Structural Basis for Cholesterol Transport-like Activity of the Hedgehog Receptor Patched.

Hedgehog protein signals mediate tissue patterning and maintenance by binding to and inactivating their common receptor Patched, a 12-transmembrane protein that otherwise would suppress the activity of the 7-transmembrane protein Smoothened. Loss of Patched function, the most common cause of basal cell carcinoma, permits unregulated activation of Smoothened and of the Hedgehog pathway. A cryo-EM structure of the Patched protein reveals striking transmembrane domain similarities to prokaryotic RND transporters. A central hydrophobic conduit with cholesterol-like contents courses through the extracellular domain and resembles that used by other RND proteins to transport substrates, suggesting Patched activity in cholesterol transport. Cholesterol activity in the inner leaflet of the plasma membrane is reduced by PTCH1 expression but rapidly restored by Hedgehog stimulation, suggesting that PTCH1 regulates Smoothened by controlling cholesterol availability.

Three years of COVID-19 and life satisfaction in Europe: A macro view.

Every country in Europe experienced an adverse impact from the COVID-19 pandemic on life satisfaction, though on average, satisfaction with life in the summer of 2022 is about the same as the pre-pandemic value in the autumn of 2019. Typically, an upsurge in the severity of the pandemic (measured by the number of COVID-related deaths) is associated with declining life satisfaction and an ebbing, with increasing life satisfaction. Of the three waves of the pandemic between March 2020 and the autumn of 2022, the most severe impact typically occurred in 2021 during the second wave; in the third wave, the response declined due to the spread of effective vaccines and the takeover of omicron variants.

Biochemical and structural characterization of a sphingomonad diarylpropane lyase for cofactorless deformylation.

Lignin valorization is being intensely pursued via tandem catalytic depolymerization and biological funneling to produce single products. In many lignin depolymerization processes, aromatic dimers and oligomers linked by carbon-carbon bonds remain intact, necessitating the development of enzymes capable of cleaving these compounds to monomers. Recently, the catabolism of erythro-1,2-diguaiacylpropane-1,3-diol (erythro-DGPD), a ring-opened lignin-derived ß-1 dimer, was reported in Novosphingobium aromaticivorans. The first enzyme in this pathway, LdpA (formerly LsdE), is a member of the nuclear transport factor 2 (NTF-2)-like structural superfamily that converts erythro-DGPD to lignostilbene through a heretofore unknown mechanism. In this study, we performed biochemical, structural, and mechanistic characterization of the N. aromaticivorans LdpA and another homolog identified in Sphingobium sp. SYK-6, for which activity was confirmed in vivo. For both enzymes, we first demonstrated that formaldehyde is the C1 reaction product, and we further demonstrated that both enantiomers of erythro-DGPD were transformed simultaneously, suggesting that LdpA, while diastereomerically specific, lacks enantioselectivity. We also show that LdpA is subject to a severe competitive product inhibition by lignostilbene. Three-dimensional structures of LdpA were determined using X-ray crystallography, including substrate-bound complexes, revealing several residues that were shown to be catalytically essential. We used density functional theory to validate a proposed mechanism that proceeds via dehydroxylation and formation of a quinone methide intermediate that serves as an electron sink for the ensuing deformylation. Overall, this study expands the range of chemistry catalyzed by the NTF-2-like protein family to a prevalent lignin dimer through a cofactorless deformylation reaction.

Smoothened stimulation by membrane sterols drives Hedgehog pathway activity.

