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Biomedical subjects

A Albertazzi

Publications and source records attributed to A Albertazzi.

At least 19 recordsLinked to original sources
PubMed2005

A randomized trial of steroid avoidance in renal transplant patients treated with everolimus and cyclosporine.

In this randomized trial renal transplant recipients were treated with basiliximab, everolimus 3 mg/day, low-dose CsA. At transplantation, patients were randomized to stop steroids at the seventh day (group A) or to continue oral steroids in low doses (group B). Of the 113 patients enrolled, 65 were randomized to group A and 68 to group B. All patients were followed for 2 years. During the study 28 (43%) group A patients required reintroduced corticosteroids. One patient died, in group B. The Graft survival rate was 97% in group A and 90% in group B. There were more biopsy-proven rejections in group A (32% vs 16%; P = .044). The mean creatinine clearance was 54 +/- 21 mL/min in group A vs 56 +/- 22 mL/min in group B. Mean levels of serum cholesterol tended to be lower in group A, but the difference was of borderline significance (191 +/- 91 vs 251 +/- 188 mg/dL; P = .07). Vascular thrombosis (0 vs 5) and pneumonia requiring hospitalization (2 vs 7) tended to be more frequent in group B. Only three cases of CMV infection (1 vs 2) occurred. An immunosuppressive therapy with everolimus and low-dose CsA allows one to obtain excellent renal graft survival and stable graft function at 2 years. Early interruption of steroids in patients treated with this regimen may increase the risk of acute rejection, but neither affects graft survival nor graft function, while possibly reducing the risk of hyperlipemia and vascular thrombosis. About 60% of patients given everolimus and low-dose CsA can definitively stop steroids after 1 week.

Adolescent↗
PubMed2005

Accuracy of eight-polar bioelectrical impedance analysis for the assessment of total and appendicular body composition in peritoneal dialysis patients.

OBJECTIVE: To establish the accuracy of bioelectrical impedance analysis (BIA) for the assessment of total and appendicular body composition in peritoneal dialysis (PD) patients. DESIGN: Cross-sectional study. SETTING: University Nephrology Clinic. SUBJECTS: In all, 20 PD patients and 77 healthy controls matched for gender, age and body mass index. METHODS: Whole-body fat-free mass (FFM) and appendicular lean tissue mass (LTM) were measured by dual-energy X-ray absorptiometry. Resistance (R) of arms, trunk and legs was measured by eight-polar BIA at frequencies of 5, 50, 250 and 500 kHz. Whole-body resistance was calculated as the sum of R of arms, trunk and legs. The resistance index (RI) was calculated as the ratio between squared height and whole-body or segmental R. RESULTS: RI at 500 kHz was the best predictor of FFM, LTM(arm) and LTM(leg) in both PD patients and controls. Equations developed on controls overestimated FFM and LTM(arm) and underestimated LTM(leg) when applied to PD patients. Specific equations were thus developed for PD patients. Using these equations, the percent root mean-squared errors of the estimate for PD patients vs controls were 5 vs 6% for FFM, 8 vs 8% for LTM(arm) and 7 vs 8% for LTM(leg). CONCLUSION: Eight-polar BIA offers accurate estimates of total and appendicular body composition in PD patients, provided that population-specific equations are used.

Adipose Tissue↗
PubMed2004

Clinical evaluation of internal hemodiafiltration (iHDF): a diffusive-convective technique performed with internal filtration enhanced high-flux dialyzers.

