Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Heliyon ; 10(10): e31309, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38831820

RESUMEN

In the study of photocatalytic and photoactivated processes and devices a tight control on the illumination conditions is mandatory. The practical challenges in the determination of the necessary photonic quantities pose serious difficulties in the characterization of catalytic performance and reactor designs and configurations, compromising an effective comparison between different experiments. To overcome these limitations, we have designed and constructed a new illumination system based in the concept of the integrating sphere (IS). The system provides uniform and isotropic illumination on the sample, either in batch or continuous flow modes, being these characteristics independent of the sample geometry. It allows direct, non-contact and real time determination of the photonic quantities as well as versatile control on the irradiance values and its spectral characteristics. It can be also scaled up to admit samples of different sizes without affecting its operational behaviour. The performance of the IS system has been determined in comparison with a second illumination system, mounted on an optical bench, that provides quasi-parallel beam (QPB) nearly uniform illumination in tightly controlled conditions. System performance is studied using three sample geometries: a standard quartz cuvette, a thin straight tube and a microreactor by means of potassium ferrioxalate actinometry. Results indicate that the illumination geometry and the angular distribution of the incoming light greatly affect the absorption at the sample. The sample light absorption efficiency can be obtained with statistical uncertainties of about 3% and in very good agreement with theoretical estimations.

2.
Vaccines (Basel) ; 12(3)2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38543960

RESUMEN

Few data are available on antibody response for some SARS-CoV-2 vaccines, and there is a lack of ability to compare vaccine responses in the same population. This cross-sectional study conducted in Nicaragua examines the SARS-CoV-2 antibody responses in individuals, previously exposed to high infection rates who have received various vaccines. The vaccines under comparison include well-known ones like Pfizer (BNT162b2) and AstraZeneca (ChAdOx1-S), alongside less-studied vaccines including Soberana (Soberana 02), Abdala (CIGB-66), and Sputnik V/Sputnik Light. Overall, 3195 individuals participated, with 2862 vaccinated and 333 unvaccinated. We found that 95% of the unvaccinated were seropositive, with much lower titers than the vaccinated. Among the vaccinated, we found that Soberana recipients mounted the highest anti-spike response (mean difference (MD) = 36,498.8 [20,312.2, 52,685.5]), followed by Abdala (MD = 25,889.9 [10,884.1, 40,895.7]), BNT162b2 (MD = 12,967.2 [7543.7, 18,390.8]) and Sputnik with AstraZeneca as the reference group, adjusting for age, sex, vaccine status, days after last dose, and self-reported COVID-19. In addition, we found that subjects with complete vaccination series had higher antibody magnitude than those with incomplete series. Overall, we found no evidence of waning in the antibody magnitude across vaccines. Our study supports the conclusion that populations with high infection rates still benefit substantially from vaccination.

3.
Waste Biomass Valorization ; 12(12): 6423-6432, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34093901

RESUMEN

The purpose of this study is to investigate how to recycle FFP2 face masks used during Covid-19 pandemic without using previous sorting process and to characterize the properties of the material obtained. The way of splitting and processing the mixture of materials was studied as well as the final properties such as chemical, thermal and mechanical characteristics. The resulting recycled material is a blend of polymers with such mechanical and thermal properties that could be used as an alternative to recycled PP (polypropylene). Avoidance of previous sorting process gives the face mask recycling a new and simplified way of preventing this material to be disposed in environment and an opportunity of second life for the polymers they are made of. With this work we lay the basis to reduce the plastic pollution related with the recommended use of face masks during Covid-19 pandemic.

