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Biomedical subjects

Giuseppe Lippi

Publications and source records attributed to Giuseppe Lippi.

At least 73 records · Page 4Linked to original sources
PubMed2005

Preanalytical variability in laboratory testing: influence of the blood drawing technique.

The predominant technique used to draw blood for laboratory testing is a conventional straight needle attached to an evacuated tube system. However, alternative tools might be advantageous in exceptional circumstances. The use of butterfly devices has been traditionally discouraged for reasons of costs and due to the high risk of obtaining unsuitable samples, but there is no convincing evidence to support the latter indication. The purpose of this study was to compare results of hematological and clinical chemistry testing, after drawing blood into evacuated tubes, employing either a traditional 21-gauge straight needle or a 21-gauge butterfly device with 300-mm-grade polyvinyl chloride tubing. Blood samples and complete sets of data were successfully obtained for 30 consecutive outpatients. Of the 43 hematological and clinical chemistry parameters measured, means for paired samples collected by the two alternative drawing techniques did not differ significantly, except for serum sodium, white blood cells and platelets counts. Bland-Altman plots and limits-of-agreement analysis showed mean bias of between -7.2% and 1.7% and relative coefficients of variation ranging from 0.2% to 21.2%. The 95% agreement interval in the set of differences was acceptable and was mostly within the current analytical quality specifications for desirable bias. The rate of hemolysis in plasma was not statistically different between the two collection techniques. Taken together, the results of the present investigation suggest that, when a proper technique is used and within certain limitations, the butterfly device may be a reliable alternative to the conventional straight needle to draw blood for laboratory testing.

Blood Specimen Collection↗
PubMed2005

High-workload endurance training may increase serum ischemia-modified albumin concentrations.

The measurement of cardiac troponins has emerged as the biochemical "gold standard" for the diagnosis and management of patients with acute chest pain. However, earlier markers should support investigation strategies, as several patients with acute coronary syndrome might present with non-diagnostic concentrations. Ischemia-modified albumin (IMA), measured by the albumin cobalt binding (ACB) assay, was recently proposed for early detection of myocardial ischemia. To establish the potential influence of endurance training on the diagnostic approach to patients with suspected myocardial injury, cardiac troponin T (cTnT), creatine kinase isoenzyme MB (CK-MB), myoglobin and IMA were evaluated in healthy individuals subjected to different aerobic workloads. The concentrations of both IMA and CK-MB were significantly increased in athletes subjected to high-workload endurance training, whereas the concentration of cTnT and myoglobin was not influenced by physical exercise in the medium term. Taken together, our results demonstrate that demanding aerobic physical activity might influence the generation of IMA, which might be increased in the medium term following high-workload endurance training, while the concentration of other conventional markers of myocardial injury remains non-diagnostic.

Adult↗
PubMed2005

Influence of short-term venous stasis on clinical chemistry testing.

Control and standardization of preanalytical variability is a critical factor for achieving accuracy and precision in laboratory testing. Although venous stasis from tourniquet placement during venepuncture should be minimized, as it has been claimed to account for spurious and significant variations for several analytes in plasma, there is controversy surrounding its real impact on laboratory testing. The aim of the present study was the investigation of the influence of short-term venous stasis on routine biochemical testing, by measuring the plasma concentration of 12 common analytes, including proteins, protein-bound substances, enzymes and electrolytes, in plasma specimens collected either without venous stasis or following the application of standardized external pressure of 60 mm Hg using a sphygmomanometer for 1 and 3 min. Although the overall correlation between measures was acceptable, the pattern of change was mostly dependent on the length of stasis, size and protein-binding characteristics of the analytes, achieving clinical significance for albumin, calcium and potassium after 1-min stasis, and alanine aminotransferase, albumin, calcium, chloride, total cholesterol, glucose and potassium after 3-min stasis. Statistically significant differences could be observed in seven (alanine aminotransferase, albumin, calcium, total cholesterol, creatine kinase, iron and potassium) and ten (alanine aminotransferase, albumin, calcium, chloride, total cholesterol, creatine kinase, creatinine, glucose, iron and potassium) out of the 12 analytes tested, after 1- and 3-min venous stasis, respectively. The most clinically significant changes from standard venepuncture, when compared to the current analytical quality specifications for desirable bias, occurred for potassium (1-min stasis, -2.8%; 3-min stasis, -4.8%, both p<0.001), calcium (1-min stasis, +1.6%, p<0.05; 3-min stasis, +3.6%, p<0.001) and albumin (1-min stasis, +3.5%; 3-min stasis, +8.6%, both p<0.001). As most of these effects are dependent on the stasis time during venepuncture and biochemical or physiological characteristics of the analyte, these variations could likely be anticipated, allowing the most appropriate preventive measures to be adopted.

