A Blinded Crossover Study Design to Evaluate Midazolam as an Adjunct for Equine Standing Sedation for Routine Oral Examinations.

This study aimed to evaluate the effects of including midazolam to a common equine standing sedation protocol for routine oral examination. Twelve horses underwent two examinations at least seven days apart. Horses were randomly assigned to receive midazolam intravenously (IV) (0.02mg/kg) or a placebo injection of saline (2-2.5mL IV). Five minutes later, detomidine (0.01mg/kg) and butorphanol (0.01mg/kg) were administered IV and horses were placed in standing stocks. A veterinarian blinded to the treatment protocol used a descriptive scoring system to assess degree of ataxia, acceptance of speculum, chewing on the speculum, headshaking, tongue movement, resistance to palpation, and eye appearance as related to the grimace score. During each examination, additional sedation of IV detomidine (0.006mg/kg) and butorphanol (0.006mg/kg) was administered at the discretion of the blinded practitioner to facilitate safe examination. At the second examination horses received the opposite treatment protocol and, following examination, a routine occlusal adjustment. Scores were compared using JMP software with a repeated measures mixed effects model, treatment as a fixed effect and horse and horse/treatment interaction as random effects. Significance was set at P<0.05. There were no significant differences in any of the single or overall sedation scores between treatment groups or within individual horses (P=0.3). Trends towards improvement of some assessed characteristics of sedation, including decreased tongue movement and less resistance to acceptance of speculum were observed. The use of midazolam may prove beneficial for routine oral examination, as well as other standing procedures, with no obvious undesired side effects.

Single-cell detection of copy number changes reveals dynamic mechanisms of adaptation to antifungals in Candida albicans.

Genomic copy number changes are associated with antifungal drug resistance and virulence across diverse fungal pathogens, but the rate and dynamics of these genomic changes in the presence of antifungal drugs are unknown. Here we optimized a dual-fluorescent reporter system in the diploid pathogen Candida albicans to quantify haplotype-specific copy number variation (CNV) and loss of heterozygosity (LOH) at the single-cell level with flow cytometry. We followed the frequency and dynamics of CNV and LOH at two distinct genomic locations in the presence and absence of antifungal drugs in vitro and in a murine model of candidiasis. Copy number changes were rapid and dynamic during adaptation to fluconazole and frequently involved competing subpopulations with distinct genotypes. This study provides quantitative evidence for the rapid speed at which diverse genotypes arise and undergo dynamic population-level fluctuations during adaptation to antifungal drugs in vitro and in vivo.

Overcoming immune evasion from post-translational modification of a mutant KRAS epitope to achieve TCR-engineered T cell-mediated antitumor activity.

T cell receptor (TCR)-T cell immunotherapy, in which T cells are engineered to express a TCR specific for a tumor epitope, is a form of adoptive cell therapy (ACT) that has demonstrated promise against various tumor types. Mutants of oncoprotein KRAS, particularly at glycine-12 (G12), are frequent drivers of tumorigenicity, but also attractive targets for TCR-T cell therapy. However, MHC class I-restricted TCRs specifically targeting G12-mutant KRAS epitopes in the context of tumors expressing HLA-A2, the most common human HLA-A allele, have remained elusive despite evidence that an epitope encompassing the mutation can bind HLA-A2 and induce T cell responses. We report that post-translational modifications of the protein on this epitope may allow tumor cells to evade immunologic pressure from TCR-T cells. A lysine side chain-methylated KRAS G12V peptide, rather than unmodified epitope, may be presented in HLA-A2 by tumor cells and impact recognition by TCRs. Using a novel computationally guided approach to design TCRs, we developed by mutagenesis TCRs that recognize this methylated peptide, enhancing tumor recognition and destruction. Additionally, we identified TCRs with similar functional activity in normal repertoires from rare primary T cells by stimulation with modified peptide, clonal expansion, and selection. Mechanistically, a gene knockout screen to identify mechanism(s) by which tumor cells methylate or demethylate this epitope unveiled SPT6 as a demethylating protein that could be targeted to improve effectiveness of these TCRs. These findings highlight the role of post-translational modifications in immune evasion and suggest that identifying and targeting such modifications should facilitate development of more effective TCR-T cell therapies.