4.
Mycoses ; 64(11): 1396-1401, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33966300

RESUMEN

OBJECTIVES: Histoplasmosis and cryptococcosis are important public health problems in people living with HIV (PLHIV) in Central America. Conventional laboratory assays, based on microscopy and culture, are not optimal for the diagnosis of either disease. However, antigen (Ag) assays are rapid and highly accurate for the diagnosis of these infections. METHODS: Laboratory surveillance of PLHIV was carried out in four hospitals in Panama, Honduras and Nicaragua, between 2015 and 2019. Detection of Histoplasma antigens in urine was performed by enzyme immunoassay (EIA), and Cryptococcus antigen detection in sera and cerebrospinal fluid specimens was performed by lateral flow assay (LFA). RESULTS: A total of 4,453 PLHIV with clinical suspicion of histoplasmosis (n = 1,343) or cryptococcosis (n = 3,110; 2,721 sera and 389 CSF) were tested. Of 1,343 patients suspected of having histoplasmosis, 269 (20%) were Histoplasma Ag positive. Of 3,110 patients tested using the Cryptococcus Ag assay, 329 (11%) were positive. Honduras reported the highest positivity rates (32% for Histoplasma Ag, and 16% for Cryptococcus Ag); Panama reported the largest number of patients testing positive using the Histoplasma Ag assay (n = 201); and Nicaragua reported the largest number of patients testing positive using the Cryptococcus Ag assay (n = 170). CONCLUSION: Here, we show how the implementation of rapid diagnostics assays impacted case detection and was useful for the care of people with advanced HIV. Rapid and accurate diagnosis could reduce mortality associated with histoplasmosis and cryptococcosis in PLHIV.


Asunto(s)
Criptococosis/diagnóstico , Infecciones por VIH/complicaciones , Histoplasmosis/diagnóstico , Adulto , Antígenos Fúngicos/sangre , Antígenos Fúngicos/líquido cefalorraquídeo , Antígenos Fúngicos/orina , Cryptococcus/inmunología , Femenino , Citometría de Flujo , Histoplasma/inmunología , Honduras , Humanos , Técnicas para Inmunoenzimas , Masculino , Nicaragua , Panamá
5.
J Laparoendosc Adv Surg Tech A ; 31(3): 261-265, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33325786

RESUMEN

Background: During the Health Emergency due to coronavirus disease 2019 (COVID-19) in Peru, elective surgeries were suspended and only emergency surgeries were allowed. Conservative management was considered as an alternative and laparoscopic surgery was indicated following safety recommendations. Surgically operated patients were at higher risk of becoming infected with COVID-19 due to hospital exposure, being more susceptible to complications. Methods: Retrospective cohort-type analytical study that includes patients who were admitted to a private center due to an emergency and who underwent laparoscopic gastrointestinal surgery during the National Health Emergency (group exposed to the COVID-19 pandemic) from March 11, 2020 to June 8, 2020 and were compared with those patients operated between March 11, 2019 and June 8, 2019 (group not exposed to the COVID-19 pandemic). Results: A total of 104 patients were identified, 59 patients operated during the COVID-19 pandemic. All were operated by laparoscopy, both groups with a similar degree of disease severity. There was no mortality or surgical reintervention. No surgeon at the institution was infected with the virus during the study period. Conclusions: The degree of severity of abdominal surgical pathologies in this time of pandemic has not increased compared with the previous year. Likewise, the laparoscopic approach to emergency surgery was safe and effective during the pandemic.


Asunto(s)
COVID-19/epidemiología , Enfermedades del Sistema Digestivo/cirugía , Urgencias Médicas , Servicio de Urgencia en Hospital/estadística & datos numéricos , Laparoscopía/estadística & datos numéricos , Pandemias , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Comorbilidad , Enfermedades del Sistema Digestivo/epidemiología , Procedimientos Quirúrgicos Electivos/estadística & datos numéricos , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Perú/epidemiología , Estudios Retrospectivos , SARS-CoV-2 , Adulto Joven
6.
Actual. psicol. (Impr.) ; 32(124): 16-33, ene.-jun. 2018.
Artículo en Español | LILACS, INDEXPSI, SaludCR | ID: biblio-1088553

RESUMEN

Resumen Este artículo validó la Escala de Perfeccionismo Infantil (EPI) de Oros en una población infantil peruana. Se contó con la participación de 1084 niños con edades comprendidas entre los 7 y 12 años (M = 9.75; DE = 1.23) de siete instituciones educativas, privadas y públicas. El Análisis Factorial Exploratorio reveló una escala bidimensional oblicua (Reacción ante el fracaso y Autodemandas); no obstante, tres ítems tuvieron una carga < .30. El Análisis Factorial Confirmatorio corroboró la estructura bidimensional oblicua con la salvedad de errores correlacionados. La fiabilidad fue estimada mediante el coeficiente Omega (ω = .810). Se concluye que la EPI cuenta con evidencia de validez y fiabilidad de las puntuaciones.


