Hemoperitoneum in a continuous ambulatory peritoneal dialysis patient caused by a hepatocarcinoma treated with percutaneous embolization.

Hemoperitoneum is an infrequent but normally benign complication in continuous ambulatory peritoneal dialysis (CAPD) patients. It can occur at any time during peritoneal dialytic treatment. Hemoperitoneum is not associated with a specific disease and usually disappears spontaneously. In 20% of cases, however, hemoperitoneum is severe and requires specific investigation and emergency therapy. We report a case of hemoperitoneum in a 70-year-old, anti-hepatitic C virus-positive woman. After 48 months of CAPD treatment, a bloody peritoneal effluent developed, with severe anemia (hematocrit decreased from 30% to 20%). An abdominal computed tomography scan showed three hepatic lesions with signs of hepatic neoplasms; selective hepatic arteriography confirmed the diagnosis. Chemoembolization of the three lesions was performed, and hemoperitoneum disappeared within a few hours.

Distal arteriovenous fistulas in elderly hemodialysis patients.

Dialysis access procedures and complications are an important cause of morbidity and hospitalization for chronic hemodialysis patients. Subjects over 65 years old have a higher incidence of co-morbid factors (diabetes mellitus, atheros clerosis, neoplasms, heart failure), therefore the correct choice in terms of timing and type of permanent access is extremely important. As elbow fistulas are often complicated by heart failure and PTFE grafts have a higher risk of thrombosis, we decided to evaluate the success rate of distal fistula as primary dialysis access in elderly patients. We carried out a retrospective study to identify survival predictors and actual vascular network saving. Between January 1991 and September 2000, 277 vascular access procedures were performed on 198 elderly patients (age 65 or older). The first anastomosis was positioned as peripherally as possible. In cases of patients with poor peripheral vasculature or three co-morbid factors, vascular access was first created at the origin of radial artery (Toledo-Pereyra fistula). Survival (Kaplan - Meyer analysis) was significantly higher for Toledo-Pereyra fistulas compared to wrist and snuff-box ones, in spite of the presence of a high incidence of co-morbid factors. We conclude that Toledo-Pereyra fistula is an efficient primary choice in elderly patients.

Trace elements and micropollutant anions in the dialysis and reinfusion fluid prepared on-line for haemodiafiltration.

Exposure to the trace elements and micropollutions of tap water may be very considerable in dialysis patients. As few data on trace elements in reinfusion and dialysis fluid for haemodiafiltration (HDF) have been reported, we studied nine trace elements (microg/l; Al, As, Cd, Cr, Cu, Hg, Pb, Se, Zn) and five anions (mg/l; F-, NO2-, NO3-, PO4(3-), SO4(2-)) in tap water, in water after two passages of reverse osmosis (2RO), in dialysate and in on-line prepared reinfusate. NO3- and SO4(2-) were somewhat elevated in our tap water (22.2+/-7.6 and 21.8+/-11.3 mg/l) but decreased (P<0.001) after 2RO (1.4+/-1.5 and 0.9+/-1.1 mg/l); the other anions, which were at a very low level, remained unchanged. All trace elements decreased, with statistical significance only for Al, Cr and Zn from 14.9+/-19.9, 2.6+/-0.6 and 35.1+/-41.1 microg/ to 3.2+/-2.1, 0.2+/-0.2 and 3.5+/-4.8 microg/l, respectively. Due to impurities in concentrate salts for Al (5.4+/-3.1), Cr (0.5+/-0.4) and SO4(2-) (2.4+/-1.8), greater concentrations were found in dialysate and reinfusate than in tap water after 2RO (P<0.03). For all measurements, trace elements and anions were at acceptable levels according to international standards. Simultaneous determinations of trace elements at inflow (Din) and outflow (Dout) of the dialysate as well as in plasma or in whole blood at the beginning of on-line HDF documented Dout/Din>1 for Al, Cu and Zn and a positive gradient between the concentration in blood and dialysate inlet. In conclusion, our dialysate and reinfusate can be considered safe regarding trace elements and micropollution: two passages through reverse osmosis reduces the concentrations of trace elements and anions. The impurities of concentrates are acceptable. Accumulation or depletion of trace elements should be evaluated after longitudinal studies of plasma concentrations.

