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1.
J Hazard Mater ; 474: 134657, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-38838526

ABSTRACT

The ceramic industry is a production sector that can efficiently recycle its own processing residues, achieving a reuse index of almost 100%. Recently, the range of waste from other industrial sectors that can be used as secondary raw materials in ceramic bodies has expanded. However, such an expansion potentially introduces hazardous components. This study aimed to quantitatively assess the efficiency of inertising hazardous elements (HEs) through ceramisation. The ceramics were characterised through XRPD, SEM-EDS and leaching tests to determine their leaching behaviour and the mechanisms of element immobilisation in neoformation phases during the ceramisation process. The results indicate high immobilisation efficiency for Ba, Co, Cr, Cu, Pb, Sb, Sn and Zn. However, Mo is the main element of concern owing to its poor retention in ceramic bodies. This is likely due to the formation of oxyanionic complexes that are difficult to immobilise in silicate matrices. In addition, the ceramic bodies exhibit substantial differences that appear to be associated with variations in pseudo-structural components and the degree of polymerisation of their vitreous phase.

2.
Chem Res Toxicol ; 30(5): 1145-1156, 2017 05 15.
Article in English | MEDLINE | ID: mdl-28398727

ABSTRACT

In vitro safety assessment in early drug discovery represents an important step to detect potential safety-related liabilities. It reduces late stage attrition and allows candidate optimization. In this study, we report on the use of the LogDBPL assay (a recently published assay for the determination of drug distribution coefficients between an aqueous phase and porcine brain polar lipids extract) for phospholipidosis (PLD) risk evaluation. The LogDBPL parameter was first compared to the effective permeability in the parallel artificial membrane permeability assay (PAMPA), previously reported as correlating with PLD risk. Subsequently, the LogDBPL for a set of 234 drugs with known PLD effect was measured, representing the largest data set of LogDBPL data published so far, and the correlation with phospholipid accumulation was further investigated. In addition, a comparison with other in silico methods based on physicochemical parameters is reported. Results showed that LogDBPL is an efficient descriptor to assess PLD risk, especially when corrected using the pKa value of compounds, being superior to the distribution coefficient in octanol, LogDOCT, and the effective permeability in the PAMPA assay. A multivariate statistical analysis approach was finally used to better define the intrinsic features of LogDBPL, whose effect proved to be highly similar to that of volume of distribution in silico when used to predict brain distribution and PLD.


Subject(s)
Brain/metabolism , Lipidoses/chemically induced , Phospholipids/metabolism , Animals , Drug-Related Side Effects and Adverse Reactions , Pharmaceutical Preparations/classification , Principal Component Analysis , Swine
3.
Environ Pollut ; 212: 559-564, 2016 May.
Article in English | MEDLINE | ID: mdl-26977961

ABSTRACT

Ethylenediurea (EDU) is a common research tool for investigating ozone impacts on vegetation, although the role of different application routes (foliar spray vs soil drench) on EDU persistence in the leaves is unknown. We quantified EDU concentrations in leaves of the O3-sensitive Bel-W3 cultivar of tobacco treated with EDU as either foliar spray or soil drench. Foliar EDU concentrations were measured by Q-TOF LC/MS. When EDU was applied as foliar spray, 1 h was enough for reaching a measurable concentration within the leaf. EDU concentration increased over the 21-day period when the leaf was not washed after the application (treatment #1), while it decreased when the leaf was washed after the application (treatment #2). These results suggest that: a) dry deposition of EDU onto the leaf surface was gradually absorbed into the unwashed leaf, although the mechanisms of such uptake were unclear; b) concentration of EDU was decreased quickly (-35%) during the first 24 h from application and more slowly during the following three days (-20%) in the washed leaves. Degradation did not involve enzymatic reactions and was not affected by the presence of ROS. When EDU was applied as soil drench, foliar concentrations increased over time, likely due to adsorption onto soil organic matter and gradual re-solubilization by irrigation water. An analysis of EDU concentration in protoplast and intercellular washing fluid showed that EDU did not enter the cells, but was retained in the apoplast only. Possible implications of EDU in the apoplast and recommendations for EDU application are discussed.