Hedgehog signalling is fundamental to embryonic development and postnatal tissue regeneration1. Aberrant postnatal Hedgehog signalling leads to several malignancies, including basal cell carcinoma and paediatric medulloblastoma2. Hedgehog proteins bind to and inhibit the transmembrane cholesterol transporter Patched-1 (PTCH1), which permits activation of the seven-transmembrane transducer Smoothened (SMO) via a mechanism that is poorly understood. Here we report the crystal structure of active mouse SMO bound to both the agonist SAG21k and to an intracellular binding nanobody that stabilizes a physiologically relevant active state. Analogous to other G protein-coupled receptors, the activation of SMO is associated with subtle motions in the extracellular domain, and larger intracellular changes. In contrast to recent models3-5, a cholesterol molecule that is critical for SMO activation is bound deep within the seven-transmembrane pocket. We propose that the inactivation of PTCH1 by Hedgehog allows a transmembrane sterol to access this seven-transmembrane site (potentially through a hydrophobic tunnel), which drives the activation of SMO. These results-combined with signalling studies and molecular dynamics simulations-delineate the structural basis for PTCH1-SMO regulation, and suggest a strategy for overcoming clinical resistance to SMO inhibitors.

Explaining happiness trends in Europe.

In Europe, differences among countries in the overall change in happiness since the early 1980s have been due chiefly to the generosity of welfare state programs-increasing happiness going with increasing generosity and declining happiness with declining generosity. This is the principal conclusion from a time-series study of 10 Northern, Western, and Southern European countries with the requisite data. In the present study, cross-section analysis of recent data gives a misleading impression that economic growth, social capital, and/or quality of the environment are driving happiness trends, but in the long-term, time-series data, these variables have no relation to happiness.

A novel terpene synthase controls differences in anti-aphrodisiac pheromone production between closely related Heliconius butterflies.

Plants and insects often use the same compounds for chemical communication, but not much is known about the genetics of convergent evolution of chemical signals. The terpene (E)-ß-ocimene is a common component of floral scent and is also used by the butterfly Heliconius melpomene as an anti-aphrodisiac pheromone. While the biosynthesis of terpenes has been described in plants and microorganisms, few terpene synthases (TPSs) have been identified in insects. Here, we study the recent divergence of 2 species, H. melpomene and Heliconius cydno, which differ in the presence of (E)-ß-ocimene; combining linkage mapping, gene expression, and functional analyses, we identify 2 novel TPSs. Furthermore, we demonstrate that one, HmelOS, is able to synthesise (E)-ß-ocimene in vitro. We find no evidence for TPS activity in HcydOS (HmelOS ortholog of H. cydno), suggesting that the loss of (E)-ß-ocimene in this species is the result of coding, not regulatory, differences. The TPS enzymes we discovered are unrelated to previously described plant and insect TPSs, demonstrating that chemical convergence has independent evolutionary origins.

Using Inundation Extents to Predict Microbial Contamination in Private Wells after Flooding Events.

Disaster recovery poses unique challenges for residents reliant on private wells. Flooding events are drivers of microbial contamination in well water, but the relationship observed between flooding and contamination varies substantially. Here, we investigate the performance of different flood boundaries─the FEMA 100 year flood hazard boundary, height above nearest drainage-derived inundation extents, and satellite-derived extents from the Dartmouth Flood Observatory─in their ability to identify well water contamination following Hurricane Florence. Using these flood boundaries, we estimated about 2600 wells to 108,400 private wells may have been inundated─over 2 orders of magnitude difference based on boundary used. Using state-generated routine and post-Florence testing data, we observed that microbial contamination rates were 7.1-10.5 times higher within the three flood boundaries compared to routine conditions. However, the ability of the flood boundaries to identify contaminated samples varied spatially depending on the type of flooding (e.g., riverine, overbank, coastal). While participation in testing increased after Florence, rates were overall still low. With <1% of wells tested, there is a critical need for enhanced well water testing efforts. This work provides an understanding of the strengths and limitations of inundation mapping techniques, which are critical for guiding postdisaster well water response and recovery.

A Comparison of Telencephalon Composition among Chickens, Junglefowl, and Wild Galliforms.

