Outcomes Following a False-Positive Multi-Cancer Early Detection Test: Results from DETECT-A, the First Large, Prospective, Interventional MCED Study.

Guideline recommended standard of care screening is available for four cancer types; most cancer-related deaths are caused by cancers without standard of care screening. DETECT-A is the first prospective interventional trial evaluating a multi-cancer early detection (MCED) blood test (CancerSEEK) in women without a history of cancer, providing the first opportunity to assess the long-term outcomes of individuals with false-positive (FP) MCED results. This prospective analysis of DETECT-A participants with FP results evaluates the performance of an imaging-based diagnostic workflow and examines cancer risk following a FP result. This analysis included all DETECT-A participants with a positive CancerSEEK test and subsequent flourine-18 fluorodeoxyglucose positron emission tomography-IV contrast-enhanced computed tomography (18-F-FDG PET-CT) imaging and clinical workup indicating no evidence of cancer within 1 year of enrollment (n = 98). Medical records, study interactions, and study surveys were used to assess cancer incidence, treatments, and clinical outcomes through August 2023. Ninety-five of 98 participants with a FP result remained cancer-free with a median follow-up of 3.6 years (IQR: 2.5-4.1) from determination of FP status. Three incident cancers were observed over the follow-up period. One bilateral stage IIIC ovarian cancer was diagnosed 1.9 years after determination of FP status; two stage I breast cancers were diagnosed 0.1 and 1.6 years from determination of FP status. The annual incidence rate of cancer during follow-up from FP determination was 1.0% (95% confidence interval, 0.2%-2.8%). Participants with a positive CancerSEEK test who underwent 18-F-FDG PET-CT and clinical workup without cancer findings had low risk for cancer over the following several years. Prevention Relevance: This study provides multiyear clinical outcomes data following a false-positive multi-cancer early detection test for individuals participating in a prospective interventional trial. It provides a preliminary performance assessment of an imaging-based diagnostic workflow following a false-positive multi-cancer early detection test.

Mixed responses to targeted therapy driven by chromosomal instability through p53 dysfunction and genome doubling.

The phenomenon of mixed/heterogenous treatment responses to cancer therapies within an individual patient presents a challenging clinical scenario. Furthermore, the molecular basis of mixed intra-patient tumor responses remains unclear. Here, we show that patients with metastatic lung adenocarcinoma harbouring co-mutations of EGFR and TP53, are more likely to have mixed intra-patient tumor responses to EGFR tyrosine kinase inhibition (TKI), compared to those with an EGFR mutation alone. The combined presence of whole genome doubling (WGD) and TP53 co-mutations leads to increased genome instability and genomic copy number aberrations in genes implicated in EGFR TKI resistance. Using mouse models and an in vitro isogenic p53-mutant model system, we provide evidence that WGD provides diverse routes to drug resistance by increasing the probability of acquiring copy-number gains or losses relative to non-WGD cells. These data provide a molecular basis for mixed tumor responses to targeted therapy, within an individual patient, with implications for therapeutic strategies.

Omega-3 Polyunsaturated Fatty Acids with Adipose Tissue Inflammation: Longitudinal Analysis in the PROMISE Cohort.

OBJECTIVES: Although pre-clinical studies have shown a beneficial impact of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) on adipose (AT) inflammation, the current literature from human studies is limited. Therefore, we aimed to evaluate the longitudinal associations of circulating levels of n-3 PUFAs with biomarkers of AT inflammation. METHODS: Longitudinal data from participants in the PROMISE cohort (n = 474) were used. AT inflammation was measured using circulating biomarkers at baseline and up to 2 follow-up visits. n-3 PUFAs were measured at baseline in four serum lipid fractions. Generalized estimating equations (GEE) analyses evaluated longitudinal associations between n-3 PUFAs and AT inflammation, adjusting for covariates. RESULTS: Fully adjusted GEE models indicated that higher baseline proportions of eicosapentaenoic acid (EPA), n-3 docosapentaenoic acid (n-3 DPA), and docosahexaenoic acid (DHA) in total serum were significantly inversely associated with longitudinal change in soluble CD163 (sCD163) (all p < 0.05). A significant positive association of n-3 DPA and DHA with longitudinal change in adiponectin (p < 0.05) was also observed. Generally consistent associations were observed between n-3 PUFAs and sCD163 and adiponectin in the four lipid fractions. CONCLUSIONS: These findings will add to the limited evidence on the potential role n-3 PUFAs have in the prevention and management of AT inflammation in humans and may help inform future interventions targeting chronic inflammation at the level of AT.

