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1.
J Appl Microbiol ; 126(2): 523-533, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30276936

RESUMEN

AIMS: The objective of this work was to isolate and characterize indigenous rhizobia from coal-mining areas able to efficiently nodulate and fix nitrogen in association with Calopogonium mucunoides (calopo). METHODS AND RESULTS: Isolation, authentication and morphological, biochemical and molecular characterization of the autochthonous rhizobia were performed and their symbiotic efficiency (SE) evaluated. Efficient rhizobial isolates suitable for the inoculation of calopo in coal-mining regions were obtained. A total of 30 isolates were obtained after nodulation authentication, of which five presented high SE with plant-growth promoting traits such as indole-3-acetic acid production, phosphate solubilization and biofilm formation. These isolates were identified as belonging to Bradyrhizobium, Pseudomonas and Rhizobium. CONCLUSIONS: Bradyrhizobium sp. A2-10 and Pseudomonas sp. A6-05 were able to promote calopo plant growth using soil obtained from coal-mining degraded areas, thus indicating their potential as inoculants aiming at land reclamation. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report of Pseudomonas nodule formation in calopo. Furthermore, the results demonstrated that autochthonous rhizobia obtained from degraded soils presented high SE in calopo and possess a wide range of plant-growth promoting traits. Ultimately, they may all contribute to an increased leguminous plant growth under stress conditions. The selected rhizobia strains may be used as inoculants and present a valuable role in the development of strategies aiming to recover coal-mining degraded areas. Bacterial inoculants would greatly reduce the use of often harmful nitrogen fertilizers vastly employed in revegetation programmes of degraded areas.


Asunto(s)
Bradyrhizobium/fisiología , Minas de Carbón , Restauración y Remediación Ambiental , Fabaceae/crecimiento & desarrollo , Pseudomonas/fisiología , Bradyrhizobium/aislamiento & purificación , Bradyrhizobium/metabolismo , Fabaceae/metabolismo , Fabaceae/microbiología , Fabaceae/fisiología , Nodulación de la Raíz de la Planta , Pseudomonas/aislamiento & purificación , Pseudomonas/metabolismo , Rhizobium/aislamiento & purificación , Rhizobium/metabolismo , Rhizobium/fisiología , Suelo , Simbiosis
2.
Lett Appl Microbiol ; 68(6): 497-504, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30924177

RESUMEN

The coal reserves in the south of Brazil were intensely exploited at the time of great demand for such fuel. This resulted in changes in the environment, mainly in the chemical, physical and biological characteristics of the soil. Due to the potential to control erosive processes, increase soil quality and restore biological diversity, revegetation is a promising alternative to recover those impacted areas. In that respect, bracatinga is a pioneering tree species that easily grow in different environments and has being planted as vegetation cover in areas under recovery. Therefore, the objective of this work was to characterize the chemical features and to evaluate the soil microbiological attributes in areas degraded by coal mining and under recovery using bracatinga as cover plant. In the bracatinga canopy projection area, soil samples were collected in the environmental restoration areas that have been, at the time of collecting, under a regime of 2, 4, 6 and 12 years of restoration. In addition an area with natural occurrence of bracatinga was used as control. Microbial biomass nitrogen, microbial biomass carbon and microbial biomass respiration increase in average 281, 230 and 157% respectively, when the 12-year-old areas were compared to the 2-year-old-areas. Likewise, a decrease in qCO2 in the order of 60% was observed for that same comparison. The 12-year-old areas reached the same values of qCO2 found in the reference area. The data suggest an improvement in the microbiological attributes of the soil with the increase in recovery time for the studied areas. SIGNIFICANCE AND IMPACT OF THE STUDY: In coal mining areas under recovery with typically acid soils, the use of the current recovery strategies (revegetation mainly) has been efficient to increase the quality of soils, especially in the environmental restoration areas. Soil microbiological attributes such as microbial biomass nitrogen, microbial biomass carbon, microbial basal respiration and metabolic quotient (qCO2 ) are dynamic and highly sensitive. These parameters have the potential to be adopted together with conventional attributes, such as floristic composition indices and species diversity indices, to evaluate the degree of any particular environmental recovery process being conducted at previously explored mining areas.


