Search PubMed⌕ Search

Biomedical subjects

C Y Pak

Publications and source records attributed to C Y Pak.

331 records · Page 19Linked to original sources
PubMedDate not supplied

Bone disease in primary biliary cirrhosis: increased bone resorption and turnover in the absence of osteoporosis or osteomalacia.

The role of vitamin D in hepatic osteodystrophy was examined. Eleven unselected patients with primary biliary cirrhosis (PBC) were assessed for disorders of mineral and vitamin D metabolism. Six were not receiving supplementary vitamin D, and five were being treated with oral vitamin D (50,000 IU daily). Serum levels of 25-hydroxyvitamin D were normal in all patients receiving oral therapy and in 4 of 6 untreated patients. Levels of serum 1,25-dihydroxyvitamin D and 24,25-dihydroxyvitamin D were normal or near normal in all patients. Studies were repeated after 6 months of therapy with parenteral vitamin D2 (100,000 IU i.m. monthly) in 7 patients. Initial bone histomorphometry revealed no evidence of osteomalacia or osteoporosis. However, the bone resorption surface of trabecular bone was increased. This abnormality was no longer present on repeat bone biopsies obtained after parenteral vitamin D therapy, and bone formation had decreased. In addition, trabecular bone volume remained normal in the face of the lower rate of bone formation. Increased bone resorption surface in the absence of osteoporosis or osteomalacia has not been previously described in PBC. Improvement in this bone parameter, associated with the finding of a decrease in the formation of bone and in hydroxyproline excretion in urine after parenteral vitamin D, suggests that increased turnover may be an early feature of the bone disease which complicates PBC and that parenteral vitamin D may retard the rate at which hepatic osteodystrophy develops in chronic cholestatic liver disease.

Adult↗
PubMedDate not supplied

Clinical pharmacology of sodium cellulose phosphate.

The safety and effectiveness of sodium cellulose phosphate (SCP) in the treatment of calcium urolithiasis of absorptive hypercalciuria was explored. Eighteen patients with absorptive hypercalciuria with intestinal hyperabsorption of calcium, normal or suppressed parathyroid function, and active stone disease received 10 to 15 Gm SCP daily (2.5 to 5 Gm with meals) and 2 to 3 Gm magnesium gluconate daily (1 to 1.5 Gm twice daily orally separately from SCP) for eight to 54 months, while maintained on a moderate calcium and oxalate restriction. During treatment, serum calcium, immunoreactive parathyroid hormone, and urinary cyclic AMP remained within the normal range. Serum alkaline phosphatase and bone density (measured by photon absorptiometry) did not change significantly or remained within normal limits. Serum concentrations of magnesium, copper, zinc, and iron and blood hematocrit were not significantly altered by therapy. However, urinary calcium returned toward normal, and incidence of renal stone formation markedly decreased. The results suggest that SCP is a safe and an effective drug for absorptive hypercalciuria.

Adult↗
PubMedDate not supplied

Effect of slow-release sodium fluoride on cancellous bone histology and connectivity in osteoporosis.

We have previously demonstrated that a treatment regimen of slow-release sodium fluoride (SRNaF) and continuous calcium citrate increases lumbar bone mass, improves cancellous bone material quality, and significantly reduces vertebral fracture rate in osteoporotic patients. In order to assess whether such treatment also improves trabecular structure, we quantitated cancellous bone connectivity before and following 2 years of therapy with SRNaF in 23 patients with osteoporosis and vertebral fractures. In addition, we performed bone histomorphometry on the same sections used for connectivity measurements. There was a significant increase in L2-L4 bone mineral density during therapy (0.827 +/- 0.176 g/cm2 SD to 0.872 +/- 0.166, p = 0.0004). Significant histomorphometric changes were represented by increases in mineral apposition rate (0.6 +/- 0.4 microns/d to 1.1 +/- 0.7, p = 0.0078) and adjusted apposition rate (0.4 +/- 0.3 microns/d to 0.6 +/- 0.4, p = 0.016). On the other hand, trabecular spacing significantly declined (from 1375 +/- 878 microns to 1052 +/- 541, p = 0.05). Two-dimensional quantitation of trabecular struts on iliac crest histological sections disclosed significant increases in mean node number per mm2 of cancellous tissue area (0.22 +/- 0.12 vs. 0.39 +/- 0.27, p = 0.0077), the mean node to free-end ratio (0.23 +/- 0.21 vs. 0.41 +/- 0.46, p < 0.05), and in the mean node to node strut length per mm2 of cancellous area (0.098 +/- 0.101 vs. 0.212 +/- 0.183, p < 0.01). There were no significant changes in any of the measurements associated with free-end number or free-end to free-end strut length.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMedDate not supplied

Sequential changes in bone density before and after parathyroidectomy in primary hyperparathyroidism.

Bone density (bone mineral content/bone width) was determined by iodine-125 (125I)-photon absorptiometry in the distal third of the radius before and after successful parathyroidectomy in 37 patients with primary hyperparathyroidism. Bone density progressively declined during the two years immediately preceding surgery. It rose by 6.4% during the first year following surgery but remained stable thereafter. The results suggest that photon absorptiometry analysis of bone density may disclose continuing bone loss before surgery and may show a partial recovery of bone loss that may ensue after successful parathyroidectomy.

Bone and Bones↗