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D L Andress

Publications and source records attributed to D L Andress.

52 records · Page 3Linked to original sources
PubMed1987

Osteomalacia and aplastic bone disease in aluminum-related osteodystrophy.

The bone histology in patients with chronic renal failure and aluminum-related bone disease does not always show the excess accumulation of unmineralized osteoid (matrix) characteristic of osteomalacia. Frequently, bone aluminum accumulation is associated with normal or reduced amounts of unmineralized osteoid and low bone formation and is referred to as aplastic bone disease. In this study, we compared static and dynamic bone histomorphometric parameters and plasma PTH and aluminum levels in 12 patients with osteomalacia and 18 patients with aplastic bone disease who had been receiving dialysis for the same duration to determine if the difference in osteoid accumulation in these 2 lesions might be explained by differences in aluminum accumulation or PTH levels. The stainable bone surface aluminum level was significantly higher in the patients with osteomalacia compared to that in the group with aplastic bone [61 +/- 5% (+/- SEM) vs. 43 +/- 4%; P less than 0.02]. The rates of bone apposition and bone formation were lower in the group with osteomalacia (P less than 0.01). Plasma amino-terminal PTH was not significantly different in the 2 groups. The increment in plasma aluminum levels after a single infusion of deferoxamine was higher in the osteomalacic group than in the aplastic group, suggesting that the patients with osteomalacia accumulated more total body chelatable aluminum than did those with aplastic bone disease during a comparable length of time on dialysis. We conclude that the excess unmineralized osteoid in aluminum-related osteomalacia results from the high rate of total body aluminum accumulation, which directly causes uncoupling of matrix mineralization and matrix production, independent of PTH levels. Patients with aplastic bone disease who have accumulated lesser amounts of total body aluminum fail to develop excess unmineralized osteoid because production and mineralization of matrix are more closely coupled than in the osteomalacic lesion, despite a decline in osteoblast numbers.

Adult↗
PubMed1987

Development and reversibility of aluminum-induced bone lesion in the rat.

We studied the effect of aluminum injections on bones of rats after intervals of 3, 6, and 9 weeks. To study reversibility, we allowed one group to recover for 3 weeks. Both weanling and adult rats were examined to determine the influence of age. The calcium, phosphate, creatinine, and parathyroid hormone levels were similar in aluminum-treated rats and controls. Aluminum could be seen by histochemical stain after 6 weeks, but at that time the bone was otherwise normal. By 9 weeks the bone formation (as measured by tetracycline labeling) in aluminum-treated rats was severely decreased on trabecular and endosteal surfaces. The periosteal surfaces showed normal formation. After 3 weeks of recovery, the bone formation rate in the young aluminum-treated rats was similar to that in the controls, although the serum and bone aluminum values had not significantly decreased. A higher percentage of aluminum was seen in the cement lines. In the adult rats, the bones had more stainable aluminum, and increased osteoid was noted along trabecular and periosteal surfaces. The doses of aluminum used in these rats greatly exceeded those that cause toxicity in humans; thus these findings may not directly apply to clinical practice. We conclude that aluminum administration can lead to decreased rates of bone formation in the rat, despite normal calcium level and renal function, and without decreased parathyroid hormone levels. The peritoneal route of administration could also have contributed to bone lesions by causing peritonitis, malabsorption, or both. Adult rats showed signs of early osteomalacia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1986

Aluminum-associated bone disease in chronic renal failure: high prevalence in a long-term dialysis population.

Twenty-seven asymptomatic patients treated with hemodialysis longer than 8 years (mean 12.9 +/- 3.1 years) underwent bone biopsy to determine the prevalence of aluminum-associated bone disease. None had excess aluminum exposure from the dialysate. Ten patients (37%) had aluminum-associated bone disease as defined by a bone formation rate (BFR) below normal in the presence of stainable bone aluminum that covered more than 25% of the trabecular surface. The predominant type of bone histology in this group was the aplastic lesion characterized by low bone turnover, a decreased number of osteoblasts, and lack of excess unmineralized osteoid. Osteoblastic osteoid was highly correlated with stainable surface bone aluminum (r = -.82, p less than .001). Among the dynamic bone parameters, the double-tetracycline labeled surface was a more sensitive indicator of impaired bone function than was the bone apposition rate (BAR), since half of the patients with aluminum-associated bone disease had a normal BAR. In all of the biopsies the extent of double-labeled surfaces was inversely proportional to the amount of stainable aluminum on the bone surface (r = -.71, p less than .001), whereas stainable bone aluminum did not correlate with BAR. In seven of the patients with aluminum-associated bone disease, amino-terminal PTH levels were in the normal range while only one patient had a normal plasma mid-region PTH. PTH correlated directly with osteoblastic osteoid, BFR, and double-labeled surfaces. These results indicate that long-term oral aluminum intake in hemodialysis patients results in a high prevalence of aluminum-associated bone disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Bone oxalate in a long-term hemodialysis patient who ingested high doses of vitamin C.