Discrete Relationships between Spatiotemporal Gait Characteristics and Domain-Specific Neuropsychological Performance in Midlife.

Midlife risk factors such as type 2 diabetes mellitus (T2DM) confer a significantly increased risk of cognitive impairment in later life with executive function, memory, and attention domains often affected first. Spatiotemporal gait characteristics are emerging as important integrative biomarkers of neurocognitive function and of later dementia risk. We examined 24 spatiotemporal gait parameters across five domains of gait previously linked to cognitive function on usual-pace, maximal-pace, and cognitive dual-task gait conditions in 102 middle-aged adults with (57.5 ± 8.0 years; 40% female) and without (57.0 ± 8.3 years; 62.1% female) T2DM. Neurocognitive function was measured using a neuropsychological assessment battery. T2DM was associated with significant changes in gait phases and rhythm domains at usual pace, and greater gait variability observed during maximal pace and dual tasks. In the overall cohort, both the gait pace and rhythm domains were associated with memory and executive function during usual pace. At maximal pace, gait pace parameters were associated with reaction time and delayed memory. During the cognitive dual task, associations between gait variability and both delayed memory/executive function were observed. Associations persisted following covariate adjustment and did not differ by T2DM status. Principal components analysis identified a consistent association of slower gait pace (step/stride length) and increased gait variability during maximal-pace walking with poorer memory and executive function performance. These data support the use of spatiotemporal gait as an integrative biomarker of neurocognitive function in otherwise healthy middle-aged individuals and reveal discrete associations between both differing gait tasks and gait domains with domain-specific neuropsychological performance. Employing both maximal-pace and dual-task paradigms may be important in cognitively unimpaired populations with risk factors for later cognitive decline-with the aim of identifying individuals who may benefit from potential preventative interventions.

Pulmonologists' Attitudes and Role in Precision Medicine Biomarker Testing for Non-Small Cell Lung Cancer.

BACKGROUND: Despite advances in precision medicine for non-small cell lung cancer (NSCLC), biomarker testing for these therapies remain frequently underutilized, delayed, and inequitable. Pulmonologists often play a critical role in the initial diagnostic steps for patients with lung cancer and previous data show variability in their knowledge and practices regarding biomarker testing. The purpose of this study is to better understand how pulmonologists' view their role in lung cancer care. RESEARCH QUESTION: With the increasing importance of biomarker testing and precision medicine, how do pulmonologists view their role in lung cancer care? STUDY DESIGN: An electronic survey consisting of 31 items focused on attitudes and practices regarding diagnostic steps for NSCLC was randomly distributed to a sample of practicing pulmonologists in the American College of Chest Physicians (CHEST) Analytics database. Inferential statistics were performed using Chi2 tests and multivariable logistic regression models. RESULTS: A total of 401 pulmonologists responded to the survey. The majority (92%) were general pulmonologists, and over half (62%) indicate they order biomarker testing. Longer practice tenure, higher case volumes, and participation in a multidisciplinary tumor board were associated with ordering biomarkers (p<0.05). Pulmonology was identified to have the leading responsibility for the initial diagnostic biopsy by most respondents (83%) and less often for staging (45%), leading discussions about biomarker testing with patients (28%), and for ordering biomarkers (22%). The most common reasons for not ordering biomarkers included: oncology was responsible (84%), it is not within their scope of practice (46%), or lack of the necessary knowledge (51%). INTERPRETATION: Pulmonologists vary in their practices for ordering biomarkers and many defer this responsibility to oncology. Despite the role of bronchoscopy and pulmonology societal guidelines for staging, many defer leadership of this process. Many pulmonologists lack the necessary resources and multi-disciplinary infrastructure likely required to efficiently accomplish biomarker testing.

