Absolute electron impact ionization cross-sections for CF4: Three dimensional recoil-ion imaging combined with the relative flow technique.

Here we present measurements of dissociative and non-dissociative cross-sections for the electron impact of the CF4 molecule. The present experiments are based on a Recoil Ion Momentum Spectrometer (RIMS), a standard gas mixing setup for CF4, and a reference gas. The measurements were carried out at several electron energies up to 1 keV, covering the energy range of previous experiments. We apply the relative flow technique (RFT) to convert the relative cross-sections measured by the RIMS into absolute values. Using the combination of RIMS and RFT, ion collection and calibration errors were minimized. The results were compared with theoretical and experimental studies available in the literature. Previous electron impact experiments present relative cross-sections or use correction terms for the absolute cross-sections due to losses of energetic ions. We elucidate the differences between the new measurement method and the existing ones in the literature and explain why the present method can be considered reliable. Furthermore, we show how reducing correction terms affects the results.

Health promoting microbial metabolites produced by gut microbiota after prebiotics metabolism.

Human gut microbiota (HGM) is a microbial complex where dynamic mutualistic interactions related to digestion and absorption of dietary components take place. The consumption of specific food ingredients, such as prebiotics and dietary fibers, constituted mainly by carbohydrates polymers, can modulate the HGM composition and metabolism serving as a fermentable substrate to produce bacterial metabolites with beneficial effects on host health. Especially, bacterial short-chain fatty acids, tryptophan and organic acids have shown positive effects on pathogenic bacteria control, mineral absorption, weight control and obesity, immune response homeostasis, gut barrier improvement, brain modulation and anticancer activity. Despite the fact that these effects vary between individuals due to personal HGM richness, the information presented in this review contributes to understanding the effects of prebiotics and dietary fibers consumption on the generation of HGM metabolites and the mechanisms by which these metabolites interact with host cells improving host health.

Interconnected porosity analysis by 3D X-ray microtomography and mechanical behavior of biomimetic organic-inorganic composite materials.

Hydroxyapatite-based materials have been used for dental and biomedical applications. They are commonly studied due to their favorable response presented when used for replacement of bone tissue. Those materials should be porous enough to allow cell penetration, internal tissue growth, vascular incursion and nutrient supply. Furthermore, their morphology should be designed to guide the growth of new bone tissue in anatomically applicable ways. In this work, the mechanical performance and 3D X-ray microtomography (X-ray µCT) study of a biomimetic, organic-inorganic composite material, based on hydroxyapatite, with physicochemical, structural, morphological and mechanical properties very similar to those of natural bone tissue is reported. Ceramic pieces in different shapes and several porous sizes were produced using a Modified Gel Casting Method. Pieces with a controlled and 3D hierarchical interconnected porous structure were molded by adding polymethylmethacrylate microspheres. Subsequently, they were subject to a thermal treatment to remove polymers and to promote a sinterization of the ceramic particles, obtaining a HAp scaffold with controlled porosity. Then, two different organic phases were used to generate an organic-inorganic composite material, so gelatin and collagen, which was extracted from bovine tail, were used. The biomimetic organic-inorganic composite material was characterized by Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, X-ray Diffraction, Fourier Transform Infrared Spectroscopy and 3D X-ray microtomography techniques. Mechanical properties were characterized in compression tests, obtaining a dramatic and synergic increment in the mechanical properties due to the chemical and physical interactions between the two phases and to the open-cell cellular behavior of the final composite material; the maximum compressive strength obtained corresponds to about 3 times higher than that reported for natural cancellous bone. The pore size distribution obtained could be capable to allow cell penetration, internal tissue in-growth, vascular incursion and nutrient supply and this material has tremendous potential for use as a replacement of bone tissue or in the manufacture and molding of prosthesis with desired shapes.