Subject(s)
Nicotiana/metabolism , Phenylurea Compounds/metabolism , Plant Leaves/metabolism , Aerosols , Air Pollutants/metabolism , Ozone/metabolism , Soil , Time Factors
4.
SAR QSAR Environ Res ; 27(3): 221-244, 2016 Mar.
Article in English | MEDLINE | ID: mdl-30950653

ABSTRACT

Five in silico principal properties (PPs) for 218 heterocyclic cations and four PPs for 38 organic and inorganic anionic counterparts of ionic liquids (ILs) were derived by the VolSurf+ approach. VolSurf+ physicochemical descriptors take into account several cationic structural features of ILs such as heterocyclic aromatic and non-aromatic cationic cores, alkyl chain length, presence of oxygen atoms in the substituents as well as the properties of a wide variety of inorganic and organic anions. Combination of these cation and anion PPs can provide descriptors for over 8000 ILs, thus allowing the development of QSPR models for IL cytotoxicity (IPC-81 rat cell line) and enzyme toxicity (acetylcholinesterase inhibition). The adoption of a Partial Least Squares approach, relating PPs and toxicities, provided affordable predictions for ILs in both learning and external validation sets, implying the possibility to extend the predictive model to a set of 520 ILs. This allows us to establish priorities in selecting ILs for experimental hazard assessment as required by the REACH regulation.

5.
Curr Med Res Opin ; 30(3): 447-61, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24168104

ABSTRACT

BACKGROUND: Throughout Europe, physicians face similar challenges in non-small cell lung cancer (NSCLC) management, but comprehensive international information on usual clinical practice is lacking so the burden of NSCLC is not fully understood. METHODS: This multinational, multicentre, non-interventional study (NCT00831909) was conducted in eight European countries. Patients with confirmed NSCLC were consecutively enrolled from January to March 2009 and followed for 12 months or until death. Information was collected on patient and disease characteristics, diagnosis and treatment patterns, and clinical outcomes. Spontaneously reported adverse events (AEs) were also recorded. RESULTS: Data were available for 3508 patients. Most patients (77.5%) were male, median (range) age was 65.0 years (21.6-90.7), the majority of patients had a World Health Organization performance status of ≤1 (74.7%), and 10.8% were never smokers. The most prevalent histologies were adenocarcinoma (43.8%) and squamous-cell carcinoma (29.4%). Most patients presented with advanced disease (11.6% with stage IIIA, 18.7% with stage IIIB, 48.6% with stage IV). In stage IV disease, median progression-free survival and overall survival (months) by first-line treatment cluster were platinum regimens: 6.5, 10.8; non-platinum regimens: 4.3, 8.5; regimens with bevacizumab 8.7, 12.9; investigational regimens: 5.6, 10.8; best supportive care: 5.4, 6.6. The most frequently reported severe (Common Terminology Criteria for Adverse Events v3.0>2) AEs were blood/bone marrow (16.0%) and pulmonary/upper respiratory (7.8%). Key limitations of this study related to its non-interventional nature and wide regional focus; for example, achieving a representative sample of the overall NSCLC population, variation in recruitment between countries, and data based on information from medical records derived from routine visits. CONCLUSIONS: The Epidemiological Study to Describe NSCLC Clinical Management Pattern in Europe-Lung (EPICLIN-Lung) study provides new insights into the descriptive patterns and clinical management strategies for NSCLC across Europe, and how they affect patient outcomes.


Subject(s)
Carcinoma, Non-Small-Cell Lung/therapy , Lung Neoplasms/therapy , Adult , Aged , Aged, 80 and over , Europe , Female , Humans , Male , Middle Aged , Prospective Studies , Young Adult
6.
Curr Med Res Opin ; 30(3): 463-70, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24188056

