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Biomedical subjects

F Pagani

Publications and source records attributed to F Pagani.

At least 109 records · Page 6Linked to original sources

Clinical evaluation of an algorithm for the interpretation of hyperamylasemia.

Total amylase concentration in serum continues to be widely determined in the diagnosis of acute pancreatic disease. Accumulated experience has made clear, however, that this determination has distinct limitations. Consequently, the knowledge of the origin of hyperamylasemia may have an important influence on treatment, hospitalization, and extent of clinical investigations. We undertook a logical and systematic approach to the interpretation of hyperamylasemia through the use of an algorithm that can be applied in clinical situations without the need for the integration of radiologic procedures or clinical data. The proposed algorithm was tested for effectiveness in 97 consecutive hospitalized patients with hyperamylasemia (amylase level greater than twice the upper reference limit) for a 2-year period. The majority (52.5%) of these patients had acute pancreatitis. The algorithm assigned the correct diagnostic categories in 95.8% of cases, with a disagreement between patient diagnosis and algorithm-generated diagnosis in only four cases. These four patients (two with acute biliary disease, one with bacterial peritonitis, and one with chronic renal failure) had pancreatic lipase values greater than five times the upper reference limit, so that the algorithm classified their condition as acute pancreatitis. The clinical trial indicated that the proposed decision tree, which requires only knowledge of biochemical data that are readily available, is useful in the evaluation of elevated amylase activity and facilitates arrival at a definitive diagnosis.

Acute Disease↗

Time course of changes in pancreatic enzymes, isoenzymes and, isoforms in serum after endoscopic retrograde cholangiopancreatography.

Kinetics of the catalytic activities of total amylase (AMY; EC 3.2.1.1), pancreatic (P)-AMY isoenzyme, P2 and P3 isoforms, and pancreatic lipase (LPS; EC 3.1.1.3), and of the mass concentration of LPS in serum were studied in 10 patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) and showed a distinct pancreatic injury. The temporal characteristics of enzyme changes described were (a) the maximal rate (Ka) at which enzymes are released into blood, (b) the time lag from ERCP until maximum concentration value, (c) the peak value of each serum enzyme, and (d) the rate (Kd) at which each enzyme is cleared from serum. LPS activity and mass concentrations increased and decreased faster than AMY and isoamylases, and the time of the LPS peak tended to be earlier than that of the other enzymes, but not significantly. The average peak increase of LPS values was higher than that of total AMY, P-AMY, and P2 isoform (P less than 0.001). The P-AMY time-activity curve was a composite of curves attributable to its isoforms; the isoforms increased and peaked sequentially, with P3 returning to normal more slowly than did P2. LPS mass and activity concentrations showed excellent parallelism, with no important differences. At 50 h after ERCP, only LPS values still exceeded the upper reference limit, returning to normal 70 h after the examination.

Amylases↗

[The nonpharmacological treatment of tachyarrhythmias. The surgery of supraventricular arrhythmias not due to pre-excitation].

Surgery can provide treatment for supraventricular tachyarrhythmias without operative risk and with a definite improvement of patients' quality of life. Ectopic atrial tachycardia is a rare but invalidating arrhythmia that may lead to cardiomyopathy: intraoperative mapping is necessary for the location of the location of the ectopic focus; in our experience, surgical, cryothermal or isolation ablation of the area were effective in 9 patients out of 9, with regression of the cardiomyopathy. Atrioventricular node reentry tachycardia is a reentry tachycardia which is often associated with Wolff-Parkinson-White syndrome and is amenable to surgical treatment. Discrete cryolesions around the Koch triangle are effective in interrupting the atrial inputs to the atrioventricular node and therefore the reentry mechanism: in our experience, 7 patients were successfully treated without operative mortality: 3 patients underwent surgical ablation of Kent bundles as well. Atrial fibrillation is not based on a well-defined mechanism, and therefore does not permit an electrically-guided surgical treatment. However, in case of atrial septal defect it is possible to isolate the enlarged right atrium in order to allow sinus rhythm to activate the left atrium and ventricles.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation↗

Diagnostic value of measuring pancreatic isoamylase with a double-monoclonal antibody immunoassay in serum of hospitalized hyperamylasemic patients.

