Persistencia del herbicida Imazapir en el suelo y efectos fitotóxicos sobre cultivos de invierno y de verano

Imazapir es un herbicida de amplio espectro de control, perteneciente al grupo químico de las imidazolinonas. En Argentina es aplicado a gran escala en los cultivos de girasol y maíz Clearfield. Debido a su acción residual en el suelo, resulta de gran importancia determinar su persistencia fitotóxica. El objetivo de este trabajo fue determinar la persistencia fitotóxica sobre cultivos de invierno y de verano, de dos dosis de imazapir aplicado en un cultivo de girasol Clearfield. El ensayo se realizó en un suelo franco-arcilloso de Balcarce (Pcia. de Buenos Aires), siguiendo un diseño experimental en bloques completos aleatorizados con cuatro repeticiones. Los tratamientos consistieron en la aplicación de imazapir en dosis de 80 y 160 g de ingrediente activo (i.a)/ha, incluyéndose un testigo sin tratar. Luego de la cosecha del girasol (marzo de 2003), se obtuvieron muestras de suelo mensualmente. Posteriormente, se efectúo un bioensayo en cámara de crecimiento con trigo, colza, girasol y maíz no tolerantes. Paralelamente, se sembró a campo maíz y girasol no tolerantes a imidazolinonas y papa, determinándose el rendimiento. Los resultados fueron analizados mediante un análisis de la varianza (p = 0.05). La persistencia fitotóxica en el bioensayo siguió el orden trigo > colza > girasol = maíz. A campo, ninguno de los cultivos evaluados mostró efectos negativos, indicando que no existió efecto residual sobre ellos

Análise da disponibilidade hídrica para a cultura da soja nas safras 2004/05 e 2009/10 em Londrina, PR.

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Teor relativo de água em cultivares de soja sob três níveis de disponibilidade hídrica no solo.

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Avaliação do fluxo de seiva em cultivares de soja em três níveis de disponibilidade hídriva no solo.

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Loss of function and reduced levels of sphingolipid desaturase DEGS1 variants are both relevant in disease mechanism

The last step of ex novo ceramide biosynthesis consists of the conversion of dihydroceramide into ceramide catalyzed by sphingolipid Δ4-desaturase DEGS1. DEGS1 variants were found to be responsible for heterogeneous clinical pictures belonging to the family of hypomyelinating leukodystrophies. To investigate the mechanisms making such variants pathogenic, we designed a procedure for the efficient detection of desaturase activity in vitro using LC-MS/MS and prepared a suitable cell model knocking out DEGS1 in HEK-293T cells through CRISPR-Cas9 genome editing (KO-DES-HEK). Transfecting KO-DES-HEK cells with DEGS1 variants, we found that their transcripts were all overexpressed as much as the WT transcripts, while the levels of cognate protein were 40%-80% lower. In vitro desaturase activity was lost by many variants except L175Q and N255S, which maintain a catalytic efficiency close to 12% of the WT enzyme. Metabolic labeling of KO-DES-HEK with deuterated palmitate followed by LC-MS/MS analysis of the formed sphingolipids revealed that the ceramide/dihydroceramide and sphingomyelin/dihydrosphingomyelin ratios were low and could be reverted by the overexpression of WT DEGS1 as well as of L175Q and N255S variants, but not by the overexpression of all other variants. Similar analyses performed on fibroblasts from a patient heterozygous for the N255S variant showed very low variant DEGS1 levels and a low ratio between the same unsaturated and saturated sphingolipids formed upon metabolic labeling, notwithstanding the residual activity measured at high substrate and homogenate protein concentrations. We conclude that loss of function and reduced protein levels are both relevant in disease pathogenesis

Índice de vegetação por diferença normalizada (NDVI) de cultivares de soja sob três níveis de disponibilidade hídirca no solo.

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Acute myeloid leukemia and pregnancy: Clinical experience from a single center and a review of the literature

