Biomedical subjects

M Plebani

Publications and source records attributed to M Plebani.

At least 37 records · Page 2Linked to original sources

PubMed2003

Helicobacter pylori babA2, cagA, and s1 vacA genes work synergistically in causing intestinal metaplasia.

AIMS: To determine any associations between the Helicobacter pylori genes babA2, oipA, cagA and the s and m alleles of vacA. In addition, to verify whether these genes work synergistically or independently in causing gastritis, peptic ulcer, and intestinal metaplasia. METHODS: One hundred and sixty seven H pylori positive patients were studied (52 antral gastritis, 41 diffuse gastritis, 41 peptic ulcer, and 33 duodenitis). Helicobacter pylori virulence genes were amplified by means of the polymerase chain reaction. RESULTS: Significant associations were found between babA2 and the other H pylori genes studied. When considered singly, all the genes were associated with disease diagnosis, inflammation, and intestinal metaplasia. Four H pylori groups were defined. Group A: cagA-, s2m2, babA2-; group B: cagA+, s1m1, babA2+; group C: cagA+, s1m2, babA2+; group D: cagA+, s1m2, babA2-. Group A infecting strains were associated with less severe endoscopic and inflammatory conditions, whereas group B strains were associated with the worst endoscopic and inflammatory findings. Intestinal metaplasia was a rare finding in group A infected patients (< 10%), whereas it was frequent in those infected with group B strains (48%). CONCLUSIONS: The H pylori genes cagA, oipA "on", s1 and m1 vacA, and babA2 are associated with each other, possibly as a result of shared selective pressure. When coexpressed by the same H pylori strain, cagA, s1 and m1 vacA, and babA2 work synergistically in worsening inflammation. Infections caused by strains coexpressing cagA, s1m1 vacA, and babA2 are those at higher risk for intestinal metaplasia.

Adhesins, Bacterial↗

PubMed2002

Helicobacter pylori virulence genes and host IL-1RN and IL-1beta genes interplay in favouring the development of peptic ulcer and intestinal metaplasia.

Helicobacter pylori infection outcome might depend on genotypic polymorphisms of both the bacterium and the host. We ascertained: (1) the functionality of H. pylori oipA gene; (2) the polymorphism of the hostinterleukin (IL-1beta) gene (-31 C/T) and of the IL-1RN gene (intron 2 VNTR); (3) the association between the above genes and the histological and pathological outcome of H. pylori infection. One hundred and sixty-five H. pylori positive and 137 H. pylori negative subjects (23 gastric adenocarcinoma, 58 peptic ulcer, 221 gastritis) were studied. oipA was sequenced, IL-1beta was RFLP analysed. Antral and body mucosal biopsies were histologically evaluated. Functional oipA genes were correlated with cagA gene; both genes were significantly associated with gastritis activity, peptic ulcer and gastric adenocarcinoma. In these patients heterozygousIL-1RN 1/2 and IL-1beta C/T genotypes were more frequent than in gastritis patients. Intestinal metaplasia was associated with cagA, functional oipA and IL-1RN 2 allele. In conclusion, peptic ulcer and the preneoplastic intestinal metaplasia are associated with H. pylori virulence genes and with IL-1RN 2 host allele. An interplay between bacterial virulence factors and cytokines genotypes, is probably the main route causing H. pylori infection to lead to benign mild disease, benign severe disease or preneoplastic lesions.

Adenocarcinoma↗

PubMed2002

Biochemical markers for the prediction of spontaneous pre-term birth.

OBJECTIVES: The aim of this study was to identify predictive biochemical markers for preterm labor. METHODS: In this prospective study we included 225 asymptomatic Caucasian women consecutively enrolled at 24 weeks of gestation. The following data were collected only once at 24 weeks of gestation: vaginal pH, vaginal fFN, cervical and serum concentration of IL-6, IL-8 and TNFalpha, maternal blood serum, ferritin. Student's t-test, the chi(2)-test and multiple linear regression were used as statistical methods. RESULTS: There were no differences between the age of patients, parity and gestational age at sampling between women who delivered at term and those who delivered pre-term (<37 weeks' gestation). There was a significant increase of cervical IL-6 (pre-term 608+/-1595 pg/l vs. at term 58.9+/-112 pg/l) and serum ferritin (pre-term microg/l 74.4+/-1.1 vs. at term 26.3+/-56.5 microg/l) in pregnant women who delivered pre-term (P<0.05). No differences in cervical IL-8 and cervical TNFalpha between pre-term and term deliveries were found. Multiple linear regression confirmed that the vaginal pH value and cervical fFN test were the best predictive biochemical markers of pre-term birth (standardized coefficient Beta=0.33 and 0.22, respectively). CONCLUSIONS: In order to evaluate pregnancies for pre-term labor, the presence of pH>4.5 and a positive fFN test seems to be predictive of subsequent pre-term delivery.

