219 research outputs found

    Whole-body magnetic resonance imaging (WB-MRI) in lymphoma: State of the art

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    The improvements in magnetic resonance imaging (MRI) technology and the concern related to the increased cancer risk in patients with lymphoma, also due to radiation exposure associated with imaging examinations, have led to the introduction of whole-body MRI (WB-MRI) as a radiation-free alternative to standard imaging procedures. WB-MRI seems a less histology-dependent functional imaging test than 18F-fluorodeoxyglucose-positron emission tomography/CT (18F-FDG-PET/CT). In patients with FDG-avid lymphomas, such as diffuse large B-cell lymphoma (DLBCL) and Hodgkin lymphoma (HL), 18F-FDG-PET/CT remains the imaging reference standard for staging, with WB-MRI potentially being a complementary modality that could replace CT, especially in young patients. On the other hand, WB-MRI is a valuable imaging procedure for lymphoma surveillance and in lymphomas with variable/low FDG avidity and nonfollicular indolent lymphomas. The aim of this paper is to discuss the current state of the art of WB-MRI in lymphoma by evaluating its diagnostic performance in different lymphoma subtypes: Hodgkin, aggressive, and indolent lymphomas

    Resonant electron transmission through a finite quantum spin chain

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    Electron transport in a finite one dimensional quantum spin chain (with ferromagnetic exchange) is studied within an sβˆ’ds-d exchange Hamiltonian. Spin transfer coefficients strongly depend on the sign of the sβˆ’ds-d exchange constant. For a ferromagnetic coupling, they exhibit a novel resonant pattern, reflecting the salient features of the combined electron-spin system. Spin-flip processes are inelastic and feasible at finite voltage or at finite temperature.Comment: 4 pages including 4 .eps figure

    Effect of tree presence and soil characteristics on soybean yield and quality in an innovative alley-cropping system

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    Agroforestry is indicated as a farming practice suited to enhance ecosystem services generated by cropping systems. However, farmers are often reluctant to implement agroforestry systems due to the potential yield loss of crops. In a field trial, soybean was intercropped with poplar short-rotation-coppice rows in an alley-cropping system with 13.5 m wide alleys, in order to assess the effect of tree presence on soybean yield and quality. The light availability (LA) was significantly affected by the tree presence, with an increasing effect along the season due to tree growth, being at its lowest in the tree–crop interface positions (West and East). Significant effects of the tree-distance and LA were registered on soybean yield, with the highest reduction of soybean yield in the West (βˆ’78%) and East (βˆ’35%) positions. Crude fat content in soybean grain did not vary among positions in the alley, while crude protein content was the lowest in the most shaded position (West βˆ’8% than the highest value). The assessment of spatial variability among plots of measured soil characteristics highlighted no significant effect of pedological conditions upon soybean yield. Thus, in our study, the LA effect was more important than soil characteristics in determining a detrimental effect of competition for resources between soybean and poplar. Conversely, soybean quality was affected by soil characteristics, since crude fat significantly correlated with soil nutrients, pH, soil organic matter and soil texture

    Tumor Spreading to the Contralateral Ovary in Bilateral Ovarian Carcinoma Is a Late Event in Clonal Evolution

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    Cancer of the ovary is bilateral in 25%. Cytogenetic analysis could determine whether the disease in bilateral cases is metastatic or two separately occurring primary tumors, but karyotypic information comparing the two cancerous ovaries is limited to a single report with 11 informative cases. We present a series of 32 bilateral ovarian carcinoma cases, analyzed by karyotyping and high-resolution CGH. Our karyotypic findings showed that spreading to the contralateral ovary had occurred in bilateral ovarian cancer cases and that it was a late event in the clonal evolution of the tumors. This was confirmed by the large number of similar changes detected by HR-CGH in the different lesions from the same patient. The chromosomal bands most frequently involved in structural rearrangements were 19p13 (n = 12) and 19q13 (n = 11). The chromosomal bands most frequently gained by both tumorous ovaries were 5p14 (70%), 8q23-24 (65%), 1q23-24 (57%), and 12p12 (48%), whereas the most frequently lost bands were 17p11 (78%), 17p13 (74%), 17p12 (70%), 22q13 (61%), 8p21 and 19q13 (52%), and 8p22-23 (48%). This is the first time that 5p14 is seen gained at such a high frequency in cancer of the ovary; possibly oncogene(s) involved in bilateral ovarian carcinogenesis or tumor progression may reside in this band

    DNA methylation profiling of ovarian carcinomas and their in vitro models identifies HOXA9, HOXB5, SCGB3A1, and CRABP1 as novel targets