ABSTRACT

BACKGROUND: There is a lack of data on health resource assessment in non-small cell lung cancer (NSCLC) to inform clinical decision-making. The Epidemiological Study to Describe NSCLC Clinical Management Pattern in Europe-Lung (EPICLIN-Lung) study provides information on healthcare resource utilization associated with different NSCLC treatment strategies in real-life clinical settings. METHODS: This multinational, multicenter, non-interventional study (NCT00831909) was conducted in eight European countries in 2009-2010. Patients with confirmed NSCLC were enrolled and followed for 12 months or until death. Information was collected on patient and disease characteristics, diagnosis and treatment patterns. Healthcare resource utilization was described in relation to diagnostic patterns and treatment received. RESULTS: Data were available for 3508 patients (median age=65.0 years, male=77.6%, Caucasian=98.4%, adenocarcinoma=43.8%, stage IV=48.6%, 10.8% never smoked). The overall mean number of hospitalization days was 16.4 (standard deviation (SD)=18.42). Patients were followed up for a mean of 245.8 (131.4) days. Most patients (96.0%) underwent imaging procedures, most commonly scanning (93.9%). Surgery was associated with a mean of 12.5 (9.33) hospitalization days, with lobectomy and extended procedures (20.3%) being the most common surgery types. Radiotherapy resulted in a mean of 11.6 (14.12) hospitalization days. The majority of radiotherapy was palliative (56.0%), which resulted in fewer (mean 9.5 [11.12]) hospitalization days. Administration of systemic treatment resulted in a mean of 6.5 (8.04) hospitalization days, 1.7 (3.59) visits for disease-related events, 2.3 (1.83) adverse events and 5.4 (5.86) blood-specific resources. The key limitations of this study are those inherent to its non-interventional nature and wide regional focus, and the lack of cost-effectiveness data. CONCLUSIONS: EPICLIN-Lung provides important, Europe-wide information on drivers of healthcare resource use in different treatment strategies for NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/therapy , Health Care Rationing , Lung Neoplasms/therapy , Europe , Hospitalization , Humans
7.
Curr Med Chem ; 19(25): 4306-23, 2012.
Article in English | MEDLINE | ID: mdl-22709009

ABSTRACT

1,4-Dihydropyridines were introduced in the last century for the treatment of coronary diseases. Then medicinal chemists decorated the 1,4-DHP nucleus, the most studied scaffold among L-type calcium channel blockers, achieving diverse activities at several receptors, channels and enzymes. We already described (Ioan et al. Curr. Med. Chem. 2011, 18, 4901-4922) the effects of 1,4-DHPs at ion channels and G-protein coupled receptors. In this paper we continue the analysis of the wide range of biological effects exerted by compounds belonging to this chemical class. In particular, focus is given to the ability of 1,4-DHPs to revert multi drug resistance that, after over 20 years of research, continues to be of great interest. We also describe activities on other targets and the action of 1,4-DHPs against several diseases. Finally, we report and review the interaction of 1,4-DHPs with the hERG channel, transporters and phase I metabolizing enzymes. This work is a starting point for further exploration of the 1,4-DHP core activities on targets, off-targets and antitargets.


Subject(s)
Dihydropyridines/chemistry , Dihydropyridines/pharmacology , Alzheimer Disease/drug therapy , Animals , Antitubercular Agents/chemistry , Antitubercular Agents/pharmacology , Antitubercular Agents/therapeutic use , Atherosclerosis/drug therapy , Cytochrome P-450 Enzyme Inhibitors , Cytochrome P-450 Enzyme System/metabolism , Dihydropyridines/therapeutic use , Drug Resistance, Multiple/drug effects , Humans , Platelet Activating Factor/antagonists & inhibitors , Tuberculosis/drug therapy
8.
Curr Med Chem ; 18(32): 4901-22, 2011.
Article in English | MEDLINE | ID: mdl-22050742

ABSTRACT

Since the pioneering studies of Fleckenstein and co-workers, L-Type Calcium Channel (LTCC) blockers have attracted large interest due to their effectiveness in treating several cardiovascular diseases. Medicinal chemists achieved high potency and tissue selectivity by decorating the 1-4-DHP nucleus, the most studied scaffold among LTCC blockers. Nowadays it is clear that the 1,4-DHP nucleus is a privileged scaffold since, when appropriately substituted, it can selectively modulate diverse receptors, channels and enzymes. Therefore, the 1,4-DHP scaffold could be used to treat various diseases by a single-ligand multi-target approach. In this review, we describe the structure-activity relationships of 1,4-DHPs at ion channels, G-protein coupled receptors, and outline the potential for future therapeutic applications.


Subject(s)
Dihydropyridines/chemistry , Ion Channels/chemistry , Receptors, G-Protein-Coupled/chemistry , Animals , Calcium Channel Blockers/chemistry , Calcium Channel Blockers/pharmacology , Calcium Channels, L-Type/chemistry , Calcium Channels, L-Type/metabolism , Chemistry, Pharmaceutical , Dihydropyridines/pharmacology , Humans , Ion Channels/metabolism , Receptors, G-Protein-Coupled/metabolism , Structure-Activity Relationship
9.
Anal Bioanal Chem ; 397(6): 2131-6, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20358183

