Search Results - (Author, Cooperation:R. Salazar)

2012-01-28

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Antibodies, Monoclonal/pharmacology ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents/pharmacology/therapeutic use ; Apoptosis/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cetuximab ; Colorectal Neoplasms/*drug therapy/*enzymology/genetics/pathology ; Drug Resistance, Neoplasm/*drug effects ; Drug Synergism ; Enzyme Activation/drug effects ; Erlotinib Hydrochloride ; Feedback, Physiological/*drug effects ; Female ; HEK293 Cells ; Humans ; Indoles/pharmacology/therapeutic use ; Melanoma/drug therapy/metabolism ; Mice ; Protein Kinase Inhibitors/pharmacology/therapeutic use ; Proto-Oncogene Proteins B-raf/*antagonists & ; inhibitors/chemistry/*genetics/metabolism ; Quinazolines/pharmacology/therapeutic use ; RNA Interference ; Receptor, Epidermal Growth Factor/*agonists/antagonists & inhibitors/metabolism ; Sulfonamides/pharmacology/therapeutic use ; Xenograft Model Antitumor Assays

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1434-6036

PACS. 05.20.-y Classical statistical mechanics - 05.20.Gg Classical ensemble theory - 02.70.Lq Monte Carlo and statistical methods 75.10.Hk Classical spin models

Springer Online Journal Archives 1860-2000

Physics

Abstract: We introduce a new nonextensive entropic measure that grows like , where N is the size of the system under consideration. This kind of nonextensivity arises in a natural way in some N-body systems endowed with long-range interactions described by interparticle potentials. The power law (weakly nonextensive) behavior exhibited by is intermediate between (1) the linear (extensive) regime characterizing the standard Boltzmann-Gibbs entropy and (2) the exponential law (strongly nonextensive) behavior associated with the Tsallis generalized q-entropies. The functional is parametrized by the real number in such a way that the standard logarithmic entropy is recovered when . We study the mathematical properties of the new entropy, showing that the basic requirements for a well behaved entropy functional are verified, i.e., possesses the usual properties of positivity, equiprobability, concavity and irreversibility and verifies Khinchin axioms except the one related to additivity since is nonextensive. For , the entropy becomes superadditive in the thermodynamic limit. The present formalism is illustrated by a numerical study of the thermodynamic scaling laws of a ferromagnetic Ising model with long-range interactions.

Electronic Resource

1432-1912

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

0030-4018

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

1432-1335

Springer Online Journal Archives 1860-2000

Medicine

Summary Comparative studies of the hydrolytic and transferring activity of the NAD(P)-Glycohydrolase were carried out using the microsomes of liver, spleen, brain and some implantable tumors (Yoshida-Sarkom, Walker-256-Carcinom, Jensen-Sarkom, DS-Carcinosarkom und Shay-Chloro-Leukom). The reaction rate of the enzyme was neither in the normal tissues nor in the tumors the same when based on the nitrogen content of the enzyme preparations. An increase of the activity of the NAD(P)-glycohydrolase occurred in the chemosensible Yoshida-sarcoma and Shay-Chloro-leukoma, but not in the chemoresistent DS-carcinosarcoma by pretreating the tumorbearing rats with Cyclophosphamide, with no alteration in the enzyme activity of the normal tissue. Moreover the microsomes of the chemosensible tumors in Cyclophosphamide-treated rats form more NAD(P)-analogues than in the untreated animals. Normal tissue, as well as the chemoresistent DS-carcinosarcoma synthetize, when treated with Cyclophosphamide, no more 3-APAD(P) than without cytostatic treatment. After injection of 6-AN formation of 6-AN-analogues of NAD(P) occurs in all tissues and tumors under investigation. Pretreatment with Cyclophosphamide enhances the content of the abnormally structured pyridine nucleotides alone in the tumor more than twice. In view of these experimental findings an increase of the “lethal synthesis” in tumor cells ought to be possible in principle without influencing the normal tissues.

