Immune imprinting, breadth of variant recognition, and germinal center response in human SARS-CoV-2 infection and vaccination.

During the SARS-CoV-2 pandemic, novel and traditional vaccine strategies have been deployed globally. We investigated whether antibodies stimulated by mRNA vaccination (BNT162b2), including third-dose boosting, differ from those generated by infection or adenoviral (ChAdOx1-S and Gam-COVID-Vac) or inactivated viral (BBIBP-CorV) vaccines. We analyzed human lymph nodes after infection or mRNA vaccination for correlates of serological differences. Antibody breadth against viral variants is lower after infection compared with all vaccines evaluated but improves over several months. Viral variant infection elicits variant-specific antibodies, but prior mRNA vaccination imprints serological responses toward Wuhan-Hu-1 rather than variant antigens. In contrast to disrupted germinal centers (GCs) in lymph nodes during infection, mRNA vaccination stimulates robust GCs containing vaccine mRNA and spike antigen up to 8 weeks postvaccination in some cases. SARS-CoV-2 antibody specificity, breadth, and maturation are affected by imprinting from exposure history and distinct histological and antigenic contexts in infection compared with vaccination.

Latitudinal patterns in stabilizing density dependence of forest communities.

Numerous studies have shown reduced performance in plants that are surrounded by neighbours of the same species1,2, a phenomenon known as conspecific negative density dependence (CNDD)3. A long-held ecological hypothesis posits that CNDD is more pronounced in tropical than in temperate forests4,5, which increases community stabilization, species coexistence and the diversity of local tree species6,7. Previous analyses supporting such a latitudinal gradient in CNDD8,9 have suffered from methodological limitations related to the use of static data10-12. Here we present a comprehensive assessment of latitudinal CNDD patterns using dynamic mortality data to estimate species-site-specific CNDD across 23 sites. Averaged across species, we found that stabilizing CNDD was present at all except one site, but that average stabilizing CNDD was not stronger toward the tropics. However, in tropical tree communities, rare and intermediate abundant species experienced stronger stabilizing CNDD than did common species. This pattern was absent in temperate forests, which suggests that CNDD influences species abundances more strongly in tropical forests than it does in temperate ones13. We also found that interspecific variation in CNDD, which might attenuate its stabilizing effect on species diversity14,15, was high but not significantly different across latitudes. Although the consequences of these patterns for latitudinal diversity gradients are difficult to evaluate, we speculate that a more effective regulation of population abundances could translate into greater stabilization of tropical tree communities and thus contribute to the high local diversity of tropical forests.

Large-scale migration into Britain during the Middle to Late Bronze Age.

Present-day people from England and Wales have more ancestry derived from early European farmers (EEF) than did people of the Early Bronze Age1. To understand this, here we generated genome-wide data from 793 individuals, increasing data from the Middle to the Late Bronze Age and Iron Age in Britain by 12-fold, and western and central Europe by 3.5-fold. Between 1000 and 875 BC, EEF ancestry increased in southern Britain (England and Wales) but not northern Britain (Scotland) due to incorporation of migrants who arrived at this time and over previous centuries, and who were genetically most similar to ancient individuals from France. These migrants contributed about half the ancestry of people of England and Wales from the Iron Age, thereby creating a plausible vector for the spread of early Celtic languages into Britain. These patterns are part of a broader trend of EEF ancestry becoming more similar across central and western Europe in the Middle to the Late Bronze Age, coincident with archaeological evidence of intensified cultural exchange2-6. There was comparatively less gene flow from continental Europe during the Iron Age, and the independent genetic trajectory in Britain is also reflected in the rise of the allele conferring lactase persistence to approximately 50% by this time compared to approximately 7% in central Europe where it rose rapidly in frequency only a millennium later. This suggests that dairy products were used in qualitatively different ways in Britain and in central Europe over this period.

A divergent protein kinase A regulatory subunit essential for morphogenesis of the human pathogen Leishmania.

