598 research outputs found
The Replicative Consequences of Papillomavirus E2 Protein Binding to the Origin Replication Factor ORC2.
The origin recognition complex (ORC) coordinates a series of events that lead to initiation of DNA strand duplication. As a nuclear double stranded DNA plasmid, the papillomavirus (PV) genome resembles a mini-chromosome in infected cells. To initiate its replication, the viral E2 protein binds to and recruits the E1 DNA helicase at the viral origin. PV genome replication program exhibits three stages: initial amplification from a single genome upon infection to a few copies per cell, a cell cycle linked maintenance phase, and a differentiation dependent late stage where the genome is amplified to thousands of copies. Involvement of ORC or other pre-replication complex (pre-RC) factors has not been described. We report that human PV (HPV) and bovine PV (BPV-1) E2 proteins bind to ORC2, however, ORC2 was not detected at the viral origin. Depletion of ORC2 enhanced PV replication in a transient replication model and in keratinocytes stably maintaining viral episomes, while there was no effect on copy number in a cell line with integrated HPV genomes. Consistent with this, occupancy of E1 and E2 at the viral origin increased following ORC2 silencing. These data imply that ORC2 is not necessary for activation of the PV origin by E1 and E2 but instead suppresses E2 replicative function. Furthermore, we observed that over-expression of HPV E2 decreased ORC2 occupation at two known mammalian origins of replication, suggesting that E2 restricts pre-ORC assembly that could otherwise compete for host replication complexes necessary for viral genome amplification. We infer that the ORC2 complex with E2 restricts viral replication in the maintenance phase of the viral replication program and that elevated levels of E2 that occur during the differentiation dependent amplification stage subvert ORC loading and hence DNA synthesis at cellular origins
A 10-kDa Structural Protein of Porcine Reproductive and Respiratory Syndrome Virus Encoded by ORF2b
AbstractThe major structural proteins of porcine reproductive and respiratory syndrome virus (PRRSV) are derived from ORFs 5, 6, and 7. Western blots of sucrose gradient-purified virions and PRRSV-infected MARC-145 cells, probed with immune pig serum, showed the presence of an additional 10-kDa protein. Nucleotide sequence analysis of North American PRRSV isolate SDSU-23983 revealed a small ORF within ORF2, named ORF2b, which, when translated, produced a 73-amino-acid nonglycosylated protein. Recombinant 2b protein expressed by a baculovirus clone, AcVR2, comigrated with the 10-kDa virus-associated protein. The loss of 10-kDa protein immunoreactivity after absorption of immune sera with lysates from AcVR2-infected insect cells demonstrated that the 2b and 10-kDa proteins are immunologically similar. Immunoblots were also used for the detection of anti-2b activity in serum samples from experimentally infected adult pigs. Antibodies against PRRSV were apparent by 14 days postinfection, followed by anti-2b activity and serum neutralizing activity. The putative ORF2b start codon is only 6 nucleotides downstream of the adenine of the ORF2a start codon. The expression of ORF2a and 2b as enhanced green fluorescent fusion proteins showed that both proteins were translated; however, the ORF2b was preferentially expressed. These results suggest that the 2b protein is virion associated and the principal product of ORF2
HIGHER PLASMA TRIMETHYLAMINE-N-OXIDE IS ASSOCIATED WITH GREATER ATHEROSCLEROTIC BURDEN QUANTIFIED BY THE SYNTAX SCORE
Capsomer Vaccines Protect Mice from Vaginal Challenge with Human Papillomavirus
Capsomers were produced in bacteria as glutathione-S-transferase (GST) fusion proteins with human papillomavirus type 16 L1 lacking the first nine and final 29 residues (GST-HPV16L1Δ) alone or linked with residues 13–47 of HPV18, HPV31 and HPV45 L2 in tandem (GST-HPV16L1Δ-L2x3). Subcutaneous immunization of mice with GST-HPV16L1Δ or GST-HPV16L1Δ-L2x3 in alum and monophosphoryl lipid A induced similarly high titers of HPV16 neutralizing antibodies. GST-HPV16L1Δ-L2x3 also elicited moderate L2-specific antibody titers. Intravaginal challenge studies showed that immunization of mice with GST-HPV16 L1Δ or GST-HPV16L1Δ-L2x3 capsomers, like Cervarix®, provided complete protection against HPV16. Conversely, vaccination with GST-HPV16 L1Δ capsomers failed to protect against HPV18 challenge, whereas mice immunized with either GST-HPV16L1Δ-L2x3 capsomers or Cervarix® were each completely protected. Thus, while the L2-specific response was moderate, it did not interfere with immunity to L1 in the context of GST-HPV16L1Δ-L2x3 and is sufficient to mediate L2-dependent protection against an experimental vaginal challenge with HPV18
