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Biomedical subjects

M Plebani

Publications and source records attributed to M Plebani.

At least 73 records · Page 4Linked to original sources
PubMed2000

ME-PCR for the identification of mutated K-ras in serum and bile of pancreatic cancer patients: an unsatisfactory technique for clinical applications.

Our aim was to assess the clinical reliability of mutated K-ras detection in serum or bile for the diagnosis of pancreatic cancer using ME-PCR. DNA was extracted from 1 ml serum obtained from 29 patients with pancreatic cancer and 12 control subjects. ME-PCR was optimized using a mixture of normal DNA added with different amounts of mutated DNA. The analysis of sera obtained from the 29 patients and of bile obtained from 11 pancreatic cancer patients demonstrated the presence of mutated K-ras in two (6.9%) and four cases (36%). By contrast K-ras was not amplifiable in any of the 12 serum samples obtained from healthy controls. In conclusion the DNA obtained from pancreatic cancer patients' sera is suitable for K-ras amplification and for the identification of codon 12 point mutations. However ME-PCR alone has an unsatisfactory sensitivity for the detection of pancreatic cancer using serum DNA as starting template.

Adult↗
PubMed2000

Total PSA, free PSA/total PSA ratio, and molecular PSA detection in prostate cancer: which is clinically effective and when?

OBJECTIVES: To ascertain when the serum determination of the free prostate-specific antigen (PSA)/total PSA (fPSA/tPSA) ratio is clinically useful, and whether the identification of PSA or prostate-specific membrane antigen (PSM) mRNA in circulating cells has diagnostic advantages over the determination of their protein product. METHODS: fPSA, tPSA, and the fPSA/tPSA ratio were determined in the sera of 50 men with benign nonprostatic urologic diseases (EPD), 112 patients with prostate cancer (PCa), and 218 with benign prostatic hyperplasia (BPH). mRNA was extracted from the circulating mononuclear cells of 13 EPD samples, 25 PCa samples, and 38 BPH samples. PSA and PSM mRNA signals were identified in these samples by means of reverse transcriptase-polymerase chain reaction. RESULTS: Overall, at a fixed specificity of 95%, the sensitivity of tPSA was 19% and that of the fPSA/tPSA ratio was 40% in distinguishing PCa from BPH. The fPSA/tPSA ratio allowed the discrimination of PCa from BPH with satisfactory sensitivity and specificity when considering patients less than 60 years of age (100% and 95%, respectively). PSA and PSM mRNA were positive in 1 and 7 of 13 EPD samples, 6 and 13 of 25 PCa samples, and 6 and 17 of 38 BPH samples. The Gleason score did not correlate with tPSA, the fPSA/tPSA ratio, PSA mRNA, or PSM mRNA. CONCLUSIONS: The serum determination of the fPSA/tPSA ratio is an excellent index of PCa for subjects younger than 60 years of age; the clinical utility of PSA mRNA identification in circulating cells needs to be validated by large follow-up studies, and the analysis of PSM mRNA seems to be of no clinical interest.

Aged↗
PubMed2000

C-reactive protein and serum amyloid A protein in neonatal infections.

In this study, we examine C-reactive protein (CRP) and serum amyloid protein A (SAA). Although the former is the best known and most commonly used indicator of inflammation, certain considerations underline the inadequacy of CRP determination alone for the early diagnosis of infection. In fact symptoms often precede the CRP elevation. SAA protein comprises a family of polymorphic apolipoproteins produced mainly by the liver, and several studies have stressed its importance in the diagnosis and monitoring of various diseases. Pathological SAA values are often detected in association with normal CRP concentrations. SAA rises earlier and more sharply than CRP. Finally, contrary to CRP, SAA presents the same trend in viral as well as bacterial infections. Although the data available on SAA in neonates are currently very limited, it is possible to postulate a role of primary importance for SAA in the management of neonatal infections.

C-Reactive Protein↗
PubMed2000

High serum cardiac troponin T concentrations in preterm infants with respiratory distress syndrome.