Parasitic protozoa of the genus Leishmania cycle between the phagolysosome of mammalian macrophages, where they reside as rounded intracellular amastigotes, and the midgut of female sand flies, which they colonize as elongated extracellular promastigotes. Previous studies indicated that protein kinase A (PKA) plays an important role in the initial steps of promastigote differentiation into amastigotes. Here, we describe a novel regulatory subunit of PKA (which we have named PKAR3) that is unique to Leishmania and most (but not all) other Kinetoplastidae. PKAR3 is localized to subpellicular microtubules (SPMT) in the cell cortex, where it recruits a specific catalytic subunit (PKAC3). Promastigotes of pkar3 or pkac3 null mutants lose their elongated shape and become rounded but remain flagellated. Truncation of an N-terminal formin homology (FH)-like domain of PKAR3 results in its detachment from the SPMT, also leading to rounded promastigotes. Thus, the tethering of PKAC3 via PKAR3 at the cell cortex is essential for maintenance of the elongated shape of promastigotes. This role of PKAR3 is reminiscent of PKARIß and PKARIIß binding to microtubules of mammalian neurons, which is essential for the elongation of dendrites and axons, respectively. Interestingly, PKAR3 binds nucleoside analogs, but not cAMP, with a high affinity similar to the PKAR1 isoform of Trypanosoma. We propose that these early-diverged protists have re-purposed PKA for a novel signaling pathway that spatiotemporally controls microtubule remodeling and cell shape.

Asynchronous carbon sink saturation in African and Amazonian tropical forests.

Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions1-3. Climate-driven vegetation models typically predict that this tropical forest 'carbon sink' will continue for decades4,5. Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53-0.79), in contrast to the long-term decline in Amazonian forests6. Therefore the carbon sink responses of Earth's two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature7-9. Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth's intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth's climate.

Ancient DNA at the edge of the world: Continental immigration and the persistence of Neolithic male lineages in Bronze Age Orkney.

Orkney was a major cultural center during the Neolithic, 3800 to 2500 BC. Farming flourished, permanent stone settlements and chambered tombs were constructed, and long-range contacts were sustained. From ∼3200 BC, the number, density, and extravagance of settlements increased, and new ceremonial monuments and ceramic styles, possibly originating in Orkney, spread across Britain and Ireland. By ∼2800 BC, this phenomenon was waning, although Neolithic traditions persisted to at least 2500 BC. Unlike elsewhere in Britain, there is little material evidence to suggest a Beaker presence, suggesting that Orkney may have developed along an insular trajectory during the second millennium BC. We tested this by comparing new genomic evidence from 22 Bronze Age and 3 Iron Age burials in northwest Orkney with Neolithic burials from across the archipelago. We identified signals of inward migration on a scale unsuspected from the archaeological record: As elsewhere in Bronze Age Britain, much of the population displayed significant genome-wide ancestry deriving ultimately from the Pontic-Caspian Steppe. However, uniquely in northern and central Europe, most of the male lineages were inherited from the local Neolithic. This suggests that some male descendants of Neolithic Orkney may have remained distinct well into the Bronze Age, although there are signs that this had dwindled by the Iron Age. Furthermore, although the majority of mitochondrial DNA lineages evidently arrived afresh with the Bronze Age, we also find evidence for continuity in the female line of descent from Mesolithic Britain into the Bronze Age and even to the present day.

Vibrational Coupling Infrared Nanocrystallography.

Coupling between molecular vibrations leads to collective vibrational states with spectral features sensitive to local molecular order. This provides spectroscopic access to the low-frequency intermolecular energy landscape. In its nanospectroscopic implementation, this technique of vibrational coupling nanocrystallography (VCNC) offers information on molecular disorder and domain formation with nanometer spatial resolution. However, deriving local molecular order relies on prior knowledge of the transition dipole magnitude and crystal structure of the underlying ordered phase. Here we develop a quantitative model for VCNC by relating nano-FTIR collective vibrational spectra to the molecular crystal structure from X-ray crystallography. We experimentally validate our approach at the example of a metal organic porphyrin complex with a carbonyl ligand as the probe vibration. This framework establishes VCNC as a powerful tool for measuring low-energy molecular interactions, wave function delocalization, nanoscale disorder, and domain formation in a wide range of molecular systems.