ABSTRACT

A recently developed synchrotron-based imaging technique, X-ray diffraction microtomography (XRD-CT), has been applied here for the first time to a complex system, the hydrating Portland cement paste, in order to monitor the evolution of microstructure and phase formation with a 3D non-invasive imaging approach. The ettringite-XRD-peak-based image reconstructions, combined with transmission microtomography (X-microCT) images, allowed to assess the ubiquitous distribution of this phase, which appears early in the hydration process and showed its preferential concentration in the relatively less compact regions of the paste. The comparison of greyscale histograms for cement pastes after 9 and 58 h from hydration showed an increase of ettringite content with age, in agreement with the quantitative Rietveld analysis of the sum patterns. By renormalizing the greyscale histograms to the relative weight fraction, as obtained from Rietveld refinements, a new technique which allows estimation of phase contents with spatial resolution has been developed. The results achievable by combining XRD-CT, X-microCT and Rietveld appear very promising to provide experimental snapshots of the cement hydration process to be compared with results obtained from computer simulations.

10.
Curr Med Chem ; 17(9): 826-46, 2010.
Article in English | MEDLINE | ID: mdl-20156173

ABSTRACT

Many enzymes and proteins are regulated by their quaternary structure and/or by their association in homo- and/or hetero-oligomer complexes. Thus, these protein-protein interactions can be good targets for blocking or modulating protein function therapeutically. The large number of oligomeric structures in the Protein Data Bank (http://www.rcsb.org/) reflects growing interest in proteins that function as multimeric complexes. In this review, we consider the particular case of homodimeric enzymes as drug targets. There is intense interest in drugs that inhibit dimerization of a functionally obligate homodimeric enzyme. Because amino acid conservation within enzyme interfaces is often low compared to conservation in active sites, it may be easier to achieve drugs that target protein interfaces selectively and specifically. Two main types of dimerization inhibitors have been developed: peptides or peptidomimetics based on sequences involved in protein-protein interactions, and small molecules that act at hot spots in protein-protein interfaces. Examples include inhibitors of HIV protease and HIV integrase. Studying the mechanisms of action and locating the binding sites of such inhibitors requires different techniques for different proteins. For some enzymes, ligand binding is only detectable in vivo or after unfolding of the complexes. Here, we review the structural features of dimeric enzymes and give examples of inhibition through interference in dimer stability. Several techniques for studying these complex phenomena will be presented.


Subject(s)
Enzyme Inhibitors/chemistry , Enzymes/chemistry , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Binding Sites , Biomimetic Materials/chemistry , Biomimetic Materials/pharmacology , Dimerization , Enzyme Inhibitors/pharmacology , Enzymes/metabolism , HIV Integrase/chemistry , HIV Integrase/metabolism , HIV Protease/chemistry , HIV Protease/metabolism , Protein Binding
11.
Mini Rev Med Chem ; 9(12): 1379-88, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19929811

ABSTRACT

The diltiazem binding site of L-type calcium channels is the least characterized to date. In this paper, we present some of the available chemotypes that bind to the benzothiazepine binding site: natural compounds, compounds synthesized by varying the benzothiazepine scaffold, and compounds discovered by means of computational approaches.


Subject(s)
Calcium Channel Blockers/chemistry , Diltiazem/analogs & derivatives , Ligands , Binding Sites , Calcium Channels, L-Type/chemistry , Calcium Channels, L-Type/metabolism , Computer Simulation , Diltiazem/chemistry
13.
J Clin Oncol ; 19(22): 4209-15, 2001 Nov 15.
Article in English | MEDLINE | ID: mdl-11709564

ABSTRACT

PURPOSE: To determine whether switching patients from tamoxifen to antiaromatase treatment would prevent some of the relapses or deaths that we assume would occur if tamoxifen were continued. PATIENTS AND METHODS: Three hundred eighty postmenopausal breast cancer patients receiving adjuvant tamoxifen treatment for 3 years were randomized to either continue tamoxifen for 2 more years or to switch to low-dose aminoglutethimide (250 mg daily) for 2 years. RESULTS: At a median follow-up of 61 months (range, 5 to 94 months), 59 events occurred in the tamoxifen group, and 55 occurred in the aminoglutethimide group. More treatment failures at distant sites, such as viscera (P =.02), were observed in the tamoxifen group. Although no differences in disease-free survival between the two groups have emerged so far, a significant trend favors aminoglutethimide in overall survival (P =.005) and breast cancer-specific survival (P =.06). Even if more patients in the antiaromatase group complained of drug-related side effects and more of them discontinued treatment (P =.0001), the number of cardiovascular events and, in general, of life-threatening adverse events was higher in the tamoxifen arm. CONCLUSION: Switching patients from tamoxifen to aminoglutethimide treatment resulted in comparable event-free survival, but longer overall survival was achieved in patients who were switched to aminoglutethimide as compared with those who continued to receive tamoxifen. Should these preliminary results be confirmed by larger studies with a similar design, which are now testing the effectiveness of the new, more active, and tolerable aromatase inhibitors, sequencing tamoxifen with an aromatase inhibitor could become a preferable alternative to tamoxifen alone in early breast cancer patients.


