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A Retico

Publications and source records attributed to A Retico.

14 recordsLinked to original sources
PubMed2006

A completely automated CAD system for mass detection in a large mammographic database.

Mass localization plays a crucial role in computer-aided detection (CAD) systems for the classification of suspicious regions in mammograms. In this article we present a completely automated classification system for the detection of masses in digitized mammographic images. The tool system we discuss consists in three processing levels: (a) Image segmentation for the localization of regions of interest (ROIs). This step relies on an iterative dynamical threshold algorithm able to select iso-intensity closed contours around gray level maxima of the mammogram. (b) ROI characterization by means of textural features computed from the gray tone spatial dependence matrix (GTSDM), containing second-order spatial statistics information on the pixel gray level intensity. As the images under study were recorded in different centers and with different machine settings, eight GTSDM features were selected so as to be invariant under monotonic transformation. In this way, the images do not need to be normalized, as the adopted features depend on the texture only, rather than on the gray tone levels, too. (c) ROI classification by means of a neural network, with supervision provided by the radiologist's diagnosis. The CAD system was evaluated on a large database of 3369 mammographic images [2307 negative, 1062 pathological (or positive), containing at least one confirmed mass, as diagnosed by an expert radiologist]. To assess the performance of the system, receiver operating characteristic (ROC) and free-response ROC analysis were employed. The area under the ROC curve was found to be Az = 0.783 +/- 0.008 for the ROI-based classification. When evaluating the accuracy of the CAD against the radiologist-drawn boundaries, 4.23 false positives per image are found at 80% of mass sensitivity.

Algorithms↗
PubMed2005

GPCALMA: a Grid-based tool for mammographic screening.

OBJECTIVES: The next generation of high energy physics (HEP) experiments requires a GRID approach to a distributed computing system: the key concept is the Virtual ORGANISATION (VO), a group of distributed users with a common goal and the will to share their resources. METHODS: A similar approach, applied to a group of hospitals that joined the GPCALMA project (Grid Platform for Computer Assisted Library for MAmmography), will allow common screening programs for early diagnosis of breast and, in the future, lung cancer. The application code makes use of neural networks for the image analysis and is useful in improving the radiologists' diagnostic performance. GRID services allow remote image analysis and interactive online diagnosis, with a potential for a relevant reduction of the delays presently associated with screening programs. RESULTS AND CONCLUSIONS: A prototype of the system, based on AliEn GRID Services [1], is already available, with a central server running common services [2] and several clients connecting to it. Mammograms can be acquired in any location; the related information required to select and access them at any time is stored in a common service called Data Catalogue, which can be queried by any client. Thanks to the PROOF facility [3], the result of a query can be used as input for analysis algorithms, which are executed on the nodes where the input images are stored,. The selected approach avoids data transfers for all the images with a negative diagnosis and allows an almost real time diagnosis for the set of images with high cancer probability.

Algorithms↗
PubMed1995

Antifungal agents. 9. 3-Aryl-4-[alpha-(1H-imidazol-1-yl)arylmethyl]pyrroles: a new class of potent anti-Candida agents.

A new class of potent antifungal agents, namely, 3-aryl-4-[alpha-(1H-imidazol-1-yl)arylmethyl]-pyrroles, is described. These compounds are related to bifonazole and pyrrolnitrin, two compounds belonging to the class of antimycotic drugs. The synthesis of the title pyrroles has been performed starting from 1,3-diaryl-2-propen-1-ones, which were reacted with tosylmethyl isocyanide to give 3-aroyl-4-arylpyrroles. Reduction of the resulting compounds by lithium aluminum hydride furnished the related alcohols, which were treated with 1,1'-carbonyldimidazole to afford the required imidazole derivatives. Forty-four new pyrroles which incorporate an (arylmethyl)imidazole moiety in the 3-arylpyrrole structure were prepared by the above procedure and tested in vitro against Candida albicans and Candida spp. Among test compounds, 10 were found to be highly active against C. albicans. The most active derivative (27) was twice as potent (MIC90) as bifonazole, and its activity was 4 times greater than those of miconazole and ketoconazole. The other nine compounds showed antifungal activity of the same order of that of bifonazole and were ca. 2 times as active as miconazole and ketoconazole. Derivatives 21 and 27 tested in vivo against C. albicans A170 were shown to be highly effective in rabbit skin candidosis. Pharmacological studies on compounds 27 and other related pyrroles (19, 35, 36, 38, 39, and 49) are in progress to select one of them as a potential candidate for clinical experiments.

Adult↗
PubMed1994

Antifungal agents. VIII. Synthesis and antifungal activities of bipyrryl analogues of bifonazole.

Various bipyrryl analogues of bifonazole were synthesized starting from aryl-3-pyrryl-1-imidazolylmethanes. The introduction of a second pyrryl portion was performed by linking an acrylate moiety at 1-position of the pyrrole ring and then by treatment with TosMIC. The bipyrryl esters were hydrolyzed and decarboxylated to afford the required imidazoles. All new imidazole derivatives were tested against Candida albicans and Candida spp using as standard controls miconazole, bifonazole and ketoconazole.

