Ander Campó | Universidad Nacional Mayor de San Marcos (original) (raw)
Papers by Ander Campó
Science, 2007
Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has re... more Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14 C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2011
Prolonged high secretion of glucocorticoids normally reflects a state of chronic stress, which ha... more Prolonged high secretion of glucocorticoids normally reflects a state of chronic stress, which has been associated with an increase in disease susceptibility and reduction in Darwinian fitness. Here, we hypothesize that an increase in oxidative stress accounts for the detrimental effects of prolonged high secretion of glucocorticoids. We performed a meta-analysis on studies where physiological stress was induced by administration of glucocorticoids to evaluate the magnitude of their effects on oxidative stress. Glucocorticoids have a significant effect on oxidative stress (Pearson r = 0.552), although this effect depends on the duration of treatment, and is larger in long-term experiments. Importantly, there was a significant effect on tissue, with brain and heart being the most and the least susceptible to GC-induced oxidative stress, respectively. Furthermore, effect size was larger (1) in studies using both sexes compared to males only, (2) when corticosterone rather than dexamethasone was administered and (3) in juveniles than in adults. These effects were not confounded by species, biochemical biomarker, or whether wild or laboratory animals were studied. In conclusion, our meta-analysis suggests that GC-induced oxidative stress could be a further mechanism underlying increases in disease susceptibility and decreases in Darwinian fitness observed under chronic stress.
PLOS One, 2008
Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. Howeve... more Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. However, because of appropriate immune responses and antibiotic therapy, overt mycobacterial diseases occur far less frequently. M. avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants, an affliction evocative of inflammatory bowel disease (IBD). Several agents used to treat IBD (5-ASA, methotrexate, azathioprine and its metabolite 6-MP) have recently been shown to be antiMAP antibiotics. We herein evaluate the prevalence of MAP DNA in healthy individuals and compare them with IBD patients on antiMAP antibiotics.
Bulletin of The American Meteorological Society, 2010
Thin Solid Films, 2010
The influence of internal stress anisotropy resulting from anisotropic loading in a roll-to-roll ... more The influence of internal stress anisotropy resulting from anisotropic loading in a roll-to-roll (R2R) process, and polymer substrate anisotropy on the crack onset strain (COS) of thin oxide coatings was analyzed. Experimental data obtained for R2R processed films were compared with data obtained using an isotropic sheet-to-sheet (S2S) process with the same anisotropic substrate. In the R2R case the COS was found to increase by 20% between the transverse direction and the machine direction. In the S2S case the COS was found to be independent of orientation, except at a 45°in-plane orientation with respect to the machine direction, where it was 15% higher. The internal stress in the machine direction could not be determined, presumably due to deposition-induced curvature changes of the polymer substrate, and was therefore fitted to the COS data. Fracture mechanics analysis and finite element modeling of the experimental data showed that the influence of substrate anisotropy was marginal, and that it was the process-induced internal strain in the coating which controlled the COS.
Macromolecules, 2010
By taking advantage of the orthogonal nature of thiol-ene coupling and anhydride based esterifica... more By taking advantage of the orthogonal nature of thiol-ene coupling and anhydride based esterification reactions, a facile and chemoselective strategy to dendritic macromolecules has been developed. The ability to interchange growth steps based on thiol-ene and anhydride chemistry allows the synthesis of fifth-generation dendrimers in only five steps and under benign reaction conditions. In addition, the presented coupling chemistries eliminate the traditional need for protection/deprotection steps and afford dendrimers in high yield and purity. The modularity of this strategy coupled with the latent reactivity of the alkene/hydroxyl chain ends was demonstrated by using different cores (alkene and hydroxyl functional), various AB 2 and CD 2 monomers and a range of chain end groups. As a result, three dendritic libraries were prepared which exhibited tunability of both the chemical functionality and physical properties including the fabrication of PEG hydrogels. *Corrsponding authors. MS with SCOUT-MTP Ion Source (Bruker Daltonics, Bremen) equipped with a nitrogen laser (337 nm), a gridless ion source, and reflector design. Size exclusion chromatography (SEC) analysis was performed on a TDA 301 Viscotek instrument equipped with two GMH HR -M columns with TSK-gel. Measurements were carried out at 35°C using THF (1.0 mL min -1 ) as mobile phase. A calibration method was created using narrow linear polystyrene standards. Corrections for the flow rate fluctuations were made using toluene as an internal standard.