AIM: Efficiency in removing middle molecules such as beta2-microglobulin (beta2-MG) is one of the main purposes of modern dialytic therapy. In order to achieve this, techniques requiring complex machines and substitution fluid have been developed over recent years. Alternatively, the internal filtration/back filtration phenomenon can be used. The recent development of a so-called "internal filtration enhanced dialyser" prompted us to compare the removal of beta2-MG together with other small molecules when the dialyser was used either in standard hemodiafiltration (HDF) or internal hemodiafiltration (iHDF). METHODS: Ten stable, anuric, hemodialysis (HD) patients treated by thrice weekly standard bicarbonate HD using low-flux synthetic membrane entered the study. A new high-flux polysulfone dialyser designed with the specific aim of enhancing internal filtration (BS-1.6 UL, 1.6 m2, Toray Industries) was used. Post dilution HDF (2.5 l/hour of substitution fluid, dialysate flow 500 ml/min) was compared with iHDF (dialysate flow 750 ml/min), with blood flow at 300 ml/min. Samples were obtained at the start and at the end of the session in order to measure the % removal of urea, creatinine, uric acid, phosphate and beta2-MG (corrected for total protein concentration). In addition, after 20 min of dialysis the clearances of the same molecules were measured. A mathematical model has been developed for the description of the hydrodynamic phenomena taking place within the dialyser and of fluid filtration across the membrane. RESULTS: No significant differences have been observed in removal rate switching from HDF to iHDF except for beta2-MG removal, which was slightly higher in HDF than in iHDF Phosphate clearance is significantly higher than those obtained with creatinine in both HDF (p<0.005) and iHDF (p<0.01) modalities. The total convection calculated with the model is reduced with respect to HDF only by 24% (4100 ml/h vs. 5400 ml/h on the average). CONCLUSIONS: iHDF is a high flux dialysis method, which, if performed with a dialyser designed to enhance internal filtration, obtains a much higher removal rate in comparison with dialysers in traditional high flux dialysis, as previously reported in the literature. Provided that the dialyser is used on a dialysis machine working with ultra pure dialysate and UF control, this dialyser line can perform reliable internal HDF without the need for replacement solution. Considering the narrow difference in performance observed between iHDF and HDF, and the increasing number (and age) of patients leading to higher dialysis costs, iHDF represents a cost-effective alternative to other diffusive-convective techniques.

Aged↗
PubMed2001

Kidney preservation with university of Wisconsin and Celsior solution: a prospective multicenter randomized study.

BACKGROUND: Although the University of Wisconsin (U.W.) solution continues to be the most commonly used for intra-abdominal organs, a new solution, Celsior, already used for heart and lungs, has been proposed for kidney and liver preservation. The aim of this research was to assess the effect of Celsior as compared with U.W. on immediate graft function and a 2-year follow-up of kidney transplants. METHODS: A prospective multicenter randomized study was designed to evaluate the efficacy of the Celsior solution in the clinical preservation of the kidney. In this report, we present the data collected as of September 2000. One hundred donors were included in the trial resulting in 187 renal transplants. Ninety-nine kidneys were stored in Celsior solution and 88 in U.W. solution. The groups were comparable with regard to donor and recipient characteristics. RESULTS: Delayed graft function occurred in 31.3% of the Celsior group and in 33.9% of the U.W. group (P=n.s.). Mean serum creatinine levels and mean daily urinary output were also comparable. Two year graft survival in kidneys preserved with Celsior was 84% as compared with 75% for U.W.-preserved kidneys without any significant statistical difference. CONCLUSIONS: Our data show that the preservation of kidneys in Celsior solution in a clinical setting is equivalent to that of U.W. solution. When using Celsior during multiple-organ donor harvesting it would be possible to perform an in situ flush of all intra-abdominal and intrathoracic organs with a single cold storage solution.

Adenosine↗
PubMed2001

Liver and kidney foreign bodies granulomatosis in a patient with malocclusion, bruxism, and worn dental prostheses.

