Age, growth and mortality of the Inshore Coarl Trout Plectropomus maculatus (Pisces: Serranidae) from the Central Great Barrier Reef, Australia

Age and growth of the inshore coral trout P. maculatus from the central Great Barrier Reef region was determined by studies of annuli in whole and sectioned sagittae. The periodicity of formation of the annulus was validated through tetracycline labelling of mark-recaptured fishes in the wild and of captive fishes in aquaria. Results obtained from three recaptured and five captive fishes showed that annuli are formed once a year during late winter and spring months. von Bertalanffy growth-curve parameters were L∞ = 60.00 cm SL, K= 0.206 and to = - 0.945 year. The oldest specimen examined was a 12-year-old male of 58 cm SL. The total rate of mortality (Z) was estimated to be 0.569.

Deferoxamine-induced bone changes in haemodialysis patients: A histomorphometric study

1. The histological effects of deferoxamine therapy were assessed on transiliac bone biopsies taken after double tetracycline labelling from 16 uraemic patients undergoing chronic haemodialysis, all having aluminium deposits in bone. Eight patients had osteomalacia, five had an ‘aplastic’ bone lesion and three a high bone turnover with a marked increase in osteoid volume. 2. Deferoxamine was administered intravenously once a week at doses ranging from 1 to 6 g for a mean duration of 7.6 ± 3.3 (sd) months. 3. Deferoxamine therapy was associated with significant reductions in stainable aluminium deposits, osteoid volume, osteoid surfaces and thickness index of osteoid seams. The osteoblastic osteoid surfaces as well as the bone formation rates also increased significantly. 4. A rise in resorption parameters and in serum parathyroid hormone levels was observed in patients with osteomalacia. The percentage reductions in stainable aluminium and in osteoid volume were correlated with the degree of hyperparathyroidism. 5. These data show that deferoxamine therapy reduces stainable bone aluminium and improves bone mineralization in low turnover osteomalacia and that the presence of hyperparathyroidism is associated with an increased response to deferoxamine therapy.