Seizures Cause Prolonged Impairment of Ventilation, CO2 Chemoreception and Thermoregulation.

Sudden unexpected death in epilepsy (SUDEP) has been linked to respiratory dysfunction, but the mechanisms underlying this association remain unclear. Here we found that both focal and generalized convulsive seizures (GCSs) in epilepsy patients caused a prolonged decrease in the hypercapnic ventilatory response (HCVR; a measure of respiratory CO2 chemoreception). We then studied Scn1a R1407X/+ (Dravet syndrome; DS) and Scn8a N1768D/+ (D/+) mice of both sexes, two models of SUDEP, and found that convulsive seizures caused a postictal decrease in ventilation and severely depressed the HCVR in a subset of animals. Those mice with severe postictal depression of the HCVR also exhibited transient postictal hypothermia. A combination of blunted HCVR and abnormal thermoregulation is known to occur with dysfunction of the serotonin (5-hydroxytryptamine; 5-HT) system in mice. Depleting 5-HT with para-chlorophenylalanine (PCPA) mimicked seizure-induced hypoventilation, partially occluded the postictal decrease in the HCVR, exacerbated hypothermia, and increased postictal mortality in DS mice. Conversely, pretreatment with the 5-HT agonist fenfluramine reduced postictal inhibition of the HCVR and hypothermia. These results are consistent with the previous observation that seizures cause transient impairment of serotonergic neuron function, which would be expected to inhibit the many aspects of respiratory control dependent on 5-HT, including baseline ventilation and the HCVR. These results provide a scientific rationale to investigate the interictal and/or postictal HCVR as noninvasive biomarkers for those at high risk of seizure-induced death, and to prevent SUDEP by enhancing postictal 5-HT tone.SIGNIFICANCE STATEMENT There is increasing evidence that seizure-induced respiratory dysfunction contributes to the pathophysiology of sudden unexpected death in epilepsy (SUDEP). However, the cellular basis of this dysfunction has not been defined. Here, we show that seizures impair CO2 chemoreception in some epilepsy patients. In two mouse models of SUDEP we found that generalized convulsive seizures impaired CO2 chemoreception, and induced hypothermia, two effects reported with serotonergic neuron dysfunction. The defects in chemoreception and thermoregulation were exacerbated by chemical depletion of serotonin and reduced with fenfluramine, suggesting that seizure-induced respiratory dysfunction may be due to impairment of serotonin neuron function. These findings suggest that impaired chemoreception because of transient inhibition of serotonergic neurons may contribute to the pathophysiology of SUDEP.

Rare and de novo variants in 827 congenital diaphragmatic hernia probands implicate LONP1 as candidate risk gene.

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly that is often accompanied by other anomalies. Although the role of genetics in the pathogenesis of CDH has been established, only a small number of disease-associated genes have been identified. To further investigate the genetics of CDH, we analyzed de novo coding variants in 827 proband-parent trios and confirmed an overall significant enrichment of damaging de novo variants, especially in constrained genes. We identified LONP1 (lon peptidase 1, mitochondrial) and ALYREF (Aly/REF export factor) as candidate CDH-associated genes on the basis of de novo variants at a false discovery rate below 0.05. We also performed ultra-rare variant association analyses in 748 affected individuals and 11,220 ancestry-matched population control individuals and identified LONP1 as a risk gene contributing to CDH through both de novo and ultra-rare inherited largely heterozygous variants clustered in the core of the domains and segregating with CDH in affected familial individuals. Approximately 3% of our CDH cohort who are heterozygous with ultra-rare predicted damaging variants in LONP1 have a range of clinical phenotypes, including other anomalies in some individuals and higher mortality and requirement for extracorporeal membrane oxygenation. Mice with lung epithelium-specific deletion of Lonp1 die immediately after birth, most likely because of the observed severe reduction of lung growth, a known contributor to the high mortality in humans. Our findings of both de novo and inherited rare variants in the same gene may have implications in the design and analysis for other genetic studies of congenital anomalies.

