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Papers by juan fernando candia roman
Revista De Investigacion Economica Y Social De Castilla Y Leon, 2007
a través de sus presupuestos liquidados de ingresos y gastos, para lo cual se ha desarrollado una... more a través de sus presupuestos liquidados de ingresos y gastos, para lo cual se ha desarrollado una metodología de incidencia fiscal que se ha aplicado a un municipio de Castilla y León en los
Diagnosis de la familia: Individuos solitarios; cuerpo en forma de saco, no dividido en regiones;... more Diagnosis de la familia: Individuos solitarios; cuerpo en forma de saco, no dividido en regiones; el tubo digestivo se localiza en la parte derecha del cuerpo; la parte interna de la branquia posee senos longitudinales y los estigmas pueden ser rectos o espirales; las gónadas se encuentran dentro del lazo intestinal
Revista medica de Chile
Metallo-beta-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Ps... more Metallo-beta-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. To detect the presence of MBL in imipenem resistant Psae strains. Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains were studied by pulse field gel electrophoresis. The presence of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. All the strains were also multiresistant. The presence of MBL was detected in 19% of imipenem resistant Psae strains.
Revista chilena de infectología, 2014
Declaración de conflictos de interés: PG ha recibido apoyo para viajes a congresos y charlas de M... more Declaración de conflictos de interés: PG ha recibido apoyo para viajes a congresos y charlas de Merck Sharpe & Dohme, Novartis, Pfizer, Rochem, bioMerieux, Copan, Beckton Dickinson. El resto de los autores declaran no tener conflictos de interés.
Revista chilena de infectología, 2011
Clinical and molecular characterization of ESBL-producing enterobacteria isolated from bacteremia... more Clinical and molecular characterization of ESBL-producing enterobacteria isolated from bacteremia in a university hospital Introduction: Extended-spectrum--lactamases (ESBL) are plasmid-encoded enzymes that confer resistance to multiple antimicrobials. ESBL-producing enterobacteria that cause bacteremia limit therapeutic options and increase mortality. Objective: To perform a clinical and molecular description of bacteremia caused by ESBLproducing enterobacteria. Method: We retrospectively studied the cases of bacteremia due to ESBL-producing Escherichia coli, Klebsiella pneumoniae and Proteus spp in adults admitted to a university hospital during the years 2004-2007. We reviewed the clinical records and antimicrobial susceptibility patterns. Molecular typing was performed by polymerase chain reaction and study of clonality by pulsed-fi eld electrophoresis. Results: We found a prevalence of 9.8% ESBL in enterobacteria causing bacteremia. Decreased susceptibility to quinolones and aminoglycosides was observed, without resistance to carbapenems. The predominant ESBL types were CTX-M (96%), TEM (62%) and GES (28%). 79% of the strains presented more than one type of ESBL. Clinical analysis revealed high prevalence of risk factors, previous use of antimicrobials and of invasive devices. There was no signifi cant clonality. Conclusion: The presence of ESBLs in bloodstream infections is a clinical problem that must be considered when choosing empiric therapy.
Revista chilena de infectología, 2013
Los autores declaran no tener conflictos de interés respecto a este artículo.
Revista chilena de infectología, 2012
A comparative study for adenosine deaminase and anti-antigen A-60 antibodies detection for the di... more A comparative study for adenosine deaminase and anti-antigen A-60 antibodies detection for the diagnosis of tuberculous meningitis Background: Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of rapid and accurate diagnostic tools. We evaluated the immunological response to Mycobacterium tuberculosis anti-A60 antibodies in cerebrospinal fluid (CSF) in comparison to adenosine deaminase (ADA) determination, for the diagnosis of TBM. Methods: A total of 63 CSF samples were analyzed by indirect ELISA for the detection of anti-A60 IgG, IgM and IgA. These include samples from 17 patients with confirmed TBM and 46 control patients with other infections. Results: The mean individual anti-A60 IgM, IgG and IgA CSF antibody titers were significantly higher in TBM in comparison with control groups (p < 0.01). The best discriminatory CSF antibody for confirming TBM diagnosis was IgM, with an area under the receiver operating characteristic curve of 0.928 (95%CI 0.834-0.978), compared to 0.863 (95% CI: 0.752-0.936) for ADA testing (p = NS). The sensitivity of anti-A60 IgM CSF antibody titers (cutoff > 0.06 U/ml) was 94.1% compared to 88.2% for ADA (cutoff > 6.2 U/ml), p = NS. Both anti A60 IgM and ADA showed the same moderate specificity (80.4%). Two cases of TBM were correctly identified by anti-A60 IgM but missed by ADA. Conclusion: The ELISA test for anti-antigen A60 antibodies (IgM) is a rapid and sensitive tool for the rapid diagnosis of TBM that can be a complement to ADA determination. The specificity of both tests is still a limitation in TBM diagnosis.
