Biomedical subjects

S Quaglini

Publications and source records attributed to S Quaglini.

54 records · Page 3Linked to original sources

PubMed1994

[Recovery time from myocardial ischemia induced by exercise test: correlation with duration of ischemia during the test and with the extent of coronary disease].

BACKGROUND: Aim of this study was to evaluate the factors affecting the duration of the recovery time (RT) after a positive exercise stress test and to define its relationship with the extent of coronary artery disease (CAD). METHODS: We studied 109 consecutive patients with a positive exercise test and proven coronary disease. RESULTS: RT was neither related to the severity of CAD, nor to exercise duration, rate-pressure product at the end of the exercise and maximum ST segment depression. A significant linear relationship was found between RT and the time of ischemia during exercise (IT) (r = 0.66, p < .001). This relationship was analyzed separately in patients (pts) with advanced (Group I) and in pts with less severe CAD (Group II). The regression line of the data showed a similar slope but a higher y-axis intercept in Group I than in Group II (p < .05). The RT/IT ratio was in fact significantly higher in Group I than in Group II (3.0 +/- 1.3 vs 1.7 +/- 0.7, p < .0001). Discriminant analysis was performed to predict the presence of advanced CAD: using the RT/IT ratio instead of RT correct classification rate of the model increased from 81.4 to 86.7%, predictive accuracy from 73.7 to 85.3% and true negative rate from 85.3 to 87.4%. CONCLUSIONS: These results suggest that the normalization of the recovery time by time of ischemia during the test provides a simple and useful index for the prediction of the extent of coronary artery disease.

Coronary Angiography↗

PubMed1994

Use of recombinant human erythropoietin after bone marrow transplantation in pediatric patients with acute leukemia: effect on erythroid repopulation in autologous versus allogeneic transplants.

We carried out a pilot study on the use of recombinant human erythropoietin (rHuEPO) in children undergoing allogeneic or mafosfamide-purged autologous BMT for ALL or AML. rHuEPO was administered intravenously at a dose of 75 U/kg/day for 30 days after transplant. Ten rHuEPO-treated patients receiving allogeneic BMT and 10 given autologous BMT were compared with 15 allogeneic and 10 autologous historical controls. Endogenous EPO production was appropriate for the degree of anemia after autologous BMT. In these patients, rHuEPO did not accelerate erythroid repopulation and did not modify transfusion requirements. With allogeneic BMT, erythroid marrow activity increased faster in patients given rHuEPO than in controls and resulted in higher red cell production, the mean reticulocyte count on day +30 being 187 +/- 51 x 10(9)/l in treated patients versus 107 +/- 63 x 10(9)/l in controls (p < 0.01). The total number of RBC units administered was 1.7 +/- 1.3 in the rHuEPO group versus 5.1 +/- 3.0 in the control group (p < 0.001). The total number of platelet transfusions was 4.0 +/- 2.3 for patients given allogeneic BMT and receiving rHuEPO versus 8.4 +/- 6.8 for historical controls (p < 0.05) whereas it was similar in rHuEPO-treated and control autologous BMT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1993

Disposition of high-dose busulfan in pediatric patients undergoing bone marrow transplantation.

We studied the pharmacokinetics of busulfan (16 mg/kg) in 16 pediatric patients affected by malignant and nonmalignant disorders between 6 months and 19 years of age (mean +/- SD, 5.7 +/- 6.5 years) who were undergoing allogenic (15 patients) and autologous (one patient) bone marrow transplantation. In all children, the conditioning regimen consisted of busulfan given orally at a dose of 1 mg/kg every 6 hours for 16 doses (total dose, 16 mg/kg), associated with other drugs. The pharmacokinetics of busulfan was studied during the 6-hour dosing interval on the third day of therapy by use of a high-performance liquid chromatographic assay. The value for the time to reach maximum concentration, expressed as mean +/- SD, was 1.1 +/- 0.5 hour; maximum concentration was 609.6 +/- 225.3 ng/ml; steady-state concentration was 358.9 +/- 135.5 ng/ml; area under the plasma concentration-time curve was 2153.6 +/- 813.1 ng.hr/ml; oral clearance was 0.535 +/- 0.226 L/hr/kg; and half-life was 2.4 +/- 0.8 hours. Age-related differences in busulfan disposition were observed. The mean busulfan oral clearance in a group of 10 patients with an age range from 6 months to 3 years was 0.619 L/hr/kg, whereas six patients whose ages ranged from 7 to 19 years had a oral clearance of 0.396 L/hr/kg. The half-lives for busulfan during infancy decrease continuously until early childhood but were prolonged in older children. No significant relationship between systemic exposure to busulfan and drug effect was observed.