Asunto(s)
Minas de Carbón/métodos , Restauración y Remediación Ambiental/métodos , Mimosa/crecimiento & desarrollo , Mimosa/metabolismo , Microbiología del Suelo , Suelo/química , Biodiversidad , Biomasa , Brasil , Carbono/análisis , Carbón Mineral/análisis , Nitrógeno/análisis , Árboles
3.
Bull Environ Contam Toxicol ; 103(4): 515-520, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31143976

RESUMEN

Concentration of essential (Se, Zn and Cu) and non-essential (As, Cd, Hg and Pb) trace elements were measured in selected tissues of two dead whale sharks (Rhincodon typus) stranded in the Gulf of California (GC) in 2017 and 2018. Concentrations of Cd and Pb in the skeletal muscle of the whale shark from La Paz Bay, GC were higher compared to a previous study on whale shark from China. The shark from La Paz Bay also presented higher concentration of Pb in the epidermis, compared to the same tissue of the other whale shark stranded in Punta Bufeo, GC. The Hg in all analysed tissues was lower than those documented in carnivorous sharks. Molar ratio Se:Hg shows an excess of Se over Hg in all the tissues sampled in both sharks.


Asunto(s)
Monitoreo del Ambiente/métodos , Epidermis/química , Metales Pesados/análisis , Músculo Esquelético/química , Tiburones/metabolismo , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Bahías/química , México , Océano Pacífico
4.
Genet Mol Res ; 11(3): 2559-68, 2012 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-22869076

RESUMEN

The causal agent of witches' broom disease, Moniliophthora perniciosa is a hemibiotrophic and endemic fungus of the Amazon basin and the most important cocoa disease in Brazil. The purpose of this study was to analyze the genetic diversity of polysporic isolates of M. perniciosa to evaluate the adaptation of the pathogen from different Brazilian regions and its association with different hosts. Polysporic isolates obtained previously in potato dextrose agar cultures of M. perniciosa from different Brazilian states and different hosts (Theobroma cacao, Solanum cernuum, S. paniculatum, S. lycocarpum, Solanum sp, and others) were analyzed by somatic compatibility grouping where the mycelium interactions were distinguished after 4-8 weeks of confrontation between the different isolates of M. perniciosa based on the precipitation line in the transition zone and by protein electrophoresis through SDS-PAGE. The diversity of polysporic isolates of M. perniciosa was grouped according to geographic proximity and respective hosts. The great genetic diversity of M. perniciosa strains from different Brazilian states and hosts favored adaptation in unusual environments and dissemination at long distances generating new biotypes.


Asunto(s)
Agaricales/genética , Agaricales/aislamiento & purificación , Variación Genética , Esporas Fúngicas/genética , Agaricales/fisiología , Brasil , Cacao/microbiología , Filogenia
5.
Phys Chem Chem Phys ; 13(4): 1506-14, 2011 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-21109872

RESUMEN

The electronic structure and the optical response of free catechol, [Ti(cat)(3)](2-) complex, and catechol bound to TiO(2) nanoclusters have been analysed using time dependent density functional theory (TD-DFT) performing calculations both in real time and frequency domains. Both approaches lead to similar results providing the basis sets and functionals are similar. For all cases, the simulated spectra agree well with the experimental ones. For the adsorption systems, the spectra show a band at 4.7 eV associated to intramolecular catechol π→π* transitions, and low energy bands corresponding to transitions from catechol to the cluster with a tail that is red-shifted when the coupling between the dye and the cluster is more effective. Thus, dissociative adsorption modes provide longer tails than the molecular mode. Although the bidentate complex is more stable than the monodentate, the energy difference between both is smaller when the cluster size increases. Small cluster models reproduce the main features of the optical response, however, the (TiO(2))(15) cluster constitutes the minimal size to provide a complete picture. In this case, the conventional TD-DFT (frequency domain) calculations are highly demanding computationally, while real time TD-DFT is more efficient and the calculations become affordable.

