46 research outputs found

    Lepton masses in a supersymmetric 3-3-1 model

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    We consider the mass generation for both charginos and neutralinos in a 3-3-1 supersymmetric model. We show that R-parity breaking interactions leave the electron and one of the neutrinos massless at the tree level. However the same interactions induce masses for these particles at the 1-loop level. Unlike the similar situation in the MSSM the masses of the neutralinos are related to the masses of the charginos.Comment: RevTex, 11 pages incluing 2 .eps figures. Extended published versio

    Primary hyperparathyroidism: review and recommendations on evaluation, diagnosis, and management. A Canadian and international consensus

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    The purpose of this review is to assess the most recent evidence in the management of primary hyperparathyroidism (PHPT) and provide updated recommendations for its evaluation, diagnosis and treatment. A Medline search of "Hyperparathyroidism. Primary" was conducted and the literature with the highest levels of evidence were reviewed and used to formulate recommendations. PHPT is a common endocrine disorder usually discovered by routine biochemical screening. PHPT is defined as hypercalcemia with increased or inappropriately normal plasma parathyroid hormone (PTH). It is most commonly seen after the age of 50 years, with women predominating by three to fourfold. In countries with routine multichannel screening, PHPT is identified earlier and may be asymptomatic. Where biochemical testing is not routine, PHPT is more likely to present with skeletal complications, or nephrolithiasis. Parathyroidectomy (PTx) is indicated for those with symptomatic disease. For asymptomatic patients, recent guidelines have recommended criteria for surgery, however PTx can also be considered in those who do not meet criteria, and prefer surgery. Non-surgical therapies are available when surgery is not appropriate. This review presents the current state of the art in the diagnosis and management of PHPT and updates the Canadian Position paper on PHPT. An overview of the impact of PHPT on the skeleton and other target organs is presented with international consensus. Differences in the international presentation of this condition are also summarized

    Classical Simulation of Relativistic Quantum Mechanics in Periodic Optical Structures

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    Spatial and/or temporal propagation of light waves in periodic optical structures offers a rather unique possibility to realize in a purely classical setting the optical analogues of a wide variety of quantum phenomena rooted in relativistic wave equations. In this work a brief overview of a few optical analogues of relativistic quantum phenomena, based on either spatial light transport in engineered photonic lattices or on temporal pulse propagation in Bragg grating structures, is presented. Examples include spatial and temporal photonic analogues of the Zitterbewegung of a relativistic electron, Klein tunneling, vacuum decay and pair-production, the Dirac oscillator, the relativistic Kronig-Penney model, and optical realizations of non-Hermitian extensions of relativistic wave equations.Comment: review article (invited), 14 pages, 7 figures, 105 reference

    Epithelial PD-L2 Expression Marks Barrett's Esophagus and Esophageal Adenocarcinoma

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    Esophageal adenocarcinoma (EAC) is an increasingly common disease with a dismal 5-year survival rate of 10-15%. In the first systematic evaluation of the PD-1 pathway in EAC, we identify expression of PD-L2 in cancer cells in 51.7% of EACs. Epithelial PD-L1 was expressed on only 2% of cases, though PD-L1(+) immune cells were observed in 18% of EACs. We also evaluated expression in the precursor lesion of EAC, Barrett's Esophagus (BE), which emerges following gastric reflux-induced esophageal inflammation, and found PD-L2 expression in BE but not in non-BE esophagitis. As the progression from squamous esophagitis to BE is accompanied by a transition from a Th1 to Th2 immune response, we hypothesized that the Th2 cytokines IL4/IL13 could contribute to PD-L2 induction. We confirmed that these cytokines can augment PD-L2 expression in EAC cell lines. These results suggest that the inflammatory environment in BE and EAC may contribute to the expression of PD-L2. Furthermore, the potential for PD-1 receptor blockade to be effective in EACs with epithelial PD-L2 or immune cell PD-L1 expression should be evaluated in clinical trials

    Epithelial PD-L2 Expression Marks Barrett's Esophagus and Esophageal Adenocarcinoma