Adult↗

PubMed2002

Growth hormone and insulin-like growth factor I in a Sydney Olympic gold medallist.

An Italian athlete who won a gold medal at the Sydney Olympic Games was studied. She was accused of doping after the finding of high levels of plasma growth hormone (GH) before the Games. She was studied firstly under stressed and then under unstressed conditions. In the first study, GH was measured every 20 minutes for one hour; it was above the normal range in all blood samples, whereas insulin-like growth factor I (IGF-I) was normal. In the second study, GH progressively returned to accepted normal levels; IGF-I was again normal. It was concluded that the normal range for GH in athletes must be reconsidered for doping purposes, because athletes are subject to stress and thus to wide variations in GH levels.

Adult↗

PubMed2002

ALEX (artificial liver for extracorporeal xenoassistance): a new bioreactor containing a porcine autologous biomatrix as hepatocyte support. Preliminary results in an ex vivo experimental model.

Long-term maintenance of viability and expression of differentiated hepatocyte function is crucial for bioartificial liver support. We developed a new bioreactor design (ALEX), associated with a new extracellular autologous hepatocyte biomatrix (Porcine Autologous Biomatrix - PBM) support. To test this new bioreactor, we compared it to a standard BAL (BioArtificial Liver) cartridge in a ex vivo model using human plasma added to bilirubin, ammonium and lidocaine. A pathology study was performed on both bioreactors. The results suggest that ALEX allows a maximal contact between the perfusing plasma and the liver cells and a proper hepatocyte support by a cell-to-matrix attachment. ALEX is a suitable cell support bioreactor, guaranteeing long-term maintenance of the metabolic activity of hepatocytes when compared to a standard BAL cartridge.

Ammonia↗

PubMed2002

Netilmicin effect on urinary retinol binding protein (RBP) and N-acetyl-beta-D-glucosaminidase (NAG) in preterm newborns with and without anoxia.

The study aim was to evaluate urinary excretion of Retinol Binding Protein (RBP), compared with urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), in preterm infants with anoxia and netilmicin treatment. Urinary RBP and NAG were evaluated in 83 preterm newborns divided in 4 groups: 37 healthy preterm newborns (controls); 14 with neonatal anoxia; 16 treated with ampicillin + netilmicin; 16 with neonatal anoxia and treated with ampicillin + netilmicin. RBP was determined by an automated nephelometric technique and NAG by a colorimetric method on 5-h urine samples in the first week of life. Results showed that urinary excretion of RBP (average from first week values) was 1.06+/-0.67 g/mol creatinine (mean +/- SD) in controls, 1.99+/-1.41 in antibiotic-treated newborns, 3.99+/-4.57 in anoxic newborns and 3.75+/-3.48 in anoxic newborns under antibiotic treatment. When gestational age was not considered, a marked effect of anoxia (P<0.001) and a borderline effect of netilmicin (P<0.059) on RBP excretion were detected by ANOVA. However when gestational age was also considered by analysis of covariance, it appeared as the strongest predictor of RBP excretion (P<0.001), while the effect of netilmicin was no longer significant (P=0.181). The effect of anoxia persisted, although less remarkable (P=0.010). Conversely anoxia did not affect urinary NAG excretion, which was rather correlated with gestational age and netilmicin administration. The authors conclude that RBP and NAG urinary excretion may be used to discriminate between neonatal anoxia and netilmicin treatment, respectively as etiologic factors of renal tubular damage in the newborn.

Acetylglucosaminidase↗

PubMed2001

Biochemical markers of cardiac damage: from efficiency to effectiveness.

