991 research outputs found
The Life Cycle Stages of \u3cem\u3ePneumocystis murina\u3c/em\u3e Have Opposing Effects on the Immune Response to This Opportunistic Fungal Pathogen
The cell wall β-glucans of Pneumocystis cysts have been shown to stimulate immune responses in lung epithelial cells, dendritic cells, and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with these innate immune cells. Here we report differences in the responses of both neonatal and adult mice to the trophic and cystic life cycle stages of Pneumocystis murina. The adult and neonatal immune responses to infection with Pneumocystis murina trophic forms were less robust than the responses to infection with a physiologically normal mixture of cysts and trophic forms. Cysts promoted the recruitment of nonresident innate immune cells and T and B cells into the lungs. Cysts, but not trophic forms, stimulated increased concentrations of the cytokine gamma interferon (IFN-γ) in the alveolar spaces and an increase in the percentage of CD4+ T cells that produce IFN-γ. In vitro, bone marrow-derived dendritic cells (BMDCs) stimulated with cysts produced the proinflammatory cytokines interleukin 1β (IL-1β) and IL-6. In contrast, trophic forms suppressed antigen presentation to CD4+ T cells, as well as the β-glucan-, lipoteichoic acid (LTA)-, and lipopolysaccharide (LPS)-induced production of interleukin 1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-ι) by BMDCs. The negative effects of trophic forms were not due to ligation of mannose receptor. Our results indicate that optimal innate and adaptive immune responses to Pneumocystis species are dependent on stimulation with the cyst life cycle stage. Conversely, trophic forms suppress β-glucan-induced proinflammatory responses in vitro, suggesting that the trophic forms dampen cyst-induced inflammation in vivo
Custom Distinctions in the Interaction of G-protein β Subunits with N-type (CaV2.2) Versus P/Q-type (CaV2.1) Calcium Channels
Inhibition of N- (Cav2.2) and P/Q-type (Cav2.1) calcium channels by G-proteins contribute importantly to presynaptic inhibition as well as to the effects of opiates and cannabinoids. Accordingly, elucidating the molecular mechanisms underlying G-protein inhibition of voltage-gated calcium channels has been a major research focus. So far, inhibition is thought to result from the interaction of multiple proposed sites with the Gβγ complex (Gβγ). Far less is known about the important interaction sites on Gβγ itself. Here, we developed a novel electrophysiological paradigm, âcompound-state willing-reluctant analysis,â to describe Gβγ interaction with N- and P/Q-type channels, and to provide a sensitive and efficient screen for changes in modulatory behavior over a broad range of potentials. The analysis confirmed that the apparent (un)binding kinetics of Gβγ with N-type are twofold slower than with P/Q-type at the voltage extremes, and emphasized that the kinetic discrepancy increases up to ten-fold in the mid-voltage range. To further investigate apparent differences in modulatory behavior, we screened both channels for the effects of single point alanine mutations within four regions of Gβ1, at residues known to interact with GÎą. These residues might thereby be expected to interact with channel effectors. Of eight mutations studied, six affected G-protein modulation of both N- and P/Q-type channels to varying degrees, and one had no appreciable effect on either channel. The remaining mutation was remarkable for selective attenuation of effects on P/Q-, but not N-type channels. Surprisingly, this mutation decreased the (un)binding rates without affecting its overall affinity. The latter mutation suggests that the binding surface on Gβγ for N- and P/Q-type channels are different. Also, the manner in which this last mutation affected P/Q-type channels suggests that some residues may be important for âsteeringâ or guiding the protein into the binding pocket, whereas others are important for simply binding to the channel
The use of paraphrasing in investigative interviews
Objective
Young childrenâs descriptions of maltreatment are often sparse thus creating the need for techniques that elicit lengthier accounts. One technique that can be used by interviewers in an attempt to increase childrenâs reports is âparaphrasingâ, or repeating information children have disclosed. Although we currently have a general understanding of how paraphrasing may influence childrenâs reports, we do not have a clear description of how paraphrasing is actually used in the field.
Method
The present study assessed the use of paraphrasing in 125 interviews of children aged 4 to 16 years conducted by police officers and social workers. All interviewer prompts were coded into four different categories of paraphrasing. All childrenâs reports were coded for the number of details in response to each paraphrasing statement.
Results
âExpansion paraphrasingâ (e.g., âyou said he hit you. Tell me more about when he hit youâ) was used significantly more often and elicited significantly more details, while âyes/no paraphrasingâ (e.g., âhe hit you?â) resulted in shorter descriptions from children, compared to other paraphrasing styles. Further, interviewers more often distorted childrenâs words when using yes/no paraphrasing, and children rarely corrected interviewers when they paraphrased inaccurately.