INTRODUCTION: Domestication is the process of modifying animals for human benefit through selective breeding in captivity. One of the traits that often diverges is the size of the brain and its constituent regions; almost all domesticated species have relatively smaller brains and brain regions than their wild ancestors. Although the effects of domestication on the brain have been investigated across a range of both mammal and bird species, almost nothing is known about the neuroanatomical effects of domestication on the world's most common bird: the chicken (Gallus gallus). METHODS: We compared the quantitative neuroanatomy of the telencephalon of white leghorn chickens with red junglefowl, their wild counterpart, and several wild galliform species. We focused specifically on the telencephalon because telencephalic regions typically exhibit the biggest differences in size in domesticate-wild comparisons. RESULTS: Relative telencephalon size was larger in chickens than in junglefowl and ruffed grouse (Bonasa umbellus). The relative size of telencephalic regions did not differ between chickens and junglefowl, but did differ in comparison with ruffed grouse. Ruffed grouse had larger hyperpallia and smaller entopallial, nidopallial, and striatal volumes than chickens and junglefowl. Multivariate analyses that included an additional three wild grouse species corroborated these findings: chicken and junglefowl have relatively larger nidopallial and striatal volumes than grouse. Conversely, the mesopallial and hyperpallial volumes tended to be relatively smaller in chickens and junglefowl. CONCLUSION: From this suite of comparisons, we conclude that chickens do not follow a pattern of widespread decreases in telencephalic region sizes that is often viewed as typical of domestication. Instead, chickens have undergone a mosaic of changes with some regions increasing and others decreasing in size, and there are few differences between chickens and junglefowl.

Psychological interventions for asthma in children and adolescents.

BACKGROUND: Rates of asthma are high in children and adolescents, and young people with asthma generally report poorer health outcomes than those without asthma. Young people with asthma experience a range of challenges that may contribute to psychological distress. This is compounded by the social, psychological, and developmental challenges experienced by all people during this life stage. Psychological interventions (such as behavioural therapies or cognitive therapies) have the potential to reduce psychological distress and thus improve behavioural outcomes such as self-efficacy and medication adherence. In turn, this may reduce medical contacts and asthma attacks. OBJECTIVES: To determine the efficacy of psychological interventions for modifying health and behavioural outcomes in children with asthma, compared with usual treatment, treatment with no psychological component, or no treatment. SEARCH METHODS: We searched the Cochrane Airways Group Specialised Register (including CENTRAL, CRS, MEDLINE, Embase, PsycINFO, CINAHL EBSCO, AMED EBSCO), proceedings of major respiratory conferences, reference lists of included studies, and online clinical databases. The most recent search was conducted on 22 August 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing psychological interventions of any duration with usual care, active controls, or a waiting-list control in male and female children and adolescents (aged five to 18 years) with asthma. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. symptoms of anxiety and depression, 2. medical contacts, and 3. asthma attacks. Our secondary outcomes were 1. self-reported asthma symptoms, 2. medication use, 3. quality of life, and 4. adverse events/side effects. MAIN RESULTS: We included 24 studies (1639 participants) published between 1978 and 2021. Eleven studies were set in the USA, five in China, two in Sweden, three in Iran, and one each in the Netherlands, UK, and Germany. Participants' asthma severity ranged from mild to severe. Three studies included primary school-aged participants (five to 12 years), two included secondary school-aged participants (13 to 18 years), and 18 included both age groups, while one study was unclear on the age ranges. Durations of interventions ranged from three days to eight months. One intervention was conducted online and the rest were face-to-face. Meta-analysis was not possible due to clinical heterogeneity (interventions, populations, outcome tools and definitions, and length of follow-up). We tabulated and summarised the results narratively with reference to direction, magnitude, and certainty of effects. The certainty of the evidence was very low for all outcomes. A lack of information about scale metrics and minimal clinically important differences for the scales used to measure anxiety, depression, asthma symptoms, medication use, and quality of life made it difficult to judge clinical significance. Primary outcomes Four studies (327 participants) reported beneficial or mixed effects of psychological interventions versus controls for symptoms of anxiety, and one found little to no difference between groups (104 participants). Two studies (166 participants) that evaluated symptoms of depression both reported benefits of psychological interventions compared to controls. Three small studies (92 participants) reported a reduction in medical contacts, but two larger studies (544 participants) found little or no difference between groups in this outcome. Two studies (107 participants) found that the intervention had an important beneficial effect on number of asthma attacks, and one small study (22 participants) found little or no effect of the intervention for this outcome. Secondary outcomes Eleven studies (720 participants) assessed asthma symptoms; four (322 participants) reported beneficial effects of the intervention compared to control, five (257 participants) reported mixed or unclear findings, and two (131 participants) found little or no difference between groups. Eight studies (822 participants) reported a variety of medication use measures; six of these studies (670 participants) found a positive effect of the intervention versus control, and the other two (152 participants) found little or no difference between the groups. Across six studies (653 participants) reporting measures of quality of life, the largest three (522 participants) found little or no difference between the groups. Where findings were positive or mixed, there was evidence of selective reporting (2 studies, 131 participants). No studies provided data related to adverse effects. AUTHORS' CONCLUSIONS: Most studies that reported symptoms of anxiety, depression, asthma attacks, asthma symptoms, and medication use found a positive effect of psychological interventions versus control on at least one measure. However, some findings were mixed, it was difficult to judge clinical significance, and the evidence for all outcomes is very uncertain due to clinical heterogeneity, small sample sizes, incomplete reporting, and risk of bias. There is limited evidence to suggest that psychological interventions can reduce the need for medical contact or improve quality of life, and no studies reported adverse events. It was not possible to identify components of effective interventions and distinguish these from interventions showing no evidence of an effect due to substantial heterogeneity. Future investigations of evidence-based psychological techniques should consider standardising outcomes to support cross-comparison and better inform patient and policymaker decision-making.

