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Biomedical subjects

R Bellazzi

Publications and source records attributed to R Bellazzi.

68 records · Page 4Linked to original sources
PubMed1979

Insulin receptors in psoriasis.

We have demonstrated how in psoriasis, irrespective of any diabetic family history, there exists a state of hyperinsulinism with a decreased resistance to insulin, which is aggravated by obesity. Since reviewing the latest studies concerning diabetes at the receptor level, we have carried out a comparative study dealing with insulin receptors in lymphocytes in homogeneous groups of normal, obese, and psoriatics of normal weight and overweight. We have also made a comparison regarding the behaviour of the receptors in these various metabolic states.

Blood Glucose↗
PubMedDate not supplied

Binding and degradation of 125I-insulin in human erythrocytes. Comparative studies with hemolysate and membranes.

Insulin degradation in human erythrocytes obtained from normal subjects is studied. Under the experimental conditions used, insulin binding and insulin degradation are strictly correlated, and no degrading activity is released in incubation medium. Comparative analysis of hemolysate and membranes shows that hemolysate possesses a definite insulin-degrading activity which is not linked to the hemoglobin molecule; the km of this enzymatic activity is of the same order of magnitude as that reported in other cells. At the concentration and in the condition used in this study, membranes degrade insulin at a lower rate than hemolysate.

Erythrocyte Membrane↗
PubMedDate not supplied

Learning from biomedical time series through the integration of qualitative models and fuzzy systems.

Our work deals with a method for the identification of the dynamics of nonlinear (patho-)physiological systems by learning from data. The key idea which underlies our approach consists in the integration of qualitative modeling methods with fuzzy logic systems. The major advantage which derives from such an integrated framework lies in its capability both to represent the structural knowledge of the system at study and to determine, by exploiting the available experimental data, a functional approximation of the system dynamics that can be used as a reasonable predictor of the patient's future state. We have successfully applied our method in the identification of the intracellular kinetics of thiamine from data collected in the intestine cells.

Artificial Intelligence↗
PubMedDate not supplied

Qualitative models and fuzzy systems: an integrated approach for learning from data.

This paper presents a method for the identification of the dynamics of non-linear systems by learning from data. The key idea which underlies our approach consists of the integration of qualitative modeling techniques with fuzzy logic systems. The resulting hybrid method exploits the a priori structural knowledge on the system to initialize a fuzzy inference procedure which determines, from the available experimental data, a functional approximation of the system dynamics that can be used as a reasonable predictor of the patient's future state. The major advantage which results from such an integrated framework lies in a significant improvement of both efficiency and robustness of identification methods based on fuzzy models which learn an input output relation from data. As a benchmark of our method, we have considered the problem of identifying the response to the insulin therapy from insulin-dependent diabetic patients: the results obtained are presented and discussed in the paper.

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

[Diffusive and convective treatments in the clinical practice: observation study of the Pavia district nephrology group].

UNLABELLED: PURPOSE. Although convective treatments are widely used, there is no evidence that they can improve patient survival or hospitalizations nor clinical criteria indicating which patients could benefit from them. This study was carried out to evaluate the dialysis modality distribution and the clinical criteria used in choosing the dialysis therapy by the four dialysis Centers in the district of Pavia, a district characterized by a quite homogeneous population. METHODS: We evaluated age, gender, body mass index (BMI), time on dialysis, number of sessions per week, dialysis duration, dialysis modality, criteria used in choosing dialysis therapy, vascular access (VA), Kt/V, and the number of hypotensive episodes. RESULTS: Two hundred and seventy-two patients were enrolled in the study. Mean age was 67.3 +/- 12 yrs, BMI was 26.3 +/- 6.1, dialytic age was 5.49 +/- 5.5 yrs, Kt/V was 1.4 +/- 0.3, mean session time was 238 min. Fifty-two patients (19.2%) were on a convective treatment. Age, BMI, time on dialysis, dialysis duration and number of sessions per week were no different between convective treatment patients and diffusive treatment patients. Kt/V was significantly different between convective and diffusive methods (1.55 +/- 0.37 vs 1.4 +/- 0.28, p<0.05). Convective treatments were prescribed for cardiovascular (CV) instability by the nephrologists from the Pavia district in the majority of patients (90.9%). There was no difference in hypotensive episodes between convective and diffusive methods. CONCLUSIONS: Our study demonstrated that lacking clinical evidence indicating an improvement in the long-term outcome with convective techniques, nephrologists in the Pavia district choose this type of dialysis treatment to ameliorate CV stability in uremic patients.