Complicaciones quirúrgicas de la ascaridiasis en la infancia / Surgical complications of childhood ascariasis

Introducción: La infestación por áscaris consttuye un problema de salud pública importante en áreas endémicas, provocando en algunos casos complicacionesque requieren la intervención del cirujano. El propósito del presente estudio es analizar las complicaciones quirúrgicas de la ascaridiasis,en nuestro medio.Diseño, lugar y partcipantes: se realizó un estudio descriptvo retrospectvo de los pacientes que presentaron complicaciones quirúrgicas debido a lainfestación por A. lumbricoides de enero de 1999 a marzo de 2015 que fueron tratados en la unidad de cirugía pediátrica del hospital general San Juande Dios.Resultados: Ingresaron 47 pacientes con infestación por áscaris, comprendidos en las edades de 1 a 13 años. Hubo 39 pacientes con obstrucción intestnal,7 con ascaridiasis en el colédoco y 1 con apendicits por áscaris. El diagnóstco de los 39 pacientes con oclusión intestnal por áscaris fue clínicoy con rayos X simple de abdomen, 19 resolvieron con tratamiento médico y 20 requirieron de tratamiento quirúrgico. Los pacientes con áscaris en elcolédoco fueron diagnostcados por USG a 1 se le logró extraer el áscaris por CPRE mientras que a los 6 restantes fue necesario la exploración de la víabiliar por laparotomía. El diagnóstco de la apendicits secundario a la obstrucción por áscaris se realizó trans operatoriamente. La morbilidad observadafue del 21% (10/47) de los pacientes: 8 presentaron respuesta infamatoria sistémica y 2 dehisencias de la anastomosis intestnal. La mortalidadfue del 2% (1/47): un paciente con fallo orgánico múltple por sepsis abdominal y desnutrición.Conclusiones: en este estudio, las complicaciones de la infestación por áscaris fueron la obstrucción intestnal, obstrucción de la vía biliar y apendicits...

Introducton: In endemic areas, ascariasis is an important public health problem. In cases of severe infestaton, some cases need to be surgically treated.The aim of this study is to analyze surgical complicatons of childhood ascariasis in our insttuton.Design, Place and Partcipants: A retrospectve study of all patents with ascariasis, from 1999 to 2015, evaluated in the surgical pediatric unit at SanJuan de Dios General Hospital.Results: We analyzed 47 patents with ascariasis, age range 1 to 13 years old. There were 39 patents with intestnal obstructon due to ascariasis, 7 withcholedochal ascariasis and 1 with appendiceal ascariasis. Diagnosis of intestnal obstructon due to ascariasis was made with clinical evaluaton andplain abdominal radiography. Of the 39 patents with abdominal obstructon, 19 resolved with medical treatment and 20 required surgical interventon.Patents with choledochal ascariasis were diagnosed by ultrasonography. In one patent, extracton of the worm was possible with endoscopic retrogradecholangiopancreatography, in the remaining 6 patents, open common bile duct exploraton was required. Diagnosis of the appendiceal ascariasiswas made during appendectomy without previous clinical suspicion. Serious morbidity was 21% (10/47): 8 patents with severe infammatory responseand 2 anastomosis dehiscences. Mortality was 2% (1/47), a patent with multple organ failure, abdominal sepsis and malnourishment. Morbidity andmortality occurred only in patents with intestnal obstructon due to ascariasis. Conclusions: In this study, complicatons of ascariasis were intestnal obstructon, choledochal obstructon and acute appendicits...

Hemangiolinfangioma cerebral. reporte de caso / Orbital limphangioma. case report

El tratamiento del linfangioma orbitario es desafante. El sildenafl se ha propuesto como una opción terapéutca para pacientes con linfangiomas orbitariosirresecables.Se reporta el caso de una paciente de 10 años de edad quien presenta extrusión parcial del globo ocular derecho de curso progresivo rápido, asociado apérdida parcial de la visión, limitación de la movilidad y resistencia a la retropulsión del globo ocular ipsilateral diagnostcado como hemangiolinfangiomacerebral quirúrgicamente irresecable. Se inicia tratamiento con sildenafl a 40mg/día durante 12 semanas, basado en los datos de un estudio pilotorealizado en la Universidad de Stanford; evidenciando regresión marcada del proceso con mejoría clínica, estétca y radiológica.En el presente caso, el tratamiento tras 12 semanas con sildenafl disminuyó el crecimiento de la malformación linfátca. Se requieren estudios conmayor número de pacientes para determinar la efcacia de este tratamiento.

