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Biomedical subjects

S Alloatti

Publications and source records attributed to S Alloatti.

At least 37 records · Page 2Linked to original sources
PubMed1982

Clinical significance of the detection of circulating immune complexes in lupus nephritis.

32 patients (22 biopsed) with lupus nephritis (LN) were observed for circulating immune complexes (IC). Solid phase C1q (SPC1q) and polyethylene glycol (PEG) precipitation tests were used. The patients were studied during the clinical follow-up in different phases of disease activity. Comparative studies between each histological class of LN and corresponding forms of idiopathic glomerulonephritis (IGN) were made: no significant differences were found between either mesangial LN and stalk mesangial IGN, or between focal proliferative LN an focal proliferative IGN. However, a significant difference was found for SPC1q data between diffuse proliferative LN and mesangiocapillary IGN, and between membranous LN and membranous IGN. LN, with an acute nephritic syndrome and hypocomplementemia, displayed SPC1q data significantly above the levels of IC found in IGN with similar clinical features. IC serum data would seem an important element for the diagnosis and the clinical management of patients affected by LN.

Adolescent↗
PubMed1982

The immunological state in chronic renal insufficiency.

To evaluate the immunological state in chronic renal insufficiency, the Authors studied cellular and humoral immunity in 292 patients with chronic renal failure. They were divided into 3 groups: 1) 37 with creatinine clearance between 50 and 20 ml/min; 2) 57 with creatinine clearance between 20 and 8 ml/min; 3) 178 treated by hemodialysis. In vivo and in vitro tests, that is DNCB, PPD skin tests, spontaneous, active and EAC rosettes, surface membrane immunoglobulin test, complement (C3, C4) and serum immunoglobulins were taken as markers of the immune response. Cell-mediated immunity was found to be significantly impaired in patients with terminal renal insufficiency or on hemodialysis and also markedly reduced in patients with non-terminal renal insufficiency. Humoral immunity produced less significant results: the B lymphocyte count and serum immunoglobulins were normal; only C3 levels were found below normal range. Thus it would seem that cell-mediated immunodeficiency appears in an early stage of chronic renal failure and that hemodialysis does not improve this deficiency.

Adult↗
PubMed1981

Effects of blood transfusion on cellular immunity.

To evaluate the effect of transfusion on immunity, 14 uraemic patients treated with 3 blood transfusions from a single donor, at weekly intervals, were studied: in 5 cases HLA-A,B were compatible, in 9 cases they were not. As markers of cellular and humoral immunity DNCB, PPD skin tests, spontaneous and active E-rosettes, EAC-rosettes, surface membrane immunoglobulins, C3, C4, C3d, serum immunoglobulins, circulating immune complexes and C-reactive protein were investigated. This protocol was applied before transfusions, 1 week after each transfusion (day +7, +14, +21) and 20 weeks later (day +80). Before transfusions 8/14 patients were DNCB negative; both spontaneous and active E-rosettes were below normal range. The other parameters were normal. On day +7 T and B lymphocytes were increased, while the other parameters were unmodified. On day +21 there was a significant reduction (p less than 0.5) in T lymphocytes in patients treated with compatible transfusions. On day +80 3/3 DNCB positive patients, treated with compatible transfusions, became negative and 1/3 DNCB positive patients, treated with random transfusions, also became negative. Three/fourteen patients showed a decrease in B lymphocytes. The other results were unchanged. Our preliminary results suggest that transfusions, either from an HLA compatible donor or not, can impair lymphocyte function.

Adult↗
PubMed1975

[Use of coil negative pressure in the kidney].

A sealed compartment recycling system has been created for use with Extracorporeal commercial filters in order to exploit the negative pressure of the dialysate for purposes of ultrafiltration. The results of in vivo and in vitro tests regarding ultrafiltration and dialysates of urea, creatinine, Hipaque I125 and vit. B12 Co57 are reported. The tests highlighted improved dehydration characteristics in the system compared with the traditional coil technique, while the dialysates of small and medium molecules showed no decrease. The system can profitably be used as an alternative to the open compartment coil system and is particularly interesting because it can be combined with monitors which provide exclusively for the use of closed circuit dialysate instruments.