Recurrence and Survival After Minimally Invasive and Open Esophagectomy for Esophageal Cancer: A Post Hoc Analysis of the Ensure Study.

OBJECTIVE: To determine the impact of operative approach [open (OE), hybrid minimally invasive (HMIE), and total minimally invasive (TMIE) esophagectomy] on operative and oncologic outcomes for patients treated with curative intent for esophageal and junctional cancer. BACKGROUND: The optimum oncologic surgical approach to esophageal and junctional cancer is unclear. METHODS: This secondary analysis of the European multicenter ENSURE study includes patients undergoing curative-intent esophagectomy for cancer between 2009 and 2015 across 20 high-volume centers. Primary endpoints were disease-free survival (DFS) and the incidence and location of disease recurrence. Secondary endpoints included among others R0 resection rate, lymph node yield, and overall survival (OS). RESULTS: In total, 3199 patients were included. Of these, 55% underwent OE, 17% HMIE, and 29% TMIE. DFS was independently increased post-TMIE [hazard ratio (HR): 0.86 (95% CI: 0.76-0.98), P = 0.022] compared with OE. Multivariable regression demonstrated no difference in absolute locoregional recurrence risk according to the operative approach [HMIE vs OE, odds ratio (OR): 0.79, P = 0.257; TMIE vs OE, OR: 0.84, P = 0.243]. The probability of systemic recurrence was independently increased post-HMIE (OR: 2.07, P = 0.031), but not TMIE (OR: 0.86, P = 0.508). R0 resection rates ( P = 0.005) and nodal yield ( P < 0.001) were independently increased after TMIE, but not HMIE ( P = 0.424; P = 0.512) compared with OE. OS was independently improved following both HMIE (HR: 0.79, P = 0.009) and TMIE (HR: 0.82, P = 0.003) as compared with OE. CONCLUSION: In this European multicenter study, TMIE was associated with improved surgical quality and DFS, whereas both TMIE and HMIE were associated with improved OS as compared with OE for esophageal cancer.

The Prognostic Impact of Minimally Invasive Esophagectomy on Survival after Esophagectomy following a Delayed Interval after Chemoradiotherapy; A Secondary Analysis of the DICE Study.

OBJECTIVE: To evaluate prognostic differences between minimally invasive esophagectomy (MIE) and open esophagectomy (OE) in patients with surgery after a prolonged interval (>12 wk) following chemoradiotherapy (CRT). BACKGROUND: Previously, we established that a prolonged interval after CRT prior to esophagectomy was associated with poorer long-term survival. METHODS: This was an international multi-center cohort study involving seventeen tertiary centers, including patients who received CRT followed by surgery between 2010-2020. Patients undergoing MIE were defined as thoracoscopic and laparoscopic approach. RESULTS: 428 patients (145 MIE and 283 OE) had surgery between 12 weeks and two years after CRT. Significant differences were observed in ASA grade, radiation dose, clinical T stage, and histological subtype. There were no significant differences between the groups in age, sex, BMI, pathological T or N stage, resection margin status, tumor location, surgical technique, or 90-day mortality. Survival analysis showed MIE was associated with improved survival in univariate (P=0.014), multivariate analysis after adjustment for smoking, T and N stage, and histology (HR=1.69; 95% CI 1.14 to 2.5) and propensity matched analysis (P=0.02). Further subgroup analyses by radiation dose and interval after CRT showed survival advantage for MIE, in 40-50Gy dose groups (HR=1.9; 95% CI 1.2 to 3.0), and in patients having surgery within six months of CRT (HR=1.6; 95% CI 1.1 to 2.2). CONCLUSION: MIE was associated with an improved overall survival compared to OE in patients with a prolonged interval from CRT to surgery. The mechanism for this observed improvement in survival remains unknown, with potential hypotheses including a reduction in complications and improved functional recovery after MIE.

Differences in the impact of the COVID-19 pandemic in the long-term trajectories of life satisfaction by sex in the UK: a prospective cohort study.