6.
Acta Psychiatr Scand ; 119(2): 117-27, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19016667

RESUMEN

OBJECTIVE: Variation in the serotonin transporter gene (SLC6A4) promoter region has been shown to influence depression in persons who have been exposed to a number of stressful life events. METHOD: We evaluated whether genetic variation in 5-HTTLPR, influences current depression, lifetime history of depression and quantitative measures of depression in persons with chronic psychotic disorders. This is an association study of a genetic variant with quantitative and categorical definitions of depression conducted in the southwest US, Mexico and Costa Rica. We analyzed 260 subjects with a history of psychosis, from a sample of 129 families. RESULTS: We found that persons carrying at least one short allele had a statistically significant increased lifetime risk for depressive syndromes (P < 0.02, odds ratio 2.18, 95% CI 1.10-4.20). CONCLUSION: The 'ss' or 'sl' genotype at the 5-HTTLPR promoter polymorphic locus increases the risk of psychotic individuals to develop major depression during the course of their illness.


Asunto(s)
Trastorno Depresivo/genética , Polimorfismo Genético/genética , Trastornos Psicóticos/genética , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Adulto , Alelos , Enfermedad Crónica , Comorbilidad , Costa Rica/epidemiología , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/epidemiología , Femenino , Predisposición Genética a la Enfermedad/epidemiología , Predisposición Genética a la Enfermedad/genética , Humanos , Masculino , México/epidemiología , Oportunidad Relativa , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/epidemiología , Factores de Riesgo , Índice de Severidad de la Enfermedad , Tiempo , Estados Unidos/epidemiología
7.
ACS Appl Mater Interfaces ; 10(19): 16911-16917, 2018 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-29671568

RESUMEN

The separation and purification of light hydrocarbons is challenging in the industry. Recently, a ZJNU-30 metal-organic framework (MOF) has been found to have the potential for adsorption-based separation of olefins and diolefins with four carbon atoms [H. M. Liu et al. Chem.-Eur. J. 2016, 22, 14988-14997]. Our study corroborates this finding but reveals Fe-MOF-74 as a more efficient candidate for the separation because of the open metal sites. We performed adsorption-based separation, transient breakthrough curves, and density functional theory calculations. This combination of techniques provides an extensive understanding of the studied system. Using this MOF, we propose a separation scheme to obtain a high-purity product.

8.
An Pediatr (Barc) ; 65(5): 415-27, 2006 Nov.
Artículo en Español | MEDLINE | ID: mdl-17184601

RESUMEN

INTRODUCTION: Spanish medical faculties have initiated the new curriculum reform process within the framework of the European Higher Education Area and are required to incorporate the European Credit Transfer System (ECTS) to new syllabi before 2010. OBJECTIVES: To test the introduction of the ECTS in pediatrics and modify the teaching methodology. STUDY DESIGN: The theoretical and practical programs were adapted; academic objectives and a student evaluation system were established. Students were surveyed on starting the second term of the 2004-05 academic year before the theory examination and again on terminating the academic year: a 5-point Likert-type scale was used for responses. Priorities for generic and specific competencies selected by students were compared with those selected by the National Deans Conference (NDC). The results were analyzed using non-parametric tests. RESULTS: Fifteen credits became 11 ECTS, with 297 student working hours. The theory program was reduced from 80 to 52 lessons. The students prepared 14 tutor-supervised case presentations. The teaching staff considered that learning of theory was similar to previous years (66 %) and that practical learning improved (73.3 %). The students thought the program should continue (73.2 %) but 98.8 % considered the workload excessive. The students believed that their practical training and their ability to prepare and make case presentations significantly improved during the semester. Academic performance was significantly higher than that in students of the previous year. Students agreed with NDC priorities for 9/9 general and 4/17 specific competencies. Estimation of workload by students was significantly higher than that by staff, and 73.3 % of the students believed that workload should be reduced and the examination system improved. CONCLUSIONS: Introducing the ECTS improved academic performance, practical training, and self-directed learning. The project was satisfactory for staff and students. Student workload was underestimated.