Co-expression analysis reveals distinct alliances around two carbon fixation pathways in hydrothermal vent symbionts.

Most autotrophic organisms possess a single carbon fixation pathway. The chemoautotrophic symbionts of the hydrothermal vent tubeworm Riftia pachyptila, however, possess two functional pathways: the Calvin-Benson-Bassham (CBB) and the reductive tricarboxylic acid (rTCA) cycles. How these two pathways are coordinated is unknown. Here we measured net carbon fixation rates, transcriptional/metabolic responses and transcriptional co-expression patterns of Riftia pachyptila endosymbionts by incubating tubeworms collected from the East Pacific Rise at environmental pressures, temperature and geochemistry. Results showed that rTCA and CBB transcriptional patterns varied in response to different geochemical regimes and that each pathway is allied to specific metabolic processes; the rTCA is allied to hydrogenases and dissimilatory nitrate reduction, whereas the CBB is allied to sulfide oxidation and assimilatory nitrate reduction, suggesting distinctive yet complementary roles in metabolic function. Furthermore, our network analysis implicates the rTCA and a group 1e hydrogenase as key players in the physiological response to limitation of sulfide and oxygen. Net carbon fixation rates were also exemplary, and accordingly, we propose that co-activity of CBB and rTCA may be an adaptation for maintaining high carbon fixation rates, conferring a fitness advantage in dynamic vent environments.

Efficacy of virtual surgical planning and a three-dimensional-printed, patient-specific reduction system to facilitate alignment of diaphyseal tibial fractures stabilized by minimally invasive plate osteosynthesis in dogs: A prospective clinical study.

OBJECTIVE: To evaluate the efficacy of a three-dimensional (3D)-printed, patient-specific reduction system for aligning diaphyseal tibial fractures stabilized using minimally invasive plate osteosynthesis (MIPO). STUDY DESIGN: Prospective clinical trial. SAMPLE POPULATION: Fifteen client owned dogs. METHODS: Virtual 3D models of both pelvic limbs were created. Pin guides were designed to conform to the proximal and distal tibia. A reduction bridge was designed to align the pin guides based on the guides' spatial location. Guides were 3D printed, sterilized, and applied, in conjunction with transient application of a circular fixator, to facilitate indirect fracture realignment before plate application. Alignment of the stabilized tibiae was assessed using postoperative computed tomography scans. RESULTS: Mean duration required for virtual planning was 2.5 h and a mean of 50.7 h elapsed between presentation and surgery. Guide placement was accurate with minor median discrepancies in translation and frontal, sagittal, and axial plane positioning of 2.9 mm, 3.6°, 2.7°, and 6.8°, respectively. Application of the reduction system restored mean tibial length and frontal, sagittal, and axial alignment within 1.7 mm, 1.9°, 1.7°, and 4.5°, respectively, of the contralateral tibia. CONCLUSION: Design and fabrication of a 3D-printed, patient-specific fracture reduction system is feasible in a relevant clinical timeline. Intraoperative pin-guide placement was reasonably accurate with minor discrepancies compared to the virtual plan. Custom 3D-printed reduction system application facilitated near-anatomic or acceptable fracture reduction in all dogs. CLINICAL SIGNIFICANCE: Virtual planning and fabrication of a 3D-printing patient-specific fracture reduction system is practical and facilitated acceptable, if not near-anatomic, fracture alignment during MIPO.

Serum measures of docosahexaenoic acid (DHA) synthesis underestimates whole body DHA synthesis in male and female mice.