    No full text
    Esophageal adenocarcinoma (EAC) is an increasingly common disease with a dismal 5-year survival rate of 10-15%. In the first systematic evaluation of the PD-1 pathway in EAC, we identify expression of PD-L2 in cancer cells in 51.7% of EACs. Epithelial PD-L1 was expressed on only 2% of cases, though PD-L1(+) immune cells were observed in 18% of EACs. We also evaluated expression in the precursor lesion of EAC, Barrett's Esophagus (BE), which emerges following gastric reflux-induced esophageal inflammation, and found PD-L2 expression in BE but not in non-BE esophagitis. As the progression from squamous esophagitis to BE is accompanied by a transition from a Th1 to Th2 immune response, we hypothesized that the Th2 cytokines IL4/IL13 could contribute to PD-L2 induction. We confirmed that these cytokines can augment PD-L2 expression in EAC cell lines. These results suggest that the inflammatory environment in BE and EAC may contribute to the expression of PD-L2. Furthermore, the potential for PD-1 receptor blockade to be effective in EACs with epithelial PD-L2 or immune cell PD-L1 expression should be evaluated in clinical trials

    Densitometer-Specific Differences in the Correlation Between Body Mass Index and Lumbar Spine Trabecular Bone Score.

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    Trabecular bone score (TBS) is a gray-level texture measure derived from lumbar spine dual-energy X-ray absorptiometry (DXA) images that predicts fractures independent of bone mineral density (BMD). Increased abdominal soft tissue in individuals with elevated body mass index (BMI) absorbs more X-rays during image acquisition for BMD measurement and must be accommodated by the TBS algorithm. We aimed to determine if the relationship between BMI and TBS varied between 2 major manufacturers' densitometers, because different densitometers accommodate soft tissues differently. We identified 1919 women and 811 men, participants of the Canadian Multicentre Osteoporosis Study, aged ≄40 yr with lumbar spine DXA scans acquired on GE Lunar (4 centers) or Hologic (3 centers) densitometers at year 10 of follow-up. TBS was calculated for L1-L4 (TBS iNsightÂź software, version 2.1). A significant negative correlation between TBS and BMI was observed when TBS measurements were performed on Hologic densitometers in men (Pearson r = -0.36, p <0.0001) and in women (Pearson r = -0.33, p <0.0001); significant correlations were not seen when TBS was measured on GE Lunar densitometers (Pearson r = 0.00 in men, Pearson r = -0.02 in women). Age-adjusted linear regression models confirmed significant interactions between BMI and densitometer manufacturer for both men and women (p < 0.0001). In contrast, comparable positive correlations were observed between BMD and BMI on both Hologic and GE Lunar densitometers in men and women. In conclusion, BMI significantly affects TBS values in men and women when measured on Hologic but not GE Lunar densitometers. This finding has implications for clinical and research applications of TBS, especially when TBS is measured sequentially on DXA densitometers from different manufacturers or when results from different machines are pooled for analysis

    Three-gene immunohistochemical panel adds to clinical staging algorithms to predict prognosis for patients with esophageal adenocarcinoma

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    PURPOSE: Esophageal adenocarcinoma (EAC) is a highly aggressive disease with poor long-term survival. Despite growing knowledge of its biology, no molecular biomarkers are currently used in routine clinical practice to determine prognosis or aid clinical decision making. Hence, this study set out to identify and validate a small, clinically applicable immunohistochemistry (IHC) panel for prognostication in patients with EAC. PATIENTS AND METHODS: We recently identified eight molecular prognostic biomarkers using two different genomic platforms. IHC scores of these biomarkers from a UK multicenter cohort (N = 374) were used in univariate Cox regression analysis to determine the smallest biomarker panel with the greatest prognostic power with potential therapeutic relevance. This new panel was validated in two independent cohorts of patients with EAC who had undergone curative esophagectomy from the United States and Europe (N = 666). RESULTS: Three of the eight previously identified prognostic molecular biomarkers (epidermal growth factor receptor [EGFR], tripartite motif-containing 44 [TRIM44], and sirtuin 2 [SIRT2]) had the strongest correlation with long-term survival in patients with EAC. Applying these three biomarkers as an IHC panel to the validation cohort segregated patients into two different prognostic groups (P < .01). Adjusting for known survival covariates, including clinical staging criteria, the IHC panel remained an independent predictor, with incremental adverse overall survival (OS) for each positive biomarker (hazard ratio, 1.20; 95% CI, 1.03 to 1.40 per biomarker; P = .02). CONCLUSION: We identified and validated a clinically applicable IHC biomarker panel, consisting of EGFR, TRIM44, and SIRT2, that is independently associated with OS and provides additional prognostic information to current survival predictors such as stage
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