Conclusions and Practical Implications
Investigative interviewers in this sample frequently used paraphrasing with children of all ages and, though childrenâs responses differed following the various styles of paraphrasing, the effects did not differ by the age of the child witness. The results suggest that paraphrasing affects the quality of statements by child witnesses. Implications for investigative interviewers will be discussed and recommendations offered for easy ways to use paraphrasing to increase the descriptiveness of childrenâs reports of their experiences
The Trophic Life Cycle Stage of the Opportunistic Fungal Pathogen \u3cem\u3ePneumocystis murina\u3c/em\u3e Hinders the Ability of Dendritic Cells to Stimulate CD4\u3csup\u3e+\u3c/sup\u3e T Cell Responses
The life cycle of the opportunistic fungal pathogen Pneumocystis murina consists of a trophic stage and an ascus-like cystic stage. Infection with the cyst stage induces proinflammatory immune responses, while trophic forms suppress the cytokine response to multiple pathogen-associated molecular patterns (PAMPs), including β-glucan. A targeted gene expression assay was used to evaluate the dendritic cell response following stimulation with trophic forms alone, with a normal mixture of trophic forms and cysts, or with β-glucan. We demonstrate that stimulation with trophic forms downregulated the expression of multiple genes normally associated with the response to infection, including genes encoding transcription factors. Trophic forms also suppressed the expression of genes related to antigen processing and presentation, including the gene encoding the major histocompatibility complex (MHC) class II transactivator, CIITA. Stimulation of dendritic cells with trophic forms, but not a mixture of trophic forms and cysts, reduced the expression of MHC class II and the costimulatory molecule CD40 on the surface of the cells. These defects in the expression of MHC class II and costimulatory molecules corresponded with a reduced capacity for trophic form-loaded dendritic cells to stimulate CD4+ T cell proliferation and polarization. These data are consistent with the delayed innate and adaptive responses previously observed in immunocompetent mice inoculated with trophic forms compared to responses in mice inoculated with a mixture of trophic forms and cysts. We propose that trophic forms broadly inhibit the ability of dendritic cells to fulfill their role as antigen-presenting cells
Stem cell therapy for the treatment of early stage avascular necrosis of the femoral head: a systematic review
BACKGROUND: Avascular necrosis (AVN) of the femoral head (FH) is believed to be caused by a multitude of etiologic factors and is associated with significant morbidity in younger populations. Eventually, the disease progresses and results in FH collapse. Thus, a focus on early disease management aimed at joint preservation by preventing or delaying progression is key. The use of stem cells (SC) for the treatment of AVN of the FH has been proposed. We undertook a systematic review of the medical literature examining the use of SC for the treatment of early stage (precollapse) AVN of the FH, in both pre-clinical and clinical studies. METHODS: Data collected included: Pre-clinical studies â model of AVN, variety and dosage of SC, histologic and imaging analyses. Clinical studies â study design, classification and etiology of AVN, SC dosage and treatment protocol, incidence of disease progression, patient reported outcomes, volume of necrotic lesion and hip survivorship. RESULTS: In pre-clinical studies, the use of SC uniformly demonstrated improvements in osteogenesis and angiogenesis, yet source of implanted SC was variable. In clinical studies, groups treated with SC showed significant improvements in patient reported outcomes; however hip survivorship was not affected. Discrepancies regarding dose of SC, AVN etiology and disease severity were present. CONCLUSIONS: Routine use of this treatment method will first require further research into dose and quality optimization as well as confirmed improvements in hip survivorship
ServiceNet participatory action research program evaluation : a project based on an independent investigation at ServiceNet in Northampton, MA
This research project sought to evaluate if program participants of ServiceNetâs Mental Health Recovery Services (MHRS) feel supported to meet their self defined needs and goals. These researchers were guided by the principles of Participatory Action Research (PAR) and facilitated three focus groups who designed a mixed methods survey tool to be distributed by ServiceNet Recovery Counselors. Twelve surveys were refused and returned unopened, 56 program participants received the survey envelopes and did not return them, and 34 surveys were returned completed (n=34).