IEEE Transactions on Automatic Control, 2000
This paper describes how to efficiently solve a robust optimal control problem using recently dev... more This paper describes how to efficiently solve a robust optimal control problem using recently developed primal-dual interior-point methods. One potential application is model predictive control. The optimization problem considered consists of a worst case quadratic performance criterion over a finite set of linear discrete-time models subject to inequality constraints on the states and control signals. The scheme has been prototyped in Matlab. To give a rough idea of the efficiencies obtained, it is possible to solve problems with more than 10 000 primal variables and 40 000 constraints on a workstation. The key to the efficient implementation is an iterative solver in conjunction with a Riccati-recursion invertible pre-conditioner for computing the search directions.
Physical Review A, 2004
Radiative lifetimes of 11 levels belonging to the 5s5p 1 P o 1 , 5snd 3 D 1,2 (n=69) and 5sns 3 ... more Radiative lifetimes of 11 levels belonging to the 5s5p 1 P o 1 , 5snd 3 D 1,2 (n=69) and 5sns 3 S 1 (n=7,8) series of Cd I , and of 5 levels of Cd II (ie, 4d 10 5p 2 P o 1∕2,3∕2 , 4d 10 6s 2 S 1∕2 , and 4d 10 5d 2 D 3∕2,5∕2 ) have been measured using the time-resolved ...
Astronomy & Astrophysics Supplement Series, 1992
Photoelectric photometry of 14 asteroids, carried out at ESO and the Hoher List Observatory durin... more Photoelectric photometry of 14 asteroids, carried out at ESO and the Hoher List Observatory during 1990 and 1991, are presented. Composite lightcurves were derived for the asteroids 140 Siwa, 238 Hypatia, 347 Pariana, 389 Industria and 1593 Fagnes. UBV colors are also given for ten of the asteroids.
Macromolecules, 2010
Dendrimer synthesis should not be tedious and time-consuming. By utilizing an AB 2 -CD 2 approach... more Dendrimer synthesis should not be tedious and time-consuming. By utilizing an AB 2 -CD 2 approach and having orthogonal, "clickable" groups on each monomer, the time for dendrimer assembly can be drastically reduced. This was shown by preparation of a sixth generation dendrimer from starting monomer units in a single day.
PLOS One, 2008
Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. Howeve... more Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. However, because of appropriate immune responses and antibiotic therapy, overt mycobacterial diseases occur far less frequently. M. avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants, an affliction evocative of inflammatory bowel disease (IBD). Several agents used to treat IBD (5-ASA, methotrexate, azathioprine and its metabolite 6-MP) have recently been shown to be antiMAP antibiotics. We herein evaluate the prevalence of MAP DNA in healthy individuals and compare them with IBD patients on antiMAP antibiotics.
Psychiatry, Psychology and Law, 2012
The aim of the study was to find ways to enhance earwitnesses’ memory for voices and content. Ano... more The aim of the study was to find ways to enhance earwitnesses’ memory for voices and content. Another aim was to evaluate an interview protocol used by the Swedish Security Service. Three different types of interviews were compared; the Cognitive Interview, the Swedish Security Service checklist, and a baseline interview. Both 11–13-year-olds (n = 119) and adults (n = 93) were exposed to an unfamiliar voice for 40 seconds and thereafter interviewed. Two weeks later, they were confronted with a seven voice line-up. The overall accuracy for correct identifications was 19.8%. No significant difference was found between the interview conditions. As for content, the results suggest that for adults, the Cognitive Interview may be beneficial for recall of a brief conversation. The checklist used by the Swedish Security Service did not have a positive effect on voice recognition, content recall or for descriptions of voices.
