Insights into the genetic histories and lifeways of Machu Picchu's occupants.

Machu Picchu originally functioned as a palace within the estate of the Inca emperor Pachacuti between ~1420 and 1532 CE. Before this study, little was known about the people who lived and died there, where they came from or how they were related to the inhabitants of the Inca capital of Cusco. We generated genome-wide data for 34 individuals buried at Machu Picchu who are believed to have been retainers or attendants assigned to serve the Inca royal family, as well as 34 individuals from Cusco for comparative purposes. When the ancient DNA results are contextualized using historical and archaeological data, we conclude that the retainer population at Machu Picchu was highly heterogeneous with individuals exhibiting genetic ancestries associated with groups from throughout the Inca Empire and Amazonia. The results suggest a diverse retainer community at Machu Picchu in which people of different genetic backgrounds lived, reproduced, and were interred together.

Association of an Emergency Critical Care Program With Survival and Early Downgrade Among Critically Ill Medical Patients in the Emergency Department.

OBJECTIVES: To determine whether implementation of an Emergency Critical Care Program (ECCP) is associated with improved survival and early downgrade of critically ill medical patients in the emergency department (ED). DESIGN: Single-center, retrospective cohort study using ED-visit data between 2015 and 2019. SETTING: Tertiary academic medical center. PATIENTS: Adult medical patients presenting to the ED with a critical care admission order within 12 hours of arrival. INTERVENTIONS: Dedicated bedside critical care for medical ICU patients by an ED-based intensivist following initial resuscitation by the ED team. MEASUREMENTS AND MAIN RESULTS: Primary outcomes were inhospital mortality and the proportion of patients downgraded to non-ICU status while in the ED within 6 hours of the critical care admission order (ED downgrade <6 hr). A difference-in-differences (DiD) analysis compared the change in outcomes for patients arriving during ECCP hours (2 pm to midnight, weekdays) between the preintervention period (2015-2017) and the intervention period (2017-2019) to the change in outcomes for patients arriving during non-ECCP hours (all other hours). Adjustment for severity of illness was performed using the emergency critical care Sequential Organ Failure Assessment (eccSOFA) score. The primary cohort included 2,250 patients. The DiDs for the eccSOFA-adjusted inhospital mortality decreased by 6.0% (95% CI, -11.9 to -0.1) with largest difference in the intermediate illness severity group (DiD, -12.2%; 95% CI, -23.1 to -1.3). The increase in ED downgrade less than 6 hours was not statistically significant (DiD, 4.8%; 95% CI, -0.7 to 10.3%) except in the intermediate group (DiD, 8.8%; 95% CI, 0.2-17.4). CONCLUSIONS: The implementation of a novel ECCP was associated with a significant decrease in inhospital mortality among critically ill medical ED patients, with the greatest decrease observed in patients with intermediate severity of illness. Early ED downgrades also increased, but the difference was statistically significant only in the intermediate illness severity group.

Selection bias in estimating the relationship between prolonged ED boarding and mortality in emergency critical care patients.

