Search PubMed⌕ Search

Biomedical subjects

Mario Plebani

Publications and source records attributed to Mario Plebani.

At least 109 records · Page 6Linked to original sources
PubMed2002

Continuing medical education: a challenge to the Italian Scientific Societies of Laboratory Medicine.

BACKGROUND: In the modern health service, it is no longer acceptable for any clinician or other professional to abstain from continuing education after qualification. This is particularly true in the field of laboratory medicine because of the dramatic changes that have occurred in the organization, number and types of tests, and role of medical laboratories. In Italy, a program for continuing education in medicine (Educazione Continua in Medicina (ECM)) has recently been promoted by the National Government. METHODS: Continuing education (CE) in laboratory medicine should include all educational activities that are pertinent to a person's professional skills, activities, interests, and growth. Continuing education can take many forms. In particular, a variety of programs are available that enable employees to improve their knowledge and skills while reducing their travel and absence from the laboratory. RESULTS: The present paper describes the recent redefinition of the mission, aims and structure of the Scientific Division of the Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC) and the role it plays in making available to all associates a program for continuing education in the field of Laboratory Medicine. CONCLUSIONS: The activation of a national program for continuing education in medicine (ECM) in Italy provides a great opportunity for all professionals of the healthcare sector and for laboratorians, in particular. This educational project offers an unrivalled opportunity for the Italian Scientific Societies of Laboratory Medicine to weave quality improvement into their relationships with associates, thus reappraising their missions and goals.

Accreditation↗
PubMed2002

Cystatin C is a more sensitive marker than creatinine for the estimation of GFR in type 2 diabetic patients.

BACKGROUND: Glomerular filtration rate (GFR) is the best overall index of renal function in health and disease. Inulin and 51Cr-EDTA plasma clearances are considered the gold standard methods for estimating GFR. Unfortunately, these methods require specialized technical personnel over a period of several hours and high costs. In clinical practice, serum creatinine is the most widely used index for the noninvasive assessment of GFR. Despite its specificity, serum creatinine demonstrates an inadequate sensitivity, particularly in the early stages of renal impairment. Recently, cystatin C, a low molecular mass plasma protein freely filtered through the glomerulus and almost completely reabsorbed and catabolized by tubular cells, has been proposed as a new and very sensitive serum marker of changes in GFR. This study was designed to test whether serum cystatin C can replace serum creatinine for the early assessment of nephropathy in patients with type 2 diabetes. METHODS: The study was performed on 52 Caucasian type 2 diabetic patients. Patients with an abnormal albumin excretion rate (AER) were carefully examined to rule out non-diabetic renal diseases by ultrasonography, urine bacteriology, microscopic urine analysis, and kidney biopsy. Serum creatinine, serum cystatin C, AER, serum lipids, and glycosylated hemoglobin (HbA1c) were measured. GFR was estimated by the plasma clearance of 51Cr-EDTA. In addition the Cockcroft and Gault formula (Cockcroft and Gault estimated GFR) was calculated. RESULTS: Cystatin C serum concentration progressively increased as GFR decreased. The overall relationship between the reciprocal cystatin C and GFR was significantly stronger (r = 0.84) than those between serum creatinine and GFR (r = 0.65) and between Cockcroft and Gault estimated GFR and GFR (r = 0.70). As GFR decreased from 120 to 20 mL/min/1.73 m2, cystatin C increased more significantly that serum creatinine, giving a stronger signal in comparison to that of creatinine over the range of the measured GFR. The maximum diagnostic accuracy of serum cystatin C (90%) was significantly better than those of serum creatinine (77%) and Cockcroft and Gault estimated GFR (85%) in discriminating between type 2 diabetic patients with normal GFR (>80 mL/min per 1.73 m2) and those with reduced GFR (<80 mL/min/1.73 m2). In particular, the cystatin C cut-off limit of 0.93 mg/L corresponded to a false-positive rate of 7.7% and to a false-negative rate of 1.9%; the serum creatinine cut-off limit of 87.5 micromol/L corresponded to a false-positive rate of 5.8% and to a false-negative rate of 17.0%. CONCLUSIONS: Cystatin C may be considered as an alternative and more accurate serum marker than serum creatinine or the Cockcroft and Gault estimated GFR in discriminating type 2 diabetic patients with reduced GFR from those with normal GFR.

