Felix Duque | Universidad Autónoma de Madrid (original) (raw)
Papers by Felix Duque
International Archives of Allergy and Immunology, 1984
Sera of 6 patients with Chediak-Higashi syndrome and sera of their mothers were studied for heter... more Sera of 6 patients with Chediak-Higashi syndrome and sera of their mothers were studied for heterophile antibodies. Sera of 5 patients as well as 5 sera of their mothers contained antibodies against trypsinized bovine erythrocytes, tissue sediments of guinea pig kidney or high molecular weight glycoprotein (HMWGP) of bovine erythrocyte stromata. The antibodies combining with HMWGP in enzyme immunoassay belonged to IgM and IgG classes. Although none of the sera had significant titer of agglutinins against sheep erythrocytes, on the basis of absorption and inhibition studies, these antibodies seemed to belong to the Hanganutziu-Deicher group of antibodies.
Page 1. 350 REVISTA COLOMBIANA DE REUMATOLOGÍA MARIO ANDRÉS QUINTANA DUQUE & Cols. REVISTA CO... more Page 1. 350 REVISTA COLOMBIANA DE REUMATOLOGÍA MARIO ANDRÉS QUINTANA DUQUE & Cols. REVISTA COLOMBIANA DE REUMATOLOGÍA VOL. 12 No. 4, Diciembre 2005, pp. 350-361 © 2005, Asociación Colombiana de Reumatología 1. Médico interno. ...
... Enrique Toro1*, Mario Andrés Quintana Duque2*, José Félix Restrepo3, Gerardo Quintana4, Feder... more ... Enrique Toro1*, Mario Andrés Quintana Duque2*, José Félix Restrepo3, Gerardo Quintana4, Federico Rondón5, Álvaro Sánchez5, Fidencio Cons Molina6, Antonio Iglesias Gamarra7 ... a partir de la casuística obteni-da especialmente en el Hospital San Juan de Dios ...
Biochemical Systematics and Ecology, 2001
The volatile constituents of the marine sponge Ircinia felix were obtained by dynamic headspace e... more The volatile constituents of the marine sponge Ircinia felix were obtained by dynamic headspace extraction and analyzed by HRGC, HRGC-MS and HRGC-Odor at sniffing port. Fifty-nine volatiles were identified for the first time in the odor of this sponge. Hydrocarbons (32.9%), alcohols (17.8%) and carbonyl compounds (16.0%) predominated in the sponge volatile profile, followed by esters (11.6%), halogen compounds (8.6%), ethers (7.7%), nitrogen and/or sulfur compounds (4.6%) and carboxylic acids (0.8%). Among the identified volatiles, thiobismethane (commonly known as dimethylsulfide), methyl isocyanide and methyl isothiocyanate were found to be responsible for the nauseating and toxic smell emitted by the sponge and for the antimicrobial activity detected in the volatile extract. Exudation experiments in aquarium and in situ conditions revealed that thiobismethane, methyl isocyanide and methyl isothiocyanate are continuously released by the sponge. Upon injury, the concentration of these volatiles increased strongly. Hence, these substances form a chemical protective barrier which may help these sponges avoid fouling, compete for space, prevent infection in the short term, and/or signal generalist predators regarding the existence of other toxic substances in the internal tissues. # : S 0 3 0 5 -1 9 7 8 ( 0 0 ) 0 0 0 8 1 -8
... VOL. 14 No. 4 - 2007 Figura 7. Púrpura periorbitaria en amiloidosis. Figura 8. Lesiones lític... more ... VOL. 14 No. 4 - 2007 Figura 7. Púrpura periorbitaria en amiloidosis. Figura 8. Lesiones líticas en el radio y en el carpo por depósitos amiloideos en un paciente con mieloma múltiple. Figura 9. Compromiso cutáneo en tórax de pa-ciente con síndrome POEMS. ...
