Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Más filtros

País/Región como asunto
Intervalo de año de publicación
1.
Rev Argent Microbiol ; 56(2): 175-186, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38336597

RESUMEN

Peanuts (Arachis hypogaea L.) are among the most important leguminous crops in Argentina. During the growing season, they are frequently attacked by fungal diseases, including Thecaphora frezii. The spores of T. frezii are structures that confer resistance to this phytopathogen. The transition from teliospore to hypha is a characteristic process of some fungi, which is essential for completing their life cycle. Using the transcriptomes of teliospores and hyphae of T. frezii, we aimed to identify genes that were differentially expressed during this transition, and we found 134 up-regulated and 66 down-regulated genes, which would participate in different cellular processes such as: (a) cell cycle and DNA processing; (b) cell fate; (c) rescue, defense and cellular virulence; (d) detoxification by CYP450; (e) energy; (f) nutrient interaction and nutritional adaptation; (g) metabolism; (g) proteins with binding functions or cofactor requirements; (h) stress, cell differentiation and biogenesis of cell components; and (i) transport, cell communication and transcription. The identification of genes in T. frezii and their expression levels during different stages of differentiation could contribute to our understanding of the biological mechanisms in this fungus.


Asunto(s)
Arachis , Hifa , Esporas Fúngicas , Arachis/microbiología , Hifa/genética , Hifa/crecimiento & desarrollo , Esporas Fúngicas/genética , Enfermedades de las Plantas/microbiología , Regulación Fúngica de la Expresión Génica , Genes Fúngicos , Proteínas Fúngicas/genética , Transcriptoma , Perfilación de la Expresión Génica
2.
Ecology ; 99(3): 576-582, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29315513

RESUMEN

Understanding controls on net primary production (NPP) has been a long-standing goal in ecology. Climate is a well-known control on NPP, although the temporal differences among years within a site are often weaker than the spatial pattern of differences across sites. Climate sensitivity functions describe the relationship between an ecological response (e.g., NPP) and both the mean and variance of its climate driver (e.g., aridity index), providing a novel framework for understanding how climate trends in both mean and variance vary with NPP over time. Nonlinearities in these functions predict whether an increase in climate variance will have a positive effect (convex nonlinearity) or negative effect (concave nonlinearity) on NPP. The influence of climate variance may be particularly intense at ecosystem transition zones, if species reach physiological thresholds that create nonlinearities at these ecotones. Long-term data collected at the confluence of three dryland ecosystems in central New Mexico revealed that each ecosystem exhibited a unique climate sensitivity function that was consistent with long-term vegetation change occurring at their ecotones. Our analysis suggests that rising temperatures in drylands could alter the nonlinearities that determine the relative costs and benefits of variance in precipitation for primary production.


Asunto(s)
Clima , Ecosistema , Cambio Climático , New Mexico , Temperatura
3.
J Antimicrob Chemother ; 72(1): 246-253, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27629070