Adult↗
PubMed2005

Clinical heterogeneity of acquired hemophilia A: a description of 4 cases.

Acquired hemophilia A is a rare but severe auto-immune bleeding disorder characterized by the presence of autoantibodies directed against clotting factor VIII. Acquired hemophilia A may be idiopathic or associated with several conditions, such as postpartum, autoimmune diseases, malignancies or drugs. The treatment modalities of bleeding episodes and eradication of the factor VIII auto-antibody depend on the titer of anti-factor VIII:C and may include desmopressin (DDAVP), prednisolone, prednisolone-cyclophosphamide, high dose intravenous gammaglobulin, FVIII-VWF concentrate and/or recombinant FVIIa (rFVIIa). In this study we report four cases of autoimmune factor VIII inhibitors (2 associated with autoimmune disorders, 2 idiopathic) demonstrating the heterogeneity of this disease from pathogenic, clinical, therapeutic and prognostic points of view.

Autoantibodies↗
PubMed2005

[New perspectives in the diagnostic approach to acute coronary syndrome].

Cardiovascular disorders and acute coronary syndrome represent the leading pathologies in western countries. Over 30 years from the first diagnostic criteria issued by the World Health Organization, the diagnostic approach to patients with non-traumatic chest pain is as yet challenging. Investigators have attempted various diagnostic strategies, such as clinical decision algorithms, cardiac biomarkers, echocardiography, and myocardial perfusion imaging to avoid missing patients with myocardial ischemia or unstable angina. Although the pivotal role of cardiac troponins has now been widely recognized in the clinical management of myocardial ischemia, several patients with acute coronary syndrome might present with nondiagnostic concentrations on admission. The appropriate utilization of economical and therapeutical resources largely depends on early risk stratification, to either rule out or diagnose acute coronary syndromes, and early markers of myocardial ischemia and reliable prognostic indicators should now support investigative strategies. The ischemia-modified albumin and the brain natriuretic peptides have been recently proposed as promising markers for the early stratification of risk and prognosis. If reliable studies will confirm their suitability for evaluating patients presenting with acute coronary syndrome, a novel diagnostic approach might issue.

Acute Disease↗
PubMed2004

Comparison of serum creatinine, uric acid, albumin and glucose in male professional endurance athletes compared with healthy controls.

Owing to considerable physical, endocrinological and metabolic adaptations, the analysis of biochemical data in elite and top-class athletes requires caution. With the aim to identify metabolic and biochemical adaptations to particular lifestyle conditions, such as regular and strenuous physical exercise, we measured the concentration of serum albumin, creatinine, uric acid and glucose in 80 male professional cyclists, 37 male members of the Italian national cross-country ski team and 60 male healthy sedentary controls at rest. At variance with earlier investigations, endurance athletes showed significantly decreased concentrations of serum creatinine (controls: 83.1+/-11.0 micromol/l; skiers: 78.0+/-8.4 micromol/l; p<0.05; cyclists: 73.8+/-10.4 micromol/l; p<0.01), uric acid (controls: 362+/-69 micromol/l; skiers: 331 +/-70 micromol/l; p<0.05; cyclists: 312+/-61 micromol/l; p<0.01) and glucose (controls: 5.35+/-0.54 mmol/l; skiers: 4.94+/-0.41 mmol/l; p<0.01; cyclists: 4.94+/-0.42 mmol/l; p<0.01). The concentration of serum albumin was also decreased in athletes, but the difference did not reach statistical significance (controls: 4.76+/-0.26 g/l; skiers: 4.71+/-0.22 g/l; p=0.384; cyclists: 4.68+/-0.22 g/l; p=0.393). Results of the present investigation demonstrate that values of laboratory testing lying outside conventional reference limits calculated on sedentary populations might express physiological adaptations to regular and demanding physical aerobic activity, emphasizing the need for the estimation of reliable reference limits in elite and professional athletes, to avoid equivocal interpretation of results within clinical and anti-doping contests.

