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Biomedical subjects

Y Berland

Publications and source records attributed to Y Berland.

At least 19 recordsLinked to original sources
PubMed2005

Elevation of circulating endothelial microparticles in patients with chronic renal failure.

BACKGROUND: Chronic renal failure patients are at high risk of cardiovascular events and display endothelial dysfunction, a critical element in the pathogenesis of atherosclerosis. Upon activation, the endothelium sheds microparticles, considered as markers of endothelial dysfunction that also behave as vectors of bioactive molecules. AIM: To measure plasma levels of endothelial microparticles (EMPs) in chronic renal failure patients (CRF), either undialyzed or hemodialyzed (HD), and to investigate the ability of uremic toxins to induce EMP release in vitro. METHODS: Circulating EMPs were numerated by flow cytometry, after staining of platelet-free plasma with phycoerythrin (PE)-conjugated anti-CD144 (CD144+ EMP) or anti-CD146 (CD146+ EMP) monoclonal antibodies. Platelet MP (CD41+ PMP), leukocyte MP (CD45+ leukocyte microparticles (LMP)), and annexin-V+ MPs were also counted. In parallel, MPs were counted in supernatant of human umbilical vein endothelial cells incubated with uremic toxins [oxalate, indoxyl sulfate, p-cresol, and homocysteine (Hcy)], at concentrations found in patients. RESULTS AND CONCLUSIONS: CD144+ EMP and CD146+ EMP levels were significantly higher in CRF and HD patients than in healthy subjects. Furthermore, annexin-V+ MPs were elevated in both groups of uremic patients, and CD41+ PMP and CD45+ LMP were increased in CRF and HD patients, respectively. In vitro, p-cresol and indoxyl sulfate significantly increased both CD146+ and annexin-V+ EMP release. Increased levels of circulating EMP in CRF and HD patients represent a new marker of endothelial dysfunction in uremia. The ability of p-cresol and indoxyl sulfate to increase EMP release in vitro suggests that specific uremic factors may be involved in EMP elevation in patients.

Adult↗
PubMed2004

Kelley-Seegmiller syndrome due to a new variant of the hypoxanthine-guanine phosphoribosyltransferase (I136T) encoding gene (HPRT Marseille).

A patient with hyperuricaemia and gouty arthritis due to a new variant of hypoxanthine-guanine phosphoribosyltransferase is described. The mutation (I136T, HPRT Marseille) is in the phosphoribosylpyrophosphate-binding region of the gene and leads to almost total loss of enzyme activity in erythrocytes, with 5% in lymphocytes. Nevertheless, the patient showed no neurological abnormality.

Arthritis, Gouty↗
PubMed2003

Comparative study on two kidney graft rinsing and preservation solutions in terms of the post-transplantation risk of delayed graft function and cost.

OBJECTIVE: To determine whether Belzer solution (Viaspan, Bristol-Myers Squibb, Brussels, Belgium), which is more expensive than Eurocollins solution, was better at preventing delayed graft function (DGF) and whether it was cost-effective as it could potentially reduce post-transplantation complications. METHOD: The risk of occurrence of complications associated with the use of these two rinsing and preserving solutions was estimated from a survey of 106 patients undergoing renal transplantation between 1 January 1993 and 31 March 1998. Both efficacy and adverse outcomes were recorded along with the costs directly associated with the transplantation procedure in the hospital setting: hospitalization, rinsing and preserving solutions, medical and technical interventions and diagnostic tests. RESULTS: For the 45 kidney grafts rinsed and preserved with Eurocollins (strategy S1: n1 = 45) the cost/graft was estimated at 40 euros. With Viaspan (strategy S2: n2 = 61) the corresponding cost/graft was 424 euros. Logistic regression analysis showed that Viaspan was better than Eurocollins solution (ebeta = 0.437; P = 0.05) in preventing DGF. Overall, S2 was less expensive than S1, from the hospital's perspective. The mean difference per patient was 278 euros, which amounts to a saving of 2% of the total cost per renal transplantation. For rinsing and preserving kidney grafts Belzer solution is therefore preferable to Eurocollins solution.

Adenosine↗
PubMed2003

[Review of quality of life instruments used in end-stage renal disease].

