Novel insights into paclitaxel's role on tumor-associated macrophages in enhancing PD-1 blockade in breast cancer treatment.

BACKGROUND: Triple-negative breast cancer (TNBC) poses unique challenges due to its complex nature and the need for more effective treatments. Recent studies showed encouraging outcomes from combining paclitaxel (PTX) with programmed cell death protein-1 (PD-1) blockade in treating TNBC, although the exact mechanisms behind the improved results are unclear. METHODS: We employed an integrated approach, analyzing spatial transcriptomics and single-cell RNA sequencing data from TNBC patients to understand why the combination of PTX and PD-1 blockade showed better response in TNBC patients. We focused on toll-like receptor 4 (TLR4), a receptor of PTX, and its role in modulating the cross-presentation signaling pathways in tumor-associated macrophages (TAMs) within the tumor microenvironment. Leveraging insights obtained from patient-derived data, we conducted in vitro experiments using immunosuppressive bone marrow-derived macrophages (iBMDMs) to validate if PTX could augment the cross-presentation and phagocytosis activities. Subsequently, we extended our study to an in vivo murine model of TNBC to ascertain the effects of PTX on the cross-presentation capabilities of TAMs and its downstream impact on CD8+ T cell-mediated immune responses. RESULTS: Data analysis from TNBC patients revealed that the activation of TLR4 and cross-presentation signaling pathways are crucial for the antitumor efficacy of PTX. In vitro studies showed that PTX treatment enhances the cross-presentation ability of iBMDMs. In vivo experiments demonstrated that PTX activates TLR4-dependent cross-presentation in TAMs, improving CD8+ T cell-mediated antitumor responses. The efficacy of PTX in promoting antitumor immunity was elicited when combined with PD-1 blockade, suggesting a complementary interaction. CONCLUSIONS: This study reveals how PTX boosts the effectiveness of PD-1 inhibitors in treating TNBC. We found that PTX activates TLR4 signaling in TAMs. This activation enhances their ability to present antigens, thereby boosting CD8+ T cell antitumor responses. These findings not only shed light on PTX's immunomodulatory role in TNBC but also underscore the potential of targeting TAMs' antigen presentation capabilities in immunotherapy approaches.

A validation of the disability attitudes in health care scale using the Rasch analysis on a sample of Korean medical students.

BACKGROUND AND PURPOSE: The "Disability Attitudes in Health Care" scale contains 17 items and measures attitudes toward persons with disabilities in healthcare settings. This study aimed to analyze the psychometric properties of the Disability Attitudes in Health Care in order to improve its measurement quality. MATERIALS AND METHODS: The Disability Attitudes in Health Care scale was administered to 272 students at a medical school. Rasch analysis was conducted to assess the category use, the overall fit of the model, and the person-item fit. RESULTS: Compared to the previous 5-point Likert scoring system, the combination of category 1 (strongly disagree) and 2 (disagree), which transformed the Disability Attitudes in Health Care into a 4-point scale, was more appropriate. Items 2 and 13 had a poor fit with the model because of low construct homogeneity and low point-measure correlation, respectively; therefore, they were removed. However, there were not enough questions regarding the difficulty level for distinguishing medical students' attitudes toward persons with disabilities more sensitively. CONCLUSIONS: The results of this study suggest that constructing Disability Attitudes in Health Care with 15 items and using a 4-category scoring method could help to increase the scale's reliability and validity. The revised version of Disability Attitudes in Health Care could be of value to those who educate medical students and train rehabilitation professionals. IMPLICATIONS FOR REHABILITATIONConstructing a Disability Attitudes in Health Care scale with 15 items by using a 4-category scoring method could increase the reliability and validity of the scale.To improve the sensitivity of the Disability Attitudes in Health Care, it is necessary to add more difficult items to the scale.The Disability Attitudes in Health Care could be of value to those who educate medical students and train rehabilitation professionals.

Evaluation of interprofessional health care team communication simulation in geriatric palliative care.