Aged↗
PubMed2002

Histamine-induced cytokine production and ICAM-1 expression in human conjunctival fibroblasts.

PURPOSE: Conjunctival fibroblasts stimulated with histamine (H) may be directly involved in the inflammatory and remodeling processes of chronic allergic conjunctival diseases. METHODS: Proinflammatory cytokine and growth factor production, and the expression of intercellular adhesion molecule-1 (ICAM-1) were studied in conjunctival fibroblast cultures challenged with different concentrations of H (from 10(-9) M to 10(-) (4) M). Interleukin (IL)-1, IL-4, IL-6, IL-8, tumor necrosis factor-alfa (TNF-alpha), fibroblast growth factor (FGF), epidermal growth factor (EGF) and transforming growth factor-beta (TGFbeta-1) were measured in supernatants. ICAM-1 expression was evaluated by a fluorescence activated cell sorter (FACS). Inhibitory effects of the H-1 antagonists (antiH): emedastine, levocabastine, and azelastine, and of the antiH-2, cimetidine, on H-stimulated fibroblasts were evaluated by measuring both cytokines in supernatants and the cellular expression of ICAM-1. RESULTS: Histamine increased the production of IL-1, IL-6 and IL-8, and ICAM-1 expression. TNF-alpha, IL-4 and growth factor production were not modified by histamine. The antiH-1, emedastine, significantly reduced H-induced production of IL-1, IL-6 and IL-8, while azelastine reduced only IL-1. Levocabastine and cimetidine were less effective. The histamine-induced increase in ICAM-1 expression was inhibited by emedastine but not by azelastine and levocabastine. CONCLUSIONS: Histamine has pro-inflammatory effects on conjunctival fibroblasts, inducing the production of cytokines and the expression of ICAM-1. Emedastine significantly reduced cytokine and ICAM-1 expression from H-stimulated fibroblasts. Conjunctival fibroblasts may contribute to the maintenance of inflammation in chronic allergic diseases.

Cells, Cultured↗
PubMed2002

Clinical significance of cytokine determination in synovial fluid.

Cytokines are a complex family of small regulatory proteins able to mediate intercellular communication and play a crucial role in immunologic and inflammatory reactions. Many reports have demonstrated that some cytokines, in particular tumor necrosis factor alpha (TNFalpha) and interleukin (IL)-1beta, IL-6, and IL-8, so-called proinflammatory, may have a major role in the pathogenesis of joint diseases. Thus, high levels of these substances have been found in inflammatory arthropathies, in particular in those characterized by a more aggressive and destructive outcome, such as rheumatoid arthritis, gout, and infectious arthritis. In keeping with their role, the determination of cytokines in synovial fluid may be proposed for clinical purposes, including diagnostic and prognostic assessments. Furthermore, as some of these cytokines may reflect disease activity, their determination may also be useful in the evaluation of therapy.

Biological Assay↗
PubMed2002

Protein turnover, lipolysis, and endogenous hormonal secretion in critically ill children.