Revista médica de Chile, 2011
Resistance phenotypes and genotypes of Streptococcus pyogenes clinical isolates in Chile over a 1... more Resistance phenotypes and genotypes of Streptococcus pyogenes clinical isolates in Chile over a 10-year period Background: Macrolide and lincosamide resistance in Streptococcus pyogenes is due to the acquisition of mef, ermB and ermA genes, which confer different resistance phenotypes, namely M, MLSBconstitutive and MLSBinducible respectively. The last report of resistance in Chile was done in the period 1990-1998, in which resistance to macrolides was 5.4%, with M phenotype as the predominant one. Aim: To characterize the evolution of erythromycin and clindamycin resistance and their associated genes in S. pyogenes strains isolated from patients with invasive and noninvasive infections in the period 1996 to 2005. Material and Methods: Resistance to erythromycin and clindamycin was determined in 1,282 clinical isolates using the disk diffusion test. Resistant isolates were analyzed by polymerase chain reaction (PCR) for the presence of the above mentioned resistance genes. Results: Global resistance to erythromycin and clindamycin was 3.5 and 0.7% respectively. Eighty percent of the resistant strains possessed the M. phenotype. Conclusions: Resistance levels of S. pyogenes have decreased in Chile in the last years. Most resistant strains have M phenotype in contrast to many countries in which the MLSB constitutive phenotype is the predominant one.
International Journal of Morphology, 2013
Fueron evaluados 621 estudiantes, con un rango de edad de 6 a 13 años. A cada niño se le tomaron,... more Fueron evaluados 621 estudiantes, con un rango de edad de 6 a 13 años. A cada niño se le tomaron, medidas antropométricas de peso, talla, circunferencia de cintura, pliegue de tríceps y de pantorrilla; se utilizó el programa Epi Info Versión 3.3.2 para calcular el índice de masa corporal (IMC), estableciendo como obesidad un valor mayor o igual al percentil 95 y el sobrepeso un valor mayor o igual al percentil 85 y menor al 95 de acuerdo con la edad y sexo, tomando en cuenta la medición de circunferencia de cintura se determinó obesidad abdominal mayor o igual al percentil 90 de acuerdo con la edad y sexo; el porcentaje de grasa corporal de determino por la ecuación de slaughter. Las variables con prevalencias más altas resultaron las del estado nutricional, con donde el 19,1% de la población estudiada presentó sobrepeso y 25,1% obesidad. La prevalencia combinada de sobrepeso y obesidad en niños fue de 51,3% mientras que en niñas 37,4%. Los resultados encontrados en estos niños muestran claramente altas prevalencias de sobrepeso y obesidad. Inclusive más altas al promedio de los niños mexicanos. Concluyendo que en esta escuela es necesario tomar medidas, como poner en marcha programas de actividad física y nutrición orientados a frenar el problema del sobrepeso y obesidad.