Administration, Oral↗

PubMed1993

Acute phase proteins and prognosis in multiple myeloma.

Serum IL-6 levels have been shown to correlate with disease severity and prognosis in patients with plasma cell dyscrasias. Among its pleiotropic actions, IL-6 is also the major regulator of the acute phase response in humans. The possible impact on survival of the major serum acute phase proteins (s.APP) [C-reactive protein (s.CRP), alpha-1-antitrypsin (s.AAT), haptoglobin, acid alpha-1-glycoprotein and alpha-2-macroglobulin (used as control)] was assessed on a population of 103 consecutive, previously untreated myeloma patients. Univariate analysis showed that among the acute phase proteins only s.AAT (P = 0.015) and s.CRP (P = 0.027) were significantly correlated with survival. The multivariate Cox proportional hazard model applied to s.APP and other common parameters showed that s.beta-2-microglobulin (s.b2M), s.calcium, s.creatinine, BM plasma cell percentage, age and s.AAT correlated significantly with survival. Combining s.b2M and s.AAT allowed stratification of myeloma patients: those with low levels of s.b2M (< or = 3 mg/l) and of s.AAT (< or = 3 g/l) presented an excellent prognosis (median survival exceeding 10 years) while those presenting higher values of the two parameters presented a median survival of 2.5 years (P = 0.002).

Acute-Phase Proteins↗

PubMed1993

Splenectomy for patients with myelofibrosis with myeloid metaplasia: pretreatment variables and outcome prediction.

Since according to the early studies, the outcome after splenectomy in the individual patient with myelofibrosis with myeloid metaplasia (MMM) is unpredictable, we assessed retrospectively the pre-intervention characteristics that best predicted adverse events, hematological consequences, and survival in 71 splenectomized MMM patients. The findings indicate that the operative risk of splenectomy for both mortality (8.4%) and morbidity (39.3%) was unpredictable. New hemorrhagic or thrombotic complications occurred in 16.9% of surviving patients and were predicted by age < 50 years, a normal to high platelet count (> 200 x 10(9)/l) and huge splenomegaly (> 16 cm from the costal margin). Massive liver enlargement occurred in 24% of patients and has to be expected in patients splenectomized for transfusion-dependent anemia. Anemia improved substantially in 45% and 52% of patients at 3 months and at 1 year, respectively, and was predicted by severe anemia, low platelet count (< 100 x 10(9)/l) or normal to high white blood cell (WBC) count (> 4 x 10(9)/l). Survival from splenectomy was superior in patients < 45 years with WBC < 10 x 10(9)/l count. An unexpectedly high rate of blastic transformation was observed. It accounted for 42.8% of the deaths. The results suggest trials for prophylactic cytoreductive treatment in young patients and when platelet count is normal to increased. Further study is needed for elucidating the possible role played by splenectomy in inducing blastic transformation.

Adult↗

PubMed1991

GAMEES: a probabilistic environment for expert systems.

This paper describes GAMEES (Graphical Modelling Environment for Expert Systems), an interactive graphical environment for building and processing Belief Networks and Influence Diagrams. We review the existing systems designed for analogous purposes, and, after a brief introduction to Belief Networks and Influence Diagrams, we describe the graphical interface, discuss algorithms for probabilistic inference on these networks and illustrate the current implementation of GAMEES. The system has been designed for being integrated within wider expert systems and actually it is part of the Therapy Advisor module within an expert system for the management of anemic patients.

Algorithms↗

PubMed1990

Relevance of class, molecular weight and isoelectric point in predicting human light chain amyloidogenicity.

