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1.
Proc Natl Acad Sci U S A ; 120(30): e2216686120, 2023 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-37459512

RESUMEN

Many school systems across the globe turned to online education during the COVID-19 pandemic. This context differs significantly from the prepandemic situation in which massive open online courses attracted large numbers of voluntary learners who struggled with completion. Students who are provided online courses by their high schools also have their behavior determined by actions of their teachers and school system. We conducted experiments to improve participation in online learning before, during, and right after the COVID-19 outbreak, with 1,151 schools covering more than 45,000 students in their final years of high school in Ecuador. These experiments tested light-touch interventions at scale, motivated by behavioral science, and were carried out at three levels: that of the system, teacher, and student. We find the largest impacts come from intervening at the system level. A cheap, online learning management system for centralized monitoring increased participation by 0.21 SD and subject knowledge by 0.13 SD relative to decentralized management. Centralized management is particularly effective for underperforming schools. Teacher-level nudges in the form of benchmarking emails, encouragement messages, and administrative reminders did not improve student participation. There was no significant impact of encouragement messages to students, or in having them plan and team-up with peers. Small financial incentives in the form of lottery prizes for finishing lessons did increase study time, but was less cost-effective, and had no significant impact on knowledge. The results show the difficulty in incentivizing online learning at scale, and a key role for central monitoring.


Asunto(s)
COVID-19 , Educación a Distancia , Humanos , Pandemias/prevención & control , COVID-19/epidemiología , COVID-19/prevención & control , Instituciones Académicas , Estudiantes
2.
Appl Opt ; 55(2): 254-8, 2016 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-26835760

RESUMEN

A method based on laser induced breakdown spectroscopy (LIBS) for monitoring lead and copper accumulation in edible fish, particularly "tilapia del Nilo" (Oreochromis niloticus) is presented. The capability of this analytical method is compared with results obtained by atomic absorption spectrometry. Detection limits by LIBS are 25 parts per million (ppm) for Pb and 100 ppm for Cu, values that are below the maximum permissible levels of some international standards. Application of LIBS detection allows the development of portable instruments for contamination control of edible fish.


Asunto(s)
Rayos Láser , Metales/toxicidad , Análisis Espectral/métodos , Tilapia/metabolismo , Animales , Calibración , Límite de Detección , Músculos/metabolismo
3.
GEN ; 69(2): 50-55, jul. 2015. ilus, graf, mapas
Artículo en Español | LILACS | ID: lil-780152

RESUMEN

Introducción: La Gastroenteritis eosinofilica, se refiere a la eosinofilia en cualquiera de las capas de la pared del tracto gastrointestinal, es una patología rara, con incidencia no reportada y de patogenia desconocida, asociada a antecedentes de atopias y alergias alimentarias. Se requiere para su diagnóstico la evidencia histológica de eosinofilia, la ausencia de ésta en órganos extraintestinales y sin presencia de infección parasitaria. Caso clínico: Se reporta el caso de una paciente femenina de 39 años de edad, con clínica de 4 meses que inició posterior a intoxicación alimentaria y caracterizada por dolor abdominal difuso con predominio de epigástrico, opresivo, de fuerte intensidad, que mejoraba con uso de antiespasmódicos y se intensificaba con la ingestión de alimentos, acompañado de náuseas y vómitos. Se planteó el diagnóstico por imágenes de litiasis vesicular, siendo sometida a colecistectomía laparoscópica. Por persistencia de la sintomatología se realizó endoscopia digestiva superior con hallazgos sugestivos de: gastroduodenitis parasitaria y la biopsia reportó: gastroduodenitis crónica severa eosinofilica. Se indicó tratamiento a base de prednisona, obteniendo resolución completa del cuadro clínico.