Females have higher docosahexaenoic acid (DHA) levels than males, proposed to be a result of higher DHA synthesis rates from α-linolenic acid (ALA). However, DHA synthesis rates are reported to be low, and have not been directly compared between sexes. Here, we apply a new compound specific isotope analysis model to determine n-3 PUFA synthesis rates in male and female mice and assess its potential translation to human populations. Male and female C57BL/6N mice were allocated to one of three 12-week dietary interventions with added ALA, eicosapentaenoic acid (EPA) or DHA. The diets included low carbon-13 (δ13C)-n-3 PUFA for four weeks, followed by high δ13C-n-3 PUFA for eight weeks (n=4 per diet, time point, sex). Following the diet switch, blood and tissues were collected at multiple time points, and fatty acid levels and δ13C were determined and fit to one-phase exponential decay modeling. Hepatic DHA synthesis rates were not different (P>.05) between sexes. However, n-3 docosapentaenoic acid (DPAn-3) synthesis from dietary EPA was 66% higher (P<.05) in males compared to females, suggesting higher synthesis downstream of DPAn-3 in females. Estimates of percent conversion of dietary ALA to serum DHA was 0.2%, in line with previous rodent and human estimates, but severely underestimates percent dietary ALA conversion to whole body DHA of 9.5%. Taken together, our data indicates that reports of low human DHA synthesis rates may be inaccurate, with synthesis being much higher than previously believed. Future animal studies and translation of this model to humans are needed for greater understanding of n-3 PUFA synthesis and metabolism, and whether the higher-than-expected ALA-derived DHA can offset dietary DHA recommendations set by health agencies.

X-ray Spectroscopy at the SuperXAS and Debye Beamlines: from in situ to Operando.

Understanding structure-performance relationships are essential for the rational design of new functional materials or in the further optimization of (catalytic) processes. Due to the high penetration depth of the radiation used, synchrotron-based hard X-ray techniques (with energy > 4.5 keV) allow the study of materials under realistic conditions (in situ and operando) and thus play an important role in uncovering structure-performance relationships. X-ray absorption and emission spectroscopies (XAS and XES) give insight into the electronic structure (oxidation state, spin state) and local geometric structure (type and number of nearest neighbor atoms, bond distances, disorder) up to ~5 Å around the element of interest. In this mini review, we will give an overview of the in situ and operando capabilities of the SuperXAS beamline, a facility for hard X-ray spectroscopy, through recent examples from studies of heterogeneous catalysts, electrochemical systems, and photoinduced processes. The possibilities for time-resolved experiments in the time range from ns to seconds and longer are illustrated. The extension of X-ray spectroscopy at the new Debye beamline combined with operando X-ray scattering and diffraction and further developments of time-resolved XES at SuperXAS will open new possibilities after the Swiss Light Source upgrade mid 2025.

Sex-dependent differences in tissue and blood n-3 PUFA levels following ALA or ALA + DHA feeding of liver-specific Elovl2-KO and control mice.

Docosahexaenoic acid (DHA, 22:6n-3) must be consumed from the diet or synthesized from polyunsaturated fatty acid (PUFA) precursors, such as α-linolenic acid (ALA, 18:3n-3). Elongase 2 (encoded by Elovl2 gene) catalyzes two elongation reactions in the PUFA biosynthesis pathway and may be important in regulating the observed sex differences in n-3 PUFA levels. Our aim was to determine how targeted knockout of liver Elovl2 affects tissue and blood n-3 PUFA levels in male and female C57BL/6J mice. Twenty-eight-day old male and female liver Elovl2-KO and control mice were placed onto one of two dietary protocols for a total of 8 weeks (4-8 mice per genotype, per diet, per sex): 1) an 8-week 2 % ALA in total fat diet or 2) a 4-week 2 % ALA diet followed by a 4-week 2 % ALA + 2 % DHA diet. Following this 8-week feeding period, 12-week-old mice were sacrificed and serum, red blood cells (RBC), liver, heart and brain were collected and fatty acid levels measured. Significant interaction effects (p < 0.05, sex x genotype) for serum, RBC, liver and heart DHA levels were identified. In serum and liver, DHA levels were significantly different (p < 0.01) between all groups with male controls > female controls > female KO > male KO in serum and female controls > male controls > female KO > male KO in liver. In RBCs and the heart, female controls = male controls > female KO > male KO (p < 0.001). The addition of DHA to diet removed the interaction effects on DHA levels in the serum, liver and heart, yielding a significant sex effect in serum, liver (female > male, p < 0.01) and brain (male > female, p < 0.05) and genotype effect in serum and heart (control > KO, p < 0.05). Ablation of liver Elovl2 results in significantly lower blood and tissue DHA in a sex-dependent manner, suggesting a role for Elovl2 on sex differences in n-3 PUFA levels.