Does Anesthesiologist Experience Influence Early Postoperative Outcomes Following Orthognathic Surgery?

BACKGROUND: Anesthesia provider experience impacts nausea and vomiting in other surgical specialties but its influence within orthognathic surgery remains unclear. PURPOSE: The study purpose was to evaluate whether anesthesiologist experience with orthognathic surgery impacts postoperative outcomes, including nausea, emesis, narcotic use, and perioperative adverse events, for patients undergoing orthognathic surgery. STUDY DESIGN, SETTING, SAMPLE: This is a retrospective cohort study of subjects aged 12 to 35 years old who underwent orthognathic surgery, including Le Fort 1 osteotomy ± bilateral sagittal split osteotomy, at Boston Children's Hospital from August 2018 to January 2022. Subjects were excluded if they had incomplete medical records, a syndromic diagnosis, or a hospital stay of greater than 2 days. PREDICTOR VARIABLE: The predictor variable was attending anesthesia provider experience with orthognathic surgery. Providers were classified as experienced or inexperienced, with experienced providers defined as having anesthetized ≥10 orthognathic operations during the study period. MAIN OUTCOME VARIABLES: The primary outcome variable was postoperative nausea. Secondary outcome variables were emesis, narcotic use in the hospital, and perioperative adverse events within 30 days of their operation. COVARIATES: Study covariates included age, sex, race, comorbidities (body mass index, history of psychiatric illness, cleft lip and/or palate, chronic pain, postoperative nausea/vomiting, gastrointestinal conditions), enhanced recovery after surgery protocol enrollment, and intraoperative factors (operation performed, anesthesia/procedure times, estimated blood loss, intravenous fluid and narcotic administration, and anesthesiologist's years in practice). ANALYSES: χ2 and unpaired t-tests were used to compare primary predictor and covariates against outcome variables. A P-value <.05 was considered significant. RESULTS: There were 118 subjects included in the study after 4 were excluded (51.7% female, mean age 19.1 ± 3.30 years). There were 71 operations performed by 5 experienced anesthesiologists (mean cases/provider 15.4 ± 5.95) and 47 cases by 22 different inexperienced providers (mean cases/provider 1.91 ± 1.16). The nausea rate was 52.1% for experienced providers and 53.2% for inexperienced providers (P = .909). There were no statistically significant associations between anesthesiologist experience and any outcome variable (P > .341). CONCLUSIONS AND RELEVANCE: Anesthesia providers' experience with orthognathic surgery did not significantly influence postoperative nausea, emesis, narcotic use, or perioperative adverse events.