OBJECTIVES: The catabolic state is a major contributor to morbidity and mortality of critical illness and may be related to endocrine changes. We studied whether protein and lipid turnover correlate with insulin and growth and thyroid hormone plasma levels in critically ill infants. DESIGN: Prospective clinical study. SETTING: Pediatric intensive care unit. PATIENTS: Twelve critically ill children and ten age-matched controls. MEASUREMENTS: We measured lipolysis and protein turnover by infusing albumin-bound uniformly 13C palmitic acid and 2H3-leucine for 3 hrs and 2H5-glycerol for 5 hrs to critically ill infants. Simultaneously, we measured serum growth hormones, insulin, C-peptide, thyroid-stimulating hormone, T4, T3, albumin, retinol binding protein (RBP), and prealbumin. Hormone and serum protein levels were also measured in six children when recovered from critical illness. Ten healthy age-matched children served as controls for hormone serum levels comparison. RESULTS: Palmitic acid and glycerol turnover were 5.6 +/- 2.2 micromol/kg/min and 12.2 +/- 7.3 micromol/kg/min, respectively, whereas alpha-ketoisocaproic turnover was 4.9 +/- 2.8 micromol/kg/min. Alpha-ketoisocaproic turnover positively correlated (R = 0.7, p = .03) with duration of pediatric intensive care unit admission and with prealbumin and RBP serum levels (R = 0.9, p = .001). Insulin-like growth factor binding protein (IGFBP)-2 was significantly higher and IGFBP-3 was significantly lower in critically ill children (p = .03 and p = .04 vs. recovery phase, respectively). No other hormonal differences were found. Serum albumin was significantly lower in sick children. We found a significant correlation between prealbumin and RBP and IGFBP-3 (R = 0.6, p = 0.03 and R = 0.6, p = .04, respectively). Alpha-ketoisocaproic turnover positively correlated with IGFBP-1 (R = 0.79, p = .01) and did not correlate with insulin-like growth factor I (R = -0.5, p = .15 [not significant]) No other correlations were found. Lipid turnover measurements did not correlate with any endogenous hormone levels or with duration of critical illness. CONCLUSION: Protein turnover but not lipolysis correlated with a persisting critically ill condition, serum prealbumin, RBP, and plasma IGFBP-1.

C-Peptide↗
PubMed2002

Putative pancreatic cancer-associated diabetogenic factor: 2030 MW peptide.

INTRODUCTION: Pancreatic adenocarcinoma causes diabetes mellitus by releasing factors interfering with glucose metabolism. AIMS: We verified in isolated rat hepatocytes the molecular weight (MW) of the fraction from pancreatic cancer cell conditioned media (CM) that altered glucose metabolism and ascertained, using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis, whether there is any common peptide in CM and in the sera of patients with pancreatic cancer. METHODOLOGY: Sera was obtained from patients with pancreatic cancer ( n = 14) and chronic pancreatitis ( n = 9) and healthy control subjects ( n = 10). Conditioned medium (CM) was obtained from the following cell lines: MIA PaCa 2, PSK-1, PANC-1, and CAPAN-1. Two fractions (MW of less than 30,000 Da and less than 10,000 Da) were obtained from patients' sera, from CM, and from non-CM (NCM) after two-step ultrafiltration. Rat hepatocytes were incubated with CM and NCM. The peptide profile of patients' sera, CM, and NCM were analyzed using MALDI-MS. RESULTS: In rat hepatocytes, glucose metabolism was impaired by CM from all the pancreatic cancer cell lines and by CM with an MW of less than 10,000 Da. Two peptides (m/z 2030 and 2726) were found in CM and patients' sera. Only the peptide at m/z 2030 was found to be associated with the presence of diabetes. CONCLUSION: A peptide at m/z 2030 may be a putative pancreatic cancer-associated diabetogenic factor.

Adult↗
PubMed2002

Retrovirus-mediated herpes simplex virus thymidine kinase gene transfer in pancreatic cancer cell lines: an incomplete antitumor effect.