We evaluated the diagnostic utility of measuring pancreatic isoamylase (P-AMY) with a double-monoclonal antibody technique in a population of 43 consecutive hospitalized hyperamylasemic patients in comparison with serum pancreatic lipase (LPS) activity. In 27 cases (62.8%), the final diagnosis was acute pancreatitis. Predictive values were calculated for P-AMY and LPS activities, and a P-AMY percentage was calculated for selected decision levels. The maximal diagnostic efficiency was 0.930, 0.814, and 0.767 for LPS, P-AMY activity, and P-AMY percentage, respectively, indicating that serum LPS measurement was clinically superior to P-AMY for distinguishing patients with or without pancreatitis. Measurement of both P-AMY activity and percentage in serum did not significantly improve diagnostic accuracy.

Acute Disease↗

Stability of DNA methylation of X-chromosome genes during aging.

The stability of DNA methylation during aging was assessed in two groups of young (5-20 years old) and old (85-95 years old) women in DNA from blood leukocytes. Three X-linked genes were investigated. Two, G6PD and GdX, are located on Xq28, on the inactivated portion of the X chromosome: demethylation of specific regions of both genes was shown previously to be directly correlated with gene reactivation. The third, MIC2, is located on the pseudoautosomal region of the X chromosome and escapes X inactivation. The 5' region of the G6PD and GdX genes and the body of the G6PD, GDX, and MIC2 genes were analyzed with specific DNA probes. No age-related changes in methylation pattern were detected. We can conclude therefore that the methylation pattern of the three X-linked genes is stable during aging in female leukocytes and that a high rate of age-related reactivation of X-linked genes may not be a feature of all X-linked loci.

Adolescent↗

A selective role for brain histamine in prolactin release induced by opiates.

We studied the effects of histamine (HA) antagonists on the facilitatory action of morphine (M) and beta-endorphin (beta E) on prolactin (PRL) release and the effect of alpha-fluoromethylhistidine (alpha-FMH, inhibitor of HA synthesis) on beta E-induced PRL secretion. Male rats were injected intracerebroventricularly (i.c.v.) with mepyramine (MEP, H1-antagonist, 0.8 mumol/rat) or ranitidine (RAN, H2-antagonist, 0.4 mumol/rat) 10 min before M (6 mg/kg, intracarotid, i.a.) or beta E (0.25 micrograms/rat, i.c.v.). alpha-FMH (200 micrograms/rat, i.c.v.) was administered 3 h before beta E. Plasma PRL levels were measured at various times before and after drug treatment. RAN but not MEP significantly reduced PRL release induced by M whereas neither HA-antagonists nor alpha-FMH modified beta E-induced PRL release. The results obtained show that brain HA contributes through activation of H2-receptors to the PRL facilitatory action of M but not of beta E.

Animals↗

An immunochemical procedure for determination of creatine kinase 3(1) (serum-specific) isoform in human serum evaluated.

Changes in the proportions of individual isoforms of creatine kinase (CK) in serum promptly reflect both myocardial infarction and coronary reperfusion. A new commercial kit has been introduced for measuring CK-3(1) isoform in serum (ISOFOR-MM, International Immunoassay Labs.). This is an immunochemical assay containing CK-3(1) specific monoclonal antibody, bound to magnetizable particles, used to immunoextract this isoform. The CK activity of the sample is measured before and after immunoextraction and the difference in the two values gives the measure of CK-3(1). Extraction of CK-3(1) was complete at less than or equal to 1200 U/L. Analysis of between-day imprecision gave CV between 2.9-7.9%. The method was not susceptible to interference by CK-3(2) and CK-3(3) isoforms, CK-2 isoenzyme, or mitochondrial CK. Reference interval for CK-3(1) (expressed as percent of total CK-3) was 42-69%. Correlation between percent CK-3(1) by isoform electrophoresis (x) and evaluated procedure (y) was y = 0.83x + 7.6, with r = 0.957 (n = 40). The ISOFOR-MM performed well enough in this evaluation to replace electrophoresis or isoelectric focusing for measurement of CK-3(1) isoform.

Creatine Kinase↗

Human apolipoprotein A-I gene promoter polymorphism: association with hyperalphalipoproteinemia.

