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Biomedical subjects

A Perna

Publications and source records attributed to A Perna.

At least 19 recordsLinked to original sources

Immunosuppressive treatment for idiopathic membranous nephropathy in adults with nephrotic syndrome.

BACKGROUND: Idiopathic membranous nephropathy (IMN) is the most common form of nephrotic syndrome in adults. The disease shows a benign or indolent course in the majority of patients, with a rate of spontaneous complete or partial remission of nephrotic syndrome as high as 30% or more. Despite this, 30-40% of patients progress toward end-stage renal failure (ESRF) within 5-15 years. OBJECTIVES: To assess the benefits and harms of immunosuppressive treatment for IMN in adults. SEARCH STRATEGY: We searched the Cochrane Renal Group Specialised Register (December 2003), The Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 4, 2003), MEDLINE and Pre-MEDLINE (1966 - December 2003), EMBASE (1980 - December 2003), reference lists of nephrology textbooks, review articles, prospective trial registers, relevant trials and abstracts from nephrology scientific meetings and the internet without language restriction. We also contacted principal investigators of controlled studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs comparing any immunosuppressive interventions for the treatment of IMN in adults. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed and extracted information. Information was collected on method, participants, interventions and outcomes (death, ESRF, proteinuria, serum creatinine, GRF, remission, adverse events). MAIN RESULTS: A total of 18 trials with 1025 patients were included. No differences were found when we combined data of all treatment categories as a group and compared them with placebo or no treatment. Oral glucocorticoids. No beneficial effect on any of the end points chosen for efficacy was observed. Alkylating agents showed a significant beneficial effect on complete remission (RR 2.37, 95%CI 1.32 to 4.25, P = 0.004) but not on partial remission (RR 1.22, 95%CI 0.63 to 2.35, P = 0.56) or complete or partial remission (RR 1.55, 95%CI 0.72 to 3.34, P = 0.27). Cyclophosphamide treatment resulted in significantly lower rate of discontinuations due to adverse events as compared to chlorambucil (RR 2.34, 95%CI 1.25 to 4.39, P = 0.008). There was no evidence of clinically relevant differences in favour of cyclosporin and there was insufficient data on anti-proliferative agents. REVIEWERS' CONCLUSIONS: This review failed to show any long-term effect of immunosuppressive treatment on patient and/or renal survival. There was an increased number of discontinuations due to adverse events in immunosuppressive treatment groups. Within the class of alkylating agents there is weak evidence supporting the efficacy of cyclophosphamide as compared to chlorambucil. On the other hand, cyclophosphamide had fewer side effects leading to patient withdrawal than chlorambucil.

Adult↗

[Review of nutritional and respiratory support in ALS].

During the evolution of amyotrophic lateral sclerosis (ALS), quality of life and survival of patients are related to respiratory and nutritional status. After diagnosis, a multidisciplinary care has to be promptly organized and coordinated by the referring neurologist. The nutritional and respiratory support imply that neurologists know their specific means of evaluation with their sensitivity and sensibility and be able to recognize clinical risk situations. The informations of patients on assisted-ventilation and nutritional support by using gastrostomy may be done early, precisely and trustfully. Well informed patient's choices must be respected. Nutritional and respiratory supports may be based on recommendations established by the American Academy of Neurology. This review will present and discuss their main aspects in patients with ALS.

Amyotrophic Lateral Sclerosis↗

Paradox of circulating advanced glycation end product concentrations in patients with congestive heart failure and after heart transplantation.