Zusammenfassung In vergleichenden Untersuchungen werden die hydrolytische und transferierende Aktivität der NAD(P)-Glykohydrolase in Mikrosomen aus Leber, Milz und Gehirn und einigen Impftumoren (Jensen-, Walker-, Yoshida-, DS-Carcinosarkom und Shay-Chloro-Leukom) gemessen. Bezogen auf den N-Gehalt der Enzympräparate ist die Reaktionsgeschwindigkeit des Fermentes weder in den normalen Geweben noch in den Tumoren gleich. Durch Vorbehandlung der tumortragenden Ratten mit Cyclophosphamid erhöht sich die Aktivität der NAD(P)-Glykohydrolase des chemosensiblen Yoshida-Sarkoms und Shay-Chloro-Leukoms, aber nicht im chemoresistenten DS-Carcinosarkom. In den Normalgeweben blieb die Aktivität des Fermentes stets unverändert. Die Mikrosomen aus chemosensiblen Tumoren endoxanbehandelter Ratten bilden in vitro auch mehr NAD(P)-Analoge als die aus den normalen Organen oder aus dem therapieresistenten DS-Carcinosarkom oder aus den Tumoren unbehandelter Tiere. Nach Injektion von 6-AN lassen sich in allen untersuchten Geweben und Tumoren 6-AN-Analoge des NAD(P) nachweisen. Durch Vorbehandlung mit Endoxan steigt der Gehalt an diesen falsch strukturierten Pyridinnucleotiden spezifisch im Tumor um mehr als das Doppelte an. Auf Grund dieser Versuchsergebnisse müßte es prinzipiell möglich sein, die Synthese letaler Mengen falsch strukturierter Pyridinnucleotide in Tumorzellen zu erzielen, ohne daß dadurch das normale Gewebe beeinflußt wird.

Electronic Resource

1573-4846

phase diagram ; aerogels ; Monte-Carlo simulations ; phase transitions ; surface interaction ; confinement effects

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract It is found experimentally that the coexistence region of a vapor-liquid system or a binary mixture is substantially narrowed when the fluid is confined in an aerogel with a high degree of porosity (e.g., of the order of 95 to 99%). A Hamiltonian model for this system has recently been introduced [1]. We have performed Monte-Carlo simulations for this model to obtain the phase diagram for the model. We use a periodic fractal structure constructed by diffusion-limited cluster-cluster aggregation (DLCA) method to simulate a realistic gel environment. The phase diagram obtained is qualitatively similar to that observed experimentally. We also have observed some metastable branches in the phase diagram which have not been seen in experiments yet. These branches, however, might be important in the context of recent theoretical predictions and other simulations.

Electronic Resource

1619-6937

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Zusammenfassung Eine optische Methode wird beschrieben, die es ermöglicht, die örtlich, zeitlich veränderliche Dicke eines Rieselfilmes zu messen. Messungen dieser Art wurden an mehreren Stellen entlang der Strömungsrichtung für Reynoldszahlen von 145 bis 4030 durchgeführt. Die erhaltenen Meßwerte wurden auf folgende statistische Eigenschaften hin untersucht: Frequenzspektrum, Wahrscheinlichkeitsdichte und Wellengeschwindigkeit. Die gewonnenen Resultate wurden, wenn möglich, mit bekannten, jedoch auf andere Weise ermittelten Ergebnissen verglichen. Es zeigte sich, daß für die Länge des untersuchten Rieselfilmes von 134 cm die Filmeigenschaften stark vom Abstand der Meßstelle zum Beginn des Rieselfilmes abhängen. Diese Abhängigkeit wird schwächer nach einer Übergangszone, in der sich die Wellenbewegung zu stabilisieren scheint. Zumindest drei Bereiche von Reynoldszahlen existieren, die sich durch unterschiedliche statistische Eigenschaften des Rieselfilmes auszeichnen. Das wird besonders bei einem Vergleich der Kurven der Wahrscheinlichkeitsdichten deutlich.

Summary An optical method for measuring time varying local film thickness is briefly described. Recordings of film thickness were made for Reynolds numbers (equal to 4Q/v) from 145 to 4030 at varying distances along the direction of the flow. These recordings were digitized and analyzed by digital computer for the following statistical parameters: a) frequency spectrum, b) probability density and c) wave velocity. Where possible these results are compared with those obtained by different thickness measurement methods and recorded at different locations relative to the entrance to the flow. For the length of flow used here, 134 cm, surface characteristics are strongly dependent on distance from the entrance. This dependence appears to lessen after a transition zone where the wave motion stabilizes. There are at least three Reynolds number regions within which the surface characteristics are quite distinct, wavy laminar, transitional and turbulent. These differences are shown by changes in probability density curves from one region to another.