Revista chilena de infectología, 2009
Assessment of the Amplicor PCR® for the detection of Mycobacterium tuberculosis in smear negative... more Assessment of the Amplicor PCR® for the detection of Mycobacterium tuberculosis in smear negative respiratory and non respiratory specimens: A retrospective analysis Background: Commercial polymerase chain reaction (PCR) kits are widely accepted for analysis of smear positive respiratory specimens, but the sensitivity is variable for smear negative ones. Objective: To assess the PCR method usefulness in smear negative respiratory and non respiratory specimens. Methods: We compared the PCR results (AMPLICOR MTB test™, Roche) of 235 specimens subjected to culture in Loewenstein-Jensen agar (as the gold standard). Results: 181 (76%) were respiratory and 54 (24%) extra-respiratory specimens. The sensitivity was 88% and 50%, respectively, specificity and PPV was 100% in both cases. NPV was 99.4% in respiratory specimens and 96.1% in non-respiratory specimens. Conclusions: The good performance of this PCR in smear negative respiratory specimens allows the clinician to take decisions based on the result of this exam. In extra-respiratory specimens the contribution is important only when the PCR result is positive.
Revista chilena de infectología, 2013
Surveillance of carbapenem-resistant enterobacteria in stool cultures in a university hospital in... more Surveillance of carbapenem-resistant enterobacteria in stool cultures in a university hospital in Santiago, Chile Background: Clinical cultures detect only one-third of colonized patients with carbapenem-resistant Enterobacteriaceae. Early identification and contact precautions implementation would help to interrupt transmission. In our hospital no carbapenemase-producing enterobacteria infections have been described. Aim: To perform stool surveillance cultures in patients hospitalized in critical care unit with the purpose to detect carbapenemase-producing Enterobacteriacea. Material and Methods: Rectal swabs were obtained of patients after five or more days of hospital stay, on a monthly basis from July to December 2011. Phenotypic assays (modified test Hodge and phenylboronic acid test) and polymerase chain reaction (PCR) searching for six carbapenemases of group A and B of Ambler`s classification were performed. Results: During this period, 241 surveillance rectal cultures were performed. Thirty eight enterobacteria isolated from 30 patients presented a decreased susceptibility to carbapenems by agar dilution method. All PCR were negative. Conclusion: We found that despite the significant number of resistant isolates, patients hospitalized in our institution are not colonized with carbapenemase-producing Enterobacteriaceae. We highlight the importance of screening before having the problem in place.
Virology, 2002
Epidemiologically, certain human papillomaviruses are positively associated with cervical cancer,... more Epidemiologically, certain human papillomaviruses are positively associated with cervical cancer, while adeno-associated viruses (AAV-2) are negatively associated with this same cancer. Both HPV and AAV productively replicate in differentiating keratinocytes of the skin and interact with each other. However, AAV has a relatively fast life cycle, generating infectious progeny by the third to fourth day of an organotypic epithelial raft culture. In contrast, HPV is slow, generating infectious progeny only after 10-12 days. As earlier studies indicated that these two skin-tropic virus types significantly affect each other's life cycle, we investigated if the temporal kinetics of the slow HPV life cycle was affected by the fast AAV in raft cultures. Here it is shown that the presence of AAV-2 at a variety of multiplicities of infection (m.o.i.) resulted in early onset HPV-31b DNA replication. Using plasmids which each expressed only one of the four rep proteins, an enhancement affect was seen for all four rep proteins of AAV, with Rep40 having the highest activity. Furthermore, AAV (m.o.i. of 5) also resulted in a temporally accelerated production of HPV infectious units, seen as early as Day 4, with high levels of viral progeny being produced by Day 6.5. Like earlier studies at Day 12, histological differences were seen at Day 6.5 between AAV-infected and mock-infected HPV/rafts. These data suggest that under specific conditions the AAV rep trans-factors can positively regulate HPV gene expression in addition to the usual negative regulation that has been consistently observed by the rep proteins. These data also suggest that AAV has a significant effect upon the temporal kinetics of the HPV life cycle in natural host tissue. However, it is unclear if or how this AAV-induced fast HPV life cycle mechanistically correlates with lower rates of HPV-associated cervical disease.