Background: eosinophilic gastroenteritis, refers to eosino- philia in any of the layers of the wall of the gastrointestinal tract, it is a rare condition, with no reported incidence and unknown pathogenesis associated with a history of atopy and food allergies. It required for diagnosis histologic evidence of eosinophilia, its absence in intestinal organs without presence of parasitic infection. Case report: The case of a female patient of 39 years old, with clinical started 4 months after food poisoning, characterized by a predominance of diffuse abdominal pain epigastric, oppressive, strong intensity, which improved with use is reported antispasmodics and intensified with food intake, with nausea and vomiting. The imaging of gallstones was raised, undergoing laparoscopic cholecystec- tomy. Persistence of symptoms upper endoscopy is performed with suggestive findings: parasitic gastroduodenitis and biop- sy reported: severe chronic eosinophilic gastroduodenitis. Treatment with prednisone was indicated, obtaining complete resolution of symptoms.

4.
Rev Calid Asist ; 29(3): 143-9, 2014.
Artículo en Español | MEDLINE | ID: mdl-24507898

RESUMEN

INTRODUCTION: having an appropriate patient safety culture is the first recommendation to improve it. The aim of this article is to determine the safety culture in family medicine residents and then to identify improvement strategies. METHODS: an online cross-sectional survey of residents in family medicine teaching units of Aragon using the translated, validated and adapted to Spanish, Medical Office Survey on Patient Safety Culture (MOSPS) questionnaire. The results were grouped in 12-dimensional responses for analysis, and the mean value of each dimension was calculated. Perceptions were described by Percentages of Positive (PRP) and Negative Responses (PRN) to each dimension. RESULTS: positive results were seen in «the Patient Care Tracking/Follow-up¼. There were significant differences in the «Information Exchange With Other Settings¼, «Staff Training¼ and «Overall Perceptions of Patient Safety and Quality¼. Study participants viewed «Work Pressure and Pace¼ negatively. CONCLUSIONS: the institutions providing health services, as well as their staff, are increasingly aware of the importance of improving Patient Safety, and the results of this study allowed us to present information that helps identify weaknesses, and to design initiatives and strategies to improve care practices.


Asunto(s)
Medicina Comunitaria , Medicina Familiar y Comunitaria , Internado y Residencia , Cultura Organizacional , Seguridad del Paciente , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , España , Encuestas y Cuestionarios , Adulto Joven
5.
Purinergic Signal ; 10(2): 269-81, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24014158

RESUMEN

D(1)- and D(2)-types of dopamine receptors are located separately in direct and indirect pathway striatal projection neurons (dSPNs and iSPNs). In comparison, adenosine A(1)-type receptors are located in both neuron classes, and adenosine A(2A)-type receptors show a preferential expression in iSPNs. Due to their importance for neuronal excitability, Ca(2+)-currents have been used as final effectors to see the function of signaling cascades associated with different G protein-coupled receptors. For example, among many other actions, D(1)-type receptors increase, while D(2)-type receptors decrease neuronal excitability by either enhancing or reducing, respectively, CaV1 Ca(2+)-currents. These actions occur separately in dSPNs and iSPNs. In the case of purinergic signaling, the actions of A(1)- and A(2A)-receptors have not been compared observing their actions on Ca(2+)-channels of SPNs as final effectors. Our hypotheses are that modulation of Ca(2+)-currents by A(1)-receptors occurs in both dSPNs and iSPNs. In contrast, iSPNs would exhibit modulation by both A(1)- and A2A-receptors. We demonstrate that A(1)-type receptors reduced Ca(2+)-currents in all SPNs tested. However, A(2A)-type receptors enhanced Ca(2+)-currents only in half tested neurons. Intriguingly, to observe the actions of A(2A)-type receptors, occupation of A(1)-type receptors had to occur first. However, A(1)-receptors decreased Ca(V)2 Ca(2+)-currents, while A(2A)-type receptors enhanced current through Ca(V)1 channels. Because these channels have opposing actions on cell discharge, these differences explain in part why iSPNs may be more excitable than dSPNs. It is demonstrated that intrinsic voltage-gated currents expressed in SPNs are effectors of purinergic signaling that therefore play a role in excitability.