UNLABELLED: In preterm infants with respiratory distress syndrome (RDS), cardiac function is negatively influenced by the severity of the lung disease. On day 2 of life, cardiac troponin T (cTnT), biochemical marker of myocardial injury, was measured in 46 preterm infants (gestational age < or =32 wk), 26 with RDS and 20 without: median (range) 0.38 (0.02-1.57) microg/L vs 0.13 (0.02-0.85) microg/L, respectively. CONCLUSION: High cTnT concentrations in preterm infants with RDS suggest the presence of myocardial damage in this group of high-risk patients.

Female↗
PubMed2000

Anti-inflammatory and antiallergic effects of ketorolac tromethamine in the conjunctival provocation model.

AIM: To study the effect of the topical anti-inflammatory drug, ketorolac, on (1) the clinical allergic reaction induced by the conjunctival provocation test (CPT); (2) the release of tryptase in tears; and (3) the expression of adhesion molecules on the conjunctival epithelium. METHODS: 10 allergic but non-active patients were challenged in both eyes with increasing doses of specific allergen to obtain a positive bilateral reaction and rechallenged, after 1 week, to confirm the allergic threshold dose response. After 2 weeks, a third CPT was then performed bilaterally 30 minutes after topical application of ketorolac in one eye and placebo in the contralateral eye in a double blind fashion. Clinical symptoms and signs were registered 5, 10, 15, and 20 minutes after challenge. The following objective tests were performed: tear tryptase measurement; tear cytology; and conjunctival impression cytology for immunohistochemical expression of ICAM-1 on epithelial cells. RESULTS: Compared with placebo, ketorolac significantly reduced the total clinical score and the itching score in the 20 minutes after challenge (p<0.0005). Tear levels of tryptase were significantly reduced in the ketorolac pretreated eyes compared with placebo (p<0.03). Eosinophils, neutrophils, and lymphocytes in tear cytology were significantly lower in ketorolac treated eyes compared with placebo. A significant difference in the epithelial expression of ICAM-1 was observed between placebo and ketorolac treated eyes (p<0.05). CONCLUSION: Ketorolac proved to be effective in reducing mast cell degranulation, as indicated by significantly decreased tryptase tear levels, as well as the clinical and cytological allergic reaction.

Administration, Topical↗
PubMed2000

CEA mRNA identification in peripheral blood is feasible for colorectal, but not for gastric or pancreatic cancer staging.

OBJECTIVE: It has been suggested that the molecular identification of cancer cells in the circulation may be useful in predicting the presence of micrometastasis in several cancer types. The aim of the present study was therefore to assess the feasibility of CEA mRNA identification in blood for diagnosing and staging colorectal, gastric and pancreatic cancer. METHODS: We studied 16 control subjects, 69 patients with colorectal (CRC), 30 with gastric (GC), 27 with pancreatic cancer (PC) and 8 with benign diseases of the pancreatobiliary tree. At diagnosis CEA mRNA was identified in peripheral blood by means of a RT-PCR procedure. RESULTS: The specificity of this test in control subjects was 94%, and its sensitivity in identifying CRC, GC and PC were 34, 37 and 41%, respectively. False-positive findings were recorded in 25% patients with benign diseases. No association was found between CEA mRNA and stage in patients with GC or PC. In CRC patients, positive CEA mRNA findings were correlated with local spread (chi(2) = 14.6, p<0.01), lymph node (chi(2) = 18.95, p<0.001) and distant metastasis (chi(2) = 11.3, p<0.001). In these cases, CEA mRNA, but not CEA, was entered in stepwise discriminant analysis to classify the presence of lymph node metastasis. CONCLUSIONS: The molecular detection of micrometastasis in the blood by means of CEA mRNA identification is feasible for colorectal, but not for gastric or pancreatic cancer staging. Further studies are needed in order to define the clinical utility of this marker also in follow-up protocols.

Adult↗
PubMed2000

Clinical evaluation of percent free prostate-specific antigen using the AxSYM system in the best analytical scenario.

