Estimation of statistical moments for desferrioxamine and its iron and aluminum chelates: contribution to optimisation of therapy in uremic patients.

We investigated the best time of administration of desferrioxamine (DFO) with respect to the dialysis session, using the approach of the stochastic dynamic system, integrated with the classical pharmacokinetic models. In the 6 patients studied, the mean arrival times of DFO, aluminoxamine (AlO) and ferrioxamine (FO) were, respectively, 193, 1,350 and 126 min, the mean residence times were 1,048, infinite, 1,190 min, respectively. AlO serum levels reach steady state in a mean time of 7 h and 22 min and remain stable in the interdialytic period. FO achieves a peak at the end of DFO infusion and declines during the interdialytic period. DFO, AlO and FO persist a very long time in the body of the uremic patient, thus the dialysis session should be administered when AlO and FO reach steady state. With a dose of 5-10 mg/kg b.w. of DFO, we propose to start the dialysis 8-12 h after the infusion if the main purpose is to treat Al overload or 2-3 h after the infusion if the main purpose is the treatment of hemosiderosis.

Recombinant tissue plasminogen activator (rt-PA) as first-line therapy for declotting of haemodialysis access.

One of the most common complication in haemodialysis patients is thrombosis of the arteriovenous fistula (AVF). Thirty-five patients with a total of 42 thromboses of the angioaccess were infused via a small needle: (i) into the feeding artery (50% of the cases); (ii) into a AVF venous segment of the arteriovenous fistula (42.8%); (iii) directly into the thrombus (7.1%), by rt-PA. After an initial pulse of 5-10 mg, according to body weight, the drug was continuously infused by a pump with the speed automatically programmed in 30 Brescia-Cimino autologous AV fistulae and 12 polytetrafluoroethylene (PTFE) grafts. A complete thrombolysis with return of bruit and thrill was obtained in 71.4% of the cases using a mean drug dose of 21 mg and an infusion time of 3.8 h. All the successful cases underwent haemodialysis via AVF on the same day. No bleeding occurred at remote sites. Local bleeding occurred in 16% of the cases; in no case was it so severe as to require the suspension of the therapy or blood transfusions. The median cumulative duration of patency after thrombolysis was 32.4 months. Respectively 21, 12 and two patients had a functioning angioaccess after 3.6, 32.4 and 36 months from the lytic approach. Failure of the treatment was not related to the patients' gender or age, AVF age, route of administration of the drug, type of vessel (natural or artificial), or delay between the discovery of the fistula occlusion and the start of the therapy. In unsuccessful cases an organic lesion of the vessels was documented by angiography or echo colour Doppler. In summary, rt-PA local infusion provides a useful means of preservation of AV fistulae and may be used as the therapy of first choice in dialysis patients without active bleeding or high bleeding risk.

Dynamics of bone aluminum over one year of functioning renal graft.

The concentration of aluminum (Al) in serum, urine, and bone, as well as bone histomorphometry parameters were studied before and 1 year after kidney transplantation (Tx) in 20 dialyzed patients. One year after Tx, serum Al fell significantly from 50.3 +/- 8.8 to 23.9 +/- 2.7 micrograms/l, (53% fall). Bone Al content also decreased significantly from 62.9 +/- 9.0 to 36.5 +/- 7.0 micrograms/kg bone weight, but urine Al excretion was still above normal. The repeat bone histomorphometric examination showed a good recovery of bone resorption which correlated well with serum parathyroid hormone levels, but poorer recovery of indices of bone formation and of the extent of Al deposits in the bone as shown by aluminum staining.

[Achalasic megaesophagus with onset in the 1st year of life. A case report]. / Megaesofago acalasico ad insorgenza nel I anno di vita. Descrizione di un caso.

We report a case of esophageal achalasia in a nine months old baby. Recurrent cough and cyanosis were the most important clinical findings. Esophagomyotomy remarkably improved the clinical symptoms. Disorders of esophageal motility may be an important cause of respiratory emergencies in the first year of life.

Serum aluminium level in the veneto chronic haemodialysis population: cross-sectional study on 1,026 patients.

A total of 1,026 patients undergoing haemodialysis as the only chronic treatment were studied in all the dialysis units of the Veneto region, Italy. Aluminium was determined in water, dialysis fluids, and patients' serum. Aluminium mean concentration was 9.1 micrograms/l in tap water and 13.3 and 15.7 micrograms/l in bicarbonate and acetate haemodialysis fluids, respectively. Patients' serum aluminium mean level was 52.0 micrograms/l with the following frequency distribution: 59.2% below 60 micrograms/l, 25.5% between 60 and 100 micrograms, and 15.3% above 100 micrograms/l. The mean serum aluminium level was higher in patients undergoing haemodialysis with aluminium concentration in fluids over 10 micrograms/l. This was true also in patients not receiving aluminium hydroxide. Furthermore, we found higher average serum aluminium in those treated with aluminium hydroxide more than 3 g/day. No relationship was found between serum aluminium and sex, age, dialytic age, parathyroid hormone, and vitamin D treatment. Moreover, the patients with serum aluminium above 100 micrograms/l had higher serum alkaline phosphatase and lower mean cell volume values. Thus, in our haemodialysis population aluminium overloading occurred in spite of low concentration in water and fluid, and it was a result more of fluid pollution (over 10 micrograms/l) than aluminium hydroxide ingestion (over 3 g/day).