INTRODUCTION: The transfer of drug-susceptible (suicide) genes to tumor cells by retroviral or adenoviral vectors is a novel approach to the treatment of human tumors. AIMS: To ascertain the antitumor effect of retroviral transduction of the pancreatic cancer cell lines MIA PaCa 2, CAPAN-1, PANC1, and PSN1 with the herpes simplex virus thymidine kinase (HSV-TK) gene. METHODOLOGY: The vector carried a neoselectable marker gene, the human interleukin-2 gene, an internal ribosome entry coding site, and the region coding HSV-TK. RESULTS: Twenty micromoles or less of ganciclovir did not modify nontransduced TK- cell growth, whereas > or =100 micromol completely inhibited TK- cell growth, indicating that this dosage is cytotoxic per se. The 4 TK- and the 4 transduced cell lines were treated daily with 0.001, 0.01, 0.1, 1, 10, and 20 micromol of ganciclovir for 13 days. CAPAN-1 cell growth was completely inhibited by 0.1 micromol of ganciclovir; higher doses were required to kill PANC1 (10 micromol) and PSN1 (20 micromol). MIA PaCa 2 cell growth decreased following a 20-micromol ganciclovir dosing. The bystander effect was great in the CAPAN-1 cell line and moderate in PANC1; no bystander effect was recorded in MIA PaCa 2 and PSN1 cell lines. CONCLUSION: Gene therapy with HSV-TK for pancreatic cancer seems effective in only a limited number of tumor-derived cell lines, and this limits its application in vivo.

Animals↗
PubMed2002

Predictive value of amniotic fluid cystatin C levels for the early identification of fetuses with obstructive uropathies.

OBJECTIVE: To compare the diagnostic accuracy of cystatin C with that of creatinine in discriminating renal function in fetuses without ultrasononographic evidence of renal malformations from those with obstructive uropathies. DESIGN: Prospective, observational cohort study. SETTING: Prenatal morphologic and functional evaluation of fetal obstructive uropathies throughout pregnancy. POPULATION: A total of 96 healthy pregnant women at different stages of pregnancy, without any pregnancy-related maternal disease. Eighty-one pregnant women without clinical and ultrasonographic evidence of any fetal anomaly, confirmed at birth, were defined as controls; 15 pregnant women with various fetal obstructive uropathies, evidenced by repeated ultrasound examinations and confirmed at birth, were defined as cases. METHODS: Creatinine was measured by a kinetic Jaffe picric acid method and cystatin C by a nephelometric immunoassay. Variables were analysed by applying conventional statistical tests; the non-parametric receiver operating curves (ROC) analysis was used to evaluate the diagnostic efficiencies of the biochemical markers. MAIN OUTCOME MEASURES: Incidence of confirmed, diagnosed, neonatal obstructive uropathy by measuring baseline levels of cystatin C and creatinine in amniotic fluid. RESULTS: Baseline levels of cystatin C in amniotic fluid were significantly higher (P = 0.0015) among cases than in controls with comparable gestational age; no significant difference was found for creatinine levels (P = n.s.). The maximum diagnostic accuracy of serum cystatin C in discriminating controls from fetal uropathies was 96%, while that of creatinine was 62%. CONCLUSION: Cystatin C may be considered a sensitivebiochemical marker for the early identification of fetuses with obstructive uropathies.

Adult↗
PubMed2002

Plasma antidiuretic hormone levels in children with spina bifida.

PURPOSE: Urological management of spina bifida patients is controversial. The goals of therapy of neurogenic bladder are continence, prevention of infections and preservation of urinary tract. Desmopressin has been recently used in a spina bifida population that is dry during the day (daytime continence was achieved with clean intermittent catheterization and anticholinergics) but wet at night. The aim of this study was to assess plasma antidiuretic hormone (ADH) levels in these children. MATERIALS AND METHODS: The study included 24 patients, 11 males and 13 females (mean age 6.4 years) referred to the Spina Bifida Centre of the Catholic University of Rome, and 57 normal age-matched controls. Morning (07.30-08.00 h) plasma ADH levels were measured using a specific radioimmunoassay. RESULTS: Plasma ADH levels (normal range 5-11 microg/l) did not differ between spina bifida population and healthy controls. Serum ADH had a mean of 6.8 microg/l in affected children and a mean of 7.4 microg/l in the controls. CONCLUSION: We conclude that the use of desmopressin in children with spina bifida should be reserved only in patients with decreased secretion of ADH, or may be useful in patients with persistent nocturnal incontinence to reduce night wetting. Therefore, research with a larger population is needed.