BACKGROUND: The COVID-19 pandemic has disproportionately affected women's mental health, with most evidence focused on mental ill-health outcomes. Previous research suggests that differences in time-use might explain this disparity, as women generally spent more time doing psychologically taxing activities than men. We investigated (1) sex differences in the impact of the pandemic in the long-term trajectories of life satisfaction and (2) whether time-use differences partly explained that differential impact. METHODS: In this prospective cohort study, we used the 1970 British Cohort Study, a birth cohort representing people born in Great Britain in 1970. Since 1970, information has been collected for all cohort members every 4-10 years (ten sweeps). Additional data were collected at three timepoints during the pandemic (May 2020, September-October 2020, February-March 2021) as part of the COVID-19 Survey. Response rates within the target population ranged between 23·6% (May, 2020) and 32·5% (March, 2021) in the COVID-19 Survey. We used non-response weights to restore sample representativeness to the target population (cohort members alive and residing in the UK during the pandemic). Life satisfaction was prospectively assessed at ages 26 (1996), 30, 34, 42, 46, 50, 50·5, and 51 years (2021) using a single question with responses ranging from 0 (lowest life satisfaction) to 10 (highest life satisfaction). We used multiple-group piecewise latent growth curve models grouped by sex assigned at birth. Additional models were adjusted for self-reported number of hours spent working, volunteering, home-schooling children, taking care of children and other people, and doing housework during the pandemic. Participants provided verbal informed consent. Ethics approval was not sought as non-sensitive, open-access data with minimal risk of identification was used. FINDINGS: We analysed data from 6766 adults (3799 [56·2%] women and 2967 [43·8%] men). Compared with men, women had consistently higher levels of life satisfaction before the pandemic (Δintercept,unadjusted = 0·213, 95% CI 0·087 to 0·340, p=0·0009), and experienced a more accelerated decline with its onset (Δquad2,unadjusted = -0·018, -0·026 to -0·011; p<0·0001), even after accounting for time use (Δquad2,adjusted = -0·016, -0·031 to -0·001; p=0·0348). Results were robust to adjustment for concurrent financial and occupational situation (Δquad2,adjustedfull = -0·019, -0·035 to -0·004; p=0·0158). INTERPRETATION: Our study shows sex inequalities in the impact of the pandemic on the long-term life satisfaction trajectories of adults in their 50s. Self-reported time-use differences did not account for these inequalities. One of the limitations is that we relied on self-reported time-use and were not able to include factors like the so-called mental load (being responsible for organising or monitoring activities, regardless of being involved in their execution), which might partly explain these results. FUNDING: Economic and Social Research Council (ESRC) Centre for Society and Mental Health at King's College London.

Combining Thermal Desorption with Selected Ion Flow Tube Mass Spectrometry for Analyses of Breath Volatile Organic Compounds.

An instrument integrating thermal desorption (TD) to selected ion flow tube mass spectrometry (SIFT-MS) is presented, and its application to analyze volatile organic compounds (VOCs) in human breath is demonstrated for the first time. The rationale behind this development is the need to analyze breath samples in large-scale multicenter clinical projects involving thousands of patients recruited in different hospitals. Following adapted guidelines for validating analytical techniques, we developed and validated a targeted analytical method for 21 compounds of diverse chemical class, chosen for their clinical and biological relevance. Validation has been carried out by two independent laboratories, using calibration standards and real breath samples from healthy volunteers. The merging of SIFT-MS and TD integrates the rapid analytical capabilities of SIFT-MS with the capacity to collect breath samples across multiple hospitals. Thanks to these features, the novel instrument has the potential to be easily employed in clinical practice.

Tropifexor plus cenicriviroc combination versus monotherapy in nonalcoholic steatohepatitis: Results from the phase 2b TANDEM study.