Granulomatous reactions caused by foreign bodies have been described in drug abusers, in subjects exposed to occupational pollutants, and more rarely, in association with the use of prosthetic devices. We describe a 62-year-old patient with multiorgan parenchymal granulomatosis caused by inorganic debris of unknown origin. The patient presented with fever, hepatosplenomegaly, progressive cholestasis, and acute renal failure. Liver and kidney biopsies showed the presence of noncaseating epithelioid giant-cell granulomas containing scattered polarizable particles. Similar particles were also present in stools. Studies by innovative scanning electron microscopy and energy-dispersive microanalytical techniques showed that the particles isolated in liver, kidney, and stools were made by feldspars, the main component of porcelain. No occupational or environmental exposure to these materials could be identified in this patient and the only reliable source of the porcelain debris turned out to be constituted by 2 dental bridges evidently worn because of a possible inappropriate construction, malocclusion, and bruxism. The porcelain of the dental prostheses had the same elemental spectrum of the particles isolated from stool specimens and liver-kidney granuloma. After identification of the dental prostheses as the most likely source of ceramic debris, and after their removal, the particles from stool specimens disappeared. The patient was then treated with steroids leading to a remission of the clinical symptoms and a decrease in granulomatous inflammatory reaction in both liver and kidney. This is the first report suggesting that a foreign body systemic granulomatosis can be associated with worn dental prostheses.

Bruxism↗
PubMed2000

Changes in conjugated linoleic acid and its metabolites in patients with chronic renal failure.

BACKGROUND: Conjugated linoleic acid (CLA) is a mixture of isomers of linoleic acid with conjugated double bonds that constitutes the most abundant fatty acid with conjugated dienes (CDs) in humans. CLA, erroneously considered in the past as a product of lipoperoxidation, has a dietary origin and has shown to possess anticarcinogenic and anti-atherogenic activity, mainly in animal studies. CLA can be metabolized to conjugated linolenic acid (CD18:3) and to conjugated eicosatrienoic acid (CD20:3) and these metabolites may be implicated in CLA activity. Because of the presence of dyslipidemia and the high incidence of cardiovascular and neoplastic diseases in uremic patients, we evaluated CLA and its metabolites in these patients in order to evaluate their metabolism and site distribution. METHODS: We measured CLA, CD18:3, CD20:3, CD fatty acid hydroperoxides (lipoperoxidation products), and linoleic acid in the plasma, adipose tissue, and red blood cell (RBC) membranes by using high-pressure liquid chromatography in the following groups: (1) 23 chronic renal failure (CRF) patients with creatine clearance (CCr)> 10 mL/min (26.2 +/- 16.7); (2) 21 end-stage CRF patients in conservative treatment with CCr <10 mL/min (6.8 +/- 1.8); (3) 30 hemodialysis (HD) patients; and (4) 30 healthy controls. RESULTS: The incorporation of CLA, CD18:3, and CD20:3 in RBC membranes was significantly reduced in group 1 and was even more reduced in groups 2 and 3. CLA significantly increased both in the plasma and adipose tissue of end-stage CRF patients only. CD18:3 and CD20:3 did not change in the plasma and adipose tissue of any group. No significant changes in linoleic acid and CD fatty acid hydroperoxides were found. CONCLUSIONS: The alterations of CD in CRF patients are not due to lipoperoxidation. The increased levels of CLA in plasma and adipose tissue of end-stage CRF patients may be due either to a reduced metabolization of CLA to CD18:3 and CD20:3, or to an altered site distribution with reduced incorporation in cellular membranes and accumulation in the plasma and adipose tissue. The clinical significance of these changes remains to be investigated.

Adipose Tissue↗
PubMed2000

Influence of different hemodialysis membranes on red blood cell susceptibility to oxidative stress.