Biodiversity and Conservation, 2007
The genetic diversity of 76 accessions of lima bean (Phaseolus lunatus L.), collected mostly from... more The genetic diversity of 76 accessions of lima bean (Phaseolus lunatus L.), collected mostly from home gardens, was assessed with AFLPs and seed descriptors to evaluate the potential for recovering a lost ex situ collection in Cuba. The sample contained 60 accessions collected from 25 home gardens in the three main geographical regions of Cuba and represented the three cultivated types found on the island. Four more accessions were part of the former ex situ collection and the remaining 12 accessions were selected from the world bean collection held at the International Center for Tropical Agriculture. Some morphological measurements discriminated among cultivated types. The analysis of 62 polymorphic bands obtained with two AFLP primer combinations indicated that the three cultivated bean types were comparable in terms of molecular diversity and that no pattern of variation was associated with geographical distribution. However, a multiple correspondence analysis with the same molecular data detected different genetic groups. Three of these groups included all the cultivated accessions collected from home gardens, but could not be explained by the seed descriptors. The results therefore suggest that a scientifically sound collecting strategy to recover the former Cuban ex situ gene bank should consider combining geographical, morphological, and molecular data. The findings also suggest that any proposed methodologies should be considered before developing a conservation strategy based on an ex situ or combined ex situ and in situ approaches.
Crop Science, 2005
... Félix Alberto Guzmán a ,; Helmer Ayala b ,; César Azurdia b ,; Myriam Cristina Duque c and; M... more ... Félix Alberto Guzmán a ,; Helmer Ayala b ,; César Azurdia b ,; Myriam Cristina Duque c and; M. Carmen de Vicente * a. a International Plant Genetic Resources ... H4, C, C. annuum, Bap-ik, S.Juan Chamelco, A. Verapaz, 1300. ... H25, A, C. annuum, Pico de Gallina, Chisec, A. Verapaz ...
Revista De Saude Publica, 2004
Realizaram-se bioensaios para detectar a susceptibilidade de Aedes aegypti aos inseticidas químic... more Realizaram-se bioensaios para detectar a susceptibilidade de Aedes aegypti aos inseticidas químicos, temefós e cipermetrina. Os resultados mostraram que esta espécie é suscetível a temefós e apresenta resistência a cipermetrinae.
Journal of Neuroscience Research, 2009
An experimental model based on kainic acid (KA) injections replicates many phenomenological featu... more An experimental model based on kainic acid (KA) injections replicates many phenomenological features of human temporal lobe epilepsy, the most common type of epilepsy in adults. Taurine, 2-aminoethanesulfonic acid, present in high concentrations in many invertebrate and vertebrate systems, is believed to serve several important biological functions. In addition, it is believed to have a neuroprotective role against several diseases. In the present study, an experimental mouse model based on taurine pretreatment prior to KA administration has been improved to study whether taurine has a neuroprotective effect against KA-induced behavior and cell damage. Under different treatments tested, taurine's most neuroprotective effects were observed with intraperitoneal taurine injection (150 mg/kg dosage) 12 hr before KA administration. Thus, a reduction in or total absence of seizures, together with a reduction in or even disappearance of cellular and molecular KA-derived effects, was detected in mice pretreated with taurine compared with those treated only with KA. Moreover, the use of tritiated taurine revealed taurine entry into the brain, suggesting possible changes in intracellular:extracellular taurine ratios and the triggering of pathways related to neuroprotective effects. © 2008 Wiley-Liss, Inc.
Natural Product Letters, 1995
Abstract The configuration at C-18 of variabilin (1), isolated from a Caribbean sponge, Ircinia f... more Abstract The configuration at C-18 of variabilin (1), isolated from a Caribbean sponge, Ircinia felix, was established to be R. Variabilin acetate (2) was oxidatively degraded and converted into di-(R)-MTPA ester of 2-methylheptane-1, 6-diol, which was found to have 2 R-...
Biodegradation, 2010
Agaricus brasiliensis CS1, Pleurotus ostreatus H1 and Aspergillus flavus produced holocellulases ... more Agaricus brasiliensis CS1, Pleurotus ostreatus H1 and Aspergillus flavus produced holocellulases when grown in solid and submerged liquid cultures containing agro-industrial residues, including sugar cane bagasse and dirty cotton residue, as substrates. These isolates proved to be efficient producers of holocellulases under the conditions used in this screening. Bromatological analysis of agro-industrial residues showed differences in protein, fiber, hemicellulose, cellulose and lignin content. Maximal holocellulase activity (hemicellulase, cellulase and pectinase) was obtained using solid-state cultivation with 10% substrate concentration. In this case, remarkably high levels of xylanase and polygalacturonase activity (4,008 and 4,548 IU/l, respectively) were produced by A. flavus when grown in media containing corn residue, followed by P. ostreatus H1 with IU/l values of 1,900 and 3,965 when cultivated on 5% and 10% sugar cane bagasse, respectively. A. brasiliensis CS1 showed the highest reducing sugar yield (11.640 mg/ml) when grown on medium containing sugar cane bagasse. A. brasiliensis was also the most efficient producer of protein, except when cultivated on dirty cotton residue, which induced maximal production in A. flavus. Comparison of enzymatic hydrolysis of sugar cane bagasse and dirty cotton residue by crude extracts of A. brasiliensis CS1, P. ostreatus H1 and A. flavus showed that the best reducing sugar yield was achieved using sugar cane bagasse as a substrate.
