Use of combined hemodialysis/hemoperfusion in chronic uremia

The capacity of charcoal to absorb endogenous and exogenous toxins is well established. It removes substances of higher molecular weight than standard dialysis membranes. The regular use of charcoal hemoperfusion as an adjunct to hemodialysis in chronic uremia is a real prospect capable of improving the patient's clinical and laboratory condition and/or reducing the weekly time of treatment. In line with our previous experience, 5 consenting informed patients on regular dialysis treatment from 9 to 35 months (residual creatinine clearance 0-1.8 ml/min, mean diuresis 350 ml) were treated without interruption for 5-8 months according to a schedule including two combined hemodialysis/hemoperfusion procedures instead of the previous three hemodialysis sessions. Patients were on adequate dialysis and their clinical, metabolic and laboratory conditions were stable. In the hemodialysis/hemoperfusion procedure a cartridge containing 150 g of methacrylate-coated activated charcoal with high biocompatibility was inserted in the dialysis circuit in series with a flat plate or hollow fiber dialyzer. Clinical, laboratory and metabolic conditions remained unchanged in all patients despite the one third reduction in dialysis hours per week. The tolerance of treatment was good: platelets, white cells and fibrinogen were unaffected. The marked reduction in weekly time of treatment led to a more satisfactory personal and social rehabilitation, enabling more patients to be treated with the same facilities.

Present status of hemoperfusion/hemodialysis in Italy

The use of charcoal hemoperfusion in the treatment of chronic renal failure has been proposed and applied by several authors. The availability of coating membranes of increased biocompatibility currently allows a safer and wider use of this purifying technique. It has been recently demonstrated that long-term treatment with combined hemodialysis/hemoperfusion yields an improvement of certain dialysis-resistant uremic signs in patients on regular dialysis treatment, while in selected patients it affords a marked reduction (up to one-third) in the overall time of treatment per week. The tolerance of long-term treatment is good. In line with these findings, a multicenter study has been carried out in Italy with two main aims: (1) to see whether long-term treatment with charcoal hemoperfusion is really safe and substantially free from side effects; (2) to verify in a larger and more varied population of patients whether such long-term treatment actually improves certain uremic signs persisting despite adequate dialysis treatment. A third phase of the multicentric study (reducing the weekly time of treatment) is currently being worked on. Five nephrology and dialysis departments took part in the study: in Bologna, Rome, Chieti, Ancona, and Lecce.

Effects of renal substitutive programs on amino acid patterns in chronic uremia

Abnormalities in the amino acid patterns are a constant finding in chronic renal failure and can be regarded as one of the typical biochemical alterations of uremia. This paper evaluates the long-term effects of various artificial substitutive treatments and renal transplantation on plasma and tissue amino acid patterns in chronically uremic patients. Fifty-three patients were included in the study: 35 on artificial treatments (9 on hemodialysis, 9 on hemofiltration, 4 on hemoperfusion, 6 on continuous ambulatory peritoneal dialysis, and 7 on intermittent peritoneal dialysis) and 18 with well-functioning renal transplants. Complete plasma aminograms were performed in all patients before starting the treatment, and repeated every 3 months up to 1 year (artificial therapies) and 3 years (renal transplantation). The amino acid composition of the bone was also determined in 8 dialysis patients and 9 transplant patients. None of the artificial therapies was associated with normal plasma patterns either in the short- or in the long-term, whereas successful renal transplantation led to normalization of the plasma profile within 2 to 4 months in all patients. However, bone amino acid composition remained altered both in artificially treated and in transplanted patients.

Long-term treatment of chronic renal insufficiency with Ibopamine (SB 7505), a new orally active dopamine-related drug

When administered orally Ibopamine, the diisobutyric ester of N-methyldopamine, has pharmacological properties similar to intravenous dopamine: in particular, both renal blood flow and the urinary excretion of sodium and water increase. The drug also enhances creatinine clearance, both in normal subjects and in patients with impaired renal function. Twenty-eight patients affected with chronic renal insufficiency were treated with oral Ibopamine (100 mg/day) for 4-56 weeks. They were divided into 2 groups according to whether the creatinine clearance was more or less than 15 ml/min: Group 1 contained 21 patients (mean clearance 29.09 ml/min) and Group 2 7 patients (mean clearance 8.42 ml/min). Ibopamine treatment was ineffective in Group 2, while in Group 1 patients there was a statistically significant increase in creatinine clearance (+23% after 3 months, +31% after 6 months). Drug tolerance was excellent from both clinical and laboratory points of view.