Dyadic inter-group cooperation in shotgun hunting activities in a Congo Basin village.

Understanding the dynamics of inter-group cooperation in human adaptation has been the subject of recent empirical and theoretical studies in evolutionary anthropology, beginning to fill gaps in our knowledge of how interactions across political, economic and social domains can - and often do - lead to stable, large-scale cooperation. Here we investigate dyadic intergroup cooperation in shotgun hunting in the Republic of the Congo. In the Congo Basin, inter-group cooperation between foragers and farmers is at the centre of an exchange system maintained by traditional norms and institutions such as fictive kinship. Here, we focused on what factors predict cooperative shotgun hunting exchanges between BaYaka and Yambe. We conducted structured interviews with 48 BaYaka hunters and 18 Yambe men who organise hunts in a village along the Motaba River. We used Bayesian multilevel regression models to investigate the influence of Yambe and BaYaka attributes on probability of dyadic cooperation. We found that BaYaka men's reputations as skilled hunters and their family size each predicted cooperation in shotgun hunting, whereas there was no effect of Yambe attributes (status, wealth, family size). We discuss the results in terms of evolutionary models of men as hunters and inter-group cooperation, as well as biodiversity conservation implications.

Implementing evidence-based assertions of clinical actionability in the context of secondary findings: Updates from the ClinGen Actionability Working Group.

PURPOSE: The ClinGen Actionability Working Group (AWG) developed an evidence-based framework to generate actionability reports and scores of gene-condition pairs in the context of secondary findings from genome sequencing. Here we describe the expansion of the framework to include actionability assertions. METHODS: Initial development of the actionability rubric was based on previously scored adult gene-condition pairs and individual expert evaluation. Rubric refinement was iterative and based on evaluation, feedback, and discussion. The final rubric was pragmatically evaluated via integration into actionability assessments for 27 gene-condition pairs. RESULTS: The resulting rubric has a 4-point scale (limited, moderate, strong, and definitive) and uses the highest-scoring outcome-intervention pair of each gene-condition pair to generate a preliminary assertion. During AWG discussions, predefined criteria and factors guide discussion to produce a consensus assertion for a gene-condition pair, which may differ from the preliminary assertion. The AWG has retrospectively generated assertions for all previously scored gene-condition pairs and are prospectively asserting on gene-condition pairs under assessment, having completed over 170 adult and 188 pediatric gene-condition pairs. CONCLUSION: The AWG expanded its framework to provide actionability assertions to enhance the clinical value of their resources and increase their utility as decision aids regarding return of secondary findings.

Outcomes following a false positive multi-cancer early detection (MCED) test: Results from DETECT-A, the first large, prospective, interventional MCED study.

Guideline recommended standard of care (SoC) screening is available for four cancer types; most cancer-related deaths are caused by cancers without SoC screening. DETECT-A is the first prospective interventional trial evaluating an MCED blood test (CancerSEEK) in women without a history of cancer, providing the first opportunity to assess the long-term outcomes of individuals with false positive (FP) MCED results. This prospective analysis of DETECT-A participants with FP results evaluates the performance of an imaging-based diagnostic workflow and examines cancer risk following a FP result. This analysis included all DETECT-A participants with a positive CancerSEEK test and subsequent flourine-18 fluorodeoxyglucose positron emission tomography-IV contrast enhanced computed tomography (18-F-FDG PET-CT) imaging and clinical workup indicating no evidence of cancer within one year of enrollment (n=98). Medical records, study interactions, and study surveys were used to assess cancer incidence, treatments, and clinical outcomes through August 2023. Ninety-five of 98 participants with a FP result remained cancer-free with a median follow-up of 3.6 years (IQR: 2.5-4.1) from determination of FP status. Three incident cancers were observed over the follow-up period. One bilateral stage IIIC ovarian cancer was diagnosed 1.9 years after determination of FP status; two stage I breast cancers were diagnosed 0.1 and 1.6 years from determination of FP status. The annual incidence rate of cancer during follow-up from FP determination was 1.0% (95% CI: 0.2%-2.8%). Participants with a positive CancerSEEK test who underwent 18-F-FDG PET-CT and clinical workup without cancer findings had low risk for cancer over the following several years.