Association of Limited Health Literacy With Clinical and Patient-Reported Outcomes in Individuals With Systemic Lupus Erythematosus.

OBJECTIVE: Health literacy is an important social determinant of health, with limited health literacy associated with worse health outcomes. This study examined the associations between limited health literacy with patient-reported outcomes and disease activity/damage among 267 Black women with active systemic lupus erythematosus (SLE) enrolled in the Peer Approaches to Lupus Self-Management (PALS) program. METHODS: The three-item Chew Health Literacy Screening was used to dichotomize those reporting in the "limited" range on any item with outcomes compared via generalized linear models. Baseline surveys and assessments obtained at study entry as part of the PALS study were used. Primary outcomes included disease activity and lupus damage; other secondary outcomes included patient activation, self-efficacy, physician/patient communication, and quality of life. RESULTS: The study included 267 Black women with SLE. In covariate-adjusted analyses, participants with limited health literacy (88 [33%]) were more likely to have lower patient activation (Patient Activation Measure P < 0.0001), lower self-efficacy (Lupus Self-Efficacy P < 0.0001), higher lupus damage (self-administered Brief Index of Lupus Damage P = .016), higher disease activity (Systemic Lupus Activity Questionnaire symptom severity P = 0.006), and worse physician/patient communication (patient-centered care P < 0.0001) compared to those with adequate health literacy. Those with limited health literacy also reported worse lupus quality of life (P = 0.0004) and greater levels of stress (Perceived Stress Scale-4 P < 0.0001) and were 2.4 times more likely to have probable major depression (Patient Health Questionnaire Depression Scale-8 of ≥10 P = 0.004) and probable anxiety disorder (General Anxiety Disorder-7 of ≥10 P = 0.007) compared to those with adequate health literacy. CONCLUSION: Black women with SLE and limited health literacy have worse clinical outcomes and represent a particularly vulnerable population with significantly disparate health outcomes. These findings suggest health literacy and complexities of managing SLE may impair clinical care in multiple domains, ultimately contributing to higher disease activity and death/damage, and are important to address in clinical care and future interventions in patients with SLE.

A national education program for rapid genomics in pediatric acute care: Building workforce confidence, competence, and capability.

PURPOSE: To develop and evaluate a scalable national program to build confidence, competence and capability in the use of rapid genomic testing (rGT) in the acute pediatric setting. METHODS: We used theory-informed approaches to design a modular, adaptive program of blended learning aimed at diverse professional groups involved in acute pediatric care. The program comprised 4 online learning modules and an online workshop and was centered on case-based learning. We evaluated the program using the Kirkpatrick 4-level model of training evaluation and report our findings using the Reporting Item Standards for Education and its Evaluation (RISE2) guidelines for genomics education and evaluation. RESULTS: Two hundred and two participants engaged with at least 1 component of the program. Participants self-reported increased confidence in using rGT, (P < .001), and quiz responses objectively demonstrated increased competence (eg, correct responses to a question on pretest counseling increased from 30% to 64%; P < .001). Additionally, their capability in applying genomic principles to simulated clinical cases increased (P < .001), as did their desire to take on more responsibility for performing rGT. The clinical interpretation of more complex test results (such as negative results or variants of uncertain significance) appeared to be more challenging, indicating a need for targeted education in this area. CONCLUSION: The program format was effective in delivering multidisciplinary and wide-scale genomics education in the acute care context. The modular approach we have developed now lends itself to application in other medical specialties or areas of health care.

Post-Transplant Lymphoproliferative Disorder Presenting as a Gastrointestinal Fistulous Tract in a Heart Transplant Recipient: Case Report and Literature Review.