Health related quality of life (HRQOL) indicators take into account the personal perception of health, and are proposed as an alternative for efficacy indicators in medical and therapeutic decision making. They provide, due to elaboration and validation of a questionnaire, a standardised assessment of the health status perception. This paper provides a review of a variety of HRQOL instruments developed for patients suffering end-stage renal disease (ESRD). Generic instruments are designed to be applicable in general population and disease-targeted instrument are potentially more sensitive to the characteristics of a specific population. Among HRQOL instruments, we found 4 generic questionnaires (the Sickness Impact Profile, the SF 36, the Nottingham Health Profile and the EQ-5D), 3 disease-targeted questionnaires developed for ESRD patient undergoing dialysis (the Kidney Disease Quality of Life instrument, the Kidney Disease Questionnaire and the Choice Health Experience Questionnaire), 1 questionnaire specific for ESRD patients (the HRQOL questionnaire), and 2 specific disease-targeted instruments for renal transplant (the Kidney Transplant Questionnaire and the ESRD Symptom Checklist-Transplantation Module). In France, very few studies on the quality of life of ESRD patients were published; no specific questionnaire validated in French is yet published.

Humans↗
PubMed2001

Human hypertension caused by mutations in WNK kinases.

Hypertension is a major public health problem of largely unknown cause. Here, we identify two genes causing pseudohypoaldosteronism type II, a Mendelian trait featuring hypertension, increased renal salt reabsorption, and impaired K+ and H+ excretion. Both genes encode members of the WNK family of serine-threonine kinases. Disease-causing mutations in WNK1 are large intronic deletions that increase WNK1 expression. The mutations in WNK4 are missense, which cluster in a short, highly conserved segment of the encoded protein. Both proteins localize to the distal nephron, a kidney segment involved in salt, K+, and pH homeostasis. WNK1 is cytoplasmic, whereas WNK4 localizes to tight junctions. The WNK kinases and their associated signaling pathway(s) may offer new targets for the development of antihypertensive drugs.

Amino Acid Sequence↗
PubMed2001

TT virus infection: prevalence of elevated viraemia and arguments for the immune control of viral load.

BACKGROUND: The most recent polymerase chain reaction (PCR) detection protocols for the TT virus (TTV) permit one to identify the presence of viral DNA in the serum of a majority of healthy individuals, in the absence of any particular risk factor. This is in contrast with previous epidemiological studies that reported a higher prevalence of TTV infection in populations such as haemodialysis patients (HD), haemophiliacs, intravenous drug users or diabetics. OBJECTIVES: To show that these discrepant results were due to the different sensitivity (number of viral copies detected) of the detection protocols used in initial and more recent epidemiological studies. STUDY DESIGN AND RESULTS: We designed a standardised primary PCR assay that detects only viraemia >5x10(3) to 5x10(4) copies/ml for genotypes 1, 2 and 3, and compared the results of this test with those of a nested PCR assay which is 100-fold more sensitive. Viraemia >5x10(3) to 5x10(4) copies/ml were statistically more frequent in HD patients (54.3%), diabetics (54.7%), and HIV-infected patients with CD4 cells <200/mm(3) (69%) than in blood donors (37%) or HIV-infected patients with CD4 cells >500/mm(3) (33%). CONCLUSIONS: These data suggest a possible relationship between the prevalence of elevated viral loads and the level of immunocompetence of the populations studied, and therefore that of an immune control of TTV viraemia. This corroborates previous findings showing that the stimulation of the immune system by an interferon treatment was able to clear TTV viraemia.

Adult↗
PubMed2001

Tubular lesions and tubular cell adhesion molecules for the prognosis of lupus nephritis.

BACKGROUND: To assess the prognostic value of tubular lesions and cell adhesion molecules' expression, a retrospective study with immunohistochemistry was performed on 152 patients presenting lupus nephritis from January 1985 to December 1999. METHODS: The following clinical parameters were recorded: age, sex, race, time of systemic lupus erythematosus (SLE) diagnosis, time of the biopsy, proteinuria, creatininemia, and renal function at the end of follow-up. All biopsies were re-evaluated according to a tubular grading, an inflammatory grading, the percentage of sclerosed glomeruli, the percentage of crescents, and the current WHO classification. Immunohistochemistry was performed with anti-CD40, anti-CD44, and anti-intercellular adhesion molecule-1 (anti-ICAM-1) antibodies. RESULTS: Patients were 136 women (89.5%) and 16 men with a mean age of 31.2 years +/- 12.8 at the time of biopsy. The mean follow-up period was 94.3 months +/- 64.1. Eighty-eight biopsies (58%) showed various degrees of tubular atrophy. Males (P = 0.001) and tubular grading (P = 0.0001) were linked with renal survival in univariate and multivariate analysis. CD40 (P = 0.01) and ICAM-1 (P = 0.001) tubular expressions were linked with renal survival. ICAM-1 tubular expression provided additional information for the prognosis of the patients with biopsies showing tubular atrophy (P = 0.005) or not (P = 0.05). CONCLUSIONS: Our study shows that tubular lesions are good indicator of lupus nephritis outcome. Furthermore, tubular expression of cell adhesion molecules like ICAM-1 and CD40 also serves to predict the outcome.