OBJECTIVE: Percent free prostate-specific antigen (PSA) is a promising tool for prostate cancer (CaP) diagnosis. However, its diagnostic performances have not yet been established. The present study was carried out with the aim of evaluating percent free PSA in the most favourable analytical conditions. MATERIALS AND METHODS: Eighty-eight patients affected by newly diagnosed, untreated, primary CaP, and 169 cases with biopsy-confirmed, untreated, benign prostatic hypertrophy (BPH) were prospectively enrolled. Abbott AxSYM total and free PSA were measured by the same technician using the same instrument and the same reagent batch. RESULTS: Percent free PSA was more effective than total PSA in differential diagnosis between CaP and BPH in every evaluated dose range of total PSA. In cases with total PSA >4 microg/l, percent free PSA could have reduced by about 50% the rate of unnecessary biopsies with a probably still acceptable 93% cancer detection rate. The likelihood of CaP after the determination of percent free PSA was in fact higher than 50% using cut-off points which provide low sensitivity values (i.e. 58% in men aged 50-59 years). CONCLUSIONS: Percent free PSA is superior to total PSA in distinguishing primary CaP from BPH in patients with total PSA between 2 and 30 microg/l and in reducing the rate of unnecessary biopsies in men with total PSA higher than 4 microg/l. However, percent free PSA should be cautiously interpreted in decision making in individual patients since post-test probability is relatively low in men aged 50-70 years.

Aged↗
PubMed2000

Usefulness of EC4 essential criteria for quality systems of medical laboratories as guideline to the ISO 15189 and ISO 17025 documents. European Community Confederation of Clinical Chemistry (EC4) Working Group on Harmonisation of Quality Systems and Accreditation.

Many medical laboratories have made a start with the introduction of quality management systems. However, it is still not clear against which standards such systems should be measured. The existing ISO and CEN standards do not cover essential aspects of medical laboratories. The publication of the EC4 Essential Criteria has stimulated the development of the ISO/Draft International Standard 15189. This standard seems adequate for our type of laboratories. However, it is not easy to read. The EC4 Essential Criteria could well serve as a guide, covering additional aspects, e.g. on total quality management and budget management as required in the EFQM model, that are not (yet) included in the ISO standard. In the present article the EC4 Essential Criteria are cross-referenced with two new international ISO standards, ISO/FDIS 15189 and ISO/FDIS 17025, the latter being the successor of ISO guide 25 and EN 45000. Both new ISO documents are in compliance with the new ISO 9000:2000 standard.

Europe↗
PubMed2000

[The role of biochemical markers of myocardial damage in clinical practice: the diagnosis of infarct and risk stratification. The Intersociety Interdisciplinary Study Group of the ANMCO-SIBioC-SIMeL, Markers of Muocardial Lesions. L'Associazione Nazionale Medici Cardiologi Ospedalieri-Società Italiana di Biochimica Clinica-Società Italiana di Medicina di Laboratorio].

For many years creatine kinase (CK) and CK-MB isoenzymes were used together with the ECG to confirm the presence of myocardial infarction. During the last decade newer cardiac markers have been introduced and immunological test systems developed for their quantification. Among these new markers, a prominent role has emerged for cardiac troponins (T or I). These technological advanced assays have shown greater sensitivity compared to "conventional cardiac enzymes;, thereby identifying patients with small--at times, microscopic--infarcts who would not have met defining criteria for myocardial infarction in an earlier era. Another major advantage shown by both cardiac troponins with respect to "conventional cardiac enzymes" is their ability to predict clinical outcome over a short- or long-term follow-up in patients with acute coronary syndromes, and this appears to be particularly relevant in patients with micronecrosis, who constitute a high-risk subgroup of unstable angina patients. Recently, myoglobin has also been widely applied as a marker. Although lacking in myocardial specificity, it is the earliest marker to show an increase after coronary occlusion. Thus, the combined use of myoglobin and a cardiospecific structural protein such as troponin T or I may prove an attractive strategy for biochemical testing in chest pain patients. With the routine use of these novel cardiac markers, fascinating opportunities are now open in the field of diagnostic classification (making the World Health Organization definition of myocardial infarction obsolete) and risk stratification in chest pain patients; opportunities that were unforeseen in the era of cardiac enzymes. However, the use of these markers has also posed some important questions on: a) the best and most cost-effective diagnostic strategy in chest pain patients; b) the remaining role of cardiac enzymes; c) the therapeutic consequences of a positive test result.