Testing for the diagnosis of acute myocardial infarction and other diseases included in the spectrum of the so-called "acute coronary syndrome" is rapidly changing from the traditional enzymatic assays to mass measurement of more specific and sensitive markers (cardiac troponins, CK-MB and myoglobin). Several questions have arisen since the introduction of these new markers into the clinical setting: the choice of strategies for optimizing the utilization of biochemical assays combining different (early and specific) markers, the rationale for sampling specimens and the identification of clinically useful turnaround times. The impressive clinical specificity and sensitivity assured by the measurement of cardiac troponins should be used for improving the effectiveness of patients' diagnosis and treatment. Troponins could be the paradigm of how a new diagnostic test and a therapeutic advance can be combined to the benefit of patients with acute coronary syndromes. In fact, in acute myocardial infarction (AMI) patients as well as in patients suffering from stable and unstable angina, the measurement of troponins alone, or combined to that of other biochemical markers, should be of practical value for the diagnosis, for the prognosis and for selecting the most effective therapeutic treatment. Limitations in cardiac markers should be classified into two groups: temporary and intrinsic limitations. Temporary limitations are: (a) current assays are not specific as to the analyte, (b) the limited standardization precludes a comparison between results obtained with different techniques. Intrinsic limitations are the elevation of troponins in the so-called "minor myocardial damage", which often cannot be confirmed by other techniques, the evidence that other heart diseases, such as congestive heart failure and myocarditis, can lead to an increase in troponin concentrations, and finally that troponin is not an early marker. A sound cooperation between cardiologists, physicians and laboratory specialists in explaining and understanding the advantages and limitations of current biochemical markers should allow us to move from efficiency to clinical effectiveness.

Biomarkers↗

PubMed2001

Point-of-care testing of cardiac markers: results from an experience in an Emergency Department.

AIM: An experimental approach to the use of point-of-care testing for cardiac markers in the Emergency Department (ED) of our Institution has been carried out using two devices (SCS, Dade Behring and Triage Cardiac Panel, Biosite Diagnostics) for the measurement of cardiac markers. RESULTS: (1) From the analytical point of view, a fundamental tool for an efficient management of patients was the agreement between results from point-of-care testing and from the instruments located in STAT lab and/or central laboratory: in about 5% of patients, a lack of comparability of data, resulted in an inappropriate admission of patients (medical vs. intensive care unit). (2) The actual total turnaround time (TAT) in the management of samples sent to STAT lab was estimated to be equal to 82.5 min (50th percentile). (3) In the same organizational setting, the use of a point-of-care device produced a turnaround time equal to 17 min (50th percentile). (4) The reduction in turnaround time resulted in a faster discharge for five patients who had normal ECG findings and cardiac marker values, the Delta time (POCT-STAT lab) ranging from -10 to -70 min. CONCLUSIONS: The point-of-care option evaluated also in relation to personnel issues for staff working in the ED, brought some interesting questions about the characteristics of POCT devices (easy to use 100%, safety for operator 91%) and the obtained results (quantitative and correlated to STAT lab, 91%), as well as the need of other options such as the implementation of rapid tube sample delivery.

Attitude of Health Personnel↗

PubMed2001

Role of inspectors in external review mechanisms: criteria for selection, training and appraisal.

There is a wide consensus that an external review mechanism, both in the form of a peer review, accreditation and certification according to the ISO 9000 series, is more than its standards. The survey process, the role of inspectors and standard interpretation contribute to the essence of the programme itself. Above all, the criteria used for the selection, training and appraisal of inspectors are of paramount importance. While the ISO norms do not require certification bodies to employ "peer reviewers" for the healthcare sector, experience in this sector is the main criterion for recruiting inspectors in accreditation and peer review programmes. However, the ISO/IEC Guide 58, for the setting up and operation of a laboratory accreditation body, specifies that inspectors should have appropriate technical knowledge of the specific calibrations, tests or types of calibration or tests for which accreditation is sought. Training, updating and assessment of inspectors are clearly defined under ISO, but are also systematic under accreditation programmes. Part-time inspectors who are professionals currently practising in a healthcare facility and are in touch with the day-to-day work reality are preferred for accreditation programmes which have self-regulation, education and quality improvement as their main concerns, while full-time and external inspectors are used in external review mechanisms with registration and certification as their main concerns. As well as harmonising the standards for accreditation, it is important to obtain consensus on the criteria to use for the selection, training and assessment of inspectors in order to ensure that different national or international programmes gain mutual recognition.