Subject(s)
Aminoglutethimide/therapeutic use , Breast Neoplasms/drug therapy , Enzyme Inhibitors/therapeutic use , Estrogen Antagonists/therapeutic use , Tamoxifen/therapeutic use , Aged , Aromatase Inhibitors , Breast Neoplasms/metabolism , Breast Neoplasms/mortality , Disease-Free Survival , Drug Resistance , Female , Humans , Italy , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Postmenopause , Receptors, Estrogen/metabolism , Survival Rate
14.
Pharm Res ; 18(5): 600-7, 2001 May.
Article in English | MEDLINE | ID: mdl-11465414

ABSTRACT

PURPOSE: To synthesize new naproxen (01) derivatives with amide or ester structures or with a combination of the two (02-15). To compare their physicochemical properties with naproxen esters (16-22) and their respective skin permeation behavior. To study structure-permeation relationships via partial least squares (PLS)-analysis. METHODS: Stability, aqueous, and octanol solubility were determined. Lipophilicity and further 53 chemical descriptors were computed. A suitable in-vitro skin permeation model was developed to compare maximal flux (Jmax) of derivatives. Based on these flux data, PLS-analysis was performed to derive structure-permeation relationships. RESULTS: None of the new derivatives showed an improved flux in comparison to naproxen. This result can be explained by PLS-analysis: skin permeation increases with the solubility both in water and in octanol. For a good permeation, an optimized molecule should exhibit a small volume with a spherical shape. The surface area should be large in relation to volume, as indicated by the rugosity parameter. A clear separation between the hydrophobic and the hydrophilic domain (= high amphiphilic moment) is favorable. Lipophilicity is inversely correlated with skin permeation. CONCLUSIONS: PLS-analysis is a valuable tool to derive significant, internally predictive quantitative models for structure-permeation relationships of naproxen derivatives in the above described skin permeation assay.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Naproxen/pharmacokinetics , Skin Absorption , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Chemical Phenomena , Chemistry, Physical , Chromatography, Thin Layer , Diffusion , Female , Indicators and Reagents , Mass Spectrometry , Mice , Mice, Nude , Naproxen/administration & dosage , Naproxen/analogs & derivatives , Solubility , Spectrophotometry, Infrared , Spectroscopy, Fourier Transform Infrared
15.
J Comput Aided Mol Des ; 15(3): 203-17, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11289075

ABSTRACT

Antiviral quinolones are promising compounds in the search for new therapeutically effective agents for the treatment of AIDS. To rationalize the SAR for this new interesting class of anti-HIV derivatives, we performed a 3D-QSAR study on a library of 101 6-fluoro and 6-desfluoroquinolones, taken either from the literature or synthesized by us. The chemometric procedure involved a fully semiempirical minimization of the molecular structures by the AMSOL program, which takes into account the solvatation effect, and their 3D characterization by the VolSurf/GRID program. The QSAR analysis, based on PCA and PLS methods, shows the key structural features responsible for the antiviral activity.


Subject(s)
Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , HIV/drug effects , Quinolones/chemistry , Quinolones/pharmacology , Computer-Aided Design , Databases, Factual , Drug Design , HIV Infections/drug therapy , Humans , Models, Chemical , Multivariate Analysis , Quantitative Structure-Activity Relationship , Software
16.
Anticancer Res ; 21(1A): 307-12, 2001.
Article in English | MEDLINE | ID: mdl-11299753