Biochemical Phenomena↗
PubMed2000

External quality assessment of urine analysis in Europe. Results of a round table discussion during the symposium 'From uroscopy to molecular analysis', Seeon, Germany, September 18-20, 1999.

Interlaboratory surveys on urine quantities have only recently been introduced in several European countries. Representatives of 10 European countries exchanged their experiences during an international urinalysis meeting held in September 1999. Although still not mandatory in most areas, more than 5000 laboratories participated in external quality assessment programs in the countries represented. Qualitative (test strips and microscopic morphology) as well as quantitative chemical and immunochemical quantities were included. The maximal allowable deviations are reported as well as methods used to determine target values. Consensus scales up to reference methods were applied. The participants agreed that quality criteria need to be defined separate from those already existing for plasma/serum analytes. Besides higher biological variables and different medical needs, less standardisation of methods to quantify urine constituents was observed as a major cause of higher interlaboratory differences.

Europe↗
PubMed2000

Multicenter evaluation of five assays for myoglobin determination.

BACKGROUND: Lacking assay standardization, different myoglobin methods may produce results that differ significantly. METHODS: A multicenter study was carried out to compare the analytical performance of five commercially available assays for myoglobin measurement. Linearity, imprecision, interferences, and method comparison were studied according to NCCLS guidelines, whereas reference values were determined following IFCC recommendations. RESULTS: The BNA and Opus showed relatively high imprecision (all but one total CV >7.4%). Other assays showed lower CVs, but they varied among laboratories, particularly at a normal myoglobin concentration (Access, 6.0-11%; Hitachi, 3.8-5.8%; Stratus, 3.4-6.5%). Results were lower in anticoagulated samples on the Access, in heparin and citrate samples on the Stratus, and in citrate samples on the BNA and Opus, and increased in heparin and EDTA samples on the Hitachi. Use of separator gel produced results significantly lower (P <0.001) on the Hitachi and higher (P = 0.016) on the Opus. Bilirubin, turbidity, and hemoglobin had no effect on evaluated methods, but rheumatoid factor affected the Access. In method comparisons, high correlation coefficients (>/=0.98) were obtained. The Stratus gave higher results; however, the Access and BNA gave the lowest. The following upper reference limits (microgram/L) for men and women, respectively, were obtained: Access, 70 and 52; BNA, 51 and 49; Hitachi, 67 and 58; Opus, 80 and 50; and Stratus, 86 and 63. CONCLUSION: The possibility of high imprecision and marked disagreement among commercial myoglobin assays should be carefully considered in clinical practice.

Humans↗
PubMed2000

Growth factors and collagen distribution in vernal keratoconjunctivitis.

PURPOSE: To study the extracellular composition of giant papillae in vernal keratoconjunctivitis (VKC) and the expression of growth factors that may stimulate fibrosis. METHODS: Upper conjunctival specimens were obtained by biopsy in 9 patients affected by active tarsal VKC (14 eyes) and 10 normal control subjects. Immunohistochemistry was performed on tissue sections using monoclonal antibodies (mAbs) for collagens I, III, and VII; tumor necrosis factor (TNF)-alpha; transforming growth factor (TGF)-ss1; basic fibroblast growth factor (bFGF); and platelet-derived growth factor (PDGF). The mAbs anti-tryptase, anti-CD4, anti-CD68, and anti-EG2 were used as markers for mast cells, T-helper lymphocytes, macrophages, and eosinophils, respectively. Immunofluorescent double-staining for growth factors and cell markers was performed in VKC tissues. RESULTS: Immunostaining was highly positive for collagens I, III, and VII in the subepithelium of VKC conjunctiva. Image analysis showed a significant increase of staining per tissue area for both collagens I and VII and increased basal membrane length. The number of cells positive for TNF-alpha, TGF-ss, bFGF, or PDGF was significantly higher in VKC tissue than in control samples. Double staining showed that eosinophils and macrophages were the main sources of PDGF and that FGF was expressed by 46% of mast cells. Significant PDGF and FGF staining was observed in the conjunctival epithelium and vascular endothelium of all VKC tissues. CONCLUSIONS: In giant papillae of VKC, the extracellular matrix is characterized by overproduction of collagens. Expression of growth factors in the conjunctiva by resident cells (mast cells, epithelial cells, endothelial cells) and inflammatory cells (macrophages, eosinophils) may contribute to papillae formation and fibrosis evolution in chronic ocular allergic diseases.

