RESUMO
Malingering is characterized by the deliberate fabrication and/or exaggeration of symptoms for secondary gain, posing a diagnostic challenge in healthcare settings. In this report, we present a 15-year-old male with a history of psychiatric disorders who attempted suicide to avoid legal sentencing, subsequently developing a stutter following an altercation with another patient. Despite initial concern for a concussion, further evaluation revealed malingering as the underlying motive. This case highlights the importance of identifying malingering in adolescents, which calls for a careful approach and thorough assessment for it to be distinguished from an authentic illness. Early identification of malingering optimizes resource allocation and ensures appropriate care for patients who have genuine medical needs.
RESUMO
Marine biogeochemical cycles are built on interactions between surface ocean microbes, particularly those connecting phytoplankton primary producers to heterotrophic bacteria. Details of these associations are not well understood, especially in the case of direct influences of bacteria on phytoplankton physiology. Here we catalogue how the presence of three marine bacteria (Ruegeria pomeroyi DSS-3, Stenotrophomonas sp. SKA14 and Polaribacter dokdonensis MED152) individually and uniquely impact gene expression of the picoeukaryotic alga Micromonas commoda RCC 299. We find a dramatic transcriptomic remodelling by M. commoda after 8 h in co-culture, followed by an increase in cell numbers by 56 h compared with the axenic cultures. Some aspects of the algal transcriptomic response are conserved across all three bacterial co-cultures, including an unexpected reduction in relative expression of photosynthesis and carbon fixation pathways. Expression differences restricted to a single bacterium are also observed, with the Flavobacteriia P. dokdonensis uniquely eliciting changes in relative expression of algal genes involved in biotin biosynthesis and the acquisition and assimilation of nitrogen. This study reveals that M. commoda has rapid and extensive responses to heterotrophic bacteria in ways that are generalizable, as well as in a taxon specific manner, with implications for the diversity of phytoplankton-bacteria interactions ongoing in the surface ocean.
Assuntos
Fotossíntese , Transcriptoma , Fitoplâncton/genética , Fitoplâncton/metabolismo , Clorófitas/genética , Clorófitas/metabolismo , Clorófitas/microbiologia , Bactérias/genética , Bactérias/classificação , Bactérias/metabolismo , Processos Heterotróficos , Água do Mar/microbiologiaRESUMO
Dissolved primary production released into seawater by marine phytoplankton is a major source of carbon fueling heterotrophic bacterial production in the ocean. The composition of the organic compounds released by healthy phytoplankton is poorly known and difficult to assess with existing chemical methods. Here, expression of transporter and catabolic genes by three model marine bacteria (Ruegeria pomeroyi DSS-3, Stenotrophomonas sp. SKA14, and Polaribacter dokdonensis MED152) was used as a biological sensor of metabolites released from the picoeukaryote Micromonas commoda RCC299. Bacterial expression responses indicated that the three species together recognized 38 picoeukaryote metabolites. This was consistent with the Micromonas expression of genes for starch metabolism and synthesis of peptidoglycan-like intermediates. A comparison of the hypothesized Micromonas exometabolite pool with that of the diatom Thalassiosira pseudonana CCMP1335, analyzed previously with the same biological sensor method, indicated that both phytoplankton released organic acids, nucleosides, and amino acids, but differed in polysaccharide and organic nitrogen release. Future ocean conditions are expected to favor picoeukaryotic phytoplankton over larger-celled microphytoplankton. Results from this study suggest that such a shift could alter the substrate pool available to heterotrophic bacterioplankton.
