A new experimental model for the investigation of sequential hermaphroditism.

The stunning sexual transformation commonly triggered by age, size or social context in some fishes is one of the best examples of phenotypic plasticity thus far described. To date our understanding of this process is dominated by studies on a handful of subtropical and tropical teleosts, often in wild settings. Here we have established the protogynous New Zealand spotty wrasse, Notolabrus celidotus, as a temperate model for the experimental investigation of sex change. Captive fish were induced to change sex using aromatase inhibition or manipulation of social groups. Complete female-to-male transition occurred over 60 days in both cases and time-series sampling was used to quantify changes in hormone production, gene expression and gonadal cellular anatomy. Early-stage decreases in plasma 17ß-estradiol (E2) concentrations or gonadal aromatase (cyp19a1a) expression were not detected in spotty wrasse, despite these being commonly associated with the onset of sex change in subtropical and tropical protogynous (female-to-male) hermaphrodites. In contrast, expression of the masculinising factor amh (anti-Müllerian hormone) increased during early sex change, implying a potential role as a proximate trigger for masculinisation. Collectively, these data provide a foundation for the spotty wrasse as a temperate teleost model to study sex change and cell fate in vertebrates.

Natural sex change in the temperate protogynous Ballan wrasse Labrus bergylta.

Wild Ballan wrasse Labrus bergylta were sampled monthly over 2 years in western Norway to identify the natural process of sex change in this species. Light microscopy of standard histological-stained and immunohistochemistry-treated gonad tissue showed that spermatogonial germ cells tended to proliferate around the periphery of the lamellae before filling into the slowly receding, apoptotic central areas of the lamellae. Sex change occurred following the breeding season. From July to September, fish were most often in an early state of gonadal transition (ET), characterized by degenerating previtellogenic oocytes and pockets of proliferating spermatogonia in the germinative epithelia. The majority of fish with late transitional gonads, that were typically dominated by spermatogenic cells, developing efferent ducts and the beginning of lobule formation, were found between October and November. Sex steroid profiles of fish representing the different sexual phases showed that breeding females had the highest concentrations of 17ß oestradiol (E2 ) and the lowest concentration of 11 ketotestosterone (11KT). Concentrations of E2 decreased greatly in ET fish at the beginning of sex change and remained low in all subsequent phases. The opposite trend was demonstrated in 11KT profiles. Initial-phase female fish had minimal concentrations of 11KT, but these increased during subsequent transitions. Sex change occurred most often in fish 34-41 cm total length (L(T)) and the median of fish in the size-frequency overlap of female and male fish was 36 cm L(T).

The reproductive cycle of female Ballan wrasse Labrus bergylta in high latitude, temperate waters.

This 2 year study examined the reproductive cycle of wild female Ballan wrasse Labrus bergylta in western Norway as a precursor to captive breeding trials. Light microscopy of ovarian histology was used to stage gonad maturity and enzyme-linked immuno-absorbent assay (ELISA) to measure plasma concentrations of the sex steroids testosterone (T) and 17beta-oestradiol (E(2)). Ovarian recrudescence began in late autumn to early winter with the growth of previtellogenic oocytes and the formation of cortical alveoli. Vitellogenic oocytes developed from January to June and ovaries containing postovulatory follicles (POF) were present between May and June. These POF occurred simultaneously among other late maturity stage oocytes. Plasma steroid concentration and organo-somatic indices increased over winter and spring. Maximal (mean +/-s.e.) values of plasma T (0.95 +/- 0.26 ng ml(-1)), E(2) (1.75 +/- 0.43 ng ml(-1)) and gonado-somatic index (I(G); 10.71 +/- 0.81) occurred in April and May and decreased greatly in July when only postspawned fish with atretic ovaries occurred. Evidence indicates that L. bergylta are group-synchronous multiple spawners with spawning occurring in spring and peaking in May. A short resting period may occur between late summer and autumn when previtellogenic oocytes predominate and steroid levels are minimal.

