Resolution of uremic tumoral calcinosis in a patient on peritoneal dialysis with long-term low-calcium dialysate treatment

Tumoral calcinosis is a rare complication in uremic patients. An in-depth review of published literature suggests that most patients with uremic tumoral calcinosis do not respond to medical treatment. Here, we report the case of a patient on peritoneal dialysis who presented with infected multifocal masses on both hip joints and was successfully treated by medical intervention. The patient was diagnosed with uremic tumoral calcinosis by physical examination and radiologic imaging, and treated with low-calcium dialysis and a non-calcium phosphate binder, sevelamer, without increasing the dose of dialysis. At the 36-month follow-up, the majority of masses had disappeared and the patient was asymptomatic.

The Influence of Low Calcium Concentration Hemodialysis on Cardiovascular Response / 대한신장학회잡지

OBJECTIVE: Arterial compliance (AC) reflects the buffering function of the vessel. Low AC caused by arterial stiffness increases pulse pressure amplitude. Therefore, Low AC must be correlated with high cardiovascular mobidity and mortality in HD patients. Dialysate calcium concentration is potentially a main determinant of serum ionized calcium level and the vasoconstriction is associated with high calcium concentration. Therefore, We conducted a study for evaluation of the interdialytic effects of treatment with a low dialysate calcium (LdCa) concentration and high dialysate calcium (HdCa) concentration on the changes of AC, BP, biochemical parameters. METHODS: Eight HD patient (mean age 45.5, sex ratio 1 : 1) were studied. The mean HD period was 3 years. Arterial Compliance, stroke Volume, SBP, DBP, PP, MAP, Ionized Ca, T-CO2, P and CaxP product were compared after treatment with a LdCa and HdCa concentration for each 10 sessions. RESULTS: AC were 0.143+/-0.076 mm2/kPa in baseline, 0.166+/-0.097 mm2/kPa in LdCa (1.25 mmol/L) dialysate, 0.142+/-0.082 mm2/kPa in HdCa (1.75 mmol/L) dialysate. SBP, DBP, MAP and PP were 157.75+/-15.97, 94.25+/-9.48, 114.12+/-10.56, 63.50+/-10.87 mmHg in baseline and 135.25+/-13.00, 78.75+/-11.24, 98.37+/-15.14, 56.50+/-5.95 mmHg in LdCa dialysate and 160.50+/-15.36, 94.05+/-10.34, 115.75+/-9.64, 62.00+/-15.71 mmHg in HdCa dialysate. Ionized Ca were 4.66+/-0.40 mg/dL in baseline, 4.45+/-0.28 mg/dL in LdCa dialysate and 4.65+/-0.43 mg/dL in HdCa dialysate. However, there were no changes of other biochemical parameters. CONCLUSION: Treatment with LdCa dialysis, by minimizing the risk for LdCa-induced hypocalcemia, may have a beneficial role in the prevention of the ongoing reduction of arterial compliance in HD patients and thus improve cardiovascular prognosis.

Clinical Usefulness of Low Calcium Dialysate in CAPD Patients with High Risk of Low-turnover Bone Disease / 대한신장학회잡지

Hypercalcemia is a common complication in CAPD patients treated with calcium-containing phosphate binders and using the standard dialysate(Ca++ : 3.5 mEq/L). Furthermore, the high calcium concentration in standard dialysate may have a suppressive effect on parathyroid hormone(iPTH) level, contributing to the high prevalence of low-urnover bone disease. We studied the effect of low calcium dialysate(Ca++ : 2.5 mEq/L) for those patients with high risk of low- turnover bone disease. Among 386 patients(1996. 1.- 1999. 12.) who had been stable on CAPD for at least 3 months, 46 patients were included in this study. The patients were divided into 3 groups on the basis of the iPTH levels(10 mg/dL) before the conversion to low calcium dialysate. Group 1(n=29), iPTH 10 mg/dL; Group 2 (n=14), iPTH 150 pg/mL and Ca++ >10 mg/ dL. During a 2-month run-in period, those patients were treated with standard dialysate. After that, a 12-month therapy with low calcium dialysate was followed. Biochemical data including calcium, phosphorus, iPTH and alkaline phosphatase were measured regularly and daily phosphate binder and calcitriol intake(pill counting) were assessed during the run-in and therapy period. We obtained the following result: the prevalence of hypercalcemia(Ca++>10.5 mg/dL) was 5.7%(22/ 386 patients). Serum calcium levels decreased during the therapy period(12 months)(10.5+/-1.4 vs 9.4+/-1.3 mg/dL, p<0.05). Serum phosphorus levels remained unchanged. Mean serum alkaline phosphatase level increased(203.0+/-92.9 vs 257.2+/-103.4 U/L, p<0.05). Serum iPTH levels increased (92.7+/-128.8 vs 225.3+/-237.3 pg/mL,p<0.05). The mean intake of oral phosphate binders was not significantly different between run-in period and therapy period. But calcitriol doses increased 0.038+/-0.087 at run-in period to 0.158+/-0.288 tablets/person/day at therapy period(p<0.05). In the six patients, low calcium dialysate was converted to standard dialysate due to high iPTH level (n=3), symptomatic hypo calcemia(n=2), and uncontrolled edema(n=1). In conclusion, in the study of 46 patients over 12 month period, the usage of 2.5 mEq/L calcium dialysate resulted in a significant decrement in calcium levels and increased iPTH levels. Therefore, we propose that dialysis with a low calcium dialysate is an acceptable form of therapy for the patients with high risk of low-turnover bone disease showing hypercalcemia and low iPTH level. However, further study will be needed for evaluating the effect of low calcium dialysate in low-turnover bone disease.