Aged↗
PubMedDate not supplied

[From the Mailing List SIN: expected and unexpected professional risks for the nephrologists--reflections from an outbreak of Burkholderia cepacia bacteremia in a hemodialysis unit].

An outbreak of bacteremia in 20 hemodialysed patients who developed central venous catheter (CVC) infection related to Burkholderia cepacia is reported, introducing medical and professional responsibilities in nephrology units. The cepacia was documented in the blood stream, in the CVC biofilm, in the water supply and in the distribution. This and other confounding factors delayed the identification of the contamination source. Finally, it was isolated, clonally identical to that found in the blood stream, from ammonium chloride solution used to disinfect the skin and distributed in a sterile disposable kit. Burkholderia cepacia was clonally different in blood with respect to water. The possible differing responsibilities in the organizational steps of nephrology activity are discussed.

Ammonium Chloride↗
PubMedDate not supplied

[The Dialysis Outcomes and Practice Patterns Study (DOPPS): results of the Italian cohort].

BACKGROUND: The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective, longitudinal, observational study examining the relationship between dialysis unit practices and outcomes for hemodialysis (HD) patients in seven developed countries France, Germany, Italy, Spain, United Kingdom, Japan and the United States. Results of the DOPPS in Italy are the subject of this report. METHODS: A national representative sample of 20 dialysis units (21 in Germany) was randomly selected in each of the European DOPPS countries (Euro-DOPPS). In these units, the HD in-center patients were included on a facility census, and their survival rates continuously monitored. A representative sample of incident (269 in Italy, 1553 in the Euro-DOPPS) and prevalent (600 in Italy, 3038 in the Euro-DOPPS) patients was randomly selected from the census for more detailed longitudinal investigation with regard to medical history, laboratory values and hospital admission. RESULTS: Comparing the Italian and Euro-DOPPS cohorts we found comparable mean age for prevalent patients (61.4 vs. 59.5 yrs), but incident patients were older in Italy. Italian prevalent patients had less cardiovascular disease, more satisfactory nutritional status and more frequent use of native vascular access. These data were associated with a comparable mortality (15.7 vs. 16.3 deaths/100 patient yrs), but morbidity was lower in Italy. Kt/V levels were comparable in the two cohorts (1.32 vs. 1.37), but 35% of Italian patients showed a Kt/V below the recommended target. Moreover, hemoglobin levels were below 11 g/dL in 60% of Italian patients. CONCLUSIONS: The DOPPS results bring to light several positive aspects and the opportunity for further possible improvements for Italian patients, but at the same time highlight some critical points that could represent a risk for dialysis quality.

Aged↗
PubMedDate not supplied

Mathematical modeling of erythropoietin therapy in uremic anemia. Does it improve cost-effectiveness?

This paper describes the improvements in r-HuEPO therapy of uremic patients that may be obtained by using a mathematical model of patient response together with a delivery control strategy derived from the theory of industrial control. A mathematical model of r-HuEPO action is presented, and its applicability to dialytic patients is shown. Moreover, a new statistical technique for identifying the parameters of the mathematical model analyzing a patient population is summarized, and a control strategy for r-HuEPO delivery in uremic patients based on a Fuzzy Set Controller is introduced. Some results obtained from simulation, are presented.

Anemia↗
PubMedDate not supplied

A Web-based system for the intelligent management of diabetic patients.

We describe the design and implementation of a distributed computer-based system for the management of insulin-dependent diabetes mellitus. The goal of the system is to support the normal activities of the physicians and patients involved in the care of diabetes by providing them with a set of automated services ranging from data collection and transmission to data analysis and decision support. The system is highly integrated with current practices in the management of diabetes, and it uses Internet technology to achieve high availability and ease of use. In particular, the user interaction takes place through dynamically generated World Wide Web pages, so that all the system's functions share an intuitive graphic user interface.

Blood Glucose Self-Monitoring↗