Asunto(s)
Cuerpo Estriado/metabolismo , Potenciales de la Membrana/fisiología , Neuronas/metabolismo , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2A/metabolismo , Animales , Masculino , Técnicas de Placa-Clamp , Ratas , Ratas Wistar
6.
Rheumatol Int ; 33(12): 3065-8, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23160601

RESUMEN

Kikuchi's disease, also known as histiocytic necrotizing lymphadenitis, is a rare, benign, and self-limited disorder of unknown cause that is usually characterized by cervical lymphadenopathy and fever. The etiology and pathogenesis remain unknown, but the clinical presentation, course, and histologic changes suggest an immune response of T cells and histiocytes to an infectious agent. Numerous inciting agents have been proposed. However, the association between human herpesvirus 7 and Kikuchi's disease has been rarely reported as a possible etiologic agent of Kikuchi's disease. We report the case of a 24-year-old Caucasian female patient with cervical lymphadenopathy and isolated pruriginous maculo-papular lesions who was diagnosed of Kikuchi's disease in whom the presence of human herpesvirus 7 DNA was documented in the affected lymph node specimen in the absent of other viruses. Therefore, a possible etiologic relation between the Kikuchi's disease of this patient and human herpesvirus 7 was established, supporting a role for human herpesvirus 7 involvement in the pathogenesis.


Asunto(s)
Herpesvirus Humano 7/fisiología , Linfadenitis Necrotizante Histiocítica/virología , Infecciones por Roseolovirus/complicaciones , Apoptosis , ADN Viral/genética , Femenino , Herpesvirus Humano 7/genética , Histiocitos/patología , Linfadenitis Necrotizante Histiocítica/patología , Linfadenitis Necrotizante Histiocítica/fisiopatología , Humanos , Infecciones por Roseolovirus/patología , Infecciones por Roseolovirus/fisiopatología , Adulto Joven
7.
J Genet ; 91(3): 265-77, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23271012

RESUMEN

The rodent genus Oecomys (Sigmodontinae) comprises ~16 species that inhabit tropical and subtropical forests in Central America and South America. In this study specimens of Oecomys paricola Thomas, 1904 from Belém and Marajó island, northern Brazil, were investigated using cytogenetic, molecular and morphological analyses. Three karyotypes were found, two from Belém (2n = 68, fundamental number (FN) = 72 and 2n = 70, FN = 76) and a third from Marajó island (2n = 70, FN = 72). No molecular or morphological differences were found between the individuals with differing cytotypes from Belém, but differences were evident between the individuals from Belém and Marajó island. Specimens from Belém city region may represent two cryptic species because two different karyotypes are present in the absence of significant differences in morphology and molecular characteristics. The Marajó island and Belém populations may represent distinct species that have been separated for some time, and are in the process of morphological and molecular differentiation as a consequence of reproductive isolation at the geographic and chromosomal levels. Thus, the results suggest that O. paricola may be a complex of species.


Asunto(s)
Cromosomas de los Mamíferos/genética , Citocromos b/genética , ADN Mitocondrial/genética , Sigmodontinae/genética , Animales , ADN Mitocondrial/química , Geografía , Cariotipo , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Sigmodontinae/anatomía & histología , Sigmodontinae/clasificación , América del Sur , Especificidad de la Especie
9.
Med. infant ; 15(2): 110-113, jun. 2008. graf, tab
Artículo en Español | LILACS, BINACIS, UNISALUD | ID: lil-494391

