Biomedical subjects

M Plebani

Publications and source records attributed to M Plebani.

At least 127 records · Page 7Linked to original sources

PubMed1998

Nutritional and prognostic significance of serum hypothyroxinemia in hospitalized patients with liver cirrhosis.

BACKGROUND/AIMS: A variety of severe illnesses can induce changes in thyroid hormone metabolism, leading to findings referred to as "sick euthyroid syndrome". In several groups of patients the reduction of serum thyroxine concentration (T4), characteristic of the low-T4 variant of sick euthyroid syndrome, has been found to be a good predictor of survival. Although the pathophysiology of hormonal alterations has not yet been defined, nutritional deficits have been suggested to play a role. The study aimed to define the prognostic and nutritional significance of serum thyroxine in liver cirrhosis. METHODS: Thyroid hormones and nutritional status were evaluated in a group of 75 consecutive hospitalized patients with cirrhosis, followed-up clinically for 12 months. RESULTS: A low-T4 variant of sick euthyroid syndrome was found in 23 of the 75 enrolled patients with cirrhosis (30.6%). Serum T4, but not serum T3, correlated with mid-arm muscle circumference (p < 0.01), an indicator of muscle protein compartment. While both serum T3 and T4 correlated directly with serum proteins and inversely with Child-Pugh score, only T4 was predictive of outcome. Patients with the low-T4 variant of sick euthyroid syndrome showed significantly lower short- and long-term survival rates compared to those with normal serum T4 concentrations (p < 0.008 at 3 months, p < 0.001 at 6 months and 1 year). A multivariate analysis using the proportional hazards Cox's regression procedure showed that serum T4, but not serum T3 or nutritional parameters, improves the prognostic capacity of Child-Pugh score (p < 0.01). CONCLUSIONS: These data indicate that the low T4-variant of sick euthyroid syndrome distinguishes a subgroup of patients with cirrhosis at risk for decreased survival. The inclusion of T4 in the Child-Pugh score, by improving its prognostic power, may optimize the selection of patients with advanced cirrhosis to receive specific therapy such as transplantation.

Adult↗

PubMed1998

Evaluation of antidiuretic hormone before and after long-term treatment with desmopressin in a group of enuretic children.

OBJECTIVE: To determine the effect of long-term desmopressin therapy in enuretic patients on the levels of antidiuretic hormone (ADH) during and after the end of therapy. PATIENTS AND METHODS: The study comprised 25 outpatients (18 boys and seven girls) aged 8-12 years at the start of therapy and 12-16 years at the end. The morning (08.00 hours) plasma ADH level was determined before treatment (T0) with desmopressin and 2 years after (T1) ending the therapy. Seven of the 25 patients evaluated had monosymptomatic (simple enuresis, SE) and 18 had other symptoms (complex enuresis, CE). RESULTS: In the patients with SE, the mean (SD) duration of therapy was 305 (183) days and they were reevaluated 2.5 (0.67) years later. Of 18 patients with CE, eight were treated only with desmopressin for 204 (117) days. In 10 with an incomplete response after 30 days with only desmopressin, oxybutynin (5 mg twice daily) was added; the duration of their therapy was 255 (152) days and they were re-evaluated 3.9 (0.6) years later. The mean (SD) ADH level in those with SE and CE was 2.14 (0.93) ng/L and 2.53 (1.16) ng/L), respectively, both significantly lower (P < 0.001) than in controls, at 5.1 (1.6) ng/L. On re-evaluation at T1, there was a significant (P < 0.001) increase in ADH levels over those at T0 in both groups, at 5.2 (0.8) and 5.3 (1.9) ng/L, respectively. CONCLUSION: These results seem to confirm the role played by ADH in the pathophysiology of enuresis.

Adolescent↗

PubMed1998

Pathogenesis of idiopathic calcium nephrolithiasis: update 1997.