RESUMO
PROBLEM: Few interprofessional development programs focused on learning knowledge and skills in health systems science (HSS) have been described. The authors implemented a professional development program (the HSS Academy) for interprofessional clinicians and trainees. The authors describe the HSS Academy, report preliminary outcomes, and describe strategies for use in other programs. APPROACH: The HSS Academy (an 8-month active learning classroom and project-based curriculum) was implemented at Penn State College of Medicine in 2015. To create an interprofessional environment, participants were selected from various professions and phases of training. The curriculum was anchored in HSS competencies (e.g., high-value care, quality improvement, social determinants of health, health system strategy and delivery) and included 2 distinct threads focused on systems thinking competencies and academic skill development. It featured course speakers and faculty from diverse roles and disciplines both inside and outside the health system, application of HSS competencies in local system contexts, and networking with interprofessional colleagues. OUTCOMES: From 2015 to 2021, 121 of 128 participants, including physicians, medical students, and nurses, completed the HSS Academy (95% completion rate). Over 90 individuals, including faculty and system leaders, contributed to the HSS Academy as educators. Comparisons of pre-post evaluations demonstrated statistically significant self-perceived improvements in HSS knowledge and skills, systems thinking, and HSS teaching knowledge and skills. Projects (n = 110) most commonly focused on health care delivery, quality improvement, or patient safety. Teaching strategies to meet each objective, several barriers encountered, and strategies to address those barriers are described. NEXT STEPS: Next steps will be to address financial support for creating and sustaining the HSS Academy, ensure a mutually shared understanding of the HSS Academy's goals among all stakeholders, facilitate meaningful change from scholars' work, and provide networking and opportunities for scholars to continue work in HSS after completion of the HSS Academy.
Assuntos
Educação Médica , Estudantes de Medicina , Humanos , Programas Governamentais , Currículo , Docentes de MedicinaRESUMO
The colonization of land by plants generated opportunities for the rise of new heterotrophic life forms, including humankind. A unique event underpinned this massive change to earth ecosystems-the advent of eukaryotic green algae. Today, an abundant marine green algal group, the prasinophytes, alongside prasinodermophytes and nonmarine chlorophyte algae, is facilitating insights into plant developments. Genome-level data allow identification of conserved proteins and protein families with extensive modifications, losses, or gains and expansion patterns that connect to niche specialization and diversification. Here, we contextualize attributes according to Viridiplantae evolutionary relationships, starting with orthologous protein families, and then focusing on key elements with marked differentiation, resulting in patchy distributions across green algae and plants. We place attention on peptidoglycan biosynthesis, important for plastid division and walls; phytochrome photosensors that are master regulators in plants; and carbohydrate-active enzymes, essential to all manner of carbohydratebiotransformations. Together with advances in algal model systems, these areas are ripe for discovering molecular roles and innovations within and across plant and algal lineages.
Assuntos
Clorófitas , Viridiplantae , Clorófitas/genética , Clorófitas/metabolismo , Ecossistema , Evolução Molecular , Filogenia , Plantas/genética , Viridiplantae/genéticaRESUMO
The Andvord fjord in the West Antarctic Peninsula (WAP) is known for its productivity and abundant megafauna. Nevertheless, seasonal patterns of the molecular diversity and abundance of protistan community members underpinning WAP productivity remain poorly resolved. We performed spring and fall expeditions pursuing protistan diversity, abundance of photosynthetic taxa, and the connection to changing conditions. 18S rRNA amplicon sequence variant (ASV) profiles revealed diverse predatory protists spanning multiple eukaryotic supergroups, alongside enigmatic heterotrophs like the Picozoa. Among photosynthetic protists, cryptophyte contributions were notable. Analysis of plastid-derived 16S rRNA ASVs supported 18S ASV results, including a dichotomy between cryptophytes and diatom contributions previously reported in other Antarctic regions. We demonstrate that stramenopile and cryptophyte community structures have distinct attributes. Photosynthetic stramenopiles exhibit high diversity, with the polar diatom Fragilariopsis cylindrus, unidentified Chaetoceros species, and others being prominent. Conversely, ASV analyses followed by environmental full-length rRNA gene