the genetic susceptibility to AN in females. A cohort of 170 female, Caucasian AN sufferers and 152 female controls were typed for dinucleotide repeat polymorphisms in both ESR1 and ESR2 and two further SNPs at each locus. Variation at ESR1 was not associated with AN. However an association was found at the ESR2 locus with the heterozygous genotype of the G1082A polymorphism and AN but not with any of the other ESR2 polymorphisms analysed. Analysis of haplotypes at ESR1 and ESR2 showed no significant evidence of association with AN suggesting that the variability in ESR2 alone may contribute to the genetic susceptibility to AN.

Re-evaluation of two simple prognostic scores of outcome after proximal femoral fractures

The Belfast and Newcastle simple prognostic scores of outcome after treatment of proximal femoral fractures were recorded shortly after admission on 250 patients. All patients were then followed until discharge, with 87 of those who were the more physically and socially dependent before admission being transferred after surgery for rehabilitation in a geriatric unit. The hospital mortality rate, a hospital stay of over 6 weeks and two measures of rehabilitation outcome, i.e. a delay of over 3 weeks after the operation in regaining independent mobility and any functional decline on discharge compared with the preadmission situation, were recorded for each patient. The prediction of a higher hospital mortality rate and a delay in reaching independent mobility in more dependent patients with both scores reached statistical significance. Longer hospital stays in the more dependent patients did not occur in a situation where care facilities for dependent patients were readily available. The scores, in particular the Belfast score, can be used to compare the casemix of patients with proximal femoral fractures within and between units over time and can predict mortality and delay in achieving independent mobility. They may be helpful in the early selection of patients for transfer to a geriatric unit or orthogeriatric unit for rehabilitation.

A comparison of the psychosocial aspects of AIDS and cancer-related bereavement

OBJECTIVE

This study compares the psychological symptoms and bereavement distress of individuals bereaved by AIDS with a group bereaved by a cancer death, and addresses the question of whether an AIDS death is associated with a higher rate of adverse psychosocial factors that may increase risk of psychological morbidity in the bereaved individuals.

METHOD

AIDS (n = 28) and cancer (n = 30) bereaved individuals (all within 3 months of the bereavement) completed measures of psychological morbidity and measures addressing a range of other adverse factors, e.g., number of losses, levels of social support and stigma.

RESULTS

The cancer and AIDS bereaved were essentially similar on all psychological symptom measures. The AIDS group reported lower levels of social support in response to the bereavement than cancer bereaved individuals; a greater number of bereavements, were more likely to conceal the cause of death from significant others including their own family and perceived, in some instances, a greater level of rejection from others. The AIDS group reported higher levels of social support from friends than from family.

CONCLUSIONS

At three months following bereavement, AIDS and cancer bereaved were similar in levels of distress. While this may change with the progress of grief over time, it suggests essentially similar early bereavement responses. Those bereaved by AIDS reported a range of other adverse factors such as a greater number of losses, lower social support, stigma, and less open disclosure of the cause of death.

Pain and its control in patients with fractures of the femoral neck while awaiting surgery

A survey, by two methods, of the pain felt preoperatively by 100 elderly patients with an acute fracture of the femoral neck showed that most felt a great deal of pain and that a painless fracture was exceptional. No relationship was found between pain appreciation and the patient's fracture type or their age. One of the methods suggested that elderly patients with preserved mental function felt more pain, and the other that less pain was felt by those taking regular prefracture analgesia. The amount of analgesic drugs given to the patients in this survey seemed inadequate for their levels of perceived pain; accordingly regular measurement by nurses of the degree of pain felt preoperatively by patients with this condition is recommended, together with a greater medical review of the medication being prescribed.

Detrusor hyperreflexia--are there two types?

The concept that elderly patients with urinary incontinence due to detrusor hyperreflexia can be divided into two groups with differing natural histories on the basis of the detrusor contractility found on cystometry is reassessed. Thirty patients shown to have hyperreflexia on urodynamic study for persistent urinary incontinence following a recent neurological lesion had their contractility measured by the suggested criteria of the residual urine following a hyperreflexic contraction and the rate of increase of detrusor pressure. The consistency of contractility on cystometry was also measured by repeating this three times on the same occasion. A spectrum of values for the post-contraction volumes and the rate of increase of detrusor pressure was found. On repetitive cystometry 11 out of 30 patients showed a variable post-contraction residual volume. While impaired contractility is common in detrusor hyperreflexia, the concept of two subgroups is not supported by these results. In some patients cystometric measures of contractility vary considerably on repeating the study on the same occasion.

Proximal femoral fractures in the elderly: does operative delay for medical reasons affect short-term outcome?

Forty patients over 65 years of age with fractures of the proximal femur, whose operation was delayed more than 24 hours after admission for medical reasons, were studied. Length of post-operative stay on the orthopaedic wards, mobility after one month and need for continuing supervision by the geriatric services, after discharge from the orthopaedic wards, were compared with a matched group in whom there was no delay. There were no significant differences between the results of the two groups, suggesting that, if medical conditions are adequately treated before operative fixation of fractures of the proximal femur in elderly patients, the short-term outcome is not adversely affected.