ABSTRACT

The aim of this study was to explore, in a murine tumor, if the effectiveness of radiation, in doses and schedules commonly used in clinical practice is potentiated by the combined use of the recently developed drug gemcitabine. Gemcitabine (30-360 mg/kg b.w.) was administered i.p. in female C3D2F1 mice bearing a mammary adenocarcinoma alone or combined with X-rays. Firstly, gemcitabine (single administration) was administered alone or at 20 min, 4 h, and 24 h before X-ray treatments. The significant effect observed only at 24 h time interval, depended on the X-ray dose and not on the gemcitabine dose. Secondly, 4 gemcitabine administrations every 3 days were used in fractionated combined schedules (overall treatment time of 10 days). We studied the relationship among different doses of gemcitabine, alone or combined with 10 daily X-ray treatments (2 Gy/fraction). We observed an interactive effect of gemcitabine up to its threshold dose of 60 mg/kg/fraction. Furthermore, 10 X-ray daily treatments and 4 X-ray treatments every 3 days (total doses 20-40 Gy) were performed with gemcitabine 60 mg/kg/fraction to study the effect of different doses and schedules of X-rays. Tumor growth delays increase with higher X-ray doses, and this occurs more with 4 X-ray treatments than with 10 X-ray treatments. Our results re-affirm the uselessness of high gemcitabine doses, and indicate the effectiveness of combined gemcitabine-radiation fractionated protocols.


Subject(s)
Antimetabolites, Antineoplastic/administration & dosage , Carcinoma/drug therapy , Carcinoma/radiotherapy , Deoxycytidine/administration & dosage , Mammary Neoplasms, Experimental/drug therapy , Mammary Neoplasms, Experimental/radiotherapy , Radiation-Sensitizing Agents/administration & dosage , Animals , Antimetabolites, Antineoplastic/therapeutic use , Combined Modality Therapy , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Dose Fractionation, Radiation , Dose-Response Relationship, Radiation , Drug Administration Schedule , Female , Mice , Radiation-Sensitizing Agents/therapeutic use , Radiography , Skin/diagnostic imaging , Skin/drug effects , Gemcitabine
17.
Eur J Pharm Sci ; 11 Suppl 2: S29-39, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11033425

ABSTRACT

A method for the modeling and prediction of pharmacokinetic properties based on computed molecular interaction fields and multivariate statistics has been investigated in different experimental datasets. The program VolSurf was used to correlate 3D molecular structures with physico-chemical and pharmacokinetic properties. In membrane partitioning, VolSurf produced a two-component model explaining 94% of the total variation with a predictive q(2) of 0.90. This result was achieved without conformational sampling and without any quantum-chemical calculation. For the prediction of blood-brain barrier penetration the VolSurf model was able to predict the BBB profile for most of the drugs in the external prediction set. In Caco-2 and MDCK permeation experiments, VolSurf was used with success to establish statistical models and to predict the behaviour of new compounds. The method thus appears as a valuable new property filter in virtual screening and as a novel tool in optimizing the pharmacokinetic profile of pharmaceutically relevant compounds.


Subject(s)
Blood-Brain Barrier/physiology , Lead/pharmacokinetics , Models, Chemical , Models, Molecular , Animals , Blood-Brain Barrier/drug effects , Caco-2 Cells , Computer-Aided Design , Humans , Molecular Structure , Software
18.
J Med Chem ; 43(17): 3233-43, 2000 Aug 24.
Article in English | MEDLINE | ID: mdl-10966742

ABSTRACT

Traditional methods for performing 3D-QSAR rely upon an alignment step that is often time-consuming and can introduce user bias, the resultant model being dependent upon and sensitive to the alignment used. There are several methods which overcome this problem, but in general the necessary transformations prevent a simple interpretation of the resultant models in the original descriptor space (i.e. 3D molecular coordinates). Here we present a novel class of molecular descriptors which we have termed GRid-INdependent Descriptors (GRIND). They are derived in such a way as to be highly relevant for describing biological properties of compounds while being alignment-independent, chemically interpretable, and easy to compute. GRIND are obtained starting from a set of molecular interaction fields, computed by the program GRID or by other programs. The procedure for computing the descriptors involves a first step, in which the fields are simplified, and a second step, in which the results are encoded into alignment-independent variables using a particular type of autocorrelation transform. The molecular descriptors so obtained can be used to obtain graphical diagrams called "correlograms" and can be used in different chemometric analyses, such as principal component analysis or partial least-squares. An important feature of GRIND is that, with the use of appropriate software, the original descriptors (molecular interaction fields) can be regenerated from the autocorrelation transform and, thus, the results of the analysis represented graphically, together with the original molecular structures, in 3D plots. In this respect, the article introduces the program ALMOND, a software package developed in our group for the computation, analysis, and interpretation of GRIND. The use of the methodology is illustrated using some examples from the field of 3D-QSAR. Highly predictive and interpretable models are obtained showing the promising potential of the novel descriptors in drug design.


