System-, teacher-, and student-level interventions for improving participation in online learning at scale in high schools.

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.

Laser-induced breakdown spectroscopy determination of toxic metals in fresh fish.

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.

Gastroduodenitis eosinofilica: a propósito de un caso / EOSINOPHILIC GASTRODUODENITIS: CASE REPORT

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.

Fisioterapia respiratoria / No disponible

No disponible

Cultura de seguridad del paciente en residentes de medicina familiar y comunitaria de Aragón / Patient safety culture in family and community medicine residents in Aragon

Introducción: Una adecuada cultura de seguridad del paciente es la primera recomendación para mejorar la misma. El objetivo fue conocer la cultura de seguridad del paciente (SP) en los residentes de medicina familiar y comunitaria para identificar estrategias de mejora. Métodos: Encuesta transversal online dirigida a los residentes de las unidades docentes de medicina de familiar y comunitaria de Aragón. Se utilizó el cuestionario Medical Office Survey on Patient Safety Culture (MOSPS) traducido, validado y adaptado al español. Para el análisis de los resultados se agruparon las respuestas en 12 dimensiones y se calculó el valor medio de cada dimensión. Las percepciones se describieron mediante los porcentajes de respuestas positivas (PRP) y negativas (PRN) de cada dimensión. Resultados: Se observaron resultados positivos en el «seguimiento de la atención a los pacientes» y el «trabajo en equipo». Se apreciaron diferencias significativas en las dimensiones «intercambio de información con otros dispositivos asistenciales», «formación del personal» y «percepciones generales sobre la SP y la calidad». Los participantes del estudio valoraron negativamente el «ritmo y carga de trabajo». Conclusiones: Las instituciones prestadoras de servicios de salud y su personal son cada vez más conscientes de la importancia de mejorar la SP, y los resultados de este estudio permitieron mostrar información que ayuda a identificar debilidades para diseñar iniciativas y estrategias y establecer mejoras de las prácticas asistenciales (AU)

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-up». There were significant differences in the «Information Exchange With Other Settings», «Staff Training» and «Overall Perceptions of Patient Safety and Quality». Study participants viewed «Work Pressure and Pace» 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

[Patient safety culture in family and community medicine residents in Aragon]. / Cultura de seguridad del paciente en residentes de medicina familiar y comunitaria de Aragón.

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.

Modulation of Ca2+-currents by sequential and simultaneous activation of adenosine A1 and A 2A receptors in striatal projection neurons.

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.

Kikuchi-Fujimoto disease: a case supporting a role for human herpesvirus 7 involvement in the pathogenesis.

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.

Genetic and morphological variability in South American rodent Oecomys (Sigmodontinae, Rodentia): evidence for a complex of species.

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.

Impacto de la dieta sobre la proteinuria en pacientes con nefropatía secuelar por sindrome urémico hemolítico (D+) / Impact of the diet on proteinuria in patients with sequelae nephorapathy due t o Hemolytic Uremic Syndrome (D+)

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.

Sustained leukaemic phenotype after inactivation of BCR-ABLp190 in mice.

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.

[Rapid recurrence of ANCA-MPO positive vasculitis after non-heart beating donor renal transplantation]. / Recurrencia rápida de una vasculitis ANCA-MPO positivo tras trasplante renal de donante en asistolia.

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.

SLUG (SNAI2) overexpression in embryonic development.

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.

Hiperandrogenismo / Hyperandrogenism

El hiperandrogenismo es un problema endocrinológico frecuente en mujeres adultas. Su manifestación más habitual es el hirsutismo, acompañado o no de trastornos menstruales y con menor frecuencia de virilización. Se presenta un caso clínico de hiperandrogenismo con amenorrea secundaria y virilización en una mujer en edad fértil. Se evalúa el papel de las diferentes determinaciones hormonales y técnicas de imagen en el diagnóstico etiológico de este cuadro

Hyperandrogenism is one of the most common endocrine diseases affecting adult women. Clinical presentation includes hirsutism, with or without menstrual disturbances (oligomenorrhea, amenorrhea) and, less frequently, virilization. We report the case of a woman of reproductive age with hyperandrogenism, secondary amenorrhea, and virilization. The diagnostic role of laboratory tests and imaging techniques is discussed

Recurrencia rápida de una vasculitis ANCA-MPO positivo tras trasplante renal de donante en asistolia / Rapid recurrence of ANCA-MPO positive vasculitis after non-heart beating donor renal transplantation

Publicamos un caso de un paciente con insuficiencia renal avanzada con lesionescompatibles con vasculitis renal asociada a anticuerpos contra citoplasmade neutrófilos (ANCA) en fase de esclerosis que recibió un injerto renal de cadáveren asistolia tras un año en programa de hemodiálisis con ausencia de sintomatologíavasculítica. El tratamiento inmunosupresor se realizó acorde a nuestroprotocolo en este tipo de donantes basado en daclizumab, dosis media detacrolimus, micofenolato mofetil y esteroides.En la tercera semana post-trasplante la biopsia renal mostró una glomerulonefritisnecrotizante con semilunas. El paciente fue inicialmente diagnosticado de rechazoagudo vascular y recibió tratamiento con 6-metilprednisolona y anticuerposmonoclonales anti-CD3. Dos días más tarde el paciente desarrolló una púrpuracutánea cuya biopsia mostró una vasculitis aguda necrotizante. La determinaciónde ANCA circulante anti mieloperoxidasa (MPO) fue positiva. Se inició tratamientocon ciclofosfamida oral retirándose el micofenolato mofetil, con rápida desapariciónde las lesiones purpúricas y mejoría de la función renal

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

Recurrencia rápida de una vasculitis ANCA-MPO positivo tras trasplante renal de donante en asistolia / Rapid recurrence of ANCA-MPO positive vasculitis after non-heart beating donor renal transplantation

Publicamos un caso de un paciente con insuficiencia renal avanzada con lesiones compatibles con vasculitis renal asociada a anticuerpos contra citoplasma de neutrófilos (ANCA) en fase de esclerosis que recibió un injerto renal de cadáver en asistolia tras un año en programa de hemodiálisis con ausencia de sintomatología vasculítica. El tratamiento inmunosupresor se realizó acorde a nuestro protocolo en este tipo de donantes basado en daclizumab, dosis media de tacrolimus, micofenolato mofetil y esteroides. En la tercera semana post-trasplante la biopsia renal mostró una glomerulonefritis necrotizante con semilunas. El paciente fue inicialmente diagnosticado de rechazo agudo vascular y recibió tratamiento con 6-metilprednisolona y anticuerpos monoclonales anti-CD3. Dos días más tarde el paciente desarrolló una púrpura cutánea cuya biopsia mostró una vasculitis aguda necrotizante. La determinación de ANCA circulante anti mieloperoxidasa (MPO) fue positiva. Se inició tratamiento con ciclofosfamida oral retirándose el micofenolato mofetil, con rápida desaparición de las lesiones purpúricas y mejoría de la función renal

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 inmurenal 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

Structure and environmental relationships of insectivorous bat assemblages in tropical Australian savannas.

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.

Intoxicación con bromato de potasio en una escuela / Potassium bromide intoxication in a school

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.

Abnormalities on 1q and 7q are associated with poor outcome in sporadic Burkitt's lymphoma. A cytogenetic and comparative genomic hybridization study.

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.