Intracellular pathways for lignin catabolism in white-rot fungi.

Lignin is a biopolymer found in plant cell walls that accounts for 30% of the organic carbon in the biosphere. White-rot fungi (WRF) are considered the most efficient organisms at degrading lignin in nature. While lignin depolymerization by WRF has been extensively studied, the possibility that WRF are able to utilize lignin as a carbon source is still a matter of controversy. Here, we employ 13C-isotope labeling, systems biology approaches, and in vitro enzyme assays to demonstrate that two WRF, Trametes versicolor and Gelatoporia subvermispora, funnel carbon from lignin-derived aromatic compounds into central carbon metabolism via intracellular catabolic pathways. These results provide insights into global carbon cycling in soil ecosystems and furthermore establish a foundation for employing WRF in simultaneous lignin depolymerization and bioconversion to bioproducts-a key step toward enabling a sustainable bioeconomy.

An Enhanced Recovery After Surgery (ERAS) Protocol for Orthognathic Surgery Reduces Rates of Postoperative Nausea.

For many surgical procedures, enhanced recovery after surgery (ERAS) protocols have improved patient outcomes, particularly postoperative nausea and vomiting. The purpose of this study was to evaluate postoperative nausea following orthognathic surgery after the implementation of an ERAS protocol. This retrospective cohort study included patients between 12 and 35 years old who underwent orthognathic surgery at Boston Children's Hospital from April 2018 to December 2022. Patients with syndromes or a hospital stay greater than 48 hours were excluded from the study. The primary predictor was enrollment in our institutional ERAS protocol. The main outcome variable was postoperative nausea. Intraoperative and postoperative covariates were compared between groups using unpaired t tests and chi squared analysis. Univariate and multivariate regression models with 95% confidence intervals were performed to identify predictors for nausea. A P value<0.05 was considered significant. There were 128 patients (68 non-ERAS, 60 ERAS) included in this study (51.6% female, mean age 19.02±3.25 years). The ERAS group received less intraoperative fluid (937.0±462.3 versus 1583.6±847.6 mL, P ≤0.001) and experienced less postoperative nausea (38.3% versus 63.2%, P =0.005). Enhanced recovery after surgery status ( P =0.005) was a predictor for less postoperative nausea, whereas bilateral sagittal split osteotomy ( P =0.045) and length of stay ( P =0.007) were positive predictors for postoperative nausea in multivariate logistic regression analysis. Implementing an ERAS protocol for orthognathic surgery reduces postoperative nausea. Level of Evidence: Level III-therapeutic.

Comparing Outcomes of Acute Versus Gradual Surgical Correction in Brachymetatarsia.

Brachymetatarsia consists of a shortened metatarsal resulting in a shorter toe. Pain with shoe wear and cosmetic concerns are the main reasons for surgical intervention. Surgical techniques to increase metatarsal length include acute lengthening with interpositional bone grafting or gradual lengthening with callus distraction. We performed a retrospective cohort study for 1 surgeon's patients at 1 institution over 10 years. Twenty-nine feet in 22 patients met inclusion criteria for acute correction; 16 feet in 11 patients were included for gradual correction. Mean ages were 26.3 ± 12.1 and 27 ± 10.8 in the acute and gradual groups, respectively (p = .79). Most patients were female: 95.4% of acute cases and 90.1% of gradual cases. Most involved lengthening the fourth metatarsal: 86.7% and 100% of acute and gradual groups, respectively (p = .54). Correction obtained amounted to 14.4 ± 2.97 mm (range, 10-22 mm) in acute cases and 14.8 ± 2.39 mm (range, 10-20 mm) in gradual cases (p = .81). The mean percent increase in metatarsal length was 21.1 ± 14% for acute and 22.6 ± 12.4% for gradual (p = .72). Mean consolidation was 8.9 ± 2.51 weeks for acute and 21.4 ± 10.8 weeks for gradual (p = <.001). Nonunions were most common in the gradual group (37.5%) with need for more revisional surgery (43.5%) compared with the acute group; both were statistically significant. We conclude that acute brachymetatarsia correction can obtain correction similar to the gradual technique with fewer postoperative complications and less osseous consolidation time.