Journal of Cutaneous Pathology, 2006
Background: Multinucleate cell angiohistiocytoma is an infrequent and most likely non-neoplastic... more Background: Multinucleate cell angiohistiocytoma is an infrequent and most likely non-neoplastic disorder usually seen in acral regions in elderly women. It presents clinically as asymptomatic red-to-brown tumors, with a tendency to confluence. It must be distinguished from other diverse cutaneous lesions, notably dermatofibroma, Kaposi sarcoma, and angiofibroma.Methods: We report the clinical, histopathological, and immunohistochemical findings of five patients, all women aged between 51 and 78 years. All except the first presented lesions on both of the lower limbs. None of the patients developed spontaneous resolution of the lesions and one was successfully treated by cryosurgery.Comments: Multinucleate cells are characteristic, but neither exclusive nor pathognomonic, of multinucleate cell angiohistiocytoma, since they can also appear in other inflammatory, neoplastic, or reactive processes. The presence of these cells and vascular proliferation in dermis media are the principal histopathological findings in this infrequent entity. In immunohistochemical studies, the multinucleate cells are often positive for vimentin and factor XIIIa.
Journal of Cardiovascular Electrophysiology, 2006
Introduction: The apparent location of the myocytes (M cells) with the longest action potential d... more Introduction: The apparent location of the myocytes (M cells) with the longest action potential duration (APD) in a canine left ventricular (LV) wedge have been reported to shift after application of a sea anemone toxin, ATX-II. This toxin slows inactivation of INa and thus prolongs APD. Thus, M cells may exhibit dynamic functional states, rather than being a static, anatomically discrete, myocyte population. In this study, we attempted to further define and understand this phenomenon using a mathematical model of the human ventricular myocyte action potential incorporated into an in silico “wedge” preparation. Our simulations demonstrate that even under conditions of a fixed population and ratio of epicardial, M, and endocardial myocytes, the apparent anatomical position (transmural location) of the myocytes with the longest APD can shift following ATX-II treatment. This arises because the ATX-II effect, modeled as a small increase in the late or persistent Na+ current, and consequent prolongation of APD significantly changes the electrotonic interactions between ventricular myocytes in this LV wedge preparation.Methods and Results: This LV wedge model is based on bidomain equations. It corresponds to a rectangular tissue immersed in a passive and isotropic medium that represents the superfusion bath. In this theoretical work, the three known different and discrete populations of myocytes in the human left ventricle have been included: the epicardial, M, and endocardial cells. The effects of ATX-II on INa were simulated by altering the voltage-dependent steady-state inactivation of the parameters h (fast gate) and j (slow gate). As a result, in these ATX-II simulations a persistent late Na+ current was generated in all three types of ventricular myocytes. However, the APDs were prolonged in a heterogeneous pattern. Our simulations demonstrate that after the ATX-II effects develop, alterations in transmural electrotonic interactions can produce changes in the transmural location of myocytes with the longest APD.Conclusions: The combination of intercellular electrotonic interactions, which tend to reduce and smooth out the discrete transmural APD variations, and the heterogeneous effects of ATX-II, which preferentially prolong the APD of M cells, can shift the location of the ventricular myocytes. This shift results in significantly altered transmural patterns of action potential durations, which would be expected to change localized refractory period and excitability. These cellular changes give rise to alterations in the corresponding surface electrograms and may change the overall substrates for conduction and rhythm disturbances.
American Journal of Physiology-heart and Circulatory Physiology, 2009
The electrical activity of adult mouse and rat hearts has been analyzed extensively, often as a p... more The electrical activity of adult mouse and rat hearts has been analyzed extensively, often as a prerequisite for genetic engineering studies or for the development of rodent models of human diseases. Some aspects of the initiation and conduction of the cardiac action potential in rodents closely resemble those in large mammals. However, rodents have a much higher heart rate and their ventricular action potential is triangular and very short. As a consequence, an interpretation of the electrocardiogram in the mouse and rat remains difficult and controversial. In this study, optical mapping techniques have been applied to an in vitro left ventricular adult rat preparation to obtain patterns of conduction and action potential duration measurements from the epicardial surface. This information has been combined with previously published mathematical models of the rat ventricular myocyte to develop a bidomain model for action potential propagation and electrogram formation in the rat left ventricle. Important insights into the basis for the repolarization waveform in the ventricular electrogram of the adult rat have been obtained. Notably, our model demonstrated that the biphasic shape of the rat ventricular repolarization wave can be explained in terms of the transmural and apex-to-base gradients in action potential duration that exist in the rat left ventricle.