RESUMEN

El sindrome Urémico Hemolítico D+ (SUH) es la segunda causa de insuficiencia renal crónica terminal (IRCT) en edad pediátrica. La proteinuria es el principal modulador de la evolución a la cronicidad. En un grupo de pacientes tratados con dieta controlada en proteínas e inhibidores de la enzima de conversión de la Angiotensina II se demostró un enlentecimiento significativo en la progresión de la nefropatía a la IRCT. El objetivo de este trabajo fue evaluar, en una primera etapa, el impacto de la dieta normoproteica y normosódica sobre la proteinuria en pacientes con nefropatía secuelar por SUH y función renal normal (CI Cr >80ml/min/1.73m2). Métodos: como parte de un estudio de fase III longitudinal, multicéntrico, aleatorizado, doble ciego, de grupos paralelos (placebo y activo controlado con enalpril y losartan), se evaluó la diferencia entre la proteinuria antes y después de una dieta normósódica y mormoprotica, indicada según RDA. La ingesta proteica fue estimada mediante recordtorio de 72 horas y el cálculo de excreción de urea en orina de 24 horas. La proteinuria se dosó en orina de 24 hs. al comienzo del estudio, a los 30 y 60 días. Resultados: se incluyeron 102 pacientes cuyo rango de proteinuria fue entre 5.3 y 40.0 mg/kg/día de los cuales negativizaron 65 (63.7 por ciento) y no respondieron 37 (36,3 por ciento ). La mediana de edad del comienzo de la enfermedad fue de 16,5 meses (rango: 7.0-85.0 meses). El tiempo de evolución post SUG fue de 4.0 a 155.0 meses (mediana 48.0 meses) El valor de la proteinuria inicial en los 65 niños que respondieron fue de x 9.83 mg/kg/día (ES 0 o,34) y post dieta de de x =2,44 (ES 0 0,12) P < 0.0001. La media de las diferencias entre la natriuresis pre y post dieta no fue estadísticamente diferente de 0; t = 0,97 (x /ES). Conclusión: la dieta normoproteica es capaz de normalizar la proteinuria en el 63.7 por ciento de los pacientes con proteinuria significativa secundaria a SUH y función renal normal.


Asunto(s)
Lactante , Preescolar , Niño , Adolescente , Enalapril/uso terapéutico , Losartán/uso terapéutico , Proteinuria/dietoterapia , Síndrome Hemolítico-Urémico , Estudios Longitudinales , Estudios Multicéntricos como Asunto , Método Doble Ciego
10.
Oncogene ; 26(12): 1702-13, 2007 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-16983340

RESUMEN

Pharmacological inactivation of cancer genes or products is being used as a strategy for therapy in oncology. To investigate the potential role of BCR-ABLp190 cessation in leukaemia development, we generated mice carrying a tetracycline-repressible BCR-ABLp190 transgene. These mice were morphologically normal at birth, and developed leukaemias. Disease was characterized by the presence of B-cell blasts co-expressing myeloid markers, reminiscent of the human counterpart. BCR-ABLp190 activation can initiate leukaemia in both young and adult mice. Transitory expression of BCR-ABLp190 is enough to develop leukaemia. Suppression of the BCR-ABLp190 transgene in leukaemic CombitTA-p190 mice did not rescue the malignant phenotype, indicating that BCR-ABLp190 is not required to maintain the disease in mice. Similar results were obtained by inactivation of BCR-ABLp190 with STI571 (Gleevec; Novartis, East Hanover, NJ, USA) in leukaemic CombitTA-p190 mice. However, gradual suppression of BCR-ABLp190 in leukaemic CombitTA-p190 mice identified a minimum level of BCR-ABLp190 expression necessary to revert the specific block in B-cell differentiation in the leukaemic cells. Overall, the findings indicate that BCR-ABLp190 appears to cause epigenetic and/or genetic changes in tumour-maintaining cells that render them insensitive to BCR-ABLp190 inactivation.


Asunto(s)
Proteínas de Fusión bcr-abl/genética , Silenciador del Gen , Leucemia Experimental/genética , Animales , Secuencia de Bases , Línea Celular , Cartilla de ADN , Ratones , Ratones Transgénicos , Fenotipo
11.
Nefrologia ; 26(2): 278-82, 2006.
Artículo en Español | MEDLINE | ID: mdl-16808269

RESUMEN

We report a patient with end stage renal disease with lesions compatibles with renal vasculitis antineutrophil cytoplasmic autoantibody (ANCA)-associated in phase of sclerosis that underwent renal transplantation from a non-heart beating donor after one year of haemodialysis treatment, without evidence of active vasculitis. Post-transplantation management was performed according to our protocol in this kind of donors with immunosuppressive treatment based on daclizumab, half-doses of tacrolimus, mycophenolate mofetil and steroids. In the third week the renal biopsy showed an acute necrotizing vasculitis associated with crescent glomerulonephritis. The patient was initially diagnosed of acute vascular rejection and initiated treatment with 6-metilprednisolone and anti-CD3 monoclonal anti-bodies. Two days later he developed a cutaneous purpura and the skin biopsy showed an acute necrotizing vasculitis. The determination of circulating ANCA-anti-myeloperoxidase (MPO) was positive. We initiated treatment with oral cyclophosphamide plus mycophenolate mofetil discontinuation with rapid improvement of cutaneous lesions and initiation of renal function recovery.


