2,166 research outputs found
Replication and Encapsidation of Papillomaviruses in \u3ci\u3eSaccharomyces cerevisiae\u3c/i\u3e
Improvements in methodologies to recapitulate and study particular biological functions of the
papillomavirus life cycle have led to great advances in our knowledge of these viruses. Described in
this chapter are techniques that allow low-copy and high-copy replication of full-length human
papillomavirus (HPV) genomes, as well as assembly of virus-like particles, in Saccharomyces
cerevisiae (yeast). This system has several distinct advantages that make it an attractive complement
to the well-established raft-culturing system. First, yeast are inexpensive, rapid, and simple to culture
in the lab. Second, they provide an ever-widening array of genetic tools to analyze HPV functions
—most recently notable, the yeast ORF-deletion library. Third, yeast provide a potentially high efficiency
means to produce large quantities of infectious virus in a short time frame. Fourth,
assembly of HPV virus in yeast allows encapsidation of mutant genomes, since previous studies have
shown that no viral ORF is required for replication of full-length HPV in yeast
Random projection to preserve patient privacy
With the availability of accessible and widely used cloud services, it is natural that large components of healthcare systems migrate to them; for example, patient databases can be stored and processed in the cloud. Such cloud services provide enhanced flexibility and additional gains, such as availability, ease of data share, and so on. This trend poses serious threats regarding the privacy of the patients and the trust that an individual must put into the healthcare system itself. Thus, there is a strong need of privacy preservation, achieved through a variety of different approaches. In this paper, we study the application of a random projection-based approach to patient data as a means to achieve two goals: (1) provably mask the identity of users under some adversarial-attack settings, (2) preserve enough information to allow for aggregate data analysis and application of machine-learning techniques. As far as we know, such approaches have not been applied and tested on medical data. We analyze the tradeoff between the loss of accuracy on the outcome of machine-learning algorithms and the resilience against an adversary. We show that random projections proved to be strong against known input/output attacks while offering high quality data, as long as the projected space is smaller than the original space, and as long as the amount of leaked data available to the adversary is limited
How the Cervical Microbiota Contributes to Cervical Cancer Risk in Sub-Saharan Africa
Despite ongoing efforts, sub-Saharan Africa faces a higher cervical cancer burden than anywhere else in the world. Besides HPV infection, definitive factors of cervical cancer are still unclear. Particular states of the cervicovaginal microbiota and viral infections are associated with increased cervical cancer risk. Notably, HIV infection, which is prevalent in sub-Saharan Africa, greatly increases risk of cervicovaginal dysbiosis and cervical cancer. To better understand and address cervical cancer in sub-Saharan Africa, a better knowledge of the regional cervicovaginal microbiome is required This review establishes current knowledge of HPV, HIV, cervicovaginal infections, and the cervicovaginal microbiota in sub-Saharan Africa. Because population statistics are not available for the region, estimates are derived from smaller cohort studies. Microbiota associated with cervical inflammation have been found to be especially prevalent in sub-Saharan Africa, and to associate with increased cervical cancer risk. In addition to high prevalence and diversity of HIV and HPV, intracellular bacterial infections such as Chlamydia, Gonorrhea, and Mycoplasma hominis are much more common than in regions with a low burden of cervical cancer. This suggests the prevalence of cervical cancer in sub-Saharan Africa may be partially attributed to increased cervical inflammation resulting from higher likelihood of cervical infection and/or microbial dysbiosis
Managing rare and undetectable events in risk assessment: the case of a satellite system launch project
Assessing the wide diversity of risk types in large and complex projects using the traditional hyperbolic iso-risks curves may seem a simplistic and reductive approach, and evaluating the risk factor through the multiplication of likelihood and severity parameters results in defining as dangerous those risks that are associated either with rare but devastating consequences or with probable but minor effects. In this work, the authors aimed at focusing on those risks that, despite their low occurrence probability, may significantly compromise a project result. To this extent, a different formula has been used to compute the risk factor, keeping into account risk detectability and evaluating the potential consequences in four different domains (cost, time, performance, reputation). This approach has been validated on the case of a large industrial project related to the launch of an innovative mobile telecommunications system, collecting the experts' opinions in a primary Italian firm in aerospace industry
Evolutionary variation of papillomavirus E2 protein and E2 binding sites
Background: In an effort to identify the evolutionary changes relevant to E2 function, within and between papillomavirus genera, we evaluated the E2 binding sites (E2BS)s inside the long-control-region (LCR), and throughout the genomes. We identified E2BSs in the six largest genera of papillomaviruses: Alpha, Beta, Gamma, Delta, Lambda, and Xi-papillomaviruses (128 genomes), by comparing the sequences with a model consensus we created from known functional E2BSs (HPV16, HPV18, BPV1). We analyzed the sequence conservation and nucleotide content of the 4-nucleotide spacer within E2BSs. We determined that there is a statistically significant difference in GC content of the four-nucleotide E2BS spacer, between Alpha and Delta-papillomaviruses, as compared to each of the other groups. Additionally, we performed multiple alignments of E2 protein sequences using members of each genus in order to identify evolutionary changes within the E2 protein.