We performed a bone biopsy on a patient who had been receiving hemodialysis for 23 years. The bone had oxalate deposition. Previous bone biopsies had shown osteitis fibrosis without oxalate deposition. The osteoid area was increased (11% of bone area), as was the fibrosis (6.1% of tissue area) and aluminum deposition (38% of surface). Bone formation rate was normal (259 mu 2/mm2/d). We examined bone biopsies of 22 patients who had been receiving hemodialysis for over 10 years, and none had oxalate deposits. We discovered that our patient had been ingesting 2.6 g/d of vitamin C. The bone oxalate deposition may have been caused by the ingestion of high doses of vitamin C.

Ascorbic Acid↗
PubMed1986

Comparison of parathyroid hormone assays with bone histomorphometry in renal osteodystrophy.

Bone biopsies were studied in 67 dialysis patients to determine if a PTH RIA specific for intact plasma PTH is a better predictor of osteitis fibrosa than a RIA that measures inactive carboxy-terminal/midregion plasma PTH fragments. An amino-terminal-specific antiserum that cross-reacts with intact PTH, but not midregion or carboxy-terminal fragments, and an antiserum that cross-reacts with the 44-68 region of the PTH molecule and measures both intact and midregion/carboxy-terminal PTH fragments were used in the comparisons. Plasma PTH concentrations measured by both assays correlated positively with bone formation rate, bone apposition rate, osteoblastic osteoid, osteoclast number, and marrow fibrosis. The optimum predictive value of the amino-terminal PTH assay for osteitis fibrosa was 88%, compared to 74% for the midregion PTH assay. This difference in predictive value could be attributed to the highly significant correlation of marrow fibrosis with plasma amino-terminal PTH. In conclusion, these data suggest that a PTH RIA that uses an amino-terminal-specific antiserum may be a better predictor of osteitis fibrosa in patients undergoing maintenance hemodialysis.

Bone and Bones↗
PubMed1985

Effect of parathyroidectomy on bone aluminum accumulation in chronic renal failure.

In some patients with chronic renal failure, bone mineralization becomes defective after parathyroidectomy for secondary hyperparathyroidism. Because aluminum deposition in bone is associated with impaired bone formation and osteomalacia, we retrospectively studied bone-biopsy specimens from patients on hemodialysis who were not exposed to dialysate contaminated with aluminum, to determine whether aluminum accumulation on bone surfaces was enhanced by parathyroidectomy. Serial biopsy specimens taken before and after parathyroidectomy revealed an increase in the rate of aluminum deposition on the surface of mineralized bone after parathyroidectomy in each of the six patients studied. The accelerated rate of aluminum accumulation could not be explained by changes in the oral aluminum intake. The mean rate of bone formation (+/- S.E.M.) before parathyroidectomy was higher in the six patients than in six control patients who did not undergo parathyroid surgery (586 +/- 147 vs. 237 +/- 85 micron2 per square millimeter per day; P less than 0.05). After parathyroidectomy, the rate of bone formation fell to levels below normal (148 +/- 32 vs. 311 +/- 29 micron2 per square millimeter per day; P less than 0.05) but was not significantly different from the rate in the control group (319 +/- 126 micron2 per square millimeter per day). We conclude that parathyroidectomy in patients with chronic renal failure is associated with enhanced aluminum deposition on the bone surface, possibly as a result of low bone formation. Patients with secondary hyperparathyroidism who may be candidates for parathyroidectomy should be evaluated for aluminum excess before surgery, so that treatment with aluminum chelation may be considered.

Aluminum↗
PubMed1985

Pseudohyperparathyroidism. Syndrome associated with aluminum intoxication in patients with renal failure.

Aluminum intoxication is an increasingly frequent complication of chronic renal failure. Because hypercalcemia, elevated parathyroid hormone levels, and radiologic changes said to be typical of osteitis fibrosa commonly occur with aluminum intoxication, it is frequently confused with hyperparathyroidism. In this report, examples of this dilemma are described. The pathophysiology leading to the confusing clinical picture is discussed, with a suggested approach to the problem.

Adolescent↗
PubMed1984

Phosphorus administration in patients with profound hypophosphatemia.

