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Notes: Objectives  To investigate cardiovascular risk factors and changes in risk factor levels in relation to menopausal stage, hysterectomy status and hormone replacement therapy use in a cohort of women aged 53 years with prospective data on smoking, lifetime socio-economic circumstances, and blood pressure and obesity at age 43 years.Design  A prospective study.Setting  England, Scotland and Wales.Population  A cohort of women from the Medical Research Council Survey of Health and Development.Methods  A total of 1303 women, aged 53 years, from a UK birth cohort study with measures of cardiovascular risk factors were classified by five menopausal status groups (premenopause, perimenopause, postmenopause, hysterectomy and hormone replacement therapy user). Body mass index, glycosolated haemoglobin, blood pressure, high density lipoprotein, low density lipoprotein and total cholesterol measurements were taken, and analysed within the groups taking confounding variables into account. Changes in body mass index and blood pressure measurement in the same women obtained when 43 years of age were also compared.Main outcome measures  Body mass index, glycosolated haemoglobin, blood pressure, high density lipoprotein, low density lipoprotein and total cholesterol.Results  At 53 years, body mass index, waist circumference, total and low density lipoprotein cholesterol, and glycosolated haemoglobin (HbA1c) varied by menopausal status group, but blood pressure did not. Levels of total cholesterol and HbA1c increased across the natural menopause transition, before and after adjustment for body mass index, smoking and lifetime socio-economic circumstances. After adjustment for confounders, levels of risk factors for hysterectomised women were similar to those of naturally postmenopausal women. Women on hormone replacement therapy had lower levels of total and low density lipoprotein cholesterol, HbA1c, and were less obese than postmenopausal women. The lower obesity levels were partly due to these women already being less obese at age 43 years.Conclusions  This study showed that naturally postmenopausal or hysterectomised women had higher levels of metabolic risk factors compared with premenopausal or perimenopausal women of the same age. The long term stability of these differences and their translation into variations in incidence of cardiovascular disease remain to be seen. The lower levels of metabolic risk factors for women on hormone replacement therapy may protect against future cardiovascular disease or may be overwhelmed by other adverse, and as yet unknown, effects of hormone replacement therapy.

Notes: Two experiments were conducted to evaluate the effects of supplementing methionine hydroxy analogue (MHA) on the performance, body composition, and nutrition retention of rainbow trout. In experiment 1, a 2×4 factorial arrangement with two MHA supplemental levels (with and without) and four fish meal replacement levels (25%, 50%, 75%, and 100%, replaced with soybean meal (SBM) and wheat gluten) was used. A fish meal diet was included as a control. Results showed that fish meal replacement levels had significant effects on fish weight gain (WG), feed conversion ratio (FCR), body moisture, crude protein, crude fat, and ash (P〈0.05). In experiment 2, a fish meal reference diet and seven other diets were made using SBM and distiller's dried grain with solubles supplemented with 0, 0, 0.55, 1.1, 1.65, 2.2, and 2.75 g MHA kg−1 diet to replace 50% of fish meal. WG, FCR, and apparent retention of crude protein and phosphorus were significantly improved in rainbow trout fed the diet containing 1.65 g MHA kg−1 diet compared with fish fed an equivalent diet without MHA.

Notes: Burbot Lota lota movement and river discharge were studied in the Kootenai River, Idaho, U.S.A. and British Columbia, Canada, downstream of Libby Dam, Montana, U.S.A. A total of 24 adult burbot with transmitters were tracked from 1994 to 2000, for analysis of a travel distance of ≥5 km in ≤10 days termed ‘stepwise movement’. Of 44 ‘stepwise movements’, significantly greater movements during pre-spawning and spawning were observed when average daily discharges from Libby Dam were 〈300 m3 s−1, with a mean of 176 m3 s−1, similar to pre-dam conditions. Burbot travelled at a greater rate during all seasons (3·36 km day−1) at discharges 〉300 m3 s−1(mean = 1·84 km day−1) than at discharges 〉300 m3 s−1 but no difference was found for the pre-spawning and spawning period. Burbot that started ‘stepwise movements’ in low discharge conditions frequently stopped during low discharges.

Notes: Injection of somatostatin-14 (SS-14) at 5 ng g−1 body mass (BM) into rainbow trout Oncorhynchus mykiss decreased (P 〈 0·05, cubic, r2 = 0·54) levels of growth hormone (GH) (1·5 ± 0·9 ng ml−1v. 6·6 ± 0·6 ng ml−1) over time when compared to controls. Somatostatin-14 at 50 ng g−1 BM also decreased (P = 0·064, quadratic; r2 = 0·30) levels of GH (3·6 ± 2·1 ng ml−1v. 6·6 ± 0·6 ng ml−1) over time compared to controls. In a second study, passive immunization against SS-14 (1 : 25 dose) increased (P = 0·10, cubic, r2 = 0·12) levels of GH (11·0 ± 4·8 ng ml−1v. 5·2 ± 1·4 ng ml−1) over time. Passively immunizing against SS-14 (1 : 50 dose) increased (P 〈 0·05, cubic, r2 = 0·10) levels of GH (8·2 ± 2·3 ng ml−1v. 5·2 ± 1·4 ng ml−1) over time compared to controls. Overall, in the active immunization study there was no difference (P 〉 0·10) in specific growth rate (G) or feed conversion ratio (FCR) between the three treatment groups during the 9 weeks of the study. Only four of the fish immunized against SS-14, however, developed antibody titres against SS. Compared to controls, these fish exhibited a G of 0·89 ± 0·09 v. 0·56 ± 0·09% per 3 weeks and FCR of 0·80 ± 0·04 v. 1·20 ± 0·05 g g−1. In SS-14 immunized fish, levels of GH decreased (P 〈 0·05) by day 63 while levels of insulin like growth factor-I (IGF-I) increased (P 〈 0·05) by day 42 and 63. These results indicate the hypothalamic hormone SS-14 regulates GH secretion similarly in rainbow trout as it does in mammals. Active immunization against SS-14 could improve growth performance in rainbow trout but enhanced G and FCR is dependent upon generation of antibody titres.