RESUMEN

OBJECTIVES: We evaluated whether maintenance therapy with atazanavir/ritonavir plus lamivudine (ATV/r + 3TC) was non-inferior to ATV/r plus two nucleosides (ATV/r + 2NUCs) at 96 weeks of follow-up. METHODS: SALT is a multicentre, open-label, non-inferiority clinical trial in HIV-1-infected virologically suppressed patients. Hepatitis B virus surface antigen-negative subjects with no previous treatment failure/resistance mutations and HIV-1-RNA <50 copies/mL for ≥6 months were randomized (1 : 1) to ATV/r + 3TC or ATV/r + 2NUCs. The primary endpoint was HIV-1-RNA <50 copies/mL in the PP population. Non-inferiority was demonstrated if the lower bound of the 95% CI for the difference was not below -12%. RESULTS: Some 286 patients were analysed. At week 96, 74.4% had HIV-1-RNA <50 copies/mL in the ATV/r + 3TC arm versus 73.9% in the ATV/r + 2NUCs arm (95% CI for the difference, -9.9%-11.0%). In both groups, similar values were observed for patients with confirmed virological failure in ATV/r + 3TC versus ATV/r + 2NUCs (9 versus 5), death (1 versus 0), discontinuation due to ART-related toxicity (7 versus 11), withdrawal from the study (7 versus 9) and loss to follow-up (6 versus 6). One patient taking ATV/r + 2NUCs developed resistance mutations (M184V and L63P). Similar values were obtained for change in mean CD4 count [19 versus 18 cells/mm3 (95% CI for the difference, -49.3-50.7), grade 3-4 adverse events (70.7% versus 70.2%) and changes in the global deficit score, -0.3 (95% CI, -0.5 to -0.1) for ATV/r + 3TC, versus -0.2 (95% CI, -0.4 to -0.1) for ATV/r + 2NUCs]. CONCLUSIONS: The long-term results of switching to ATV/r + 3TC show that this strategy is effective, safe and non-inferior to ATV + 2NUCs in virologically suppressed HIV-infected patients.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa/métodos , Quimioterapia de Mantención/métodos , Adulto , Anciano , Anciano de 80 o más Años , Fármacos Anti-VIH/efectos adversos , Terapia Antirretroviral Altamente Activa/efectos adversos , Femenino , Humanos , Quimioterapia de Mantención/efectos adversos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Carga Viral , Adulto Joven
4.
Ultrasound Obstet Gynecol ; 46(6): 678-87, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25684100

RESUMEN

OBJECTIVES: To identify at prenatal ultrasound (US) the features of apparently isolated subependymal pseudocysts (SEPC) that may indicate underlying pathology and should lead to further investigations. METHODS: This was a retrospective study of cases with SEPC detected on prenatal US and/or magnetic resonance imaging (MRI). Those with apparently isolated SEPC at US were classified into two groups as follows: Group 1 (n = 29): normal prenatal US and MRI (except for SEPC) and normal outcome; Group 2 (n = 12): normal prenatal cerebral US (except for SEPC) and abnormal prenatal cerebral MRI with or without abnormal outcome. A third group (n = 9) included cases with abnormal prenatal US and MRI. The latter cases with obvious cerebral abnormalities at US were excluded from the statistical analysis as they do not represent a diagnostic dilemma for clinicians. Groups 1 and 2 were analyzed, comparing them with respect to their SEPC characteristics (size, number, location in relation to the caudothalamic notch and the ventricular horns and morphology) and extracerebral abnormalities. RESULTS: The mean ± SD SEPC great axis was longer in Group 2 (11.67 ± 5.82 mm) than it was in Group 1 (8.00 ± 5.64 mm) (P = 0.021), suggesting an optimal cut-off for size of SEPC of ≥ 9 mm (sensitivity = 75%, specificity = 62%) to maximize sensitivity for predicting pathological outcome. SEPC adjacent to the temporal horns and SEPC located posterior to the caudothalamic notch were observed more frequently in Group 2, indicating their association with poor outcome (P = 0.003 and P = 0.003, respectively). Atypical morphology and extracerebral abnormalities were observed more frequently in Group 2 (P = 0.013 and P = 0.044, respectively). There was no statistically significant difference between groups for either number or location of cysts along the inferior wall or adjacent to the lateral wall of the frontal horns (P = 0.591 and P = 0.156, respectively). CONCLUSION: When apparently isolated SEPC are observed at prenatal US, further investigations should be performed under the following circumstances: (1) SEPC great axis ≥ 9 mm; (2) SEPC adjacent to the occipital and temporal horns; (3) SEPC located posterior to the caudothalamic notch; (4) SEPC with atypical morphology.


