Determinant of HIV-1 mutational escape from cytotoxic T lymphocytes.

CD8+ class I-restricted cytotoxic T lymphocytes (CTLs) usually incompletely suppress HIV-1 in vivo, and while analogous partial suppression induces antiretroviral drug-resistance mutations, epitope escape mutations are inconsistently observed. However, escape mutation depends on the net balance of selective pressure and mutational fitness costs, which are poorly understood and difficult to study in vivo. Here we used a controlled in vitro system to evaluate the ability of HIV-1 to escape from CTL clones, finding that virus replicating under selective pressure rapidly can develop phenotypic resistance associated with genotypic changes. Escape varied between clones recognizing the same Gag epitope or different Gag and RT epitopes, indicating the influence of the T cell receptor on pressure and fitness costs. Gag and RT escape mutations were monoclonal intra-epitope substitutions, indicating limitation by fitness constraints in structural proteins. In contrast, escape from Nef-specific CTL was more rapid and consistent, marked by a polyclonal mixture of epitope point mutations and upstream frameshifts. We conclude that incomplete viral suppression by CTL can result in rapid emergence of immune escape, but the likelihood is strongly determined by factors influencing the fitness costs of the particular epitope targeted and the ability of responding CTL to recognize specific epitope variants

Does Training Reduce Computer Anxiety?

This study uses a modified version of the Computer Anxiety Rating Scale (CARS) (Heinnsen, Glass, & Knight, 1987) to longitudinally analyze levels of student anxiety over time. We predict that computer anxiety will behave as a transitory state (Spielberger, 1970) that will respond favorably to interventions. Specifically, we predict that levels of computer anxiety will decrease after students in an introductory computer applications course complete assignments and receive training using personal productivity software tools. Further, we also plan to analyze gender differences in levels of computer anxiety. We propose that women will experience higher levels of computer anxiety than men both before and after training. We have already collected data and plan to statistically test our hypotheses and draw conclusions based on the results obtained

Mapping of ESE-1 subdomains required to initiate mammary epithelial cell transformation via a cytoplasmic mechanism

<p>Abstract</p> <p>Background</p> <p>The ETS family transcription factor ESE-1 is often overexpressed in human breast cancer. ESE-1 initiates transformation of MCF-12A cells via a non-transcriptional, cytoplasmic process that is mediated by a unique 40-amino acid serine and aspartic acid rich (SAR) subdomain, whereas, ESE-1's nuclear transcriptional property is required to maintain the transformed phenotype of MCF7, ZR-75-1 and T47D breast cancer cells.</p> <p>Results</p> <p>To map the minimal functional nuclear localization (NLS) and nuclear export (NES) signals, we fused in-frame putative NLS and NES motifs between GFP and the SAR domain. Using these GFP constructs as reporters of subcellular localization, we mapped a single NLS to six basic amino acids (²⁴²HGKRRR²⁴⁷) in the AT-hook and two CRM1-dependent NES motifs, one to the pointed domain (NES1: ¹⁰²LCNCALEELRL¹¹²) and another to the DNA binding domain (DBD), (NES2: ²⁷⁵LWEFIRDILI²⁸⁴). Moreover, analysis of a putative NLS located in the DBD (³¹⁶GQKKKNSN³²³) by a similar GFP-SAR reporter or by internal deletion of the DBD, revealed this sequence to lack NLS activity. To assess the role of NES2 in regulating ESE-1 subcellular localization and subsequent transformation potency, we site-specifically mutagenized NES2, within full-length GFP-ESE-1 and GFP-NES2-SAR reporter constructs. These studies show that site-specific mutation of NES2 completely abrogates ESE-1 transforming activity. Furthermore, we show that exclusive cytoplasmic targeting of the SAR domain is sufficient to initiate transformation, and we report that an intact SAR domain is required, since block mutagenesis reveals that an intact SAR domain is necessary to maintain its full transforming potency. Finally, using a monoclonal antibody targeting the SAR domain, we demonstrate that the SAR domain contains a region accessible for protein - protein interactions.</p> <p>Conclusions</p> <p>These data highlight that ESE-1 contains NLS and NES signals that play a critical role in regulating its subcellular localization and function, and that an intact SAR domain mediates MEC transformation exclusively in the cytoplasm, via a novel nontranscriptional mechanism, whereby the SAR motif is accessible for ligand and/or protein interactions. These findings are significant, since they provide novel molecular insights into the functions of ETS transcription factors in mammary cell transformation.</p