Strain, 1999
Orthognatic surgeons have a requirement for the measurement of stress distribution within the hum... more Orthognatic surgeons have a requirement for the measurement of stress distribution within the human lower jaw, in order to aid and improve surgical procedures. Validation of finite element modelling data describing mandible behaviour which has previously been attempted using holographic interferometry. Electronic speckle pattern interferometry (ESPI), a whole field non‐contact optical technique has been applied to the study of a dry human mandible under load. This technique improves over previous methods by generating discrete quantitative displacement and strain components. The optical analysis of a dry mandible is described, with the results viewed in ‘real time’ as progressively greater forces were applied on the lower border of the chin, in the upwards (impact) direction with biting boundary conditions included in the experimental model. This has shown that the bone tissue holding the front teeth transmits the forces impacting on the chin, which are absorbed by the basal bone of the mandible.
Optical Engineering, 1998
A simple and low-cost laser writing system that allows one to obtain micrometer features with hig... more A simple and low-cost laser writing system that allows one to obtain micrometer features with high-quality borders is presented. After an overview of the complete fabrication process of masks to carry out the ion-exchange technique in glass in a selective way, a complete ...
Journal of Modern Optics, 2005
In an effort to find a non-contact technique capable of providing measurements of in-plane strain... more In an effort to find a non-contact technique capable of providing measurements of in-plane strain, the authors designed a speckle shearing interferometer using symmetrical coherent illumination. It is presented the analysis of the sensitivity to displacement and strain of this interferometer, together with the analysis of the phase-stepping of the resultant fringe patterns. A new notation is introduced alongside this analysis to define the interference components in speckle shearing interferometers using multiple illumination beams. Experimental results show the fringe patterns and the phase stepping, in support of the theoretical analysis.
Journal of Modern Optics, 1999
The common digital speckle pattern correlation is a non-contact optical technique which allows th... more The common digital speckle pattern correlation is a non-contact optical technique which allows the measurement of the surface deformation of a test object after it has been exposed to external factors (high temperatures, mechanical stress, humidity, etc.). This technique uses a ...
Journal of Modern Optics, 1997
. A simple, low cost system useful in laser writing processes to set the focal spot on the substr... more . A simple, low cost system useful in laser writing processes to set the focal spot on the substrate surface with micrometre precision is described. Evaluation of its sensitivity is also presented. The lack of essential critical adjustments accounts for the utility of this system and its ...
Journal of Modern Optics, 2006
Revista De Investigacion Economica Y Social De Castilla Y Leon, 2007
a través de sus presupuestos liquidados de ingresos y gastos, para lo cual se ha desarrollado una... more a través de sus presupuestos liquidados de ingresos y gastos, para lo cual se ha desarrollado una metodología de incidencia fiscal que se ha aplicado a un municipio de Castilla y León en los
Diagnosis de la familia: Individuos solitarios; cuerpo en forma de saco, no dividido en regiones;... more Diagnosis de la familia: Individuos solitarios; cuerpo en forma de saco, no dividido en regiones; el tubo digestivo se localiza en la parte derecha del cuerpo; la parte interna de la branquia posee senos longitudinales y los estigmas pueden ser rectos o espirales; las gónadas se encuentran dentro del lazo intestinal
Revista medica de Chile
Metallo-beta-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Ps... more Metallo-beta-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. To detect the presence of MBL in imipenem resistant Psae strains. Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains were studied by pulse field gel electrophoresis. The presence of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. All the strains were also multiresistant. The presence of MBL was detected in 19% of imipenem resistant Psae strains.
Revista chilena de infectología, 2014
Declaración de conflictos de interés: PG ha recibido apoyo para viajes a congresos y charlas de M... more Declaración de conflictos de interés: PG ha recibido apoyo para viajes a congresos y charlas de Merck Sharpe & Dohme, Novartis, Pfizer, Rochem, bioMerieux, Copan, Beckton Dickinson. El resto de los autores declaran no tener conflictos de interés.
