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Biomedical subjects

H Husdan

Publications and source records attributed to H Husdan.

At least 19 recordsLinked to original sources

Calcium oxalate kidney stones in patients on continuous ambulatory peritoneal dialysis.

Kidney stones were passed by ten out of 186 patients with endstage renal disease who were treated with continuous ambulatory peritoneal dialysis (CAPD). Stones from seven patients were examined by x-ray diffraction. In five of them the stones were composed of calcium oxalate monohydrate. The urine calcium oxalate activity product was determined in 44 CAPD patients, eight of whom were stone formers, and compared to that of 120 normal volunteers. In CAPD patients, mean urine ionic-calcium concentration was lower than in normal subjects whereas mean urine ionic-oxalate concentration was significantly higher than in normal subjects. In normal urine samples, the calcium oxalate activity product showed a significant correlation with both the urine ionic-calcium and the ionic-oxalate concentrations. In contrast, in CAPD patients the calcium oxalate activity product correlated with the ionic-calcium concentration but not with ionic-oxalate. Although the urine ionic-calcium concentration is lower in CAPD patients than in normal subjects, it is the relative increase in its concentration which appears to be associated with the increased risk of kidney stone formation in these patients. This relative hypercalciuria seems to follow 1,25(OH)2 vitamin D3 administration.

Calcitriol↗

Experimental model for studies of continuous peritoneal'dialysis in uremic rabbits.

In this paper we describe an experimental model designed for studies of continuous ambulatory peritoneal dialysis (CAPD) in uremic rabbits. We preferred the study of uremic animals because it is not known whether peritoneal membrane differs between normal and uremic animals. Animals made uremic after bilateral nephrectomy could not survive on dialysis. Instead, partial nephrectomy of one kidney and partial (5/6) destruction of the cortex of the remaining kidney by electrocauterization provided a simple and reproducible model. CAPD resulted in adequate control of uremia but the animals showed significant decreases in total plasma proteins and weight. This model is suitable for studies of the metabolic complications of CAPD.

Animals↗

Treatment of renal osteodystrophy with 1,25-dihydroxycholecalciferol.

Nine patients with renal osteodystrophy were tested for 6.5 to 35 months with 1,25-dihydroxycholecalciferol (1,25-DHCC). A close biochemical follow-up was performed during the first 6 months of treatment, including biweekly determinations of serum calcium, phosphorus, magnesium, alkaline phosphatase and creatinine levels. A bone biopsy, radiologic investigations and determinations of plasma levels of immunoreactive parathyroid hormone (IPTH) and intestinal absorption of calcium 47 were performed before and after the 6 months. Although the five patients with osteitis fibrosa showed a significant improvement, the four with predominantly osteomalacic lesions showed no response to treatment. These four had a normal initial plasma iPTH level, higher serum calcium levels than the other five patients, extreme sensitivity to 1,25-DHCC, with frequent episodes of hypercalcemia, and only a slightly increased serum alkaline phosphatase level, which remained unchanged during treatment. All but one of the patients, irrespective of the histologic abnormality, showed a decrease in the uptake of radionuclide by bone after treatment. The renal function of one patient, a man with long-standing stable renal failure who had not undergone dialysis, deteriorated during treatment.

Calcitriol↗

A possible role of vitamin D in the genesis of parenteral-nutrition-induced metabolic bone disease.

Patients receiving long term parenteral nutrition may develop metabolic bone disease. In all 11 patients studied, histologic studies of bone showed excessive unmineralized bone tissue despite normal plasma 25-hydroxyvitamin D levels. Three patients also had bone pain and fractures and severe urinary loss of calcium and phosphate. Withdrawal of vitamin D from parenteral nutrition solutions was associated with improved histologic findings of bone in all patients, shown by a decrease in osteoid tissue and an increase in tetracycline uptake. In the three patients with symptoms, bone pain subsided, fractures healed, and urinary loss of calcium and phosphate decreased. Thus, vitamin D may be a factor in the genesis of parenteral nutrition-induced metabolic bone disease.

25-Hydroxyvitamin D 2↗

Reappraisal of protein losses in patients undergoing continuous ambulatory peritoneal dialysis.