Creatinine↗
PubMedDate not supplied

Transcellular disequilibrium and intradialytic catabolism reduce the reliability of urea kinetic formulas.

To elucidate the limits of single-pool models as regard aberrations induced by urea transcompartmental disequilibrium during urea kinetics, mass balances and fractional clearances were studied, and original formulas developed to calculate urea clearance and distribution volume. In the early dialytic phases, aberrations were more evident, with low kinetic volume (VK) values and kinetic clearance (KK) values double those obtained by dialysate collection (KDC). Over the whole session, both VDC and VK were underestimated (9.9 and 8.2%), compared with anthropometric data (VA). In 3 patients, the comparison of VA and VDC, and the behavior of effective body water clearance (KE), agreed with the hypothesis of dialysis-induced catabolism. Both disequilibrium and hypercatabolism can affect the reliability of the single-pool urea kinetic model; because of overlap, their effects are difficult to separate, and became particularly important in high-efficiency dialysis. A modified model, using V and CtET as input is suggested in order to establish the most appropriate dialysis prescription for uremia therapy.

Anthropometry↗
PubMedDate not supplied

Accuracy of an on-line urea monitor compared with urea kinetic model and direct dialysis quantification.

To verify the accuracy of a urea monitor (UM) to assess dialysis adequacy, it was compared with a modified direct dialysis quantification method (mDDQ) and with a Casino modified urea kinetic model (mUKM) algorithm. Simplified Jindal and Daugirdas formulas, an anthropometric body water Watson formula, bioelectric impedance analysis, and the Garred model have also been considered. Concerning urea removal, UM results are close to mDDQ, as are the predialytic blood urea nitrogen values obtained by UM in the initial equilibration test. Urea distribution volume results for UM, mDDQ, and bioelectric impedance analysis are similar, whereas it appears clearly overestimated by the Watson formula. Urea monitor clearances are not significantly different from mDDQ, unlike UM Kt/V, which is slightly higher than mDDQ reference value, although with a satisfactory degree of concordance. Rebound effect must be considered by sampling after the equilibration time (et) when mUKM or simplified Kt/V formulas are used: mUKMet Kt/V results are quite similar to mDDQ, as is the Daugirdas value. Regarding NPCR, UM results are neither significantly different from mDDQ nor from the Garred model, whereas mUKM results are significantly overestimated. When rebound is considered, NPCR by mUKMet and NCPR by mDDQ are identical. The UM approach is simple and practical, with a satisfactory degree of reliability for clinical practice.

Adult↗
PubMedDate not supplied

Comparison of a modified urea kinetic model direct dialysis quantification and classic urea kinetic modeling.

In the classic urea kinetic model (UkM), the measurement of clearance (K) as a model input is onerous, and its result is higher than actual body clearance because of urea disequilibrium. Urea kinetics performed by direct dialysis quantification (DDQ), with an equilibrated post rebound sample, gives reliable results but is routinely impractical. The modified UKM (mUKM) method is based on the input of urea distribution volume (V), easily obtainable by several methods and more stable than clearance, and uses simple formulae derived from urea mass balance, avoiding iterative computation. Compared with DDQ, mUKM results are identical, provided that the V value obtained by DDQ is used as input. Compared with UKM, mUKM urea clearances are significantly lower (158.1 +/- 20.5 versus 180.7 +/- 26.8 ml/min), as are urea nitrogen generation rates (5.85 +/- 2.0 versus 6.41 +/- 2.14 mg/min), whereas V results are close (32,444 +/- 6301 versus 32,141 +/- 5293 ml): consequently, mUKM Kt/V is significantly lower than UKM Kt/V (1.07 +/- 0.17 versus 1.22 +/- 0.18). This is because both mUKM and DDQ take account of post dialysis urea rebound. Therefore, if UKM formulae are used with the DDQ body clearance and the equilibrated post rebound blood urea nitrogen value as input data, their results strictly approximate the reference DDQ (V = 32,457 +/- 6274; Kt/V = 1.07 +/- 0.17; G = 5.85 +/- 2.0), demonstrating the common mathematical basis of DDQ and UKM. Therefore, reliable results may be obtained by DDQ, by mUKM, and by "equilibrated" UKM; we suggest that the mUKM model, less cumbersome than DDQ, and more reliable than UKM because it avoids the clearance measurement and the need for iterative computation, could be useful for routine kinetics.