Subject(s)
Models, Molecular , Software , Butyrophenones/chemistry , Enzyme Inhibitors/chemistry , Glucose/analogs & derivatives , Glucose/chemistry , Phosphorylases/chemistry , Protein Binding , Receptor, Serotonin, 5-HT2A , Receptors, Serotonin/chemistry , Steroids/chemistry , Transcortin/chemistry
19.
J Cancer Res Clin Oncol ; 126(8): 461-7, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10961389

ABSTRACT

Increased interest in combining drugs with different targets has emerged over recent years. Our study aims at evaluating the effectiveness of combined gemcitabine/paclitaxel treatment taking into consideration doses, schedules, and toxicity. A spontaneous mammary carcinoma was transplanted into the right-hind foot of C3D2F1 mice. Paclitaxel (in doses from 20 to 80 mg/kg b.w.) and gemcitabine (in doses from 30 to 480 mg/kg b.w.) were administered i.p. in single or fractionated treatments. Toxicity and tumor growth delay (TGD) were the endpoints. TGDs for different gemcitabine doses in single administration (120, 240, and 360 mg/kg) overlapped (TGD approximately = 2.5 days). Toxicity was very high in daily administration. Results with gemcitabine alone showed the efficacy of treatments every 3 days. TGDs in fractionated treatments of 60 and 120 mg/kg x 4 were of approximately equals 16 days. Also in this case, tumor growth curves overlapped pointing out the uselessness of the high drug doses. For combined treatments, we used only fractionated protocols, administering gemcitabine every 3 days. Paclitaxel was administered alone in one or two fractions and with different sequences in respect to gemcitabine administration. With 120 mg/kg of gemcitabine all the protocols showed an increased unacceptable toxicity. The best result was obtained administering paclitaxel 40 mg/kg on days 1 and 15 and gemcitabine 60 mg/kg on days 3, 6, 9, and 12 (TGD = 38.2 days). The light toxicity and the high efficacy obtained with this protocol indicate the possible use of gemcitabine/paclitaxel treatment in clinical practice.


Subject(s)
Adenocarcinoma/drug therapy , Antimetabolites, Antineoplastic/toxicity , Antineoplastic Agents, Phytogenic/toxicity , Antineoplastic Combined Chemotherapy Protocols/toxicity , Deoxycytidine/analogs & derivatives , Mammary Neoplasms, Experimental/drug therapy , Paclitaxel/toxicity , Analysis of Variance , Animals , Antimetabolites, Antineoplastic/therapeutic use , Antineoplastic Agents, Phytogenic/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Division/drug effects , Deoxycytidine/therapeutic use , Deoxycytidine/toxicity , Dose-Response Relationship, Drug , Female , Mice , Mice, Inbred Strains , Paclitaxel/therapeutic use , Statistics, Nonparametric , Gemcitabine
20.
J Med Chem ; 43(16): 3033-44, 2000 Aug 10.
Article in English | MEDLINE | ID: mdl-10956211

ABSTRACT

We present a computational procedure aimed at understanding enzyme selectivity and guiding the design of drugs with respect to selectivity. It starts from a set of 3D structures of the target proteins characterized by the program GRID. In the multivariate description proposed, the variables are organized and scaled in a different way than previously published methodologies. Then, consensus principal component analysis (CPCA) is used to analyze the GRID descriptors, allowing the straightforward identification of possible modifications in the ligand to improve its selectivity toward a chosen target. As an important new feature the computational method is able to work with more than two target proteins and with several 3D structures for each protein. Additionally, the use of a 'cutout tool' allows to focus on the important regions around the active site. The method is validated for a total number of nine structures of the three homologous serine proteases thrombin, trypsin, and factor Xa. The regions identified by the method as being important for selectivity are in excellent agreement with available experimental data and inhibitor structure-activity relationships.


Subject(s)
Drug Design , Ligands , Algorithms , Binding Sites , Factor Xa/chemistry , Factor Xa/metabolism , Models, Molecular , Structure-Activity Relationship , Thrombin/chemistry , Thrombin/metabolism , Trypsin/chemistry , Trypsin/metabolism
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