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Biomedical subjects

A Tripodi

Publications and source records attributed to A Tripodi.

At least 37 records · Page 2Linked to original sources
PubMed2002

European Concerted Action on Anticoagulation (ECAA): multicentre international sensitivity index calibration of two types of point-of-care prothrombin time monitor systems.

A multicentre modified World Health Organization (WHO)-type international sensitivity index (ISI) calibration has been performed at 10 European Concerted Action on Anticoagulation (ECAA) national laboratories using non-citrated whole-blood on two point-of-care test (POCT) prothrombin time (PT) monitor systems, CoaguChek Mini and TAS PT-NC, using single lots of test cards/strips. The relevant species (human and rabbit) WHO international reference preparations (IRPs) were tested with the manual PT technique on citrated plasma from the same blood donations. The ISI was calculated from the slope of the orthogonal regression line relating log PT (POCT) to log PT (IRP). The mean ISI of the CoaguChek Mini system was 1.75 and 1.13 with the prothrombin time non-citrated Thrombolytic Assessment System (TAS PT-NC). With the CoaguChek Mini system, seven out of 10 calibrations exceeded the current 3% WHO recommended limit for the coefficient of variation (CV) of the slope with conventional PT testing, whereas with the TAS PT-NC system, it was eight out of 10. All the POCT calibrations had a CV of the slope <5%. It is suggested that this level of precision be adopted as the limit of acceptability of calibration of these monitor systems. In these circumstances, the modified WHO-type ISI calibration appeared to be satisfactory for the POCT whole-blood monitors.

Animals↗
PubMed2002

European Concerted Action on Anticoagulation--comparison of fresh plasma and whole blood multicentre ISI calibrations of CoaguChek Mini and TAS PT-NC whole blood prothrombin time point-of-care monitors.

A procedure for using citrated fresh plasmas for International Sensitivity Index (ISI) calibration of two types of whole blood point-of-care test (POCT) prothrombin time (PT) monitor systems has been assessed in a multicentre study. The CoaguChek Mini and TAS PT-NC systems gave higher ISI with whole blood samples than with fresh plasma calibrations. However. there was good agreement between whole blood and fresh plasma monitor system International Normalised Ratio (INR) and the reference INR of target samples. Reliable INR can therefore be obtained with both whole blood and plasma samples on these two POCT systems based on their respective ISI. With the CoaguChek Mini system, the plasma calibration ISI can also be used to derive reliable INR with whole blood PT results. This was not possible with the TAS PT-NC system.

Animals↗
PubMed2002

A reassessment of the relationship between international reference preparations for human and rabbit thromboplastins.

Two established international reference preparations (IRP) for thromboplastins, i.e. RBT/90 (rabbit, plain) and rTF/95 (recombinant human, plain) have been calibrated against each other in a 7-centre exercise performed in 2000. The purpose of the study was to compare the calibration results with those of the original calibration study performed in 1995. The international sensitivity index (ISI) for rTF/95 was calculated relative to the ISI for RBT/90. The mean ISI for rTF/95 was 0.961 (between-lab SD 0.028) which was 2% greater than the historical value determined in 1995. There is no indication that the two IRP have deteriorated, but further monitoring of the calibration relationship is recommended.

Animals↗
PubMed2002

European Concerted Action on Anticoagulation (ECAA): International Normalized Ratio variability of CoaguChek and TAS point-of-care testing whole blood prothrombin time monitors.

The object was to assess the variability in displayed International Normalised Ratio (INR) between monitors of the same manufacture using whole blood samples from the same subjects. Two brands of monitor, CoaguChek Mini and the TAS PT-NC were tested. 14 instruments of each brand were tested on the same day at the same laboratory by the same operator using identical blood samples to avoid between-centre differences in samples and operator technique. Whole blood samples from two normal donors and four coumarin-treated patients were tested to assess between-instrument variability of INR. Results have been coded. There was a much wider dispersion of INR on Brand B than on Brand A. One Brand A instrument failed to give a result with one of the two whole blood samples from one patient. One Brand B monitor gave an aberrant result with one of the samples from a normal subject. On both brands of monitor, INR variability appeared to be due mainly to duplication differences rather than between-instrument variability on both normal and coumarin whole blood samples.

