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V Tessore

Publications and source records attributed to V Tessore.

10 recordsLinked to original sources
PubMed2002

Is steam sterilization really making any difference in dialysis-induced cytokine release?

Ethylene oxide (ETO) is presently the most commonly used sterilization method for medical devices. Although alternative sterilization modes such as steam sterilization have been suggested, the effect of steam on dialysis-induced cytokine release is unknown. We enrolled 9 patients on chronic hemodialysis and evaluated at different intervals IL-1beta production while treated with ETO (NC 1785-Bellco) and steam sterilized NC 1785S-Bellco) Synthetically Modified Cellulose (SMC). A basal test during treatment with NC 1785 was performed (A); the same test was set up 4 weeks after treatment with NC 1785S (B) and, lastly, 4 weeks after returning to NC 1785 (C). Peripheral blood mononuclear cells (PBMC) were purified before and after the dialysis session, were isolated on a Ficoll/Hypaque gradient and incubated for 24 h. Spontaneous IL-1beta release was evaluated in the supernatant and in the lysate. In A, IL-1beta levels were (in pg/ml/10(6) cells, in supematant and lysate, respectively): 5.8 +/- 4.8 and 7.6+/-5.2 in pre-HD and 4.68 +/- 3.6 and 9.7 +/- 6.65 in post-HD. These levels showed a clear reduction in B: 2.5 +/- 2.2 and 4.4 +/- 3.1 in pre-HD, and 4.35+/- 6.6 and 7.52 +/- 7.22 in post-HD. In the C test, 4 weeks after the return to the ETO membrane, IL-1beta levels remained unchanged: 2.9 +/- 1.8 and 4.5 +/- 3.1 in pre-HD; and 2.6 +/- 3 and 5.7 +/- 6.6 in post-HD. Statistical analysis showed significant changes in the pre-HD levels both in supematant (p < 0.04) and in lysate (p < 0.04). Steam sterilization of SMC induced a lower spontaneous IL-1beta release, but this effect was not statistically significant due to the large inter-individual variation. Hence, contrary to claims of better biocompatibility, steam sterilization does not result in a reduced production of pro-inflammatory IL-1beta.

Biocompatible Materials↗
PubMed1998

Cytokine production in haemodiafiltration: a multicentre study.

BACKGROUND: Bacterial contamination of dialysate may enhance cytokine production in haemodialysis. We tested the hypothesis that intracellular cytokines could be enhanced in a large group of patients exposed to backfiltration of dialysate over a long period of observation. METHODS: The intracellular cytokine (interleukin-1 receptor antagonist and interleukin-1beta) concentrations in chronic uraemic patients undergoing haemodiafiltration, which is known to be associated with backfiltration (Group II, 12 patients), were compared to those found in patients treated with a modified haemodiafiltration modality without backfiltration (Group I, 16 patients), in patients shifted from one modality to the other (Group III, 27 patients) and in 10 patients on haemodialysis (Group IV) in a 1-year multicentre study. Group V comprised 10 healthy volunteers. All dialysis monitors were equipped with dialysate ultrafiltration systems. Dialysate contamination was studied by the LAL and the peripheral mononuclear cell/interleukin-1beta assays in the presence or absence of polymyxin B. RESULTS: Intracellular interleukin-1 receptor antagonist and interleukin-1beta both increased significantly (P < 0.002) but slowly (after 8 months) in Groups II vs I, and during the 4-month period in haemodiafiltration with backfiltration in Group III. The incidence of post/predialysis concentration ratio (over 1.5) increased two- to threefold in patients treated with haemodiafiltration with backfiltration with respect to haemodiafiltration without backfiltration. Results on the assays for LAL (< 0.5 E/ml) and interleukin-1beta (range 80.1-90.2 pg/5 x 10(6) cells; 70.2-81.3 pg/5 x 10(6) cells with polymyxin B) showed a moderate-to-low degree of dialysate contamination. CONCLUSIONS: Backfiltration of dialysate with moderate-to-low degree of contamination may enhance cytokine synthesis in the long term. Thus, the relevance for dialytic strategies aiming at improving dialysate quality and/or at reducing backfiltration is highlighted.

Adult↗
PubMed1982

Use of uncoated activated carbon hemoperfusion in acute poisoning: in vitro studies.

In acute poisoning the main purpose of any therapeutic approach is a rapid removal of the drug or poison from body tissues. This approach suggested to undertake a study for the development of an uncoated activated carbon hemoperfusion column suitable for acute poisoning. Th clearances were significantly superior compared with a similar device manufactured using coated carbon. The microparticle generation, utilizing a spherical type of activated carbon, was undetectable with the adopted measuring method, well below the US and British Pharmacopeas limits and practically equal to a coated carbon column with identical geometry.