Oxidative stress is crucial in red blood cell (RBC) damage induced by activated neutrophils in in vitro experiments. The aim of the study was to evaluate whether the bioincompatibility phenomena occurring during hemodialysis (HD) (where neutrophil activation with increased free radical production is well documented) may have detrimental effects on RBC. We evaluated RBC susceptibility to oxidative stress before and after HD in 15 patients using Cuprophan, cellulose triacetate, and polysulfone membrane. RBC were incubated with t-butyl hydroperoxide as an oxidizing agent both in the presence and in the absence of the catalase inhibitor sodium azide. The level of malonaldehyde (MDA), a product of lipid peroxidation, was measured at 0, 5, 10, 15, and 30 min of incubation. When Cuprophan membrane was used, the MDA production was significantly higher after HD, indicating an increased susceptibility to oxidative stress in comparison to pre-HD. The addition of sodium azide enhanced this phenomenon. Both cellulose triacetate and polysulfone membranes did not significantly influence RBC susceptibility to oxidative stress. Neither the level of RBC reduced glutathione nor the RBC glutathione redox ratio changed significantly during HD with any of the membranes used. The RBC susceptibility to oxidative stress was influenced in different ways according to the dialysis membrane used, being increased only when using the more bioincompatible membrane Cuprophan, where neutrophil activation with increased free radical production is well documented. The alterations found in this study might contribute to the reduced RBC longevity of HD patients where a bioincompatible membrane is used.

Biocompatible Materials↗
PubMed2000

Biofilms invade nephrology: effects in hemodialysis.

Bacteria attach to surfaces and aggregate in a biopolymer matrix to form biofilm. Studies on biofilm have shown its presence in many prosthetic devices used in nephrology as well as in fluid pathways of hemodialysis plants and monitors. Once present, this community of bacteria increases resistance to biocide due to slime production and, as a result, chemical products for dialysis monitor disinfection and descaling procedures do not result in an effective treatment. Ultrapure dialysate is a goal in modern hemodialysis, and ultrafiltration is used to obtain sterile and apyrogen fluids. Microbial colonisation of ultrafilters may occur if, due to inadequate disinfection protocols, membrane is exposed to persistent bacterial contamination, and biofilm is allowed to form and to grow. As more and more data link final dialysate microbial contamination to clinical effects of bioincompatibility from chronic inflammation in dialysis patients, attention has to be focused on possibilities of biofilm avoidance.

Biofilms↗
PubMed1999

Surface antigen expression and platelet neutrophil interactions in haemodialysis.

BACKGROUND: There is increasing evidence to show the clinical implications of membrane biocompatibility in haemodialysis therapy. METHODS: We conducted a cross-over clinical study examining the clinical biocompatibility profile of three derivatised cellulosic membranes obtained by means of different modifications to the cellulose polymer (haemophan, cellulose diacetate, benzyl cellulose) in comparison to the parent polymer (cuprophan) and a reference synthetic membrane (polysulfone). RESULTS: In terms of leukopenia production, derivatised cellulosic membranes were generally intermediate between cuprophan and polysulfone, haemophan being more marked than the other two membranes. Upregulation of CD11b/CD18 molecule on neutrophils was found with all membranes, to a greater extent with the dialyser containing cuprophan. The expression of CD11b/CD18 on monocytes was slightly affected with cuprophan only. The neutrophil and monocyte counts throughout the entire dialysis session showed a much better correlation with the cellular expression of sialyl-Lewis x (CD15s) molecule than with CD11b/CD18 expression. An increased formation of platelet-neutrophil coaggregates occurred at 15 and 30 min during dialysis with all membranes but benzyl cellulose, the increase with cuprophan being higher than with the other membranes. In concomitance with the increase in platelet-neutrophil coaggregation, an increased hydrogen peroxide production by neutrophils occurred, which proved to be significantly higher compared to the unchanged neutrophil hydrogen peroxide production during HD with benzyl cellulose. CONCLUSIONS: Our results demonstrate that derivatised cellulose is associated with a considerable improvement in the clinical biocompatibility profile. Derivatised cellulosic membranes show many similarities but also several significant differences which very likely stem from the different type of structural modification to the cellulose polymer rather than from the degree of hydroxyl group replacement.

Adult↗
PubMed1999

Leukocyte adhesion molecules and leukocyte-platelet interactions during hemodialysis: effects of different synthetic membranes.