Journal of Nutrition Health & Aging, 2008
International Journal of Infectious Diseases, 2009
Similarities between human inflammatory bowel disease (IBD) and ruminant paratuberculosis have fu... more Similarities between human inflammatory bowel disease (IBD) and ruminant paratuberculosis have fueled a heated discussion on the role of Mycobacterium avium subsp. paratuberculosis (MAP) in the etiology of IBD.In order to determine microbiological and immunological evidence of an association between MAP and IBD, blood from 222 inflammatory bowel disease patients and 80 healthy donors from the Basque Country (Spain) were subjected to nested PCR for MAP-specific insertion sequence IS900, interferon-γ (IFN-γ) release test with PPA-3 MAP antigen (IFNMAP) or phosphate-buffered saline (IFNPBS), and antibody ELISA with PPA-3 MAP antigen (ABMAP).Highly significant differences in the proportion of PCR-positive IBD patients (17%) and healthy controls (43%) as well as lower IFNMAP and higher ABMAP and IFNPBS responses were observed. Treatment was associated with decreases in IFNMAP and PCR-positive frequency.These results indicate the existence of immune responses and treatment interactions with MAP that strongly support an etiological role of this agent in IBD.
Bulletin of The American Meteorological Society, 2003
MAY 2003 AMERICAN METEOROLOGICAL SOCIETY | T he stratocumulus-topped boundary layer (hereafter th... more MAY 2003 AMERICAN METEOROLOGICAL SOCIETY | T he stratocumulus-topped boundary layer (hereafter the STBL), which prevails in the subtropics in regions where the underlying ocean is much colder than the overlying atmosphere, is thought to be an important component of the climate system. Perhaps most striking is its impact on the radiative balance at the top of the atmosphere. The seasonally averaged net cloud radiative forcing from the STBL has been estimated to be as large as 70 W m −2 (Stephens and Greenwald 1991), more than an order of magnitude larger than the radiative forcing associated with a doubling of atmospheric CO 2 . This means that even rather subtle sensitivities of the STBL to changes in the properties of the atmospheric aero-Measurements in marine stratocumulus over the northeast Pacific help scientists unravel the mysteries of this important cloud regime.
Water Science and Technology, 1998
ABSTRACT
Science, 2007
Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has re... more Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14 C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2011
Prolonged high secretion of glucocorticoids normally reflects a state of chronic stress, which ha... more Prolonged high secretion of glucocorticoids normally reflects a state of chronic stress, which has been associated with an increase in disease susceptibility and reduction in Darwinian fitness. Here, we hypothesize that an increase in oxidative stress accounts for the detrimental effects of prolonged high secretion of glucocorticoids. We performed a meta-analysis on studies where physiological stress was induced by administration of glucocorticoids to evaluate the magnitude of their effects on oxidative stress. Glucocorticoids have a significant effect on oxidative stress (Pearson r = 0.552), although this effect depends on the duration of treatment, and is larger in long-term experiments. Importantly, there was a significant effect on tissue, with brain and heart being the most and the least susceptible to GC-induced oxidative stress, respectively. Furthermore, effect size was larger (1) in studies using both sexes compared to males only, (2) when corticosterone rather than dexamethasone was administered and (3) in juveniles than in adults. These effects were not confounded by species, biochemical biomarker, or whether wild or laboratory animals were studied. In conclusion, our meta-analysis suggests that GC-induced oxidative stress could be a further mechanism underlying increases in disease susceptibility and decreases in Darwinian fitness observed under chronic stress.
PLOS One, 2008
Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. Howeve... more Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. However, because of appropriate immune responses and antibiotic therapy, overt mycobacterial diseases occur far less frequently. M. avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants, an affliction evocative of inflammatory bowel disease (IBD). Several agents used to treat IBD (5-ASA, methotrexate, azathioprine and its metabolite 6-MP) have recently been shown to be antiMAP antibiotics. We herein evaluate the prevalence of MAP DNA in healthy individuals and compare them with IBD patients on antiMAP antibiotics.