We present a challenging case of Epstein-Barr virus-related isolated small bowel post-transplant lymphoproliferative disorder (PTLD) in a pediatric heart transplant recipient presenting as recurrent gastrointestinal (GI) bleeding and subsequently a GI fistulous tract with associated intra-abdominal abscess. Diagnosis was not confirmed until exploratory laparoscopy was performed, with excision of the fistulous tract revealing evidence of PTLD on pathology. Early diagnosis of GI-PTLD remains a challenge, especially if isolated in the small intestine. Diagnosis may rely on positron emission tomography/ computed tomography scan (PET/CT) or invasive intervention to obtain appropriate tissue samples for pathology diagnosis.

How students taking introductory biology experience the chemistry content.

Student experiences learning chemistry have been well studied in chemistry courses but less so in biology courses. Chemistry concepts are foundational to introductory biology courses, and student experiences learning chemistry concepts may impact their overall course experiences and subsequent student outcomes. In this study, we asked undergraduate students enrolled in introductory biology courses at a public R1 institution an open-response question asking how their experiences learning chemistry topics affected their identities as biologists. We used thematic analysis to identify common ideas in their responses. We found that while almost half of student respondents cited learning chemistry as having positive impacts on their experiences learning biology, students who struggled with chemistry topics were significantly more likely to have negative experiences learning biology. We also found significant relationships between prior chemistry preparation, student background, and the likelihood of students struggling with chemistry and negative experiences learning biology. These findings emphasize the impact of learning specific content on student psychosocial metrics and suggest areas for biology educators to focus on to support learning and alleviate student stress in introductory biology.

Carbonate chimneys at the highly productive point Dume methane seep: Fine-scale mineralogical, geochemical, and microbiological heterogeneity reflects dynamic and long-lived methane-metabolizing habitats.

Methane is a potent greenhouse gas that enters the marine system in large quantities at seafloor methane seeps. At a newly discovered seep site off the coast of Point Dume, CA, ~ meter-scale carbonate chimneys host microbial communities that exhibit the highest methane-oxidizing potential recorded to date. Here, we provide a detailed assessment of chimney geobiology through correlative mineralogical, geochemical, and microbiological studies of seven chimney samples in order to clarify the longevity and heterogeneity of these highly productive systems. U-Th dating indicated that a methane-driven carbonate precipitating system at Point Dume has existed for ~20 Kyr, while millimeter-scale variations in carbon and calcium isotopic values, elemental abundances, and carbonate polymorphs revealed changes in carbon source, precipitation rates, and diagenetic processes throughout the chimneys' lifespan. Microbial community analyses revealed diverse modern communities with prominent anaerobic methanotrophs, sulfate-reducing bacteria, and Anaerolineaceae; communities were more similar within a given chimney wall transect than in similar horizons of distinct structures. The chimneys represent long-lived repositories of methane-oxidizing communities and provide a window into how carbon can be transformed, sequestered, and altered over millennia at the Point Dume methane seep.

Ablation of Intestinal Epithelial Sialylation Predisposes to Acute and Chronic Intestinal Inflammation in Mice.

BACKGROUND & AIMS: Addition of sialic acids (sialylation) to glycoconjugates is a common capping step of glycosylation. Our study aims to determine the roles of the overall sialylation in intestinal mucosal homeostasis. METHODS: Mice with constitutive deletion of intestinal epithelial sialylation (IEC Slc35a1-/- mice) and mice with inducible deletion of sialylation in intestinal epithelium (TM-IEC Slc35a1-/- mice) were generated, which were used to determine the roles of overall sialylation in intestinal mucosal homeostasis by ex vivo and mutiomics studies. RESULTS: IEC Slc35a1-/- mice developed mild spontaneous microbiota-dependent colitis. Additionally, 30% of IEC Slc35a1-/- mice had spontaneous tumors in the rectum greater than the age of 12 months. TM-IEC Slc35a1-/- mice were highly susceptible to acute inflammation induced by 1% dextran sulfate sodium versus control animals. Loss of total sialylation was associated with reduced mucus thickness on fecal sections and within colon tissues. TM-IEC Slc35a1-/- mice showed altered microbiota with an increase in Clostridia disporicum, which is associated a global reduction in the abundance of at least 20 unique taxa; however, metabolomic analysis did not show any significant differences in short-chain fatty acid levels. Treatment with 5-fluorouracil led to more severe small intestine mucositis in the IEC Slc35a1-/- mice versus wild-type littermates, which was associated with reduced Lgr5+ cell representation in small intestinal crypts in IEC Slc35a1-/-;Lgr5-GFP mice. CONCLUSIONS: Loss of overall sialylation impairs mucus stability and the stem cell niche leading to microbiota-dependent spontaneous colitis and tumorigenesis.

