Dynamics of bird—dispersed woody species as they take part in succession were examined in a Pinus banksiana stand at Argonne National Laboratory with a focus on the function of small openings in promoting community change. Mathematical models were developed for the three first phases of woody species involvement in succession: input of seeds, germination and 1st—yr survival, and survival to maturity. All species had a 1st—yr survival rate less than 10% of seed input. Each species demonstrated a different degree of dependence on the various factors determining survival to maturity. For example, Prunus serotina balances a fairly low germination rate and a high rate of seed predation with ability to germinate under a wider range of physical conditions (safe sites) than do other species in the study. Vitis riparia, on the other hand, has a high germination rate. Since most seeds of bird—dispersed species are deposited in shade, each species has adapted ways to survive in shade for a limited number of years which is sometimes sufficient to allow for the occurrence of an opening in the forest or for vegetative growth into an existing opening.

Aluminum frequently accumulates in patients with end-stage renal failure. We investigated the value of long-term, intermittent infusions of deferoxamine for the removal of aluminium from bone in seven patients undergoing long-term maintenance dialysis. Transient rises in serum aluminum levels occurred initially after treatment. Three patients who were studied by bone biopsy had absent or reduced levels of bone aluminum. Histologic studies of bone before and after therapy showed differences similar to those observed between patients with uremia who had an accumulation of aluminum in bone and those who did not. The diagnostic value of rises in the serum aluminum level after a single infusion of deferoxamine was studied in 12 patients with and 10 patients without aluminum accumulation in bone. All patients with bone aluminum had rises in serum aluminum levels, but rises were also observed in some patients without bone aluminum. Thus, the test cannot be used to diagnose aluminum accumulation in bone. Urinary aluminum levels increased significantly after a single infusion of deferoxamine in three patients with kidney transplants and accumulation of aluminum in bone. These findings indicate that deferoxamine is beneficial for the therapy of aluminum accumulation in the bone of patients with renal failure.

To study aluminum-related bone disease, bone biopsies and serum biochemical measurements were done in 97 patients on maintenance dialysis and in 100 patients with mild to moderate renal failure. Bone histology, histochemical staining for aluminum and determination of bone aluminum content were done. Stainable bone aluminum was found in 50% of dialyzed patients and in 5% of nondialyzed patients. The finding of stainable bone aluminum in dialyzed patients was associated with high morbidity and mortality; it was not only seen in most patients with low turnover osteomalacia, but also in 47% of patients with mixed uremic osteodystrophy and in 1 patient with predominant hyperparathyroid bone disease. Patients with stainable aluminum had lower bone mass and decreased activity of bone-forming and -resorbing cells. Cumulative doses of aluminum-containing phosphate binders were a major risk factor. Aluminum in drinking water represents an additional risk factor. Neither serum biochemical tests nor single infusion of deferoxamine could be employed as diagnostic tools. Bone biopsies were the only means for diagnosis.

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