BACKGROUND AND AIMS: With distinct mechanisms of action, the combination of tropifexor (TXR) and cenicriviroc (CVC) may provide an effective treatment for NASH. This randomized, multicenter, double-blind, phase 2b study assessed the safety and efficacy of TXR and CVC combination, compared with respective monotherapies. APPROACH AND RESULTS: Patients (N = 193) were randomized 1:1:1:1 to once-daily TXR 140 µg (TXR 140 ), CVC 150 mg (CVC), TXR 140 µg + CVC 150 mg (TXR 140 + CVC), or TXR 90 µg + CVC 150 mg (TXR 90 + CVC) for 48 weeks. The primary and secondary end points were safety and histological improvement, respectively. Rates of adverse events (AEs) were similar across treatment groups. Pruritus was the most frequently experienced AE, with highest incidence in the TXR 140 group (40.0%). In TXR and combination groups, alanine aminotransferase (ALT) decreased from baseline to 48 weeks (geometric mean change: -21%, TXR 140 ; -16%, TXR 140 + CVC; -13%, TXR 90 + CVC; and +17%, CVC). Reductions in body weight observed at week 24 (mean changes from baseline: TXR 140 , -2.5 kg; TXR 140 + CVC, -1.7 kg; TXR 90 + CVC, -1.0 kg; and CVC, -0.1 kg) were sustained to week 48. At least 1-point improvement in fibrosis stage/steatohepatitis resolution without worsening of fibrosis was observed in 32.3%/25.8%, 31.6%/15.8%, 29.7%/13.5%, and 32.5%/22.5% of patients in the TXR 140 , CVC, TXR 140 + CVC, and TXR 90 + CVC groups, respectively. CONCLUSIONS: The safety profile of TXR + CVC combination was similar to respective monotherapies, with no new signals. TXR monotherapy showed sustained ALT and body weight decreases. No substantial incremental efficacy was observed with TXR + CVC combination on ALT, body weight, or in histological end points compared with monotherapy.

A macrophage-cell model of HIV latency reveals the unusual importance of the bromodomain axis.

BACKGROUND: Although macrophages are now recognized as an essential part of the HIV latent reservoir, whether and how viral latency is established and reactivated in these cell types is poorly understood. To understand the fundamental mechanisms of viral latency in macrophages, there is an urgent need to develop latency models amenable to genetic manipulations and screening for appropriate latency-reversing agents (LRAs). Given that differentiated THP-1 cells resemble monocyte-derived macrophages in HIV replication mechanisms, we set out to establish a macrophage cell model for HIV latency using THP-1 cells. METHODS: We created single-cell clones of THP-1 cells infected with a single copy of the dual-labeled HIVGKO in which a codon switched eGFP (csGFP) is under the control of the HIV-1 5' LTR promoter, and a monomeric Kusabira orange 2 (mKO2) under the control of cellular elongation factor one alpha promoter (EF1α). Latently infected cells are csGFP-, mKO2+, while cells with actively replicating HIV (or reactivated virus) are csGFP+,mKO2+. After sorting for latently infected cells, each of the THP-1 clones with unique integration sites for HIV was differentiated into macrophage-like cells with phorbol 12-myristate 13-acetate (PMA) and treated with established LRAs to stimulate HIV reactivation. Monocyte-derived macrophages (MDMs) harboring single copies of HIVGKO were used to confirm our findings. RESULTS: We obtained clones of THP-1 cells with latently infected HIV with unique integration sites. When the differentiated THP-1 or primary MDMs cells were treated with various LRAs, the bromodomain inhibitors JQ1 and I-BET151 were the most potent compounds. Knockdown of BRD4, the target of JQ1, resulted in increased reactivation, thus confirming the pharmacological effect. The DYRK1A inhibitor Harmine and lipopolysaccharide (LPS) also showed significant reactivation across all three MDM donors. Remarkably, LRAs like PMA/ionomycin, bryostatin-1, and histone deacetylase inhibitors known to potently reactivate latent HIV in CD4 + T cells showed little activity in macrophages. CONCLUSIONS: Our results indicate that this model could be used to screen for appropriate LRAs for macrophages and show that HIV latency and reactivation mechanisms in macrophages may be distinct from those of CD4 + T cells.

Extracorporeal life support without systemic anticoagulation: a nitric oxide-based non-thrombogenic circuit for the artificial placenta in an ovine model.