Disparities of time trends and birth cohort effects on invasive breast cancer incidence in Shanghai and Hong Kong pre- and post-menopausal women
© 2017 The Author(s). Background: Breast cancer is the leading cause of cancer morbidity among Shanghai and Hong Kong women, which contributes to 20-25% of new female cancer incidents. This study aimed to describe the temporal trend of breast cancer and interpret the potential effects on the observed secular trends. Methods: Cancer incident data were obtained from the cancer registries. Age-standardized incidence rate was computed by the direct method using the World population of 2000. Average annual percentage change (AAPC) in incidence rate was estimated by the Joinpoint regression. Age, period and cohort effects were assessed by using a log-linear model with Poisson regression. Results: During 1976-2009, an increasing trend of breast cancer incidence was observed, with an AAPC of 1.73 [95% confidence interval (CI): 1.54-1.92)] for women in Hong Kong and 2.83 (95% CI, 2.26-3.40) in Shanghai. Greater upward trends were revealed in Shanghai women aged 50 years old or above (AAPC = 3.09; 95% CI, 1.48-4.73). Using age at 50 years old as cut-point, strong birth cohort effects were shown in both pre- and post-menopausal women, though a more remarkable effect was suggested in Shanghai post-menopausal women. No evidence for a period effect was indicated. Conclusions: Incidence rate of breast cancer has been more speedy in Shanghai post-menopausal women than that of the Hong Kong women over the past 30 years. Decreased birth rate and increasing environmental exposures (e.g., light-at-night) over successive generations may have constituted major impacts on the birth cohort effects, especially for the post-menopausal breast cancer; further analytic studies are warranted.Link_to_subscribed_fulltex
Paradoxical Association of Enhanced Cholesterol Efflux With Increased Incident Cardiovascular Risks
Objective—Diminished cholesterol efflux activity of apolipoprotein B (apoB)–depleted serum is associated with prevalent coronary artery disease, but its prognostic value for incident cardiovascular events is unclear. We investigated the relationship of cholesterol efflux activity with both prevalent coronary artery disease and incident development of major adverse cardiovascular events (death, myocardial infarction, or stroke). Approach and Results—Cholesterol efflux activity from free cholesterol–enriched macrophages was measured in 2 case–control cohorts: (1) an angiographic cohort (n=1150) comprising stable subjects undergoing elective diagnostic coronary angiography and (2) an outpatient cohort (n=577). Analysis of media from cholesterol efflux assays revealed that the high-density lipoprotein fraction (1.06
Simple non-invasive scoring systems and histological scores in predicting mortality in patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis
[Background and Aim] There is debate among the hepatology community regarding the simple non-invasive scoring systems and histological scores (even it was developed for histological classification) in predicting clinical outcomes in patients with non-alcoholic fatty liver disease (NAFLD). This study aimed to determine whether the presence of simple non-invasive scoring systems and histological scores could predict all-cause mortality, liver-related mortality, and liver disease decompensation (liver failure, cirrhosis, hepatocellular carcinoma, or decompensated liver disease).[Methods] The pooled hazard ratio of prognostic factors and incidence rate per 1000 person-years in patients with NAFLD was calculated and further adjusted by two different models of handling the duplicated data.[Results] A total of 19 longitudinal studies were included. Most simple non-invasive scoring systems (Fibrosis-4 Score, BARD, and aspartate aminotransferase-to-platelet ratio index ) and histological scores (NAFLD activity score, Brunt, and "steatosis, activity, and fibrosis" ) failed in predicting mortality, and only the NAFLD fibrosis score > 0.676 showed prognostic ability to all-cause mortality (four studies, 7564 patients, 118 352 person-years followed up, pooled hazard ratio 1.44, 95% confidence interval [CI] 1.05–1.96). The incidence rate per 1000 person-years of all-cause mortality, liver-related mortality, cardiovascular-related mortality, and liver disease decompensation resulted in a pooled incidence rate per 1000 person-years of 22.65 (14 studies, 95% CI 9.62–53.31), 3.19 (7 studies, 95% CI 1.14–8.93), 6.02 (6 studies, 95% CI 4.69–7.74), and 11.46 (4 studies, 95% CI 5.33–24.63), respectively.[Conclusion] Non-alcoholic fatty liver disease fibrosis score showed promising prognostic value to all-cause mortality. Most present simple non-invasive scoring systems and histological scores failed to predict clinical outcomes.Peer reviewe