Using Free-Breathing MRI to Quantify Pancreatic Fat and Investigate Spatial Heterogeneity in Children.

BACKGROUND: MRI acquisition for pediatric pancreatic fat quantification is limited by breath-holds (BH). Full segmentation (FS) or small region of interest (ROI) analysis methods may not account for pancreatic fat spatial heterogeneity, which may limit accuracy. PURPOSE: To improve MRI acquisition and analysis for quantifying pancreatic proton-density fat fraction (pPDFF) in children by investigating free-breathing (FB)-MRI, characterizing pPDFF spatial heterogeneity, and relating pPDFF to clinical markers. STUDY TYPE: Prospective. POPULATION: A total of 34 children, including healthy (N = 16, 8 female) and overweight (N = 18, 5 female) subjects. FIELD STRENGTH AND SEQUENCES: 3 T; multiecho gradient-echo three-dimensional (3D) stack-of-stars FB-MRI, multiecho gradient-echo 3D Cartesian BH-MRI. ASSESSMENT: A radiologist measured FS- and ROI-based pPDFF on FB-MRI and BH-MRI PDFF maps, with anatomical images as references. Regional pPDFF in the pancreatic head, body, and tail were measured on FB-MRI. FS-pPDFF, ROI-pPDFF, and regional pPDFF were compared, and related to clinical markers, including hemoglobin A1c. STATISTICAL TESTS: T-test, Bland-Altman analysis, Lin's concordance correlation coefficient (CCC), one-way analysis of variance, and Spearman's rank correlation coefficient were used. P < 0.05 was considered significant. RESULTS: FS-pPDFF and ROI-pPDFF from FB-MRI and BH-MRI had mean difference = 0.4%; CCC was 0.95 for FS-pPDFF and 0.62 for ROI-pPDFF. FS-pPDFF was higher than ROI-pPDFF (10.4% ± 6.4% vs. 4.2% ± 2.8%). Tail-pPDFF (11.6% ± 8.1%) was higher than body-pPDFF (8.9% ± 6.3%) and head-pPDFF (8.7% ± 5.2%). Head-pPDFF and body-pPDFF positively correlated with hemoglobin A1c. DATA CONCLUSION: FB-MRI pPDFF is comparable to BH-MRI. Spatial heterogeneity affects pPDFF quantification. Regional measurements of pPDFF in the head and body were correlated with hemoglobin A1c, a marker of insulin sensitivity. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

The role of body size and cuticular hydrocarbons in the desiccation resistance of invasive Argentine ants (Linepithema humile).

An insect's cuticle is typically covered in a layer of wax prominently featuring various hydrocarbons involved in desiccation resistance and chemical communication. In Argentine ants (Linepithema humile), cuticular hydrocarbons (CHCs) communicate colony identity, but also provide waterproofing necessary to survive dry conditions. Theory suggests different CHC compound classes have functional trade-offs, such that selection for compounds used in communication would compromise waterproofing, and vice versa. We sampled sites of invasive L. humile populations from across California to test whether CHC differences between them can explain differences in their desiccation survival. We hypothesized that CHCs whose abundance was correlated with environmental factors would determine survival during desiccation, but our regression analysis did not support this hypothesis. Interestingly, we found the abundance of most CHCs had a negative correlation with survival, regardless of compound class. We suggest that the CHC differences between L. humile nests in California are insufficient to explain their differential survival against desiccation, and that body mass is a better predictor of desiccation survival at this scale of comparison.