Asunto(s)
Educación Médica/normas , Cooperación Internacional , Pediatría/educación , Desarrollo de Programa , Enseñanza/métodos , Enseñanza/normas , Logro , Curriculum/normas , Europa (Continente)
9.
Braz J Biol ; 75(4): 894-905, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26628223

RESUMEN

Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC), organic (OC) and integrated management systems containing intercropping of Brachiaria decumbens (IB) or Arachis pintoi (IA) were sampled. Total organic carbon (TOC), microbial biomass carbon (MBC) and nitrogen (MBN), microbial activity (C-CO2), metabolic quotient (qCO2), the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF) colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils) method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.


Asunto(s)
Agricultura/métodos , Biodiversidad , Café/crecimiento & desarrollo , Invertebrados/fisiología , Microbiología del Suelo , Animales , Biomasa , Brasil , Carbono/análisis , Ambiente , Suelo
10.
J Nucl Med ; 24(9): 799-802, 1983 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6310070

RESUMEN

Three leukemic patients showing minimal bone uptake of Tc-99m pyrophosphate but with good uptake of methylene diphosphonate are described.


Asunto(s)
Huesos/metabolismo , Difosfatos/metabolismo , Difosfonatos/metabolismo , Leucemia/diagnóstico por imagen , Tecnecio/metabolismo , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cintigrafía , Medronato de Tecnecio Tc 99m , Pirofosfato de Tecnecio Tc 99m
11.
J Nucl Med ; 21(5): 413-6, 1980 May.
Artículo en Inglés | MEDLINE | ID: mdl-7373410

RESUMEN

We report our initial clinical experience with a simplified spleen-imaging technique that requires no red cell washing or special kits. Thirty minutes after an injection of "cold" pyrophosphate containing 0.5 mg of stannous chloride or fluoride, a blood sample is drawn, 2 mCl of pertechnetate (Tc-99m) are added, the sample is incubated at 49--50 degrees for 35 min, and then reinjected into the patient. We have studied 13 patients with this technique, and have found it useful in the clarification of various questionable splenic abnormalities found on the sulfur colloid scan, as well as in the detection of splenosis.


Asunto(s)
Eritrocitos , Bazo/diagnóstico por imagen , Tecnecio , Adulto , Anciano , Niño , Coristoma/diagnóstico por imagen , Femenino , Humanos , Recién Nacido , Marcaje Isotópico , Masculino , Cintigrafía , Enfermedades del Bazo/diagnóstico por imagen
12.
Semin Nucl Med ; 15(3): 260-75, 1985 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-3898380

RESUMEN

While 99mTc sulfur colloid imaging, because of its availability and convenience, remains the initial procedure of choice for spleen imaging, selective spleen scanning with damaged 99mTc-labeled RBCs can provide additional information in some cases. These cases include overlapping left hepatic lobe and suspected splenic pathology but with poor radiocolloid uptake that precludes visualization. Other indications are detection of residual splenic tissue after splenectomy, suspected asplenia, polysplenia, and situs ambiguus. The selective 99mTc-denatured RBC scan is most useful to confirm or exclude defects seen on the radiocolloid study and to detect small amounts of splenic tissue.