Adult↗
PubMed2001

Cystatin C is not more sensitive than creatinine for detecting early renal impairment in patients with diabetes.

This study evaluated serum cystatin C as a potential new marker of glomerular filtration rate (GFR) in 49 patients who had steady-state diabetes with early renal impairment. We determined the correlation between GFR measured by chromium 51-labeled EDTA and levels of serum cystatin C, serum creatinine, serum beta(2)-microglobulin, endogenous creatinine clearance, and Cockcroft formula. Sensitivity and specificity for the diagnosis of renal failure, defined as a GFR less than either 80 or 60 mL/min/1.73 m(2), were calculated by receiver operating characteristic (ROC) curves for creatinine, cystatin C, and beta(2)-microglobulin. Finally, we compared mean values of these three serum parameters in patients grouped according to GFR using the two definitions of renal failure. Correlation coefficients with GFR were -0.77 for serum creatinine level, -0.65 for serum cystatin C level, -0.71 for serum beta(2)-microglobulin level, +0.56 for endogenous creatinine clearance, and +0.69 for Cockcroft formula (all P < 0.001). With a cutoff value of 60 mL/min/1.73 m(2), areas under the ROC curve were 0.972 for beta(2)-microglobulin, 0.925 for cystatin C, and 0.916 for creatinine levels. With a cutoff value of 80 mL/min/1.73 m(2), these were 0.838 for beta(2)-microglobulin, 0.780 for cystatin C, and 0.905 for creatinine levels (P = not significant between parameters). These results were not altered after the exclusion of patients (n = 8) with a serum creatinine level greater than 1.41 mg/dL. When patients were classified into three groups according to GFR (group 1, >80 mL/min/1.73 m(2); group 2, 60 to 80 mL/min/1.73 m(2); group 3, <60 mL/min/1.73 m(2)), mean values of serum parameters in the three groups were statistically different (P < 0.0001) except between groups 1 and 2 for cystatin C and beta(2)-microglobulin. With patients classified into two groups (GFR > or < 80 mL/min/1.73 m(2)), mean values for each parameter were statistically different (P < 0.001). Sensitivity, specificity, and positive and negative predictive values for serum creatinine and serum cystatin C levels were very close for both definitions of renal failure. Serum cystatin C is not better than serum creatinine or serum beta(2)-microglobulin levels for estimating GFR in patients with steady-state diabetes using ROC curves or other validation tests.

Adult↗
PubMed2001

Adenosine and hemodialysis in humans.

BACKGROUND: Infections and hypotension are serious complications that develop during hemodialysis (HD) treatment. Adenosine (ADO), a strong hypotensive and immunosuppressive agent, may participate in these two HD complications, because high concentrations of ADO metabolites are found in dialyzed human plasma. ADO, which is released by endothelial cells, is quickly transformed into inosine (INO) by plasmatic ADO deaminase (ADA) and mononuclear cell ADO deaminase (MCADA). In plasma, the degradation of ADO into INO and its uptake by red blood cells (RBC) are both very rapid, resulting in the short half-life of ADO in blood. METHODS: Using liquid chromatography, we evaluated ADO and INO plasma concentrations before and after HD session. RESULTS: Before the HD session, ADO and INO plasma concentrations were higher in hemodialyzed patients than in controls and in peritoneally dialyzed patients. At the end of the HD session, ADO plasma concentration was increased. ADO plasma concentration for the undialyzed patients was in the same range as that of the controls. Before HD, ADA activity was higher in hemodialyzed patients (559 +/- 349 IU) than in controls (219 +/- 48 IU), and the activity rose during the session (665 +/- 135 IU). ADA activity in the undialyzed patients (222 +/- 80 IU) was in the same range as that of the controls (219 +/- 48 IU). Before the HD session, the MCADA activity (247 +/- 144 IU) was lower than in controls (624 +/- 99 IU). HD did not modify ADO RBC uptake. ADO inhibited mononuclear cell proliferation and interferon-gamma production in humans. Finally, as much as 50 microM INO does not inhibit ADO uptake by RBC and does not modify ADA and MCADA activities. CONCLUSIONS: These data indicate that chronic HD inhibited MCADA activity and increased ADO plasma concentration. Both high ADO plasma concentration and low MCADA activity may be involved in dialysis-induced immune system failure and thereby favor infectious diseases.