[The kidney in shock. Changes of some hemodynamic and bio-humoral parameters. II]

In our experiments on 5 pigs of weight between 40-50 kg we've noticed changes of the parameters occurring precociously during the initial stage of the shock. Particularly we observed a sudden reduction of diuresis reaching total anuria in 15 min and persistence of this anuria for the entire time of the shock (120 min). Immediately after introduction of the removed blood the arterial pressure and the diuresis return to normal value. Concerning the blood flow in renal artery it was observed a gradual decreasing to 10-30 ml/min (normal value = 120-180 ml/min). After the restoration of the blood volume we did'nt notice a clean resumption of the flow although arterial pressure reached normal levels (flow value = 70% of the basal value). The hematic level of K+ undergoes a sudden increase that reaches. Maximal level compatible with animal's life. Within 45-60 min from the beginning of the shock and than decrease with restarting of the diuresis. Creatinine reaches 2 mg/ml in 60 min and remain constant during the following 120 min. The value of the plasma renin were precociously raised, reaching values particularly elevated after 90-120 min from the beginning of the shock and decreasing rapidly with the introduction of the removed blood (parallel behaviour of the arterial pressure).

[The kidney in shock. A new experimental method for the induction of controlled shock. I]

In this research we identify a new experimental model to study the shock-kidney, since this complication occurs with discreet frequency during high surgery operation. The model that better reproduce the surgical shock-kidney is the controlled hypovolemic shock. We used for this experiment five pigs of weight between 40 and 50 kg and were studied the following data: Ecg, arterial pressure, central venous pressure, diuresis (by incannulation of both ureters), renal arterial flow, levels of the renin in the renal vein. The measurements were made before, during and after the shock. The hypovolemic shock was induced by removing from carotid artery a sufficient quantity of blood to bring the pressure to 45-50 mmHg. This pressure level was kept constant for 120 min and then was reported to normal level by introducing the blood previously removed. During the experiment no kind of drugs were used.

Ibopamine (SB 7505) in normal subjects and in chronic renal failure: a preliminary report

1 Pharmacological and experimental studies have shown that ibopamine (SB 7505, di-isobutyric ester of N-methyldopamine) is capable of increasing renal blood flow, diuresis, urinary sodium, potassium and creatinine excretion. 2 SB 7505 was given to twelve volunteer patients, six of whom had normal renal function and six with various degrees of chronic renal impairment. 3 In both groups the drug yielded a prompt increase in urinary excretion of water, sodium and potassium, while creatinine clearance was also seen to increase. 4 Heart rate and arterial pressure were unaffected by SB 7505 in all patients. 5 Results seen encouraging and call for further study on the proper use of the drug in clinical nephrology.

Maternal and infant antibody response to meningococcal vaccination in pregnancy

The antigenic capacity of a mixed vaccine prepared with polysaccharides of meningococcus groups A and C, the placental transfer of antibodies, and the persistence of positive titres in the infant were evaluated in 21 pregnant women and their offspring during an epidemic of meningitis in São Paulo, Brazil; and antibody response was assessed in 29 infants vaccinated at less than 6 months of age. Antibodies were detected by passive haemagglutination; the high titres found and the high frequency of positive results are thought to be due to the use of a more sensitive technique. Increased antibody titres were found in most women, and there was evidence for passive transfer to the newborn, especially with regard to antibody type C. However, passive transfer was irregular, and the presence of antibodies in the mother did not guarantee their presence in the child. Passive transfer lasted for only 2-5 months. Vaccination in children under 6 months of age had poor results; only 1 child seroconverted.