Asunto(s)
Eritrocitos , Bazo/diagnóstico por imagen , Enfermedades del Bazo/diagnóstico por imagen , Azufre Coloidal Tecnecio Tc 99m , Tecnecio , Adulto , Niño , Femenino , Hematoma/diagnóstico por imagen , Humanos , Hiperesplenismo/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Cintigrafía , Bazo/anomalías , Esplenectomía
13.
Br J Ophthalmol ; 83(9): 1002-5, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10460764

RESUMEN

AIM: To investigate the influence of several clinical variables on the development of visual field loss in the "second eye" of patients with normal tension glaucoma (NTG) presenting with unilateral field loss. METHODS: Patients with NTG and unilateral field loss at presentation were selected from a cohort of 403 consecutive diagnoses of NTG. The state of the visual field "normal" or with a visual field defect was defined using the Advanced Glaucoma Intervention Study (AGIS) template. Where available, optic disc planimetry was carried out on stereo photographs taken at presentation. Measurements of the topography of each of these optic discs were compared with morphometric values from a group of normal subjects, allowing for differences in age and disc size. For each patient the percentage of the relative neuroretinal rim (NRR) area was calculated. The time taken to develop a visual field defect was related to clinical factors including age, sex, peak and mean diurnal intraocular pressure (IOP), refraction, relative NRR area, and the AGIS score of the fellow eye at presentation RESULTS: 54 patients were included in the study. The median (range) follow up time was 49.2 (11.1-116.7) months. 14 (26%) patients developed field loss in the eyes with an initially normal field. The estimate of the median time to field loss onset was 95.1 months. Field damage developed more rapidly in women and in patients with greater AGIS score in the contralateral eye at the beginning of follow up ((adjusted hazard ratio, HR (95% confidence interval, CI) 0.20 (0. 04; 0.93); 1.19 (1.02; 1.41) respectively)). Little evidence of any association was found between time to onset of field loss and each of age, refraction, and peak or mean diurnal IOP. Planimetric disc analysis was carried out in 33 (61%) patients. Of these 10 (30%) developed field loss in the eyes with initial normal field at a median follow up of 95.1 months. After adjustment for sex and AGIS, relative NRR area was found to be significantly related to the time of onset of field damage, the greater the reduction in relative NRR area, the shorter the time to visual field loss (HR 0.93 (0.89; 0. 99)). CONCLUSIONS: NTG patients with unilateral field loss are at high risk of developing field damage in the eyes with an initially normal visual field. In this study, the visual prognosis of the eye with the normal visual field at presentation was found to be influenced by the extent of the reduction in relative NRR area together with the severity of field damage in the contralateral eye at presentation.


Asunto(s)
Glaucoma de Ángulo Abierto/fisiopatología , Trastornos de la Visión/fisiopatología , Femenino , Estudios de Seguimiento , Glaucoma de Ángulo Abierto/patología , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Disco Óptico , Fotograbar , Pronóstico , Análisis de Regresión , Estudios Retrospectivos , Análisis de Supervivencia , Trastornos de la Visión/patología , Campos Visuales/fisiología
14.
J Chromatogr A ; 881(1-2): 531-41, 2000 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-10905733

RESUMEN

Changes of the polyamines (PAs) titer in high- and mid-molecular-mass carbohydrates (HMMCs and MMMCs, respectively) obtained from sugarcane juices stored for 72 h at pH 5.2 or clarified at pH 8.0 have been studied. Cadaverine (CAD) is the most abundant free (S) PA in the MMMC fraction from juices at pH 5.2, whereas putrescine (PUT) was revealed as the main PA at pH 8.0. A slight increase in the free PUT titer can be noted at pH 5.2 for 72 h of juice starvation. PAs from MMMC were mainly conjugated to acid-insoluble (PH) molecules. Accumulation of PH-PAs with the time of starvation was especially significant for PUT and CAD. However, CAD has also been detected in the acid-soluble (SH) fraction and its concentration increases with the time of starvation at pH 5.2. The accumulation pattern of free and conjugated PAs from HMMCs is similar to that found for MMMCs although some differences can be observed. For instance, the increase in free PUT with the time at pH 8.0 was 2.7-times higher in the HMMC fraction than in the MMMC fraction. Conjugated PAs associated to acid-soluble macromolecules (SH fraction) achieved a level in HMMC fractions higher than that observed in the MMMC fraction. Moreover, the reported increase with time that was observed in PH-CAD from the MMMC fraction was not observed in the HMMC fraction, and, finally, the increase in PH-PUT with the time was lower for the HMMC fraction than for the MMMC fraction.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Plantas/química , Poliaminas/química
15.
J Agric Food Chem ; 47(8): 3086-92, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10552613