Analysis of Variance↗
PubMed2001

Laboratory control of oral anticoagulant treatment by the INR system in patients with the antiphospholipid syndrome and lupus anticoagulant. Results of a collaborative study involving nine commercial thromboplastins.

Because of the variable responsiveness of thromboplastins to lupus anticoagulants (LA), concerns have been raised about the validity of the prothrombin time-International Normalized Ratio (PT-INR) in monitoring oral anticoagulant treatment in patients with the antiphospholipid syndrome (APS) and LA. To date, few studies have been performed, numbers of patients investigated are relatively small and results are conflicting. We report on a multicentre study organized to investigate further this clinically relevant issue. Each of nine thrombosis centres was asked to collect plasma samples from patients with APS who were on oral anticoagulants (cases) and patients without APS who were on oral anticoagulants (controls). Nine thromboplastins (three human recombinant, one from human placenta and five from rabbit brain) were calibrated at the co-ordinating centre according to World Health Organization guidelines. Measurements of the INR and factor X amidolytic activity for all frozen plasmas were performed centrally. The numbers of patients investigated were 58 cases and 57 controls. Between-reagent variability of the INR was higher in cases [coefficient of variation (CV) = 12.4%] than in controls (CV = 6.7%), but this was because of one of the thromboplastins only (Thromborel R, human recombinant), which measured considerably higher INR values than the others in cases but not in controls. In conclusion, our data indicate that LA interference on the PT-INR measured with the majority of commercial thromboplastins is not enough to cause concern if insensitive thromboplastins, properly calibrated to assign them an instrument-specific International Sensitivity Index are used. New thromboplastins, especially those made of relipidated tissue factor, should be checked for their responsiveness to LA before they are used to monitor oral anticoagulant treatment in patients with APS.

Animals↗
PubMed2001

Multicenter study of homocysteine measurement--performance characteristics of different methods, influence of standards on interlaboratory agreement of results.

After the demonstration that moderate hyperhomocysteinemia is associated with thrombosis, many hematological labs are becoming interested in total homocysteine (tHcy) measurement. This prompted us to organize a collaborative study to investigate the performance of methods used in this setting and to assess the between-lab comparability of results. Two pairs of pooled plasma (A1-A2 and B1-B2) were prepared at the coordinating Center. tHcy levels were normal in A1-A2 and moderately high in B1-B2. Within each pair tHcy levels were similar but not identical. Aliquots were taken from each pool to prepare sets of 100 samples (coded from 1 to 100). Each set consisted of 25 replicates for each pool. Samples were frozen and shipped in dry ice to 16 labs with a common frozen aqueous standard. Labs were asked to measure (in blind) tHcy with their methods and standards. Results were sent to the coordinating Center both as raw readings and as tHcy levels. The following methods were used: High Pressure Liquid Chromatography (HPLC) in 12 labs (home-made in 10 and commercial in 2); Enzyme Immuno Assays (EIA) in 2; Fluorescence Polarization Immunoassay (FPIA) in 2 and Capillary Electrophoresis (CE) in one. Results for paired pools (A1-A2 and B1-B2) were analyzed by the Student t test to assess for the ability to discriminate between similar but not identical tHcy levels. Results for each pool were used to assess within-lab reproducibility and between-lab comparability. Within-lab reproducibility expressed as median CV ranged from 12.6 to 13.9% (home-made HPLC); from 9.2 to 11.4% (commercial HPLC); from 21.8 to 24.2% (EIA); from 2.7 to 3.3% (FPIA) and from 11.2 to 22.0% (CE). All labs, except one using CE and 2 using home-made HPLC, were able to discriminate between similar tHcy levels in the normal range (pools A1-A2). Ten labs (4 using home-made HPLC, 2 commercial HPLC, 2 FPIA, one EIA and one CE) were able to discriminate between similar moderately high tHcy levels (pools B1-B2). Between-lab comparability expressed as CV was 14.0% 13.9%, 15.6% and 14.5% for pools A1, A2, B1, and B2. These values were considerably lower (CV values < 5.2%) when a common plasma standard was used for calculation of tHcy levels, while the use of a common aqueous standard failed to achieve the necessary harmonization. In conclusion, performance characteristics of the FPIA method compare favorably with the well-established HPLC methods. It is simpler and more suitable to be used by general hematological labs. Between-lab comparability of results is still a problem. The establishment of an international plasma standard would be of help to harmonize tHcy measurement across laboratories.