Abstract This article discusses the validation of the Oros' Child Perfectionism Scale (EPI) in a Peruvian child population. A total of 1084 children aged 7 to 12 years (M = 9.75, SD = 1.23) from seven private and public educational institutions participated. Exploratory Factor Analysis revealed an oblique two-dimensional scale (Reaction to failure and Self-orders); however, three items had a load <. 30. The Confirmatory Factor Analysis corroborated the bidimensional oblique structure with the exception of correlated errors. Reliability was estimated using the Omega coefficient (ω = .810). It is concluded that the EPI has evidence of validity and reliability of the scores.


Asunto(s)
Humanos , Masculino , Femenino , Niño , Pruebas de Personalidad , Conducta , Perfeccionismo
7.
Radiat Prot Dosimetry ; 176(4): 450-455, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28369635

RESUMEN

This paper presents the results of the first characterization and experimental measurements of scatter dose at cardiologist's eyes for the only X-ray system that performs all paediatric Interventional cardiology procedures in Costa Rica. Entrance surface air kerma (ESAK) and the scatter dose values were measured on phantoms of 4-20 cm thicknesses of polymethyl methacrylate slabs. Image quality was evaluated using DICOM images of a test object Leeds TOR 18-FG, through the numerical parameters signal-to-noise ratio (SNR), high-contrast spatial resolution (HCSR) and figure of merit (FOM). When PMMA thickness is increased and during a move from low fluoroscopy to cine modes, ESAK, SNR, HCSR and FOM values range from 0.44 to 391.0 µGy fr-1; 2.8 to 14.89; 3.17 to 15.54 and 0.51 to 79.94, respectively. The highest scattered dose rates recorded during the simulations were 1.79 and 8.04 mSv h-1 for the high fluoroscopy and cine modes, respectively.


Asunto(s)
Cardiología , Ojo/efectos de la radiación , Exposición Profesional/análisis , Radiografía Intervencional , Radiometría/métodos , Niño , Angiografía Coronaria , Costa Rica , Fluoroscopía , Humanos , Fantasmas de Imagen , Polimetil Metacrilato , Dispersión de Radiación , Relación Señal-Ruido
8.
Influenza Other Respir Viruses ; 10(4): 340-5, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26946216

RESUMEN

OBJECTIVES: Our objective was to estimate the incidence of influenza-associated hospitalizations and in-hospital deaths in Central American Region. DESIGN AND SETTING: We used hospital discharge records, influenza surveillance virology data, and population projections collected from Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua to estimate influenza-associated hospitalizations and in-hospital deaths. We performed a meta-analysis of influenza-associated hospitalizations and in-hospital deaths. MAIN OUTCOME MEASURES: The highest annual incidence was observed among children aged <5 years (136 influenza-associated hospitalizations per 100 000 persons). RESULTS: Annually, 7 625-11 289 influenza-associated hospitalizations and 352-594 deaths occurred in the subregion. CONCLUSIONS: Our results suggest that a substantive number of persons are annually hospitalized because of influenza. Health officials should estimate how many illnesses could be averted through increased influenza vaccination.


Asunto(s)
Hospitalización/economía , Gripe Humana/economía , Gripe Humana/mortalidad , Adolescente , Adulto , América Central/epidemiología , Niño , Preescolar , Humanos , Lactante , Gripe Humana/epidemiología , Gripe Humana/terapia , Masculino , Persona de Mediana Edad , Adulto Joven
9.
Int J Environ Res Public Health ; 11(8): 8301-18, 2014 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-25153463