Asunto(s)
Anticuerpos Anticitoplasma de Neutrófilos , Trasplante de Riñón , Vasculitis/inmunología , Vasculitis/cirugía , Humanos , Fallo Renal Crónico/cirugía , Masculino , Persona de Mediana Edad , Peroxidasa/inmunología , Recurrencia , Factores de Tiempo , Donantes de Tejidos , Vasculitis/patología
12.
Cytogenet Genome Res ; 114(1): 24-9, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16717446

RESUMEN

The Snail-related zinc-finger transcription factor, SLUG (SNAI2), is critical for the normal development of neural crest-derived cells and loss-of-function SLUG mutations have been proven to cause piebaldism and Waardenburg syndrome type 2 in a dose-dependent fashion. However, little is known about the consequences of SLUG overexpression in embryonic development. We report SLUG duplication in a child with a unique de novo 8q11.2-->q13.3 duplication associated with tetralogy of Fallot, submucous cleft palate, renal anomalies, hypotonia and developmental delay. To investigate the effects of Slug overexpression on development, we analyzed mice carrying a Slug transgene. These mice were morphologically normal at birth, inferring that Slug overexpression is not sufficient to cause overt morphogenetic defects. In the adult mice, there was a 20% incidence of sudden death, cardiomegaly and cardiac failure associated with incipient mesenchymal tumorigenesis. These findings, while not directly implicating Slug in congenital and acquired heart disease, raise the possibility that Slug overexpression may contribute to specific cardiac phenotypes and cancer development.


Asunto(s)
Cromosomas Humanos Par 8 , Desarrollo Embrionario/genética , Factores de Transcripción/genética , Trisomía , Anomalías Múltiples/genética , Animales , Southern Blotting , Mapeo Cromosómico , Duplicación de Gen , Regulación del Desarrollo de la Expresión Génica , Humanos , Hibridación Fluorescente in Situ , Lactante , Cariotipificación , Ratones , Ratones Transgénicos , Hibridación de Ácido Nucleico , Factores de Transcripción de la Familia Snail , Tetralogía de Fallot/genética
13.
Austral Ecol ; 30(8): 906-919, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32336941

RESUMEN

Abstract Patterns in the composition of assemblages of microbat species sampled during the late dry season (the 'build-up') in north Australian savannas were assessed against a range of environmental factors as well as four a priori defined habitat types (riparian, escarpments, coastal and woodlands). Distinct species assemblages were most strongly associated with topographic and climatic variables. There were also limited associations with vegetation structure, fire and local roost potential but no associations with insects or water availability. Total species diversity at sample sites was associated with distance to rivers and rainfall. In general, species assemblages were not clearly defined and the number of significant environmental associations was relatively few. We compare these associations with those reported for bat assemblages elsewhere in Australia.

14.
Med. infant ; 11(3): 196-198, sept. 2004.
Artículo en Español | LILACS | ID: lil-510175

RESUMEN

El bromato de potasio es un agente oxidante utilizado como aditivo en las harinas para mejorar el sabor y la textura del pan. Debido a sus efectos tóxicos está prohibido su uso desde el 11 de mayo de 1998, en todo el territorio nacional. Sin embargo su utilización no es infrecuente y se han descripto cuadros de ingesta accidental o deliberada. Describimos una intoxicación de 255 niños con bromato de potasio en una escuela de la localidad de Hipólito Irigoyen en la provincia de Salta en abril de 2002. El 100% de los pacientes presentaron sintomas gastrointestinales agudos, 7 niños presentaron insuficiencia renal aguda con acúfenos persistentes. Se efectuó diálisis peritoneal interminente precoz en todos ellos, con evolución favorable, sin secuelas renales ni óticas.