Plasma or whole blood concentrations of trace elements in patients treated by haemodiafiltration with on-line prepared substitution fluid.

Large membrane pores and large quantities of reinfusion fluids can influence the dialytic balance of trace elements in haemodiafiltration (HDF). As there are no studies in HDF with on-line produced reinfusate, we studied plasma or whole blood (*) concentrations of trace elements (Al, Cd*, Cr* and Se: microg/l; Cu, Pb* and Zn*: microg/dl) of 24 on-line HDF, 20 haemodialysis (HD) patients and 66 490 normal subjects (N). The concentrations of Al (11.7+/-9.5), Cd (0.73+/-0.59) and Cr (6.5+/-6.9) were significantly greater in on-line HDF patients than in normal subjects (6+/-0.4; 0.6+/-0.2; 0.5+/-0.02), but similar to those of HD patients. In on-line HDF patients, Cu (85.3+/-17.7), Pb (8+/-4.6), Se (68+/-27) and Zn (546+/-103) concentrations were less than in normal subjects (108+/-3.4; 11+/-0.8; 95+/-1.8; 673+/-23), and those of Cu and Zn were also less than in HD patients (99.5+/-16.8; 670+/-65). At the end of an on-line HDF treatment (42-69 studies), there was a significant increase in Al (from 12.8+/-9.1 to 15.4+/-8.3), Cr (from 7.2+/-6.4 to 9.5+/-7), Cu (from 97.3+/-21.5 to 109.4+/-27.2) and Zn (from 577+/-108 to 619+/-117). A longitudinal study (n = 16-18) for 12-30 months documented stable concentrations of Al, Cd, Cr, Se and Zn and a significant increase of Cu and Pb to normal concentrations. In conclusion, our on-line HDF patients have elevated Al, Cd, Cr and decreased Cu, Pb, Se, Zn concentrations in plasma or whole blood determinations. Cu and Pb normalize with time; the other trace elements remain stable as documented by numerous determinations. As the values for on-line HDF patients are similar to those of HD patients, the level of accumulation or depletion of trace elements in on-line HDF can be considered as safe as in HD; the increase in Al, Cd, Cu and Zn at the end of treatment may be an expression of the increase of those trace elements linked to proteins.

Nutritional parameters in diabetic patients on CAPD.

In diabetic patients treated with dialysis, morbidity and mortality are more elevated than in nondiabetic patients. For the high dropout of diabetic patients between the first and the second year of treatment not much data are available on their nutritional parameters. For this reason, after excluding patients who had not had a two-years follow-up, we compared two groups of patients, 8 diabetics and 10 nondiabetics, similar in age (66.0 +/- 8.1 vs 65.0 +/- 8.3 years) and weight (61.8 +/- 11.9 vs 62.1 +/- 5.5 kg), measuring their nutritional parameters [body mass index (BMI), normalized protein catabolic rate (PCRN), albumin, transferrin, cholesterol], dialytic dose (Kt/V), renal residual function (RRF) and peritoneal urea (Kdu) and creatinine clearances (Kdcr) after one and 24 months of continuous ambulatory peritoneal dialysis (CAPD). At the start of CAPD, diabetics had greater weekly Kt/V (2.77 +/- 0.68 vs 2.19 +/- 0.35, p < 0.03) for a better residual renal function (5.0 +/- 2.0 vs 2.6 +/- 1.6 mL/min, p < 0.01) and greater loss of proteins in dialysate (7.8 +/- 2.3 vs 5.2 +/- 2.1 g/day, p < 0.05). After 24 months diabetic patients showed a significant decrease in albumin (3.44 +/- 0.34 vs 2.92 +/- 0.33 g/dL, p > 0.01), PCRN (1.21 +/- 0.20 vs 0.92 +/- 0.10 g/kg/day, p < 0.02), and weekly Kt/V (2.77 +/- 0.68 vs 2.25 +/- 0.38, p < 0.05), and a reduction, even if not as significant as with nondiabetic patients, in residual renal function (5.0 +/- 2.0 vs 3.0 +/- 2.3, p = NS). BMI (p < 0.01) was significantly increased in both groups, and this increase is higher in diabetic patients, while transferrin and cholesterol had no significant variations in both groups of patients. Peritoneal clearances did not change in 24 months, whereas the daily protein loss into dialysate was constantly higher in diabetic patients. In conclusion, diabetic patients have, over time, a decrease of total (renal and peritoneal) clearances of urea and creatinine (primarily because of loss of residual renal function, a reduced protein intake (evaluated as PCRN), and an increased loss of proteins from the peritoneum, which bring about a decrease in albuminemia, a possible concomitant cause of the greater morbidity and mortality in diabetic patients.