Revista chilena de infectología, 2011
Clinical and molecular characterization of ESBL-producing enterobacteria isolated from bacteremia... more Clinical and molecular characterization of ESBL-producing enterobacteria isolated from bacteremia in a university hospital Introduction: Extended-spectrum--lactamases (ESBL) are plasmid-encoded enzymes that confer resistance to multiple antimicrobials. ESBL-producing enterobacteria that cause bacteremia limit therapeutic options and increase mortality. Objective: To perform a clinical and molecular description of bacteremia caused by ESBLproducing enterobacteria. Method: We retrospectively studied the cases of bacteremia due to ESBL-producing Escherichia coli, Klebsiella pneumoniae and Proteus spp in adults admitted to a university hospital during the years 2004-2007. We reviewed the clinical records and antimicrobial susceptibility patterns. Molecular typing was performed by polymerase chain reaction and study of clonality by pulsed-fi eld electrophoresis. Results: We found a prevalence of 9.8% ESBL in enterobacteria causing bacteremia. Decreased susceptibility to quinolones and aminoglycosides was observed, without resistance to carbapenems. The predominant ESBL types were CTX-M (96%), TEM (62%) and GES (28%). 79% of the strains presented more than one type of ESBL. Clinical analysis revealed high prevalence of risk factors, previous use of antimicrobials and of invasive devices. There was no signifi cant clonality. Conclusion: The presence of ESBLs in bloodstream infections is a clinical problem that must be considered when choosing empiric therapy.
Revista chilena de infectología, 2013
Los autores declaran no tener conflictos de interés respecto a este artículo.
Revista chilena de infectología, 2012
A comparative study for adenosine deaminase and anti-antigen A-60 antibodies detection for the di... more A comparative study for adenosine deaminase and anti-antigen A-60 antibodies detection for the diagnosis of tuberculous meningitis Background: Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of rapid and accurate diagnostic tools. We evaluated the immunological response to Mycobacterium tuberculosis anti-A60 antibodies in cerebrospinal fluid (CSF) in comparison to adenosine deaminase (ADA) determination, for the diagnosis of TBM. Methods: A total of 63 CSF samples were analyzed by indirect ELISA for the detection of anti-A60 IgG, IgM and IgA. These include samples from 17 patients with confirmed TBM and 46 control patients with other infections. Results: The mean individual anti-A60 IgM, IgG and IgA CSF antibody titers were significantly higher in TBM in comparison with control groups (p < 0.01). The best discriminatory CSF antibody for confirming TBM diagnosis was IgM, with an area under the receiver operating characteristic curve of 0.928 (95%CI 0.834-0.978), compared to 0.863 (95% CI: 0.752-0.936) for ADA testing (p = NS). The sensitivity of anti-A60 IgM CSF antibody titers (cutoff > 0.06 U/ml) was 94.1% compared to 88.2% for ADA (cutoff > 6.2 U/ml), p = NS. Both anti A60 IgM and ADA showed the same moderate specificity (80.4%). Two cases of TBM were correctly identified by anti-A60 IgM but missed by ADA. Conclusion: The ELISA test for anti-antigen A60 antibodies (IgM) is a rapid and sensitive tool for the rapid diagnosis of TBM that can be a complement to ADA determination. The specificity of both tests is still a limitation in TBM diagnosis.
Revista médica de Chile, 2011
Resistance phenotypes and genotypes of Streptococcus pyogenes clinical isolates in Chile over a 1... more Resistance phenotypes and genotypes of Streptococcus pyogenes clinical isolates in Chile over a 10-year period Background: Macrolide and lincosamide resistance in Streptococcus pyogenes is due to the acquisition of mef, ermB and ermA genes, which confer different resistance phenotypes, namely M, MLSBconstitutive and MLSBinducible respectively. The last report of resistance in Chile was done in the period 1990-1998, in which resistance to macrolides was 5.4%, with M phenotype as the predominant one. Aim: To characterize the evolution of erythromycin and clindamycin resistance and their associated genes in S. pyogenes strains isolated from patients with invasive and noninvasive infections in the period 1996 to 2005. Material and Methods: Resistance to erythromycin and clindamycin was determined in 1,282 clinical isolates using the disk diffusion test. Resistant isolates were analyzed by polymerase chain reaction (PCR) for the presence of the above mentioned resistance genes. Results: Global resistance to erythromycin and clindamycin was 3.5 and 0.7% respectively. Eighty percent of the resistant strains possessed the M. phenotype. Conclusions: Resistance levels of S. pyogenes have decreased in Chile in the last years. Most resistant strains have M phenotype in contrast to many countries in which the MLSB constitutive phenotype is the predominant one.