A Case of Parathyroid Carcinoma in Renal Hyperparathyroidism
Introduction: Parathyroid carcinoma is a rare malignant endocrine tumor that is usually associated with primary hyperparathyroidism. The coexistence of parathyroid carcinoma and renal hyperparathyroidism is a rare phenomenon. Hence, we present a case of parathyroid carcinoma in a patient with tertiary hyperparathyroidism. Case Presentation: Our patient is a 31-year-old woman with a past medical history of end-stage renal failure (ESRF), on hemodialysis for the past 18 years. She was referred by her nephrologist to the endocrine surgery department for consideration of parathyroidectomy in view of long-standing tertiary hyperparathyroidism complicated by hypercalcemia. Bedside ultrasonography scan (US) of the thyroid revealed three parathyroid glands and a hypoechoic right lower pole thyroid nodule with central calcification. Fine-needle aspiration cytology was performed for the suspected thyroid nodule on the same day, which eventually yielded a follicular lesion of undetermined significance. A right hemithyroidectomy and total parathyroidectomy with deltoid implantation was performed. Intraoperative exploration revealed that the thyroid nodule noted at initial US was found to be the right superior parathyroid gland invading into the right thyroid itself. The right superior parathyroid gland was excised en bloc with the right hemithyroidectomy. Post-operatively, the patient was hypocalcemic but was discharged well on post-operative day 5. Histopathological diagnosis of the right hemithyroidectomy specimen containing the right superior parathyroid gland was consistent with that of parathyroid carcinoma. Conclusion: Parathyroid carcinoma is a rare entity that is difficult to diagnose. In patients with ESRF, the presence of concurrent tertiary hyperparathyroidism makes this even more challenging
Interest-driven creator theory: towards a theory of learning design for Asia in the twenty-first century
Asian education is known for its examination-driven orientation, with the downsides of distorting the processes of learning and teaching, diminishing students’ interest in learning, and failing to nurture twenty-first century competencies among students. As a group of Asian researchers, we have been developing Interest-Driven Creator (IDC) Theory, a design theory based on three anchored concepts, namely interest, creation, and habit. Each of these anchored concepts is represented by a loop composed of three components. In the interest loop, the three components are triggering, immersing, and extending. The components of the creation loop are imitating, combining, and staging. The habit loop consists of cuing environment, routine, and harmony. These three loops are interconnected in various ways, with their characteristics revealed by the design process. We hypothesize that technology-supported learning activities that are designed with reference to IDC Theory will enable students to develop interest in learning, be immersed in the creation process, and, by repeating this process in their daily routines, strengthen habits of creation. Furthermore, students will excel in learning performance, develop twenty-first century competencies, and become lifelong interest-driven creators. To sharpen our understanding and further the development of the theory, we need more discussion and collaborative efforts in the community. Hypotheses arising from this theory can be tested, revised, or refined by setting up and investigating IDC Theory-based experimental sites. By disseminating the framework, foundations, and practices to the various countries and regions of Asia, we hope that it will bring about compelling examples and hence a form of quality education for the twenty-first century, which is an alternative to the examination-driven education system. In this paper, we present an overall introduction to IDC Theory and its history, and discuss some of the steps for advancing it in the future
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