Osseointegration Of Implants In Rabbit Bone With A Low Calcium Diet And Irradiation / 대한구강악안면방사선학회지

PURPOSE: To investigate osseointergration of titanium implants into the tibia of rabbits, which were fed a low calcium diet and irradiated. MATERIALS AND METHODS: To prepare the experimental model, control group was fed a normal diet and experimental group was fed a low calcium diet for 4 weeks. And then, titanium implants were inserted into the tibia of each rabbit. Experimental group was subdivided into two groups; low calcium diet/non-irradiation group and low calcium diet/irradiation group. The low calcium diet/irradiation group was irradiated with a single absorbed dose of 15 Gy at the 5th postoperative days. On the 12th, 19th, 33rd, 47th, and 61st days after implantation(1, 2, 4, 6, and 8 weeks after irradiation), the bone formation in the bone-implant interface area was examined by light microscopy and fluorescent microscopy. RESULTS AND CONCLUSIONS: 1. In the control group, there began to form woven bone in the bone-implant interface area on the 12th days after implantation. As the experimental time was going on, the amount of bone which was in contact with the implant was increased. 2. In the low calcium diet/non-irradiation group, there began to form woven bone in the bone-implant interface area on the 19th days after implantation. Although the amount of bone which was in contact with the implant was increased as the experimental time was going on, the extent of increased bone was slightly weak as compared with control group. 3. In the low calcium diet/irradiation group, there began to form woven bone incompletely in the bone-implant interface area on the 19th days after implantation, but there were vascular connective tissues in the bone- implant interface area over the entire experimental period. 4. In the control group and low calcium diet/non-irradiation group, bone labeling bands were observed on the 33rd days after implantation, which suggests that the bone formation and remodeling was in process, but interstitial bone remodeling was not observed in the low calcium diet/irradiation group.

Clinical Usefulness of Low Calcium Dialysate in Continuous Ambulatory Peritoneal Dialysis (CAPD) Patients / 대한신장학회잡지

Hypercalcemia is a common complication in CAPD patients treated with calcium-containing phosphate binders and using the standard dialysate (SCD) calcium concentration of 3.5mEq/L. We performed a retrospective study in 25 CAPD patients to determine whether a low calcium dialysate (LCD) containing 2.5mEq/L calcium would reduce the incidence of hypercalemia with adequate control of serum inorganic phosphate levels and diminish the need to use aluminum-containing phosphate binders. All patients had previously used SCD before converting to LCD. The incidence of hypercalcemia (more than 2 episodes of corrected serum calcium > or = 10.5mg/dL) tended to be lower after converting to LCDl 0.27 (0-2.76) vs. 0 (0-1.97) episodes/patient-yearl. Intact PTH level increased from 38.8 (0.1-1599.3)pg/mL to 70.6 (9.5-1540.0)pg/mL after conversion, but there was no statistical sifnificance. Serum calcium, inorganic phosphate, alkaline phosphatase and bicarbonate levels did not change after converting to LCD. We were able to reduce aluminum hydroxide dosagel 1.09 (0-10.88) vs. 0 (0-3.26)g/day/patientl and increase calcium carbonate dosage (1.95 0.92 vs. 2.98 2.14g/day/ patient) after conversion significantly (P<0.05). The frequency of peritonitis was similar in LCD and SCD period. In conclusion, low calcium dialysate is useful in diminishing aluminum-containing phosphate binder dosage and increasing calcium carbonate dosage to maintain a similar phosphate value. Its effects on renal osteodystrophy remain to be assessed.

Ultrastructural Study of Human Epidermal Keratinocytes Cultured in Low Calcium Medium / 第二军医大学学报

A low calcium medium developed for epidermal keratinocytes were prepared according to the MCDB 153 modified formula and used in human epidermal keratinocyte culture compared with DMEM culture system. The observation by contrast microscopy and electron microscopy showed that in the low calcium medium keratinocytes grew as a monolayer of high proliferation and had many characteristics of basal cells, with a more rounded shape and large intercellular spaces. Increasing the calcium ion concentration in the medium or changing the other culture conditions the cells in these cultures could be induced stratification and terminal differentiation. The results suggest that the growth, proliferation and differentiation of cultured human epidermal keratinocytes can be controlled and regulated someway.

EFFECTS OF LOW CALCIUM DIET ON DISTAL AND PROXIMAL TIBIAL METAPHYSIS IN MALE RATS / 营养学报

Objective:To investigate the effect of a low calcium diet on the distal and proximal tibial metaphysis in male rats using bone histomorphometrical techniques. Methods:Forty 3-month-old male Sprague-Dawley(SD) rats, with a mean weight of 280?22g, were randomized into five groups. Group one and group two were fed a normal diet (Ca 1.0%) and a very low calcium diet (VLCD ,Ca 0.1%) respectively for one month,and the rest three groups were fed a normal diet (Ca 1.0%), a very low calcium diet (VLCD, Ca 0.1%) and a low calcium diet (LCD , Ca 0.3%) respectively for three months. All animals received double bone fluorochrome labeling prior to sacrifice. At the end of experiment, the left tibiae were harvested for bone histomorphometrical evaluations. Results:After one month, compared to control group, distal tibial metaphysis(DTM) of VLCD did not change significantly but proximal tibial metaphysis(PTM) was decreased significantly whose percent trabecular area (%Tb.Ar) was decreased to 38% (P