sequencing, electron microscopy, and flow cytometry revealed that a novel alga dominates the cryptophytes. Phylogenetic analyses established that TPG clade VII, as named here, is evolutionarily distinct from cultivated cryptophyte lineages. Additionally, cryptophyte cell abundance correlated with increased water temperature. Analyses of global data sets showed that clade VII dominates cryptophyte ASVs at Southern Ocean sites and appears to be endemic, whereas in the Arctic and elsewhere, Teleaulax amphioxeia and Plagioselmis prolonga dominate, although both were undetected in Antarctic waters. Collectively, our studies provide baseline data against which future change can be assessed, identify different diversification patterns between stramenopiles and cryptophytes, and highlight an evolutionarily distinct cryptophyte clade that thrives under conditions enhanced by warming. IMPORTANCE The climate-sensitive waters of the West Antarctic Peninsula (WAP), including its many fjords, are hot spots of productivity that support multiple marine mammal species. Here, we profiled protistan molecular diversity in a WAP fjord known for high productivity and found distinct spatiotemporal patterns across protistan groups. Alongside first insights to seasonal changes in community structure, we discovered a novel phytoplankton species with proliferation patterns linked to temperature shifts. We then examined evolutionary relationships between this novel lineage and other algae and their patterns in global ocean survey data. This established that Arctic and Antarctic cryptophyte communities have different species composition, with the newly identified lineage being endemic to Antarctic waters. Our research provides critical knowledge on how specific phytoplankton at the base of Antarctic food webs respond to warming, as well as information on overall diversity and community structure in this changing polar environment.
Assuntos
Biodiversidade , Fitoplâncton/isolamento & purificação , Regiões Antárticas , Criptófitas/classificação , Criptófitas/genética , Criptófitas/isolamento & purificação , Estuários , Filogenia , Fitoplâncton/classificação , Fitoplâncton/genética , Plastídeos/classificação , Plastídeos/genética , Estações do Ano , Estramenópilas/classificação , Estramenópilas/genética , Estramenópilas/isolamento & purificaçãoRESUMO
Coral reefs are possible sinks for microbes; however, the removal mechanisms at play are not well understood. Here, we characterize pelagic microbial groups at the CARMABI reef (Curaçao) and examine microbial consumption by three coral species: Madracis mirabilis, Porites astreoides, and Stephanocoenia intersepta Flow cytometry analyses of water samples collected from a depth of 10 m identified 6 microbial groups: Prochlorococcus, three groups of Synechococcus, photosynthetic eukaryotes, and heterotrophic bacteria. Minimum growth rates (µ) for Prochlorococcus, all Synechococcus groups, and photosynthetic eukaryotes were 0.55, 0.29, and 0.45 µ day-1, respectively, and suggest relatively high rates of productivity despite low nutrient conditions on the reef. During a series of 5-h incubations with reef corals performed just after sunset or prior to sunrise, reductions in the abundance of photosynthetic picoeukaryotes, Prochlorococcus and Synechococcus cells, were observed. Of the three Synechococcus groups, one decreased significantly during incubations with each coral and the other two only with M. mirabilis. Removal of carbon from the water column is based on coral consumption rates of phytoplankton and averaged between 138 ng h-1 and 387 ng h-1, depending on the coral species. A lack of coral-dependent reduction in heterotrophic bacteria, differences in Synechococcus reductions, and diurnal variation in reductions of Synechococcus and Prochlorococcus, coinciding with peak cell division, point to selective feeding by corals. Our study indicates that bentho-pelagic coupling via selective grazing of microbial groups influences carbon flow and supports heterogeneity of microbial communities overlying coral reefs.IMPORTANCE We identify interactions between coral grazing behavior and the growth rates and cell abundances of pelagic microbial groups found surrounding a Caribbean reef. During incubation experiments with three reef corals, reductions in microbial cell abundance differed according to coral species and suggest specific coral or microbial mechanisms are at play. Peaks in removal rates of Prochlorococcus and Synechococcus cyanobacteria appear highest during postsunset incubations and coincide with microbial cell division. Grazing rates and effort vary across coral species and picoplankton groups, possibly influencing overall microbial composition and abundance over coral reefs. For reef corals, use of such a numerically abundant source of nutrition may be advantageous, especially under environmentally stressful conditions when symbioses with dinoflagellate algae break down.