An interprofessional education (IPE) simulation-based geriatric palliative care training was developed to educate health professions students in team communication. In health care, interprofessional communication is critical to team collaboration and patient and family caregiver outcomes. Studies suggest that acquiring skills to work on health care teams and communicate with team members should occur during the early stage of professional education. The Interprofessional Education Collaborative (IPEC®) competency-based framework was used to inform the training. An evaluation examined attitudes toward health care teams, self-efficacy in communication skills, interprofessional collaboration, and participant satisfaction with the training experience. One-hundred and eleven participants completed pre- and post-training surveys. Overall, a majority of participants (97.3%) were satisfied with the training and reported more positive attitudes toward health care teams and greater self-efficacy in team communication skills. IPE participants had higher collaboration scores compared to observer learners. Further research is needed to explore long-term effects of IPE in clinical practice.

Key determinants to using telehealth technology to serve medically ill and depressed homebound older adults.

Despite the increasing evidence for the effectiveness of telehealth technology in screening and treating chronic diseases, and comorbid depression among older adults, they have been slowly adopted by home health care (HHC) agencies. Therefore, this study aimed to identify factors that determine telehealth technology adoption. Twenty directors from the National Association for Homecare & Hospice member agencies completed a 45-min telephone interview. Questions were asked regarding their perceptions of telehealth, the key determinants of telehealth adoption and use, and recommendations they would give on telehealth adoption. The majority of the participants perceived telehealth as effective for managing symptoms and reducing cost. Meanwhile, some participants had a mixed feeling toward telehealth for depression care as they did not recognize their agency as equipped with the necessary resources and trained staff. Moreover, significant determinants of telehealth adoption included the agency-related characteristics, the patient-home environment, reimbursement and cost-related factors, and staff telehealth perception. Findings imply that there is a need for financial support both at the state and the federal levels to encourage telehealth adoption among HHC agencies. Future studies should consider exploring strategies used by successful programs to overcome barriers.

Training social work students to recognize later-life depression: Is standardized patient simulation effective?

Professional social workers are the largest provider of mental health services in the nation, yet they receive little coursework or clinical training in late-life depression unless they are in a gerontology specialization. Simulation training offers academic experiences that evoke conditions of the real world in a practical way. One hundred and four graduate social work students consented and completed the Standardized Patient Simulation course consisting of a human simulator interview, pre- and postdebriefing on late life depression, and self and faculty ratings of outcome measures. Results from pre-post testing of measures and the debriefing evaluation demonstrated that students gained in knowledge and achieved clinical skill competency. Students reported that the patient simulator was convincing, the environment was realistic, and they were satisfied with the training. The educational methodology tests students in challenging situations and offers immediate educational feedback to integrate and improve practice behaviors towards achieving clinical competency.

Illuminating structural proteins in viral "dark matter" with metaproteomics.

Viruses are ecologically important, yet environmental virology is limited by dominance of unannotated genomic sequences representing taxonomic and functional "viral dark matter." Although recent analytical advances are rapidly improving taxonomic annotations, identifying functional dark matter remains problematic. Here, we apply paired metaproteomics and dsDNA-targeted metagenomics to identify 1,875 virion-associated proteins from the ocean. Over one-half of these proteins were newly functionally annotated and represent abundant and widespread viral metagenome-derived protein clusters (PCs). One primarily unannotated PC dominated the dataset, but structural modeling and genomic context identified this PC as a previously unidentified capsid protein from multiple uncultivated tailed virus families. Furthermore, four of the five most abundant PCs in the metaproteome represent capsid proteins containing the HK97-like protein fold previously found in many viruses that infect all three domains of life. The dominance of these proteins within our dataset, as well as their global distribution throughout the world's oceans and seas, supports prior hypotheses that this HK97-like protein fold is the most abundant biological structure on Earth. Together, these culture-independent analyses improve virion-associated protein annotations, facilitate the investigation of proteins within natural viral communities, and offer a high-throughput means of illuminating functional viral dark matter.

Telehealth Utilization for Chronic Illness and Depression Among Home Health Agencies: A Pilot Survey.

