1,988 research outputs found

    Mouse Mammary Tumor Virus Molecular Biology and Oncogenesis

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    Mouse mammary tumor virus (MMTV), which was discovered as a milk-transmitted, infectious cancer-inducing agent in the 1930s, has been used since that time as an animal model for the study of human breast cancer. Like other complex retroviruses, MMTV encodes a number of accessory proteins that both facilitate infection and affect host immune response. In vivo, the virus predominantly infects lymphocytes and mammary epithelial cells. High level infection of mammary epithelial cells ensures efficient passage of virus to the next generation. It also results in mammary tumor induction, since the MMTV provirus integrates into the mammary epithelial cell genome during viral replication and activates cellular oncogene expression. Thus, mammary tumor induction is a by-product of the infection cycle. A number of important oncogenes have been discovered by carrying out MMTV integration site analysis, some of which may play a role in human breast cancer

    Retroviruses 2004: Review of the 2004 Cold Spring Harbor Retroviruses conference

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    For the past several decades, retrovirologists from around the world have gathered in late May at the Cold Spring Harbor Laboratories in New York to present their studies in formal talks and posters, and to discuss their ongoing research informally at the bar or on the beach. As organizers of the 2004 Cold Spring Harbor Retroviruses Conference, we have been asked by the editors of Retrovirology to prepare a review of the meeting for publication on-line. Our goal in this review is not to provide a detailed description of data presented at the meeting but rather to highlight some of the significant developments reported this year. The review is structured in a manner that parallels the organization of the meeting; beginning with the entry phase of the replication cycle, proceeding with post-entry events, assembly and release, integration, reverse transcription, pathogenesis/host factors, RNA-related events (transcription, processing, export, and packaging) and finishing with antivirals. While the most striking developments this year involved post-entry events and assembly/release, significant progress was made towards elucidating a number of aspects of the retroviral replication cycle

    Phages & antibiotic resistance: are the most abundant entities on earth ready for a comeback?

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    Bacteriophages, which lost out to antibiotic therapy in the past, may be poised to make a comeback. Once discarded because of their narrow activity spectrum, it can now be viewed as a major advantage that these intracellular, self-replicating entities can exert their killing effect with minimal damage to the commensal microbiome. In eastern Europe, phages continue to be used both prophylactically and therapeutically to treat infections. More recently, much needed regulated clinical trials are underway with a view to restoring phage therapy as a tool for mainstream medicine, although current regulations may impede their full potential. One hundred years after their discovery, and amid an antibiotic resistance crisis, we must ask, what can be done to harness their full antibacterial potential

    Sexual health education for behavior change: How much is enough?

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    Purpose: Successful implementation of sexual health curricula in school settings is often compromised by competing academic priorities. This study explores the association between exposure to sexual health lessons (time-on-task in hours and lesson content topics) and delayed sexual initiation of middle school students at long term follow-up. Methods: Post hoc data analysis was conducted from a RCT (n=15 middle schools) in the south-central U.S. in which grade 7 students demonstrated delayed sexual initiation (adjusted odds ratio [AOR]: 1.54, 95% CI: 1.20 to 1.99) by grade 9 follow-up after using It’s Your Game (IYG), a 24 lesson sexual health curriculum. Logistic regression was conducted on a sub-sample of 314 grade 7 and 8 students who received IYG and who were sexually inexperienced at baseline, adjusting for covariates of age, gender, and race/ethnicity to address the impact of lesson exposure variables (time-on-task in hours and type of sexual health content) on initiation of any sex by grade 9. Results: The greatest impact of exposure on delayed sexual initiation was a duration of 13 or more lesson hours (OR = 8.40; p\u3c0.05) and exposure to lesson content on HIV/STI and pregnancy consequences (OR = 4.93; p\u3c0.05). Conclusions: Results support previous exposure studies and provide guidance on how effective sexual health curricula can meet the challenges of delivery in a reduced and competitive academic environment

    Enhancing the stress responses of probiotics for a lifestyle from gut to product and back again

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    Before a probiotic bacterium can even begin to fulfill its biological role, it must survive a battery of environmental stresses imposed during food processing and passage through the gastrointestinal tract (GIT). Food processing stresses include extremes in temperature, as well as osmotic, oxidative and food matrix stresses. Passage through the GIT is a hazardous journey for any bacteria with deleterious lows in pH encountered in the stomach to the detergent-like properties of bile in the duodenum. However, bacteria are equipped with an array of defense mechanisms to counteract intracellular damage or to enhance the robustness of the cell to withstand lethal external environments. Understanding these mechanisms in probiotic bacteria and indeed other bacterial groups has resulted in the development of a molecular toolbox to augment the technological and gastrointestinal performance of probiotics. This has been greatly aided by studies which examine the global cellular responses to stress highlighting distinct regulatory networks and which also identify novel mechanisms used by cells to cope with hazardous environments. This review highlights the latest studies which have exploited the bacterial stress response with a view to producing next-generation probiotic cultures and highlights the significance of studies which view the global bacterial stress response from an integrative systems biology perspective

    Reducing Sexual Risk among Racial/ethnic-minority Ninth Grade Students: Using Intervention Mapping to Modify an Evidenced-based Curriculum