Continuous on-line determination of recirculation by thermodilution in hemodialysis patients.

The consistency of the determination of A-V fistula recirculation (R) using the thermodilution method (T) with a new probe (blood temperature monitor, BTM Fresenius A.G.) was studied in 32 patients (AVF: proximal 34%, distal 63%, graft 3%). We compared R calculated by T with both the traditional three-sample method (C) and the low-flow three-sample method (L); both BUN and creatinine (CR) were measured in all samples at the beginning and at the end of the session. T was also determined at the 2nd and 3rd hour. There was a significant correlation between T and either C or L at the start of the session (BUN and CR) as well as at the end (only CR). R was higher (11.9 +/- 10) in proximal AVF than in the distal (5 +/- 3.1%; p0.01) when measured by T at the same blood flow (QB: 313 +/- 45 vs 343 +/- 52 mls/min, p = ns). T increased but not significantly by increasing Qb from 150 to 300 mls/min in ten patients. No correlation was found during the session between blood pressure and T variations. In conclusion, T and L give very similar results while C overestimates recirculation. R is easy to perform repeteadly by T with results available online.

Residual renal function and nutritional parameters in CAPD.

In continuous ambulatory peritoneal dialysis (CAPD) residual renal function (RRF) plays an important role in the total amount of weekly clearances of small molecules. The purpose of this study was to determine if there were any differences in certain nutritional parameters between patients with and without RRF, total weekly clearance (KT/V) being equal. Therefore, we compared two groups of patients with equal weekly KT/V: group A without RRF [n = 7, KT/V 2.07 +/- 0.2) and group B with RRF (n = 7, KT/V 2.11 +/- 0.1, urea clearance 1.13 +/- 0.8, creatinine clearance 2.01 +/- 1.5 mL/min, contributing on the average of 15% (range 5.5%-28%) to the determination of KT/V]. The two groups were selected from 52 patients on CAPD for more than 9 months and they were comparable in age (A = 64.6 +/- 7 years, B = 64.1 +/- 7 years), duration of dialysis (A = 39.8 +/- 25 months, B = 36.3 +/- 31 months), body weight (A = 64 +/- 3.9 kg, B = 64.7 +/- 7.4 kg), and body mass index (A = 26.6 +/- 2.9, B = 25.8 +/- 3.6). The two groups turned out to be different in transferrin (A = 209 +/- 51, B = 278 +/- 24 mg/dL, p < 0.006), normalized protein catabolic rate (PCRN) (A = 0.87 +/- 0.07, B = 1.11 +/- 0.07 g/kg/day, p = 0.00), and albumin (A = 3.31 +/- 0.1, B = 3.55 +/- 0.2, p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

High-dose oral calcitriol and zero calcium peritoneal solutions in CAPD patients with refractory secondary hyperparathyroidism.

We evaluated the effect of pulse oral calcitriol (4 micrograms three times weekly for 6 months) on parathyroid function in nine CAPD patients with hyperparathyroidism refractory to conventional low-dose oral calcitriol. Zero calcium peritoneal solutions were used to prevent the development of hypercalcaemia. The peritoneal loss of calcium increased from 168 +/- 40 to 417 +/- 48 mg/day using zero calcium solutions. Pulse oral calcitriol resulted in a significant decrease in PTH (from 617 +/- 272 to 382 +/- 299 pg/ml) by the 15th day of therapy, while serum iCa did not change from baseline. During the first month of therapy the mean PTH levels remained significantly reduced compared to baseline, thereafter PTH increased in four of nine patients. Hyperphosphataemia was not satisfactorily controlled in four patients, despite large amounts of binders used; seven of nine patients developed hypercalcaemia and required either the substitution of calcium acetate for calcium carbonate or reduction of calcitriol dose. Three patients showed a progressive increase in PTH. In conclusion our data suggest that in most CAPD patients with severe hyperparathyroidism oral calcitriol pulse therapy is not effective in maintaining a permanent suppression in PTH levels.