Assuntos
Antozoários/fisiologia , Bactérias/crescimento & desenvolvimento , Recifes de Corais , Eucariotos/crescimento & desenvolvimento , Microbiota , Animais , Região do Caribe , Água do Mar/microbiologia , Microbiologia da ÁguaRESUMO
This article describes the development of a scoring system for general surgical patients to highlight those at greater risk of developing acute kidney injury (AKI). Following a search of the literature on current practice, a list of common variables was composed. Hospital Episode Statistics (HES) data from two random hospital trusts was used. With the help of a risk analysis system (CRAB Medical module, CRAB Clinical Informatics Ltd) it was possible to examine the relationship between potential risk factors and the incidence of AKI. Using Analyse-it for Excel a binary logistic model was created, which led to the development of a logistic regression equation and consequently a scoring system. The sensitivity and specificity of the model was tested using the receiver operating characteristic (ROC) curve. There was good correlation across the whole risk spectrum with an area under ROC curve of 0.806 (95% confidence intervals 0.787-0.825). The scoring system was developed into an admission checklist for general surgical patients to highlight a patient's risk of developing AKI. In a ward setting a checklist that immediately assesses the patient and produces a rapid indication as to whether the patient is at high risk or low risk would seem to be the ideal tool.
Assuntos
Injúria Renal Aguda/epidemiologia , Medição de Risco/métodos , Procedimentos Cirúrgicos Operatórios/efeitos adversos , HumanosRESUMO
Photosynthesis in eukaryotes first arose through phagocytotic processes wherein an engulfed cyanobacterium was not digested, but instead became a permanent organelle. Other photosynthetic lineages then arose when eukaryotic cells engulfed other already photosynthetic eukaryotic cells. Some of the resulting lineages subsequently lost their ability for phagocytosis, while many others maintained the ability to do both processes. These mixotrophic taxa have more complicated ecological roles, in that they are both primary producers and consumers that can shift more towards producing the organic matter that forms the base of aquatic food chains, or towards respiring and releasing CO2. We still have much to learn about which taxa are predatory mixotrophs as well as about the physiological consequences of this lifestyle, in part, because much of the diversity of unicellular eukaryotes in aquatic ecosystems remains uncultured. Here, we discuss existing methods for studying predatory mixotrophs, their individual biases, and how single-cell approaches can enhance knowledge of these important taxa. The question remains what the gold standard should be for assigning a mixotrophic status to ill-characterized or uncultured taxa-a status that dictates how organisms are incorporated into carbon cycle models and how their ecosystem roles may shift in future lakes and oceans. This article is part of a discussion meeting issue 'Single cell ecology'.
Assuntos
Ecologia/métodos , Eucariotos/fisiologia , Características de História de Vida , Biologia Marinha/métodos , Análise de Célula Única/métodosRESUMO
PURPOSE: To develop a potential competency framework for faculty development programs aligned with the needs of faculty in academic health centers (AHCs). METHOD: In 2014 and 2015, the authors interviewed 23 health system leaders and analyzed transcripts using constant comparative analysis and thematic analysis. They coded competencies and curricular concepts into subcategories. Lead investigators reviewed drafts of the categorization themes and subthemes related to gaps in faculty knowledge and skills, collapsed and combined competency domains, and resolved disagreements via discussion. RESULTS: Through analysis, the authors identified four themes. The first was core functional competencies and curricular domains for conceptual learning, including patient-centered care, health care processes, clinical informatics, population and public health, policy and payment, value-based care, and health system improvement. The second was the need for foundational competency domains, including systems thinking, change agency/management, teaming, and leadership. The third theme was paradigm shifts in how academic faculty should approach health care, categorized into four areas: delivery, transformation, provider characteristics and skills, and education. The fourth theme was the need for faculty to be aware of challenges in the culture of AHCs as an influential context for change. CONCLUSIONS: This broad competency framework for faculty development programs expands existing curricula by including a comprehensive scope of health systems science content and skills. AHC leaders can use these results to better align faculty education with the real-time needs of their health systems. Future work should focus on optimal prioritization and methods for teaching.