Asunto(s)
Encefalopatías/embriología , Quistes/embriología , Enfermedades Fetales/diagnóstico , Imagen por Resonancia Magnética/estadística & datos numéricos , Ultrasonografía Prenatal/estadística & datos numéricos , Adulto , Encefalopatías/diagnóstico por imagen , Quistes/diagnóstico por imagen , Femenino , Enfermedades Fetales/diagnóstico por imagen , Humanos , Recién Nacido , Valor Predictivo de las Pruebas , Embarazo , Resultado del Embarazo , Estudios Retrospectivos , Sensibilidad y Especificidad
5.
Ecology ; 94(9): 2030-41, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24279274

RESUMEN

The performance of many desert plant species in North America may decline with the warmer and drier conditions predicted by climate change models, thereby accelerating land degradation and reducing ecosystem productivity. We paired repeat measurements of plant canopy cover with climate at multiple sites across the Chihuahuan Desert over the last century to determine which plant species and functional types may be the most sensitive to climate change. We found that the dominant perennial grass, Bouteloua eriopoda, and species richness had nonlinear responses to summer precipitation, decreasing more in dry summers than increasing with wet summers. Dominant shrub species responded differently to the seasonality of precipitation and drought, but winter precipitation best explained changes in the cover of woody vegetation in upland grasslands and may contribute to woody-plant encroachment that is widespread throughout the southwestern United States and northern Mexico. Temperature explained additional variability of changes in cover of dominant and subdominant plant species. Using a novel empirically based approach we identified "climate pivot points" that were indicative of shifts from increasing to decreasing plant cover over a range of climatic conditions. Reductions in cover of annual and several perennial plant species, in addition to declines in species richness below the long-term summer precipitation mean across plant communities, indicate a decrease in the productivity for all but the most drought-tolerant perennial grasses and shrubs in the Chihuahuan Desert. Overall, our regional synthesis of long-term data provides a robust foundation for forecasting future shifts in the composition and structure of plant assemblages in the largest North American warm desert.


Asunto(s)
Clima Desértico , Sequías , Ecosistema , Calor , Plantas/clasificación , Animales , Demografía , Estaciones del Año , Especificidad de la Especie
6.
J Microencapsul ; 30(2): 181-8, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23088320

RESUMEN

This article describes the development of a freeze-dried formulation of chitosan (CS) nanocapsules containing docetaxel (DCX) and the evaluation of its efficacy in the NCI-H460 cancer cell line. More specifically, two prototypes of nanocapsules differing in their coating, CS alone or in combination with poloxamer 188 were developed using the solvent displacement technique. These prototypes (150 nm and +45 mV) exhibited high encapsulation efficiencies of DCX (78%) and very similar release profiles. The nanocapsules made of solely CS could be freeze-dried and reconstituted without altering their particle size distribution. CS nanocapsules were tested for their ability to deliver intracellularly the anticancer drug DCX. The results showed that CS nanocapsules maintained the antiproliferative effect of the drug and that it was not affected by the freeze-drying process. Moreover, it was found that this cytostatic effect of DCX was related to its intracellular delivery in the cancer cells.


Asunto(s)
Antineoplásicos , Quitosano , Sistemas de Liberación de Medicamentos/métodos , Nanocápsulas/química , Neoplasias/tratamiento farmacológico , Taxoides , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Quitosano/química , Quitosano/farmacocinética , Quitosano/farmacología , Docetaxel , Liofilización , Humanos , Neoplasias/metabolismo , Neoplasias/patología , Poloxámero/química , Poloxámero/farmacocinética , Poloxámero/farmacología , Taxoides/química , Taxoides/farmacocinética , Taxoides/farmacología
7.
Microbiol Resour Announc ; 11(5): e0013922, 2022 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-35420463

RESUMEN

We present the draft genome sequence of Gordonia sp. strain Campus, which was extracted from diesel-contaminated soil in Córdoba, Argentina. It was observed that this strain, in conjunction with alfalfa and poplar, has the ability to decompose diesel-contaminated soils. The data may be important for the phytoremediation of hydrocarbon-contaminated soils.