Adaptation, Physiological↗
PubMed2004

[Hepatitis C in hemophiliacs].

Hepatitis C virus (HCV) infection is an important cause of morbidity and mortality in patients with hereditary bleeding disorders treated with non virus inactivated clotting factor concentrates during the 1970s. In this article, we briefly report the actual knowledge about HCV infection in hemophiliacs, by analyzing the prevalence of HCV infection, the genotype distribution, the natural history of the infection and the most important factors involved in the progression of chronic hepatitis into liver cirrhosis, hepatic decompensation and hepatocellular carcinoma. Finally, we describe the main advances in the treatment of HCV infection.

Hemophilia A↗
PubMed2004

[Clinical use of erythropoietin].

The introduction of recombinant human erythropoietin (RHuEPO) has dramatically changed the therapeutic approach to the anemia of chronic renal failure. Clinical studies have also demonstrated that RHuEPO is effectiveness in various non-uremic conditions, such as anemia associated with onco-hematological disorders, prematurity, HIV infection and to reduce the exposure to allogeneic blood in surgical patients. In this review, we briefly analyze the main clinical applications of RHuEPO, with particular attention to the potential complications deriving from its use.

Adult↗
PubMed2004

High prevalence of acquired von Willebrand's syndrome in patients with thyroid diseases undergoing thyroid surgery.

BACKGROUND AND OBJECTIVES: Various coagulation abnormalities occur in patients with thyroid diseases. These abnormalities range from subclinical laboratory findings to hemorrhage or thromboembolism. However, the prevalence of hemostatic abnormalities in patients with thyroid diseases is still unclear. DESIGN AND METHODS: Between January 1999 and December 2003, 1342 consecutive patients with various thyroid diseases who were candidates for thyroid surgery underwent preoperative screening of hemostatic parameters including prothrombin time, activated partial thromboplastin time and platelet-related hemostasis with the PFA-100 platelet-function analyzer. RESULTS: Thirty-nine patients (2.9%) had abnormalities of the coagulation screening tests. Of these, 35 patients had von Willebrand's disease (type 1 in 33 cases and type 2A in 2 cases), 2 patients had decreased platelet aggregability, and 2 patients had coagulation factor XI deficiency. As all patients with coagulation abnormalities responded to subcutaneous desmopressin injection (0.3 microg/Kg BW), this drug was successfully used as surgical prophylaxis. INTERPRETATION AND CONCLUSIONS: Up to 3% of patients with thyroid diseases undergoing thyroid surgery have coagulation abnormalities, in most cases resembling von Willebrand's disease. Coagulation screening tests are needed in order to identify those patients at increased risk of bleeding.

Adolescent↗
PubMed2003

Lipoprotein(a): an emerging cardiovascular risk factor.

Lipoprotein(a) is a cholesterol-enriched lipoprotein, consisting of a covalent linkage joining the unique and highly polymorphic apolipoprotein(a) to apolipoprotein B100, the main protein moiety of low-density lipoproteins. Although the concentration of lipoprotein(a) in humans is mostly genetically determined, acquired disorders might influence synthesis and catabolism of the particle. Raised concentration of lipoprotein(a) has been acknowledged as a leading inherited risk factor for both premature and advanced atherosclerosis at different vascular sites. The strong structural homologies with plasminogen and low-density lipoproteins suggest that lipoprotein(a) might represent the ideal bridge between the fields of atherosclerosis and thrombosis in the pathogenesis of vascular occlusive disorders. Unfortunately, the exact mechanisms by which lipoprotein(a) promotes, accelerates, and complicates atherosclerosis are only partially understood. In some clinical settings, such as in patients at exceptionally low risk for cardiovascular disease, the potential regenerative and antineoplastic properties of lipoprotein(a) might paradoxically counterbalance its athero-thrombogenicity, as attested by the compatibility between raised plasma lipoprotein(a) levels and longevity.

Arteriosclerosis↗