BACKGROUND: Clinical translation of the extracorporeal artificial placenta (AP) is impeded by the high risk for intracranial hemorrhage in extremely premature newborns. The Nitric Oxide Surface Anticoagulation (NOSA) system is a novel non-thrombogenic extracorporeal circuit. This study aims to test the NOSA system in the AP without systemic anticoagulation. METHODS: Ten extremely premature lambs were delivered and connected to the AP. For the NOSA group, the circuit was coated with DBHD-N2O2/argatroban, 100 ppm nitric oxide was blended into the sweep gas, and no systemic anticoagulation was given. For the Heparin control group, a non-coated circuit was used and systemic anticoagulation was administered. RESULTS: Animals survived 6.8 ± 0.6 days with normal hemodynamics and gas exchange. Neither group had any hemorrhagic or thrombotic complications. ACT (194 ± 53 vs. 261 ± 86 s; p < 0.001) and aPTT (39 ± 7 vs. 69 ± 23 s; p < 0.001) were significantly lower in the NOSA group than the Heparin group. Platelet and leukocyte activation did not differ significantly from baseline in the NOSA group. Methemoglobin was 3.2 ± 1.1% in the NOSA group compared to 1.6 ± 0.6% in the Heparin group (p < 0.001). CONCLUSIONS: The AP with the NOSA system successfully supported extremely premature lambs for 7 days without significant bleeding or thrombosis. IMPACT: The Nitric Oxide Surface Anticoagulation (NOSA) system provides effective circuit-based anticoagulation in a fetal sheep model of the extracorporeal artificial placenta (AP) for 7 days. The NOSA system is the first non-thrombogenic circuit to consistently obviate the need for systemic anticoagulation in an extracorporeal circuit for up to 7 days. The NOSA system may allow the AP to be implemented clinically without systemic anticoagulation, thus greatly reducing the intracranial hemorrhage risk for extremely low gestational age newborns. The NOSA system could potentially be applied to any form of extracorporeal life support to reduce or avoid systemic anticoagulation.

Therapeutic efficacy of generic artemether-lumefantrine in the treatment of uncomplicated malaria in Ghana: assessing anti-malarial efficacy amidst pharmacogenetic variations.

BACKGROUND: Despite efforts made to reduce morbidity and mortality associated with malaria, especially in sub-Saharan Africa, malaria continues to be a public health concern that requires innovative efforts to reach the WHO-set zero malaria agenda. Among the innovations is the use of artemisinin-based combination therapy (ACT) that is effective against Plasmodium falciparum. Generic artemether-lumefantrine (AL) is used to treat uncomplicated malaria after appropriate diagnosis. AL is metabolized by the cytochrome P450 family of enzymes, such as CYP2B6, CYP3A4 and CYP3A5, which can be under pharmacogenetic influence. Pharmacogenetics affecting AL metabolism, significantly influence the overall anti-malarial activity leading to variable therapeutic efficacy. This study focused on generic AL drugs used in malarial treatment as prescribed at health facilities and evaluated pharmacogenomic influences on their efficacy. METHODS: Patients who have been diagnosed with malaria and confirmed through RDT and microscopy were recruited in this study. Blood samples were taken on days 1, 2, 3 and 7 for parasite count and blood levels of lumefantrine, artemisinin, desbutyl-lumefantrine (DBL), and dihydroartemisinin (DHA), the active metabolites of lumefantrine and artemether, respectively, were analysed using established methods. Pharmacogene variation analysis was undertaken using iPLEX microarray and PCR-RFLP. RESULTS: A total of 52 patients completed the study. Median parasite density from day 1 to 7 ranged from 0-2666/µL of blood, with days 3 and 7 recording 0 parasite density. Highest median plasma concentration for lumefantrine and desbutyl lumefantrine, which are the long-acting components of artemisinin-based combinations, was 4123.75 ng/mL and 35.87 ng/mL, respectively. Day 7 plasma lumefantrine concentration across all generic ACT brands was ≥ 200 ng/mL which potentially accounted for the parasitaemia profile observed. Monomorphism was observed for CYP3A4 variants, while there were observed variations in CYP2B6 and CYP3A5 alleles. Among the CYP3A5 genotypes, significant differences in genotypes and plasma concentration for DBL were seen on day 3 between 1/*1 versus *1/*6 (p = 0.002), *1/*3 versus *1/*6 (p = 0.006) and *1/*7 versus *1/*6 (p = 0.008). Day 7 plasma DBL concentrations showed a significant difference between *1/*6 and *1/*3 (p = 0.026) expressors. CONCLUSIONS: The study findings show that CYP2B6 and CYP3A5 pharmacogenetic variations may lead to higher plasma exposure of AL metabolites.