We outline here some of the steps we are taking towards the development of reliable tools for qua... more We outline here some of the steps we are taking towards the development of reliable tools for quantitative predictions of thermodynamic properties of complex fluids with equations based on statistical mechanics. The long term objective is to provide a userfriendly computer code and a wide database of molecular parameters for different compounds, able to be implemented in a process simulator. We have observed that the keys of the success when using molecular modelling tools for predictions rely on the selection of the appropriate model, representative of the molecular structure, and the use of physically meaningful molecular parameters.
Alles ist sie mit einem male" La actitud de Goethe en la naturaleza 1 Menschliches allzzl Menschl... more Alles ist sie mit einem male" La actitud de Goethe en la naturaleza 1 Menschliches allzzl Menschlzches, II, Der Wanderer und sem Schatten, 125. (Kritzsche Stud~enazisgabe 2, 607): "Nur für wenige hat er gelebt und lebt er noch: fur die Meisten 1st er Nichts, als eine Fanfare der Eitelkeit, welche man von Zeit zu Zeit über die deutsche Granze hinüberblast. Goethe, nicht nur ein guter und grosser Mensch, sondern eine Cultur, Goethe ist in der Geschichte der Deutschen ein Zwischenfall ohne Folgen."
Lipids, 1997
The methanolic extract of the marine sponge Ircinia felix has yielded nine novel fatty acid ester... more The methanolic extract of the marine sponge Ircinia felix has yielded nine novel fatty acid esters, (7E, 12E, 18R, 20Z)-variabilin (5Z, 9Z)-22-methyltricosadienoate, (7E, 12E, 18R, 20Z)-variabilin (5Z, 9Z)-tetracosadienoate, (7E, 12E, 18R, 20Z)-variabilin hexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 10-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 15-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 14-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 9-octadecenoate, (7E, 12E, 18R, 20Z)-variabilin octadecanoate, and (7E, 12E, 18R, 20Z)-variabilin 2,11-dimethyloctadecanoate, along with the recently described (7E, 12E, 18R, 20Z)-variabilin 11-methyloctadecanoate. The characterization of the new fatty acids (5Z, 9Z)-22-methyltricosadienoic and 2,11-dimethyloctadecanoic acids is also described. The chemical structures were determined by extensive spectroscopic, chromatographic, and chemical analyses.
Natural Product Letters, 1995
A methanol extract of the Caribbean sponge Ircinia felix afforded a mixture of fatty acid esters ... more A methanol extract of the Caribbean sponge Ircinia felix afforded a mixture of fatty acid esters of variabilin and its isomers. Among these the novel variabilin 11-methyloctadecanoate 1 was characterized on the basis of spectral, chromatographic and chemical evidence.
Theriogenology, 2004
The objective of this study was to determine the effect of a sustained propylene glycol administr... more The objective of this study was to determine the effect of a sustained propylene glycol administration to recipients of frozen/thawed in vivo derived bovine embryos. Heifers were treated with oral propylene glycol for the last 20 days before embryo transfer (n ¼ 142), and untreated as controls (n ¼ 133). Progesterone, insulin, insulin-like growth factor-I, glucose, urea and triglyceride were analysed in blood on Day 0 and Day 7 of the estrous cycle corresponding to embryo transfer. The heifers were selected as recipients when showing progesterone levels <2.0 ng/ml (Day 0) and >2.5 ng/ml (Day 7), according to corpus luteum quality on Day 7 by technicians unaware of animals treated.