An apolipoprotein A-I gene promoter polymorphism, due to an adenine (A) to guanine (G) transition 78 base pairs upstream from the transcription initiation site, was studied by amplification of the corresponding region of the apoA-I gene, DNA sequencing, and allele-specific oligonucleotide hybridization. The frequency of the polymorphism was studied on female and male individuals classified into three groups according to the high density lipoprotein (HDL) cholesterol concentration. The allelic frequencies for the A polymorphism were 0.10, 0.14, 0.27 in women and 0.08, 0.17, 0.14 in men in the lowest, in the intermediate (between 10th and 90th percentile), and the highest decile of HDL cholesterol levels, respectively. Statistical analysis showed a significant difference of allelic frequencies between the highest and the lowest deciles (P less than 0.006) and between the highest and the intermediate deciles of HDL cholesterol in women (P less than 0.04) but not in men. As the sequences surrounding the polymorphism are known to be involved in transcription modulation, it is possible that the A-G transition polymorphism may have an influence on apoA-I synthesis and, in consequence, on the HDL cholesterol levels in women.

Adult↗

Evaluation of a new commercial assay kit for quantification of lactate dehydrogenase isoenzyme 1 in serum.

A new method for measuring lactate dehydrogenase (EC 1.1.1.27) isoenzyme 1 using sodium perchlorate as a chaotropic chemical selective inhibitor of all lactate dehydrogenase isoenzymes containing M-subunit was evaluated. Results with this method were precise (between-day coefficient of variation less than 9%), highly linear (coefficient of correlation = 0.9998) and correlated well with lactate dehydrogenase isoenzyme 1 as determined by the conventional immunological method (coefficient of correlation = 0.976). The reference interval for 307 healthy subjects was estimated to be 23-46 U/l (95% central range, determined non-parametrically). Being simple, convenient and amenable to automation, the method provides a substantial saving in labour and reagent costs when compared with alternative analytical approaches.

Evaluation Studies as Topic↗

A two-tube immunochemical method for determination of CK-MB isoenzyme in serum evaluated.

A new commercial kit (Impres-MB; International Immunoassay Labs.) recently was introduced for measuring the MB isoenzyme of creatine kinase (CK-MB) based on the use of monoclonal antibodies. After antibodies to CK-MM isoenzyme are added to precipitate the CK-MM, antibodies to CK-M monomer are added to precipitate the M-subunit isoenzymes of CK. Subtracting the enzymatic activity of the second supernate from the residual activity in the first yields the activity of CK-MB. Results are not affected by CK-BB, mitochondrial CK, or adenylate kinase. However, the anti-CK-MM antibodies precipitated only about 98% of serum CK-MM and may have partly precipitated CK-MB isoenzyme (average analytical recovery of CK-MB, 86.6%). Comparison between Impres-MB (y) and electrophoresis (x) yielded the following linear-regression equation: y = 0.79x + 3 (r = 0.982, n = 97). Data for CK-MB temporal kinetics, obtained from patients with myocardial infarction, correlated significantly in both methods; however, peak activity values of CK-MB were significantly different, confirming that the difference between the new method and the electrophoretic method average 20%.

Adult↗

Effects of age on binding sites for calcitonin gene-related peptide in the rat central nervous system.

The binding site distribution of calcitonin gene-related peptide (CGRP) was studied in the central nervous system of aged rats (22 months old) and compared with that of young rats (2 months). The regional distribution of [125I]Tyr-rat CGRP binding in coronal sections of young and old rat CNS was examined by an in vitro autoradiographic technique. The results, showed that in aged rats there was a marked reduction in CGRP binding, without any change in binding affinity, in the hippocampus, the nucleus rhomboideus, the nucleus arcuatus, the colliculus superior, the substantia grisea centralis and the spinal cord. In the cortical areas, the amygdala, the caudatus putamen and the accumbens binding was not modified. In the cortex cerebellaris CGRP binding was strikingly greater in the aged rats. The increase in binding might be a consequence of an adaptive process due to a decline of the peptide synthesis with age and is suggestive of a role for CGRP in the cerebellum functions.

Aging↗

Role of muscarinic receptor subtypes in the regulation of migrating myoelectric complex in the dog.

The role played by muscarinic receptor subtypes in the regulation of the migrating myoelectric complex was investigated in 7 dogs chronically implanted with bipolar electrodes along the small intestine. Pirenzepine (3-300 micrograms/kg i.v.) and atropine (1-30 micrograms/kg i.v.) were used as selective and unselective antagonist, respectively. Atropine (30 micrograms/kg) significantly delayed the onset of the next complex. On the contrary, pirenzepine displayed a biphasic action: low doses (less than 100 micrograms/kg) shortened the cycle period, whereas at 300 micrograms/kg the drug behaved like atropine. Pirenzepine affected the cycle period in the low-dose range by reducing the length of phase I. Both atropine and pirenzepine impaired the migration of the ongoing complex, and significantly reduced the migration velocity of the following one. These findings suggest that the initiation of the migrating myoelectric complex in the dog is under an inhibitory influence mediated by the M1 muscarinic receptor subtype; on the other hand, M2 receptor activation is needed for the onset of the activity front. Finally, both receptor subtypes determine the normal migration of phase III.