RESUMEN

Sugarcane juice contains a lot of sucrose associated with several monosaccharides, defined as low molecular mass carbohydrates (LMMC), as well as some polysaccharides and glycoproteins, which are defined as mid and high molecular mass carbohydrates (MMMC and HMMC, respectively). These three categories of carbohydrates can be separated by size-exclusion chromatography through Sephadex G-10 and Sephadex G-50 columns, but elution profiles change drastically after juice clarification performed by adjusting the pH value of the juice to 8.0. In addition, polyamines and some phenolics are currently associated with carbohydrate preparations, and the distribution pattern of these conjugates also changes after clarification. Polyamine levels generally decrease after juice clarification. Cadaverine is completely removed from the different carbohydrate preparations, whereas spermidine is the main polyamine occurring in association with sugarcane carbohydrates, as free or acid-soluble form in LMMC preparation or as acid-soluble and -insoluble forms in both MMMC and HMMC preparations. Polyamines, presumably spermidine, conjugate to p-hydroxybenzoic acid in LMMC, mostly to caffeic acid in MMMC, and to syringic acid in HMMC preparations. HMMC-associated polyamines appear in both acid-soluble and -insoluble fractions. Syringic acid also occurs in the LMMC preparation, but juice clarification changes it from acid-soluble to free form, and it coelutes with sucrose.


Asunto(s)
Fenoles/química , Extractos Vegetales/química , Plantas Comestibles/química , Poliaminas/análisis , Sacarosa , Manipulación de Alimentos , Concentración de Iones de Hidrógeno
16.
Theriogenology ; 39(5): 1173-85, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-16727285

RESUMEN

One-cell embryos from mice and rabbits were microinjected with a hybrid gene composed of 1.6 kilobases (kb) promoter/regulatory sequences of the bovine alphaS1 casein gene fused to the complementary DNA (cDNA) encoding for the human tissue plasminogen activator (htPA) and 3'untranslated sequences from rabbit beta-globin and SV 40 genes. Transgenic mice and rabbits that carry the htPA gene were obtained. In mice, 11 founder females were generated, and 6 of them expressed low levels (about 50 mug/ml) of htPA in their milk. Some of the transgenic mice showed rearrangements of the microinjected DNA sequences as judged by Southern blot analysis. A position-dependent expression of the transgene is suspected to occur. The only live-born founder transgenic rabbit obtained was a male, and it transmitted the transgene in a Mendelian fashion to F1 females, which expressed htPA at very low levels (8 to 50 ng/ml). Although the 1.6-kb bovine alphaS1 casein promoter that was used directs the synthesis of htPA specifically to the mammary gland, it may not be sufficient for a high level of expression.