RESUMEN

Leptospirosis is an epidemic-prone zoonotic disease that occurs worldwide, with more than 500,000 human cases reported annually. It is influenced by environmental and socioeconomic factors that affect the occurrence of outbreaks and the incidence of the disease. Critical areas and potential drivers for leptospirosis outbreaks have been identified in Nicaragua, where several conditions converge and create an appropriate scenario for the development of leptospirosis. The objectives of this study were to explore possible socioeconomic variables related to leptospirosis critical areas and to construct and validate a vulnerability index based on municipal socioeconomic indicators. Municipalities with lower socioeconomic status (greater unsatisfied basic needs for quality of the household and for sanitary services, and higher extreme poverty and illiteracy rates) were identified with the highest leptospirosis rates. The municipalities with highest local vulnerability index should be the priority for intervention. A distinction between risk given by environmental factors and vulnerability to risk given by socioeconomic conditions was shown as important, which also applies to the "causes of outbreaks" and "causes of cases".


Asunto(s)
Brotes de Enfermedades , Leptospirosis/epidemiología , Humanos , Nicaragua/epidemiología , Factores Socioeconómicos
10.
Appl Spectrosc ; 68(5): 549-56, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25014598

RESUMEN

Spectroscopic and morphological studies, designed to improve our understanding of the physicochemical phenomena that occur during zircon crystallization, are presented. The zircon fission track method (ZFTM) is used routinely in various laboratories around the world; however, there are some methodological difficulties needing attention. Depending on the surface fission track density observed under an optical microscope, the zircon grain surfaces are classified as homogeneous, heterogeneous, hybrid, or anomalous. In this study, zircon grain surfaces are characterized using complementary techniques such as optical microscopy (OM), micro-Raman spectroscopy, and scanning electron microscopy (SEM), both before and after chemical etching. Our results suggest that anomalous grains have subfamilies and that etching anisotropy related to heterogeneous grains is due to different crystallographic faces within the same polished surface that cannot be observed under an optical microscope. The improved methodology was used to determine the zircon fission track ages of samples collected from the Bauru Group located in the north of Paraná Basin, Brazil. A total of 514 zircon grains were analyzed, consisting of 10% homogeneous, about 10% heterogeneous, about 20% hybrid, and 60% anomalous grains. These results show that the age distributions obtained for homogeneous, heterogeneous, and hybrid grains are both statistically and geologically compatible.

11.
Artículo en Inglés | MEDLINE | ID: mdl-25834763

RESUMEN

OBJECTIVE: To evaluate the impact of the implementation of a guideline for the management of personality disorders on reducing the frequency of use of mechanical restraints in a psychiatric inpatient unit. METHOD: This retrospective study was conducted in a psychiatric inpatient unit with 42 beds, which serves an urban area of 330,000 inhabitants. The sample consisted of all patients with a clinical diagnosis of personality disorder (DSM-IV-TR criteria) who were admitted to the unit from January 2010 to December 2010 and from January 2011 to December 2011 (ie, before and after, respectively, the implementation of the guideline). The guideline focused on cluster B disorders and follows a psychodynamic perspective. RESULTS: Restraint use was reduced from 38 of 87 patients with personality disorders (43.7%) to 3 of 112 (2.7%), for a relative risk of 0.06 (95% CI, 0.02-0.19) and an absolute risk reduction of 41% (95% CI, 29.9%-51.6%). The risk of being discharged against medical advice increased after the intervention, with a relative risk of 1.84 (95% CI, 0.96-3.51). Restraint use in patients with other diagnoses was also reduced to a similar extent. CONCLUSIONS: The use of mechanical restraints was dramatically reduced after the implementation of a clinical practice guideline on personality disorders, suggesting that these coercive measures might be decreased in psychiatric inpatient units.