International Journal of Morphology, 2013
Fueron evaluados 621 estudiantes, con un rango de edad de 6 a 13 años. A cada niño se le tomaron,... more Fueron evaluados 621 estudiantes, con un rango de edad de 6 a 13 años. A cada niño se le tomaron, medidas antropométricas de peso, talla, circunferencia de cintura, pliegue de tríceps y de pantorrilla; se utilizó el programa Epi Info Versión 3.3.2 para calcular el índice de masa corporal (IMC), estableciendo como obesidad un valor mayor o igual al percentil 95 y el sobrepeso un valor mayor o igual al percentil 85 y menor al 95 de acuerdo con la edad y sexo, tomando en cuenta la medición de circunferencia de cintura se determinó obesidad abdominal mayor o igual al percentil 90 de acuerdo con la edad y sexo; el porcentaje de grasa corporal de determino por la ecuación de slaughter. Las variables con prevalencias más altas resultaron las del estado nutricional, con donde el 19,1% de la población estudiada presentó sobrepeso y 25,1% obesidad. La prevalencia combinada de sobrepeso y obesidad en niños fue de 51,3% mientras que en niñas 37,4%. Los resultados encontrados en estos niños muestran claramente altas prevalencias de sobrepeso y obesidad. Inclusive más altas al promedio de los niños mexicanos. Concluyendo que en esta escuela es necesario tomar medidas, como poner en marcha programas de actividad física y nutrición orientados a frenar el problema del sobrepeso y obesidad.
Revista chilena de infectología, 2009
Assessment of the Amplicor PCR® for the detection of Mycobacterium tuberculosis in smear negative... more Assessment of the Amplicor PCR® for the detection of Mycobacterium tuberculosis in smear negative respiratory and non respiratory specimens: A retrospective analysis Background: Commercial polymerase chain reaction (PCR) kits are widely accepted for analysis of smear positive respiratory specimens, but the sensitivity is variable for smear negative ones. Objective: To assess the PCR method usefulness in smear negative respiratory and non respiratory specimens. Methods: We compared the PCR results (AMPLICOR MTB test™, Roche) of 235 specimens subjected to culture in Loewenstein-Jensen agar (as the gold standard). Results: 181 (76%) were respiratory and 54 (24%) extra-respiratory specimens. The sensitivity was 88% and 50%, respectively, specificity and PPV was 100% in both cases. NPV was 99.4% in respiratory specimens and 96.1% in non-respiratory specimens. Conclusions: The good performance of this PCR in smear negative respiratory specimens allows the clinician to take decisions based on the result of this exam. In extra-respiratory specimens the contribution is important only when the PCR result is positive.
Revista chilena de infectología, 2013
Surveillance of carbapenem-resistant enterobacteria in stool cultures in a university hospital in... more Surveillance of carbapenem-resistant enterobacteria in stool cultures in a university hospital in Santiago, Chile Background: Clinical cultures detect only one-third of colonized patients with carbapenem-resistant Enterobacteriaceae. Early identification and contact precautions implementation would help to interrupt transmission. In our hospital no carbapenemase-producing enterobacteria infections have been described. Aim: To perform stool surveillance cultures in patients hospitalized in critical care unit with the purpose to detect carbapenemase-producing Enterobacteriacea. Material and Methods: Rectal swabs were obtained of patients after five or more days of hospital stay, on a monthly basis from July to December 2011. Phenotypic assays (modified test Hodge and phenylboronic acid test) and polymerase chain reaction (PCR) searching for six carbapenemases of group A and B of Ambler`s classification were performed. Results: During this period, 241 surveillance rectal cultures were performed. Thirty eight enterobacteria isolated from 30 patients presented a decreased susceptibility to carbapenems by agar dilution method. All PCR were negative. Conclusion: We found that despite the significant number of resistant isolates, patients hospitalized in our institution are not colonized with carbapenemase-producing Enterobacteriaceae. We highlight the importance of screening before having the problem in place.