Child↗
PubMed2002

Erythrocyte sedimentation rate: use of fresh blood for quality control.

The erythrocyte sedimentation rate (ESR) remains the most widely used laboratory test for monitoring the course of infections, inflammatory diseases, and some types of cancer. Several test methods have been developed recently, and as a result the safety and reliability of ESR testing procedures have improved. The method recommended by the International Council for Standardization in Haematology and the National Committee for Clinical Laboratory Standards for ESR measurement is based on the traditional Westergren method, using EDTA-anticoagulated samples without dilution. In clinical laboratories, reliable methods for calibration and the use of appropriate control materials are requiredfor monitoring the accuracy and precision of the routine method. We describe and evaluate a procedure for achieving the daily quality control of ESR and for establishing the limits of agreement between working and reference methods. Data from routine patient samples were used to calculate the daily cumulative mean and to monitor its reproducibility over time. Finally, to monitor analytic performance, a comparison was made between results from the measurement of ESR in specimens stored at 4 degrees C for 24 hours and results obtained in fresh samples.

Anticoagulants↗
PubMed2002

Determination of the length of sedimentation reaction (erythrocyte sedimentation rate) in non-anticoagulated blood with the Microtest 1.

The erythrocyte sedimentation rate (ESR), now more appropriately referred to as the "length of sedimentation reaction in blood (LSRB)", remains the most widely used laboratory test for monitoring the course of infections, inflammatory diseases and some types of cancer. Thanks to the several recently developed methods for the measurement of this reaction, the safety and reliability of LSRB testing procedures have improved. The method for LSRB measurement recommended by the International Council for Standardization in Hematology (ICSH) and the National Committee for Clinical Laboratory Standards (NCCLS) is based on the traditional Westergren method, using EDTA-anticoagulated samples. The present paper describes and evaluates a procedure for LSRB measurement with a new manual system, the Microtest 1, which requires only 30 microl of blood and is optimal for pediatric use. Microtest 1 results correlated satisfactorily with the ICSH recommended method (r=0.88, 95% CI 0.84-0.91; y=3.45+0.85x), had no significant bias (2.15, 95% CI -0.32-4.63) and had an imprecision of less than 7% for the reference range values. In addition, the results obtained with the Microtest 1 in "native" whole blood were comparable with those obtained with the reference method in K3EDTA and sodium citrate-anticoagulated specimens; (bias = 1.19, 95% CI -1.78 to 4.16 for K3EDTA-anticoagulated samples and bias = 2.43, 95% CI -0.58 to 5.44 for sodium citrate-anticoagulated samples).

Adult↗
PubMed2002

Errors in laboratory medicine.

BACKGROUND: The problem of medical errors has recently received a great deal of attention, which will probably increase. In this minireview, we focus on this issue in the fields of laboratory medicine and blood transfusion. METHODS: We conducted several MEDLINE queries and searched the literature by hand. Searches were limited to the last 8 years to identify results that were not biased by obsolete technology. In addition, data on the frequency and type of preanalytical errors in our institution were collected. RESULTS: Our search revealed large heterogeneity in study designs and quality on this topic as well as relatively few available data and the lack of a shared definition of "laboratory error" (also referred to as "blunder", "mistake", "problem", or "defect"). Despite these limitations, there was considerable concordance on the distribution of errors throughout the laboratory working process: most occurred in the pre- or postanalytical phases, whereas a minority (13-32% according to the studies) occurred in the analytical portion. The reported frequency of errors was related to how they were identified: when a careful process analysis was performed, substantially more errors were discovered than when studies relied on complaints or report of near accidents. CONCLUSIONS: The large heterogeneity of literature on laboratory errors together with the prevalence of evidence that most errors occur in the preanalytical phase suggest the implementation of a more rigorous methodology for error detection and classification and the adoption of proper technologies for error reduction. Clinical audits should be used as a tool to detect errors caused by organizational problems outside the laboratory.