The impact of minority physician representation on minority patient health

Background: Before the COVID-19 pandemic, the medical profession underwent a physician burnout crisis. Post pandemic, physician burnout transformed into an epidemic that has contributed to the inability of physician supply to meet patient demand in the USA. Recent studies by the American Medical Association predict by 2034, a widespread physician shortage across both primary care and non-primary care specialties (AAMC, 2021). As a result, medical institutions have implemented programs to address this shortage. While this shortage is concerning and needs to be addressed, it isn’t the only shortage at hand. Minorities are deeply underrepresented in the medical field with respect to their proportions in the overall USA population. The ongoing physician shortage further exacerbates the disproportionate number of minority physicians. Furthermore, minority underrepresentation isn’t confined to the profession but is also observed among students in medical schools across the United States. Simultaneously, these same underrepresented minority groups disproportionately experience mortality and disability from disease at higher rates compared to their White counterparts (Smedley, 2001). This study analyzes the inverse relationship between the amount minority physicians present in a community and the prevalence of disease among these same minority populations. It also seeks to understand how representation impacts minority health outcomes. Aim: Involving minority communities in the development and implementation of healthcare policies and programs can lead to better healthcare outcomes for those communities. Methods: A systematic literature review was conducted using PubMed, Scopus, and EBSCOhost databases using keywords [(“MINORITY PHYSICIAN” OR “UNDERREPRESENTED MINORITY PHYSICIANS”)] AND [(“MINORITY PATIENTS” OR “MINORITY PATIENT HEALTH OUTCOMES”) AND (“COMMUNITY-BASED PARTICIPATORY RESEARCH”)] Results: The excess burden of illness in minority populations can be contributed to numerous complex factors, including but not limited to socioeconomic inequality, environmental and occupational exposures, discrimination, health risk factors, and less access to health insurance and healthcare. Practical, actionable strategies to address these disparities should include the engagement of families in leadership roles, provision of comprehensive healthcare, cross-sectoral institutional and community collaborations, and the use of community-based participatory research (CBPR) methods. CBPR has demonstrated promise in enhancing the effectiveness of interventions. However, the challenge remains to understand how and what type of partnerships and participation most effectively enhance the integration of science and practice to eliminate disparities. Discussion: Researchers, community leaders, and healthcare professionals are integral in delivering quality healthcare to minority communities. Researchers must be culturally competent enough to be able to go out into these communities and collect accurate data about these communities. Researchers must find effective strategies and methodologies to gain the trust of the minority community that their research is directly impacting. This can effectively be done by working with local community leaders and community organizations. Local community leaders have the responsibility of voicing the issues and barriers that the community has in accessing quality healthcare. Healthcare professionals have a responsibility to take the research data and work with community leaders to find effective ways to address disparities. In some cases, they may even have to seek funding through government agencies to ensure long-term solutions

Using Latent Profile Regression to Explore the Relationship between Religiosity and Work-related Ethical Judgments

Utilizing social structural symbolic interactionist theorizing about self-identity as presented by Weaver and Agle (2002) we obtained data related to five key measures of religiosity believed to be critical for understanding religiosity’s influence on ethical judgments. Using our five key religiosity measures we then fit a latent profile regression model to explore whether and how these constructs related to one another and to work-related ethical judgments. Results revealed that both our analytic and theoretical frameworks (latent profile regression and symbolic interactionism) were helpful in identifying religious profiles which are helpful for understanding the relationship between religiosity and work-related ethical judgments. More specifically, results indicated that extrinsic religious motivation orientation (RMO) may represent a ‘dark side’ to religiosity given higher levels of extrinsic RMO were found in a subgroup who judged unethical situations more favorably than those with lower levels of extrinsic RMO

The Nature of the Density Clump in the Fornax Dwarf Spheroidal Galaxy

We have imaged the recently discovered stellar overdensity located approximately one core radius from the center of the Fornax dwarf spheroidal galaxy using the Magellan Clay 6.5m telescope with the Magellan Instant Camera (MagIC). Superb seeing conditions allowed us to probe the stellar populations of this overdensity and of a control field within Fornax to a limiting magnitude of R=26. The color-magnitude diagram of the overdensity field is virtually identical to that of the control field with the exception of the presence of a population arising from a very short (less than 300 Myr in duration) burst of star formation 1.4 Gyr ago. Coleman et al. have argued that this overdensity might be related to a shell structure in Fornax that was created when Fornax captured a smaller galaxy. Our results are consistent with this model, but we argue that the metallicity of this young component favors a scenario in which the gas was part of Fornax itself.Comment: 24 pages including 8 figures and 3 tables. Accepted by Astronomical Journa

Single dose of Glycoprotein K (gK)-deleted HSV-1 live-attenuated virus protects mice against lethal vaginal challenge with HSV-1 and HSV-2 and induces lasting T cell memory immune responses