Treatment of orbital lymphangioma can be challenging. Sildenafl has been proposed as a therapeutc opton in patents with unresectable orbitallymphangiomas.We report a 10 year old patent with rapid partal extrusion of the right ocular globe associated with visual impairment whose orbital lymphangiomatreated with 40 mg of sildenafl improved afer 12 weeks.In this case report, treatment with sildenafl for 12 weeks improved surgically irresectable orbital lymphangioma. Larger clinical trials are needed toestablish efcacy of this treatment.

Uso de Sistema de terapia al vacío en cierre de gastrosquisis complicada: reporte de caso / Vacuum-assisted device in gastroschisis

La gastrosquisis constituye una patología grave neonatal que plantea un reto para el cirujano y es una emergencia quirúrgica. En la mayoría de casos, el cierre de la fascia en los casos de gastrosquisis puede realizarse primariamente o después de colocar una bolsa de Silo. Presentamos el caso de unpaciente masculino de 34 semanas por Ballard con gastrosquisis; a quien se le coloco bolsa estéril (Silo) al nacer y presentó dehiscencia parcial de lamisma y evisceración, en seis ocasiones durante un período de tres semanas. Por lo que se colocó sistema de terapia al vació sobre bolsa de plástico estéril fenestrada, realizando tres cambios y logrando el cierre completo del defecto a los 17 días. El sistema de terapia al vacío puede utilizarse comouna alternativa cuando la bolsa de Silo no puede cerrar el defecto abdominal en pacientes con gastrosquisis.

Gastroschisis is a serious neonatal pathology and a surgical emergency. A general procedure for closure of the abdominal wall defect is by primary closureor by placing a protectve ¨silo¨. We report the case of male neonate born at 34 gestatonal weeks with gastroschisis. A Silo bag was placed at birth butpresented dehiscence and partal abdominal evisceraton six tmes during a three week period. A vacuum-assisted device was used over a fenestratedsilo. Three vacuum changes were performed achieving complete closure of the abdominal wall defect in 17 days. The use of vacuum-assisted device isan alternatve when closure of the abdominal wall defect of gastroschisis cannot be achieved with the use of a silo.

Esforços para conservação da espécie Myrmecophaga tridactyla Linnaeus, 1758: tecnologias aplicadas à reprodução / Efforts for the conservation of the Myrmecophaga tridactyla species, Linnaeus, 1758: technologies applied to reproduction

Esforços para conservação do Myrmecophaga tridactyla têm sido realizados. Esta espécie sofre com adestruição de seu habitat natural, incêndios, atropelamentos nas rodovias, entre outros. A presente revisãoapresenta os esforços envidados na conservação do tamanduá-bandeira, com ênfase nas tecnologias aplicadas àreprodução.(AU)

Efforts for the conservation of the Myrmecophaga tridactyla have been done. This species suffers withthe destruction of their natural habitat, fire, road kill on highways, among others. The present review shows theefforts of conservation of the giant anteater, with emphasis on technologies applied to reproduction.(AU)

Esforços para conservação da espécie Myrmecophaga tridactyla Linnaeus, 1758: tecnologias aplicadas à reprodução / Efforts for the conservation of the Myrmecophaga tridactyla species, Linnaeus, 1758: technologies applied to reproduction

Esforços para conservação do Myrmecophaga tridactyla têm sido realizados. Esta espécie sofre com adestruição de seu habitat natural, incêndios, atropelamentos nas rodovias, entre outros. A presente revisãoapresenta os esforços envidados na conservação do tamanduá-bandeira, com ênfase nas tecnologias aplicadas àreprodução.

Efforts for the conservation of the Myrmecophaga tridactyla have been done. This species suffers withthe destruction of their natural habitat, fire, road kill on highways, among others. The present review shows theefforts of conservation of the giant anteater, with emphasis on technologies applied to reproduction.

Methods for equine preantral follicles isolation: quantitative aspects.