Membranes made from synthetic polymers, in general, are considered as being biocompatible membranes and tend to be treated as a homogeneous group. However, all of these membranes have multiple and different characteristics that may contribute to interactions with blood components. As a consequence, the biocompatibility profile of synthetic membranes may vary. In the present cross-over study, we examined by flow cytometry the effects (expressed as % change from predialysis values) of three different synthetic polymers (polysulfone, PSF; polyacrylonitrile-co-sodium methallyl sulfonate, AN69; ethylenevinylalcohol, EVAL) on the expression of leukocyte adhesion molecules (CD11b/CD18, CD15s) and the interactions between leukocytes and platelets under conditions of routine clinical use. For neutrophils, a statistically significant difference was found in CD15s expression for EVAL as compared to AN69 (p<0.05) and in CD11b/CD18 expression for PSF as compared to both EVAL (p<0.01) and AN69 (p<0.05). No difference between membranes was found on the expression of such adhesive molecules on monocytes. Significant differences in platelet-neutrophil (but not in platelet-monocyte) coaggregate formation were observed between PSF and both EVAL (p<0.001) and AN69 (p<0.01). Reactive oxygen species production by neutrophil population during hemodialysis was significantly different between each pair of synthetic polymers (PSF vs EVAL, p<0.001; PSF vs AN69, p<0.001; AN69 vs EVAL, p<0.05). Our data demonstrate that in terms of leukocyte adhesion receptors and platelet-leukocyte interactions, the biocompatibility profile of the synthetic membranes polysulphone, AN69 and EVAL shows many similarities but also several significant differences. Our results support the concept that biocompatibility evaluation of each membrane should be based exclusively on data generated by that membrane in order to avoid errors based on assumptions about group characteristics.

Acrylic Resins↗
PubMed1998

Serum levels of soluble adhesion molecules in chronic renal failure and dialysis patients.

Besides cell-bound adhesion molecules, which are of fundamental importance to a large number of physiological and pathological processes, soluble forms of adhesion molecules have been detected in the circulating blood in recent years. Circulating soluble adhesion molecules appear to be biologically active, and raised levels have been reported in a variety of disorders. In the present study, we used ELISA to measure the serum levels of four soluble adhesion molecules in 23 undialyzed patients with chronic renal failure (CRF), 13 patients on continuous ambulatory peritoneal dialysis (CAPD), 17 on chronic hemodialysis (HD) and 18 healthy controls having a similar mean and distribution of ages. The investigated soluble (s) molecules included intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule 1 (sVCAM-1), sE-selectin and sP-selectin. sICAM-1 was found to be elevated in patients with CRF (p < 0.05), on CAPD (p < 0.02) and HD (p < 0.0001) compared with the controls but levels did not differ between the three patient groups. The higher sVCAM-1 values found in CRF (p < 0.02), CAPD (p < 0.05) and HD (p < 0.0001) as compared to controls again failed to differentiate the three groups of patients. Soluble E-selectin was also raised in the three groups (p < 0.0001) with no difference between them. Increased sP-selectin was found in CRF (p < 0.05), CAPD (p < 0.02) and in HD patients (p < 0.0001) compared to controls, and levels in HD were significantly higher (p < 0.02) than in CRF patients. Predialysis serum molecule levels did not differ between HD patients treated with cuprophan or with polyacrylonitrile dialyzers. HD sessions with both dialyzers had no effect on sICAM-1, while a decrease (p < 0.02) in sP-selectin was found after dialysis with cuprophan. In undialyzed patients with CRF, regression analysis showed a strong linear correlation between serum creatinine and serum levels of each soluble molecule. These results demonstrate that serum levels of soluble adhesion molecules ICAM-1, VCAM-1, E-selectin and P-selectin are elevated in both undialyzed patients with CRF and patients on CAPD or HD. The elevated serum levels of these proteins probably reflect inadequate clearance as well as enhanced synthesis/release.

Adult↗