400 research outputs found
Copulas, multivariate risk-neutral distributions and implied dependence functions
In this paper, we use copulas to define multivariate risk-neutral distributions. We can then derive general pricing formulas for multi-asset options and best possible bounds with given volatility smiles. Finally, we apply the copula framework to define ‘forward-looking ’ indicators of the dependence function between asset returns.
Multiple focal nodular hyperplasias induced by oxaliplatin-based chemotherapy
that affects normal liver with low prevalence. Recently, the extensive use of oxaliplatin to treat patients with colorectal cancer has been reported to be associated with the development of different liver injuries, as well as focal liver lesions. The present work describes two patients with multiple bilateral focal liver lesions misdiagnosed as colorectal liver metastases, and treated with liver resection. The first patient had up to 15 small bilateral focal liver lesions, with magnetic resonance imaging consistent with colorectal liver metastases (CLM), and fluorodeoxyglucose (FDG)-positron emission tomography (PET) negative. The second patient had up to 5 small focal liver lesions, with computed tomography consistent with CLM, and FDG-PET negative. They had parenchyma sparing liver surgery, with uneventful postoperative course. At the histology the diagnosis was multiple FNHs. The risks of oxaliplatinbased chemotherapy regimens in development of liver injuries, such as FNH, should not be further denied. The value of the modern multidisciplinary management of patients with colorectal cancer relies also on the precise estimation of the risk/benefit for each patien
Genetic and epigenetic changes in primary metastatic and nonmetastatic colorectal cancer
Colorectal cancer (CRC) develops as multistep process, which involves genetic and epigenetic alterations. K-Ras, p53 and B-Raf mutations and RASSF1A, E-Cadherin and p16INK4A promoter methylation were investigated in 202 CRCs with and without lymph node and/or liver metastasis, to assess whether gene abnormalities are related to a metastogenic phenotype. K-Ras, B-Raf and p53 mutations were detected in 27, 3 and 32% of the cases, with K-Ras mutations significantly associated with metastatic tumour (P=0.019). RASSF1A, E-Cadherin and p16INK4A methylation was documented in 20, 44 and 33% of the cases with p16INK4A significantly associated with metastatic tumours (P=0.001). Overall, out of 202 tumours, 34 (17%) did not show any molecular change, 125 (62%) had one or two and 43 (21%) three or more. Primary but yet metastatic CRCs were prevalent in the latter group (P=0.023) where the most frequent combination was one genetic (K-Ras in particular) and two epigenetic alterations. In conclusion, this analysis provided to detect some molecular differences between primary metastatic and nonmetastatic CRCs, with K-Ras and p16INK4A statistically altered in metastatic tumours; particular gene combinations, such as coincidental K-Ras mutation with two methylated genes are associated to a metastogenic phenotype
Social determinants of dental treatment needs in Brazilian adults.
The chronic cumulative nature of caries makes treatment needs a severe problem in adults. Despite the fact that oral diseases occur in social contexts, there are few studies using multilevel analyses focusing on treatment needs. Thus, considering the importance of context in explaining oral health related inequalities, this study aims to evaluate the social determinants of dental treatment needs in 35-44 year old Brazilian adults, assessing whether inequalities in needs are expressed at individual and contextual levels
Prediction of a neuropeptidome for the eyestalk ganglia of the lobster Homarus americanus using a tissue-specific de novo assembled transcriptome
In silico transcriptome mining is a powerful tool for crustacean peptidome prediction. Using homology-based BLAST searches and a simple bioinformatics workflow, large peptidomes have recently been predicted for a variety of crustaceans, including the lobster, Homarus americanus. Interestingly, no in silico studies have been conducted on the eyestalk ganglia (lamina ganglionaris, medulla externa, medulla interna and medulla terminalis) of the lobster, although the eyestalk is the location of a major neuroendocrine complex, i.e., the X-organ-sinus gland system. Here, an H. americanus eyestalk ganglia-specific transcriptome was produced using the de novo assembler Trinity. This transcriptome was generated from 130,973,220 Illumina reads and consists of 147,542 unique contigs. Eighty-nine neuropeptide-encoding transcripts were identified from this dataset, allowing for the deduction of 62 distinct pre/preprohormones. Two hundred sixty-two neuropeptides were predicted from this set of precursors; the peptides include members of the adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon α, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone (CHH), CHH precursor-related peptide, diuretic hormone 31, diuretic hormone 44, eclosion hormone, elevenin, FMRFamide-like peptide, glycoprotein hormone α2, glycoprotein hormone β5, GSEFLamide, intocin, leucokinin, molt-inhibiting hormone, myosuppressin, neuroparsin, neuropeptide F, orcokinin, orcomyotropin, pigment dispersing hormone, proctolin, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide, sulfakinin, tachykinin-related peptide and trissin families. The predicted peptides expand the H. americanus eyestalk ganglia neuropeptidome approximately 7-fold, and include 78 peptides new to the lobster. The transcriptome and predicted neuropeptidome described here provide new resources for investigating peptidergic signaling within/from the lobster eyestalk ganglia
Insulin-like growth factor receptor 1 (IGF1R) expression and survival in surgically resected non-small-cell lung cancer (NSCLC) patients