8.
HIV Med ; 11(9): 545-53, 2010 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-20345884

RESUMEN

BACKGROUND: Atazanavir (ATV) boosted with ritonavir (ATV/r) is a potent, well-tolerated, once-daily protease inhibitor (PI). Few data are available on this agent as a treatment simplification option for patients taking other PIs. OBJECTIVE: The aim of the study was to determine the effectiveness and safety of ATV-containing regimens in patients who have simplified their antiretroviral treatment. METHODS: SIMPATAZ was a multicentre, prospective, noninterventional study in patients who had undetectable HIV RNA on their current PI-containing therapy and who were switched to an ATV/r-based regimen. Patients underwent a routine physical examination, and data were collected on HIV RNA levels, CD4 cell counts, liver function, lipid parameters, adverse reactions, adherence to treatment and patient satisfaction. RESULTS: A total of 183 patients were enrolled in the study and included in the analysis (80% were male, 29% had AIDS, and 52% were coinfected with HIV and hepatitis B virus or hepatitis C virus). The median baseline CD4 count was 514 cells/µL. Median exposure to previous HIV therapy was 8 years, and 32% of patients had a history of PI failures. Lopinavir boosted with ritonavir was the most frequent PI replaced (62%) and tenofovir+lamivudine /emtricitabine the backbone most used during the study (29%). The study drug was discontinued early by 25 patients (14%), two of whom discontinued as a result of adverse events (Hodgkin lymphoma and vomiting). Two patients died (lung cancer and myocardial infarction). At month 12, 93% of the study population had an undetectable HIV RNA viral load. Hyperbilirubinaemia >3 mg/dL and increased alanine aminotransferase levels>200 IU/L were observed in 38.5% and 4.4% of patients, respectively. Median changes from baseline to month 12 in total cholesterol, triglycerides and low-density lipoprotein cholesterol were -13 mg/dL (-7%; P<0.0001), -19 mg/dL (-13%; P<0.0001) and -7 mg/dL (-6%; P=0.021), respectively. CONCLUSIONS: In a real-world setting, switching from other PIs to ATV/r is a well-tolerated and safe option for improving the lipid profile and for retaining virological response in controlled pretreated patients.


Asunto(s)
Terapia Antirretroviral Altamente Activa/métodos , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/uso terapéutico , Oligopéptidos/uso terapéutico , Piridinas/uso terapéutico , Ritonavir/uso terapéutico , Adulto , Sulfato de Atazanavir , Recuento de Linfocito CD4 , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Ayuno , Femenino , Infecciones por VIH/sangre , Infecciones por VIH/inmunología , Inhibidores de la Proteasa del VIH/administración & dosificación , Hepatitis Viral Humana/complicaciones , Humanos , Masculino , Cumplimiento de la Medicación , Persona de Mediana Edad , Oligopéptidos/administración & dosificación , Satisfacción del Paciente , Estudios Prospectivos , Piridinas/administración & dosificación , Ritonavir/administración & dosificación , Transaminasas/sangre , Resultado del Tratamiento , Triglicéridos/sangre , Carga Viral
9.
J Antimicrob Chemother ; 63(6): 1256-63, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19363085

RESUMEN

OBJECTIVES: The two currently available types of pegylated interferon (peg-IFN) used to treat hepatitis C have different pharmacokinetic properties. It is unclear how these differences affect response to therapy. We compared the effectiveness and safety of peg-IFN-alpha2a and peg-IFN-alpha2b, both with ribavirin, against chronic hepatitis C virus (HCV) infection in HIV-infected patients. METHODS: From the GESIDA HIV/HCV cohort, we analysed patients treated with peg-IFN-alpha2a (n = 315) or peg-IFN-alpha2b (n = 242). The primary endpoint was a sustained virological response (SVR). RESULTS: Both groups were well matched in baseline characteristics except for a higher frequency of injection drug users in the peg-IFN-alpha2b group than in the peg-IFN-alpha2a group (85% versus 76%; P = 0.01) and a higher frequency of bridging fibrosis and cirrhosis (F3-F4) in the peg-IFN-alpha2b group than in the peg-IFN-alpha2a group (42% versus 33%; P = 0.04). End-of-treatment response was significantly lower among patients treated with peg-IFN-alpha2b [40% versus 52%; odds ratio (OR), 1.63; 95% confidence interval (95% CI), 1.16-2.29; P < 0.01]. However, no significant differences were found in SVR between patients treated with peg-IFN-alpha2b and those treated with peg-IFN-alpha2a (31% versus 33%; OR, 1.09; 95% CI, 0.75-1.59; P = 0.655). Therapy was interrupted due to adverse events in 33 (14%) patients treated with peg-IFN-alpha2b and 47 (15%) patients treated with peg-IFN-alpha2a. CONCLUSIONS: No differences in effectiveness and safety were found between peg-IFN-alpha2b and peg-IFN-alpha2a for the treatment of chronic HCV infection in HIV-infected patients.


