Biomedical subjects
Publications and source records attributed to M Plebani.
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We measured cyclosporine in whole blood samples from renal and heart transplant patients by high performance liquid chromatography and by two radioimmunoassays with use of specified monoclonal antibodies. In particular, we evaluated the analytical performance of a new specific radioimmunoassay with an iodinated tracer. The reproducibility of the method is satisfactory (within-run CV 7.1 to 9.5% and between-run CV 7.2 to 10.3%). The limit of detection is 10.3 micrograms/L and the analytical recovery between 99 and 114%. The results obtained with samples from both renal heart transplant patients agree well with those obtained by HPLC and by a specific RIA that uses a tritiated tracer.
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Urinary excretion of alpha-glucosidase (AGL), gamma-glutamyltransferase (GGT) and ribonuclease (RNase), and serum amylase and immunoreactive trypsin (IRT) were determined in 38 control subjects, 48 patients with pancreatic cancer, 77 with chronic pancreatitis and 47 with extrapancreatic diseases in order to ascertain the presence of a renal tubular damage and to investigate its etiology. A significantly increased frequency of pathological results for all urinary enzymes was documented in the various groups of patients as compared to controls. Significant correlations were detected among AGL, GGT and RNase. Considering the subjects as a whole, GGT and RNase excretions correlated with serum IRT and amylase; the two urinary enzymes were found to be higher when jaundice was present. In chronic pancreatic disease enzymuria was related to increased serum pancreatic enzymes; in extrapancreatic diseases it was associated to hyperbilirubinemia. The vast majority of patients with pancreatic cancer and elevated urinary enzymes presented hepatic metastases and/or jaundice. We can conclude that an anatomical and functional tubular impairment is detectable in some patients with chronic pancreatic and extrapancreatic diseases. Tubular damage seems to least in part to be related to pancreatic inflammation and necrosis in chronic pancreatic disease, while jaundice may be found to play an important role in diseases of the hepatobiliary tract. In pancreatic cancer, liver dysfunction (presence of liver metastases and/or extrahepatic cholestasis) also appears to be involved in altering tubular cells.
A different pathophysiological mechanism is widely accepted for gastric and duodenal ulcer. In particular, the exact role of gastrin in the determinism of nonhormone-dependent peptic ulcer disease has been completely clarified. The aim of the present study was to analyse fasting and postprandial serum gastrin levels in 99 duodenal ulcer patients, 17 gastric ulcer patients and 11 subjects presenting an association of gastric and duodenal ulcer. The possible correlation between postprandial gastrin concentrations and basal and maximal acid output in the 3 groups of patients has also been investigated. Fasting serum gastrin levels do not appear different among the 3 classes of patients, while postprandial gastrin concentrations are statistically higher at 15 minutes in duodenal ulcer patients and in subjects with the association of gastric and duodenal ulcer as compared to gastric ulcer patients. Mean fasting and stimulated gastrin levels are higher in gastric ulcer females than in males during the entire test and with a statistically significant difference at 30 minutes. The concentrations of the hormone are not different in males of the 3 groups of patients at basal time, while they are statistically lower at 15 and 30 minutes in gastric ulcer males compared to those with duodenal ulcer and the association of the localization. Finally, positive correlation has been observed between B.A.O. and M.A.O. and postprandial gastrin concentration in the 3 groups of patients, while there is an inverse correlation between the previous parameters as regards sex, both in gastric and duodenal ulcer.
The analytical performance of the selective multitest ABBOTT Spectrum analyser was studied according to the ECCLS guidelines and partly the CERMAB protocol in a multicentre evaluation involving laboratories from six European countries. Fifteen analytes, including the electrolytes sodium, potassium and chloride, were measured each in at least 3 laboratories, all at 37 degrees C, except the electrolytes, which are measured at room temperature. The trial lasted approximately three months and involved the collection of over 60,000 data points. It yielded the following results: 1. The precision was at least as good as the precision obtained with the comparison instruments. The majority of the coefficients of variation were between 1 and 4%. 2. The recovery for method assigned control sera values was, with few exceptions, within 10%. 3. Good agreement with respect to the method assigned values of control materials and method comparison with patient specimens to different instruments (e.g. SMAC, Hitachi 737, RA 1000) was found. 4. No drift was observed. 5. Reagent-related carry-over was not found. Specimen-related carry-over was detected in some cases, the deviation being of little or no clinical significance. 6. The manufacturer's claims regarding method linearity were as stated or exceeded. 7. The open system capability was tested and rated as very convenient. 8. The practicability of the instrument was very good.