Assuntos
Educação Médica , Docentes de Medicina/educação , Competência Profissional , Centros Médicos Acadêmicos , Currículo , Atenção à Saúde , Humanos , Liderança , Informática Médica , Modelos Psicológicos , Avaliação das Necessidades , Pesquisa Qualitativa , Desenvolvimento de PessoalRESUMO
Vitamin B1 (thiamin) is a cofactor for critical enzymatic processes and is scarce in surface oceans. Several eukaryotic marine algal species thought to rely on exogenous thiamin are now known to grow equally well on the precursor 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP), including the haptophyte Emiliania huxleyi Because the thiamin biosynthetic capacities of the diverse and ecologically important haptophyte lineage are otherwise unknown, we investigated the pathway in transcriptomes and two genomes from 30 species representing six taxonomic orders. HMP synthase is missing in data from all studied taxa, but the pathway is otherwise complete, with some enzymatic variations. Experiments on axenic species from three orders demonstrated that equivalent growth rates were supported by 1 µM HMP or thiamin amendment. Cellular thiamin quotas were quantified in the oceanic phytoplankter E. huxleyi using the thiochrome assay. E. huxleyi exhibited luxury storage in standard algal medium [(1.16 ± 0.18) × 10-6 pmol thiamin cell-1], whereas quotas in cultures grown under more environmentally relevant thiamin and HMP supplies [(2.22 ± 0.07) × 10-7 or (1.58 ± 0.14) × 10-7 pmol thiamin cell-1, respectively] were significantly lower than luxury values and prior estimates. HMP and its salvage-related analog 4-amino-5-aminomethyl-2-methylpyrimidine (AmMP) supported higher growth than thiamin under environmentally relevant supply levels. These compounds also sustained growth of the stramenopile alga Pelagomonas calceolata Together with identification of a salvage protein subfamily (TENA_E) in multiple phytoplankton, the results indicate that salvaged AmMP and exogenously acquired HMP are used by several groups for thiamin production. Our studies highlight the potential importance of thiamin pathway intermediates and their analogs in shaping phytoplankton community structure.IMPORTANCE The concept that vitamin B1 (thiamin) availability in seawater controls the productivity and structure of eukaryotic phytoplankton communities has been discussed for half a century. We examined B1 biosynthesis and salvage pathways in diverse phytoplankton species. These comparative genomic analyses as well as experiments show that phytoplankton thought to require exogenous B1 not only utilize intermediate compounds to meet this need but also exhibit stronger growth on these compounds than on thiamin. Furthermore, oceanic phytoplankton have lower cellular thiamin quotas than previously reported, and salvage of intermediate compounds is likely a key mechanism for meeting B1 requirements under environmentally relevant scenarios. Thus, several lines of evidence now suggest that availability of specific precursor molecules could be more important in structuring phytoplankton communities than the vitamin itself. This understanding of preferential compound utilization and thiamin quotas will improve biogeochemical model parameterization and highlights interaction networks among ocean microbes.