OBJECTIVES: Studies have found that prolonged boarding time for intensive care unit (ICU) patients in the emergency department (ED) is associated with higher in-hospital mortality. However, these studies introduced selection bias by excluding patients with ICU admission orders who were downgraded and never arrived in the ICU. Consequently, they may overestimate mortality in prolonged ED boarders. METHODS: This was a retrospective cohort study at a single center covering the period from August 14, 2015 to August 13, 2019. Adult ED patients with medical ICU admission orders and at least 6 hours of subsequent critical care in either the ED or the ICU were included. Patients were classified as having either prolonged (>6 hours) or non-prolonged (≤6 hours) ED boarding. Downgraded patients were identified, and mortality was compared, both including and excluding downgraded patients. RESULTS: Of 1862 patients, 612 (32.9%) had prolonged boarding; at 6 hours after ICU admission order entry, they were still in the ED. The remaining 1250 (67.1%) had non-prolonged boarding; at 6 hours after the ICU admission order entry, they were already in the ICU. In-hospital mortality in the non-prolonged boarding group was 18.9%. In the prolonged boarding group, 296 (48.4%) patients were downgraded in the ED and never arrived in the ICU. Including these ED downgrades, the mortality in the prolonged boarding group was 13.4% (risk difference -5.5%, 95% confidence interval [CI] -8.9% to -2.0%, P = 0.0031). When we excluded downgrades, the mortality in the prolonged boarding group increased to 17.4% (risk difference -1.5%, 95% CI -6.2% to 3.2%, P = 0.5720). The lower mortality in the prolonged group was attributable to lower severity of illness (mean emergency critical care SOFA [eccSOFA] difference: -0.8, 95% CI -1.1 to -0.4, P < 0.0001). CONCLUSIONS: Excluding critical care patients who were downgraded in the ED leads to selection bias and overestimation of mortality among prolonged ED boarders.

Kinetic and Structural Characterization of Sialidases (Kdnases) from Ascomycete Fungal Pathogens.

Sialidases catalyze the release of sialic acid from the terminus of glycan chains. We previously characterized the sialidase from the opportunistic fungal pathogen, Aspergillus fumigatus, and showed that it is a Kdnase. That is, this enzyme prefers 3-deoxy-d-glycero-d-galacto-non-2-ulosonates (Kdn glycosides) as the substrate compared to N-acetylneuraminides (Neu5Ac). Here, we report characterization and crystal structures of putative sialidases from two other ascomycete fungal pathogens, Aspergillus terreus (AtS) and Trichophyton rubrum (TrS). Unlike A. fumigatus Kdnase (AfS), hydrolysis with the Neu5Ac substrates was negligible for TrS and AtS; thus, TrS and AtS are selective Kdnases. The second-order rate constant for hydrolysis of aryl Kdn glycosides by AtS is similar to that by AfS but 30-fold higher by TrS. The structures of these glycoside hydrolase family 33 (GH33) enzymes in complex with a range of ligands for both AtS and TrS show subtle changes in ring conformation that mimic the Michaelis complex, transition state, and covalent intermediate formed during catalysis. In addition, they can aid identification of important residues for distinguishing between Kdn and Neu5Ac substrates. When A. fumigatus, A. terreus, and T. rubrum were grown in chemically defined media, Kdn was detected in mycelial extracts, but Neu5Ac was only observed in A. terreus or T. rubrum extracts. The C8 monosaccharide 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) was also identified in A. fumigatus and T. rubrum samples. A fluorescent Kdn probe was synthesized and revealed the localization of AfS in vesicles at the cell surface.

A strontium isoscape for the Conchucos region of highland Peru and its application to Andean archaeology.

Strontium isotope (87Sr/86Sr) analysis of human skeletal remains is an important method in archaeology to examine past human mobility and landscape use. 87Sr/86Sr signatures of a given location are largely determined by the underlying bedrock, and these geology specific isotope signatures are incorporated into skeletal tissue through food and water, often permitting the differentiation of local and non-local individuals in past human populations. This study presents the results of a systematic survey of modern flora and fauna (n = 100) from 14 locations to map the bioavailable 87Sr/86Sr signatures of the Conchucos region, an area where the extent of geologic variability was previously unknown. We illustrate the necessity to examine the variation in 87Sr/86Sr values of the different geological formations available to human land use to document the range of possible local 87Sr/86Sr values. Within the Conchucos region we found significant variation in environmental 87Sr/86Sr values (0.7078-0.7214). The resulting isoscape represents the largest regionally specific bioavailable 87Sr/86Sr map (3,840 km2) to date for the Andes, and will serve as a baseline for future archaeological studies of human mobility in this part of the Peruvian highlands.

eccSOFA: SOFA illness severity score adapted to predict in-hospital mortality in emergency critical care patients.