Acute Disease↗
PubMed1975

Adsorption characteristics of cellulose acetate coated charcoals.

The permeability of cellulose triacetate membrane coated activated charcoal is enhanced by treatment with KOH. The adsorption data for creatinine in aqueous solution before and after deacetylation are given. In order to study the usefulness of hemoperfusion associated with dialysis for removal of uremic toxins, some experiments were performed on the adsorption by coated and deacetylated charcoal of molecules of various molecular weights (from 113 to 40,000). Although the adsorption capacity of uncoated charcoal was better, the coated material still shows good properties in the adsorption of glucagon (mol wt 3485). The results on in vitro experiments of vitamin B12 removal by coated charcoal cartridge and CDAK Model 3 dialyzer confirms the usefulness of adsorption technique toward medium molecular weight compounds.

Adsorption↗
PubMedDate not supplied

Hemodiafiltration without replacement fluid. An experimental study.

Paired filtration dialysis (PFD) is the only hemodiafiltration (HDF) technique in which the ultrafiltrate is continuously available but not mixed with the dialysate. As is the case during all convective or predominantly convective techniques, use of a replacement fluid is necessary in an amount equal to the difference between the ultrafiltrate and the desired patient weight loss. This replacement fluid must have an adequate electrolytic composition (Na+, Ca++, and buffer), and must be sterile and pyrogen free. Using an uncoated adsorbent charcoal cartridge (130 g), the ultrafiltrate obtained in PFD was regenerated, eliminating both the small (except for urea, glucose, and phosphates) and medium-to-large solutes but not the electrolytes and bicarbonate. This verified the ultrafiltrate's possible use as replacement fluid. This technique experimentally studied during 24 standard PFD sessions, with a total mean ultrafiltrate of 9,950 +/- 860 ml, allowed a replacement solution to be obtained with the following mean +/- SD composition: pH 7.467 +/- 0.122, HCO3- 27.0 +/- 2.12 mmol/L, Na+ 137.4 +/- 2.6 mmol/L, K+ 4.1 +/- 0.83 mmol/L, Ca++ 1.12 +/- 0.19 mmol/L, urea 68.3 +/- 16.2 mg/dl, creatinine 0.08 +/- 0.02 mg/dl, uric acid 0.05 mg/dl, phosphates 2.77 +/- 0.71 mg/dl, beta-2 microglobulin 0.5 +/- 0.4 mg/L, and atrial natriuretic peptide 4.41 +/- 5.6 pg/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Charcoal↗
PubMedDate not supplied

Assessment of efficiency using on-line urea kinetic modeling in hemodiafiltration.

Urea kinetics has recently been re-evaluated using an on-line urea monitoring system applied to hemodiafiltration. This system allows evaluation of different components possibly responsible for the gap between prescribed and delivered dose of dialysis, such as access and cardiopulmonary recirculation, and altered dialysis parameters, such as blood flow and dialysate flow rates. Furthermore, the system allows prediction of postdialysis rebound urea concentrations. The aim of the present study was to apply the on-line urea monitoring system to assess the dialytic efficiency of double chamber hemodiafiltration in different conditions of blood-dialysate flow rates, reinfusion volumes, and dialyzer configurations (high + low flux membranes or high + high flux membranes) in 10 patients (age, 60 +/- 9 years; dry weight, 65 +/- 5 kg). There was a significantly lower Kt/V (K, dialyzer clearance; t, dialysis time; V, urea distribution volume) at equilibrium with the high + high vs high + low flux configuration, possibly because of a higher tendency toward urea compartmentalization. This difference was evident when reinfusion was performed post dilution. These studies support the concept that small molecular weight uremic toxins may be more efficiently removed using low flux membranes in a modified form of hemodiafiltration.

Blood Flow Velocity↗
PubMedDate not supplied

Evaluation of novel sorbent systems for joint hemodialysis and hemoperfusion.

Hemodialysis is not very effective at removing middle molecular weight species and certain drugs such as salicylates and barbiturates. Carbon hemoperfusion is ineffective in removing urea and water, even when coated microparticles can be generated. To use the advantages of hemodialysis and carbon hemoperfusion without their disadvantages, cuprophan tubular membranes and fibers containing activated carbon have been manufactured. A device called the Hemocarbodialyser, consisting of a sorbent and dialyzing carbon membrane wound onto a coli dialyzer, has been evaluated by the authors. From preliminary results, the Hemocarbodialyser has been shown to be efficient at removing vitamin B12, has high ultrafiltration, and has high dialysance of creatinine and uric acid. The use of activated carbon and aluminum oxide fibers was also evaluated, indicating that fibers containing sorbents, as well as the Hemocarbodialyser, may have clinical importance in the near future, when joint hemodialysis and hemoperfusion is required in hepatic failure, uremia, and acute poisoning.

Acute Kidney Injury↗