Annals of Thoracic Surgery, 2000
http://ats.ctsnetjournals.org/cgi/content/full/70/1/258 on the World Wide Web at:
Atrial tachycardias are the most common cardiac arrhythmias in clinical practice, which induce ch... more Atrial tachycardias are the most common cardiac arrhythmias in clinical practice, which induce changes in atrial properties that help to perpetuate them. These changes are called "atrial remodeling". Recent studies have shown that rapid ectopic activity principally on the pulmonary veins can trigger reentrant mechanisms and lead to atrial tachycardias. However, the influences of ectopic foci location, the number of ectopic beats and its frequency on the likelihood of triggering reentries are not well known. In this work the effects of electrical remodeling were incorporated in an atrial cell model and integrated in a three-dimensional model of human atria, to develop a study of vulnerability for reentries. To carry out the study, an ectopic beat and a burst of six ectopic beats at two different frequencies were applied in six different locations in the atria. The results show greater vulnerability in the left pulmonary veins when we applied a single ectopic beat. When we increase the number of ectopic beats to six, a greater width of the vulnerable window was observed when ectopic focus frequency was high. The location, the number of ectopic beats and their frequency affect the vulnerability for reentry.
Applied and Environmental Microbiology, 2006
Pseudomonas putida KT2440, a saprophytic soil bacterium that colonizes the plant root, is a suita... more Pseudomonas putida KT2440, a saprophytic soil bacterium that colonizes the plant root, is a suitable microorganism for the removal of pollutants and a stable host for foreign genes used in biotransformation processes. Because of its potential use in agriculture and industry, we investigated the conditions for the optimal preservation of the strain and its derivatives for long-term storage. The highest survival rates were achieved with cells that had reached the stationary phase and which had been subjected to freeze-drying in the presence of disaccharides (trehalose, maltose, and lactose) as lyoprotectants. Using fluorescence polarization techniques, we show that cell membranes of KT2440 were more rigid in the stationary phase than in the exponential phase of growth. This is consistent with the fact that cells grown in the stationary phase exhibited a higher proportion of C 17:cyclopropane as a fatty acid than cells in the exponential phase. Mutants for the cfaB gene, which encodes the main C 17:cyclopropane synthase, and for the cfaA gene, which encodes a minor C 17:cyclopropane synthase, were constructed. These mutants were more sensitive to freeze-drying than wild-type cells, particularly the mutant with a knockout in the cfaB gene that produced less than 2% of the amount of C 17:cyclopropane produced by the parental strain.
International Archives of Allergy and Immunology, 1984
Sera of 6 patients with Chediak-Higashi syndrome and sera of their mothers were studied for heter... more Sera of 6 patients with Chediak-Higashi syndrome and sera of their mothers were studied for heterophile antibodies. Sera of 5 patients as well as 5 sera of their mothers contained antibodies against trypsinized bovine erythrocytes, tissue sediments of guinea pig kidney or high molecular weight glycoprotein (HMWGP) of bovine erythrocyte stromata. The antibodies combining with HMWGP in enzyme immunoassay belonged to IgM and IgG classes. Although none of the sera had significant titer of agglutinins against sheep erythrocytes, on the basis of absorption and inhibition studies, these antibodies seemed to belong to the Hanganutziu-Deicher group of antibodies.
Page 1. 350 REVISTA COLOMBIANA DE REUMATOLOGÍA MARIO ANDRÉS QUINTANA DUQUE & Cols. REVISTA CO... more Page 1. 350 REVISTA COLOMBIANA DE REUMATOLOGÍA MARIO ANDRÉS QUINTANA DUQUE & Cols. REVISTA COLOMBIANA DE REUMATOLOGÍA VOL. 12 No. 4, Diciembre 2005, pp. 350-361 © 2005, Asociación Colombiana de Reumatología 1. Médico interno. ...
... Enrique Toro1*, Mario Andrés Quintana Duque2*, José Félix Restrepo3, Gerardo Quintana4, Feder... more ... Enrique Toro1*, Mario Andrés Quintana Duque2*, José Félix Restrepo3, Gerardo Quintana4, Federico Rondón5, Álvaro Sánchez5, Fidencio Cons Molina6, Antonio Iglesias Gamarra7 ... a partir de la casuística obteni-da especialmente en el Hospital San Juan de Dios ...
