Charge Fluctuations on Membrane Surfaces in Water

We generalize the predictions for attractions between over-all neutral surfaces induced by charge fluctuations/correlations to non-uniform systems that include dielectric discontinuities, as is the case for mixed charged lipid membranes in an aqueous solution. We show that the induced interactions depend in a non-trivial way on the dielectric constants of membrane and water and show different scaling with distance depending on these properties. The generality of the calculations also allows us to predict under which dielectric conditions the interaction will change sign and become repulsive

The spectrum of myelodysplastic syndromes post-solid organ transplantation: A single institutional experience

An increased incidence of acute myeloid leukemia (AML) has recently been documented in patients post-solid organ transplantation but the incidence and types of myelodysplastic syndromes (MDS) occurring in this patient population are not known. We identified 5 patients (3M, 2F, age 48–64 years) who developed MDS ranging from 1.8 to 25 years (median 4.2 years) post-solid organ transplantation, only 2 patients had received azathioprine. The cumulative incidence of MDS in heart and lung transplant recipients at 15 years was 0.5% and 1.8%, respectively, which is markedly higher compared to the general population. Low-risk types of MDS predominated, 3 of 5 patients are alive (median 3.9 years) since diagnosis. Deletions of chromosome 20q, which have not been previously reported in post-transplant MDS/AML, were identified in 3 cases. Our findings expand the morphologic and cytogenetic spectrum of MDS occurring post-solid organ transplantation and suggest that mechanisms beside azathioprine toxicity might be important in disease pathogenesis

Atypical ductal hyperplasia is a multipotent precursor of breast carcinoma

The current model for breast cancer progression proposes independent “low‐grade (LG) like” and “high‐grade (HG) like” pathways but lacks a known precursor to HG cancer. We applied low coverage whole genome sequencing to atypical ductal hyperplasia (ADH) with and without carcinoma to shed light on breast cancer progression. 14/20 isolated ADH cases harboured at least one copy number alteration (CNA), but had fewer aberrations than LG or HG ductal carcinoma in situ (DCIS). ADH carried more HG‐like CNA than LG DCIS (eg. 8q gain). Correspondingly, 64% (7/11) of ADH cases with synchronous HG carcinoma were clonally related, similar to LG carcinoma (67%, 6/9). This study represents a significant shift in our understanding of breast cancer progression, with ADH as a common precursor lesion to the independent “low‐grade like” and “high‐grade like” pathways. These data suggest that ADH can be a precursor of HG breast cancer and that LG and HG carcinomas can evolve from a similar ancestor lesion. We propose that although LG DCIS may be committed to a LG molecular pathway, ADH may remain multipotent, progressing to either LG or HG carcinoma. This multipotent nature suggests that some ADH could be more clinically significant than LG DCIS, requiring biomarkers for personalising management

Efecto de la estructura del suelo sobre el desarrollo radical del maíz con dos sistemas de labranza

La estructura del suelo (arreglo geométrico y topológico de los poros del suelo que se forman entre los agregados, y su estabilidad en tiempo y espacio) es una propiedad básica considerada como uno de los principales atributos de la calidad del suelo. En este estudio se analizaron dos sistemas de labranza de largo plazo bajo riego: tradicional (LT) y de conservación (LC), con especial énfasis en el comportamiento de propiedades como densidad aparente (ñb), la pendiente de la curva de retención de humedad en su punto de inflexión (S) y contenido de materia orgánica (MO), así como su relación con el sistema radical del maíz (Zea mays). Se efectuaron pruebas comparativas considerando algunos parámetros de suelo (ñb, MO, y S) y planta (biomasa, y longitud de raíz). Los resultados muestran que los parámetros ñb, MO y S utilizados para medir la calidad física del suelo, demostraron que los sistemas de labranza causan cambios en la estructura del mismo y por ende en su calidad. El sistema de LC propicia una mejor calidad e incrementa el contenido de MO en el suelo. Los valores de S son menores en LT, lo que indica que tiene menor capacidad de retener agua en comparación con LC. Se encontró una alta correlación entre S y longitud de raíz, significativa al agrupar los datos de acuerdo con el tipo de manejo. Por tanto, S se podría usar como un indicador para evaluar el impacto de las prácticas agrícolas sobre la calidad del suelo