The ability to predict the amyloidogenicity of certain light chains may facilitate an earlier diagnosis of AL amyloidosis and, possibly, lead to more effective treatment. Using current methods, available in clinical chemistry laboratories, we assessed the class, the relative molecular mass (Mr) and the isoelectric point of urinary monoclonal light chains from 35 patients with AL amyloidosis (A+) and 51 without amyloidosis (A-). The light chain class (LCC) was lambda in 77% and 45% of A+ and A- patients, respectively. Light chain fragments (LCF) with low Mr (12-18 x 10(3) were detected in the urine of 30/35 A+ patients and in 15/51 A- ones. The mean (SD) isoelectric point (pI) of A+ light chains was 4.8 (1.1) while in A- patients it was 6.2 (1.6). Univariate analysis showed significant differences between the two groups for the three parameters. Discriminant analysis gave a function which allowed a correct allocation of 81% of the cases between the two groups.

Amyloidosis↗

PubMed1989

Relative iron deficiency in hereditary spherocytosis.

Seventy-three patients with hereditary spherocytosis (HS) (58 nonsplenectomized, 15 splenectomized) were studied to evaluate iron status and the adequacy of iron availability for erythropoiesis. Splenectomized patients, who had hemoglobin levels in the normal or upper normal range, had higher levels of serum iron, transferrin saturation, and serum ferritin than normal matched controls and normal zinc protoporphyrin (ZnPP) levels. On the contrary, nonsplenectomized patients presenting with mild to severe anemia had higher red cell ZnPP concentrations than both splenectomized subjects and matched normal controls. ZnPP in nonsplenectomized patients correlated inversely with Hb concentration, mean corpuscular volume (MCV), mean red cell hemoglobin concentration (MCHC), transferrin saturation, and serum iron, and directly with reticulocyte count. At multiple regression analysis only Hb concentration was a significant explanatory variable for high ZnPP. The authors conclude that a number of nonsplenectomized HS patients have relative iron deficiency primarily because of expansion of erythropoiesis caused by anemia.

Adolescent↗

PubMed1988

A performance evaluation of the expert system ANEMIA.

This paper reports the results of an evaluation study of the current level of performance given by ANEMIA, a knowledge-based consultation system addressing the clinical problem of managing anemic patients. ANEMIA was developed on a mainframe using the AI programming scheme EXPERT and then translated into a version running on a personal computer. At present the system is able to provide assistance in the diagnosis and management of 65 disease entities. After extensive local testing of accuracy, completeness, and consistency of the knowledge base included into ANEMIA, we designed a study to evaluate whether the system is able to appropriately mirror also the reasoning of well-known hematologists other than those who provided the knowledge. We were also interested in testing whether there were conflicting opinions among hematologists. Thus, we designed a validation study in which ANEMIA's performance could be compared with that of six hematologists and the interexpert consensus evaluated. ANEMIA's overall performance was judged acceptable in 87% (26/30) of the cases, while expert evaluators agreed with their colleagues in 90% (27/30) of them. A low interexpert consensus was found: considering the ratings given by different hematologists to the same ANEMIA performance, complete agreement occurred only 47% of the time.

Adult↗

PubMed1986

ANEMIA: an expert consultation system.

Anemia is a knowledge-based consultation program for anemic states. It has been built using an artificial intelligence programming scheme, called EXPERT, which was developed at Rutgers University. At present, ANEMIA is able to provide assistance in the diagnosis and management of 64 disease entities. They include iron deficiency anemias, anemias due to chronic disorders, thalassemias, hemolytic anemias, arigenerative anemias, and a few other miscellaneous conditions. ANEMIA was tested against a data base of 220 retrospective and 100 new cases and the overall accuracy in the diagnostic performance was pretty good. Our intent is that ANEMIA ultimately will be able to serve as surrogate for the hematologist with the nonhematologist physician-user.

Anemia↗

PubMed1985

Classification of anaemia on the basis of ferrokinetic parameters.