Assuntos
Haptófitas/metabolismo , Pirimidinas/metabolismo , Água do Mar/química , Água do Mar/microbiologia , Tiamina/metabolismo , Meios de Cultura , Genoma , Haptófitas/genética , Haptófitas/crescimento & desenvolvimento , Redes e Vias Metabólicas , Oceanos e Mares , Tiamina/biossíntese , TranscriptomaRESUMO
This study aimed to develop and evaluate resin-based experimental dental sealants containing electrospun nylon-6 (N6) and chitosan (CH) fibers in an attempt to improve the physicomechanical properties and provide an antibacterial protective effect, respectively. Electrospun N6 and CH mats were immersed into a resin mixture, light-cured, and then cryomilled to obtain micron-sized resin-modified fiber particles. Different levels of the novel cryomilled particles (i.e. 1, 2.5, and 5% relative to the resin mixture, % by weight) were used to prepare the N6- and CH-containing sealants. A commercial sealant and the experimental resin mixture (unfilled) were used as controls. Flexural strength (FS), Vickers microhardness (VH), and agar diffusion tests were performed. The data were analyzed at the 5% significance level. No significant difference in fiber diameter of N6 (503 ± 31 nm) and CH (595 ± 38 nm) was observed. Upon cryomilling, the resin-modified CH and N6 mats led to the formation of irregularly-shaped particles, with an average diameter of 14.24 µm and 15.87 µm, respectively. CH-5% had significantly higher FS (115.3 ± 1.3 MPa) than all the other groups. CH-1% had significantly higher hardness values (38.3 ± 0.3 VHN) than all the other groups. Collectively, the results indicated that CH-containing sealants presented the highest FS and hardness; however, none of the CH-containing sealants displayed antimicrobial properties.
Assuntos
Antibacterianos/química , Caprolactama/análogos & derivados , Quitosana/química , Nanofibras/química , Selantes de Fossas e Fissuras/química , Polímeros/química , Caprolactama/químicaRESUMO
BACKGROUND: This study assesses the impact that a resident oversight and credentialing policy for central venous catheter (CVC) placement had on institution-wide central line associated bloodstream infections (CLABSI). We therefore investigated the rate of CLABSI per 1,000 line days during the 12 months before and after implementation of the policy. METHODS: This is a retrospective analysis of prospectively collected data at an academic medical center with four adult ICUs and a pediatric ICU. All patients undergoing non-tunneled CVC placement were included in the study. Data was collected on CLABSI, line days, and serious adverse events in the year prior to and following policy implementation on 9/01/08. RESULTS: A total of 813 supervised central lines were self-reported by residents in four departments. Statistical analysis was performed using paired Wilcoxon signed rank tests. There were reductions in median CLABSI rate (3.52 vs. 2.26; p = 0.015), number of CLBSI per month (16.0 to 10.0; p = 0.012), and line days (4495 vs. 4193; p = 0.019). No serious adverse events reported to the Pennsylvania Patient Safety Authority. CONCLUSIONS: Implementation of a new CVC resident oversight and credentialing policy has been significantly associated with an institution-wide reduction in the rate of CLABSI per 1,000 central line days and total central line days. No serious adverse events were reported. Similar resident oversight policies may benefit other teaching institutions, and support concurrent organizational efforts to reduce hospital acquired infections.
RESUMO
Heterotrimeric G proteins transduce signals from activated transmembrane G protein-coupled receptors to appropriate downstream effectors within cells. Signaling specificity is achieved in part by the specific alpha, beta, and gamma subunits that compose a given heterotrimer. Additional structural and functional diversity in these subunits is generated at the level of posttranslational modification, offering alternate regulatory mechanisms for G protein signaling. Presented here is the identification of a variant of the gamma(2) subunit of G protein heterotrimer purified from bovine brain and the demonstration that this RDTASIA gamma(2) variant, containing unique amino acid sequence at its N terminus, is a substrate for ubiquitylation and degradation via the N-end rule pathway. Although N-end-dependent degradation has been shown to have important functions in peptide import, chromosome segregation, angiogenesis, and cardiovascular development, the identification of cellular substrates in mammalian systems has remained elusive. The isolation of RDTASIA gamma(2) from a native tissue represents identification of a mammalian N-end rule substrate from a physiological source, and elucidates a mechanism for the targeting of G protein gamma subunits for ubiquitylation and degradation.