Adolescent↗
PubMed1999

The role of cysteine and serine proteases in colorectal carcinoma.

BACKGROUND: Cathepsin B (CATB) and cathepsin L (CATL), which are cysteine proteases, urokinase-(UPA) and tissue-type plasminogen activator (TPA), both serine proteases, and their inhibitor type-1 (PAI-1) are believed to play an important role in colorectal carcinoma (CRC) invasion and metastasis. The objective of this study was to measure CATB, CATL, UPA, TPA, and PAI-1 in the same cancerous tissue (CANCER) and in tissues obtained from a tumor free area (NORMAL) to compare their respective prognostic roles in patients with CRC. METHODS: CANCER and NORMAL samples were obtained from 60 CRC patients undergoing surgery (36 males and 24 females; mean age, 63.8 years [range, 27-85 years]). The antigen concentrations were measured using an enzyme-linked immunoadsorbent assay method. The CANCER tissue also was examined in terms of major histomorphologic parameters such as differentiation, vascular invasion, degree of necrosis, and mucus production. RESULTS: Significantly higher antigen levels were found: 1) in CANCER versus NORMAL (with respect to CATL, UPA, and PAI-1, with significantly lower levels for TPA); 2) in CRC with versus without metastasis (CATB, CATL, and PAI-1); 3) in poorly versus well differentiated CRC (UPA and PAI-1); and 4) in advanced Dukes stages (PAI-1). CATB and CATL significantly correlated with UPA and PAI-1. Finally, CATL (P = 0.0001), UPA (P = 0.006), PAI-1 (P = 0.006), Dukes stage (P = 0.0001), presence of metastases (P = 0.003), and vascular invasion (P = 0.03) had a significant prognostic impact. CONCLUSIONS: The simultaneous up-regulation of cysteine and serine proteases in CRC confirms their role in colorectal tumor biology and particularly in the process of invasion and metastasis. Together with Dukes stage, determinations of CATL, UPA, and PAI-1 have a major prognostic impact in patients with CRC.

Adult↗
PubMed1999

[The role of cathepsins and the plasminogen activator/inhibitor system in colorectal cancer].

Cysteine proteases [Cathepsin B and L (CATB, CATL)] and the serine protease urokinase type plasminogen activator (UPA) with its inhibitor type-1 (PAI-1) are thought to play an important part in colorectal cancer invasion and metastasis. To our knowledge, however, cathepsins and plasminogen activator/inhibitor system have not been evaluated in the same study. The authors using the ELISA method, determined the protease antigen concentrations in colorectal cancer tissue and in normal tissue distant from tumour, in 35 patients with colorectal cancer. They also evaluated the relationship that these proteases may have with the major histomorphological parameters and tumour staging. Significantly higher antigen levels were found: 1. in cancerous tissue vs. tumour free tissue (CATB, CATL, UPA, PAI-1); in colorectal cancer with vs. without metastasis (CATB, CATL, UPA, PAI-1); 3. in poorly vs. well differentiated tumours (CATB, UPA, PAI-1); 4. in advanced Dukes' stages (CATB, UPA, PAI-1). The simultaneous activation of cathepsins and plasminogen activator/inhibitor system in colorectal cancer confirms their role in colorectal tumor biology and particularly in the process of invasion and metastasis. Our results suggest the possible prognostic impact of these proteases in colorectal cancer.

Cathepsins↗