The aim of this study was to test the use of mechanical and mechanical-enzymatic methods, saline solution (SS), and PBS solution for the manipulation and isolation of mare ovarian preantral follicles (PAFs). The ovaries were subjected to mechanical isolation (mixer) alone or in association with enzymatic digestion (collagenase). Incubation times of 10 and 20 min were employed. In the first group, 4.1 ± 4.9 PAFs were harvested with the mechanical-enzymatic method vs 71.1 ± 19.2 with the mechanical procedure, showing a significant difference between methods; using SS and PBS, these numbers were 35.7 ± 34.3 and 39.6 ± 39.6, respectively, with no significant difference between solutions. In the second group, there was significant difference between methods, with 7.1 ± 10.6 follicles harvested with the mechanical-enzymatic method vs 63.2 ± 22.9 with the mechanical procedure; using SS and PBS, means were 35.5 ± 36.4 and 34.9 ± 31.1, respectively. The mechanical method proved more effective than the mechanical-enzymatic approach. Both SS and PBS can be used as a media for equine PAFs preparation.

Degradation of a model azo dye in submerged anaerobic membrane bioreactor (SAMBR) operated with powdered activated carbon (PAC).

This work investigated the anaerobic degradation of the model azo dye Remazol Yellow Gold RNL in an upflow anaerobic sludge blanket reactor (UASB) and two submerged anaerobic membrane (SAMBR) bioreactors, one of which (SAMBR-1) was operated with powdered activated carbon (PAC) in its interior. The reactors were operated at 35 °C with a hydraulic retention time of 24 h in three operational phases, aimed to assess the effect of external sources of carbon (glucose) or redox mediator (yeast extract) on the removal or color and organic matter. The results showed that removal efficiencies of COD (73-94%) and color (90-94%) were higher for SAMBR-1 when compared to SAMBR-2 (operated without PAC) and UASB reactors. In addition, the presence of PAC in SAMBR-1 increased reactor stability, thereby leading to a lower accumulation of volatile fatty acids (VFA). The microfiltration membrane was responsible for an additional removal of ~50% of soluble residual COD in the form of VFA, thus improving permeate quality. On its turn, PAC exhibited the ability to adsorb byproducts (aromatic amines) of azo dye degradation as well as to act as source of immobilized redox mediator (quinone groups on its surface), thereby enhancing color removal.

Embryonic and larval development of Eugerres mexicanus (Perciformes: Gerreidae) in Tenosique: Tabasco, Mexico

Most studies on Eugerres mexicanus mainly consider biogeographic and systematic aspects and rarely address reproductive characteristics, which are useful for fishery population management plans. This study aimed at evaluating the ontogeny of E. mexicanus, based on 30 embryos and 30 larvae sampled by induced spawning of breeders, taken in February 2009 from the Usumacinta River in Tenosique, Tabasco, Mexico. All descriptions of the embryonic development were based on morphometric and meristic data and followed standard methods. Eggs, recovered at the gastrula stage, had an average diameter of 1.17mm (SD=0.08). The bud stage appeared during the first three hours of development, in which the posterior side was adhered to the vitellus; Kupffer´s vesicle was visible. Yolk-sac larvae hatched 18 hours after fertilization, exhibiting a light brown color and an average total length of 2.94mm (SD=0.70); the preflexion stage was reached eight days after hatching, with a total average length of 4.67mm (SD=0.50) and a total notochord length of 4.45mm (SD=0.50). The flexion stage was reached on the 16th day, with an average total length of 6.66mm (SD=1.53), while postflexion was reached on the 24th day, with 10.33mm (SD=1.45). The pre-juvenile stage was reached on the 33rd day, with a total length of 14.30mm (SD=0.93), showing IX spines and 10 rays and III spines and eight rays in the dorsal and anal fins, respectively. The juvenile stage was reached by the 45th day, with an average length of 28.16mm (SD=1.93) and average weight of 4.75g (SD=1.49). Prejuveniles showed an initial pigmentation with dark colored dots in the superior and inferior jaw and dispersed on the head, while juveniles presented the same pigmentation pattern, decreasing towards the margin of the caudal peduncle. In conclusion, the embryonic developmental stages of E. mexicanus were typical for the Gerreidae group. However, their morphometric characters were slightly different since the diameter and size of the drop of oil were bigger than those reported for marine species. In addition, regarding pigmentation, the yolk-sac larvae of E. mexicanus were olive and yellow on the margin of the notochord, which differs from those reported for other species. This is the first recorded report on the reproductive biology and early life development of this species.