Idiopathic calcium nephrolithiasis (ICN) is a frequent disease in Western countries. The physicochemical theory of lithogenesis, which explains stone formation by the precipitation, growth, and crystalline aggregation of lithogenic salts in the urine, has contributed greatly to the understanding of the pathogenesis of calcium urolithiasis. However, several aspects are still unexplained; the co-existence of familial occurrence, primary tubular dysfunctions with ICN, and anomalies in the systemic handling of oxalate and calcium led to the development of a cellular hypothesis of ICN. A number of cellular defects in the handling of ions has been reported that involves both anion and cation transport. These anomalies are probably the expression of a still unknown cellular defect in idiopathic calcium stone formers. We suggested that an anomaly in the cell membrane composition might be responsible for the complex array of cell ion flux abnormalities observed in ICN. Recently, a disorder in the n-6 polyunsaturated fatty acid series has been described; it is characterized by a lower linoleic acid content and a higher arachidonic acid concentration in both plasma and erythrocyte membrane phospholipids of renal calcium stone patients. This anomaly could cause an increased activity of ion carriers; furthermore, it may lead to increased prostaglandin synthesis and to secondary phenomena at the kidney, skeletal, and intestinal level. As a consequence, critical conditions for lithogenesis in the kidney may ensue. The data suggest a common pathogenesis for hypercalciuria and hyperoxaluria. The systemic defect in the phospholipid arachidonic acid level may be both of dietary or genetic origin; experimental data suggest that the increase in delta-6 desaturase activity, the limiting enzyme in the metabolic pathway of polyunsaturated fatty acids, might be relevant to the pathogenesis of lipid abnormalities observed in nephrolithiasis and to the pathogenesis of ICN and its related problems (at the kidney, intestinal, and bone level).

Calcium↗

PubMed1998

The TEST 1 automated system: a new method for measuring the erythrocyte sedimentation rate.

We evaluated performance of the TEST 1 (SIRE Analytical Systems, Udine, Italy), a fully automated analyzer for the measurement of the erythrocyte sedimentation rate (ESR). Intra-assay reproducibility was satisfactory for a wide range of ESR values, whereas there was a significant decrease in ESR data when the samples were stored at 4 degrees C for up to 24 hours. We compared TEST 1 with the Westergren ESR method approved by the International Council for Standardization in Haematology (ICSH) and with the Diesse Ves-Matic analyzer Linear regression analysis comparing the TEST 1 and the ICSH reference method yielded satisfactory correlations for K3 EDTA- and sodium citrate-anticoagulated samples. Bland-Altman analysis showed no evidence of a systematic bias between the TEST 1 and the reference method. A close correlation was found between the TEST 1 system and the Diesse Ves-Matic analyzer despite a significant positive systematic bias. Reference values for men and women were analyzed according to nonparametric statistics. The TEST 1 was easy to use, had a satisfactory operative practicability required minimal maintenance, and reduced contact with potential biohazards. This system enables the determination of ESR with any common standard-sized tube; the use of samples anticoagulated with K3 EDTA can widely reduce the workload in clinical laboratories.

Adult↗

PubMed1998

Helicobacter pylori cytotoxic genotype is associated with peptic ulcer and influences serology.

OBJECTIVE: We studied 146 patients with peptic ulcer disease (n = 72), antral gastritis (n = 58), or duodenitis (n = 16) to ascertain whether the cytotoxic genotype of Helicobacter pylori (Hp) is associated with peptic ulcer disease and/or antral gastritis and whether it influences the circulating levels of total anti-Hp antibodies, anti-cagA antibodies, and pepsinogens. METHODS: A gastric juice sample was obtained from each patient. After DNA extraction, polymerase chain reaction was used to amplify the genes urease A (ureA), cagA, and vacA of Hp. RESULTS: A significant association was found between peptic ulcer disease and the cytotoxic genotypes, characterized by the presence of s1 and m1 alleles of vacA and by cagA. Patients with a cagA-positive genotype showed a significant increase in anti-cagA antibodies and also had significantly increased circulating levels of pepsinogen C. CONCLUSIONS: Cytotoxic Hp strains are mainly involved in determining peptic ulcer disease, but not antral gastritis. The higher levels of circulating pepsinogen C found in patients infected with cytotoxic genotypes may reflect the higher degree of inflammation sustained by these strains.

Adult↗

PubMed1998

Analysis of Helicobacter pylori vacA and cagA genotypes and serum antibody profile in benign and malignant gastroduodenal diseases.