This pilot survey study explores current telehealth use among home health care agencies for chronic illness and depression care, and identifies factors associated with agencies' perception and intention to use telehealth. Between June and August 2014, 73 directors and 13 staff nurses (N = 86) from the Pennsylvania Homecare Association member agencies participated in an online survey. Eighty-five percent of telehealth provider agencies reported utilizing telehealth for monitoring health status while only 7.7% reported use for depression care. Telehealth technology was more positively perceived for chronic illness care (90.7%) than for depression care (53%) services. Factors associated with positive perceptions of telehealth were identified, including: (a) intention to use or continuing to use telehealth, (b) the size of the agency, (c) the participant's agency role, and (d) existence of depression services. These pilot findings have been used to inform the theoretical framework and the survey instrument for our U.S. national survey.

Methane dynamics regulated by microbial community response to permafrost thaw.

Permafrost contains about 50% of the global soil carbon. It is thought that the thawing of permafrost can lead to a loss of soil carbon in the form of methane and carbon dioxide emissions. The magnitude of the resulting positive climate feedback of such greenhouse gas emissions is still unknown and may to a large extent depend on the poorly understood role of microbial community composition in regulating the metabolic processes that drive such ecosystem-scale greenhouse gas fluxes. Here we show that changes in vegetation and increasing methane emissions with permafrost thaw are associated with a switch from hydrogenotrophic to partly acetoclastic methanogenesis, resulting in a large shift in the δ(13)C signature (10-15‰) of emitted methane. We used a natural landscape gradient of permafrost thaw in northern Sweden as a model to investigate the role of microbial communities in regulating methane cycling, and to test whether a knowledge of community dynamics could improve predictions of carbon emissions under loss of permafrost. Abundance of the methanogen Candidatus 'Methanoflorens stordalenmirensis' is a key predictor of the shifts in methane isotopes, which in turn predicts the proportions of carbon emitted as methane and as carbon dioxide, an important factor for simulating the climate feedback associated with permafrost thaw in global models. By showing that the abundance of key microbial lineages can be used to predict atmospherically relevant patterns in methane isotopes and the proportion of carbon metabolized to methane during permafrost thaw, we establish a basis for scaling changing microbial communities to ecosystem isotope dynamics. Our findings indicate that microbial ecology may be important in ecosystem-scale responses to global change.

Discovery of a novel methanogen prevalent in thawing permafrost.

Thawing permafrost promotes microbial degradation of cryo-sequestered and new carbon leading to the biogenic production of methane, creating a positive feedback to climate change. Here we determine microbial community composition along a permafrost thaw gradient in northern Sweden. Partially thawed sites were frequently dominated by a single archaeal phylotype, Candidatus 'Methanoflorens stordalenmirensis' gen. nov. sp. nov., belonging to the uncultivated lineage 'Rice Cluster II' (Candidatus 'Methanoflorentaceae' fam. nov.). Metagenomic sequencing led to the recovery of its near-complete genome, revealing the genes necessary for hydrogenotrophic methanogenesis. These genes are highly expressed and methane carbon isotope data are consistent with hydrogenotrophic production of methane in the partially thawed site. In addition to permafrost wetlands, 'Methanoflorentaceae' are widespread in high methane-flux habitats suggesting that this lineage is both prevalent and a major contributor to global methane production. In thawing permafrost, Candidatus 'M. stordalenmirensis' appears to be a key mediator of methane-based positive feedback to climate warming.

A periplasmic arsenite-binding protein involved in regulating arsenite oxidation.

Arsenic (As) is the most common toxic element in the environment, ranking first on the Superfund List of Hazardous Substances. Microbial redox transformations are the principal drivers of As chemical speciation, which in turn dictates As mobility and toxicity. Consequently, in order to manage or remediate environmental As, land managers need to understand how and why microorganisms react to As. Studies have demonstrated a two-component signal transduction system comprised of AioS (sensor kinase) and AioR (response regulator) is involved in regulating microbial AsIII oxidation, with the AsIII oxidase structural genes aioB and aioA being upregulated by AsIII. However, it is not known whether AsIII is first detected directly by AioS or by an intermediate. Herein we demonstrate the essential role of a periplasmic AsIII-binding protein encoded by aioX, which is upregulated by AsIII. An ΔaioX mutant is defective for upregulation of the aioBA genes and consequently AsIII oxidation. Purified AioX expressed without its TAT-type signal peptide behaves as a monomer (MW 32 kDa), and Western blots show AioX to be exclusively associated with the cytoplasmic membrane. AioX binds AsIII with a K(D) of 2.4 µM AsIII; however, mutating a conserved Cys108 to either alanine or serine resulted in lack of AsIII binding, lack of aioBA induction, and correlated with a negative AsIII oxidation phenotype. The discovery and characterization of AioX illustrates a novel AsIII sensing mechanism that appears to be used in a range of bacteria and also provides one of the first examples of a bacterial signal anchor protein.