Asunto(s)
Niño , Lesión Renal Aguda , Acúfeno , Aditivos Alimentarios , Enfermedades Transmitidas por los Alimentos , Oxidantes , Potasio , Anamnesis , Diálisis Peritoneal
15.
Leukemia ; 17(10): 2016-24, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14513052

RESUMEN

Comparative genomic hybridization (CGH) studies have demonstrated a high incidence of chromosomal imbalances in non-Hodgkin's lymphoma. However, the information on the genomic imbalances in Burkitt's Lymphoma (BL) is scanty. Conventional cytogenetics was performed in 34 cases, and long-distance PCR for t(8;14) was performed in 18 cases. A total of 170 changes were present with a median of four changes per case (range 1-22). Gains of chromosomal material (143) were more frequent than amplifications (5) or losses (22). The most frequent aberrations were gains on chromosomes 12q (26%), Xq (22%), 22q (20%), 20q (17%) and 9q (15%). Losses predominantly involved chromosomes 13q (17%) and 4q (9%). High-level amplifications were present in the regions 1q23-31 (three cases), 6p12-p25 and 8p22-p23. Upon comparing BL vs Burkitt's cell leukemia (BCL), the latter had more changes (mean 4.3 +/- 2.2) than BL (mean 2.7 +/- 3.2). In addition, BCL cases showed more frequently gains on 8q, 9q, 14q, 20q, and 20q, 9q, 8q and 14q, as well as losses on 13q and 4q. Concerning outcome, the presence of abnormalities on 1q (ascertained either by cytogenetics or by CGH), and imbalances on 7q (P=0.01) were associated with a short survival.


Asunto(s)
Linfoma de Burkitt/genética , Aberraciones Cromosómicas , Cromosomas Humanos Par 1 , Cromosomas Humanos Par 7 , Adolescente , Adulto , Anciano , Linfoma de Burkitt/patología , Linfoma de Burkitt/terapia , Niño , Preescolar , Mapeo Cromosómico , Femenino , Humanos , Leucemia/genética , Masculino , Persona de Mediana Edad , Hibridación de Ácido Nucleico , Reacción en Cadena de la Polimerasa , Pronóstico , Translocación Genética , Resultado del Tratamiento
16.
Acta Otorrinolaringol Esp ; 53(7): 473-80, 2002.
Artículo en Español | MEDLINE | ID: mdl-12487069

RESUMEN

The nasopharyngeal carcinoma in Spain, low risk geographical area, is a rare tumor. This is the cause why there few papers about it in our country. We have carried out a muestral descriptive statistical study. We have selected among all the patients diagnosed of nasopharyngeal carcinoma a big group who, have been treated with induction chemotherapy followed by radiotherapy with or without surgery, they presented very complete clinical histories in the Departments of E.N.T., Oncology and Radiotherapy that allowed us to compare all the picked up data and this increased, without doubt, the reliability of them. The results obtained in the different examined variables of our patients are the same that those we found in literature. The nasopharyngeal carcinoma is a tumor that usually affects young patients, of both sexes, without previous consumption of alcohol and tobacco and they are diagnosed in advanced stages. The rhinologic symptoms are the most frequent ones but the cervical nodes are the usual cause for consulting a doctor with a long diagnostic interval. There is a prevalence in the undifferentiated tumors showed by histology.


Asunto(s)
Carcinoma , Neoplasias Nasofaríngeas , Adulto , Factores de Edad , Anciano , Consumo de Bebidas Alcohólicas/efectos adversos , Carcinoma/diagnóstico , Carcinoma/epidemiología , Carcinoma/mortalidad , Carcinoma/patología , Carcinoma/terapia , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/terapia , Terapia Combinada , Interpretación Estadística de Datos , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/epidemiología , Neoplasias Nasofaríngeas/mortalidad , Neoplasias Nasofaríngeas/patología , Neoplasias Nasofaríngeas/terapia , Nasofaringe/patología , Factores de Riesgo , Factores Sexuales , Fumar/efectos adversos , España/epidemiología , Factores de Tiempo
17.
Braz Dent J ; 12(3): 197-200, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11696918

