12 research outputs found
Novel Proangiogenic Effect of Factor XIII Associated With Suppression of Thrombospondin 1 Expression
Anisotropic magnetic particles in a magnetic field
We characterize the structural properties of magnetic ellipsoidal hematite colloids with an aspect ratio Ļ ā 2.3 using a combination of small-angle X-ray scattering and computer simulations. The evolution of the phase diagram with packing fraction Ļ and the strength of an applied magnetic field B is described, and the coupling between orientational order of magnetic ellipsoids and the bulk magnetic behavior of their suspension addressed. We establish quantitative structural criteria for the different phase and arrest transitions and map distinct isotropic, polarized non-nematic, and nematic phases over an extended range in the Ļ-B coordinates. We show that upon a rotational arrest of the ellipsoids around Ļ = 0.59, the bulk magnetic behavior of their suspension switches from superparamagnetic to ordered weakly ferromagnetic. If densely packed and arrested, these magnetic particles thus provide persisting remanent magnetization of the suspension. By exploring structural and magnetic properties together, we extend the often used colloid-atom analogy to the case of magnetic spins
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Leiomyoma With Bizarre Nuclei: A Morphological, Immunohistochemical and Molecular Analysis of 31 Cases
Leiomyomas associated with hereditary leiomyomatosis and renal cell carcinoma syndrome and leiomyomas with bizarre nuclei often show overlapping morphological features, in particular cells with prominent eosinophilic nucleoli, perinucleolar halos and eosinophilic cytoplasmic inclusions. While hereditary leiomyomatosis and renal cell carcinoma syndrome is defined by fumarate hydratase (FH) germline mutations, resulting in S-(2-succino)-cysteine (2SC) formation, it is unknown if leiomyomas with bizarre nuclei show similar alterations. In this study, we evaluated the morphology and FH/2SC immunoprofile of 31 leiomyomas with bizarre nuclei. DNA from tumor and normal tissues from 24 cases was subjected to massively parallel sequencing targeting 410 key cancer genes. Somatic genetic alterations were detected using state-of-the-art bioinformatics algorithms. No patient reported a personal history of renal neoplasia or cutaneous leiomyomas, but one had a family history of renal cell carcinoma while another had a family history of uterine leiomyomas. Aberrant FH/2SC expression was noted in 17 tumors (16 FH-negative/2SC-positive, 1 FH-positive/2SC-positive). On univariate analysis, staghorn vessels, eosinophilic cytoplasmic inclusions, diffuse distribution of prominent eosinophilic nucleoli with perinucleolar halos and an āalveolar pattern of edemaā were associated with an abnormal immunoprofile, but only staghorn vessels remained significant on multivariate analysis. Massively parallel sequencing analysis (n=24) revealed that 13/14 tumors with aberrant FH/2SC immunoprofile harbored somatic FH somatic genetic alterations, including homozygous deletions (n=9), missense mutations coupled with loss of heterozygosity (n=3), and a splice site mutation (n=1), whereas no somatic FH mutations/deletions were found in tumors with normal immunoprofile (n=10; p<0.0001). Leiomyomas with bizarre nuclei with normal FH/2SC staining pattern more frequently harbored TP53 and/or RB1 alterations than those with aberrant FH/2SC immunoprofile (60% vs 14%; p=0.032). These data demonstrate that leiomyomas with bizarre nuclei are morphologically and genetically heterogeneous, and that hereditary leiomyomatosis and renal cell carcinoma syndrome-related morphologic features, abnormal FH/2SC staining, and somatic FH mutations/deletions can be seen in a subset of sporadic tumors