OBJECTIVES: To analyse circulating concentrations of advanced glycation end products (AGEs) in patients with severe congestive heart failure (CHF) and after heart transplantation; to identify the potential contribution of kidney function to plasma AGE concentrations; and to determine whether AGE concentrations and parameters of oxidative stress are interrelated. METHODS AND RESULTS: Circulating N(epsilon)-(carboxymethyl)lysine (CML) and AGE associated fluorescence (AGE-Fl), lipid peroxidation, and glomerular filtration rate (GFR) were measured in a cross sectional study of 22 patients with advanced CHF, 30 heart transplant recipients, and 20 healthy controls. Compared with the controls, the CHF patients had decreased CML (mean (SEM) 467.8 (20.0) ng/ml v 369.3 (22.3) ng/ml, p < 0.01), AGE-Fl (mean (SEM) 302.2 (13.3) arbitrary units v 204.9 (15.7) arbitrary units, p < 0.01), and GFR (p < 0.01). CML was positively related to decreased total protein and serum albumin and negatively to body mass index (p < 0.01). In contrast, in the heart transplant group, impaired GFR was associated with a notable rise of both CML (mean (SEM) 876.1 (53.1) ng/ml, p < 0.01) and AGE-Fl (mean (SEM) 385.6 (26.1) arbitrary units, p < 0.01). A positive relation between CML and serum albumin (r = 0.394, p < 0.05) and lipofuscin (r = 0.651, p < 0.01) was found. CONCLUSIONS: The contrasting concentration of CML and AGE-Fl between patients with CHF and after heart transplantation in the presence of decreased GFR and oxidative stress are explained by lowered plasma proteins in CHF and higher concentrations in heart transplant recipients. In heart transplant recipients, in addition to myocardial inflammatory processes, immunosuppression may be important for enhanced formation of AGEs.

Adolescent↗

The alpha1-antitrypsin/elastase complex as an experimental model for hemodialysis in acute catabolic renal failure, extracorporeal blood circulation and cardiocirculatory bypass.

A modified polyethersulphone graft membrane was loaded with antiproteases, with the aim of reducing the active protease blood concentration during hemodialysis in acute catabolic renal failure or cardiopulmonary bypass. As protease/antiprotease system, elastase and alpha1-antitrypsin were used. The concentration of active elastase in aqueous solutions decreased as function of contact time with the membrane, approaching saturation. A 40% loss of elastase activity was obtained at pH 7.4, which was not due to autolysis, which accounted for 5% of the loss. The highest reduction was achieved at pH 9.0 (25% higher than at pH 7.4). The saturation level of elastase decrease, calculated by means of the Einstein equation, was reached after more than 47 minutes. We speculate that a time reduction might be achieved either increasing the concentration of immobilized antiproteases, or increasing the rate of elastase movement across the membranes by hydraulic, osmotic, or temperature gradients. This technology can be applied to hemodialysis, and in extracorporeal blood circulation to promote elastase release.

Acute Kidney Injury↗

T cell response to N-formylated peptides in humans.

We present the first evidence of a T lymphocyte response to N-formylated peptides in humans. N-formylated peptide sequences from self (mitochondrial) and foreign (microbial) antigens were used to isolate antigen-specific T cell clones from healthy individuals, including a set of monozygotic twins. The observed response differed from that previously described in mouse (CD4(+) phenotype and MHC class II restriction in humans vs. CD8(+) phenotype and class I restriction in mice). These lymphocytes produce substantial amounts of IFN-gamma. They were isolated in only one of the monozygotic twins, which suggests that their expansion in the healthy immune repertoire is independent of the genetic background. Our result will help in assessing the relevance of N-formylated peptide-specific T cells in protection against infections within the human immune system.

Adult↗

The heart in uremia: role of hypertension, hypotension, and sleep apnea.

Cardiovascular disease is the leading cause of morbidity and mortality in end-stage renal disease. Causes include those usually found in the general population, those related to the uremic status, and those related to dialytic treatment. Hypertension, hypotension, anemia, hypoalbuminemia, malnutrition, dyslipidemia, reactive C protein, calcium-phosphate product, dialysis modalities, and hyperhomocysteinemia are discussed extensively. Special emphasis is put on hyperparathyroidism as a traditional toxin. The emergent role of sleep apnea has been confirmed in animal models as well as in humans studied using polysomnography. There are difficulties in diagnosing coronary disease, because angiography is not risk-free, is expensive, and should be reserved for patients having symptoms of heart failure and/or patients having diabetes mellitus, and/or patients entering a transplantation list. This allows patients with coronary disease to undergo coronary artery bypass (preferably) or percutaneous transluminal angioplasty. Patients for whom surgery is not appropriate should be treated using more traditional medical procedures.

Adult↗

Nephrotic edema.