Chromatography, High Pressure Liquid↗
PubMed2001

Bilateral, tubal pregnancy treated with conservative endoscopic surgery.

Bilateral tubal pregnancies are very rare and those diagnosed during surgery, and at the same gestational age, are even more rare. A 28-year-old womand who had been treated with conservative laparoscopy for another tubal pregnancy a few years before and lateral by laparotomy for corpus luteal hemorrage had a bilateral tubal pregnancy treated by conservative endoscopic surgery.

Adult↗
PubMed2001

Laboratory investigation of thrombophilia.

Until recently, laboratory diagnosis of thrombophilia was based on investigation of the plasmatic anticoagulant pathways to detect antithrombin, protein C, and protein S deficiencies and on the search for dysfibrinogenemia and anti-phospholipid antibodies/lupus anticoagulants. More recently, laboratory investigations have been expanded to include activated protein C (APC) resistance, attributable or not to the presence of the factor V Leiden mutation; hyperprothrombinemia attributable to the presence of the prothrombin gene mutation G20210A; and hyperhomocysteinemia attributable to impairment of the relevant metabolic pathway because of enzymatic and/or vitamin deficiencies. All of the above are established congenital or acquired conditions associated with an increased risk of venous and, more rarely, arterial thrombosis. Testing is recommended for patients who have a history of venous thrombosis and should be extended to their first-degree family members. Because most of the tests are not reliable during anticoagulation, it is preferable to postpone laboratory testing until after discontinuation of treatment. Whenever possible, testing should be performed by means of functional assays. DNA analysis is required for the prothrombin gene mutation G20210A. Laboratory diagnosis for anti-phospholipid antibodies/lupus anticoagulant should be performed by a combination of tests, including phospholipid-dependent clotting assays and solid-phase anti-cardiolipin antibodies. Hyperhomocysteinemia can be diagnosed by HPLC methods or by fluorescence polarization immunoassays.

Activated Protein C Resistance↗
PubMed2001

Cryopreservation of oocytes after vitrification.

Recently the majority of studies and research in the field of physiopathology of reproduction have been oriented towards cryopreservation of female eggs. This could resolve the ethical problems connected with the preservation of the embryo and with the gestation of the surplus oocytes collected after cycles of ovarian hyperstimulation. Notwithstanding that extraordinary results have been obtained in the field of cryopreservation of embryos and spermatozoa, the freezing of oocytes involves unfortunately many difficulties in relation, above all, to deep morphostructural and functional modifications which take place due to the low temperatures and to the toxic action of cryoprotective agents. The aim of this work was to test and then verify whether an efficient method of preserving the female egg cells by freezing in order to be able to subsequently use them for in vitro fertilization. The conclusions of this study, even if not highly encouraging, have allowed us to better evaluate the damage caused by low temperatures and at the same time should stimulate us and other researchers in this field to find new methods which will allow us to reach higher aspirations.

Animals↗
PubMed2000

Alpha(2)-macroglobulin levels are high in adult patients with congenital antithrombin deficiency.