RESUMEN

The aim of this in vitro study was to evaluate marginal leakage in class V restorations in primary teeth restored with amalgam, using three different techniques. Thirty maxillary anterior primary teeth, clinically sound and naturally exfoliated, were used. In group 1 (n = 10), two thin layers of a copal varnish (Cavitine) were applied. In group 2 (n = 10), Scotchbond Multi-Purpose Plus, a dual adhesive system, was used according to manufacturer instructions. In group 3 (n = 10), One-Step adhesive system in combination with a low-viscosity resin (Resinomer) were used according to manufacturer instructions. All samples were restored with a high-copper dental amalgam alloy (GS 80, SDI). After restoration, the samples were stored in normal saline at 37 degrees C for 72 h. The specimens were polished, thermocycled (500 cycles, 5 degrees and 55 degrees C, 30-s dwell time) and impermeabilized with fingernail polish to within 1.0 mm of the restoration margins. The teeth were then placed in 0.5% methylene blue for 4 h. Finally, the samples were sectioned and evaluated for marginal leakage. The Kruskal-Wallis test showed that the filled adhesive resin (group 3) had the least microleakage. There was no significant difference between groups 1 and 2.


Asunto(s)
Amalgama Dental , Recubrimiento Dental Adhesivo/métodos , Filtración Dental/prevención & control , Restauración Dental Permanente/métodos , Diente Primario , Resinas Compuestas , Recubrimiento de la Cavidad Dental , Materiales Dentales , Recubrimientos Dentinarios , Humanos , Incisivo , Maxilar , Metacrilatos , Cementos de Resina , Resinas de Plantas , Estadísticas no Paramétricas
18.
Am J Pathol ; 158(5): 1843-50, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11337382

RESUMEN

Splenic marginal zone lymphoma (SMZL) has recently been recognized in the World Health Organization classification of hematological diseases as distinct type of non-Hodgkin's lymphoma. In contrast to the well-established chromosomal changes associated with other B-cell non-Hodgkin's lymphoma, few genetic alterations have been found associated with SMZL. The aim of our study was to analyze by comparative genomic hybridization (CGH) the chromosomal imbalances in 29 patients with SMZL and to correlate these findings with clinical and biological characteristics and patient outcome. In 21 cases, cytogenetic studies were simultaneously performed. Most of the patients (83%) displayed genomic imbalances. A total of 111 DNA copy number changes were detected with a median of four abnormalities per case (range, 1 to 12). Gains (n = 92) were more frequent than losses (n = 16), while three high-level amplifications (3q26-q29, 5p11-p15, and 17q22-q25) were observed. The most frequent gains involved 3q (31%), 5q (28%), 12q and 20q (24% each), 9q (21%), and 4q (17%). Losses were observed in 7q (14%) and 17p (10%). SMZL patients with genetic losses had a shorter survival than the remaining SMZL patients (P < 0.05). In summary, chromosomal imbalances in regions 3q, 4q, 5q, 7q, 9q, 12q, and 20q have been detected by CGH in SMZL. Patients with SMZL displaying genetic losses by CGH had a short survival.


Asunto(s)
Aberraciones Cromosómicas , Linfoma de Células B/genética , Neoplasias del Bazo/genética , Adulto , Anciano , Análisis Citogenético , Femenino , Humanos , Cariotipificación , Linfoma de Células B/patología , Masculino , Persona de Mediana Edad , Hibridación de Ácido Nucleico , Neoplasias del Bazo/patología , Análisis de Supervivencia
19.
Exp Neurol ; 167(1): 108-17, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11161598

RESUMEN

Previous studies of neural xenografts have used immunosuppressive agents to prevent graft rejection. In the present study we have examined the survival of mouse dopamine neurons lacking either MHC class I or MHC class II molecules transplanted into rat brains and the host immune and inflammatory responses against the xenografts. Survival of neural grafts was immunocytochemically determined at 4 days, 2 weeks, and 6 weeks after transplantation by counting tyrosine hydroxylase (TH)-positive cells in the graft areas. In addition, the host immune and inflammatory responses against neural xenografts were evaluated by semiquantitatively rating MHC class I and class II antigen expression, accumulation of macrophages and activated microglia, and infiltration of CD4- and CD8-positive T-lymphocytes. For the negative controls, the mean number of TH-positive cells in rats that received wild-type mouse tissue progressively decreased at various time periods following transplantation. In contrast, intrastriatal grafting of either MHC class I or MHC class II antigen-depleted neural xenografts resulted in a prolonged survival and were comparable to cyclosporin A-treated rats that had received wild-type mouse tissue. These results indicate that genetically modified donor tissue lacking MHC molecules can be used to prevent neural xenograft rejection.