Biochemical Systematics and Ecology, 2001
The volatile constituents of the marine sponge Ircinia felix were obtained by dynamic headspace e... more The volatile constituents of the marine sponge Ircinia felix were obtained by dynamic headspace extraction and analyzed by HRGC, HRGC-MS and HRGC-Odor at sniffing port. Fifty-nine volatiles were identified for the first time in the odor of this sponge. Hydrocarbons (32.9%), alcohols (17.8%) and carbonyl compounds (16.0%) predominated in the sponge volatile profile, followed by esters (11.6%), halogen compounds (8.6%), ethers (7.7%), nitrogen and/or sulfur compounds (4.6%) and carboxylic acids (0.8%). Among the identified volatiles, thiobismethane (commonly known as dimethylsulfide), methyl isocyanide and methyl isothiocyanate were found to be responsible for the nauseating and toxic smell emitted by the sponge and for the antimicrobial activity detected in the volatile extract. Exudation experiments in aquarium and in situ conditions revealed that thiobismethane, methyl isocyanide and methyl isothiocyanate are continuously released by the sponge. Upon injury, the concentration of these volatiles increased strongly. Hence, these substances form a chemical protective barrier which may help these sponges avoid fouling, compete for space, prevent infection in the short term, and/or signal generalist predators regarding the existence of other toxic substances in the internal tissues. # : S 0 3 0 5 -1 9 7 8 ( 0 0 ) 0 0 0 8 1 -8
... VOL. 14 No. 4 - 2007 Figura 7. Púrpura periorbitaria en amiloidosis. Figura 8. Lesiones lític... more ... VOL. 14 No. 4 - 2007 Figura 7. Púrpura periorbitaria en amiloidosis. Figura 8. Lesiones líticas en el radio y en el carpo por depósitos amiloideos en un paciente con mieloma múltiple. Figura 9. Compromiso cutáneo en tórax de pa-ciente con síndrome POEMS. ...
Biodiversity and Conservation, 2007
The genetic diversity of 76 accessions of lima bean (Phaseolus lunatus L.), collected mostly from... more The genetic diversity of 76 accessions of lima bean (Phaseolus lunatus L.), collected mostly from home gardens, was assessed with AFLPs and seed descriptors to evaluate the potential for recovering a lost ex situ collection in Cuba. The sample contained 60 accessions collected from 25 home gardens in the three main geographical regions of Cuba and represented the three cultivated types found on the island. Four more accessions were part of the former ex situ collection and the remaining 12 accessions were selected from the world bean collection held at the International Center for Tropical Agriculture. Some morphological measurements discriminated among cultivated types. The analysis of 62 polymorphic bands obtained with two AFLP primer combinations indicated that the three cultivated bean types were comparable in terms of molecular diversity and that no pattern of variation was associated with geographical distribution. However, a multiple correspondence analysis with the same molecular data detected different genetic groups. Three of these groups included all the cultivated accessions collected from home gardens, but could not be explained by the seed descriptors. The results therefore suggest that a scientifically sound collecting strategy to recover the former Cuban ex situ gene bank should consider combining geographical, morphological, and molecular data. The findings also suggest that any proposed methodologies should be considered before developing a conservation strategy based on an ex situ or combined ex situ and in situ approaches.
Crop Science, 2005
... Félix Alberto Guzmán a ,; Helmer Ayala b ,; César Azurdia b ,; Myriam Cristina Duque c and; M... more ... Félix Alberto Guzmán a ,; Helmer Ayala b ,; César Azurdia b ,; Myriam Cristina Duque c and; M. Carmen de Vicente * a. a International Plant Genetic Resources ... H4, C, C. annuum, Bap-ik, S.Juan Chamelco, A. Verapaz, 1300. ... H25, A, C. annuum, Pico de Gallina, Chisec, A. Verapaz ...
Revista De Saude Publica, 2004
Realizaram-se bioensaios para detectar a susceptibilidade de Aedes aegypti aos inseticidas químic... more Realizaram-se bioensaios para detectar a susceptibilidade de Aedes aegypti aos inseticidas químicos, temefós e cipermetrina. Os resultados mostraram que esta espécie é suscetível a temefós e apresenta resistência a cipermetrinae.