Accreditation↗

PubMed2001

IVD industry role for quality and accreditation in medical laboratories.

Manufacturers of in vitro diagnostic (IVD) medical devices and laboratory management have become integral partners in building and improving the quality of laboratory services. There is an increasing awareness that quality is inherent in the design of any reagent or analytical system. In vitro diagnostic medical devices should provide patients, users and third parties with a high level of health protection. Therefore, both manufacturers and users must work in partnership for continual improvement. For manufacturers, standards such as ISO 9000 already exist to guide applications of quality practices. In the field of laboratory medicine, the availability of a specific, universal standard (ISO/DIS 15189) for quality management in medical laboratories will represent a great opportunity for harmonising medical laboratories at an international level. In addition, accreditation of medical laboratories according to the proposed ISO 15189 standard can help develop the relationships between laboratories, and the biological follow-up of travelling patients. Manufacturers are able to help laboratory management to reach a high level of quality, not only by providing high value products, but also on the basis of their own experience of ISO 9000 certification.

Accreditation↗

PubMed2001

External Quality Assessment Schemes: need for recognised requirements.

Programs for Accreditation of clinical laboratories consider participation in External Quality Assessment Schemes (EQAS) a key element in the evaluation of testing procedures and improving them. One of the main functions of EQAS is to assess whether laboratories perform tests competently. It is therefore of utmost importance for laboratories to participate in EQAS that are in line with formally recognised requirements. Specific proposals have been made on how to design and execute EQAS by International Working Groups, but there seems to be no consensus on the best strategies to use and quality specifications to set out. The Clinical Pathology Accreditation (CPA) Program for EQA Scheme Accreditation (CPA-EQA) is the only program in Europe to provide a formal recognition of the quality of EQAS activities. The present paper reports on the experience of the Centre of Biomedical Research which is following an accreditation process for their own schemes in line with the CPA-EQA program and a proposal to set requirements that Italian schemes must follow to be recognised as valid and effective.

Accreditation↗

PubMed2001

Analysis of Gq protein alpha subunit mRNA expression in human monocytes: relevance of the purification step.

BACKGROUND: Galphaq is a member of the Gq family of G proteins, which by stimulating the phospholipase Cbeta (PLCbeta)-IP(3)-Ca(++) mediated intracellular signaling systems controls some of the most fundamental cardiovascular cellular processes. The study of Galphaq is complicated by the presence of a pseudogene in human DNA, with signficant homology to the mRNA encoding the alpha subunit of Gq protein. The presence of this pseudogene will cause problems when the analysis of the Galphaq gene expression is based solely on RT-PCR. In this study, we report a simple method for avoiding unwanted amplification of the Galphaq pseudogene and the use of human monocytes as a readily available source for examining Galphaq. METHODS: RT-PCR was carried out on RNA extracted from peripheral blood monocytes of 10 normal subjects using specific primers for Galphaq. RESULTS: When several subjects' Galphaq was examined, the authentic Galphaq mRNA amplification product levels, as a ratio to unpurified pseudogene containing amplification products, declined by up to approximately 70%. CONCLUSION: Given the importance of Gq protein in cardiovascular signal transduction, it is fundamental to provide a reliable assessment of G alpha q gene expression. In addition to accurately assessing Galphaq levels, the use of circulating human monocytes as a useful source of Galphaq for investigating mechanisms involved in the regulation of vascular tone is shown.

Base Sequence↗

PubMed2001

Effects of cyclosporin A on human conjunctival fibroblasts.