Adenosine↗
PubMed2000

Mechanism of calcite crystal growth inhibition by the N-terminal undecapeptide of lithostathine.

Pancreatic juice is supersaturated with calcium carbonate. Calcite crystals therefore may occur, obstruct pancreatic ducts, and finally cause a lithiasis. Human lithostathine, a protein synthesized by the pancreas, inhibits the growth of calcite crystals by inducing a habit modification: the rhombohedral (10 14) usual habit is transformed into a needle-like habit through the (11 0) crystal form. A similar observation was made with the N-terminal undecapeptide (pE(1)R(11)) of lithostathine. We therefore aimed at discovering how peptides inhibit calcium salt crystal growth. We solved the complete x-ray structure of lithostathine, including the flexible N-terminal domain, at 1.3 A. Docking studies of pE(1)R(11) with the (10 14) and (11 0) faces through molecular dynamics simulation resulted in three successive steps. First, the undecapeptide progressively unfolded as it approached the calcite surface. Second, mobile lateral chains of amino acids made hydrogen bonds with the calcite surface. Last, electrostatic bonds between calcium ions and peptide bonds stabilized and anchored pE(1)R(11) on the crystal surface. pE(1)R(11)-calcite interaction was stronger with the (11 0) face than with the (10 14) face, confirming earlier experimental observations. Energy contributions showed that the peptide backbone governed the binding more than did the lateral chains. The ability of peptides to inhibit crystal growth is therefore essentially based on backbone flexibility.

Amino Acid Sequence↗
PubMed2000

Tubular lesions determine prognosis of IgA nephropathy.

To assess the prognostic value of histological classification for renal outcome, we did a multivariate analysis of 194 patients with immunoglobulin A (IgA) nephropathy between 1985 and 1995. We also evaluated semiquantitative scales of tubular lesions and vessel lesions. At the time of the biopsy, 65 patients (33.5%) had chronic renal failure. At the end of the follow-up, 33 patients (17%) required hemodialysis. The mean age of the patients was 37.8 +/-18.9 years with predominance of men (sex-ratio: 3.12). Patients were followed-up for a mean of 43.2 +/- 37.2 months. Univariate analysis showed that hypertension (P < 10(-4)), nephrotic syndrome (P = 0.01), and crescents (P = 0.02) were significant in predicting renal failure, unlike subendothelial topography of IgA deposits (P = 0.05) and proteinuria (P = 0.05). Hematuria was a protective factor (P = 0.03). Multivariate analysis showed that tubular grade 2 (relative risk [RR], 5.5) and tubular grade 3 (RR = 28.8) were the best factors to predict chronic renal failure. The histological classification of Haas was significant in the univariate analysis, but not in the multivariate analysis. Tubular grading predicted renal outcome better than did the other histological parameters.

Adolescent↗
PubMed2000

Effects of low animal protein or high-fiber diets on urine composition in calcium nephrolithiasis.

BACKGROUND: The purpose of this article is to evaluate the impact of low protein and high fiber intakes on risk factors of stone recurrence in idiopathic calcium stone formers (ICSFs). METHODS: Ninety-six ICSFs were randomly assigned a low animal protein diet (< 10% of total energy), a high-fiber diet (> 25 g/day), or a usual diet (control group); all patients were recommended to increase their fluid intake. Their daily urine compositions were analyzed at baseline and at four months. Compliance with dietary recommendations was checked by validated food frequency questionnaires. Compliance with total and animal protein intakes was assessed by 24-hour urea and sulfate outputs, respectively. The nutritional intervention (oral instructions, written leaflet, phoning) and food assessment were carried out by a research dietitian. RESULTS: At baseline, diets and the daily urine composition did not differ between the three groups. At four months, while diets differed significantly, the 24-hour output of calcium and oxalate did not differ significantly within and between groups after adjustment for potential confounders (age, sex, and personal and family history of calcium stones) and baseline values. However, as many as 12 out of 31 ICSFs (95% CI, 22 to 58%) assigned to a low animal protein diet achieved a reduction in the urine urea excretion rate of more than 50 mmol/day and also exhibited a significant decrease in urinary calcium excretion that averaged 1.8 mmol/day. A significant correlation between urea and calcium outputs was observed only among patients with hypercalciuria. CONCLUSIONS: These results show that only ICSFs who markedly decrease their animal protein intake, especially those with hypercalciuria, can expect to benefit from dietary recommendations.

Adult↗