Journal of Neuroscience Research, 2009
An experimental model based on kainic acid (KA) injections replicates many phenomenological featu... more An experimental model based on kainic acid (KA) injections replicates many phenomenological features of human temporal lobe epilepsy, the most common type of epilepsy in adults. Taurine, 2-aminoethanesulfonic acid, present in high concentrations in many invertebrate and vertebrate systems, is believed to serve several important biological functions. In addition, it is believed to have a neuroprotective role against several diseases. In the present study, an experimental mouse model based on taurine pretreatment prior to KA administration has been improved to study whether taurine has a neuroprotective effect against KA-induced behavior and cell damage. Under different treatments tested, taurine's most neuroprotective effects were observed with intraperitoneal taurine injection (150 mg/kg dosage) 12 hr before KA administration. Thus, a reduction in or total absence of seizures, together with a reduction in or even disappearance of cellular and molecular KA-derived effects, was detected in mice pretreated with taurine compared with those treated only with KA. Moreover, the use of tritiated taurine revealed taurine entry into the brain, suggesting possible changes in intracellular:extracellular taurine ratios and the triggering of pathways related to neuroprotective effects. © 2008 Wiley-Liss, Inc.
Natural Product Letters, 1995
Abstract The configuration at C-18 of variabilin (1), isolated from a Caribbean sponge, Ircinia f... more Abstract The configuration at C-18 of variabilin (1), isolated from a Caribbean sponge, Ircinia felix, was established to be R. Variabilin acetate (2) was oxidatively degraded and converted into di-(R)-MTPA ester of 2-methylheptane-1, 6-diol, which was found to have 2 R-...
Biodegradation, 2010
Agaricus brasiliensis CS1, Pleurotus ostreatus H1 and Aspergillus flavus produced holocellulases ... more Agaricus brasiliensis CS1, Pleurotus ostreatus H1 and Aspergillus flavus produced holocellulases when grown in solid and submerged liquid cultures containing agro-industrial residues, including sugar cane bagasse and dirty cotton residue, as substrates. These isolates proved to be efficient producers of holocellulases under the conditions used in this screening. Bromatological analysis of agro-industrial residues showed differences in protein, fiber, hemicellulose, cellulose and lignin content. Maximal holocellulase activity (hemicellulase, cellulase and pectinase) was obtained using solid-state cultivation with 10% substrate concentration. In this case, remarkably high levels of xylanase and polygalacturonase activity (4,008 and 4,548 IU/l, respectively) were produced by A. flavus when grown in media containing corn residue, followed by P. ostreatus H1 with IU/l values of 1,900 and 3,965 when cultivated on 5% and 10% sugar cane bagasse, respectively. A. brasiliensis CS1 showed the highest reducing sugar yield (11.640 mg/ml) when grown on medium containing sugar cane bagasse. A. brasiliensis was also the most efficient producer of protein, except when cultivated on dirty cotton residue, which induced maximal production in A. flavus. Comparison of enzymatic hydrolysis of sugar cane bagasse and dirty cotton residue by crude extracts of A. brasiliensis CS1, P. ostreatus H1 and A. flavus showed that the best reducing sugar yield was achieved using sugar cane bagasse as a substrate.
We outline here some of the steps we are taking towards the development of reliable tools for qua... more We outline here some of the steps we are taking towards the development of reliable tools for quantitative predictions of thermodynamic properties of complex fluids with equations based on statistical mechanics. The long term objective is to provide a userfriendly computer code and a wide database of molecular parameters for different compounds, able to be implemented in a process simulator. We have observed that the keys of the success when using molecular modelling tools for predictions rely on the selection of the appropriate model, representative of the molecular structure, and the use of physically meaningful molecular parameters.
Alles ist sie mit einem male" La actitud de Goethe en la naturaleza 1 Menschliches allzzl Menschl... more Alles ist sie mit einem male" La actitud de Goethe en la naturaleza 1 Menschliches allzzl Menschlzches, II, Der Wanderer und sem Schatten, 125. (Kritzsche Stud~enazisgabe 2, 607): "Nur für wenige hat er gelebt und lebt er noch: fur die Meisten 1st er Nichts, als eine Fanfare der Eitelkeit, welche man von Zeit zu Zeit über die deutsche Granze hinüberblast. Goethe, nicht nur ein guter und grosser Mensch, sondern eine Cultur, Goethe ist in der Geschichte der Deutschen ein Zwischenfall ohne Folgen."