Co-Occurrence and Cooperation between Comammox and Anammox Bacteria in a Full-Scale Attached Growth Municipal Wastewater Treatment Process.

Cooperation between comammox and anammox bacteria for nitrogen removal has been recently reported in laboratory-scale systems, including synthetic community constructs; however, there are no reports of full-scale municipal wastewater treatment systems with such cooperation. Here, we report intrinsic and extant kinetics as well as genome-resolved community characterization of a full-scale integrated fixed film activated sludge (IFAS) system where comammox and anammox bacteria co-occur and appear to drive nitrogen loss. Intrinsic batch kinetic assays indicated that majority of the aerobic ammonia oxidation was driven by comammox bacteria (1.75 ± 0.08 mg-N/g TS-h) in the attached growth phase, with minimal contribution by ammonia-oxidizing bacteria. Interestingly, a portion of total inorganic nitrogen (∼8%) was consistently lost during these aerobic assays. Aerobic nitrite oxidation assays eliminated the possibility of denitrification as a cause of nitrogen loss, while anaerobic ammonia oxidation assays resulted in rates consistent with anammox stoichiometry. Full-scale experiments at different dissolved oxygen (DO = 2 - 6 mg/L) setpoints indicated persistent nitrogen loss that was partly sensitive to DO concentrations. Genome-resolved metagenomics confirmed the high abundance (relative abundance 6.53 ± 0.34%) of two Brocadia-like anammox populations, while comammox bacteria within the Ca. Nitrospira nitrosa cluster were lower in abundance (0.37 ± 0.03%) and Nitrosomonas-like ammonia oxidizers were even lower (0.12 ± 0.02%). Collectively, our study reports for the first time the co-occurrence and cooperation of comammox and anammox bacteria in a full-scale municipal wastewater treatment system.

Gradual Recovery of Building Plumbing-Associated Microbial Communities after Extended Periods of Altered Water Demand during the COVID-19 Pandemic.

COVID-19 pandemic-related building restrictions heightened drinking water microbiological safety concerns post-reopening due to the unprecedented nature of commercial building closures. Starting with phased reopening (i.e., June 2020), we sampled drinking water for 6 months from three commercial buildings with reduced water usage and four occupied residential households. Samples were analyzed using flow cytometry and full-length 16S rRNA gene sequencing along with comprehensive water chemistry characterization. Prolonged building closures resulted in 10-fold higher microbial cell counts in the commercial buildings [(2.95 ± 3.67) × 105 cells mL-1] than in residential households [(1.11 ± 0.58) × 104 cells mL-1] with majority intact cells. While flushing reduced cell counts and increased disinfection residuals, microbial communities in commercial buildings remained distinct from those in residential households on the basis of flow cytometric fingerprinting [Bray-Curtis dissimilarity (dBC) = 0.33 ± 0.07] and 16S rRNA gene sequencing (dBC = 0.72 ± 0.20). An increase in water demand post-reopening resulted in gradual convergence in microbial communities in water samples collected from commercial buildings and residential households. Overall, we find that the gradual recovery of water demand played a key role in the recovery of building plumbing-associated microbial communities as compared to short-term flushing after extended periods of reduced water demand.

Hedgehog pathway activation through nanobody-mediated conformational blockade of the Patched sterol conduit.

Activation of the Hedgehog pathway may have therapeutic value for improved bone healing, taste receptor cell regeneration, and alleviation of colitis or other conditions. Systemic pathway activation, however, may be detrimental, and agents amenable to tissue targeting for therapeutic application have been lacking. We have developed an agonist, a conformation-specific nanobody against the Hedgehog receptor Patched1 (PTCH1). This nanobody potently activates the Hedgehog pathway in vitro and in vivo by stabilizing an alternative conformation of a Patched1 "switch helix," as revealed by our cryogenic electron microscopy structure. Nanobody-binding likely traps Patched in one stage of its transport cycle, thus preventing substrate movement through the Patched1 sterol conduit. Unlike the native Hedgehog ligand, this nanobody does not require lipid modifications for its activity, facilitating mechanistic studies of Hedgehog pathway activation and the engineering of pathway activating agents for therapeutic use. Our conformation-selective nanobody approach may be generally applicable to the study of other PTCH1 homologs.