Background: Acute myeloid leukemia (AML) accounts for more than two thirds of leukemia during pregnancy and has an incidence of 1 in 75,000 to 100,000. Its clinical management remains a challenging therapeutic task both for patient and medical team, given to the therapy-attributable risks for mother and fetus and the connected counseling regarding pregnancy continuation. Methods: We provided a review of updated literature and a comprehensive description of five maternal/fetal outcomes of AML cases diagnosed concomitantly to pregnancy and treated at our Institution from 2006 to 2012. Results: Median age at AML diagnosis was 32 years (31-39). One diagnosis was performed in first trimester and the patient asked for therapeutic abortion before starting chemotherapy. Three cases were diagnosed in second/third trimester; in one case leukemia was diagnosed concomitantly with intrauterine fetal death, while the remaining two patients continued pregnancy and delivered a healthy baby by cesarean section. In only one of these two cases chemotherapy was performed during pregnancy (at 24 + 5 weeks) and consisted of a combination of daunorubicine and cytarabine. Therapy was well tolerated and daily fetus monitoring was performed. After completion of 30 weeks of gestation a cesarean section was carried out; the newborn had an Apgar score of 5/1'-7/5'-9/10', oxygen therapy was temporarily given and peripheral counts displayed transient mild leukopenia. One patient had diagnosis of myelodysplastic syndrome rapidly progressed to AML after delivery. Four out of the 5 described women are currently alive and disease-free. Three children were born and long-term follow-up has shown normal growth and development. Conclusions: The treatment of AML occurring during pregnancy is challenging and therapeutic decisions should be taken individually for each patient. Consideration must be given both to the immediate health of mother and fetus and to long-term infant health. Our series confirmed the literature data: fetal toxicity of cytostatic therapy clusters during the first trimester; while chemotherapy can be administered safely during second/third trimester and combination of daunorubicin and cytarabine is recommended for induction

Reproducibility of the WHO histological criteria for the diagnosis of Philadelphia chromosome-negative myeloproliferative neoplasms.

This study, performed on behalf of the Italian Registry of Thrombocythaemias (Registro Italiano Trombocitemie), aimed to test the inter-observer reproducibility of the histological parameters proposed by the WHO classification for the diagnosis of the Philadelphia chromosome-negative myeloproliferative neoplasms. A series of 103 bone marrow biopsy samples of Philadelphia chromosome-negative myeloproliferative neoplasms consecutively collected in 2004 were classified according to the WHO criteria as follows: essential thrombocythaemia (n=34), primary myelofibrosis (n=44) and polycythaemia vera (n=25). Two independent groups of pathologists reviewed the bone marrow biopsies. The first group was asked to reach a collegial 'consensus' diagnosis. The second group reviewed individually all the cases to recognize the main morphological parameters indicated by the WHO classification and report their results in a database. They were subsequently instructed to individually build a 'personal' diagnosis of myeloproliferative neoplasms subtype just assembling the parameters collected in the database. Our results indicate that high levels of agreement ( 6570%) have been reached for about all of the morphological features. Moreover, among the 18 evaluated histological features, 11 resulted statistically more useful for the differential diagnosis among the different Philadelphia chromosome-negative myeloproliferative neoplasms. Finally, we found a high percentage of agreement (76%) between the 'personal' and 'consensus' diagnosis (Cohen's kappa statistic >0.40). In conclusion, our results support the use of the histological criteria proposed by the WHO classification for the Philadelphia chromosome-negative myeloproliferative neoplasms to ensure a more precise and early diagnosis for these patients

Prognostic relevance of serum beta2 microglobulin in patients with follicular lymphoma treated with anthracycline-containing regimens. A GISL study.

Background and ObjectivesAlthough serum b2 microglobulin (b2M) is an easy parameter to measure, and overexpressedin a large number of lymphoproliferative diseases, its prognostic value hasbeen largely underestimated. The present study examined the influence of b2M levelson overall survival (OS) of patients with follicular lymphoma (FL).Design and MethodsThe prognostic role of b2M was evaluated in 236 patients with FL identified from thedatabases of the Gruppo Italiano per lo Studio dei Linfomi (GISL) and treated withanthracycline-based regimens from 1993 to 2003.ResultsElevated serum b2M levels were found in 82 patients (35%). According to multivariatelogistic regression analysis, elevated b2M levels were associated with elevatedlactate dehydrogenase (LDH) (p=0.021), age (p=0.029), and number of involvednodal areas (p<0.001). The percentage of elevated b2M levels increased progressivelywith increasing FLIPI scores (17%, 38%, and 63% in the low-, intermediate-, andhigh-risk groups, respectively). Five-year OS was 61% (95% CI, 47-73%) and 89% (95%CI, 82-93%) for patients with elevated vs normal b2M levels respectively (p<0.001).Cox regression analysis showed that b2M level had an independent and stable prognosticvalue (HR=3.0; 95%CI, 1.6-5.7). In a multivariate analysis the impact of b2Mlevel on survival was independent of FLIPI score, with a HR of 2.94 (95% CI, 1.54-5.62).Interpretation and ConclusionsOur results demonstrate that in patients treated in the pre-rituximab era, b2M levelwas an independent prognostic marker in addition to FLIPI score. We thus suggestthat b2M be routinely assessed and tested in future prognostic studies of FL patientstreated with combination chemotherapy and anti-CD20 agents