Blood Urea Nitrogen↗
PubMedDate not supplied

Peritoneal dialysis compared with hemodialysis in the treatment of end-stage renal disease.

Whether to use peritoneal dialysis (PD) or hemodialysis (HD) is a major decision in terms of clinical outcome and management implications; the final choice is difficult because of the conflicting results of comparisons reported in the literature. A review of studies comparing survival shows either superiority of HD, or superiority of PD, or equivalence of the two techniques, but an analysis of the comparisons as a whole brings to light two clear phases in the survival curves. In the first, residual renal function (RRF) gives PD an advantage, or at least puts it on the same level as HD. In the second phase, the reduction in Kt/V as RRF declines gives PD a potential risk. After a few years of PD treatment a sharp watch is therefore necessary to detect signs of under-dialysis promptly and to shift the patient to HD. In patients without RRF it is more difficult to control hypertension with PD and they are more prone to hyperhydration. Despite a widespread belief in the Eighties that PD was the treatment modality of election for diabetics, HD is in fact preferable in these patients, except younger ones. High-turnover and low-turnover bone lesions are more frequent respectively in HD and PD patients. Anemia is better controlled with PD. Blood lipids and nutritional indices are less well controlled with PD. Despite poor technical survival, the "pool" of patients treated with PD frequently reaches 20-30% because it is indicated as first treatment in a large proportion. PD preserves renal function better than HD and is useful while awaiting renal transplantation, with faster postoperative restoration of diuresis. The quality of life with PD as home treatment is usually better than with HD. In conclusion, dialytic centers should establish an integrated PD/HD programme as the two methods are not competitive but are different tools for the treatment and rehabilitation of uremic patients.

Australia↗
PubMedDate not supplied

[Dialysis in the elderly].

Assuming >/= 75 years old as the age limit to define dialysis in the elderly, the incidence in this group of patients is progressively increasing in most dialysis units, with an annual growth of 8 to 16%, and represents 20 to 33% of the overall population being affected. The prevalence of the elderly dialysis group is also high, 14 to 20%, in the main literature casistics. Vascular nephropathies, 13 to 50%, represent the major cause of end-stage renal disease, followed by diabetes, 11 to 37%. First year survival rate is an acceptable 52 to 82%, whereas the fifth year value is on average 20 %, also due to the high baseline mortality in these patients. The death causes are mainly cardiac related and represent 45% of the overall mortality. The main prognostic factors are frequency and severity of comorbid factors, in addition to nutritional indexes that are particularly important in this age group. Dialysis dose and treatment time are not related to mortality. Haemodialysis and peritoneal dialysis complement each other to allow the best results. The survival rate, however, is usually better with haemodialysis, especially in old diabetic patients and after some years of treatment. Vascular access, intradialytic hypotension, cardiopathy, intestinal bleeding and amyloidotic arthropathy represent the more critical aspects of dialysis in the elderly, while the quality of life is sometimes unexpectedly good.

Age Factors↗
PubMedDate not supplied

[Ethical problems in dialysis in elderly patients].

The incidence and prevalence of elderly patients are progressively increasing in most dialysis facilities with consequent medical assistance difficulties and the need to find a suitable care unit. Particularly in this age group, the clinical assessment is often difficult and the selection criteria vary widely, not only from country to country, but also from one dialysis unit to another unit in the same area. The authors discuss some of the more complex arguments for and against dialysis in elderly patients. For some of the more difficult cases, Kantian deontology and its three ethical principles of beneficence, non-maleficence and autonomy can facilitate the decision-making process regarding the acceptance or refusal of the therapy. The central role of the patients themselves, the involvement of the family, the discussion of the individual case within the dialysis team, and the good performance of the pre-dialysis program are particularly important. In certain cases it is possible to actually discontinue the treatment, or not initiate it, by using different arguments in competent or incompetent patients. In conclusion, the difficult choice of whether to treat or turn down an elderly patient must depend exclusively on the medical clinical assessment of each case, whereas economical considerations can incorrectly influence that choice.

Age Factors↗