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    Background: Racial/ethnic-minority 9th graders are at increased risk for teen pregnancy, HIV, and STIs compared to their White peers. Yet, few effective sexual health education programs exist for this population. Purpose: To apply IM Adapt—a systematic theory- and evidence-based approach to program adaptation—to modify an effective middle school sexual health education curriculum, It’s Your Game…Keep It Real! (IYG), for racial/ethnic-minority 9th graders. Methods: Following the six steps of IM Adapt, we conducted a needs assessment to describe the health problems and risk behaviors of the new population; reviewed existing evidence-based programs; assessed the fit of IYG for the new population regarding behavioral outcomes, determinants, change methods, delivery, and implementation; modified materials and activities; planned for implementation and evaluation. Results: Needs assessment findings indicated that IYG targeted relevant health and risk behaviors for racial/ethnic-minority 9th graders but required additional focus on contraceptive use, dating violence prevention, active consent, and access to healthcare services. Behavioral outcomes and matrices of change objectives for IYG were modified accordingly. Theoretical methods and practical applications were identified to address these behavioral outcomes, and new activities developed. Youth provided input on activity modifications. School personnel guided modifications to IYG’s scope and sequence, and delivery. The adapted program, Your Game, Your Life, comprised fifteen 30-minute lessons targeting determinants of sexual behavior and healthy dating relationships. Pilot-test data from 9th graders in two urban high schools indicate promising results. Conclusion: IM Adapt provides a systematic theory- and evidence-based approach for adapting existing evidence-based sexual health education curricula for a new population whilst retaining essential elements that made the original program effective. Youth and school personnel input ensured that the adapted program was age-appropriate, culturally sensitive, and responsive to the needs of the new population. IM Adapt contributes to the limited literature on systematic approaches to program adaptation

    Assessing the Need and Receptivity for an Integrated Healthy Sexual and Dating Relationships Intervention for Community College Students

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    Background: In emerging adulthood, youth often become involved in more serious romantic relationships. However, many lack the skills to avoid an unplanned pregnancy or sexually transmitted infection (STI), and to ensure a healthy dating relationship. Community college students serve nearly half of all undergraduate students in the United States; yet, community colleges typically lack resources for sexual health promotion. Purpose: To assess the need and receptivity for a web-based integrated healthy sexual and dating relationships intervention among community college students. Methods: In summer 2016, we partnered with three community colleges in South Central Texas to conduct an online survey of students’ sexual behaviors and dating relationships, and usability testing of activities from an integrated, web-based healthy sexual and dating relationship intervention. Results: Online survey participants (n=271) were 70% female, 38% Hispanic, 24% White, 17% Black, and 16% Asian; 20% self-identified as sexual minority; mean age was 20.8 years (SD = 2.05). Participants reported high rates of sexual risk behavior including sex without a condom or an effective birth control method, low use of long-acting reversible contraception, frequent use of emergency contraception, and low use of dual protection to prevent pregnancy and sexually transmitted infections. Two-thirds reported experiencing any type of dating violence perpetration or victimization in the past year. Usability testing participants (n=14) were 86% female, 42% Hispanic, 50% Asian/Pacific Islander, 14% Black, and 7% White; 71% were sexually experienced; mean age was 20.7 years (SD = 1.64). The web-based activities were highly rated in terms of usability parameters, and positively impacted short-term psychosocial outcomes related to condom use, accessing contraceptive health services, and constructive interpersonal conflict resolution. Conclusion: Findings underscore the high need and receptivity for an integrated healthy sexual and dating relationship web-based intervention among community college students, an understudied subgroup of youth in emerging adulthood

    Usability and Psychosocial Impact of Decision Support to Increase Sexual Health Education in American Indian and Alaska Native Communities

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    Despite sexual and reproductive health disparities, few evidence-based sexual health education programs exist for American Indian/Alaska Native (AI/AN) youth, with even fewer tools available to assist AI/AN communities in adopting, implementing, and maintaining such programs. iCHAMPSS (Choosing And Maintaining effective Programs for Sex education in Schools) is a theory- and web-based decision-support-system designed to address dissemination barriers and increase the reach and fidelity of evidence-based programs (EBPs), specifically sexual health education programs. To investigate the potential of iCHAMPSS in AI/AN communities, we pilot-tested iCHAMPSS with adult stakeholders (N = 36) from agencies across the country that serve AI/AN communities. Stakeholders were recruited to review selected iCHAMPSS tools over two weeks in spring 2016. Pre- and post-surveys were administered to assess usability constructs, short-term psychosocial outcomes, and perceived feasibility. Data were analyzed using descriptive and non-parametric statistics. iCHAMPSS was perceived as acceptable, easy to use, credible, appealing, more helpful than current resources, and impactful of EBP adoption, implementation, and maintenance. Conversely, using iCHAMPSS significantly increased participants’ perceived barriers to adopting an EBP (p = 0.01). Overall, AI/AN stakeholders responded positively to iCHAMPSS, indicating the potential for adaptation to support the dissemination and implementation of evidence-based sexual health education in AI/AN communities
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