Bulletin of The American Meteorological Society, 2010
Thin Solid Films, 2010
The influence of internal stress anisotropy resulting from anisotropic loading in a roll-to-roll ... more The influence of internal stress anisotropy resulting from anisotropic loading in a roll-to-roll (R2R) process, and polymer substrate anisotropy on the crack onset strain (COS) of thin oxide coatings was analyzed. Experimental data obtained for R2R processed films were compared with data obtained using an isotropic sheet-to-sheet (S2S) process with the same anisotropic substrate. In the R2R case the COS was found to increase by 20% between the transverse direction and the machine direction. In the S2S case the COS was found to be independent of orientation, except at a 45°in-plane orientation with respect to the machine direction, where it was 15% higher. The internal stress in the machine direction could not be determined, presumably due to deposition-induced curvature changes of the polymer substrate, and was therefore fitted to the COS data. Fracture mechanics analysis and finite element modeling of the experimental data showed that the influence of substrate anisotropy was marginal, and that it was the process-induced internal strain in the coating which controlled the COS.
Macromolecules, 2010
By taking advantage of the orthogonal nature of thiol-ene coupling and anhydride based esterifica... more By taking advantage of the orthogonal nature of thiol-ene coupling and anhydride based esterification reactions, a facile and chemoselective strategy to dendritic macromolecules has been developed. The ability to interchange growth steps based on thiol-ene and anhydride chemistry allows the synthesis of fifth-generation dendrimers in only five steps and under benign reaction conditions. In addition, the presented coupling chemistries eliminate the traditional need for protection/deprotection steps and afford dendrimers in high yield and purity. The modularity of this strategy coupled with the latent reactivity of the alkene/hydroxyl chain ends was demonstrated by using different cores (alkene and hydroxyl functional), various AB 2 and CD 2 monomers and a range of chain end groups. As a result, three dendritic libraries were prepared which exhibited tunability of both the chemical functionality and physical properties including the fabrication of PEG hydrogels. *Corrsponding authors. MS with SCOUT-MTP Ion Source (Bruker Daltonics, Bremen) equipped with a nitrogen laser (337 nm), a gridless ion source, and reflector design. Size exclusion chromatography (SEC) analysis was performed on a TDA 301 Viscotek instrument equipped with two GMH HR -M columns with TSK-gel. Measurements were carried out at 35°C using THF (1.0 mL min -1 ) as mobile phase. A calibration method was created using narrow linear polystyrene standards. Corrections for the flow rate fluctuations were made using toluene as an internal standard.
IEEE Transactions on Automatic Control, 2000
This paper describes how to efficiently solve a robust optimal control problem using recently dev... more This paper describes how to efficiently solve a robust optimal control problem using recently developed primal-dual interior-point methods. One potential application is model predictive control. The optimization problem considered consists of a worst case quadratic performance criterion over a finite set of linear discrete-time models subject to inequality constraints on the states and control signals. The scheme has been prototyped in Matlab. To give a rough idea of the efficiencies obtained, it is possible to solve problems with more than 10 000 primal variables and 40 000 constraints on a workstation. The key to the efficient implementation is an iterative solver in conjunction with a Riccati-recursion invertible pre-conditioner for computing the search directions.
Physical Review A, 2004
Radiative lifetimes of 11 levels belonging to the 5s5p 1 P o 1 , 5snd 3 D 1,2 (n=69) and 5sns 3 ... more Radiative lifetimes of 11 levels belonging to the 5s5p 1 P o 1 , 5snd 3 D 1,2 (n=69) and 5sns 3 S 1 (n=7,8) series of Cd I , and of 5 levels of Cd II (ie, 4d 10 5p 2 P o 1∕2,3∕2 , 4d 10 6s 2 S 1∕2 , and 4d 10 5d 2 D 3∕2,5∕2 ) have been measured using the time-resolved ...
Astronomy & Astrophysics Supplement Series, 1992
Photoelectric photometry of 14 asteroids, carried out at ESO and the Hoher List Observatory durin... more Photoelectric photometry of 14 asteroids, carried out at ESO and the Hoher List Observatory during 1990 and 1991, are presented. Composite lightcurves were derived for the asteroids 140 Siwa, 238 Hypatia, 347 Pariana, 389 Industria and 1593 Fagnes. UBV colors are also given for ten of the asteroids.
Macromolecules, 2010
Dendrimer synthesis should not be tedious and time-consuming. By utilizing an AB 2 -CD 2 approach... more Dendrimer synthesis should not be tedious and time-consuming. By utilizing an AB 2 -CD 2 approach and having orthogonal, "clickable" groups on each monomer, the time for dendrimer assembly can be drastically reduced. This was shown by preparation of a sixth generation dendrimer from starting monomer units in a single day.