La ontogenia se basó en 30 embriones y 30 larvas, obtenidos mediante la inducción del desove de reproductores provenientes de la ribera del río Usumacinta en Tenosique, Tabasco, México, recolectados en febrero de 2009. La descripción se fundamentó en el registro morfométrico y merístico. Los huevos fueron recuperados en estado de gástrula y presentaron un diámetro de promedio de 1.17mm (SD=0.08). Durante las primeras tres horas de desarrollo embrionario, se presentó la etapa de capullo, en la que se observó la región caudal adherida al vitelo, apreciándose la vesícula de Kupffer. Las larvas con saco eclosionaron a las 18 horas pos-fertilización, fueron de color marrón claro con un promedio de 2.94mm; (SD=0.70) de longitud total y alcanzaron la preflexión a los ocho días post-eclosión con una longitud total promedio de 4.67mm; (SD=0.50) y una longitud total del notocordio de 4.45; (SD=0.50). A los 16 días de la eclosión alcanzaron la flexión, con un promedio de 6.66mm; (SD=1.53) de longitud total. La postflexión se presentó a los 24 días con 10.33mm; (SD=1.45). Al llegar a los 33 días, se presentó la fase prejuvenil y llegaron a medir 14.30; (SD=0.93) de longitud total, presentando IX espinas y 10 radios en la aleta dorsal y III y ocho en la aleta anal. Los juveniles midieron 28.16; (SD=1.93) de longitud a los 45 días, con un peso promedio de 4.75g; (SD=1.49). Los prejuveniles presentaron una pigmentación inicial en la mandíbula superior e inferior con tintes oscuros en forma de puntos y de manera dispersa sobre la cabeza. En los juveniles se observó el mismo patrón de pigmentación, disminuyendo hacia el margen del pedúnculo caudal. Las características descriptivas de la etapa de desarrollo embrionario de E. mexicanus son típicas del período de desarrollo de los peces de la familia Gerreidae, en particular en el caso de las especies E. brasilianus y E. lineatus que habitan en ambientes marinos. Sin embargo, sus caracteres morfométricos son diferentes con respecto al diámetro y el tamaño de los huevos y de la gota de aceite, ya que en E. mexicanus son más grandes que los de las especies marinas y son similares a los de los peces de agua dulce. Con respecto a la pigmentación, la larva con saco de E. mexicanus presenta un olor olivo y amarillo sobre el margen del notocordio, lo cual difiere a lo reportado para E. lineatus,ya que en esta muestra un grupo de melanóforos entre los miomeros nueve al 13 como principal característica, y para Diapturus peruvianus por presentar tres manchas en el margen dorsal de los intestinos desde la inserción de la aleta pectoral hasta el ano. Los resultados de este estudio son los primeros registrados para esta especie y han generado información sobre aspectos de su biología reproductiva y el desarrollo de la vida temprana.

Electron-recoil ion and recoil ion-projectile coincidence techniques applied to obtain absolute partial collision cross sections.

We present in detail an alternative experimental set-up and data analysis, based on the electron-recoil ion and recoil ion-projectile coincidence techniques, that enable the measurement of partial pure ionization and partial charge exchange cross sections for an effusive gas jet set-up, where the absolute target density and recoil ion efficiency cannot be measured directly. The method is applied to the ionization of helium atoms due to collision with partially stripped C(3 +) projectiles. In order to check the method, the results are compared to data available in the literature where the target density and recoil ion detection efficiency were measured directly. The pure ionization channel is compared to the electron capture channel.