Dialysate effluent protein content was measured in 22 patients undergoing continuous ambulatory peritoneal dialysis (9 with and 13 without previous peritonitis). The average amount of protein in those patients without peritonitis was 1.3 g/2 liters exchanged over a 6-hour period, while that of patients with previous peritonitis was 2.6 g/2 liters exchanged over the same period. 71% of protein found in the dialysate of 2 patients was albumin. Despite the difference in the amount of protein lost between those without and those with peritonitis, there was no significant difference in their mean serum albumin levels (3.2 and 3.4 g%, respectively) which were only slightly below the normal range. The previously reported high protein losses in patients undergoing CAPD are probably the result of frequent episodes of peritonitis and a higher number (five) of daily exchanges.

Adolescent↗

The evolution of renal osteodystrophy in patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

Since the introduction of continuous ambulatory peritoneal dialysis by Popovich et al [1] and the subsequent modification of the technique by Oreopoulos et al [2], an increasing number of patients with end-stage renal disease are maintained on this new treatment modality. To date, there has not been any report of the effect of CAPD on the evolution of renal osteodystrophy which is one of the major complications of chronic renal failure. In this report we will present the results of our radiological and biochemical studies of renal osteodystrophy in 28 patients who have been on CAPD from 6 to 23 months.

Adult↗

Studies in inhibitors of calcification and levels of urine saturation with calcium salts in recurrent stone patients.

Studies have been done on patients with recurrent renal calculous disease, measuring in addition to the usual serum and urine constituents the inhibiting capacity of the urine and the activity products of calcium oxalate, octocalcium phosphate and brushite. Studies on the 24-hour urine calcium, phosphorus and uric acid and serum calcium indicate no essential differences between patients with calcium oxalate, mixed or uric acid stones and normal individuals. We were unable to demonstrate a difference in the inhibiting capacity of the urine between normal individuals and patients with calcium oxalate calculi, and levels of saturation of urine with calcium oxalate were identical in the calcium oxalate stone patients and normal individuals. The degree of saturation of urine with calcium phosphate is significantly greater in stone patients.

Calcification, Physiologic↗

A comparison for extracorporeal and travenol coils for the conduct of short haemodialysis: a consumer report.

A cross-over study carried out over a 24 week period during 1975-76 was designed to test the relative merits of Extracorporeal versus Travenol coils for thrice weekly short periods of haemodialysis for patients with end-stage renal failure. Predictability of and capacity for ultrafiltration were excellent and equally good for both products. Leak rates in Travenol coils were 9.3% as compared to 4.3% for Extracorporeal coils. Dialysances of BUN, creatinine, and phosphate were significantly higher with Travenol coils than with Extracorporeal coils, but this increase was not as great as might be expected from the greater surface area of the Travenol coil. Despite the greater functional efficiency of the Travenol coils we could detect no difference in the degree of biochemical control of the patients as judged by standard pre and post dialysis blood chemistries. Residual blood volumes averaged 9 mls for the Travenol coils as compared to 1.6 mls for Extracorporeal coils.

Humans↗

Measurement of free and free-plus-peptide hydroxyproline fractions in plasma.

Plasma hydroxyproline fractions--free-plus-peptide and free--were determined by a method involving centrifugal ultrafiltration and the procedure of Kivirikko et al. [Anal. Biochem. 19, 249 (1967)]. Within- and between-day precision (CV) for the combined fractions was 4--5% and 2.8--6%, respectively. Mean analytical recoveries of free hydroxyproline were 95.2% (87--109%) in the normal range, and 97% (91--108%) in the above-normal range. Normal ranges for plasma hydroxyproline fractions, based on data for 11 men and 19 women, were free-plus-peptide, 7.5--25.3; free, 4.9--22.7; and peptide (calculated), 0.1--5.1 mumol of hydroxyproline per litre, respectively. These ranges showed no sex-related differences and were gaussian in distribution. A factor was derived to transform data on concentrations in ultrafiltrate into plasma concentrations.

Humans↗

Metabolic balance studies in patients with Paget's disease receiving salmon calcitonin over long periods.

Metabolic balance and calcium kinetic studies were performed in four patients with Paget's disease before treatment with salmon calcitonin and during the early and late stages of the treatment, which lasted 9 to 19 months, A significant decrease in bone turnover and 24-hour urine hydroxyproline and serum alkaline phosphatase values was observed in all patients. In contrast, the calcium, phosphorus and magnesium balances did not change significantly. In agreement with this, the partial body calcium, measured by in vivo neutron activation analysis, did not change. Intestinal calcium absorption increased initially, but returned to baseline levels 9 to 19 months after the study began. During the initial period there was a small, significant, but transient decrease in tubular reabsorption of phosphorus; this was accompanied by a significant decrease in serum phosphorus values--probably a direct effect of calcitonin rather than evidence of secondary hyperparathyroidism. Administration of salmon calcitonin to patients with Paget's disease decreases bone turnover without affecting calcium and phosphorus balances.