Animals↗

Time course of changes in serum activity of the P3 isoform of pancreatic amylase isoenzyme in patients with acute pancreatitis.

We studied the temporal sequence of serum P3 isoamylase changes in patients with acute pancreatitis, in comparison with serum pancreatic lipase (LPS) activity. Twenty-four hospitalized patients with acute pancreatitis, the onset not more than 12 h previously, were admitted to the study. Serum samples were collected daily for 6 days after onset for enzyme determinations. Measurements in the 48-h period after the onset of acute pancreatitis showed clinical sensitivities of total amylase, P3 isoform and LPS of 100%. During the following period, LPS and P3 isoform activities decreased with time with parallel changes, still showing diagnostic sensitivity significantly higher than total amylase. P3 isoform and LPS appear to be interchangeable markers of pathological release of pancreatic enzymes into the bloodstream during acute pancreatitis. However, LPS determination is more convenient because of its simplicity and shorter turnaround time.

Acute Disease↗

Evidence of a central inhibition of growth hormone secretion by calcitonin gene-related peptide.

The effects of intracerebroventricular or intracarotid injection of synthetic rat calcitonin gene-related peptide (CGRP) on growth hormone (GH) secretion induced by various stimuli in male rats were examined. CGRP (2.5 or 5 micrograms/rat intracerebroventricularly, i.c.v.) was administered 10 min before beta-endorphin (0.5 microgram/rat i.c.v.) or morphine (1 mg/kg intracarotidly, i.a.) or clonidine (0.25 mg/kg i.a.) or GH-releasing hormone (GHRH1-40; 2 micrograms/kg i.a.). When injected peripherally, CGRP (10 micrograms/rat, i.a.) was administered 5 min before morphine or GHRH. To investigate the possible involvement of somatostatin (SRIF) in the inhibition of GH secretion by CGRP, the effect of the peptide on GHRH-induced GH release was also examined in rats with hypothalamic SRIF depletion obtained by pretreatment (4 h before) with cysteamine (300 mg/kg subcutaneously). Blood samples for hormone determination were drawn from freely moving rats at various times before and after drug treatment. The intracerebroventricular administration of CGRP (5 micrograms/rat) significantly inhibited GH secretion induced by all the stimuli used. In rats with SRIF depletion CGRP did not modify the stimulation of GH by GHRH. When CGRP was administered intracarotidly, even the dose of 10 micrograms/rat did not reduce the GH release induced by GHRH or morphine. The effects of intracerebroventricular CGRP on basal or beta-endorphin-induced prolactin release were also examined. When given intracerebroventricularly, the peptide did not modify prolactin secretion. The present results indicate that CGRP has a central inhibitory role in the control of GH secretion, probably through a stimulation of SRIF release.

Animals↗

Diagnostic value of measuring pancreatic lipase and the P3 isoform of the pancreatic amylase isoenzyme in serum of hospitalized hyperamylasemic patients.

We assayed amylase (AMY) isoenzymes by cellulose acetate electrophoresis and determined pancreatic lipase (LPS) activity by a turbidimetric colipase-supplemented method in 54 hospitalized hyperamylasemic patients (32 men and 22 women; mean age 61.5, SD 16, years). In AMY isoenzyme analysis, use of a value for P3 isoform greater than 14 U/L as a positive test for acute pancreatitis gave a diagnostic efficiency of 92.6%, a predictive value of a positive test result of 90.5%, and a predictive value of a negative test of 100%. Four of 12 patients with other, nonpancreatic abdominal diseases had false-positive test results. LPS activity (cutoff limit, 700 U/L) was as effective as P3 isoform in distinguishing patients with acute pancreatitis (sensitivity, 100%) from those without acute pancreatitis (specificity, 81.3%). Thus, P3 isoform and LPS appear to be interchangeable markers of pathological release of pancreatic enzymes into the bloodstream during acute pancreatitis. This finding decreases the need for the expensive radiological procedures currently required to confirm this diagnosis. In particular, negative results virtually exclude acute pancreatitis.

Acute Disease↗