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This study was undertaken in order to ascertain the role of CA 19-9 in pancreatic cancer diagnosis. Therefore CA 19-9 was determined in the sera of 83 control subjects, 108 patients with pancreatic cancer, 112 with chronic pancreatitis and 126 with extrapancreatic diseases. Sensitivity, specificity and accuracy in detecting pancreatic cancer were: 75%, 86% and 61% respectively. The receiver-operating characteristic curves showed that CA 19-9 is able to well discriminate pancreatic cancer from controls; satisfactorily it differentiated pancreatic malignancy from chronic pancreatitis and other benign extrapancreatic diseases. Extrapancreatic neoplasms were not accurately separated. No difference was detected in CA 19-9 levels between pancreatic cancer patients with or without hepatic metastases. We can conclude that CA 19-9 is a test for pancreatic malignancy with a satisfactory sensitivity and specificity in respect of other pancreatic and extrapancreatic benign pathologies; the presence of hepatic metastases is only one of the factors which may increase its serum levels.
Twelve children with chronic asthma were treated with a single dose of sustained-release theophylline once-a-day taken after supper at 9 PM. During the steady-state period after 15 days of treatment, serum theophylline levels were measured one and two hours after dosing and then every two hours until 9 PM the following day. The peak concentration (mean +/- SD) of serum theophylline (20.9 +/- 6.5 micrograms/mL) was observed eight hours after dosing while the through concentration (4.34 +/- 2.62 micrograms/mL) was measured 24 hours after dosing; the percent fluctuation (mean +/- SD) was 966.45 +/- 1105.55%. Another 15 children were treated with the same preparation administered at 8 AM after breakfast and at 8 PM after supper. Serum samples for theophylline concentration were obtained immediately before dosing at 8 AM and then every two hours for the following 12 hours. The mean theophylline level observed immediately before dosing at 8 AM was 10.16 +/- 3.84 micrograms/mL while the mean level at 8 PM was 9.39 +/- 4.77 micrograms/mL. The peak serum level was 13.07 +/- 5.13 micrograms/mL at 2 PM, while the trough was 9.31 +/- 3.71 micrograms/mL at 10 AM, with a percent fluctuation of 155.21 +/- 147.95%. Few side effects were seen in both groups. The results of our study clearly demonstrated that in children the percent fluctuation and peak-trough differences are far greater with once daily than with twice daily dosing and this should be considered when planning theophylline treatment in asthmatic children. The administration of a once-a-day preparation every 8-12 hours can however result in overlapping absorption patterns.
The use of recommended methods has very much improved the precision and accuracy of enzymatic determinations. The use of 'enzyme reference materials' allows us to overcome the remaining difficulties. The possibility of extending standardization by using calibration materials to convert results obtained by different methods requires an essential property: 'commutability'. The relationship between patients' specimens and reference materials are conditioned by analytical causes (relative to the used methods) and clinical causes (relative to the condition of the human samples to be examined). Among the clinical causes, the different isoenzyme content of patients sera, induced by different pathologies, was considered. The effect of this influence has been investigated with an analytical approach of the isoenzymes in the individual clinical samples. The results obtained on determination of alkaline phosphatase (ALP), creatine kinase (CK), and lactate dehydrogenase (LD), are discussed according to a model of investigation which can be utilized for the experimental protocols in the assessment of commutability.
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The relationship between some psychosocial factors and serum level of Pepsinogen Group I (PG-I) and gastrinemia have been evaluated in 163 normal subjects using correlation procedures. The psychosocial variables investigated included: age, sex, education, social class, smoking, drinking, anxiety (as measured by the State Trait Anxiety Inventory) and psychological distress (as measured by the Symptom Distress Check-List 90). The variables with the highest (positive) correlation with PG-I were smoking and age. The factors mostly linked with gastrinemia were age (positively correlated) and trait anxiety (negatively correlated). The percentage of variation explained by these variables was, however, relatively low.