Effects of calcitriol pulse therapy per os in CAPD patients.

Pulse calcitriol therapy (IV or per os) has been efficacious in hemodialysis (HD) patients to inhibit parathyroid hormone (PTH) levels, but there are very poor data for continuous ambulatory peritoneal dialysis (CAPD) patients. For this reason, we used calcitriol (C) per os (0.75-1.5 micrograms three times weekly) in 19/54 patients who had PTH > 150 pg/mL (on peritoneal dialytic treatment for 6-114 months, weekly KT/V 2.01 +/- 0.43); 16% were in therapy with calcium (Ca) carbonate, 26% with calcium acetate alone, and 58% with calcium acetate associated with magnesium (Mg) carbonate and reduction of dialysate Ca (CaD) and dialysate Mg (MgD), respectively, to 1.25 and 0.25 mmol/L. In 5 patients (26%), a further reduction of CaD to 0 mmol/L has been necessary, and 3 patients must be considered nonresponders after three months of treatment. In conclusion, the use of calcitriol as pulse therapy (three times weekly), and at low doses, allows a good control of secondary hyperparathyroidism in 85% of patients who are using phosphate binders without aluminum, if CaD is reduced in some patients to 1.25 or even to 0 mmol/L.

Improvement of secondary hyperparathyroidism and reduction of the set point of calcium after intravenous calcitriol.

In this study we evaluated the effect of intravenous calcitriol on parathyroid function and ionized calcium/PTH sigmoidal curve obtained during low and high calcium hemodialysis in 10 patients with osteitis fibrosa whose secondary hyperparathyroidism was refractory to conventional therapy. After four months of intravenous calcitriol, serum ionized calcium increased from 1.28 +/- 0.08 to 1.37 +/- 0.11 mmol/liter (P < 0.001), serum phosphate from 1.54 +/- 0.18 to 1.79 +/- 0.4 mmol/liter (P = NS), serum calcitriol from 16.7 +/- 9.9 to 34.3 +/- 6.4 pg/ml (P < 0.001), while alkaline phosphatase decreased from 366 +/- 340 to 226 +/- 180 IU/liter (P < 0.05), osteocalcin from 46.4 +/- 20 to 34.5 +/- 15.3 ng/ml (P < 0.05) and basal intact PTH from 1069 +/- 700 to 305 +/- 270 (P < 0.01). Basal PTH started to decrease after one month of treatment prior to the increase in the ionized calcium. Because of hypercalcemia, the dialysate calcium was decreased from 1.75 to 1.5 mmol/liter in three of five patients on hemodialysis and calcium-containing solutions were substituted by calcium-free replacement fluids in four of five patients on hemodiafiltration. Calcitriol dose at the first month of therapy was 5.6 +/- 0.8 micrograms/week, but successively it was decreased because of hypercalcemia to a final dose of 3.6 +/- 1.3 micrograms/week. After intravenous calcitriol the ionized calcium/PTH sigmoidal curve shifted to the left and downward. Maximally stimulated PTH and maximally inhibited PTH obtained during low and high calcium dialysis significantly decreased as did the ratio of basal PTH/PTHmax and the set point of calcium.(ABSTRACT TRUNCATED AT 250 WORDS)

Peritoneography and peritoneal computerized tomography: a new approach to non-infectious complications of CAPD.

The introduction of the contrastographic medium (PG) eventually combined with CT scan (PCT) has been used in the study of non-infectious abdominal complications of patients on CAPD. In 27 patients on CAPD from 0 to 98 months we infused, through the peritoneal catheter, 100-200 ml of iopamidol and 500-2000 ml of peritoneal dialysis solution, effecting radiograms in different projections (27 cases), with contiguous axial scannings of 10 mm (8 cases). The information obtained was useful with regard to the therapeutic choices; it clarified the extent, the width, and the anatomical relations of hernias (7/7); the leakage site at the introduction point of the catheter (2/5), and site of surgical treatment (2/5); an inguinal hernia (1/4) and the previousness of the peritoneovaginal duct (3/4) in cases of the genital oedema; a displaced non-opaque catheter (1/4); obstruction of the terminal hole (2/4); wrapping of the omentum in a catheter malfunction (1/4); the presence of scar tissue and pathological recesses in the reduction of ultrafiltration (2/3); and the extension of secondary scar tissue after surgery and before CAPD was started. There were no infective complications or allergic reactions during the research. In conclusion, after reparative surgical intervention, PG and PCT are simple, convenient investigations, with significant diagnostic usefulness, before the introduction of the catheter and/or in cases of complications during CAPD.