Blood Transfusion↗
PubMed2002

Diagnostic value of plasma cystatin C as a glomerular filtration marker in decompensated liver cirrhosis.

BACKGROUND: Plasma creatinine concentration and calculated creatinine clearance are of limited value as glomerular filtration rate (GFR) markers in patients with decompensated liver cirrhosis. We assessed plasma cystatin C as an indicator of GFR in such patients. METHODS: We studied 36 patients with decompensated liver cirrhosis and 56 noncirrhotic controls, both groups including individuals with normal and impaired renal function. GFR was measured in all individuals by inulin clearance, with values <72 mL x min(-1) x 1.73 m(-2) considered decreased. We measured cystatin C and creatinine in plasma and calculated (from plasma concentrations) and measured creatinine clearances, using for them decision points of 1.25 mg/L, 115 micromol/L, and 72 and 72 mL x min(-1) x 1.73 m(-2), respectively. RESULTS: Plasma cystatin C concentrations were similar in controls and cirrhotics and, at the usual cutpoint, could detect decreased GFR with similar sensitivities in the two groups (73% and 88%, respectively). Serum creatinine was markedly lower in cirrhotics and remained mostly within the reference interval at all GFR values; the diagnostic sensitivity of creatinine was much lower in cirrhotics than in controls (23% vs 64%). Lower diagnostic sensitivity was also observed for calculated creatinine clearance (53% vs 100% in controls), whereas similar sensitivities were found for measured creatinine clearance (86% and 81%) in controls and cirrhotics, respectively. ROC analysis showed that all four variables had similar diagnostic accuracies in cirrhotic patients. However, it also revealed that good diagnostic accuracies for plasma creatinine and calculated creatinine clearance can be obtained only if reference intervals different from those used for the general population are adopted. CONCLUSIONS: Plasma cystatin C concentration is an accurate GFR marker in cirrhotic patients. Plasma creatinine concentration and calculated creatinine clearance are of no practical value, as their reference values vary with the severity of the liver disease.

Adult↗
PubMed2002

Performance of a revised cardiac troponin method that minimizes interferences from heterophilic antibodies.

BACKGROUND: Recent guidelines for use of cardiac troponin to detect cardiac damage and for cardiovascular risk stratification have made increasingly sensitive troponin assays important. Troponin assays continue to be plagued by interferences caused by heterophilic antibodies (HAs). We evaluated the performance of a revised cardiac troponin I (cTnI) assay designed to have increased analytical sensitivity and to minimize the effect of HAs. METHODS: The revised Dade Behring Dimension cTnI assay was evaluated according to NCCLS EP5-A at five institutions. Plasma samples from 14 309 patients were assayed by the original Dimension cTnI assay. To identify samples that may have interfering HAs, samples with values >1.4 microg/L were reanalyzed on the Dade Behring Stratus CS cTnI assay. Samples with possible interfering antibodies were also analyzed before and after selective absorbance studies on the revised Dade Behring Dimension cTnI assay. RESULTS: The limit of quantification in the revised method was 0.1 microg/L with imprecision (CV) of 11-17% at 0.1 microg/L. Values correlated well with the Stratus CS cTnI method: revised = 1.06(original) + 0.01; r = 0.98, S(y/x) = 0.25 microg/L). Falsely increased results consistent with myocardial infarction by the original Dimension cTnI assay and presumably attributable to HAs were identified in 0.17% of all patients with samples submitted for cTnI analysis. The revised Dimension cTnI assay eliminated the interference in 17 of 25 samples identified and greatly decreased the interference in the other 8. CONCLUSIONS: The revised Dimension cTnI method greatly minimizes the effect of interfering HAs. It also exhibits analytical performance characteristics consistent with recent guidelines for use of this assay to detect cardiac damage.

Adolescent↗