Background: Herpes simplex virus type-1(HSV-1) and HSV-2 are important human pathogens that cause significant ocular and urogenital complications, respectively. We have previously shown that HSV-1 virions lacking glycoprotein K (gK) are unable to enter into neurons via synaptic axonal membranes and be transported in either retrograde or anterograde manner. Here, we tested the ability of HSV-1 (F) gK-null to protect against lethal challenge with either highly virulent ocular HSV-1 (McKrae strain), or genital HSV-2 (G strain). The gK-null virus vaccine efficiently protected mice against lethal vaginal infection with either HSV-1(McKrae) or HSV-2 (G). Results: Female mice were immunized via a single intramuscular injection with 10§ssup§6§ esup§ PFU of the gK-null virus. Immunized mice were treated with Depo-Provera fourteen days after vaccination and were challenged via the vaginal route one week later. Ninety percent of mice vaccinated with the gK-null virus survived HSV-1 (McKrae) challenge, while 70% of these mice survived after HSV-2 (G) challenge. Moreover, all vaccinated mice exhibited substantially reduced disease symptoms irrespective of HSV-1 or HSV-2 challenge as compared to the mock vaccinated challenge group. T-cell memory immune responses to specific glycoprotein B (gB) and glycoprotein D (gD) peptide epitopes were detectable at 7 months post vaccination. Conclusions: These results suggest that the highly attenuated, non-neurotropic gK-null virus may be used as an effective vaccine to protect against both virulent HSV-1 and HSV-2 genital infections and induce lasting immune responses. © 2013 Iyer et al.; licensee BioMed Central Ltd

Wind field and sex constrain the flight speeds of central-place foraging albatrosses

By extracting energy from the highly dynamic wind and wave fields that typify pelagic habitats, albatrosses are able to proceed almost exclusively by gliding flight. Although energetic costs of gliding are low, enabling breeding albatrosses to forage hundreds to thousands of kilometers from their colonies, these and time costs vary with relative wind direction. This causes albatrosses in some areas to route provisioning trips to avoid headwind flight, potentially limiting habitat accessibility during the breeding season. In addition, because female albatrosses have lower wing loadings than males, it has been argued that they are better adapted to flight in light winds, leading to sexual segregation of foraging areas. We used satellite telemetry and immersion logger data to quantify the effects of relative wind speed, sex, breeding stage, and trip stage on the ground speeds (Vg) of four species of Southern Ocean albatrosses breeding at South Georgia. Vg was linearly related to the wind speed component in the direction of flight (Vwf), its effect being greatest on Wandering Albatrosses Diomedea exulans, followed by Black-browed Albatrosses Thalassarche melanophrys, Light-mantled Sooty Albatrosses Phoebatria palpebrata, and Gray-headed Albatrosses T. chrysostoma. Ground speeds at Vwf = 0 were similar to airspeeds predicted by aerodynamic theory and were higher in males than in females. However, we found no evidence that this led to sexual segregation, as males and females experienced comparable wind speeds during foraging trips. Black-browed, Gray-headed, and Light-mantled Sooty Albatrosses did not engage in direct, uninterrupted bouts of flight on moonless nights, but Wandering Albatrosses attained comparable Vg night and day, regardless of lunar phase. Relative flight direction was more important in determining Vg than absolute wind speed. When birds were less constrained in the middle stage of foraging trips, all species flew predominantly across the wind. However, in some instances, commuting birds encountered headwinds during outward trips and tail winds on their return, with the result that Vg was 1.0–3.4 m/s faster during return trips. This, we hypothesize, could result from constraints imposed by the location of prey resources relative to the colony at South Georgia or could represent an energy optimization strategy

SIAMESE cooperates with the CDH1-like protein CCS52A1 to establish endoreplication in Arabidopsis thaliana trichomes

Endoreplication, also known as endoreduplication, is a phyogenetically widespread modified version of the cell cycle in which DNA replication is not followed by cell division. The SIAMESE (SIM) gene of Arabidopsis thaliana encodes the founding member of a novel class of plant-specific cyclin-dependent kinase (CDK) inhibitors and is a key regulator of endoreplication during the development of trichomes (shoot epidermal hairs). Here, we have identified mutations in the CCS52A1 gene as genetic modifiers of the multicellular trichome phenotype of sim mutants. Loss-of-function ccs52A1 mutations dramatically enhance the multicellularity of sim mutants trichomes in double mutants, whereas overexpression of CCS52A1 completely suppresses the sim mutant phenotype. CCS52A1 encodes a CDH1/FZR-like protein, a class of proteins that function as activators of the anaphase-promoting complex. Unicellular ccs52A1 trichomes become multicellular upon overexpression of B-type cyclin, consistent with repression of the accumulation of mitotic cyclins in the developing trichome by CCS52A1. As these M-phase-specific cyclins are known to accumulate in sim mutant trichomes, our data suggest that CCS52A1 and SIM cooperate in repressing accumulation of mitotic cyclins to establish the trichome endocycle. Comparison with endoreplication pathways in Drosophila and mammals indicates that while these organisms all use similar components to initiate endoreplication, the components are deployed differently in each organism. Copyright © 2010 by the Genetics Society of America