Virology, 2002
Epidemiologically, certain human papillomaviruses are positively associated with cervical cancer,... more Epidemiologically, certain human papillomaviruses are positively associated with cervical cancer, while adeno-associated viruses (AAV-2) are negatively associated with this same cancer. Both HPV and AAV productively replicate in differentiating keratinocytes of the skin and interact with each other. However, AAV has a relatively fast life cycle, generating infectious progeny by the third to fourth day of an organotypic epithelial raft culture. In contrast, HPV is slow, generating infectious progeny only after 10-12 days. As earlier studies indicated that these two skin-tropic virus types significantly affect each other's life cycle, we investigated if the temporal kinetics of the slow HPV life cycle was affected by the fast AAV in raft cultures. Here it is shown that the presence of AAV-2 at a variety of multiplicities of infection (m.o.i.) resulted in early onset HPV-31b DNA replication. Using plasmids which each expressed only one of the four rep proteins, an enhancement affect was seen for all four rep proteins of AAV, with Rep40 having the highest activity. Furthermore, AAV (m.o.i. of 5) also resulted in a temporally accelerated production of HPV infectious units, seen as early as Day 4, with high levels of viral progeny being produced by Day 6.5. Like earlier studies at Day 12, histological differences were seen at Day 6.5 between AAV-infected and mock-infected HPV/rafts. These data suggest that under specific conditions the AAV rep trans-factors can positively regulate HPV gene expression in addition to the usual negative regulation that has been consistently observed by the rep proteins. These data also suggest that AAV has a significant effect upon the temporal kinetics of the HPV life cycle in natural host tissue. However, it is unclear if or how this AAV-induced fast HPV life cycle mechanistically correlates with lower rates of HPV-associated cervical disease.
Strain, 1999
Orthognatic surgeons have a requirement for the measurement of stress distribution within the hum... more Orthognatic surgeons have a requirement for the measurement of stress distribution within the human lower jaw, in order to aid and improve surgical procedures. Validation of finite element modelling data describing mandible behaviour which has previously been attempted using holographic interferometry. Electronic speckle pattern interferometry (ESPI), a whole field non‐contact optical technique has been applied to the study of a dry human mandible under load. This technique improves over previous methods by generating discrete quantitative displacement and strain components. The optical analysis of a dry mandible is described, with the results viewed in ‘real time’ as progressively greater forces were applied on the lower border of the chin, in the upwards (impact) direction with biting boundary conditions included in the experimental model. This has shown that the bone tissue holding the front teeth transmits the forces impacting on the chin, which are absorbed by the basal bone of the mandible.
Optical Engineering, 1998
A simple and low-cost laser writing system that allows one to obtain micrometer features with hig... more A simple and low-cost laser writing system that allows one to obtain micrometer features with high-quality borders is presented. After an overview of the complete fabrication process of masks to carry out the ion-exchange technique in glass in a selective way, a complete ...
Journal of Modern Optics, 2005
In an effort to find a non-contact technique capable of providing measurements of in-plane strain... more In an effort to find a non-contact technique capable of providing measurements of in-plane strain, the authors designed a speckle shearing interferometer using symmetrical coherent illumination. It is presented the analysis of the sensitivity to displacement and strain of this interferometer, together with the analysis of the phase-stepping of the resultant fringe patterns. A new notation is introduced alongside this analysis to define the interference components in speckle shearing interferometers using multiple illumination beams. Experimental results show the fringe patterns and the phase stepping, in support of the theoretical analysis.
Journal of Modern Optics, 1999
The common digital speckle pattern correlation is a non-contact optical technique which allows th... more The common digital speckle pattern correlation is a non-contact optical technique which allows the measurement of the surface deformation of a test object after it has been exposed to external factors (high temperatures, mechanical stress, humidity, etc.). This technique uses a ...
Journal of Modern Optics, 1997
. A simple, low cost system useful in laser writing processes to set the focal spot on the substr... more . A simple, low cost system useful in laser writing processes to set the focal spot on the substrate surface with micrometre precision is described. Evaluation of its sensitivity is also presented. The lack of essential critical adjustments accounts for the utility of this system and its ...
Journal of Modern Optics, 2006