Asunto(s)
Antivirales/uso terapéutico , Infecciones por VIH/complicaciones , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Adulto , Antivirales/efectos adversos , Femenino , Humanos , Interferón alfa-2 , Interferón-alfa/efectos adversos , Masculino , Polietilenglicoles/efectos adversos , Proteínas Recombinantes , Ribavirina/efectos adversos , Resultado del Tratamiento
10.
Rev. Soc. Esp. Dolor ; 30(2): 72-78, 2023. tab, graf
Artículo en Español | IBECS (España) | ID: ibc-225564

RESUMEN

Objetivo: Evaluar el grado de satisfacción de los pacientes y/o cuidadores con el tratamiento de citrato de fentanilo transmucosa en la gestión de las crisis de dolor irruptivo oncológico en términos de facilidad de uso. Métodos: Se realizó un estudio observacional, prospectivo y multicéntrico con 48 pacientes sometidos a tratamiento de mantenimiento con opioides para el dolor crónico basal provocado por el cáncer y que, además, sufrían crisis de dolor irruptivo para las que estaban recibiendo tratamiento con citrato de fentanilo. La variable principal del estudio fue el grado de satisfacción de los pacientes y/o sus cuidadores con el citrato de fentanilo en el manejo de las crisis de dolor irruptivo oncológico, evaluadas mediante cuestionarios Escala Visual Analógica (EVA). Resultados: El 90,6 % de los pacientes/cuidadores muestran un elevado grado de satisfacción con el empleo de citrato de fentanilo en términos de facilidad de uso (valor medio EVA de 8,2). Por su parte, tanto la valoración general por parte de los pacientes/cuidadores como por parte de los sanitarios ha sido muy positiva (valor medio EVA 7,7). Conclusiones: El citrato de fentanilo es una terapia fácil de usar y eficaz para el tratamiento de las crisis de dolor irruptivo oncológico, con amplia aceptación tanto por parte de pacientes y cuidadores como de los profesionales sanitarios.(AU)


Objective: To assess the degree of satisfaction of patients and/or caregivers with transmucosal fentanyl citrate treatment in the management of breakthrough cancer pain crises in terms of ease of use. Methods: An observational, prospective and multicenter study was carried out with 48 patients undergoing maintenance treatment with opioids for baseline chronic cancer pain and who, in addition, suffered breakthrough pain crises for those who were receiving treatment with fentanyl citrate. The main variable of the study was the degree of satisfaction of the patients and/or their caregivers with fentanyl citrate in the management of breakthrough cancer pain crises, evaluatedby means of Visual Analogue Scale (VAS) questionnaires. Results: 90.6 % of patients/caregivers show a high degree of satisfaction with the use of fentanyl citrate in terms of ease of use (mean VAS value of 8.2). For its part, both the general assessment by the patients/caregivers and by the healthcare professionals has been very positive (mean VAS value 7.7). Conclusions: Fentanyl citrate is an easy-to-use and effective therapy for the treatment of breakthrough cancer pain crises, widely accepted by both patients and caregivers as well as health professionals.(AU)