Asunto(s)
Cuerpo Estriado/citología , Dopamina/metabolismo , Supervivencia de Injerto/inmunología , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase I/genética , Neuronas/trasplante , Animales , Trasplante de Tejido Encefálico/inmunología , Linfocitos T CD4-Positivos/citología , Linfocitos T CD8-positivos/citología , Cuerpo Estriado/cirugía , Ciclosporina/farmacología , Trasplante de Tejido Fetal , Antígenos de Histocompatibilidad Clase I/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Inmunohistoquímica , Antígeno de Macrófago-1/metabolismo , Mesencéfalo/citología , Mesencéfalo/embriología , Mesencéfalo/trasplante , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/citología , Neuronas/metabolismo , Ratas , Ratas Sprague-Dawley , Trasplante Heterólogo/inmunología , Tirosina 3-Monooxigenasa/metabolismo
20.
Lupus ; 9(8): 584-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11035432

RESUMEN

The objective was to analyze psychiatric disorders and psychosocial dysfunction in patients with systemic lupus erythematosus (SLE), studied longitudinally during active and subsequent inactive stage of their disease. During a 6 month period of study, we selected 20 consecutive patients with SLE who presented with a SLE flare. All patients fulfilled the 1982 revised criteria of the American College of Rheumatology for the classification of SLE. When patients entered the study, we performed psychiatric (CIS, RDC, STAI, HD, BDI, GHQ and MMS) psychosocial (GAS and VAS-P) scores assessment. One year later, we repeated the psychiatric and psychosocial assessment when patients showed inactive disease. The 20 patients evaluated were women, with a mean age of 34 y (SE 14.4, range 20-57). According to CIS evaluation, we diagnosed 8 (40%) psychiatric cases in the acute episode of SLE. The RDC diagnosis showed generalized anxiety in 5 patients, panic disorders in 2 patients and generalized anxiety plus depressive symptoms in one patient. One year later, when patients did not show disease activity, we diagnosed 2 (10%) psychiatric cases (P<0.05). When SLE patients were clinically inactive, they showed lower levels of psychological distress (GHQ scale, 1.8 vs 5.6, P<0.001), with a lower grade of anxiety measured by both HA (3.2 vs 8.2, P<0.01) and STAI-S (7.95 vs 20.90, P<0.001) scales. We also found a lower score in pain perception (VAS-P) (2.80 vs 4.25, P<0. 01) and higher occupational activity (VAS-P) (83.9 vs 66.2, P<0.01) and general functioning (GAS) (93.75 vs 83.50, P<0.05) during the inactive stage. No significant differences were found when we compared cognitive impairment, grade of depression and physical disability between inactive and active stages. We conclude that in SLE patients, psychiatric and psychosocial disorders during acute episodes are usually mild and seem to be related to the psychological impact of disease activity on patients. This type of psychiatric pathology is similar to that which would be expected in other groups coping with a stressful event, indicating that our patients did not react in a way specifically determined by their systemic disease.


Asunto(s)
Lupus Eritematoso Sistémico/psicología , Escalas de Valoración Psiquiátrica , Adulto , Anticuerpos Antinucleares/sangre , Ansiedad/diagnóstico , Trastornos del Conocimiento/diagnóstico , Trastorno Depresivo/diagnóstico , Evaluación de la Discapacidad , Femenino , Indicadores de Salud , Humanos , Estudios Longitudinales , Lupus Eritematoso Sistémico/fisiopatología , Persona de Mediana Edad , Trastorno de Pánico/diagnóstico
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