BACKGROUND: Boarding of ICU patients in the ED is increasing. Illness severity scores may help emergency physicians stratify risk to guide earlier transfer to the ICU and assess pre-ICU interventions by adjusting for baseline mortality risk. Most existing illness severity scores are based on data that is not available at the time of the hospital admission decision or cannot be extracted from the electronic health record (EHR). We adapted the SOFA score to create a new illness severity score (eccSOFA) that can be calculated at the time of ICU admission order entry in the ED using EHR data. We evaluated this score in a cohort of emergency critical care (ECC) patients at a single academic center over a period of 3 years. METHODS: This was a retrospective cohort study using EHR data to assess predictive accuracy of eccSOFA for estimating in-hospital mortality risk. The patient population included all adult patients who had a critical care admission order entered while in the ED of an academic medical center between 10/24/2013 and 9/30/2016. eccSOFA's discriminatory ability for in-hospital mortality was assessed using ROC curves. RESULTS: Of the 3912 patients whose in-hospital mortality risk was estimated, 2260 (57.8%) were in the low-risk group (scores 0-3), 1203 (30.8%) in the intermediate-risk group (scores 4-7), and 449 (11.5%) in the high-risk group (scores 8+). In-hospital mortality for the low-, intermediate, and high-risk groups was 4.2% (95%CI: 3.4-5.1), 15.5% (95% CI 13.5-17.6), and 37.9% (95% CI 33.4-42.3) respectively. The AUROC was 0.78 (95%CI: 0.75-0.80) for the integer score and 0.75 (95% CI: 0.72-0.77) for the categorical eccSOFA. CONCLUSIONS: As a predictor of in-hospital mortality, eccSOFA can be calculated based on variables that are commonly available at the time of critical care admission order entry in the ED and has discriminatory ability that is comparable to other commonly used illness severity scores. Future studies should assess the calibration of our absolute risk predictions.

Effect of emergency critical care nurses and emergency department boarding time on in-hospital mortality in critically ill patients.

STUDY HYPOTHESIS: We hypothesized that establishing a program of specialized emergency critical care (ECC) nurses in the ED would improve mortality of ICU patients boarding in the ED. METHODS: This was a retrospective before-after cohort study using electronic health record data at an academic medical center. We compared in-hospital mortality between the pre- and post-intervention periods and between non-prolonged (≤6 h) boarding time and prolonged (>6 h) boarding time. In-hospital mortality was stratified by illness severity (eccSOFA category) and adjusted using logistic regression. RESULTS: Severity-adjusted in-hospital mortality decreased from 12.8% pre-intervention to 12.3% post-intervention (-0.5% (95% CI, -3.1% to 2.1%), which was not statistically significant. This was despite a concurrent increase in ED and hospital crowding. The proportion of ECC patients downgraded to a lower level of care while still in the ED increased from 6.4% in the pre-intervention period to 17.0% in the post-intervention period. (+10.6%, 8.2% to 13.0%, p < 0.001). Severity-adjusted mortality was 12.8% in the non-prolonged group vs. 11.3% in the prolonged group (p = 0.331). CONCLUSIONS: During the post-intervention period, there was a significant increase in illness severity, hospital congestion, ED boarding time, and downgrades in the ED, but no significant change in mortality. These findings suggest that ECC nurses may improve the safety of boarding ICU patients in the ED. Longer ED boarding times were not associated with higher mortality in either the pre- or post-intervention periods.

The Aspergillus fumigatus Sialidase (Kdnase) Contributes to Cell Wall Integrity and Virulence in Amphotericin B-Treated Mice.