Results: When a phylogenetic tree was generated from E2 amino acid sequences, it was discovered that the alpha-papillomavirus genera segregates into two distinct subgroups (α1 and α2). When these subgroups were individually analyzed, it was determined that the subgroup α1 consensus E2BS favored a spacer of AAAA, whereas subgroup α2 favored the opposite orientation of the same spacer; TTTT. This observation suggests that these conserved inverted linkers could have functional importance
Investigating the Physiological Mechanisms between Resistance Training and Pain Relief in the Cancer Population: A Literature Review
This literature review examines the mechanisms of how exercise, specifically in the form of resistance training, may lead to pain relief in the cancer population. Primary data from three different cancer populations: breast, prostate, and lung, will be examined. A number of experimental studies have been conducted to confirm the effectiveness of resistance training on pain relief as well as the biochemical pathways that relate to this process. In this review, we will examine 5 randomized controlled trials. For the purposes of this review, pain is defined as physical suffering or discomfort associated with illness. Pain is the body’s natural signal, bringing attention to damage that has been sustained by tissues. However, chronic pain is common in the cancer population, and often serves no good purpose but instead will negatively impact both physical and mental health. The three types of pain: nociceptive, neuropathic, and inflammatory pathways have been investigated, and the knowledge of pain mechanisms allows for the understanding of how it is associated with pain. The purpose of this exploratory literature review is to give insight on how to maximize pain-relieving effects of resistance training. Research has indicated that resistance training modulates pain pathways by upregulating the release of pain-relieving substances including beta-endorphins, anti-inflammatory cytokines, and endocannabinoids. Understanding of the benefits of resistance training may be useful in relieving cancer pain, and reproducing effects of pain-relieving strategies while minimizing the symptoms related to cancer and its treatment
Functional Implications in Apoptosis by Interferon Inducible Gene Product 1-8D, the Binding Protein to Adenovirus Preterminal Protein
Adenovirus (Ad) precursor to the terminal protein (pTP) plays an essential roles in the viral DNA
replication. Ad pTP serves as a primer for the synthesis of a new DNA strand during the initiation
step of replication. In addition, Ad pTP forms organized spherical replication foci on the nuclear
matrix (NM) and anchors the viral genome to the NM. Here we identified the interferon inducible
gene product 1-8D (Inid) as a pTP binding protein by using a two-hybrid screen of a HeLa cDNA
library. Of the clones obtained in this assay, nine were identical to the Inid, a 13-kDa polypeptide
that shares homology with genes 1-8U and Leu-13/9-27, most of which have little known functions.
The entire open reading frame (ORF) of Inid was cloned into the tetracycline inducible expression
vector in order to determine the biological functions related with adenoviral infection. When Inid
was introduced to the cells along with adenoviruses, fifty to sixty percent of Ad-infected cells
expressing Inid had rounded morphology, which was suggestive of apoptosis. Results from the
terminal deoxynucleotidyl transferase (TdT) and DNA fragmentation assays confirmed that Inid
induces apoptosis in Ad-infected or in uninfected cells. The Inid binding to pTP may target the cell
for apoptotic destruction as a host defense mechanism against the viral infection
Differential localization of HPV16 E6 splice products with E6-associated protein
High-risk Human Papillomavirus (HPV) is the etiological agent associated with the majority of anogenital cancers. The primary HPV oncogenes, E6 and E7, undergo a complex splicing program resulting in protein products whose purpose is not fully understood. Previous mouse studies have confirmed the existence of a translated product corresponding to the E6*I splice product. In terms of function, the translated E6*I protein has been shown to bind to E6 protein and to E6 associated protein (E6AP). E6*I has an inhibitory effect on E6-mediated p53 degradation in E6 expressing cells. In order to analyze the relationship between E6*I and full-length E6 in relation to localization, we created a series of green fluorescent protein (GFP) fusion products. The localization of these proteins with reference to E6AP in vivo remains unclear. Therefore, we investigated the cellular distribution of different forms of E6 with reference to E6AP. E6 and E6*I proteins, expressed from a wild type E6 gene cassette, were dispersed in the nucleus and the cytoplasm. Whereas, the E6 splice donor mutant (E6MT) was primarily localized to the nucleus. E6*I protein and E6AP were found to co-localize mainly to the cytoplasm, whereas the co-localization of full-length E6 protein and E6AP, if at all, was found mainly at the perinuclear region. These results suggest a functional relationship between the E6*I and full-length E6 protein which correlates with their localization and likely is important in regulation of the E6-E6AP complex
On board Processor and Processing Strategies for Next Generation Reconfigurable Satellite Payloads
Today, the increasing demand in higher data rates necessitates new methods as well as higher flexibility for satellite telecommunication payloads in order to address a variety of applications and customers. This paper presents one of these processing strategies that is applicable to today’s processing satellite payloads aiming to meet those demands. For this purpose, a two-tier filter bank is designed as part of a digital onboard processor, which first divides the spectrum at the output of the ADC into a number of sub-bands extracting all the stacked channels in the digital domain. Following the analysis section of the first tier of operations, the extracted channels go under a secondary channelisation process to obtain much finer granularity of 31.25 kHz or 50 kHz depending on the communication standard used for data transmission. The implementation of the channeliser was delivered on a bit-true simulation model and the input and the output of the channelisers were compared and evaluated both in the time and frequency domains
Altered Expression of Adenovirus 12 DNA-Binding Protein but Not DNA Polymerase during Abortive Infection of Hamster Cells
Replication of human adenovirus type 12 DNA is blocked in abortively infected baby hamster kidney cells. The activity and accumulation of adenovirus 12 DNA polymerase is equivalent in infected hamster and human cell extracts. However, the accumulation of adenovirus type 12 DNA-binding protein is approximately 120-fold lower in extracts from infected hamster cells when compared to infected permissive human cells. This difference in accumulation is not because of replication of viral DNA during productive infection, since this difference is observed in the presence of hydroxyurea. The DNA-binding protein from infected hamster cells retains the ability to bind denatured DNA-cellulose. An adenovirus 5 early region 1 transformed hamster cell line competent to complement the adenovirus 12 DNA replication defect also stimulates accumulation of the DNA-binding protein even when the cells are treated with hydroxyurea. Thus, the reduced expression of the viral DNA-binding protein may play a role in the mechanism of abortive infection of hamster cells by adenovirus 12
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