Antithrombin is responsible for about 80% of the progressive inhibitory activity of thrombin in human plasma. The role of other protease inhibitors known to inhibit thrombin is not completely clarified. However, their contribution may become relevant when antithrombin is low. We elected to investigate adult patients with congenital antithrombin deficiency to assess the concentration of other naturally occurring thrombin inhibitors such as alpha(2)-macroglobulin, alpha(1)-antitrypsin, heparin cofactor II, and C(1)-inhibitor. The study included 59 patients with congenital antithrombin deficiency with and without a previous history of thrombosis, together with an equal number of control subjects matched for age and sex. Statistically significant differences (patients vs. controls) were observed only for alpha(2)-macroglobulin (i.e., 120 vs. 102%, p<0.01). Further analysis of antithrombin-deficient carriers with and without a past history of thrombosis showed that alpha(2)-macroglobulin levels were higher than the 90th percentile of control distribution more often in asymptomatic than symptomatic men (odds ratio=0.04; confidence interval=0.003-0.60), but not in women (odds ratio=2.14; confidence interval=0.35-13.1). In conclusion, results from this cross sectional study showed that alpha(2)-macroglobulin levels were high in patients with congenital antithrombin deficiency. Furthermore, the high levels were found more often in asymptomatic than symptomatic men. Whether this increase provides protection against thrombosis should be evaluated in a prospective study.

Adolescent↗
PubMed2000

Dramatic improvement of LV function after coronary sinus thromboembolectomy.

We present the case of a 79-year-old man suffering from chronic atrial fibrillation, severe left ventricular dysfunction, massive right atrial thrombosis, and pulmonary hypertension. Complete coronary sinus thrombosis was found incidentally during preoperative screening. Successful coronary sinus, right atrial, and pulmonary operative embolectomy was followed soon after by a dramatic improvement of cardiac performance; the patient's left ventricular function recovery, in particular, suggests that cardiac venous system played an important role in the genesis of myocardial impairment.

Aged↗
PubMed2000

Localized dissection and delayed rupture of the abdominal aorta after extracorporeal shock wave lithotripsy.

Extracorporeal shock wave lithotripsy (ESWL) represents the preferred treatment for most upper ureteric and renal calculi. Complication rates associated with ESWL are low, justifying the enthusiasm and acceptance of this treatment modality. As the technique has become more widely available, some deleterious effects on the kidneys and the surrounding tissues are increasingly recognized. We report on the rupture of a severely calcified abdominal aorta in a 65-year-old man who underwent 3 months of ESWL treatment earlier for renal calculi. The patient was seen with an acute recrudescence of a long-standing abdominal and left flank pain, which began immediately after the last of the three sessions of ESWL and was associated with an episode of hypotension that occurred an hour before admission. Patient history and chronologic course of events strongly suggest the role of ESWL in the genesis of abdominal aorta rupture.

Aged↗
PubMed2000

[Chronic pelvic pain in women and prevalent orthostatic work. Preliminary results of a study on health staff of the surgical field].

BACKGROUND: The purpose of this research is to estimate the causal and/or pre-existing causal influence of some working factors, such as the standing (position) in pelvic pain syndrome, in relation to the reduction in working performance. METHODS: The research was carried out by means of an inclusive questionnaire, the purpose being to analyse anamnestic and working information. The questionnaire was proposed to a group of female sanitary staff selected in relation to their working activity. RESULTS: Examination of the questionnaire shows prominently the association between pelvic pain and orthostatic working activity, kept not below 4-6 hours each duty. In fact, 70% of the people selected have reported this mutual relationship. CONCLUSIONS: Working activities in the orthostatic position can produce pelvic pain, whose origin and intensity seem to be related to extended orthostatic working activity. The mechanism by which the upright position can produce an outbreak of pelvic pain in women seems to be linked to the compression on abdominal vessels, with slowing-down and reduction of the hematic uterine discharge.

Chronic Disease↗