Effect of chronic intravenous calcitriol on parathyroid function and set point of calcium in dialysis patients with refractory secondary hyperparathyroidism.

This study evaluates the effect of intravenous calcitriol on parathyroid function and ionized calcium-PTH sigmoidal curve obtained during low- and high-calcium haemodialysis in 10 patients with osteitis fibrosa whose secondary hyperparathyroidism was refractory to conventional therapy. After 4 months of intravenous calcitriol, serum ionized calcium increased from 1.28 +/- 0.08 to 1.37 +/- 0.11 mmol/l (P less than 0.001), serum phosphate from 1.54 +/- 0.18 to 1.79 +/- 0.4 mmol/l (P NS), serum calcitriol from 16.7 +/- 9.9 to 34.3 +/- 6.4 pg/ml (P less than 0.001), while alkaline phosphatase decreased from 366 +/- 340 to 226 +/- 180 IU/l (P less than 0.05), osteocalcin from 46.4 +/- 20 to 34.5 +/- 15.3 ng/ml (P less than 0.05), and basal intact PTH from 1069 +/- 700 to 305 +/- 270 (P less than 0.01). Basal PTH started to decrease after 1 month of treatment prior to the increase in the ionized calcium. Because of hypercalcaemia the dialysate calcium was decreased from 1.75 to 1.5 mmol/l in three of five patients on haemodialysis, and calcium-containing solutions were replaced by calcium-free fluids in four of five patients on haemodiafiltration. Calcitriol dose, at the first month of therapy was 5.6 +/- 0.8 micrograms/week, but it was successively decreased because of hypercalcaemia to a final dose of 3.6 +/- 1.3 micrograms/week. After intravenous calcitriol the ionized calcium-PTH sigmoidal curve shifted to the left and downward. Maximally stimulated PTH and maximally inhibited PTH obtained during low- and high-calcium dialysis significantly decreased, as well as the ratio of basal PTH/PTHmax and the set point of calcium.(ABSTRACT TRUNCATED AT 250 WORDS)

Ionised calcium changes and parathyroid hormone secretion in haemodiafiltration in relation to substitution fluid calcium content.

This study was carried out to evaluate the acute effect of either 1.75 mmol/l calcium (A-HDF) or bicarbonate-containing and calcium-free (B-HDF) substitution fluid on calcium balance, serum ionised calcium, and intact parathyroid hormone (PTH) during haemodiafiltration (HDF: 1.3 m2 polysulphone dialyser; blood flow rate, 400 ml/min; treatment time 210 min; substitution fluid volume, 10 litres; dialysate calcium, 1.75 mmol/l). During A-HDF calcium balance was slightly positive (1.47 +/- 2.95 mmol), serum ionised calcium increased from 1.24 +/- 0.08 mmol/l to a final 1.46 +/- 0.05 mmol/l at the end of the treatment (P less than 0.001), and PTH decreased from 227 +/- 231 pg/ml to 150 +/- 123 pg/ml (P less than 0.01), during B-HDF calcium balance was negative (-3.06 +/- 1.3 mmol), ionised calcium decreased from 1.29 +/- 0.05 to 1.24 +/- 0.05 mmol/l (P less than 0.05) without inducing a statistically significant increase in PTH. However, in some patients the increase in PTH after treatment was greater than 50%. When the ultrafiltration rate was increased to 75-100 ml/min and bicarbonate-containing and calcium-free replacement fluid was used (B2-HDF), calcium balance became more negative (-9.75 +/- 4.55 mmol) and the decrease of ionised calcium was greater (from 1.3 +/- 0.06 to 1.14 +/- 0.04 mmol/l, P less than 0.01) inducing a significant increase of PTH (from 297 +/- 366 to 443 +/- 518 pg/ml, P less than 0.01). PTH changes were negatively correlated (r = -0.85) to ionised calcium changes during the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hemodialysis and hemodiafiltration on uremic neuropathy.