Antifungal Agents↗
PubMed1993

Antifungal agents, II: Synthesis and antifungal activities of aryl-1H-pyrrol-2-yl-1H-imidazol-1-yl-methane derivatives with unsaturated chains.

The synthesis and antifungal activities of aryl-1H-pyrrol-2-yl-1H-imidazol-1-yl-methanes having allyl, crotyl, and acrylate chains linked to the N-pyrrole atom and substituted at phenyl ring by Cl, F, CH3, and NO2 groups are reported. In vitro tests against Candida albicans and Candida spp. showed 2,4-dichlorophenyl-1-allyl-1H-pyrrol-2-yl-1H-imidazol-1-yl-methane to be the most potent derivative with activities comparable to those of ketoconazole and slightly inferior to those of bifonazole and miconazole. Some structure-activity relationships are discussed.

Antifungal Agents↗
PubMed1993

Antifungal agents. VI. In vitro antifungal activities of halobenzoyl esters of cis- and trans-[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1,3- dioxolan-4-yl]carbinols.

The synthesis and the in vitro antifungal activities against Candida albicans and Candida spp of a number of halobenzoyl esters of cis- and trans- [2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolan -4- yl]carbinols is reported. Some new imidazoles were found more active than ketoconazole and sometimes as potent as bifonazole against Candida albicans. All derivatives were found scarcely active against Candida spp.

Antifungal Agents↗
PubMed1993

Antifungal agents. III. Naphthyl and thienyl derivatives of 1H-imidazol-1-yl-4-phenyl-1H-pyrrol-3-ylmethane.

The in vitro antifungal activities of some naphthyl and thienyl derivatives of 1H-imidazol-1-yl-4-phenyl-1H-pyrrol-3-ylmethane against Candida albicans and Candida spp are reported. The title derivatives were prepared starting from proper arylstirylketones, which were reacted with tosylmethylisocyanide (Tos-MIC) to afford the related 4-phenyl-1H-pyrrol-3-yl aryl ketones. Reduction of ketones to the corresponding carbinols followed by treatment of the last compounds with 1,1'-carbonyldiimidazole (CDI) gave the title imidazoles. The related N-methylpyrrole derivatives are also described.

Antifungal Agents↗
PubMed1992

Researches on antibacterial and antifungal agents, XIV: Thiophene analogues of bifonazole.

Some thiophene analogues of bifonazole have been synthesized by standard procedures and their antifungal activity has been tested against Candida albicans. Among test derivatives biphenyl-4-yl-5-chloro-thien-2-ylimidazol-1-ylmethane and its 5-deschlorothien-2-yl analogue resulted to be the most active. Their antifungal potency was almost comparable to that of control substances, such as miconazole, ketoconazole, and bifonazole. Replacement of benzene by the pyrrole ring in the biphenyl portion retained almost quantitatively the antifungal activity, whereas substitution with other azoles and with nitrogen alicyclic rings led always to less potent derivatives.

Antifungal Agents↗
PubMed1990

Macrophage lysozyme stimulation by fructose-1-6-diphosphate.

FDP produces an increase of serum lysozyme concentration which may be related to stimulation of the phagocytic activity. Mice macrophages in vitro produce extracellular and intracellular LSZ (lysozyme) and FDP (fructose-1-6-diphosphate) increases this production. Also in vivo FDP stimulates the macrophages intracellular lysozyme production. The toxic activity in vitro and the protection in vivo against Staphylococcus pyogenes after FDP administration can also be related to macrophage stimulation.

Animals↗
PubMed1989

Action of the ketoconazole-alkylaminoethylglycine combination on Candida albicans.

High concentrations of ketoconazole (Ktc) exhibit poor antimicrobial activity in microbicidal test. Alkylaminoethylglycine (AAEG), an amphoteric surface-active agent, employed in subinhibitory concentrations, can enhance the action of ketoconazole. The Ktc-AAEG combination causes a higher rate of potassium ion release compared to both drugs separately. The increased ketoconazole activity may be ascribed to the membrane damage indicated by increased permeability to potassium ions.

Candida albicans↗
PubMed1988

Itraconazole activity against fungal germination.

Itraconazole was found to be superior to ketoconazole in its antifungal activity in vitro against Hyphomycetes and Candida. In particular, complete inhibition of germination of Candida albicans and Aspergillus spp. by a lower dose of itraconazole can explain the better activity in vivo of this drug.

Antifungal Agents↗
PubMed1981

[Effect of propyl gallate on the antibacterial activity of meclocycline sulfosalicylate].

Propyl gallate shows little antibacterial activity however it markedly potentiates the activity of meclocycline against Pseudomonas, Proteus, Serratia, Escherichia coli and Klebsiella strains. The potentiating effect of propyl gallate is seen especially with resistant strains whereas sensitive strains of Salmonella do not manifest a potentiating effect on meclocycline by propyl gallate. The mechanism of action of propyl gallate is discussed.

Bacteria↗