OBJECTIVE: To evaluate the effects of cyclosporin A (CsA) on cytokine and/or collagen production, cell growth, and apoptosis in conjunctival fibroblast cultures. METHODS: Fibroblast cultures derived from normal subjects and patients with vernal keratoconjunctivitis and pemphigoid were exposed to different concentrations of CsA for either 24 hours or 30 days. The effects were evaluated by the colorimetric MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) test to assess cell proliferation, and by the measurement of procollagen I (PIP) and procollagen III (PIIIP) cytokines and total protein in culture medium. CsA-induced apoptosis was assessed by fluorescence-activated cell sorter analysis. RESULTS: After 24 hours of exposure to doses of CsA of more than 10 microg/mL, cell proliferation and migration were significantly reduced. Cyclosporin A reduced PIP and interleukin 1 (IL-1) production in a dose-dependent manner. Interleukin 6 and IL-8 were increased by 10 microg/mL of CsA, whereas transforming growth factor beta, PIIIP, and total protein were unaffected. Cyclosporin A exposure induced apoptosis in a time- and dose-dependent manner. Long-term exposure to CsA reduced IL-6 but did not modify PIIIP production. CONCLUSION: Exposure to CsA directly modified fibroblast behavior. CLINICAL RELEVANCE: Cyclosporin A ability to accelerate apoptosis in clinically fibrotic tissues may prove to be therapeutic and useful in hyperproliferative conjunctival disorders.

Apoptosis↗

PubMed2001

Role of anti-transglutaminase (anti-tTG), anti-gliadin, and anti-endomysium serum antibodies in diagnosing celiac disease: a comparison of four different commercial kits for anti-tTG determination.

The aims of this study were: (1) to compare the diagnostic efficacy for celiac disease (CD) diagnosis of serum determination of anti-gliadin (AG) (IgA and IgG) and anti-endomysium (AE) with that of anti-transglutaminase (AtTG); and (2) to compare the accuracy of four different assays to measure AtTG. We studied 72 children: the histological diagnosis of CD was made in 38 cases and excluded in the remaining 34 children. In fasting sera we measured AE, AG-IgA and IgG, and AtTG, the latter with four different commercial kits (Eurospital, Medipan, Inova, Arnika). Moreover AtTG was measured in a group of 58 CD children after a gluten-free diet. AE was positive in all but 1 case of CD patients (sensitivity = 97%); false positive results were found in 1/34 controls (specificity = 97%). When a specificity of 95% was fixed, the sensitivities were 97% for AE, 83% for AG-IgA, and 63% for AG-IgG; the sensitivities of anti-tTG were 90, 84, 84, and 75% when measured with Eurospital, Medipan, Inova, and Arnika kits respectively. The new AtTG seems to be accurate enough to be proposed as a noninvasive diagnostic tool for CD diagnosis; the 4 kits analyzed showed similar diagnostic efficacy.

Adolescent↗

PubMed2001

Serum protein profiles of patients with pancreatic cancer and chronic pancreatitis: searching for a diagnostic protein pattern.

In this study, 13 sera from patients with pancreatic cancer, 9 from chronic pancreatitis and 10 from healthy subjects were analyzed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The MALDI mass spectra revealed the presence of several low molecular weight peptides, among which some were detected only in the sera from both pathological conditions. On the other hand many peptides were observed only in control sera, and were absent in the sera from the two diseases. Therefore, MALDI analysis of the low molecular weight fraction (<10 000 Da) of sera from patients with pancreatic diseases enabled us to identify the presence of some disease-related signals and also some signals characteristic of normal subjects.

Aged↗

PubMed2001

Colorectal cancer metastatic phenotype stimulates production by fibroblasts of N-terminal peptide of type III collagen: clinical implications for prognosis.

In this study we assessed whether the serum levels of the N-terminal peptide of type III collagen (PIIIP), an index of type III collagen synthesis, are influenced by colorectal cancer stage, and whether "in vitro" fibroblast growth and PIIIP production could be altered by tumor tissues obtained from metastatic and nonmetastatic colorectal cancer. 208 colorectal cancer patients (115 colon and 93 rectum) were studied; 54 were stage I, 62 stage II, 37 stage III and 55 stage IV. PIIIP serum levels were significantly higher in stage IV as compared to all other patient groups. The 5-year survival of stage I, stage II, stage III and stage IV patients were 87%, 88%, 32% and 20%, respectively. In the subgroup of stage I and stage II patients considered together, PIIIP (> 0.5 U/ml), but not CEA (> 5 microg/l) serum levels, were predictive for survival. Fibroblast growth was significantly inhibited, while PIIIP production was significantly enhanced, when these cells were conditioned with colorectal cancer homogenates obtained from patients with distant metastases, than from those without distant metastases. In conclusion, colorectal tumors, when metastatic, stimulate fibroblasts' PIIIP synthesis and the serum levels of this peptide might predict patients' outcome after radical surgery.