This study was undertaken to compare the effect of 1 year hemodialysis (HD) or hemodiafiltration (HDF) treatment on peripheral neuropathy. Thus 21 of 42 patients on chronic HD (1-1.3 m2 cuprophane dialyzer, Qb 300 ml/min) were switched to HDF (1.3 m2 polysulfone dialyzer, Qb 400 ml/min, substitution volume 9-13 liters, ultrafiltration rate 60-70 ml/min), while the remaining patients were considered as a control group. Treatment time was scheduled both in HD and HDF to maintain adequate BUN levels in relation to protein catabolic rate. However, HDF provided a significantly greater weekly inulin (MW 5,000) clearance than HD (5.8 +/- 1.2 vs. 1.6 +/- 0.2 ml/min; p less than 0.001). HD and HDF groups were comparable for age, time on dialysis and starting electroneurographic parameters, which were on average within the normal range. After 1 year follow-up, creatinine, hematocrit, calcium, phosphate, PTH, BUN, protein catabolic rate and residual GFR were comparable in the two groups, whereas beta 2-microglobulin was significantly reduced in HDF patients (29 +/- 6.7 vs. 38.8 +/- 13.9 mg/l in HD patients, p less than 0.01). During the 1-year treatment, electroneurographic parameters did not change in HDF patients, whereas a significant decrease of ulnar motor nerve conduction velocity, ulnar muscle action potential amplitudes, median sensory nerve conduction velocity and peroneal muscle action potential amplitudes was detected in HD patients. We conclude that HDF might prevent the worsening of the electroneurographic indices occurring during chronic HD treatment, as it provides a more effective removal of middle and larger molecules than HD. The use of a more biocompatible membrane in HDF might further contribute to this favorable effect on uremic neuropathy.

Effect of high-dose furosemide in refractory congestive heart failure.

High-dose firosemide is considered effective in primary renal sodium retention but is not generally recommended in congestive heart failure. In order to evaluate efficacy and safety of high-dose furosemide (greater than 500 mg/day), the authors studied 20 patients (pts) resistant to therapy (including furosemide less than 500 mg/day) selected from 161 pts admitted for chronic heart failure. All refractory pts (15 men and 5 women, mean age sixty +/- 12 years) were in NYHA class IV and showed hyponatremia (130 +/- 5 mEq/L) and impaired renal function (BUN 31 +/- 14 mg/dL, serum creatinine 1.3 +/- 0.3 mg/dL and BUN/creatinine ratio 23 +/- 7). In addition to digitalis, dopamine, angiotensin-converting enzyme inhibitors, or vasodilators, IV high-dose furosemide (775 +/- 419 mg/day, 500-2000) was given for ten +/- five days under daily clinical and laboratory monitoring. Three pts died of low-output syndrome while 16 pts were upgraded to NYHA class III and 1 pt to class II; a mean weight reduction of 7.3 +/- 2.9 kg in ten + five days (0.80 +/- 0.4 kg/day) and a mean diuresis increase of 88 +/- 57% occurred. The maximal dose of furosemide did not correlate with serum creatinine but did correlate with BUN/creatinine ratio (r = 0.78, p less than .001). Pts were discharged on with chronic heart failure, and 43% in the subgroup in NYHA class IV with hyponatremia. High dose furosemide was effective for rapid removal of excess water and salt in "furosemide-resistant" congestive heart failure. The relationship between renal impairment and maximal furosemide doses seems to confirm the role of renal pharmacokinetics in the appearance of furosemide resistance.

Fluorine concentrations in bone biopsy samples determined by proton-induced gamma-ray emission and cyclic neutron activation.

Fluorine concentrations in bone biopsy samples taken from the iliac crest of subjects, divided into four groups depending on the length of dialysis treatment, and aluminium levels in blood and bone pathology, in terms of osteoporosis, were determined by two instrumental methods. Proton-induced gamma-ray emission (PIGE), making use of the resonance reaction of 19F(p, alpha gamma)16O at 872 keV, and cyclic neutron activation analysis (CNAA), using the 19F(n, gamma)20F reaction in a reactor irradiation facility, were employed. Rutherford backscattering (RBS) was used to calculate the volume, and, hence, mass of the sample excited in PIGE by determining the major element composition of the samples in order to express results in terms of concentration. From this preliminary investigation, a relationship is suggested between fluorine concentrations in bone and aluminium levels in the system.