BACKGROUND: Helicobacter pylori species comprise different strains, cytotoxic and non-cytotoxic, which can be identified on the basis of their genomic pattern. AIMS: (1) To evaluate the polymorphism of the vacA gene and to ascertain whether the cagA gene is present in patients with gastric adenocarcinoma. (2) To study the anti-H pylori antibody profile using western blotting. PATIENTS: Twenty one patients with gastric adenocarcinoma and 71 with H pylori associated benign disease (nine gastric ulcer, 29 duodenal ulcer, 25 antral gastritis, and eight duodenitis). METHODS: The polymerase chain reaction was used to verify the presence or absence of cagA and to study the polymorphism of vacA in gastric mucosal samples obtained during endoscopy for patients with benign diseases and at surgery for patients with gastric adenocarcinoma. Fasting sera were used to assess anti-H pylori antibodies against different H pylori antigens by western blotting. RESULTS: CagA gene and the allele s1 of vacA were significantly less frequent in patients with antral gastritis (60% and 60%) compared with patients with gastric adenocarcinoma (94% and 100%) and with other non-malignant gastroduodenal diseases (93% and 87%) (chi 2 = 16.01, p < 0.001; and chi 2 = 13.97, p < 0.01). In patients with gastric adenocarcinoma, antibodies against a 74 kDa H pylori antigen were less frequently found than in patients with benign diseases. CONCLUSIONS: H pylori infection caused by cagA positive/vacA s1 strains is a frequent finding in patients with gastric adenocarcinoma. Prospective studies are needed to confirm whether the low incidence of positive serological response to the 74 kDa H pylori antigen in patients with gastric adenocarcinoma is important.

Adenocarcinoma↗

PubMed1998

p16/CDKN2 alterations and pRb expression in oesophageal squamous carcinoma.

BACKGROUND: Upregulation of the cell cycle associated genes, p16/CDKN2 and the retinoblastoma susceptibility gene (Rb), is commonly seen during the proliferation of normal cells. An inverse relation between the expression of p16/CDKN2 and Rb has been noted in many tumours, but has not yet been determined in oesophageal squamous carcinoma. AIMS: To investigate p16/CDKN2 genetic alterations and both the p16/CDKN2 and the Rb protein (pRb) immunophenotypes in oesophageal squamous carcinoma. METHODS: Twenty primary oesophageal squamous carcinomas were examined for mutations in p16/CDKN2 by the polymerase chain reaction, single stranded conformational polymorphism, and DNA sequencing. Synthesis of p16/CDKN2 and pRb proteins was determined by immunohistochemistry in 19 specimens of formalin fixed, paraffin wax embedded tissues. RESULTS: Mutations of p16/CDKN2 were not detected in exons 1 and 2. In only one case, G to C and C to T base changes were detected in a non-coding region of exon 3. Expression of p16/CDKN2 and Rb was observed in both normal and neoplastic areas of tissue sections, indicating neither consistent homozygous deletion nor consistent hypermethylation of the genes in tumours. Fourteen tumours showed an inverse expression of p16/CDKN2 and Rb. An increased percentage of cells that immunostained positively for p16/CDKN2 but not for pRb was observed in eight tumours, five of which had no detectable pRb, suggesting defective Rb expression in these oesophageal squamous carcinomas. CONCLUSIONS: These results indicate that p16/CDKN2 mutations occur infrequently in oesophageal squamous carcinoma. The alteration of the Rb gene is suggested as an important step in the development of these tumours.

Aged↗

PubMed1998

Cardiac troponin T in newborn infants with transient myocardial ischemia.

Cardiac troponin T (TnT) is a regulatory contractile protein whose detection in the circulation has been shown to be a specific and sensitive marker for ischemic myocardial cell injury both in adult and pediatric populations. We measured serum cardiac TnT in 15 consecutive full-term neonates presenting with bradycardia and electrocardiographic features of transient myocardial ischemia. Their median TnT concentrations (0.5 microg/l, range 0.01-0.37) were statistically comparable to our laboratory reference values for healthy term newborns (median 0.17 microg/l, range 0.01-0.42) (p = NS), but significantly higher with respect to our reference limits for healthy adults (median 0.01 micog/l, range 0.01-0.1) (p < 0.05). Our data demonstrate high TnT levels in neonates during the first days of life with respect to adults and similar TnT concentrations in term infants with and without TMI.