Outer membrane vesicles catabolize lignin-derived aromatic compounds in Pseudomonas putida KT2440.

Lignin is an abundant and recalcitrant component of plant cell walls. While lignin degradation in nature is typically attributed to fungi, growing evidence suggests that bacteria also catabolize this complex biopolymer. However, the spatiotemporal mechanisms for lignin catabolism remain unclear. Improved understanding of this biological process would aid in our collective knowledge of both carbon cycling and microbial strategies to valorize lignin to value-added compounds. Here, we examine lignin modifications and the exoproteome of three aromatic-catabolic bacteria: Pseudomonas putida KT2440, Rhodoccocus jostii RHA1, and Amycolatopsis sp. ATCC 39116. P. putida cultivation in lignin-rich media is characterized by an abundant exoproteome that is dynamically and selectively packaged into outer membrane vesicles (OMVs). Interestingly, many enzymes known to exhibit activity toward lignin-derived aromatic compounds are enriched in OMVs from early to late stationary phase, corresponding to the shift from bioavailable carbon to oligomeric lignin as a carbon source. In vivo and in vitro experiments demonstrate that enzymes contained in the OMVs are active and catabolize aromatic compounds. Taken together, this work supports OMV-mediated catabolism of lignin-derived aromatic compounds as an extracellular strategy for nutrient acquisition by soil bacteria and suggests that OMVs could potentially be useful tools for synthetic biology and biotechnological applications.

Low-Dose Aspirin during Pregnancy and Postpartum Bleeding.

OBJECTIVE: This study aimed to investigate whether aspirin 81 mg daily for preeclampsia prevention is associated with increased risk of postpartum blood loss at the time of delivery. STUDY DESIGN: This is a retrospective cohort study performed at a tertiary hospital from January 2018 to April 2021. Data were extracted from the electronic medical record. Patients prescribed low-dose aspirin (LDA) were compared with patients who were not. The primary outcome was a composite of postpartum blood loss, defined as: estimated blood loss (EBL) >1,000 mL, documentation of International Classification of Diseases-9/-10 codes for postpartum hemorrhage (PPH), or red blood cell (RBC) transfusion. Bivariate analysis, and unadjusted and adjusted logistic regression modeling were performed. RESULTS: Among 16,980 deliveries, 1,922 (11.3%) were prescribed LDA. Patients prescribed LDA were more likely to be >35 years old, nulliparous, obese, taking other anticoagulants, or have diagnoses of diabetes, systemic lupus erythematosus, fibroids, or hypertensive disease of pregnancy. After adjusting for potential confounders, the significant association between LDA use and the composite did not persist (adjusted odds ratio [aOR]: 1.1, 95% confidence interval [CI]: 1.0-1.3) nor did the association between EBL > 1,000 mL (aOR: 1.0, 95% CI: 0.9-1.3) and RBC transfusion (aOR: 1.3, 95% CI: 0.9-1.7). The association between LDA and PPH remained significant (aOR: 1.3, 95% CI: 1.1-1.6). Patients who discontinued LDA <7 days prior to delivery had an increased risk of the postpartum blood loss composite compared discontinuation ≥7 days (15.0 vs. 9.3%; p = 0.03). CONCLUSION: There may be an association between LDA use and increased risk of postpartum bleeding. This suggests that use of LDA outside the recommended guidelines should be cautioned and further investigation is needed to determine its ideal dosing and timing of discontinuation. KEY POINTS: · There may be an association with LDA and an increased risk of postpartum bleeding.. · Patients who discontinued LDA less than 7 days prior to delivery had an increased rate of postpartum bleeding.. · Additional research is need to determine optimal LDA dose and timing of discontinuation..