Asunto(s)
Humanos , Masculino , Femenino , Satisfacción del Paciente , Ácido Cítrico , Dolor en Cáncer/tratamiento farmacológico , Fentanilo , Dolor Irruptivo/terapia , Administración a través de la Mucosa , Dolor/tratamiento farmacológico , Dimensión del Dolor , Manejo del Dolor , Estudios Prospectivos , Oncología Médica , Encuestas y Cuestionarios
11.
An Sist Sanit Navar ; 40(2): 309-314, 2017 Aug 31.
Artículo en Español | MEDLINE | ID: mdl-28765663

RESUMEN

Pulmonary epithelioid hemangioendothelioma is an uncommon neoplastic disease of endothelial origin, with an incidence inferior to one in a million. It usually behaves as a low-grade malignancy; nevertheless, a few cases have been described in which this tumour manifests a highly aggressive behavior, spreading throughout the organism. We report the case of a 77-year-old woman who was diagnosed with metastatic pulmonary epithelioid hemangioendothelioma with severe symptoms, requiring urgent treatment to palliate them. Key words. Epithelioid hemangioendothelioma. Lung.


Asunto(s)
Hemangioendotelioma Epitelioide , Neoplasias Pulmonares , Anciano , Resultado Fatal , Femenino , Hemangioendotelioma Epitelioide/diagnóstico , Hemangioendotelioma Epitelioide/terapia , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia
12.
Surg Neurol ; 11(1): 21-3, 1979 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-572095

RESUMEN

A case of a choriocarcinoma within the third ventricle in an eight-year-old girl is described. The patient died suddenly five days after operation. The post mortem examination showed an intraventricular hemorrhage with obstruction of the foramina of Monroe. An additional case in a 16-year-old young man, with similar location and without necropsy, is described. Discussion of the primary origin and etiology of these tumors is presented.


Asunto(s)
Neoplasias del Ventrículo Cerebral/patología , Coriocarcinoma/patología , Adolescente , Neoplasias del Ventrículo Cerebral/diagnóstico por imagen , Neoplasias del Ventrículo Cerebral/etiología , Niño , Coriocarcinoma/diagnóstico por imagen , Coriocarcinoma/etiología , Femenino , Humanos , Masculino , Embarazo , Radiografía
13.
Virus Res ; 152(1-2): 96-103, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20600394

RESUMEN

Mal de Río Cuarto virus (MRCV) is a plant virus of the genus Fijivirus within the family Reoviridae that infects several monocotyledonous species and is transmitted by planthoppers in a persistent and propagative manner. Other members of the family replicate in viral inclusion bodies (VIBs) termed viroplasms that are formed in the cytoplasm of infected plant and insect cells. In this study, the protein coded by the first ORF of MRCV segment S9 (P9-1) was shown to establish cytoplasmic inclusion bodies resembling viroplasms after transfection of Spodoptera frugiperda insect cells. In accordance, MRCV P9-1 self-associates giving rise to high molecular weight complexes when expressed in bacteria. Strong self-interaction was also evidenced by yeast two-hybrid assays. Furthermore, biochemical characterization showed that MRCV P9-1 bound single stranded RNA and had ATPase activity. Finally, the MRCV P9-1 region required for the formation of VIB-like structures was mapped to the protein carboxy-terminal half. This extensive functional and biochemical characterization of MRCV P9-1 revealed further similarities between plant and animal reovirus viroplasm proteins.


Asunto(s)
Cuerpos de Inclusión Viral/metabolismo , Reoviridae/metabolismo , Spodoptera/virología , Proteínas Virales/metabolismo , Secuencias de Aminoácidos , Animales , Cuerpos de Inclusión Viral/química , Cuerpos de Inclusión Viral/genética , Sistemas de Lectura Abierta , Reoviridae/química , Reoviridae/genética , Proteínas Virales/química , Proteínas Virales/genética
14.
Oecologia ; 155(1): 123-32, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17968592