12.
Appl Spectrosc ; 67(4): 404-8, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23601540

RESUMEN

Characterization by micro-Raman spectroscopy of polymeric materials used as nuclear track detectors reveals physico-chemical and morphological information on the material's molecular structure. In this work, the nuclear track detector poly(allyl diglycol carbonate), or Columbia Resin 39 (CR-39), was characterized according to the fluence of alpha particles produced by a (226)Ra source and chemical etching time. Therefore, damage of the CR-39 chemical structure due to the alpha-particle interaction with the detector was analyzed at the molecular level. It was observed that the ionization and molecular excitation of the CR-39 after the irradiation process entail cleavage of chemical bonds and formation of latent track. In addition, after the chemical etching, there is also loss of polymer structure, leading to the decrease of the group density C-O-C (∼888 cm(-1)), CH=CH (∼960 cm(-1)), C-O (∼1110 cm(-1)), C-O-C (∼1240 cm(-1)), C-O (∼1290 cm(-1)), C=O (∼1741 cm(-1)), -CH2- (∼2910 cm(-1)), and the main band -CH2- (∼2950 cm(-1)). The analyses performed after irradiation and chemical etching led to a better understanding of the CR-39 molecular structure and better comprehension of the process of the formation of the track, which is related to chemical etching kinetics.

13.
Int J Environ Res Public Health ; 9(11): 3883-910, 2012 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-23202822

RESUMEN

Leptospirosis is an epidemic-prone zoonotic disease that occurs worldwide. In Central America, leptospirosis outbreaks have been reported in almost all countries; Nicaragua in particular has faced several outbreaks. The objective of this study was to stratify the risk and identify "critical areas" for leptospirosis outbreaks in Nicaragua, and to perform an exploratory analysis of potential "drivers". This ecological study includes the entire country (153 municipalities). Cases from 2004 to 2010 were obtained from the country's health information system, demographic and socioeconomic variables from its Census, and environmental data from external sources. Criteria for risk stratification of leptospirosis were defined. Nicaragua reported 1,980 cases of leptospirosis during this period, with the highest percentage of cases (26.36%) in León, followed by Chinandega (15.35%). Among the 153 municipalities, 48 were considered critical areas, 85 were endemic and 20 silent. Using spatial and statistical analysis, the variable presenting the most evident pattern of association with critical areas defined by top quintile of incidence rate is the percentage of municipal surface occupied by the soil combination of cambisol (over pyroclastic and lava bedrock) and andosol (over a volcanic ashes foundation). Precipitation and percentage of rural population are also associated with critical areas. This methodology and findings could be used for Nicaragua's Leptospirosis Intersectoral Plan, and to identify possible risk areas in other countries with similar drivers.


Asunto(s)
Brotes de Enfermedades , Leptospirosis/epidemiología , Técnicas de Planificación , Humanos , Nicaragua/epidemiología , Factores de Riesgo
14.
Appl Spectrosc ; 66(5): 545-51, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22524960

RESUMEN

Studies of zircon grains using optical microscopy, micro-Raman spectroscopy, and scanning electron microscopy (SEM) have been carried out to characterize the surface of natural zircon as a function of etching time. According to the surface characteristics observed using an optical microscope after etching, the zircon grains were classified as: (i) homogeneous; (ii) anomalous, and (iii) hybrid. Micro-Raman results showed that, as etching time increases, the crystal lattice is slightly altered for homogeneous grains, it is completely damaged for anomalous grains, and it is altered in some areas for hybrid grains. The SEM (energy dispersive X-ray spectroscopy, EDS) results indicated that, independent of the grain types, where the crystallinity remains after etching, the chemical composition of zircon is approximately 33% SiO(2):65% ZrO(2) (standard natural zircon), and for areas where the grain does not have a crystalline structure, there are variations of ZrO(2) and, mainly, SiO(2). In addition, it is possible to observe a uniform surface density of fission tracks in grain areas where the determined crystal lattice and chemical composition are those of zircon. Regarding hybrid grains, we discuss whether the areas slightly altered by the chemical etching can be analyzed by the fission track method (FTM) or not. Results of zircon fission track and U-Pb dating show that hybrid and homogeneous grains can be used for dating, and not only homogeneous grains. More than 50 sedimentary samples from the Bauru Basin (southeast Brazil) were analyzed and show that only a small amount of grains are homogeneous (10%), questioning the validity of the rest of the grains for thermo-chronological evolution studies using zircon FTM dating.