Rethinking eco-evo studies of gene expression for non-model organisms in the genomic era.

Recent advances in genomic technology, including the rapid development of long-read sequencing technology and single-cell RNA-sequencing methods, are poised to significantly expand the kinds of studies that are feasible in ecological genomics. In this perspective, we review these new technologies and discuss their potential impact on gene expression studies in non-model organisms. Although traditional RNA-sequencing methods have been an extraordinarily powerful tool to apply functional genomics in an ecological context, bulk RNA-seq approaches often rely on de novo transcriptome assembly, and cannot capture expression changes in rare cell populations or distinguish shifts in cell type abundance. Advancements in genome assembly technology, particularly long-read sequencing, and improvements in the scalability of single-cell RNA-sequencing (scRNA-seq) offer unprecedented resolution in understanding cellular heterogeneity and gene regulation. We discuss the potential of these technologies to enable disentangling differential gene regulation from cell type composition differences and uncovering subtle expression patterns masked by bulk RNA-seq. The integration of these approaches provides a more nuanced understanding of the ecological and evolutionary dynamics of gene expression, paving the way for refined models and deeper insights into the generation of biodiversity.

Multi-year clinical outcomes of cancers diagnosed following detection by a blood-based multi-cancer early detection (MCED) test.

In the U.S., <20% of cancers are diagnosed by standard-of-care (SoC) screening. Multi-cancer early detection (MCED) tests offer the opportunity to expand cancer screening. Understanding the characteristics and clinical outcomes of MCED-detected cancers is critical to clarifying MCED tests' potential impact. DETECT-A is the first prospective interventional trial of an MCED blood test (CancerSEEK). CancerSEEK, coupled with diagnostic PET-CT, identified cancers including those not detected by SoC screening, the majority of which were localized or regional. We report multi-year outcomes in patients with cancers diagnosed following a positive CancerSEEK test. Nine cancer types were diagnosed in 26 participants whose cancers were first detected by CancerSEEK. Information on cancer diagnoses, treatments, and clinical outcomes was extracted from medical records through November 2022. Data collection occurred a median of 4.4 years (IQR: 4.1-4.6) following study enrollment. Thirteen of 26 (50%) participants were alive and cancer-free [ovarian (4), thyroid (1), uterine (2), breast (1), colorectal (2), and lung (3)]; 7/13 (54%) had cancers without recommended SoC screening modalities. All 8 treated stage I or II participants (8/8, 100%) and 12/14 (86%) surgically-treated participants were alive and cancer-free. Eligibility for surgical treatment was associated with favorable multi-year outcomes (p = 0.0002). Half of participants with MCED-detected cancers were alive and cancer-free after 4.4 years median follow-up. Most were diagnosed with early-stage cancers and were treated surgically. These results suggest that early cancer detection by CancerSEEK may have facilitated curative-intent treatments and associated positive clinical outcomes in some DETECT-A participants.

Topical Calcipotriol Plus 5-Fluorouracil in the Treatment of Actinic Keratosis, Bowen's Disease, and Squamous Cell Carcinoma: A Systematic Review.

BACKGROUND/OBJECTIVES: Actinic keratoses (AK) are premalignant skin lesions caused by chronic sun exposure, topically managed by 5-fluorouracil (5-FU), diclofenac 3% gel, and imiquimod. Despite their effectiveness, long treatment duration and severe adverse local skin reactions have limited patient concordance. Calcipotriol has recently been used as a combination agent for existing topical AK treatments. A systematic review was performed to determine the clinical efficacy of 5-FU and calcipotriol for the treatment of AK, Bowen's disease, and squamous cell carcinoma (SCC). METHODS: A systematic literature search was conducted on Medline, Embase, and Cochrane Library. Among the 84 records screened, 12 were retrieved for full-text review and 8 were included in the final analysis. RESULTS: Among the 8 studies, there were 214 control patients and 288 patients who received the intervention. The combination 5% 5-FU with calcipotriol resulted in a significant reduction in the number of AKs on the face, scalp, right upper extremity, and left upper extremity for all sites at 8 weeks (P < .0001). No significant difference in SCC incidence was observed at 1 or 2 years, but there was a significant reduction observed at 3 years for SCC on face and scalp. No study assessed the combination for Bowen's disease. CONCLUSIONS: Combination 5% 5-FU with calcipotriol is an effective treatment for Aks; however, future trials may consider longer treatment and follow-up periods for the treatment and prevention of AK, SCC in situ, and SCC.