Uptake of self-management strategies in a heart failure management programme.

BACKGROUND: Multidisciplinary heart failure programs including patient education and self-management strategies such as daily recording of body weight and use of a patient diary decrease hospital readmissions and improve quality of life. However, the degree of uptake of individual components of these programs and their contribution to patient benefit are uncertain. METHODS: Patients with heart failure admitted to Auckland Hospital were randomised into the management or usual care groups of the Auckland heart failure management study (AHFMS). Patients in the management group were given a heart failure diary for the recording of daily weights, attended a heart failure clinic and were encouraged to attend three education sessions. Patients in the usual care group received routine clinical care, mainly from general practitioners. Patients were followed to 12 months. This study investigated the uptake of self-management by assessing diary use and self-weighing behaviour in the group receiving the heart failure intervention, and compared the level of knowledge of heart failure self-management of the management group to the control group after 12 months. RESULTS: Of the 197 patients in the AHFMS, 100 patients were included in the management group and received a diary and education about heart failure self-management including monitoring weight daily. Of these patients, 76 patients used the diary. These patients were on more medication; were more likely to attend the education sessions, heart failure clinic, and primary care, and had a lower mortality rate over the course of the study. Variables independently associated with use of the diary included less severe symptoms (OR 15, 95% confidence intervals 1.7, 144), frequent attendance at the heart failure clinic (OR 15, 95% CI 3, 78) and attendance at an education session (OR 8, 95% CI 1.5, 42). Of the 76 patients who used the diary, 51 weighed themselves regularly. More of these patients owned scales at home; they were also more likely to attend the education sessions, and experienced fewer hospital admissions than those patients who did not weigh themselves regularly. Variables independently associated with regular self-weighing included the presence of scales at home (OR 6.3, 95% CI 1.7, 14.1), left ventricular ejection fraction >30% (OR 4.3, 95% CI 1.1, 17.5), and attendance at the education session(s) (OR 6.3, 95% CI 1.7, 14.1). Patients in the management group exhibited higher levels of knowledge at 12 months of follow-up and were more likely to monitor their condition using daily weighing, compared to the control group. CONCLUSIONS: At 12 months of follow-up, implementation of self-management strategies including daily weight monitoring and level of education on self-management was significantly higher in the management group than the control group. For the patients in the management group, not using the diary or inability to perform daily weighing were associated with less frequent attendance at the heart failure clinic and education sessions and poorer health outcomes. In this study, attendance at the education sessions was associated with the adoption of self-management, underlining the importance of education in multidisciplinary heart failure programmes. Self-weighing could be increased by provision of scales to all patients. The subset of patients who did not adopt self-management strategies in this study were at high risk of death or readmission.

Randomized, controlled trial of integrated heart failure management: The Auckland Heart Failure Management Study.

AIMS: To determine the effect of an integrated heart failure management programme, involving patient and family, primary and secondary care, on quality of life and death or hospital readmissions in patients with chronic heart failure. METHODS AND RESULTS: This trial was a cluster randomized, controlled trial of integrated primary/secondary care compared with usual care for patients with heart failure. The intervention involved clinical review at a hospital-based heart failure clinic early after discharge, individual and group education sessions, a personal diary to record medication and body weight, information booklets and regular clinical follow-up alternating between the general practitioner and heart failure clinic. Follow-up was for 12 months. One hundred and ninety-seven patients admitted to Auckland Hospital with an episode of heart failure were enrolled in the study. There was no significant difference between the intervention and control groups for the combined end-point of death or hospital readmission. The physical dimension of quality of life showed a greater improvement in the intervention group from baseline to 12 months compared with the control group (-11.1 vs -5.8 respectively, 2 P=0.015). The main effect of the intervention was attributable to the prevention of multiple admissions (56 intervention group vs 95 control group, 2 P=0.015) and associated reduction in bed days. CONCLUSIONS: This integrated management programme for patients with chronic heart failure improved quality of life and reduced total hospital admissions and total bed days.