Aspergillus fumigatus is a filamentous fungus that can cause a life-threatening invasive pulmonary aspergillosis (IPA) in immunocompromised individuals. We previously characterized an exo-sialidase from A. fumigatus that prefers the sialic acid substrate, 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (Kdn); hence it is a Kdnase. Sialidases are known virulence factors in other pathogens; therefore, the goal of our study was to evaluate the importance of Kdnase in A. fumigatus. A kdnase knockout strain (Δkdnase) was unable to grow on medium containing Kdn and displayed reduced growth and abnormal morphology. Δkdnase was more sensitive than wild type to hyperosmotic conditions and the antifungal agent, amphotericin B. In contrast, Δkdnase had increased resistance to nikkomycin, Congo Red and Calcofluor White indicating activation of compensatory cell wall chitin deposition. Increased cell wall thickness and chitin content in Δkdnase were confirmed by electron and immunofluorescence microscopy. In a neutropenic mouse model of invasive aspergillosis, the Δkdnase strain had attenuated virulence and a significantly lower lung fungal burden but only in animals that received liposomal amphotericin B after spore exposure. Macrophage numbers were almost twofold higher in lung sections from mice that received the Δkdnase strain, possibly related to higher survival of macrophages that internalized the Δkdnase conidia. Thus, A. fumigatus Kdnase is important for fungal cell wall integrity and virulence, and because Kdnase is not present in the host, it may represent a potential target for the development of novel antifungal agents.

Journal clubs: a two-site case study of nurses' continuing professional development.

OBJECTIVE: The purpose of this study was to explore the experience of intensive care unit nurses in two nursing journal clubs. BACKGROUND: Few nurses feel comfortable using evidence to guide their practice. Communities of nurses are beginning to be understood as essential for the production and transfer of knowledge. Journal clubs are a meeting among colleagues to discuss professional literature. However, there is little nursing journal club research. SETTINGS AND PARTICIPANTS: Over six months, 70 healthcare professionals (including 64 nurses) participated in monthly journal club meetings in two ICUs of one Ontario hospital. METHODS: A qualitative two-site case study methodology with six data collection methods was employed including individual interviews, focus groups, surveys, document analysis, and field notes. FINDINGS: Journal clubs provided nurses with incentive and confidence to read research articles, created a community of practice, provided a structure to reflect-on-practice, and led to reported changes in clinical practice. However, any gains in competence of nurses with research critical appraisal skills were probably modest. CONCLUSION: Journal clubs can foster modest knowledge translation and evidence-based practice at a grass roots level. However, journal clubs may have a greater impact when implemented alongside other knowledge translation strategies such as working with graduate prepared nurses.

Structural requirements for the activity of the MirB ferrisiderophore transporter of Aspergillus fumigatus.

Siderophores have been identified as virulence factors in the opportunistic fungal pathogen Aspergillus fumigatus. The 14-pass transmembrane protein MirB is postulated to function as a siderophore transporter, responsible for uptake of the hydroxamate siderophore N,N',N″-triacetylfusarinine C (TAFC). Our aim was to identify amino acids of A. fumigatus MirB that are crucial for uptake of TAFC. Site-directed mutagenesis was used to create MirB mutants. Expression of wild-type and mutant proteins in the Saccharomyces cerevisiae strain PHY14, which lacks endogenous siderophore transporters, was confirmed by Western blotting. TAFC transport assays using (55)Fe-labeled TAFC and growth assays with Fe-TAFC as the sole iron source identified alanine 125, tyrosine 577, loop 3, and the second half of loop 7 (Loop7Del2) as crucial for function, since their substitution or deletion abrogated uptake completely. Wild-type MirB transported ferricrocin and coprogen as well as TAFC but not ferrichrysin. MirB was localized by fluorescence microscopy using antisera raised against a MirB extracellular loop peptide. Immunofluorescence microscopy showed that in yeast, wild-type MirB had a punctate distribution under the plasma membrane, as did the A125D and Y577A strains, indicating that the defect in transport of these mutants was unlikely to be due to mislocalization or degradation. MirB immunolocalization in A. fumigatus showed that the transporter was found in vesicles which cycled between the cytoplasm and the plasma membrane and was concentrated at the hyphal tips. The location of MirB was not influenced by the presence of the siderophore TAFC but was sensitive to internal iron stores.