Effect of Immunosuppression on the Immune Response to SARS-CoV-2 Infection and Vaccination.

Immunosuppressive treatment in patients with rheumatic diseases can maintain disease remission but also increase risk of infection. Their response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is frequently blunted. In this study we evaluated the effect of immunosuppression exposure on humoral and T cell immune responses to SARS-CoV-2 infection and vaccination in two distinct cohorts of patients; one during acute SARS-CoV-2 infection and 3 months later during convalescence, and another prior to SARS-CoV-2 vaccination, with follow up sampling 6 weeks after vaccination. Results were compared between rituximab-exposed (in previous 6 months), immunosuppression-exposed (in previous 3 months), and non-immunosuppressed groups. The immune cell phenotype was defined by flow cytometry and ELISA. Antigen specific T cell responses were estimated using a whole blood stimulation interferon-γ release assay. A focused post-vaccine assessment of rituximab-treated patients using high dimensional spectral cytometry was conducted. Acute SARS-CoV-2 infection was characterised by T cell lymphopenia, and a reduction in NK cells and naïve CD4 and CD8 cells, without any significant differences between immunosuppressed and non-immunosuppressed patient groups. Conversely, activated CD4 and CD8 cell counts increased in non-immunosuppressed patients with acute SARS-CoV-2 infection but this response was blunted in the presence of immunosuppression. In rituximab-treated patients, antigen-specific T cell responses were preserved in SARS-CoV-2 vaccination, but patients were unable to mount an appropriate humoral response.

Obesity.

Obesity is a common condition and a major cause of morbidity and mortality. Fortunately, weight loss treatment can reduce obesity-related complications. This review summarizes the evidence-based strategies physicians can employ to identify, prevent, and treat obesity, including best practices to diagnose and counsel patients, to assess and address the burden of weight-related disease including weight stigma, to address secondary causes of weight gain, and to help patients set individualized and realistic weight loss goals and an effective treatment plan. Effective treatments include lifestyle modification and adjunctive therapies such as antiobesity medications and metabolic and bariatric surgery.

Dietary docosahexaenoic acid (DHA) downregulates liver DHA synthesis by inhibiting eicosapentaenoic acid elongation.

DHA is abundant in the brain where it regulates cell survival, neurogenesis, and neuroinflammation. DHA can be obtained from the diet or synthesized from alpha-linolenic acid (ALA; 18:3n-3) via a series of desaturation and elongation reactions occurring in the liver. Tracer studies suggest that dietary DHA can downregulate its own synthesis, but the mechanism remains undetermined and is the primary objective of this manuscript. First, we show by tracing 13C content (δ13C) of DHA via compound-specific isotope analysis, that following low dietary DHA, the brain receives DHA synthesized from ALA. We then show that dietary DHA increases mouse liver and serum EPA, which is dependant on ALA. Furthermore, by compound-specific isotope analysis we demonstrate that the source of increased EPA is slowed EPA metabolism, not increased DHA retroconversion as previously assumed. DHA feeding alone or with ALA lowered liver elongation of very long chain (ELOVL2, EPA elongation) enzyme activity despite no change in protein content. To further evaluate the role of ELOVL2, a liver-specific Elovl2 KO was generated showing that DHA feeding in the presence or absence of a functional liver ELOVL2 yields similar results. An enzyme competition assay for EPA elongation suggests both uncompetitive and noncompetitive inhibition by DHA depending on DHA levels. To translate our findings, we show that DHA supplementation in men and women increases EPA levels in a manner dependent on a SNP (rs953413) in the ELOVL2 gene. In conclusion, we identify a novel feedback inhibition pathway where dietary DHA downregulates its liver synthesis by inhibiting EPA elongation.