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Biomedical subjects

G Gini

Publications and source records attributed to G Gini.

14 recordsLinked to original sources

Validation of counter propagation neural network models for predictive toxicology according to the OECD principles: a case study.

The OECD has proposed five principles for validation of QSAR models used for regulatory purposes. Here we present a case study investigating how these principles can be applied to models based on Kohonen and counter propagation neural networks. The study is based on a counter propagation network model that has been built using toxicity data in fish fathead minnow for 541 compounds. The study demonstrates that most, if not all, of the OECD criteria may be met when modeling using this neural network approach.

Animal Use Alternatives↗

Combined administration of alpha-erythropoietin and filgrastim can improve the outcome and cost balance of autologous stem cell transplantation in patients with lymphoproliferative disorders.

We compared the use of G-CSF plus EPO in a group of 32 multiple myeloma and lymphoma patients with historical controls receiving G-CSF alone. Haemopoietic reconstitution was significantly faster in patients receiving G-CSF+EPO (group B), with a median time of 10 days to achieve an ANC count >0.5 x 10(9)/l, compared to 11 days in the historical group (A). The median duration of severe neutropenia (ANC count <100/ml) was significantly shorter in group B compared to group A; platelet counts >20 x 10(9) and >50 x 10(9)/l were achieved at days + 13 and + 17, respectively in group B, compared to days + 14 and + 24, respectively, in group A (P = 0.015, 0.002) patients. The transfusion requirement was reduced in group B, with 0 (0-6) RBC units and 1 (0-5) platelet unit transfused in group B vs 2 RBC (0-9) and 2 platelet units (0-8) in group A. Median days of fever, antibiotic therapy and hospital stay were reduced in group B (9.5 days vs 22). The mean cost of autotransplantation per group A patient was 23,988 Euro, compared with 18,394 Euro for a group B patient. Our study suggests that the EPO + G-CSF combination not only accelerates engraftment kinetics, but can also improve the clinical course of ASCT.

Adult↗

Predicting logP of pesticides using different software.

We compared experimental and calculated logP values using a data set of 235 pesticides and experimental values from four different sources: The Pesticide Manual, Hansch Manual, ANPA and KowWin databases. LogP were calculated with four softwares: HyperChem, Pallas, KowWin and TOPKAT. Crossed comparison of the experimental and calculated values proved useful, especially for pesticides. These are harder to study than simpler organic compounds. Structurally they are complex, heterogeneous and similar to drugs from a chemical point of view. They offer an interesting way to verify the goodness of the different methods. Other studies compared several logP predictors using a single set of experimental values taken as a reference. Here we discuss the utility of the different logP predictors, with reference to experimental data found in different databases. This offers three advantages: (1) it avoids bias due to the assumption that one single data set is correct; (2) a given predictor can be developed on the same data set used for evaluation; (3) it takes account of experimental variability and can compare it with the predictor's variability. In our study Pallas and KowWin gave the best results for prediction, followed by TOPKAT.

1-Octanol↗

Incidence and clinical characteristics of posttransplant lymphoproliferative disorders: report from a single center.

In the period 1973-1998, among 2139 allograft recipients treated with standard immunosuppression, posttransplant lymphoproliferative disorders (PTLD) developed in 19 patients (0.9%): one plasmacytic hyperplasia, two polymorphic PTLD, one myeloma, and 15 lymphomas. PTLD developed 1 year after transplantation (tx) in 14 patients. Five patients were diagnosed at autopsy, 2 were lost to follow up, 3 died before therapy could be instituted, and 1 patient has just started chemotherapy. Of the 8 evaluable patients, 2 received acyclovir and are alive in complete remission (CR) and 6 received chemotherapy +/- surgery. Of these 6, 4 died of lymphoma and/or infection, 1 died of unrelated causes in CR, and 1 is alive in CR. PTLD is a severe complication of tx, usually running an aggressive course which may preclude prompt diagnosis and treatment. Nevertheless, therapy is feasible and must be tailored on the histologic subtype. Seventy-four percent of patients were diagnosed with late-onset PTLD stressing the need for long-term follow up.

Acyclovir↗

Computational predictive programs (expert systems) in toxicology.

The increasing number of pollutants in the environment raises the problem of the toxicological risk evaluation of these chemicals. Several so called expert systems (ES) have been claimed to be able to predict toxicity of certain chemical structures. Different approaches are currently used for these ES, based on explicit rules derived from the knowledge of human experts that compiled lists of toxic moieties for instance in the case of programs called HazardExpert and DEREK or relying on statistical approaches, as in the CASE and TOPKAT programs. Here we describe and compare these and other intelligent computer programs because of their utility in obtaining at least a first rough indication of the potential toxic activity of chemicals.

Animals↗

A serial model for computer assisted medical diagnosis.

In this paper we discuss a simple model for an interactive consultation system for medical applications. That system was developed to provide consultative advice on diagnosis of arthritis, but it could be easily applied to a different class of diseases. We examine in particular how the determination of the appropriate sequence of diagnostic tests that have to be performed on the patient can be optimised by the use of a decision table, in which the medical knowledge is shown. We begin with a review of features which were seen to be essential to a consultation system for medical applications and we suggest how these requirements imply program design criteria. This is followed by a formal explanation of the proposed model and its fundamental assumptions. The last part of the paper is then devoted to a report of our experience with the experimental computer system.

Arthritis↗

Tuning neural and fuzzy-neural networks for toxicity modeling.

The need for general reliable models for predicting toxicity has led to the use of artificial intelligence. We applied neural and fuzzy-neural networks with the QSAR approach. We underline how the networks have to be tuned on the data sets generally involved in modeling toxicity. This study was conducted on 562 organic compounds in order to establish models for predictive the acute toxicity in fish.

Animals↗

Predictive carcinogenicity: a model for aromatic compounds, with nitrogen-containing substituents, based on molecular descriptors using an artificial neural network.

A back-propagation neural network to predict the carcinogenicity of aromatic nitrogen compounds was developed. The inputs were molecular descriptors of different types: electrostatic, topological, quantum-chemical, physicochemical, etc. For the output the index TD50 as introduced by Gold and colleagues was used, giving a continuous numerical parameter expressing carcinogenicity. From the tens of descriptors calculated, principal component analysis enabled us to restrict the number of parameters to be used for the artificial neural network (ANN). We used 104 molecules for the study. An Rcv2 = 0.69 was obtained. After removal of 12 outliers, a new ANN gave an Rcv2 of 0.82.

Carcinogenicity Tests↗

[Randomized study of the antiemetic efficacy of alizapride versus alizapride + dexamethasone].

We made a study on patients suffering from neoplasias treated with cisplatinum to compare antiemetic efficacy of alizapride or associated to dexamethasone. We divided patients in two groups. We somministred alizapride alone to the first group and alizapride plus dexamethasone to the second one. We evaluated presence or absence of emesis, its intensity and eventual tossic effects due to the drugs through an autocompilative questionnaire given to the patients. Our results didn't show important statistical differences between the two groups, though association with dexamethasone gets better emesis control. Alizapride anyway, didn't present important collateral effects, particularly extrapyramidal ones.

Antiemetics↗