Efficacy, Feasibility, and Safety of the X-Tack Endoscopic HeliX Tacking System: A Multicenter Experience.

BACKGROUND AND AIMS: The application of endoscopic suturing has revolutionized defect closures. Conventional over-the-scope suturing necessitates removal of the scope, placement of the device, and reinsertion. A single channel, single sequence, through-the-scope suturing device has been developed to improve this process. This study aims to describe the efficacy, feasibility, and safety of a through-the-scope suturing device for gastrointestinal defect closure. METHODS: This was a retrospective multicenter study involving 9 centers of consecutive adult patients who underwent suturing using the X-Tack Endoscopic HeliX Tacking System (Apollo Endosurgery). The primary outcomes were technical success and long-term clinical success. Secondary outcomes included adverse events, recurrence, and reintervention rates. RESULTS: In all, 56 patients (mean age 53.8, 33 women) were included. Suturing indications included fistula repair (n=22), leak repair (n=7), polypectomy defect closure (n=12), peroral endoscopic myotomy (POEM) site closure (n=7), perforation repair (n=6), and ulcers (n=2). Patients were followed at a mean duration of 74 days. Overall technical and long-term clinical success rates were 92.9% and 75%, respectively. Both technical and clinical success rates were 100% for polypectomies, POEM-site closures, and ulcers. Success rates were lower for the repair of fistulas (95.5% technical, 54.5% clinical), leaks (57.1%, 28.6%), and perforations (100%, 66.7%). No immediate adverse events were noted. CONCLUSION: This novel, through-the-scope endoscopic suturing system, is a safe and feasible method to repair defects that are ≤3 cm. The efficacy of this device may be better suited for superficial defects as opposed to full-thickness defects. Larger defects will need more sutures and probably a double closure technique to provide a reinforcement layer.

Using genetic data to strengthen causal inference in observational research.

Causal inference is essential across the biomedical, behavioural and social sciences.By progressing from confounded statistical associations to evidence of causal relationships, causal inference can reveal complex pathways underlying traits and diseases and help to prioritize targets for intervention. Recent progress in genetic epidemiology - including statistical innovation, massive genotyped data sets and novel computational tools for deep data mining - has fostered the intense development of methods exploiting genetic data and relatedness to strengthen causal inference in observational research. In this Review, we describe how such genetically informed methods differ in their rationale, applicability and inherent limitations and outline how they should be integrated in the future to offer a rich causal inference toolbox.

Life-course social participation and physical activity in midlife: longitudinal associations in the 1970 British Cohort Study (BCS70).

A hypothesized benefit of social participation is that it encourages people to be more physically active. However, limited evidence exists on the association between social participation over the life-course and physical activity in midlife. We sought to apply a life-course framework to examine the association of social participation and device measured physical activity in midlife in the UK. We used the 1970 British Birth Cohort Study (BCS70), which includes all people born in Britain during a single week in 1970. Social participation was assessed at ages 16, 30, 34 and 42. Physical activity was measured by accelerometery at age 46, as mean daily step count and time spent in moderate to vigorous physical activity (MVPA). The associations of social participation and physical activity were tested using two different life-course models: the sensitive period model and the accumulation model. Individuals with medium and high participation compared to no social participation over their life-course had higher mean daily step count and MVPA in midlife, supporting the accumulation model. In the sensitive period model, only those that actively participated at age 42 had higher mean daily steps and MVPA compared to those who did not participate. Our study provides empirical evidence on the importance of sustaining social participation at all ages over the life-course rather than at a particular timepoint of someone's life. If our findings reflect causal effects, interventions to promote social participation throughout the life-course could be an avenue to promote physical activity in middle life.