Participants demonstrated high satisfaction around housing, transportation, personal growth, emotional support, feeling treated like a human being, medication information, staff training, and connection to staff. Participants reported lowest levels of need fulfillment around feeling heard if they were unsatisfied with services and feeling informed about the human rights complaint process. Qualitative analysis reveals high levels of self pathologizing attitudes, low levels of self compassion, and low levels of hope. These researchers question if greater utilization of antioppressive frameworks and practices might reduce self pathologizing perceptions and increase hope and self compassion among ServiceNet program participants. These researchers propose some project structure changes, as well as changes in demographic data collection to enable regression analyses and compare levels of satisfaction and fulfillment between different demographic variables
Environmental Drivers of the First Major Animal Extinction Across the Ediacaran White Sea-Nama Transition
The Ediacara Biota-the oldest communities of complex, macroscopic fossils-consists of three temporally distinct assemblages: the Avalon (ca. 575-560 Ma), White Sea (ca. 560-550 Ma), and Nama (ca. 550-539 Ma). Generic diversity varies among assemblages, with a notable decline at the transition from White Sea to Nama. Preservation and sampling biases, biotic replacement, and environmental perturbation have been proposed as potential mechanisms for this drop in diversity. Here, we compile a global database of the Ediacara Biota, specifically targeting taphonomic and paleoecological characters, to test these hypotheses. Major ecological shifts in feeding mode, life habit, and tiering level accompany an increase in generic richness between the Avalon and White Sea assemblages. We find that âź80% of White Sea taxa are absent from the Nama interval, comparable to loss during Phanerozoic mass extinctions. The paleolatitudes, depositional environments, and preservational modes that characterize the White Sea assemblage are well represented in the Nama, indicating that this decline is not the result of sampling bias. Counter to expectations of the biotic replacement model, there are minimal ecological differences between these two assemblages. However, taxa that disappear exhibit a variety of morphological and behavioral characters consistent with an environmentally driven extinction event. The preferential survival of taxa with high surface area relative to volume may suggest that this was related to reduced global oceanic oxygen availability. Thus, our data support a link between Ediacaran biotic turnover and environmental change, similar to other major mass extinctions in the geologic record
Learning From Summer: Effects of Voluntary Summer Learning Programs on Low-Income Urban Youth
The largest-ever study of summer learning finds that students with high attendance in free, five to six-week, voluntary summer learning programs experienced educationally meaningful benefits in math and reading.The findings are important because children from low-income families lose ground in learning over the summer compared to their more affluent peers. Voluntary, district-run summer programs could help shrink this gap and have the potential to reach more students than traditional summer school or smaller-scale programs run by outside organizations. Yet until now little has been known about the impact of these programs and how they can succeed. Wallace's $50 million National Summer Learning Project seeks to help provide answers.Since 2011, five urban school districts and their partners, the RAND Corporation and Wallace have been working together to find out whether and how voluntary-attendance summer learning programs combining academics and enrichment can help students succeed in school.Starting in 2013, RAND conducted a randomized controlled trial (RCT) in five districtsâBoston; Dallas; Duval County, Florida; Pittsburgh; and Rochesterâto evaluate educational outcomes, focusing on children who were in 3rd grade in spring of that year. The 5,600 students who applied to summer programs were randomly assigned to one of two groupsâthose selected to take part in the programs for two summers (the treatment group) and those not selected (the control group). The study analyzed outcomes for 3,192 students offered access to the programs.Researchers found that those who attended a five-to-six-week summer program for 20 or more days in 2013 did better on state math tests than similar students in the control group. This advantage was statistically significant and lasted through the following school year. The results are even more striking for high attenders in 2014: They outperformed control group students in both math and English Language Arts (ELA), on fall tests and later, in the spring. The advantage after the second summer was equivalent to 20-25 percent of a year's learning in math and ELA.These findings are correlational but controlled for prior achievement and demographics, giving researchers confidence that the benefits are likely due to the programs and meeting the requirements for promising evidence under the Every Student Succeeds Act.High-attending students were also rated by teachers as having stronger social and emotional competencies than the control group students; however, researchers have less confidence that this was due to the programs, given the lack of prior data on these competencies.About 60 percent of students attending at least one day met the 20-day threshold that was defined as high attendance.Separately, the study also examined the impact of the programs on all students who were offered access, whether or not they actually attended. Because many students did not attend at a high level, and some didn't attend at all, the average benefits for all of these students were smaller and not statistically significant, with the exception of a modest but educationally meaningful boost in math scores in the fall after the first summer equivalent to 15 percent of a year's learning. These findings are causal, meaning that researchers are confident that they were due to the programs, and meet the standard of strong evidence under the Every Student Succeeds Act.For students to experience lasting benefits from attending summer programs, the report recommends that districts: run programs for at least five weeks; promote high attendance; include sufficient instructional time and protect it; invest in instructional quality; and factor in attendance and likely no-show rates when staffing the programs in order to lower per-student costs
Constrained by managerialism : caring as participation in the voluntary social services
The data in this study show that care is a connective process, underlying and motivating participation and as a force that compels involvement in the lives of others, care is at least a micro-participative process. Care or affinity not only persisted in the face of opposition, but it was also used by workers as a counter discourse and set of practices with which to resist the erosion of worker participation and open up less autonomized practices and ways of connecting with fellow staff, clients and the communities they served. The data suggest that while managerialism and taylorised practice models may remove or reduce opportunities for worker participation, care is a theme or storyline that gave workers other ways to understand their work and why they did it, as well as ways they were prepared to resist managerial priorities and directives, including the erosion of various kinds of direct and indirect participation. The degree of resistance possible, even in the highly technocratic worksite in Australia, shows that cracks and fissures exist within managerialism
Determining the Contribution of Epidermal Cell Shape to Petal Wettability Using Isogenic Antirrhinum Lines
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
- âŚ