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    <p>Abstract</p> <p>Background</p> <p>The epigenetics of ovarian carcinogenesis remains poorly described. We have in the present study investigated the promoter methylation status of 13 genes in primary ovarian carcinomas (n = 52) and their <it>in vitro </it>models (n = 4; ES-2, OV-90, OVCAR-3, and SKOV-3) by methylation-specific polymerase chain reaction (MSP). Direct bisulphite sequencing analysis was used to confirm the methylation status of individual genes. The MSP results were compared with clinico- pathological features.</p> <p>Results</p> <p>Eight out of the 13 genes were hypermethylated among the ovarian carcinomas, and altogether 40 of 52 tumours were methylated in one or more genes. Promoter hypermethylation of <it>HOXA9</it>, <it>RASSF1A</it>, <it>APC</it>, <it>CDH13</it>, <it>HOXB5</it>, <it>SCGB3A1 (HIN-1)</it>, <it>CRABP1</it>, and <it>MLH1 </it>was found in 51% (26/51), 49% (23/47), 24% (12/51), 20% (10/51), 12% (6/52), 10% (5/52), 4% (2/48), and 2% (1/51) of the carcinomas, respectively, whereas <it>ADAMTS1</it>, <it>MGMT</it>, <it>NR3C1</it>, <it>p14</it><sup><it>ARF</it></sup>, and <it>p16</it><sup><it>INK</it>4<it>a </it></sup>were unmethylated in all samples. The methylation frequencies of <it>HOXA9 </it>and <it>SCGB3A1 </it>were higher among relatively early-stage carcinomas (FIGO I-II) than among carcinomas of later stages (FIGO III-IV; <it>P </it>= 0.002, <it>P </it>= 0.020, respectively). The majority of the early-stage carcinomas were of the endometrioid histotype. Additionally, <it>HOXA9 </it>hypermethylation was more common in tumours from patients older than 60 years of age (15/21) than among those of younger age (11/30; <it>P </it>= 0.023). Finally, there was a significant difference in <it>HOXA9 </it>methylation frequency among the histological types (<it>P </it>= 0.007).</p> <p>Conclusion</p> <p>DNA hypermethylation of tumour suppressor genes seems to play an important role in ovarian carcinogenesis and <it>HOXA9</it>, <it>HOXB5</it>, <it>SCGB3A1</it>, and <it>CRABP1 </it>are identified as novel hypermethylated target genes in this tumour type.</p

    Genomic aberrations in borderline ovarian tumors

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    <p>Abstract</p> <p>Background</p> <p>According to the scientific literature, less than 30 borderline ovarian tumors have been karyotyped and less than 100 analyzed for genomic imbalances by CGH.</p> <p>Methods</p> <p>We report a series of borderline ovarian tumors (n = 23) analyzed by G-banding and karyotyping as well as high resolution CGH; in addition, the tumors were analyzed for microsatellite stability status and by FISH for possible 6q deletion.</p> <p>Results</p> <p>All informative tumors were microsatellite stable and none had a deletion in 6q27. All cases with an abnormal karyotype had simple chromosomal aberrations with +7 and +12 as the most common. In three tumors with single structural rearrangements, a common breakpoint in 3q13 was detected. The major copy number changes detected in the borderline tumors were gains from chromosome arms 2q, 6q, 8q, 9p, and 13q and losses from 1p, 12q, 14q, 15q, 16p, 17p, 17q, 19p, 19q, and 22q. The series included five pairs of bilateral tumors and, in two of these pairs, informative data were obtained as to their clonal relationship. In both pairs, similarities were found between the tumors from the right and left side, strongly indicating that bilaterality had occurred via a metastatic process. The bilateral tumors as a group showed more aberrations than did the unilateral ones, consistent with the view that bilaterality is a sign of more advanced disease.</p> <p>Conclusion</p> <p>Because some of the imbalances found in borderline ovarian tumors seem to be similar to imbalances already known from the more extensively studied overt ovarian carcinomas, we speculate that the subset of borderline tumors with detectable imbalances or karyotypic aberrations may contain a smaller subset of tumors with a tendency to develop a more malignant phenotype. The group of borderline tumors with no imbalances would, in this line of thinking, have less or no propensity for clonal evolution and development to full-blown carcinomas.</p

    Novel Fusion of MYST/Esa1-Associated Factor 6 and PHF1 in Endometrial Stromal Sarcoma

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    Rearrangement of chromosome band 6p21 is recurrent in endometrial stromal sarcoma (ESS) and targets the PHF1 gene. So far, PHF1 was found to be the 3β€² partner in the JAZF1-PHF1 and EPC1-PHF1 chimeras but since the 6p21 rearrangements involve also other chromosomal translocation partners, other PHF1-fusions seem likely. Here, we show that PHF1 is recombined with a novel fusion partner, MEAF6 from 1p34, in an ESS carrying a t(1;6)(p34;p21) translocation as the sole karyotypic anomaly. 5β€²-RACE, RT-PCR, and sequencing showed the presence of an MEAF6-PHF1 chimera in the tumor with exon 5 of MEAF6 being fused in-frame to exon 2 of PHF1 so that the entire PHF1 coding region becomes the 3β€² terminal part of the MEAF6-PHF1 fusion. The predicted fusion protein is composed of 750 amino acids and contains the histone acetyltransferase subunit NuA4 domain of MEAF6 and the tudor, PHD zinc finger, and MTF2 domains of PHF1. Although the specific functions of the MEAF6 and PHF1 proteins and why they are targeted by a neoplasia-specific gene fusion are not directly apparent, it seems that rearrangement of genes involved in acetylation (EPC1, MEAF6) and methylation (PHF1), resulting in aberrant gene expression, is a common theme in ESS pathogenesis

    Adult enteric nervous system in health is maintained by a dynamic balance between neuronal apoptosis and neurogenesis

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    According to current dogma, there is little or no ongoing neurogenesis in the fully developed adult enteric nervous system. This lack of neurogenesis leaves unanswered the question of how enteric neuronal populations are maintained in adult guts, given previous reports of ongoing neuronal death. Here, we confirm that despite ongoing neuronal cell loss because of apoptosis in the myenteric ganglia of the adult small intestine, total myenteric neuronal numbers remain constant. This observed neuronal homeostasis is maintained by new neurons formed in vivo from dividing precursor cells that are located within myenteric ganglia and express both Nestin and p75NTR, but not the pan-glial marker Sox10. Mutation of the phosphatase and tensin homolog gene in this pool of adult precursors leads to an increase in enteric neuronal number, resulting in ganglioneuromatosis, modeling the corresponding disorder in humans. Taken together, our results show significant turnover and neurogenesis of adult enteric neurons and provide a paradigm for understanding the enteric nervous system in health and disease
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