This article starts with a concise synopsis of the history of edema. The role of underfilling, overflow, antidiuretic hormone, and acquaporins is subsequently discussed. Emphasis is given to the use of diuretics in edematous patients. The role and risks of albumin infusion are illustrated. The new hypothesis of pulse reverse osmosis is discussed. The final section deals with the measurement of colloid osmotic pressure in the clinical setting.

Edema↗

Myelin basic protein intramolecular spreading without disease progression in a patient with multiple sclerosis.

A case with stable multiple sclerosis (MS) and T cell responses which initially focused on peptide 16-38 of myelin basic protein (MBP) allowed us to investigate the dynamics of the MBP-specific T cell repertoire and its relationship with disease progression. Epitope mapping experiments and T cell receptor usage of MBP-reactive T cell lines (obtained at four distinct time points over a 7-year period) showed a spreading of the response. Transient expansions and persistence of T cells recognizing different MBP epitopes were also detected. The patient's expanded disability status scale and magnetic resonance imaging lesion load remained stable. Our case shows both persistent self-recognitions and determinant spreading in stable MS. This finding suggests that the relationship between dynamics of self-recognition and disease progression is highly complex.

Adult↗

Global immune disregulation in multiple sclerosis: from the adaptive response to the innate immunity.

Increasing evidences show a global immune disregulation in multiple sclerosis (MS). The possible involvement of myelin and non-myelin (auto-)antigens in the autoaggressive process as well as the disregulation of both adaptive and innate immunity challenge the concept of specific immunotherapy. T cells at the boundary between innate and adaptive immunity, whose immunoregulatory role is becoming increasingly clear, have recently been shown to bear relevance for MS pathogenesis. Global immune interventions (and type I interferons may be considered as such) aimed at interfering with both innate and acquired immune responses seem to be a most promising therapeutic option in MS.

Humans↗

Chronic proteinuric nephropathies: outcomes and response to treatment in a prospective cohort of 352 patients with different patterns of renal injury.

The Ramipril Efficacy in Nephropathy (REIN) study found that angiotensin-converting enzyme (ACE) inhibitors effectively decreased proteinuria, glomerular filtration rate (GFR) decline (DeltaGFR), and incidence of end-stage renal disease (ESRD) in patients with proteinuric chronic nephropathies. In this study, we prospectively investigated the main clinical determinants of progression and response to treatment in the 352 patients enrolled into the REIN study. Mean DeltaGFR (0.56 +/- 0.05 [SEM] versus 0.21 +/- 0.05 mL/min/1.73 m(2)/mo; P = 0.0001) and incidence of ESRD (30% and 10%; P = 0.0001) were more than twice that in patients with proteinuria of 2 g/24 h or greater of protein compared with those with protein less than 2 g/24 h (relative risk [RR], 4.07; 95% confidence interval [CI], 2.20 to 7.52), as well as in patients with hypertension compared with normotension (mean DeltaGFR, 0.48 +/- 0. 05 versus 0.22 +/- 0.05 mL/min/1.73 m(2)/mon; P = 0.0006; ESRD, 25% versus 10%; P = 0.004; RR, 3.18; 95% CI, 1.38 to 7.32). Hypertension at study entry (P = 0.038), greater mean blood pressure on follow-up (P = 0.002), and urinary protein excretion rate (P = 0.0001) were independent predictors of faster DeltaGFR. DeltaGFR was approximately twofold faster in patients with type 2 diabetes than in those with primary glomerular disease (P = 0.002; including immunoglobulin A [IgA] nephropathy, P = 0.009); nephrosclerosis (P = 0.03), adult polycystic kidney disease (APKD), or chronic interstitial nephritis (P = 0.006). Diabetes at study entry (P = 0. 02) and greater mean blood pressure (P = 0.0001) and urinary protein excretion rate (P = 0.0001) on follow-up were independent predictors of faster DeltaGFR. After correction for baseline covariates, diabetes was also associated with an increased risk for progression to ESRD (RR, 2.39; 95% CI, 1.01 to 5.68; P < 0.05). At multivariate analyses, ramipril significantly decreased DeltaGFR (regression coefficient,-0.23 +/- 0.11 [SEM]; P = 0.036) and ESRD (RR, 2.08; 95% CI, 1.21 to 3.57; P = 0.008) in patients with baseline proteinuria of 2 g/24 h or greater of protein, and the renoprotective effect increased for increasing levels of proteinuria. Ramipril decreased DeltaGFR to a similar extent in normotensive and hypertensive patients (-0.14 +/- 0.11 versus -0.14 +/- 0.09) and significantly limited ESRD in hypertensive patients (RR, 2.03; 95% CI, 1.26 to 3. 26; P = 0.004). DeltaGFR was decreased by 42% in primary glomerular disease (P = 0.017), by 35% in IgA nephropathy, and by 37% in nephrosclerosis, but was not improved in type 2 diabetes, APKD, or interstitial nephritis. At multivariate analyses, ramipril significantly slowed DeltaGFR (-0.24 +/-0.08; P = 0.004) and progression to ESRD (RR, 2.32; 95% CI, 1.36 to 3.96; P = 0.002) in patients without diabetes, but not in patients with diabetes, who tended to have a faster DeltaGFR (+0.62 +/- 0.44) on ramipril therapy. In summary, patients with proteinuria of 2 g/24 h or greater of protein, preexisting hypertension, or type 2 diabetes were faster progressors. Greater blood pressure and degree of proteinuria were the strongest determinants of faster GFR decline. The renoprotective effect of ramipril was similar in patients with normotension and hypertension. Hypertensive patients and those with proteinuria of 2 g/24 h or greater of protein, primary glomerular disease, or nephrosclerosis gained the most from ACE inhibitor treatment. During the study period, those with proteinuria less than 2 g/24 h of protein, type 2 diabetes, or polycystic kidney disease did not benefit by treatment to an appreciable extent.