PLOS One, 2008
Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. Howeve... more Background: Mycobacteria, such as M. leprae and M. tuberculosis infect billions of humans. However, because of appropriate immune responses and antibiotic therapy, overt mycobacterial diseases occur far less frequently. M. avium subspecies paratuberculosis (MAP) causes Johne's disease in ruminants, an affliction evocative of inflammatory bowel disease (IBD). Several agents used to treat IBD (5-ASA, methotrexate, azathioprine and its metabolite 6-MP) have recently been shown to be antiMAP antibiotics. We herein evaluate the prevalence of MAP DNA in healthy individuals and compare them with IBD patients on antiMAP antibiotics.
Psychiatry, Psychology and Law, 2012
The aim of the study was to find ways to enhance earwitnesses’ memory for voices and content. Ano... more The aim of the study was to find ways to enhance earwitnesses’ memory for voices and content. Another aim was to evaluate an interview protocol used by the Swedish Security Service. Three different types of interviews were compared; the Cognitive Interview, the Swedish Security Service checklist, and a baseline interview. Both 11–13-year-olds (n = 119) and adults (n = 93) were exposed to an unfamiliar voice for 40 seconds and thereafter interviewed. Two weeks later, they were confronted with a seven voice line-up. The overall accuracy for correct identifications was 19.8%. No significant difference was found between the interview conditions. As for content, the results suggest that for adults, the Cognitive Interview may be beneficial for recall of a brief conversation. The checklist used by the Swedish Security Service did not have a positive effect on voice recognition, content recall or for descriptions of voices.
Journal of Cutaneous Pathology, 2006
Background: Multinucleate cell angiohistiocytoma is an infrequent and most likely non-neoplastic... more Background: Multinucleate cell angiohistiocytoma is an infrequent and most likely non-neoplastic disorder usually seen in acral regions in elderly women. It presents clinically as asymptomatic red-to-brown tumors, with a tendency to confluence. It must be distinguished from other diverse cutaneous lesions, notably dermatofibroma, Kaposi sarcoma, and angiofibroma.Methods: We report the clinical, histopathological, and immunohistochemical findings of five patients, all women aged between 51 and 78 years. All except the first presented lesions on both of the lower limbs. None of the patients developed spontaneous resolution of the lesions and one was successfully treated by cryosurgery.Comments: Multinucleate cells are characteristic, but neither exclusive nor pathognomonic, of multinucleate cell angiohistiocytoma, since they can also appear in other inflammatory, neoplastic, or reactive processes. The presence of these cells and vascular proliferation in dermis media are the principal histopathological findings in this infrequent entity. In immunohistochemical studies, the multinucleate cells are often positive for vimentin and factor XIIIa.
Journal of Cardiovascular Electrophysiology, 2006
Introduction: The apparent location of the myocytes (M cells) with the longest action potential d... more Introduction: The apparent location of the myocytes (M cells) with the longest action potential duration (APD) in a canine left ventricular (LV) wedge have been reported to shift after application of a sea anemone toxin, ATX-II. This toxin slows inactivation of INa and thus prolongs APD. Thus, M cells may exhibit dynamic functional states, rather than being a static, anatomically discrete, myocyte population. In this study, we attempted to further define and understand this phenomenon using a mathematical model of the human ventricular myocyte action potential incorporated into an in silico “wedge” preparation. Our simulations demonstrate that even under conditions of a fixed population and ratio of epicardial, M, and endocardial myocytes, the apparent anatomical position (transmural location) of the myocytes with the longest APD can shift following ATX-II treatment. This arises because the ATX-II effect, modeled as a small increase in the late or persistent Na+ current, and consequent prolongation of APD significantly changes the electrotonic interactions between ventricular myocytes in this LV wedge preparation.Methods and Results: This LV wedge model is based on bidomain equations. It corresponds to a rectangular tissue immersed in a passive and isotropic medium that represents the superfusion bath. In this theoretical work, the three known different and discrete populations of myocytes in the human left ventricle have been included: the epicardial, M, and endocardial cells. The effects of ATX-II on INa were simulated by altering the voltage-dependent steady-state inactivation of the parameters h (fast gate) and j (slow gate). As a result, in these ATX-II simulations a persistent late Na+ current was generated in all three types of ventricular myocytes. However, the APDs were prolonged in a heterogeneous pattern. Our simulations demonstrate that after the ATX-II effects develop, alterations in transmural electrotonic interactions can produce changes in the transmural location of myocytes with the longest APD.Conclusions: The combination of intercellular electrotonic interactions, which tend to reduce and smooth out the discrete transmural APD variations, and the heterogeneous effects of ATX-II, which preferentially prolong the APD of M cells, can shift the location of the ventricular myocytes. This shift results in significantly altered transmural patterns of action potential durations, which would be expected to change localized refractory period and excitability. These cellular changes give rise to alterations in the corresponding surface electrograms and may change the overall substrates for conduction and rhythm disturbances.