Switch or funnel: how RND-type transport systems control periplasmic metal homeostasis.

Bacteria have evolved several transport mechanisms to maintain metal homeostasis and to detoxify the cell. One mechanism involves an RND (resistance-nodulation-cell division protein family)-driven tripartite protein complex to extrude a variety of toxic substrates to the extracellular milieu. These efflux systems are comprised of a central RND proton-substrate antiporter, a membrane fusion protein, and an outer membrane factor. The mechanism of substrate binding and subsequent efflux has yet to be elucidated. However, the resolution of recent protein crystal structures and genetic analyses of the components of the heavy-metal efflux family of RND proteins have allowed the developments of proposals for a substrate transport pathway. Here two models of substrate extrusion through RND protein complexes of the heavy-metal efflux protein family are described. The funnel model involves the shuttling of periplasmic substrate from the membrane fusion protein to the RND transporter and further on through the outer membrane factor to the extracellular space. Conversely, the switch model requires substrate binding to the membrane fusion protein, inducing a conformational change and creating an open-access state of the tripartite protein complex. The extrusion of periplasmic substrate bypasses the membrane fusion protein, enters the RND-transporter directly via its substrate-binding site, and is ultimately eliminated through the outer membrane channel. Evidence for and against the two models is described, and we propose that current data favor the switch model.

Differing ability to transport nonmetal substrates by two RND-type metal exporters.

The metal-exporting systems CusCFBA of Escherichia coli and GesABC of Salmonella are resistance-nodulation-division (RND)-type multiprotein systems responsible for detoxification during metal stress. In this study, the substrate range was determined for each metal transport system and possible amino acid residues important in substrate specificity were identified. The Ges system, previously identified as a gold-efflux system, conferred resistance to the greatest number and variety of organic chemicals including chloramphenicol, not recognized previously as a substrate. Phylogenetic analysis showed that GesB is most closely related to a class of RND transporters including MexF that have been shown to be responsible for exporting fluoroquinolones, chloramphenicol, and biocides. However, many of the closest homologs of GesABC appear to play a role in metal resistance judging from the genetic context. In contrast, CusCFBA belongs to a distinct family of RND-type monovalent metal-exporter systems containing a number of essential metal-binding methionines, resulting in a much narrower substrate range.

Mu and kappa opioids modulate mouse embryonic stem cell-derived neural progenitor differentiation via MAP kinases.

As embryonic stem cell-derived neural progenitors (NPs) have the potential to be used in cell replacement therapy, an understanding of the signaling mechanisms that regulate their terminal differentiation is imperative. In previous studies, we discovered the presence of functional mu opioid receptors (MOR) and kappa opioid receptors (KOR) in mouse embryonic stem cells and NPs. Here, MOR and KOR immunoreactivity was detected in NP-derived oligodendrocytes during three stages of their maturation in vitro. Moreover, we examined the modulation of retinoic acid-induced NP differentiation to astrocytes and neurons by mu, [D-ala(2), mephe(4), gly-ol(5)] enkephalin, or kappa, U69, 593, opioids. Both opioid agonists inhibited NP-derived neurogenesis and astrogenesis via their corresponding receptors as determined by immunocytochemistry. By administering selective inhibitors, we found that opioid inhibition of NP-derived astrogenesis was driven via extracellular-signal regulated kinase (ERK), while the p38 mitogen-activated protein kinase pathway was implicated in opioid attenuation of neurogenesis. In addition, mu and kappa opioids stimulated oligodendrogenesis from NP-derived NG2(+) oligodendrocyte progenitors via both ERK and p38 signaling pathways. Accordingly, both opioids induced ERK phosphorylation in NG2(+) cells. These results indicate that small molecules, such as MOR and KOR agonists may play a modulatory role in NP terminal differentiation.