16.
Acta Ortop Mex ; 23(2): 74-9, 2009.
Artículo en Español | MEDLINE | ID: mdl-19432362

RESUMEN

Autologous nerve grafting is the most referred technique for bridging neural gaps. The aim of this study was to evaluate the effects of distally sliding the epineurial sheath to cover a defect created in the left sciatic nerve of the rat. Twenty male Wistar rats were divided into three groups: sham (n=6), in which the sciatic nerve was dissected but left intact; conventional suture (CS, n=7), in which a transverse section of the sciatic nerve was followed by an epineurial suture; sliding of the distal epineurial sheath (SDES, n=7), in which a 5 mm resection of the nerve was conducted, followed by a circumferential cut in the distal epineurium, and the epineurial sheath was slid down and sutured into the distal end of the epineurium of the proximal stump. After 12 weeks, histomorphometric analyses of the number of myelinated nerve fibers, mean cross-sectional axonal area and total fiber diameter (G-ratio) were carried out. There was no statistical differences between CS and SDES (p > 0.05, ANOVA). However, an increase in the number of myelinated nerve fibres (p < 0.001, ANOVA) and decreases in the mean axonal area (p < 0.001, ANOVA) and in the G-ratio were observed in SDES or SC groups when compared to sham, although with no statistical differences between the SDES and SC. It could be suggested this technique is efficient to cover nerve gaps in rats.


Asunto(s)
Nervio Ciático/cirugía , Animales , Masculino , Ratones , Regeneración Nerviosa , Procedimientos Neuroquirúrgicos/métodos
17.
J Med Microbiol ; 57(Pt 10): 1303-1305, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18809564

RESUMEN

We describe what we believe to be the first case of neonatal sepsis caused by CTX-M-producing Escherichia coli, in a low-weight preterm infant, born to a colonized mother who had received antibiotic treatment antepartum. Increased dissemination of extended-spectrum beta-lactamase-producing E. coli in the community should be borne in mind for empirical therapy of sepsis in high-risk newborns.


Asunto(s)
Infecciones por Escherichia coli/microbiología , Escherichia coli/enzimología , Enfermedades del Prematuro/microbiología , Sepsis/microbiología , beta-Lactamasas/metabolismo , Antibacterianos/uso terapéutico , Infecciones por Escherichia coli/transmisión , Femenino , Humanos , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Masculino , Meropenem , Embarazo , Complicaciones Infecciosas del Embarazo/microbiología , Tienamicinas/uso terapéutico
18.
Acta Biochim Pol ; 54(2): 387-99, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17565386

RESUMEN

N-Acetylmannosamine (ManNAc) is the first committed intermediate in sialic acid metabolism. Thus, the mechanisms that control intracellular ManNAc levels are important regulators of sialic acid production. In prokaryotic organisms, UDP-N-acetylglucosamine (GlcNAc) 2-epimerase and GlcNAc-6-P 2-epimerase are two enzymes capable of generating ManNAc from UDP-GlcNAc and GlcNAc-6-P, respectively. We have purified for the first time native GlcNAc-6-P 2-epimerase from bacterial source to apparent homogeneity (1 200 fold) using Butyl-agarose, DEAE-FPLC and Mannose-6-P-agarose chromatography. By SDS/PAGE the pure enzyme showed a molecular mass of 38.4 +/- 0.2 kDa. The maximum activity was achieved at pH 7.8 and 37 degrees C. Under these conditions, the K(m) calculated for GlcNAc-6-P was 1.5 mM. The 2-epimerase activity was activated by Na(+) and inhibited by mannose-6-P but not mannose-1-P. Genetic analysis revealed high homology with bacterial isomerases. GlcNAc-6-P 2-epimerase from E. coli K92 is a ManNAc-inducible protein and is detected from the early logarithmic phase of growth. Our results indicate that, unlike UDP-GlcNAc 2-epimerase, which promotes the biosynthesis of sialic acid, GlcNAc-6-P 2-epimerase plays a catabolic role. When E. coli grows using ManNAc as a carbon source, this enzyme converts the intracellular ManNAc-6-P generated into GlcNAc-6-P, diverting the metabolic flux of ManNAc to GlcNAc.