Bradycardia↗

PubMed1998

Renal tolerability of teicoplanin in a case of neonatal overdose.

The literature does not contain reports regarding teicoplanin overdose in newborns. In a neonate with a history of recent postasphyctic acute renal failure which recovered within 7 days of life, antibiotic therapy with teicoplanin was started for sepsis due to Staphylococcus hominis. However, for 5 days the dosage was excessive (20 mg/kg twice daily instead of an initial dose of 16 mg/kg and then doses of 8 mg/kg once daily). Once this error had been noted, therapy was immediately suspended. Clinically the newborn had improved and blood culture at the end of the therapy was negative. Biohumoral tests revealed constantly normal levels of serum creatinine, serum cystatin C and blood nitrogen. Urinary parameters of tubulotoxicity were also within normal values. Urinary epidermal growth factor was increased. Teicoplanin was well tolerated at the renal level in the newborn even in this case of excessive dosage.

Acute Kidney Injury↗

PubMed1998

Quantitative automated particle-enhanced immunonephelometric assay for the routinary measurement of human cystatin C.

Human cystatin C is a low molecular mass protein of 13359 Dalton recently proposed as a new very sensitive marker of changes in glomerular filtration rate. Serum cystatin C concentration correlates negatively with glomerular filtration rate as well as or better than creatinine. We evaluated a recently introduced automated nephelometric immunoassay for cystatin C in serum or EDTA-plasma samples on the Behring Nephelometer System. The assay consists of incubating the 100-fold diluted sample for 6 minutes with latex particles covalently coated with anti-human cystatin C antibodies, and then quantifying the change of light-scatter produced. Method reproducibility is satisfactory, the intra- and inter-assay coefficients of variation ranging from 1.58% to 3.77% and from 5.6% to 11.47% respectively. Rheumatoid factor (< or = 1116 IU/ml), bilirubin (< or = 418 micrommol/l), triglycerides (10.47 mmol/), and haemoglobin (12 g/l) do not significantly interfere in the assay. No significant difference was found in cystatin C concentration between serum and EDTA-plasma samples. Cystatin C is stable in serum samples stored under different conditions up to one month. This method correlates well (mean difference=-0.536+/-0.307 mg/l) with another commercially available particle-enhanced turbidimetric immunoassay. Cystatin C offers better clinical sensitivity than creatinine for discriminating patients with normal renal function and those with mild-to-moderate reduction in renal function. This method is suitable for routine cystatin C measurement, including emergencies.

Adult↗

PubMed1998

Is serum cystatin C a sensitive marker of glomerular filtration rate (GFR)? A preliminary study on renal transplant patients.

Human cystatin C is a basic low molecular mass protein (13,359 Dalton) freely filtered through the glomerulus and almost completely re-absorbed and catabolized by proximal tubular cells. We measured serum cystatin C in 38 kidney transplant patients (23 males, 15 females) aged between 6 and 32 years. To assess renal function, serum and urinary creatinine were also determined in all patients, and creatinine clearance was finally calculated. Cystatin C was determined by a particle-enhanced turbidimetric assay, and creatinine was measured by gas chromatography-mass spectrometry. To compare the diagnostic efficiency of cystatin C with that of creatinine, inulin clearance was performed on 12 renal transplant patients, and receiver operating characteristic (ROC) analysis was applied. The results of this study demonstrate that serum cystatin C significantly increases in renal transplant patients with reduced creatinine clearance (< 70 mL/min per 1.73 m2) and that the diagnostic accuracy of serum cystatin C is better than of serum creatinine. Cystatin C may be utilized as a very marker of reduced GFR.

Adolescent↗

PubMed1998

[Premature membrane rupture. Comparison of diagnostic tests].