Quantitative information on abnormalities of erythropoiesis and mechanisms of anaemia has been obtained in 136 anaemic patients by means of ferrokinetic studies. To derive a functional classification of anaemia based on ferrokinetic parameters, agglomerative hierarchical cluster analysis and principal coordinate analysis were utilized as techniques for unsupervised classification. Two main clusters were found and named anaemia with low potential erythropoiesis and with high potential erythropoiesis, since the most discriminant parameter between them was total erythroid iron turnover, a measure of total erythropoietic activity. A value of total erythropoiesis equal to 4 times the normal was found to discriminate these two types of anaemia in 94% of cases. Within the group with low potential erythropoiesis, three clusters showing different qualitative disturbances of erythropoiesis were singled out. Among patients with high potential erythropoiesis, two clusters were found. A value of effective erythropoiesis equal to 2.5 times the normal was shown to have a high discriminant power between these clusters. This threshold level distinguished between patients having ineffective erythropoiesis or peripheral haemolysis as the major mechanism of anaemia. The present functional classification of anaemia provides a complete picture of the different pathogenetic mechanisms and may represent the basis for a more rational diagnostic approach to erythroid disorders.

Adolescent↗

PubMed1983

Biologic and clinical significance of red cell ferritin.

Red cell ferritin was measured in normal subjects and patients with disorders of iron metabolism, inflammation, liver dysfunction, impaired hemoglobin synthesis, and increased red cell turnover by means of radioimmunoassays with antibodies to liver (basic) and heart (acidic) ferritins. The normal mean values for basic and acidic ferritin were 8.9 and 22.7 altogram (ag)/cell, respectively. The red cell ferritin content reflected changes occurring in tissues both in iron deficiency and iron overload. Basic ferritin was more closely related to the body iron status than acidic ferritin, and the acidic/basic ferritin ratio was increased in iron deficiency and decreased in iron overload. The major factor determining the red cell ferritin content appeared to be the transferrin saturation, that is, the distribution of iron between monoferric and diferric transferrin. This is in keeping with recent data indicating a competitive advantage of diferric transferrin in delivering iron to erythroid cells. In addition, the red cell ferritin content was increased in thalassemic patients with normal iron status, appearing to be inversely related to the rate of hemoglobin synthesis. The determination of red cell ferritin, based on a commercially available basic ferritin assay, can have clinical application. It can be used for evaluating the adequacy of the iron supply to the erythroid marrow, particularly in patients with increased red cell turnover. Moreover, it may be useful in evaluating the body iron status in patients with hemochromatosis and liver disease.

Adolescent↗

PubMedDate not supplied

Supporting tools for guideline development and dissemination.

This paper describes a methodology for representing clinical practice guidelines and facilitating their introduction into the medical routine. Since this methodology can be exploited in a www environment, it can represent the basis for sharing clinical guidelines both between different institutions and between human and software agents cooperating within a clinical context. In addition, the proposed guideline formalization is intended to deal with patient and organization preferences. This goal is achieved by augmenting the guideline with decision analytic models and by linking the guideline with an organizational model of the clinical setting. The designed framework allows guideline development, tailoring and implementation, real-time access to the guideline prescriptions and guideline validation.

Algorithms↗

PubMedDate not supplied

An influence diagram for assessing GVHD prophylaxis after bone marrow transplantation in children.

Graft-versus-host disease (GVHD) represents one of the major complications of allogeneic bone marrow transplantation (BMT). Nevertheless, the occurrence of mild GVHD could be desirable in high-risk leukemic patients, due to a relapse-preventing effect known as the graft-versus-leukemia (GVL) effect. Given that different prophylactic interventions are available to prevent GVHD development, the decision problem consists in assessing both type and dosage of the drugs in order to avoid or induce GVHD, according to the specific patient's condition. The decision problem can be represented and solved by using an influence diagram. The choice of this formalism allows using new available methods for building and updating the model of the decision problem. The qualitative structure of the model and the conditional probabilities were first derived by combining literature results with a medical expert's judgement. More specifically, probabilities were initially assigned as ranges rather than as point values. Then, conditional probabilities were updated, by using a learning algorithm, as new cases became available. The authors analyzed 50 cases of pediatric patients affected by either malignant or nonmalignant diseases, undergoing BMT and receiving GVHD prophylaxis. They used the first 25 cases to adjust the initially assigned conditional probabilities, then checked the model obtained on the remaining patients. The overall performance for GVHD prediction was about 80%.

Algorithms↗

PubMedDate not supplied