Asunto(s)
Carbohidrato Epimerasas/aislamiento & purificación , Carbohidrato Epimerasas/metabolismo , Escherichia coli/enzimología , Secuencia de Aminoácidos , Bacterias/enzimología , Bacterias/genética , Secuencia de Bases , Carbohidrato Epimerasas/química , Carbohidrato Epimerasas/genética , Cationes/farmacología , ADN Bacteriano/genética , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Hexosaminas/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Datos de Secuencia Molecular , Peso Molecular , Ácido N-Acetilneuramínico/metabolismo , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/aislamiento & purificación , Homología de Secuencia de Aminoácido , Especificidad por Sustrato
19.
Rev. argent. urol. (1990) ; 71(2): 113-120, abr.-jun. 2006. ilus, tab
Artículo en Español | LILACS | ID: lil-438779

RESUMEN

Objetivos: Mostrar luego de 13 años de experiencia contínua, los resultados en lo que a continencia y micción se refiere de la neovejiga colónica derecha, como así también los fundamentos fisiológicos y urodinámicos de los mismos. Materiales y Métodos: Entre febrero de 1993 y marzo de 2006 a 43 pacientes cistectomizados, por presentar cáncer de vejiga, se les reconstruyo el tracto urinario inferior utilizando un reservorio construido con colon derecho destubulizado y reconfigurado y ciego intacto. A todos los pacientes se les realizo cistografías al retirar el catéter uretral, a 32 estudios urodinámicos y a 5 videourodinámicos. Resultados: Cuarenta y un pacientes (95,4 porciento) orinan con un flujo máximo de más de 25 ml/seg. La continencia diurna y nocturna fue completa e inmediata en el 97 porciento y 93 porciento respectivamente, un paciente requiere cateterismo intermitente, otro permanece incontinente y los dos restantes lograron continencia nocturna satisfactoria. Se define como continencia completa e inmediata al control de la orina sin necesidad de usar paño protector desde el momento en que se retira el catéter uretral, satisfactoria al uso de no mas de un pañal por día y micción espontánea y efectiva a la evacuación del reservorio con un flujo medio de 10 ml/seg. sin residuo postmiccional. Conclusión: Los resultados con esta nueva neovejiga colónica derecha, en lo que a continencia y micción se refiere, son significativamente superiores a los logrados con otros procedimientos descriptos en la literatura


Asunto(s)
Neoplasias de la Vejiga Urinaria
20.
J Urol ; 174(5): 1882-6, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16217329

RESUMEN

PURPOSE: We report the long-term functional results of the colonic neobladder and provide the physiological and urodynamic foundations for them. MATERIALS AND METHODS: From March 1993 to February 2004, 38 patients with cystectomy received a neobladder constructed from detubularized, remodeled right colon and intact cecum following our design at the urology service at our institution. Most patients underwent urodynamics and videourodynamics as postoperative followup. We defined total continence as not using any protection whatsoever (neither pads nor a night alarm), which was immediate upon removing the urethral catheter. RESULTS: A total of 37 patients achieved total daytime continence immediately and the remaining 1 was totally continent after 30 days (100%). Nighttime continence was total and immediate in 36 patients (92%) and satisfactory in 2. Micturition was immediate, satisfactory and total in 37 patients with an average maximum flow of more than 26 ml per second. The patient who did not achieve micturition required clean intermittent catheterization. Videourodynamic studies revealed that continence resulted from the low pressure developed in the large capacity reservoir (more than 600 ml) and from intact intestine haustral contractions, which ejected urine toward the detubularized and remodeled area. In turn, micturition was attained through a combination of abdominal wall tension and mass contractions of the nondetubularized segment, which generated a pressure of more than 100 cm. CONCLUSIONS: The functional results of this new neobladder are significantly greater than those achieved with other procedures already described in the literature because of the different way in which it functions.


Asunto(s)
Colon Sigmoide/trasplante , Cistectomía/métodos , Neoplasias de la Vejiga Urinaria/cirugía , Micción/fisiología , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Recuperación de la Función , Estudios Retrospectivos , Medición de Riesgo , Sensibilidad y Especificidad , Factores de Tiempo , Neoplasias de la Vejiga Urinaria/patología , Reservorios Urinarios Continentes , Urodinámica/fisiología , Grabación en Video
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...