BACKGROUND: Objective of this study was to evaluate the accuracy of the vaginal pH-test, the Fern-test, the research of foetal cells and of foetal fibronectin in vaginal discharge, which are used to diagnose premature rupture of membranes. METHODS: To this aim 40 pregnant patients between 24th and 37th weeks gestation have been examined, considered at risk for sub-clinic loss of aminiotic fluid: 23 were affected by preterm labour and 17 by suspected rupture of membranes. RESULTS: Subsequently amniotic sac was confirmed to be ripped in 10 cases (25%): 2 (8.7%) in the 23 patients with preterm labour, and 8 (47%) in the 17 patients with suspected PROM. Sensibility, specificity and accuracy were respectively: 70, 97 and 90% for pH-test; 70, 100 and 93% for Fern-test; 50, 93 and 82% for foetal cells; 100, 90 and 93% for fibronectin test. CONCLUSIONS: In personal experience fibronectin test appeared to be the most sensible and accurate marker. Fern-test was the most specific, while the research of foetal cells appeared to be the least reliable.

Adult↗

PubMed1998

Transforming growth factor beta, fibrogenesis and hyperglycemia in patients with chronic pancreatitis.

UNLABELLED: It has been suggested that transforming growth factor beta (TGFb) mediates liver fibrosis, which can be monitored by the serum determination of the N-terminal peptide of type III procollagen (PIIIP) and laminin. Fibrosis is also an important phenomenon in patients with chronic pancreatitis (CP). In 23 patients with CP, 38 with liver cirrhosis (LC) and 20 healthy controls we compared the serum patterns of PIIIP, laminin and TGFb and assessed whether in CP these markers are correlated with exocrine and endocrine function. In patients with LC, PIIIP and laminin levels were significantly higher, whereas TGFb levels were significantly lower than those of controls. In CP patients, no significant variations were found for PIIIP and laminin, although levels were high in 7/23 and in 5/23 patients, respectively. TGFb levels in CP patients were higher than those in LC patients, levels being raised in 6/23 patients. In LC patients an inverse correlation was found between PIIIP and TGFb, whereas in CP patients, a direct correlation was found between TGFb and PIIIP. Moreover, in CP patients, there was also a positive correlation between TGFb and fasting serum glucose levels, while laminin was correlated with PABA test results. IN CONCLUSION: serum biochemical markers of liver fibrosis can be considered of limited value in assessing pancreatic fibrosis; in liver cirrhosis there may be a negative feed-back regulation between TGFb production and the fibrogenetic process; and in chronic pancreatitis TGFb appears to favor fibrosis on the one hand and the development of hyperglycemia on the other.

Adult↗

PubMed1998

Complete analytical and diagnostic performances of the Abbott Cell Dyn 3500.

METHODS: The study reports the analytical and diagnostic performances of Cell Dyn 3500 (Abbott), an automated haematology analyser that provides the electrical impedance and the optical detection of total leukocyte and a five population leukocyte differential count. The evaluation of complete blood count and differential leukocyte count parameters was performed following the guidelines of the International Council for Standardization in Haematology and those of the National Committee for Clinical Laboratory Standards document H20-A. RESULTS: The CD 3500 demonstrated a good linearity, minimal carry-over, as well as acceptable levels of within and between-batch imprecision and stability. An excellent correlation between CD 3500 and the routine systems used in our laboratory (Technicon H*2 and Coulter STKS) was found for the major haematological indices, though agreement was not as good for MCHC. There was a good correlation between CD 3500 and manual reference differential method for neutrophils, lymphocytes, eosinophils and basophils, with the exception of monocytes. CONCLUSIONS: Regarding clinical sensitivity, the CD 3500 showed a high specificity to detect morphological abnormalities, but low sensitivity especially for the identification of immature granulocytes and nucleated red blood cells; if we overall evaluate any qualitative flags, we found an appreciable increase in sensitivity.

Autoanalysis↗

PubMed1998

Measurement of specific immunoglobulin E: intermethod comparison and standardization.

Recently introduced "second-generation" techniques for specific IgE measurement have produced some analytical improvement, offering better clinical sensitivity than previous techniques. The aims of our study were to compare the analytical and clinical performances of four second-generation techniques for allergen-specific IgE measurement in serum and to ascertain whether the new system for reporting quantitative results contributes to greater clinical agreement between findings using the techniques considered. Allergen-specific IgE was measured using the CAP System, CARLA, ENEA, and AlaSTAT, and the findings were compared. A significant disagreement was found between CAP and ENEA for all allergens and between CAP and CARLA for D1 and G5. However, the clinical discrepancies were reduced by selecting method-specific thresholds using ROC analysis. Second-generation techniques enable us to obtain better standardization of results; however, the identification of a specific threshold appears to be a prerequisite for the appropriate clinical interpretation of the test findings.