Carcinoembryonic Antigen↗

PubMed2001

IgE binding to soluble and insoluble wheat flour proteins in atopic and non-atopic patients suffering from gastrointestinal symptoms after wheat ingestion.

BACKGROUND: The involvement of IgE-mediated hypersensitivity reactions in the genesis of gastrointestinal symptoms after ingestion of foods containing wheat has been rarely reported. OBJECTIVE: To detect IgE specifically binding to wheat proteins in the sera of atopic and non-atopic patients suffering from gastrointestinal symptoms after ingestion of wheat and to evaluate the reliability of skin prick test and CAP in the diagnosis of food allergy to wheat. METHODS: The sera of patients (10 atopic and 10 non-atopic) previously diagnosed as suffering from irritable bowel syndrome and complaining of symptoms after wheat ingestion were analysed by immunoblotting for IgE binding to water/salt-soluble and insoluble wheat flour proteins. RESULTS: All the atopic patients and only one of the non-atopic patients were positive to wheat CAP. For the patients tested, skin prick test was positive for all the atopic patients and for only one of the non-atopic patients. However, immunoblotting experiments showed the presence of specific IgE to wheat proteins in all the patients. Ten out of 11 of the wheat CAP-positive patients had IgE binding to a soluble 16-kDa band, but the same band was recognized, in a slighter way, by only two out of nine of the wheat CAP-negative patients. Moreover, although almost all of the patients were negative in CAP testing with gluten, 19 out of 20 recognized protein bands belonging to the prolamin fraction. CONCLUSIONS: For the atopic patients the positivity to skin prick test and CAP to wheat was in accordance with the immunoblotting results and a food allergy to wheat could be diagnosed. In these patients a major allergen was a 16-kDa band corresponding to members of the cereal alpha-amylase/trypsin inhibitors protein family, the major allergens involved in baker's asthma. In the non-atopic patients the positive immunoblotting results contrasted with the responses of the allergologic tests, indicating that the allergenic wheat protein preparations currently used are of limited value in detecting specific IgE to wheat and that the fraction of irritable bowel syndrome (IBS) patients with food allergy may be larger than believed.

Adult↗

PubMed2001

Serum-mediated relaxant response to toluene diisocyanate (TDI) in isolated guinea-pig bronchi.

The present study was designed to evaluate whether pre-incubation with serum, obtained from both control and toluene diisocyanate (TDI)-immunized guinea-pigs, modified the contractile response to TDI in isolated guinea-pig bronchial rings. Guinea-pigs were anaesthetized and the main bronchi dissected in two rings. Bronchial rings were incubated with normal or immune serum (100 microl ml(-1) for 2 h) and dose-response curves to TDI (0.03-1000 microM) were studied isometrically. Before serum incubation, in eight bronchial rings, epithelium was removed by rubbing the luminal surface gently with a gauze. In control rings, TDI produced a concentration-dependent contraction, whereas in rings pre-incubated with either normal or TDI-immune serum, it produced a concentration-dependent relaxation. Relaxation was 101.4 (SEM 17.4)% and 94.9 (SEM 21)% of the relaxation induced by isoproterenol (1 mM) respectively with normal and TDI-immune serum. Similarly to the pre-incubation with serum, pre-incubation with albumin produced a concentration-dependent relaxation to TDI. Serum-induced relaxant response to TDI was not affected by capsaicin desensitization, it was only partially inhibited by an NK1-tachykinin antagonist, whereas it was blocked by indomethacin. In bronchial rings without epithelium, pre-incubated with serum, TDI caused contraction at highest doses, while it still induced relaxation at the lowest doses. This study shows that one or more components of the serum modify the contractile response to TDI in isolated guinea-pig bronchi. In bronchial rings without epithelium serum was able to inhibit the contration induced by low doses of TDI.

Albumins↗