Aged↗

Measurement of serum and plasma ionic calcium with the "Space-Stat 20 Ionized Calcium Analyzer".

Ca2+ was measured in sera and plasma from 36 normal subjects (18 men 23-57 years old, and 18 women 20-52 years old) with the Space-Stat 20 Ionized Calcium Analyzer. Within-day and between-day precision (CV) for commercial serum-based specimens varied from 0.64-0.96% and 1.1-3.8%, respectively, depending on their mean concentrations. Plasma and serum showed within-day CV's of 1.05 and 0.79%, respectively. The linear regression of serum Ca2+ (y) on plasma Ca2+ (x) was y = 0.63x + 0.45 mmol/litre with a highly significant (P less than 0.001) coefficient of correlation (r) of 0.69. An approximate 5% increase in the mean Ca2+ concentration in serum over that found in plasma is probably due to heparin complexing. No significant sex-related difference was observed for either serum or plasma. The mean Ca2+ concentration of 29 refrigerated specimens tended to decrease in seven days (by 2.3%, not statistically significant). The normal Ca2+ range in serum and plasma (n = 35) was 1.08-1.18 and 1.02-1.14 mmol/litre, respectively.

Adult↗

Serum ionic fluoride: normal range and relationship to age and sex.

We used the Orion fluoride electrode system to determine the normal range of serum ionic fluoride concentrations and to investigate its relationship to sex and age (A). 87 normal men, aged 18-92 years (mean, 46 years), and 49 normal women, age 19-64 years (mean, 38 years), participated in the study. At the 95% confidence limits, males less than 45 years old had a normal range of 0.29 to 1.52 mumol/litre and males greater than or equal to 45 years old 0.29 + 0.0101 (A-45) to 1.52 + 0.0101 (A-45) mumol/litre. Females, however, had a normal range of 0.022A - 0.32 to 0.022A + 1.07 mumol/litre. A group of 51 men 18-44 years old was compared with a group of 36 men 46-92 years old. The mean serum F- of the older group was shown to be significantly greater (P less than 0.01) than that of the younger group. Factors related to serum ionic fluoride values are (a) tea as an important source of dietary F-, (b) the lack of significant variation during daytime hours, and (c) the lack of significant difference in concentration between serum and plsma F-.

Adolescent↗

Excretion of inhibitors of calcification in urine. Part I. Findings in control subjects and patients with renal stones.

The total excretion of inhibitors of in vitro calcification was measured (in inhibiting units per day) in 24-hour urine samples of 11 control subjects and 20 patients with renal calculi. A semiquantitative method incorporating the rachitic rat cartilage technique was used. In both groups there was a significant positive correlation between the number of inhibiting units per day and the daily urine volume. The mean number of inhibiting units per day was significantly (P smaller than 0.05) higher in the stone patients than in the controls. However, the stone-formers had significantly larger (P smaller than 0.01) 24-hour urine volumes. When corrections were made for urine volume there was no significant difference between the two groups. These data suggest that the underlying abnormality responsible for renal stone formation is not a persistent decrease in the total concentration of urinary inhibitors of calcification.

Adult↗

Excretion of inhibitors of calcification in urine Part II. Findings in patients with chronic renal failure.

By means of a semiquantitative method incorporating the rachitic rat cartilage technique, the total urinary inhibitory activity with respect to calcification was compared in 11 control subjects and 20 patients with renal failure. The patients had significantly lower mean values of inhibiting units per day than did the control subjects. Both groups showed a significant positive correlation between the number of inhibiting units per day and urine volume. When urine volume was taken into account in the comparison, the numbers of inhibiting units for patients continued to be lower than the numbers for controls. These findings are consistent with the hypothesis that the increase of inhibitory activity observed in uremic serum is secondary to a decrease in excretion of the responsible factor (or factors) in the urine, and that the factor (or factors) in serum responsible for the inhibition are identical to those in the urine.

Adult↗