Adolescent↗

PubMed1998

Percent free prostate-specific antigen in assessing the probability of prostate cancer under optimal analytical conditions.

Although general consensus exists that percent free prostate-specific antigen (PSA) is superior to total immunoreactive PSA for prostate cancer (CaP) detection, its diagnostic performance is not yet well established. Analytical problems may account for difficulties in evaluating percent free PSA because the free PSA concentration is substantially lower than that of total PSA. The aim of the present study was to establish the diagnostic performances of the IMMULITE percent free PSA assay from Diagnostics Products Corp. under experimental conditions optimized to minimize analytical variability. Eighty-five patients with untreated primary CaP and 261 with untreated benign prostate hypertrophy (BPH) were prospectively enrolled. The Diagnostics Products IMMULITE total (Third Generation) and free PSA were measured by the same technician, using the same instrument and the same reagent batch. We calculated the post-test probability to express how the likelihood of the diagnosis of CaP changed after the percent free PSA was determined. Areas under the ROC curves of percent free PSA were better than those of total PSA in every evaluated range of total PSA. The percent free PSA could have reduced the rate of unnecessary biopsies by 47% in patients with total PSA >/=4 microg/L with only 3.8% false-negative results. The post-test probability of percent free PSA was, however, <50% in men 50-70 years of age, using cutoff points providing sensitivity from 99% to 80%. 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. In men with low total PSA, the diagnostic performance of the percent free PSA assay may be optimized by controlling methodological variability. The percent free PSA assay is effective in reducing the rate of unnecessary biopsies in men with total PSA >4 microg/L. However, the post-test probability provided by percent free PSA is relatively low in asymptomatic patients 50-70 years of age.

Aged↗

PubMed1998

[IgE levels in cord blood in an area of the Veneto region].

BACKGROUND: Cord blood IgE levels have been studied as a possible marker of allergy in infants but few studies are available in our Region. The aim of this paper was to test IgE levels in cord blood of 60 consecutive newborns in a restricted area of Veneto, to correlate cord blood IgE levels with family history of allergy and to verify the risk of contamination from mother's blood. METHODS: Cord blood was obtained from 60 consecutive newborns. Immunoglobulin levels (IgG, IgA, IgM, and IgE) were measured in cord blood of newborns and in serum of all mothers. Family history for allergy was previously investigated from the mothers. RESULTS: IgE were detectable in cord blood of 5 newborns but only 2 of them had positive family history for allergy which was pointed out in 11/60. In one of these cases the contamination of sample from mother's blood was postulated. IgG levels in newborn cord blood were higher than in mothers' blood and it was not related with IgE levels or other investigated factors. CONCLUSIONS: Only 6.6% of newborns in a restricted area of Veneto region have detectable IgE in cord blood whereas 18.3% of them have positive family history for allergy. Measurable levels of IgE in cord blood are not related with positive family history of allergy and are rarely influenced by mothers' blood contamination.

Adult↗

PubMed1998

Diagnostic strategies in myocardial infarction using myoglobin measurement.

Determination of myoglobin, a low molecular weight haeme protein (17.8 kDa), present in both cardiac and skeletal muscle, is an old test with new perspectives. Advantages and disadvantages of myoglobin determination are well known; recent availability of rapid and accurate methods for the assay of this protein has greatly enhanced interest in the clinical utilization of the test. However, since myoglobin is present in both skeletal and cardiac muscle, any damage to these muscle types results in its release in blood and, consequently, high levels of the protein are observed in conditions unrelated to acute myocardial infarction (AMI). New strategies for myoglobin measurement may resolve this limitation. These strategies include both the combined measurement of myoglobin and a skeletal specific marker (carbonic anhydrase III) or a cardiac specific marker (troponin I or T), as well as myoglobin evaluation on serial samples. In particular. the diagnostic algorithm based on combined measurement of myoglobin and troponins significantly improves diagnostic efficiency in laboratory assessment of suspected AMI patients. However, further efforts are necessary to improve the standardization of present methods for myoglobin measurement: the significant disagreement demonstrated between some commercially available assays should be carefully considered in clinical practice.

Biomarkers↗