Adolescent↗

ACE genotype and ACE inhibitors induced renoprotection in chronic proteinuric nephropathies1.

UNLABELLED: ACE genotype and ACE induced renoprotection in chronic proteinuric nephropathies. BACKGROUND: Whether angiotensin-converting enzyme (ACE) gene polymorphism affects disease progression and response to ACE inhibitor therapy in nondiabetic proteinuric nephropathies is not clearly established. METHODS: The relationship between insertion/deletion (I/D) genotypes and proteinuria, rate of glomerular filtration rate decline (DeltaGFR)-centrally evaluated by repeated measures of iohexol plasma clearance-and incidence of end-stage renal disease (ESRD) was prospectively evaluated in 212 patients with nondiabetic proteinuric chronic nephropathies enrolled in the Ramipril Efficacy in Nephropathy (REIN) trial, where patients were randomly assigned to ramipril or conventional treatment. RESULTS: The DeltaGFR +/- SEM (-0.38 +/- 0.09 vs. -0.50 +/- 0.08 vs. -0.36 +/- 0.06 mL/min/1.73 m2 per month) and incidence of ESRD (19 vs. 22 vs. 25%) in the three subgroups with the II, ID, and DD genotypes, respectively, were comparable. Of note, DeltaGFR (-0.28 +/- 0.07 vs. -0.43 +/- 0.09 mL/min/1.73 m2 per month) and incidence of ESRD [14% vs. 36%, P = 0.04, RR (95% CI), 2.62 (1.02 to 6.71)] were lower in ramipril than in conventionally treated patients in the DD genotype, but not in the II and ID genotype. Either at univariate (P = 0.04) or at multivariate (P = 0.01) analysis, ramipril significantly predicted a lower incidence of events in DD, but not in II and ID patients. At three months, ramipril decreased proteinuria more effectively in DD (-38.2%) than in the II (-26.7%) or ID (-19.2%) genotype. In DD (but not in II or ID) ramipril-treated patients, a short-term reduction in proteinuria correlated with DeltaGFR over the entire follow-up period (P = 0.02, r = -0.41). CONCLUSIONS: In nondiabetic proteinuric nephropathies, the ACE I/D polymorphism does not predict disease progression, but is a strong predictor of ACE inhibition-associated renoprotection in that proteinuria, DeltaGFR, and progression to ESRD are effectively reduced in patients with the DD, but not in those with the II or ID genotype.

Angiotensin-Converting Enzyme Inhibitors↗

Pretreatment blood pressure reliably predicts progression of chronic nephropathies. GISEN Group.