Background: The purpose of this study is to investigate the prognostic role of insulin-like growth factor receptor 1 (IGF1R) expression in surgically resected non-small-cell lung cancer (NSCLC). Patient characteristics and methods: This retrospective study was conducted in 369 stage I-II-IIIA, surgically resected, NSCLC patients. Patients exposed to anti-epidermal growth factor receptor (EGFR) agents were excluded. IGF1R expression was evaluated by immunohistochemistry in tissue microarray sections. Results: A positive IGF1R expression (score ≥ 100) was observed in 282 cases (76.4%) and was significantly associated with squamous cell histology (P = 0.04) and with grade III differentiation (P = 0.02). No difference in survival was observed between the positive and negative group when score 100 was used as cut-off for discriminating a positive versus a negative IGF1R result (52 versus 48 months, P = 0.99) or when median value of IGF1R expression was used (45 versus 55 months, P = 0.36). No difference in survival was observed between IGF1R-positive and -negative patients in a subgroup of stage I-II adenocarcinoma (n = 137) with known EGFR mutation and copy number status. Conclusions: IGF1R expression does not represent a prognostic factor in resected NSCLC patients. Patients with squamous cell carcinoma overexpress IGF1R more frequently than patients with nonsquamous histology, justifying the different sensitivity to anti-IGF1R agents observed in clinical trial
Morphophenotypic changes in human multistep hepatocarcinogenesis with translational implications
BACKGROUND & AIMS:
Human hepatocarcinogenesis in cirrhosis is thought to be multistep and characterized by a spectrum of nodular lesions, ranging from low to high grade dysplastic nodules (LGDN and HGDN) to early and progressed hepatocellular carcinoma (eHCC and pHCC). Aim of this study was to investigate the morpho-phenotypical changes of this sequence and their potential translational significance.
METHODS:
We scored the vascular profile, ductular reaction/stromal invasion and overexpression of 5 biomarkers (GPC3, HSP70, GS, CHC, and EZH2), in a series of 100 resected nodules (13 LGDN, 16 HGDN, 42 eHCC and 29 small pHCC).
RESULTS:
The score separated the 4 groups of nodules as individual entities (p<0.01). In the sequence, biomarkers overexpression progressively increased with parallel decrease of ductular reaction; the vascular remodeling started very early (LGDN) but did not further develop in a proportion of HCC. eHCC was the most heterogeneous entity, with marginal overlap with HGDN and pHCC. Liver environment (fibrosis, etiology) did not impact on the phenotype of the different nodules. A subclass of eHCC (16/42) without evidence of stromal invasion was identified, suggesting a "preinvasive stage" (p<0.05). For diagnosis, the application of 4 and 5 biomarkers (rather than the usual 3) improved the sensitivity of the assay for the detection of eHCC (76% and 93% vs. 52%); biomarkers in alternative combinations also increased the sensitivity of the assay (GS+CHC+EZH2: 76%; GS+CHC+EZH2+HSP70: 90%).
CONCLUSIONS:
This study supports the multistep nature of human hepatocarcinogenesis, suggests that eHCC is more heterogeneous than previously thought and provides information of potential translational significance into the clinical practice
Nested stromal-epithelial tumour of the liver : An unusual liver entity
Nested stromal-epithelial tumours (NSETs) of the liver have been reported to be extremely unusual primary hepatic neoplasms. To date, few cases have been described in the literature. NSETs have been defined as non-hepatocytic and non-biliary tumours of the liver consisting of nests of epithelial and spindled cells, myofibroblastic stroma and variable intralesional calcification and ossification. Here, we report a case of a young female who underwent liver resection for a large hepatic lesion that proved to be a calcifying NSET on pathological examination. Details about the clinical and histopathological features of the tumour are reported
Circadian signaling in Homarus americanus: Region-specific de novo assembled transcriptomes show that both the brain and eyestalk ganglia possess the molecular components of a putative clock system
Essentially all organisms exhibit recurring patterns of physiology/behavior that oscillate with a period of ~24-h and are synchronized to the solar day. Crustaceans are no exception, with robust circadian rhythms having been documented in many members of this arthropod subphylum. However, little is known about the molecular underpinnings of their circadian rhythmicity. Moreover, the location of the crustacean central clock has not been firmly established, although both the brain and eyestalk ganglia have been hypothesized as loci. The American lobster, Homarus americanus, is known to exhibit multiple circadian rhythms, and immunodetection data suggest that its central clock is located within the eyestalk ganglia rather than in the brain. Here, brain- and eyestalk ganglia-specific transcriptomes were generated and used to assess the presence/absence of transcripts encoding the commonly recognized protein components of arthropod circadian signaling systems in these two regions of the lobster central nervous system. Transcripts encoding putative homologs of the core clock proteins clock, cryptochrome 2, cycle, period and timeless were found in both the brain and eyestalk ganglia assemblies, as were transcripts encoding similar complements of putative clock-associated, clock input pathway and clock output pathway proteins. The presence and identity of transcripts encoding core clock proteins in both regions were confirmed using PCR. These findings suggest that both the brain and eyestalk ganglia possess all of the molecular components needed for the establishment of a circadian signaling system. Whether the brain and eyestalk clocks are independent of one another or represent a single timekeeping system remains to be determined. Interestingly, while most of the proteins deduced from the identified transcripts are shared by both the brain and eyestalk ganglia, assembly-specific isoforms were also identified, e.g., several period variants, suggesting the possibility of region-specific variation in clock function, especially if the brain and eyestalk clocks represent independent oscillators
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