American Journal of Physiology-heart and Circulatory Physiology, 2009
The electrical activity of adult mouse and rat hearts has been analyzed extensively, often as a p... more The electrical activity of adult mouse and rat hearts has been analyzed extensively, often as a prerequisite for genetic engineering studies or for the development of rodent models of human diseases. Some aspects of the initiation and conduction of the cardiac action potential in rodents closely resemble those in large mammals. However, rodents have a much higher heart rate and their ventricular action potential is triangular and very short. As a consequence, an interpretation of the electrocardiogram in the mouse and rat remains difficult and controversial. In this study, optical mapping techniques have been applied to an in vitro left ventricular adult rat preparation to obtain patterns of conduction and action potential duration measurements from the epicardial surface. This information has been combined with previously published mathematical models of the rat ventricular myocyte to develop a bidomain model for action potential propagation and electrogram formation in the rat left ventricle. Important insights into the basis for the repolarization waveform in the ventricular electrogram of the adult rat have been obtained. Notably, our model demonstrated that the biphasic shape of the rat ventricular repolarization wave can be explained in terms of the transmural and apex-to-base gradients in action potential duration that exist in the rat left ventricle.
Journal of Nutrition Health & Aging, 2008
International Journal of Infectious Diseases, 2009
Similarities between human inflammatory bowel disease (IBD) and ruminant paratuberculosis have fu... more Similarities between human inflammatory bowel disease (IBD) and ruminant paratuberculosis have fueled a heated discussion on the role of Mycobacterium avium subsp. paratuberculosis (MAP) in the etiology of IBD.In order to determine microbiological and immunological evidence of an association between MAP and IBD, blood from 222 inflammatory bowel disease patients and 80 healthy donors from the Basque Country (Spain) were subjected to nested PCR for MAP-specific insertion sequence IS900, interferon-γ (IFN-γ) release test with PPA-3 MAP antigen (IFNMAP) or phosphate-buffered saline (IFNPBS), and antibody ELISA with PPA-3 MAP antigen (ABMAP).Highly significant differences in the proportion of PCR-positive IBD patients (17%) and healthy controls (43%) as well as lower IFNMAP and higher ABMAP and IFNPBS responses were observed. Treatment was associated with decreases in IFNMAP and PCR-positive frequency.These results indicate the existence of immune responses and treatment interactions with MAP that strongly support an etiological role of this agent in IBD.
Bulletin of The American Meteorological Society, 2003
MAY 2003 AMERICAN METEOROLOGICAL SOCIETY | T he stratocumulus-topped boundary layer (hereafter th... more MAY 2003 AMERICAN METEOROLOGICAL SOCIETY | T he stratocumulus-topped boundary layer (hereafter the STBL), which prevails in the subtropics in regions where the underlying ocean is much colder than the overlying atmosphere, is thought to be an important component of the climate system. Perhaps most striking is its impact on the radiative balance at the top of the atmosphere. The seasonally averaged net cloud radiative forcing from the STBL has been estimated to be as large as 70 W m −2 (Stephens and Greenwald 1991), more than an order of magnitude larger than the radiative forcing associated with a doubling of atmospheric CO 2 . This means that even rather subtle sensitivities of the STBL to changes in the properties of the atmospheric aero-Measurements in marine stratocumulus over the northeast Pacific help scientists unravel the mysteries of this important cloud regime.
Water Science and Technology, 1998
ABSTRACT