Citogenética clássica aplicada ao monitoramento de germoplasma bovino / Classic cytogenetic applied to the monitoring of bovine germplasm

Com a evolução das biotecnologias da reprodução, o avanço dos programas de melhoramento genético animal e a necessidade de conservação de raças em risco de extinção, o monitoramento do material genético bovino é de fundamental importância. Entre os meios de monitoramento de germoplasmas, a citogenética constitui uma das ferramentas acessíveis para grande parte dos laboratórios ligados à reprodução animal. O presente trabalho busca mostrar a relevância da citogenética no monitoramento de germoplasma bovino.(AU)

With the evolution of reproduction technologies, advancement of animal breeding programs and the need for conservation of breeds in dangers of extinction, the monitoring of bovine genetic material is fundamental importance. Among the means to monitor these germplasms, the cytogenetic constitutes one of tools available for most laboratories engaged in animal reproduction. The present work shows the relevance of cytogenetics in the monitoring of bovine germplasm.(AU)

Citogenética clássica aplicada ao monitoramento de germoplasma bovino / Classic cytogenetic applied to the monitoring of bovine germplasm

Com a evolução das biotecnologias da reprodução, o avanço dos programas de melhoramento genético animal e a necessidade de conservação de raças em risco de extinção, o monitoramento do material genético bovino é de fundamental importância. Entre os meios de monitoramento de germoplasmas, a citogenética constitui uma das ferramentas acessíveis para grande parte dos laboratórios ligados à reprodução animal. O presente trabalho busca mostrar a relevância da citogenética no monitoramento de germoplasma bovino.

With the evolution of reproduction technologies, advancement of animal breeding programs and the need for conservation of breeds in dangers of extinction, the monitoring of bovine genetic material is fundamental importance. Among the means to monitor these germplasms, the cytogenetic constitutes one of tools available for most laboratories engaged in animal reproduction. The present work shows the relevance of cytogenetics in the monitoring of bovine germplasm.

Water fragmentation and energy loss by carbon ions at the distal region of the Bragg peak.

Time-of-flight mass spectrometry was used to investigate fragmentation and energy transfer processes in water by C ions at the distal part of the Bragg peak. Measurements of the positive ion fragments from ionization, electron capture, electron loss, transfer-loss and loss-ionization channels have allowed us for the first time (a) to obtain a quantitative determination of the energy lost by C ions in water and (b) to show that total water fragment ion production has a much flatter profile with projectile energy than would be expected if the water radical formation was assumed to follow the energy-loss profile obtained from available stopping power models.

Fragmentation of water by heavy ions.

Absolute cross sections for fragmentation of water molecules by C3+ and O5+ ions over an energy region where the Bragg peak maximizes were measured for ionization, electron capture, and electron loss channels. A collision regime where sigmaSigmaOq+> or =sigmaH2O+ was reached for the first time, producing large abundances of H+ and O+ fragments in comparison to proton impact. Our findings have straightforward implications in the subsequent fast chemistry at the ionization site and on the O production in the first stages of water radiolysis. An unexpected channel-independent relationship between the cross sections for the fragmentation products, which is also approximately independent of the particle type, energy, and charge state, is found. A model is presented to explain such behavior allowing the cross sections of all fragmentation products to be obtained from single and double electron removal cross sections.

Chromosomal aberration analysis in workers exposed to chemical and biological hazards in research laboratories.

Cytogenetic monitoring of individuals occupationally exposed to chemical and biological hazards has found increased frequencies of cells with chromosomal aberrations. During the present study we analyzed the frequency of chromosomal aberrations in cells from individuals working in various chemistry and biology research laboratories of the University of Brasilia, Brazil. When evaluated jointly and compared to a control group there was no significant increase in the frequency of chromosomal aberrations in the laboratory personnel. However, a group constituted of individuals of the Genetics Laboratory showed a statistically significant increase in the frequency of structural chromosomal aberrations of the chromatid gap type.

Influência da vitrificação na incidência de ovócitos bovinos aneuplóides maturados in vitro.

O presente estudo objetivou verificar a incidência de aneuploidias em ovócitos bovinos vitrificados em diferentes períodos de maturação. Os ovócitos foram obtidos de ovários de abatedouro e divididos em cinco grupos: controle (ovócitos não vitrificados); grupos 0-h (vitrificados antes do começo da maturação); e grupos 8, 12 e 22-h (vitrificados respectivamente 8, 12 e 22 h após o começo da maturação). Os ovócitos permaneceram vitrificados por 24 h e então foram descongelados e completaram 24 horas de maturação. Em seguida os ovócitos foram desnudados, fixados em lâmina e corados com orceína-acética. Nenhuma diferença foi encontrado (P > 0,05) entre o grupo controle (6,2%, 1/16 ) e grupos 0, (22,0, 2/9) 8 h (22,0, 2/9), 12 (25,0%, 3/12), 22 h (23,5%, 4/17). Os resultados sugerem que a vitrificação em diferentes períodos de maturação não influencia na taxa de aneuploidia.