BACKGROUND: Random, nontimed blood pressure (BP) measurements in the outpatient clinic may fail to provide reliable information on actual daily BP control in renal patients on chronic antihypertensive therapy. METHODS: In a cohort of 163 patients with proteinuric chronic nephropathies followed prospectively with repeated BP and glomerular filtration rate (GFR) measurements, we compared baseline and follow-up pretreatment, morning ("trough," measured by standard procedures, and "0 minutes," measured by an automatic device) and post-treatment (120 minutes) measurements, with BP monitored up to 600 minutes after treatment administration. We then evaluated which BP value most reliably predicted GFR decline (delta GFR) and progression to end-stage renal failure (ESRF) over a median (interquartile range) follow-up of 20 (9 to 25) months. RESULTS: GFR decline was more reliably predicted by systolic as compared with diastolic BP and by pretreatment as compared to post-treatment BP, regardless of the timing and method of measurement, respectively. In particular, at the 120-minute baseline and follow-up measurements, systolic BP had no predictive value in patients with less severe renal insufficiency and baseline diastolic BP, regardless of the level of renal dysfunction. The BP predictive value was remarkably higher in ramipril than in conventionally treated patients. All follow-up-but no baseline-measurements reliably predicted the risk of ESRF in the entire study group. CONCLUSIONS: In patients with progressive chronic nephropathies, systolic BP and pretreatment morning BP measurements are the most reliable predictors of disease outcome and may serve to guide antihypertensive therapy in routine clinical activities and in prospective controlled trials, particularly in patients on angiotensin-converting enzyme inhibitor therapy. Reliability and relevance of single measurements taken at different times after treatment administration are questionable.

Adult↗

Early sequence of cardiac adaptations and growth factor formation in pressure- and volume-overload hypertrophy.

To investigate the time sequence of cardiac growth factor formation, echocardiographic and hemodynamic measurements were performed at scheduled times, and mRNAs for angiotensinogen, prepro-endothelin-1 (ppET-1), and insulin-like growth factor I (IGF-I) were quantified with RT-PCR and localized with in situ hybridization in pigs (fluothane anesthesia) by use of pressure or volume overload (aortic banding and aorta-cava fistula, respectively). Relative peptide formation was also measured by radioimmunoassay. In pressure overload, angiotensinogen and ppET-1 mRNA overexpression on myocytes (13 times vs. sham at 3 h and 112 times at 6 h, respectively) was followed by recovery (12 h) of initially decreased (0.5-6 h) myocardial contractility. In volume overload, contractility was not decreased, the angiotensinogen gene was slightly upregulated at 6 h (6.7 times), and ppET-1 was not overexpressed. IGF-I mRNA was overexpressed on myocytes (at 24 h) in both volume and pressure overload (14 times and 37 times, respectively). In the latter setting, a second ppET-1 overexpression was detectable on myocytes at 7 days. In conclusion, acute cardiac adaptation responses involve different growth factor activation over time in pressure versus volume overload; growth factors initially support myocardial contractility and thereafter induce myocardial hypertrophy.

Adaptation, Physiological↗

T cell response to myelin basic protein before and after treatment with interferon beta in multiple sclerosis.

Studies on the in vivo effects of interferon-beta (IFNbeta) therapy on autoreactive T cells have never been carried out in multiple sclerosis (MS). We investigated the T cell response to myelin basic protein (MBP), before and after IFN-beta therapy, raising MBP-specific T cell lines (TCL) from the peripheral blood of six MS patients with a satisfactory response to the treatment. IFNbeta did not affect the relative frequency and epitope specificity of the TCL. After IFNbeta therapy, the production of interleukin-4 was decreased in MBP-stimulated TCL while the secretion of interferon-gamma was increased in unstimulated TCL. Interleukin-10 and tumor necrosis factor-alpha did not show significant variations. This finding supports recent suggestions about the complexity of the T helper 1/T helper 2 paradigm in MS and other organ-specific autoimmune diseases. In fact, the beneficial effects of IFNbeta do not exclude an immunostimulatory action that may involve potentially autoreactive T cells. This has implications for future treatment options, including combination therapies.

Adult↗

Renoprotective properties of ACE-inhibition in non-diabetic nephropathies with non-nephrotic proteinuria.