Lipids, 1997
The methanolic extract of the marine sponge Ircinia felix has yielded nine novel fatty acid ester... more The methanolic extract of the marine sponge Ircinia felix has yielded nine novel fatty acid esters, (7E, 12E, 18R, 20Z)-variabilin (5Z, 9Z)-22-methyltricosadienoate, (7E, 12E, 18R, 20Z)-variabilin (5Z, 9Z)-tetracosadienoate, (7E, 12E, 18R, 20Z)-variabilin hexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 10-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 15-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 14-methylhexadecanoate, (7E, 12E, 18R, 20Z)-variabilin 9-octadecenoate, (7E, 12E, 18R, 20Z)-variabilin octadecanoate, and (7E, 12E, 18R, 20Z)-variabilin 2,11-dimethyloctadecanoate, along with the recently described (7E, 12E, 18R, 20Z)-variabilin 11-methyloctadecanoate. The characterization of the new fatty acids (5Z, 9Z)-22-methyltricosadienoic and 2,11-dimethyloctadecanoic acids is also described. The chemical structures were determined by extensive spectroscopic, chromatographic, and chemical analyses.
Natural Product Letters, 1995
A methanol extract of the Caribbean sponge Ircinia felix afforded a mixture of fatty acid esters ... more A methanol extract of the Caribbean sponge Ircinia felix afforded a mixture of fatty acid esters of variabilin and its isomers. Among these the novel variabilin 11-methyloctadecanoate 1 was characterized on the basis of spectral, chromatographic and chemical evidence.
Theriogenology, 2004
The objective of this study was to determine the effect of a sustained propylene glycol administr... more The objective of this study was to determine the effect of a sustained propylene glycol administration to recipients of frozen/thawed in vivo derived bovine embryos. Heifers were treated with oral propylene glycol for the last 20 days before embryo transfer (n ¼ 142), and untreated as controls (n ¼ 133). Progesterone, insulin, insulin-like growth factor-I, glucose, urea and triglyceride were analysed in blood on Day 0 and Day 7 of the estrous cycle corresponding to embryo transfer. The heifers were selected as recipients when showing progesterone levels <2.0 ng/ml (Day 0) and >2.5 ng/ml (Day 7), according to corpus luteum quality on Day 7 by technicians unaware of animals treated.
Annals of Thoracic Surgery, 2000
http://ats.ctsnetjournals.org/cgi/content/full/70/1/258 on the World Wide Web at:
Atrial tachycardias are the most common cardiac arrhythmias in clinical practice, which induce ch... more Atrial tachycardias are the most common cardiac arrhythmias in clinical practice, which induce changes in atrial properties that help to perpetuate them. These changes are called "atrial remodeling". Recent studies have shown that rapid ectopic activity principally on the pulmonary veins can trigger reentrant mechanisms and lead to atrial tachycardias. However, the influences of ectopic foci location, the number of ectopic beats and its frequency on the likelihood of triggering reentries are not well known. In this work the effects of electrical remodeling were incorporated in an atrial cell model and integrated in a three-dimensional model of human atria, to develop a study of vulnerability for reentries. To carry out the study, an ectopic beat and a burst of six ectopic beats at two different frequencies were applied in six different locations in the atria. The results show greater vulnerability in the left pulmonary veins when we applied a single ectopic beat. When we increase the number of ectopic beats to six, a greater width of the vulnerable window was observed when ectopic focus frequency was high. The location, the number of ectopic beats and their frequency affect the vulnerability for reentry.
Applied and Environmental Microbiology, 2006
Pseudomonas putida KT2440, a saprophytic soil bacterium that colonizes the plant root, is a suita... more Pseudomonas putida KT2440, a saprophytic soil bacterium that colonizes the plant root, is a suitable microorganism for the removal of pollutants and a stable host for foreign genes used in biotransformation processes. Because of its potential use in agriculture and industry, we investigated the conditions for the optimal preservation of the strain and its derivatives for long-term storage. The highest survival rates were achieved with cells that had reached the stationary phase and which had been subjected to freeze-drying in the presence of disaccharides (trehalose, maltose, and lactose) as lyoprotectants. Using fluorescence polarization techniques, we show that cell membranes of KT2440 were more rigid in the stationary phase than in the exponential phase of growth. This is consistent with the fact that cells grown in the stationary phase exhibited a higher proportion of C 17:cyclopropane as a fatty acid than cells in the exponential phase. Mutants for the cfaB gene, which encodes the main C 17:cyclopropane synthase, and for the cfaA gene, which encodes a minor C 17:cyclopropane synthase, were constructed. These mutants were more sensitive to freeze-drying than wild-type cells, particularly the mutant with a knockout in the cfaB gene that produced less than 2% of the amount of C 17:cyclopropane produced by the parental strain.