To determine whether inhaled beclomethasone, both at low and at high doses, inhibits late asthmatic reactions and the associated increase in airway responsiveness induced by toluene diisocyanate (TDI), we studied 9 sensitised subjects. Low dose beclomethasone (200 micrograms bid), high dose beclomethasone aerosol (1000 micrograms bid), and placebo were administered for 7 days before TDI inhalation challenge to each subject, according to a double-blind, crossover study design. The washout period between the treatments was at least 1 week. When the subjects were treated with placebo, forced expiratory volume in 1 sec (FEV1) markedly decreased after exposure to TDI. By contrast, high dose beclomethasone prevented the late asthmatic reaction and the low dose partially inhibited the reaction. With placebo the mean (+/- SE) value of FEV1 4 h after exposure to TDI was 2.6 +/- 0.17 L, which went to 3.3 +/- 0.12 after low dose beclomethasone, and to 3.5 +/- 0.15 L after high dose of beclomethasone (significant difference in the decrease of FEV1 in the 8 h after exposure to TDI, between treatments: F = 9.87, (P less than 0.001), After treatment with placebo or with low dose beclomethasone, airway responsiveness to methacholine increased 8 h after exposure to TDI. With placebo, the PD20 decreased from 0.66 mg (Geometric Standard Error of the Mean [GSEM], 1.38) to 0.18 mg (GSEM, 1.46); with low dose inhaled beclomethasone, the PD20 decreased from 0.93 mg (GSEM, 1.42) to 0.36 mg (GSEM, 1.63).(ABSTRACT TRUNCATED AT 250 WORDS)
A study was conducted in two groups of healthy volunteers to assess whether the time of administration (10 min before the meal versus 60 min after the meal) influences the pharmacokinetics and absorption kinetics of a slow-release theophylline product (Teonova). In the first group (Group A, n = 10), the drug was given in a paired-sample design as a single dose of 600 mg before and after breakfast with an interval of at least 1 week between the two administrations. In the second group (Group B, n = 10), Teonova was given by the same study design before and after dinner. In all cases, time curves of theophylline plasma levels were determined by collecting serial blood samples 24 h after dosing and analysed pharmacokinetically through model-independent methods. In Group A, curves obtained before and after the meal were fully superimposable, and no difference was found between the pharmacokinetic parameters determined in either condition. The same result was obtained in Group B. Our results indicate that, after single dose, the two different times of administration that we tested were equivalent in pharmacokinetic terms.
CA 19-9 and tissue polypeptide antigen (TPA) were determined in the sera of 28 control subjects, 29 patients with pancreatic cancer, 26 with chronic pancreatitis and 62 with benign and malignant extra pancreatic diseases in order to compare their usefulness in diagnosing pancreatic cancer, to verify whether the combined assessment of the two indices could improve the results given by a single parameter and to speculate on the role of liver dysfunction in increasing their serum levels. The sensitivity, specificity and accuracy of CA 19-9 and TPA in diagnosing pancreatic malignancy were: 76, 85 and 61% for CA 19-9 and 79, 52 and 32% for TPA. The receiver-operating characteristic curves showed that CA 19-9 and TPA similarly discriminate pancreatic cancer from controls and chronic pancreatitis, while CA 19-9 is more useful than TPA in differentiating pancreatic malignancy from benign and malignant extra pancreatic abdominal diseases. TPA did not seem to add further information as compared to CA 19-9 alone when both markers were combined. Liver dysfunction may contribute to increasing serum levels of both markers.
To evaluate a new method for measuring pancreatic amylase in serum, in which the salivary isoenzyme is inhibited with a specific monoclonal antibody, we determined the activity of pancreatic and salivary amylase in sera from 103 healthy subjects and from 114 hospitalized patients having a wide range of total amylase activities. CVs for the proposed method ranged from 0.8% to 5.1% (within day) and from 2.3% to 6.6% (day to day). Results correlated well with those obtained by the wheat-germ inhibition method (r = 0.998) and by electrophoresis on cellulose acetate. Analytical-recovery studies confirmed the good specificity of the monoclonal antibody for salivary amylase (97%) and its low cross-reactivity (0.6%) toward pancreatic amylase. The assay procedure presents a wide range of linearity (141-1817 U/L) and can easily be adapted to an automated kinetic system. We found the proposed method suitable for routine determinations of pancreatic amylase.