BACKGROUND: Stratum 2 of the Ramipril Efficacy in Nephropathy (REIN) study has already shown that in patients with chronic nephropathies and proteinuria of 3 g or more per 24 h, angiotensin-converting enzyme (ACE) inhibition reduced the rate of decline in glomerular filtration and halved the combined risk of doubling of serum creatinine or end-stage renal failure (ESRF) found in controls on placebo plus conventional antihypertensives. In REIN stratum 1, reported here, 24 h proteinuria was 1 g or more but less than 3 g per 24 h. METHODS: In stratum 1 of this double-blind trial 186 patients were randomised to a ramipril or a control (placebo plus conventional antihypertensive therapy) group targeted at achieving a diastolic blood pressure of less than 90 mm Hg. The primary endpoints were change in glomerular filtration rate (GFR) and time to ESRF or overt proteinuria (> or =53 g/24 h). Median follow-up was 31 months. FINDINGS: The decline in GFR per month was not significantly different (ramipril 0.26 [SE 0.05] mL per min per 1.73m2, control 0.29 [0.06]). Progression to ESRF was significantly less common in the ramipril group (9/99 vs 18/87) for a relative risk (RR) of 2.72 (95% CI 1.22-6.08); so was progression to overt proteinuria (15/99 vs 27/87, RR 2.40 [1.27-4.52]). Patients with a baseline GFR of 45 mL/min/1.73 m2 or less and proteinuria of 1.5 g/24 h or more had more rapid progression and gained the most from ramipril treatment. Proteinuria decreased by 13% in the ramipril group and increased by 15% in the controls. Cardiovascular events were similar. As expected, the rate of decline in GFR and the frequency of ESRF were much lower in stratum 1 than they had been in stratum 2. INTERPRETATION: In non-diabetic nephropathies, ACE inhibition confers renoprotection even to patients with non-nephrotic proteinuria.

Adult↗

Endothelin receptors in adult human and swine isolated ventricular cardiomyocytes.

The present study aimed to investigate endothelin-1 (ET-1) receptors in human and swine cardiomyocytes with binding studies using ET(A) and ET(B) selective receptor antagonists (BMS-182874 and BQ-788, respectively). Cell distribution of mRNA expression for ET(A) and ET(B) subtypes was investigated by in situ hybridization using specific cDNA probes. The 1251-ET-1 binding, which reached equilibrium in about 120 min (Kobs = 0.051+/-0.003 min(-1)), was only partially displaceable by the addition of a large excess of ET-1 (about 15% with a half-life of 20 min). In equilibrium binding studies, 125I-ET-1 had a Kd of 0.43+/-0.08 nM and a maximum binding (Bmax) of 42.8+/-6.6 fmol/mg protein. ET(A) and ET(B) receptors are represented in human and swine cardiomyocytes with an 85:15 ratio as indicated by the biphasic pattern of competition of both BMS-182874 and BQ-788. In situ hybridization studies confirmed that myocytes mainly expressed mRNA for ET(A), whereas expression of mRNA for the ET(B) subtype was documented in non-myocyte cells. These results showed that ET-1 binds with high affinity and poor reversibility to specific receptors, in both human and swine isolated ventricular cardiomyocytes, without significant species differences.

Adult↗

Evidence-based medicine and its horizons: a useful tool for nephrologists?

Though the concept of 'evidence-based medicine' (EBM) nowadays has become very popular and even fashionable, its practice is far from being an established reality. There are many reasons why, despite its potential, EBM finds obstacles in expressing its full potential as a tool to better inform health care decisions. Broadly speaking, these obstacles fall into three categories: (i) inadequacy of available information with respect the complexities of health care delivery; (ii) poor quality of clinical research; and (iii) insufficient and inappropriate efforts to promote the uptake of effective interventions in clinical practice. In the first part of the paper, we will discuss: (i) what evidence-based medicine is; (ii) why systematic reviews are the fundamental tool of EBM and what is really special about them; (iii) what are the tools for the practice of EBM; (iv) what its limitations are; and (v) what are the hindrances to its implementation. In the second part, a brief assessment of the state of the art of systematic reviews in nephrology will be presented, with special reference to the activities of the recently launched Cochrane Collaborative Review Group in Renal Diseases.

Evidence-Based Medicine↗