RESUMEN

Aboveground net primary production (ANPP) dynamics are a key element in the understanding of ecosystem processes. For semiarid environments, the pulse-reserve framework links ANPP to variable and unpredictable precipitation events contingent on surficial hydrology, soil moisture dynamics, biodiversity structure, trophic dynamics, and landscape context. Consequently, ANPP may be decoupled periodically from processes such as decomposition and may be subjected to complex feedbacks and thresholds at broader scales. As currently formulated, the pulse-reserve framework may not encompass the breadth of ANPP response to seasonal patterns of precipitation and heat inputs. Accordingly, we examined a 6-year (1999-2004), seasonal record of ANPP with respect to precipitation, soil moisture dynamics, and functional groups in a black grama (Bouteloua eriopoda) grassland and a creosotebush (Larrea tridentata) shrubland in the northern Chihuahuan Desert. Annual ANPP was similar in the grassland (51.1 g/m(2)) and shrubland (59.2 g/m(2)) and positively correlated with annual precipitation. ANPP differed among communities with respect to life forms and functional groups and responses to abiotic drivers. In keeping with the pulse-reserve model, ANPP in black grama grassland was dominated by warm-season C(4) grasses and subshrubs that responded to large, transient summer storms and associated soil moisture in the upper 30 cm. In contrast, ANPP in creosotebush shrubland occasionally responded to summer moisture, but the predominant pattern was slower, non-pulsed growth of cool-season C(3) shrubs during spring, in response to winter soil moisture accumulation and the breaking of cold dormancy. Overall, production in this Chihuahuan Desert ecosystem reflected a mix of warm-temperate arid land pulse dynamics during the summer monsoon and non-pulsed dynamics in spring driven by winter soil moisture accumulation similar to that of cool-temperate regions.


Asunto(s)
Clima Desértico , Ecosistema , Biodiversidad , Ambiente , Magnoliopsida , New Mexico , Poaceae , Análisis de Regresión
15.
J Neurosci Res ; 82(6): 822-30, 2005 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-16302188

RESUMEN

Apotransferrin (aTf), has been shown to accelerate the differentiation of oligodendroglial cells (OLGcs) in primary cultures and to increase the expression of different components of the myelin cytoskeleton (CSK). We examined the incorporation and distribution of human aTf (aTfh) exogenously added to OLGcs cultures and its effects on the CSK of the OLGcs. When OLGcs treated with aTfh were extracted with a CSK-stabilizing buffer containing detergent, aTfh was found in the soluble fraction. In vitro experiments showed that purified tubulin was not altered by the addition of aTfh. In OLGc primary cultures treated with aTfh, this glycoprotein showed a punctate distribution pattern along the OLGc processes. Treatment of the cultures with colchicine, cytochalasin, or taxol induced a displacement of the immunoreactivity of aTfh toward the OLGc soma. Analysis of the effects of aTfh on the cell distribution of tyrosinated and detyrosinated tubulin and STOP (stable tubule only polypeptide), showed that aTfh added to OLGc cultures promoted changes suggesting a stabilizing effect on the microtubules (MT) at the tip of the processes. Kinesin and dynein were found to colocalize with the aTfh, indicating that these motors participate in the transport of the added glycoprotein. Moreover, after treatment with aTfh, clathrin immunoreactivity was displaced from the OLGc body toward the cell processes. These results indicate that although aTfh added to OLGcs does not interact directly with CSK components, it seems to be transported in clathrin coated vesicles from the cell body to the tips of the OLGc processes where it promotes their stabilization. This mechanism may be of importance in the increased formation of the myelin membrane induced by aTf.


Asunto(s)
Apoproteínas/farmacología , Citoesqueleto/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Oligodendroglía/efectos de los fármacos , Transferrina/farmacología , Animales , Animales Recién Nacidos , Western Blotting/métodos , Células Cultivadas , Corteza Cerebral/citología , Citocalasinas/farmacología , Citoesqueleto/metabolismo , Regulación de la Expresión Génica/fisiología , Humanos , Inmunohistoquímica/métodos , Microscopía Confocal/métodos , Proteínas Asociadas a Microtúbulos/metabolismo , Oligodendroglía/metabolismo , Ratas , Ratas Wistar , Receptores de Transferrina/metabolismo , Tubulina (Proteína)/metabolismo
16.
Childs Brain ; 3(5): 304-8, 1977.
Artículo en Inglés | MEDLINE | ID: mdl-902513

RESUMEN

The clinical, operative and autopsy findings associated with a huge meningioma in an 8-month-old boy are described. Especially noteworthy are the patient's age, the size of the tumour and the poorness of neurological symptoms.