The influence of severe hypophosphatemia (less than or equal to 1.0 mg/dl) on vitamin D metabolism was prospectively determined in 11 patients before and after intravenous phosphorus administration. Evidence of liver dysfunction was present in ten patients. The mean (+/- SE) plasma 25 hydroxycholecalciferol [25(OH)D] was significantly decreased before phosphorus therapy when compared to control subjects (9.4 +/- 1.3 vs. 17.8 +/- 1.3 ng/ml, P less than 0.001). With phosphorus administration, serum phosphorus increased from 0.59 +/- 0.07 to 2.58 +/- 0.09 mg/dl while 1,25 dihydroxycholecalciferol [1,25(OH)2D] decreased from 34.6 +/- 4.3 to 14.3 +/- 2.9 pg/ml (P less than 0.001). Plasma 25(OH)D, plasma immunoreactive PTH (both amino and carboxyterminal) and serum calcium did not change after phosphorus administration, suggesting that phosphorus alone was responsible for the change in plasma 1,25(OH)2D concentration. An inverse correlation was found between serum phosphorus and plasma 1,25(OH)2D (r = -0.62, P less than 0.005). In addition, a direct correlation was observed between plasma 25(OH)D and 1,25(OH)2D both before (r = 0.66, P less than 0.005) and after (r = 0.74, P less than 0.005) phosphorus administration. Thus, the decrease in 1,25(OH)2D levels with phosphorus therapy suggests a role of serum phosphate in the regulation of this sterol, and hypophosphatemia or phosphorus depletion may change the relationship of substrate [25(OH)D] to product [1,25(OH)2D].

Adult↗
PubMed1984

Use of the deferoxamine infusion test in the diagnosis of aluminum-related osteodystrophy.

The accumulation of aluminum in bone can cause disabling osteodystrophy in patients with renal failure. Because the chelating agent deferoxamine can mobilize aluminum from tissues, we evaluated the effect of a standard intravenous dose of deferoxamine on plasma aluminum concentrations in 54 patients on hemodialysis. Stainable bone aluminum, bone histologic findings, and bone aluminum content were studied. Baseline plasma aluminum concentrations of greater than 200 micrograms/L were associated with aluminum-related osteodystrophy (specificity, 93%), but concentrations of less than 200 micrograms/L did not exclude the diagnosis (sensitivity, 43%). After administration of deferoxamine, the increase in plasma aluminum concentration was 534 +/- 260 (SD) and 214 +/- 92 micrograms/L in patients with and without aluminum-related bone disease, respectively (p less than 0.001), and correlated with the bone aluminum content (r = 0.64). An increment in plasma aluminum concentration of greater than 200 micrograms/L identified 35 of the 37 patients with aluminum-related osteodystrophy; sensitivity was 94% and specificity, 50%. The deferoxamine infusion test is noninvasive, well tolerated, and of value particularly in excluding the diagnosis of aluminum-related osteodystrophy.

Aluminum↗
PubMed1983

High-dose intravenous phosphorus therapy for severe complicated hypophosphatemia.

To evaluate the efficacy and safety of a simple approach to intravenous phosphorus therapy, we prospectively studied ten adult patients with severe hypophosphatemia (less than or equal to 1 mg/dl), two or more clinical reasons for the hypophosphatemia, and normal renal function. They were treated with a solution containing 0.32 mmol of phosphorus per kilogram of body weight. This amount of phosphorus was infused intravenously over 12 hours and repeated every 12 hours until the serum phosphorus was greater than or equal to 2 mg/dl. The serum phosphorus, potassium, magnesium, and calcium levels were measured at six hours, 12 hours, and every 12 hours thereafter. The serum phosphorus level was greater than or equal to 2 mg/dl in one patient at six hours, three patients at 12 hours, three patients at 24 hours, four patients at 36 hours, and one patient at 48 hours. The serum calcium was measured every 12 hours and at no time was any patient dangerously hypocalcemic. Administration of 0.32 mmol of phosphorus per kilogram of body weight intravenously over a 12-hour period is both efficacious and safe in severely hypophosphatemic patients with multiple causes of hypophosphatemia, normal renal function, and no hypercalcemia.

Adult↗
PubMed1982

Treatment of refractory hypophosphatemia.

Profound hypophosphatemia developed in a patient with chronic alcoholism. Multiple causative factors were identified and were thought to account for the initial failure of phosphorus repletion. High-dose intravenous phosphorus was effective in restoring serum phosphorus to normal with no observable adverse effects. Because of the high degree of correlation between hypophosphatemia and hypomagnesemia, we recommended that serum magnesium be determined in all hypophosphatemic patients.

Alcoholism↗