Electronic Resource

1573-4986

glycation ; fructosyllysine ; receptor ; cellular myosin heavy chain ; nucleolin

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Amadori-modified proteins are bound by macrophages and monocytes via fructosyllysine-specific receptors. Detergent extracts from U937 cell membranes were used to purify the binding proteins by affinity purification on glycated polylysine coated magnetic beads followed by SDS-PAGE. Two proteins of 200 and 100[emsp4 ]kDa were isolated. MS-analysis of the 200[emsp4 ]kDa protein showed high homologies with cellular myosin heavy chain, type A. Both fructosyllysine specific binding proteins, cellular myosin heavy chain and nucleolin, are glycosylated.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract Twenty-six patients with hematological or solid tumors who developed bacteremia caused byStenotrophomonas maltophilia (n=10),Pseudomonas putida (n=6),Sphingomonas paucimobilis complex (n=4) orAlcaligenes xylosoxidans (n=6) in the period between 1993 and 1995 were studied. Seventeen patients were neutropenic during the infection, and 13 were undergoing bone marrow or peripheral blood stem cell transplantation. Twenty-three patients had catheter-related infections; only 3 of the 26 patients developed septic complications (all due toStenotrophomonas maltophilia). Twenty patients were cured following catheter removal, either as primary measure (n=8) or salvage measure (n=12). Four responded to antibiotic therapy only, and two died of septic complications. Such infections in hematological and oncological patients have increased in this hospital from no cases in 1975 to 11 cases in 1995.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract  The clinical characteristics and outcome of bacteraemia caused by non-glucose-fermenting gram-negative bacilli and Aeromonas spp. were examined in 115 adults with haematological malignancies or solid tumours. The most aggressive pathogens were Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Aeromonas spp., Acinetobacter spp. and Burkholderia cepacia, all of which caused either septic syndrome or pneumonia in more than 40% of cases. Pseudomonas aeruginosa was involved less often in catheter-related bacteraemia than other species. Polymicrobial bacteraemia (n=28) was more often catheter-related than monomicrobial bacteraemia and more often required catheter removal for definitive cure. The most important predictors of catheter-related bacteraemia and its outcome were polymicrobial infection, the presence of pneumonia or septic syndrome and the species involved.

Electronic Resource

1572-9680

multipurpose trees ; assessment methodology ; standardization ; height ; diameter ; biomass

Springer Online Journal Archives 1860-2000

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract There is an urgent need to standardize the methods used to assess the growth of multipurpose trees. Most of the standard methods so far described have been developed specifically for use in multilocational trial networks. This paper was prepared for the F/FRED/ICRAF Workshop on MPTS Assessment Methods, held in Thailand in May 1991 to develop internationally-recognised standards for assessment methodology. It critically reviews the methods prescribed by different networks for height and diameter measurement, and for biomass estimation, giving researchers a range of methodological options to consider and re-emphasizing the need, all too often neglected, to define assessment methods clearly and unambiguously.

Electronic Resource

1572-9540

Springer Online Journal Archives 1860-2000

Physics

Abstract A large number of ceramic sherds from Chavin, Peru, as well as recent clay samples from the same region have been studied by Mössbauer spectroscopy. The changes of the Mössbauer spectra of the clay were studied as a function of firing temperature and atmosphere. From a comparison of these data with those form the sherds one can make estimates of the precolumbian firing conditions.

Electronic Resource

1572-9540

Springer Online Journal Archives 1860-2000

Physics

Abstract To obtain information on the firing of inca ceramics, 7 samples from different locations were studied by Mössbauer spectroscopy including a detailed laboratory refiring procedure. The glaze typical for the surface of this ware was studied by Mössbauer scattering.

Electronic Resource

1572-9540

Springer Online Journal Archives 1860-2000

Physics

Abstract An illite separated from mylonites from the southern rim of the Bohemian massif was studied by Mössbauer spectroscopy at temperatures between 300 and 1.8 K. The iron is mainly contained in oxides associated with the illite. Only 13% of the iron are structural Fe3+ and Fe2+ within the clay mineral matrix. The transformations of the oxidic iron during heating at temperatures up to 1250°C were followed by Mössbauer measurements at 300 and 4.2 K.

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