17.
Theriogenology ; 42(6): 977-85, 1994 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-16727602

RESUMEN

This study was designed to determine the possibility of using F1 crossbreed cattle (HolsteinxZebu) as donors of oocytes for in vitro fertilization (IVF) and for pronuclear gene microinjection into in vitro-produced embryos. In the first part of the experiment oocytes from Bos taurus (Holstein), Bos indicus (Zebu) and F1 crossbred Bos taurusxBos indicus (HolsteinxZebu) genotypes were inseminated with Bos taurus (Holstein) semen and were allocated for in vitro embryo production using conventional IVF procedures. No differences were observed on the in vitro maturation (IVM) rates between breeds (HolsteinxHolstein:85%, ZebuxHolstein:84% and ZebuxHolsteinxHolstein:88%). Holstein cows yielded the highest number of cumulus oocyte complexes (6.8 per ovary) for in vitro maturation, differing (P<0.05) from ZebuxHolstein and ZebuxHolsteinxHolstein F1 by 5.1 and 5.8, respectively. However, the Holstein breed also yielded the lowest percentage of cleavage (45.1 vs 71.9% for ZebuxHolstein and 65.1% for ZebuxHolsteinxHolstein). Of the 3 genotypes, the hybrid F1 breed was the most efficient source of oocytes for the production of embryos capable of reaching morulae and blastocyst stages (76/250; P<0.001). In the second part of the study, 599 oocytes from the F1 breed were fertilized in vitro, 1 group of 150 oocytes was used for the determination of the optimal pronuclear visualization period. The highest number of oocytes with 2 pronuclei was observed between 24 to 28 h after IVF (27 to 42%). The remaining 399 oocytes were microinjected with a gene construct bearing the bacterial lacZ gene as the reporter for gene expression. Survival of embryos to microinjection was 73.8%, and 45.5% of them (50/110) cleaved in culture. Of the microinjected embryos, 1 out of 50 showed beta-galactosidase activity. These findings indicate that a tropical crossbreed of cattle (ZebuxHolsteinxHolstein) can be used as a source of oocytes for IVF programs and gene microinjection studies.

18.
Clin Nucl Med ; 17(1): 34-5, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1544259

RESUMEN

Technical error is not usually considered among the many possible causes of false-positive lung scans. A case is presented where the inadvertent injection of Tc-99m MAA through a Swan-Ganz catheter resulted in radionuclide imaging mimicking massive pulmonary embolism. After reinjection in a peripheral vein, a repeat perfusion scan showed unremarkable findings. Lack of the appropriate clinical presentation and the rarity of massive perfusion defects are important clues to recognizing this unusual but misleading situation.


Asunto(s)
Pulmón/diagnóstico por imagen , Embolia Pulmonar/diagnóstico por imagen , Agregado de Albúmina Marcado con Tecnecio Tc 99m , Anciano , Cateterismo de Swan-Ganz , Reacciones Falso Positivas , Humanos , Masculino , Embolia Pulmonar/epidemiología , Cintigrafía , Agregado de Albúmina Marcado con Tecnecio Tc 99m/administración & dosificación , Relación Ventilacion-Perfusión
19.
Clin Nucl Med ; 9(1): 1-3, 1984 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-6697611

RESUMEN

The appearance of gallium-67 images in bone infarction was studied in nine patients with sickle cell disease and correlated with the bone scan findings. Gallium uptake in acute infarction was decreased or absent with a variable bone scan uptake, and normal in healing infarcts, which showed increased uptake on bone scan. The significance of these findings is discussed.


Asunto(s)
Huesos/irrigación sanguínea , Radioisótopos de Galio , Infarto/diagnóstico por imagen , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cintigrafía , Rasgo Drepanocítico/complicaciones , Tibia/irrigación sanguínea
20.
Clin Nucl Med ; 6(1): 19-22, 1981 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7449235

RESUMEN

To determine the accuracy of the posterior cerebral radionuclide angiogram (CRAG) in the detection of carotid occlusive disease, a retrospective study of 186 patients who underwent both CRAG and contrast cerebral angiography within a period of 30 days was carried out. Asymmetry of neck activity was highly specific (97%) but insensitive (27%) for detection of carotid disease. When asymmetry of cerebral perfusion was also considered, the sensitivity rose to 61%, but the specificity fell to 77%. For the entire group, including carotid and intracerebral disease, the sensitivity of the posterior CRAG was 49% and the specificity 89%. From these data and a review of the literature, we conclude that the CRAG is too insensitive to be used as a screening test for carotid occlusive disease.


Asunto(s)
Arteriopatías Oclusivas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Angiografía Cerebral , Lateralidad Funcional , Humanos , Cintigrafía
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