Asunto(s)
Neoplasias Meníngeas/congénito , Meningioma/congénito , Humanos , Hidrocefalia/etiología , Lactante , Masculino , Neoplasias Meníngeas/diagnóstico , Meningioma/diagnóstico
18.
Rev. argent. cir ; 62(3/4): 99-100, mar.-abr. 1992.
Artículo en Español | LILACS | ID: lil-105805

RESUMEN

El objetivo de este trabajo es presentar la experiencia inicial en safenectomía y ligadura de perforantes (Linton) ambulatorias. El programa implementado consiste en el ingreso al hospital a las 6,00, anestesia peridural a las 6,30, cirugía a las 7,00, fin de cirugía 8,45, con internación transitoria con vendaje elástico ajustado. Luego de control, alta alrededor de las 18,00. Se operaron, en un período de 6 meses, 10 mujeres y 5 hombres en su gran mayoría con dolor, pesadez, edema y prurito. Se realizó safenectomía y ligadura de perforantes según técnica clásica. Duración del período de internación: 12 hs. Complicaciones: 1 hematoma de la ingle. Número de consultas externas desde el diagnóstico hasta el alta en la 5* semana: 4. Todos los pacientes se reintegraron a sus tareas habituales en el 8* días postoperatorio. La cirugía venosa mayor puede realizarse en un programa ambulatorio con buena tolerancia por parte del paciente. El procedimiento resultó ser eficiente, sin complicaciones y expeditivo. Se continuará con el programa para informar sobre su resultado alejado en un número mayor de pacientes


Asunto(s)
Procedimientos Quirúrgicos Ambulatorios , Várices/cirugía , Procedimientos Quirúrgicos Ambulatorios/estadística & datos numéricos , Extremidades , Pierna , Vena Safena/cirugía , Muslo
19.
Rev. argent. cir ; 62(3/4): 99-100, mar.-abr. 1992.
Artículo en Español | BINACIS | ID: bin-26459

RESUMEN

El objetivo de este trabajo es presentar la experiencia inicial en safenectomía y ligadura de perforantes (Linton) ambulatorias. El programa implementado consiste en el ingreso al hospital a las 6,00, anestesia peridural a las 6,30, cirugía a las 7,00, fin de cirugía 8,45, con internación transitoria con vendaje elástico ajustado. Luego de control, alta alrededor de las 18,00. Se operaron, en un período de 6 meses, 10 mujeres y 5 hombres en su gran mayoría con dolor, pesadez, edema y prurito. Se realizó safenectomía y ligadura de perforantes según técnica clásica. Duración del período de internación: 12 hs. Complicaciones: 1 hematoma de la ingle. Número de consultas externas desde el diagnóstico hasta el alta en la 5* semana: 4. Todos los pacientes se reintegraron a sus tareas habituales en el 8* días postoperatorio. La cirugía venosa mayor puede realizarse en un programa ambulatorio con buena tolerancia por parte del paciente. El procedimiento resultó ser eficiente, sin complicaciones y expeditivo. Se continuará con el programa para informar sobre su resultado alejado en un número mayor de pacientes


Asunto(s)
Várices/cirugía , Procedimientos Quirúrgicos Ambulatorios/métodos , Procedimientos Quirúrgicos Ambulatorios/estadística & datos numéricos , Vena Safena/cirugía , Extremidades , Pierna , Muslo
20.
Buenos Aires; Universidad Nacional de Buenos Aires. Facultad de Ciencias Médicas; 1885. [900] p. ilus. (60367).
Monografía en Español | BINACIS | ID: bin-60367
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA