452 research outputs found
Paroxysmal fascicular tachycardia and ventricular tachycardia due to mechanical stimulation by a mitral valve prosthesis
Electrophysiologic studies were performed in a woman who had two varieties of paroxysmal wide QRS tachycardia after mitral valve replacement with a Starr-Edwards prosthesis. One tachycardia originated in the left anterior fascicle; QRS complexes were 100 ms wide and resembled right bundle branch block with left posterior fascicular block, and a His bundle potential preceded each QRS by an interval of 20 ms (compared with 50 ms during sinus rhythm). The other tachycardia originated in the left ventricle. Clinical and echocardiographic observations suggested that the tachycardias were caused by mechanical stimulation of the interventricular septum by the mitral prosthesis
Endometriosis-Associated Ovarian Cancer: A Review of Pathogenesis
Endometriosis is classically defined as the presence of endometrial glands and stroma outside of the endometrial lining and uterine musculature. With an estimated frequency of 5%–10% among women of reproductive age, endometriosis is a common gynecologic disorder. While in itself a benign lesion, endometriosis shares several characteristics with invasive cancer, has been shown to undergo malignant transformation, and has been associated with an increased risk of epithelial ovarian carcinoma (EOC). Numerous epidemiologic studies have shown an increased risk of EOC among women with endometriosis. This is particularly true for women with endometrioid and clear cell ovarian carcinoma. However, the carcinogenic pathways by which endometriosis associated ovarian carcinoma (EAOC) develops remain poorly understood. Current molecular studies have sought to link endometriosis with EAOC through pathways related to oxidative stress, inflammation and hyperestrogenism. In addition, numerous studies have sought to identify an intermediary lesion between endometriosis and EAOC that may allow for the identification of endometriosis at greatest risk for malignant transformation or for the prevention of malignant transformation of this common gynecologic disorder. The objective of the current article is to review the current data regarding the molecular events associated with EAOC development from endometriosis, with a primary focus on malignancies of the endometrioid and clear cell histologic sub-types
STAT1-deficient mice spontaneously develop estrogen receptor alpha-positive luminal mammary carcinomas
Abstract Introduction Although breast cancers expressing estrogen receptor-α (ERα) and progesterone receptors (PR) are the most common form of mammary malignancy in humans, it has been difficult to develop a suitable mouse model showing similar steroid hormone responsiveness. STAT transcription factors play critical roles in mammary gland tumorigenesis, but the precise role of STAT1 remains unclear. Herein, we show that a subset of human breast cancers display reduced STAT1 expression and that mice lacking STAT1 surprisingly develop ERα+/PR+ mammary tumors. Methods We used a combination of approaches, including histological examination, gene targeted mice, gene expression analysis, tumor transplantaion, and immunophenotyping, to pursue this study. Results Forty-five percent (37/83) of human ERα+ and 22% (17/78) of ERα- breast cancers display undetectable or low levels of STAT1 expression in neoplastic cells. In contrast, STAT1 expression is elevated in epithelial cells of normal breast tissues adjacent to the malignant lesions, suggesting that STAT1 is selectively downregulated in the tumor cells during tumor progression. Interestingly, the expression levels of STAT1 in the tumor-infiltrating stromal cells remain elevated, indicating that single-cell resolution analysis of STAT1 level in primary breast cancer biopsies is necessary for accurate assessment. Female mice lacking functional STAT1 spontaneously develop mammary adenocarcinomas that comprise > 90% ERα+/PR+ tumor cells, and depend on estrogen for tumor engraftment and progression. Phenotypic marker analyses demonstrate that STAT1-/- mammary tumors arise from luminal epithelial cells, but not myoepithelial cells. In addition, the molecular signature of the STAT1-/- mammary tumors overlaps closely to that of human luminal breast cancers. Finally, introduction of wildtype STAT1, but not a STAT1 mutant lacking the critical Tyr701 residue, into STAT1-/- mammary tumor cells results in apoptosis, demonstrating that the tumor suppressor function of STAT1 is cell-autonomous and requires its transcriptional activity. Conclusions Our findings demonstrate that STAT1 suppresses mammary tumor formation and its expression is frequently lost during breast cancer progression. Spontaneous mammary tumors that develop in STAT1-/- mice closely recapitulate the progression, ovarian hormone responsiveness, and molecular characteristics of human luminal breast cancer, the most common subtype of human breast neoplasms, and thus represent a valuable platform for testing novel treatments and detection modalities
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Puerperal mastitis: a reproductive event of importance affecting anti-mucin antibody levels and ovarian cancer risk
Purpose: Test the hypothesis that puerperal mastitis may alter immunity related to the mucin (MUC) family of glycoproteins and lower risk of ovarian cancer. Methods: In two case–control studies conducted in New England between 1998 and 2008, we examined the association between self-reported mastitis and ovarian cancer in 1,483 women with epithelial ovarian cancer and 1,578 controls. IgG1 antibodies against (MUC1) CA15.3 and (MUC16) CA125 were measured using electrochemiluminescence assays in a subset of controls (n = 200). Preoperative CA125 was recorded in 649 cases. The association between ovarian cancer and mastitis was assessed using unconditional logistic regression to calculate adjusted odds ratios, OR, and 95 % confidence intervals (CI). Associations between mastitis and anti-CA15.3 and anti-CA125 antibodies and preoperative CA125 levels were evaluated using adjusted linear regression models. Results: Prior mastitis was associated with a significantly lower risk of ovarian cancer: OR (and 95 % CI) of 0.67 (0.48, 0.94) adjusted for parity, breastfeeding, and other potential confounders. The association was strongest with 2 or more episodes of mastitis, and risk declined progressively with increasing number of children and episodes of mastitis. Among controls, prior mastitis was associated with significantly higher anti-CA15.3 and anti-CA125 antibody levels and, among cases, with significantly lower preoperative CA125 levels. Conclusion: Puerperal mastitis may produce long-lasting anti-mucin antibodies that may lower the risk of ovarian cancer, plausibly through enhanced immune surveillance. Studying immune reactions related to MUC1 and MUC16 in the 10–20 % of breastfeeding women who develop mastitis may suggest ways to duplicate its effects through vaccines based on both antigens
EnD-Seq and AppEnD: sequencing 3′ ends to identify nontemplated tails and degradation intermediates
Existing methods for detecting RNA intermediates resulting from exonuclease degradation are low-throughput and laborious. In addition, mapping the 3′ ends of RNA molecules to the genome after high-throughput sequencing is challenging, particularly if the 3′ ends contain post-transcriptional modifications. To address these problems, we developed EnD-Seq, a high-throughput sequencing protocol that preserves the 3′ end of RNA molecules, and AppEnD, a computational method for analyzing high-throughput sequencing data. Together these allow determination of the 3′ ends of RNA molecules, including nontemplated additions. Applying EnD-Seq and AppEnD to histone mRNAs revealed that a significant fraction of cytoplasmic histone mRNAs end in one or two uridines, which have replaced the 1–2 nt at the 3′ end of mature histone mRNA maintaining the length of the histone transcripts. Histone mRNAs in fly embryos and ovaries show the same pattern, but with different tail nucleotide compositions. We increase the sensitivity of EnD-Seq by using cDNA priming to specifically enrich low-abundance tails of known sequence composition allowing identification of degradation intermediates. In addition, we show the broad applicability of our computational approach by using AppEnD to gain insight into 3′ additions from diverse types of sequencing data, including data from small capped RNA sequencing and some alternative polyadenylation protocols
Bostonia: The Boston University Alumni Magazine. Volume 12
Founded in 1900, Bostonia magazine is Boston University’s main alumni publication
The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI
The first 42 elements of the Allen Telescope Array (ATA-42) are beginning to
deliver data at the Hat Creek Radio Observatory in Northern California.
Scientists and engineers are actively exploiting all of the flexibility
designed into this innovative instrument for simultaneously conducting surveys
of the astrophysical sky and conducting searches for distant technological
civilizations. This paper summarizes the design elements of the ATA, the cost
savings made possible by the use of COTS components, and the cost/performance
trades that eventually enabled this first snapshot radio camera. The
fundamental scientific program of this new telescope is varied and exciting;
some of the first astronomical results will be discussed.Comment: Special Issue of Proceedings of the IEEE: "Advances in Radio
Telescopes", Baars,J. Thompson,R., D'Addario, L., eds, 2009, in pres
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Autoantibody profiling to identify biomarkers of key pathogenic pathways in mucinous ovarian cancer
Mucinous epithelial ovarian cancers are clinically and morphologically distinct from the other histopathologic subtypes of ovarian cancer. Unlike other ovarian subtypes, epidemiologic studies have indicated that tobacco exposure is a significant risk factor for developing mucinous ovarian cancer. Detection of autoantibody reactivity is useful in biomarker discovery and for explaining the role of important pathophysiologic pathways in disease. In order to study if there are specific antibody biomarkers in the plasma samples of mucinous ovarian cancer patients, we have initiated a screen by employing a “reverse capture antibody microarray” platform that uses native host antigens derived from mucinous ovarian tissues as “baits” for the capture of differentially labeled patient and control autoantibodies. 35 autoantibodies that were significantly elevated in the cancer plasma samples compared with healthy controls, and six autoantibodies that segregated smoking and nonsmoking patients were identified. Functional annotation of the antibody targets has identified nine target antigens involved in integrin and Wnt signaling pathways. Immunohistochemistry of archived ovarian specimens showed significant overexpression of eight of the nine target antigens in mucinous ovarian tumor tissues, suggesting that plasma autoantibodies from mucinous ovarian cancer patients might have heightened reactivities with epitopes presented by these overexpressed antigens. Autoantibody profiling may have an unexpected utility in uncovering key signaling pathways that are dysregulated in the system of interest
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