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A Argilés

Publications and source records attributed to A Argilés.

41 records · Page 3Linked to original sources
PubMed1992

Comparison of hemodialysis and hemodiafiltration: a long-term longitudinal study.

Although hemodiafiltration is purported to provide better cardiovascular stability for dialysis patients; other possible benefits of this therapy have not been well defined. We have compared treatment with hemodialysis (HD) and hemodiafiltration (HDF) in 20 stable patients over a period of 18 months. Dialysis parameters (dialysate composition and flow, duration, dialyzer) were the same in the two periods except for the added convection of HDF and a higher tolerated blood flow in HDF. Cardiovascular parameters were remarkably similar in the two treatment periods, indicating that stable patients do not benefit further from this therapy in terms of these factors. The clearance of urea was significantly improved with HDF, which was reflected in a higher Kt/V and lower TACurea. We observed a significant correlation between Kt/V and PRU in both HD and HDF modes. This correlation was linear and the regression line was similar in both modes. The clearance of beta 2-microglobulin was also significantly improved by HDF compared to HD. Thus the benefit of HDF in stable dialysis patients is the improved clearance of small molecules and beta 2-microglobulin without increasing dialysis time. Further clinical benefits due to the improved clearance may only become apparent with longer follow-up.

Adult↗
PubMed1992

Biochemical characterization of serum and urinary beta 2 microglobulin in end-stage renal disease patients.

Since the identification of beta 2 microglobulin (beta 2-M) in haemodialysis-associated amyloidosis, the biochemical characterization of the different forms of beta 2-M has been sought by several groups. New beta 2-M isoforms (pI 5.1 and lower) have been identified in amyloid deposits, and it has been suggested that they are of pathogenetic importance. The finding of N-terminal proteolysed beta 2-M in amyloid deposits prompted the hypothesis that proteolysis would render beta 2-M more amyloidogenic. Finally, a 'novel beta 2-M' (pI 5.2) with a single amino acid replacement (Asn by Asp at position 17) has been reported as possibly specific for patients with dialysis associated amyloidosis, and consequently proposed as 'the amyloidogenic' form. We purified beta 2-M from serum of a newly haemodialysed patient and from urine of a transplanted patient in the early recovery period. Both patients were clinically amyloid free. Three pure isoforms were obtained from serum (pI 5.7, 5.3, and 5.1) and only two from urine (5.7 and 5.3). Further purification of each isoform was obtained by HPLC in a C4 column. Sequence analysis showed that all isoforms had an intact N-terminus. Tryptic digestion of the serum isoforms was performed after alkylation with iodoacetic acid and the peptides were isolated by HPLC in a C18 column. The 5.3 and 5.1 isoforms had identical peptide patterns with the appearance of an early peak missing in the 5.7 form. The sequence of this peptide showed a replacement of the D 42 (Asp 42) by N (Asn) after K41 (Lys 41).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Retinoic acid affects the cell cycle and increases total protein content in epithelial cells.

Retinoids and particularly retinoic acid (RA) have been incriminated in the adaptation to uninephrectomy and compensatory kidney growth in humans. However, there is no data assessing the effects of RA on renal cells. Since the bulk of the compensatory kidney growth is due to tubular cells, we studied the effects of RA, retinol and epidermal growth factor (EGF) on a rabbit kidney epithelial cell line RK13 in culture. RA significantly increased thymidine incorporation by 42 +/- 8% (P less than 0.01). This increase appeared as soon as three hours after adding RA and could still be observed after five days. Total protein content was also increased by RA by 37 +/- 4% (P less than 0.01). Flow cytometer analysis showed a significant decrease in the percentage of resting cells (G0-G1 phases) induced by RA (-9.4 +/- 2%; P less than 0.01). We observed similar results in growth factor free medium, and the RA induced changes were the same in confluent and non-confluent cells. Retinol did not modify thymidine incorporation or total protein content. EGF increased by 75% thymidine incorporation (P less than 0.01). In serum free conditions RA failed to have a synergistic effect with EGF. These data show that RA is able to induce modifications in kidney epithelial cells compatible with those observed in hypertrophy while retinol is not. These modifications are not due to other growth factor potentiation but to RA itself, and are independent of the contact-inhibition phenomenon.

Animals↗