The metal efflux island of Legionella pneumophila is not required for survival in macrophages and amoebas.

Legionella pneumophila is an intracellular pathogen causing pneumonia-like disease in humans. A 43-kb putative heavy metal efflux gene island was found on the L. pneumophila genome. Large Legionella deletion strains of the metal efflux genes were tested in human THP-1-derived macrophages and amoebal Acanthamoeba castellanii cells and were able to survive and replicate similar to the wild type, suggesting that they do not play a significant role within the intracellular environment. Examination of the sequence of this genomic island revealed that some genes were not accurately annotated and there were no known metal-responsive regulators encoded in this region. Therefore, functional roles of these metal resistance genes were tested by conducting metal resistance assays. Individual genes were cloned in an expression vector and expressed in an appropriate metal-sensitive Escherichia coli background with varying concentrations of the tested metal. Of the 11 efflux systems, a role was determined only for one. A Cu(I)-translocating P(IB)-type ATPase was shown to be encoded by lpg1024. This gene, termed copA, complemented a copper-sensitive (Delta copA) E. coli strain in trans and was able to confer copper resistance.

Mu- and kappa-opioids induce the differentiation of embryonic stem cells to neural progenitors.

Growth factors, hormones, and neurotransmitters have been implicated in the regulation of stem cell fate. Since various neural precursors express functional neurotransmitter receptors, which include G protein-coupled receptors, it is anticipated that they are involved in cell fate decisions. We detected mu-opioid receptor (MOR-1) and kappa-opioid receptor (KOR-1) expression and immunoreactivity in embryonic stem (ES) cells and in retinoic acid-induced ES cell-derived, nestin-positive, neural progenitors. Moreover, these G protein-coupled receptors are functional, since [D-Ala(2),MePhe(4),Gly-ol(5)]enkephalin, a MOR-selective agonist, and U69,593, a KOR-selective agonist, induce a sustained activation of extracellular signal-regulated kinase (ERK) signaling throughout a 24-h treatment period in undifferentiated, self-renewing ES cells. Both opioids promote limited proliferation of undifferentiated ES cells via the ERK/MAP kinase signaling pathway. Importantly, biochemical and immunofluorescence data suggest that [D-Ala(2),MePhe(4),Gly-ol(5)]enkephalin and U69,593 divert ES cells from self-renewal and coax the cells to differentiate. In retinoic acid-differentiated ES cells, opioid-induced signaling features a biphasic ERK activation profile and an opioid-induced, ERK-independent inhibition of proliferation in these neural progenitors. Collectively, the data suggest that opioids may have opposite effects on ES cell self-renewal and ES cell differentiation and that ERK activation is only required by the latter. Finally, opioid modulation of ERK activity may play an important role in ES cell fate decisions by directing the cells to specific lineages.

Expression of thymosin beta in the rat brain following transient global ischemia.

Thymosin beta (Tbeta) isoforms play an important role in the organization of the cytoskeleton by sequestering G-actin during development of the mammalian brain. In this study, we examined changes in the expression of Tbeta4 and Tbeta15 after transient global ischemia. Tbeta15 mRNA increased gradually in the dentate gyrus (DG) of the hippocampal formation from 3 h after reperfusion and peaked 9 h later. Similarly, a significant increase in Tbeta4 mRNA level was observed in the DG 12 h after reperfusion. Tbeta4 and Tbeta15 proteins were found in different cell types in control brains; Tbeta15 was expressed in a subset of doublecortin (DCX)-positive cells in the DG, whereas Tbeta4-IR was observed in DG neurons and nearby microglial cells. After ischemia, Tbeta15-IR was found in DG neurons and Tbeta4-IR in the reactivated microglial cells. Interestingly, Tbeta15-IR accumulated in the nuclei of CA1 neurons, which are vulnerable to ischemic insults. These results suggest that Tbeta4 and Tbeta15 function in different cellular contexts during ischemia-induced responses.