Influência da vitrificação na incidência de ovócitos bovinos aneuplóides maturados in vitro.

O presente estudo objetivou verificar a incidência de aneuploidias em ovócitos bovinos vitrificados em diferentes períodos de maturação. Os ovócitos foram obtidos de ovários de abatedouro e divididos em cinco grupos: controle (ovócitos não vitrificados); grupos 0-h (vitrificados antes do começo da maturação); e grupos 8, 12 e 22-h (vitrificados respectivamente 8, 12 e 22 h após o começo da maturação). Os ovócitos permaneceram vitrificados por 24 h e então foram descongelados e completaram 24 horas de maturação. Em seguida os ovócitos foram desnudados, fixados em lâmina e corados com orceína-acética. Nenhuma diferença foi encontrado (P > 0,05) entre o grupo controle (6,2%, 1/16 ) e grupos 0, (22,0, 2/9) 8 h (22,0, 2/9), 12 (25,0%, 3/12), 22 h (23,5%, 4/17). Os resultados sugerem que a vitrificação em diferentes períodos de maturação não influencia na taxa de aneuploidia.

Evaluación comparativa del método automatizado BACTEC MGIT 960 con el método de las proporciones para determinar susceptibilidad a drogas antituberculosas en Chile / Comparative evaluation of automated BACTEC MGIT 960 for testing susceptibility of Mycobacterium tuberculosis to antituberculous drugs in Chile

The automated BACTEC MGIT 960 system was compared with the method of proportion (MP) for testing susceptibility of Mycobacterium tuberculosis to antituberculous drugs. 275 strains of M. tuberculosis isolated in Chile from 270 patients between 2001 and 2003 were tested. Concordance of BACTEC MGIT 960 with MP depending on the antituberculous drug tested was the following: 97.0% for streptomycin, 98,9% for rifampicin, 97,4% for isoniazid and 98,1% for ethambutol. Total resistance to antituberculous drugs of the 275 strains of M. tuberculosis tested varied from 20.4 % assessed by MP to 25.1% evaluated by BACTEC MGIT 960. These differences were not significant (p: ns; t test). BACTEC MGIT 960 yielded 17 strains as resistant. These same 17 strains were detected as sensitives by MP. Therefore, BACTED MGIT overestimates the number of resistant strains. In our study BACTEC MGIT 960 showed a very good concordance with MP and besides it allowed to get the results in a much shorter period of time than MP. Additional analysis are needed to know the factors envolved in BACTED MGIT overestimation of resistant strains.

Se comparó el método automatizado BACTEC MGIT 960 con el método de las proporciones (MP) para la determinación de la susceptibilidad a drogas anti tuberculosas de 275 cepas de Mycobacterium tuberculosis aisladas de 270 pacientes en Chile entre 2001 y 2003. La concordancia del BACTEC MGIT 960 con el MP según las drogas estudiadas fue de: 97,0% para estreptomicina, 98,9% para rifampicina, 97,4% para isoniazida y 98,1% para etambutol. Los porcentajes globales de resistencia a drogas anti-TBC de las 275 cepas de M. tuberculosis estudiadas, determinados por el BACTEC MGIT960 y el MP fueron de 25,1% y 20,4% respectivamente. Esta diferencia no fue estadísticamente significativa. El BACTEC MGIT 960 dió como resistentes 17 cepas que fueron sensibles por el MP, sobrestimándose por este método la información de cepas resistentes. El BACTEC MGIT 960 en nuestra experiencia presentó una muy buena concordancia con el MP permitiendo un notable acortamiento en el tiempo de obtención de los resultados. Sin embargo, la mayor determinación de cepas resistentes por parte de este método requiere de nuevos análisis que permitan conocer los factores que inciden en este fenómeno.