Unmutated RRAS2 emerges as a key oncogene in post-partum-associated triple negative breast cancer.

BACKGROUND: Breast cancer (BC) is the most common cancer in women, with triple negative BC (TNBC) accounting for 20% of cases. While early detection and targeted therapies have improved overall life expectancy, TNBC remains resistant to current treatments. Although parity reduces the lifetime risk of developing BC, pregnancy increases the risk of developing TNBC for years after childbirth. Although numerous gene mutations have been associated with BC, no single gene alteration has been identified as a universal driver. RRAS2 is a RAS-related GTPase rarely found mutated in cancer. METHODS: Conditional knock-in mice were generated to overexpress wild type human RRAS2 in mammary epithelial cells. A human sample cohort was analyzed by RT-qPCR to measure RRAS2 transcriptional expression and to determine the frequency of both a single-nucleotide polymorphism (SNP rs8570) in the 3'UTR region of RRAS2 and of genomic DNA amplification in tumoral and non-tumoral human BC samples. RESULTS: Here we show that overexpression of wild-type RRAS2 in mice is sufficient to develop TNBC in 100% of females in a pregnancy-dependent manner. In human BC, wild-type RRAS2 is overexpressed in 68% of tumors across grade, location, and molecular type, surpassing the prevalence of any previously implicated alteration. Still, RRAS2 overexpression is notably higher and more frequent in TNBC and young parous patients. The increased prevalence of the alternate C allele at the SNP position in tumor samples, along with frequent RRAS2 gene amplification in both tumors and blood of BC patients, suggests a cause-and-effect relationship between RRAS2 overexpression and breast cancer. CONCLUSIONS: Higher than normal expression of RRAS2 not bearing activating mutations is a key driver in the majority of breast cancers, especially those of the triple-negative type and those linked to pregnancy.

Improved resilience and proteostasis mediate longevity upon DAF-2 degradation in old age.

Little is known about the possibility of reversing age-related biological changes when they have already occurred. To explore this, we have characterized the effects of reducing insulin/IGF-1 signaling (IIS) during old age. Reduction of IIS throughout life slows age-related decline in diverse species, most strikingly in the nematode Caenorhabditis elegans. Here we show that even at advanced ages, auxin-induced degradation of DAF-2 in single tissues, including neurons and the intestine, is still able to markedly increase C. elegans lifespan. We describe how reversibility varies among senescent changes. While senescent pathologies that develop in mid-life were not reversed, there was a rejuvenation of the proteostasis network, manifesting as a restoration of the capacity to eliminate otherwise intractable protein aggregates that accumulate with age. Moreover, resistance to several stressors was restored. These results support several new conclusions. (1) Loss of resilience is not solely a consequence of pathologies that develop in earlier life. (2) Restoration of proteostasis and resilience by inhibiting IIS is a plausible cause of the increase in lifespan. And (3), most interestingly, some aspects of the age-related transition from resilience to frailty can be reversed to a certain extent. This raises the possibility that the effect of IIS and related pathways on resilience and frailty during aging in higher animals might possess some degree of reversibility.

The immunity gap in primates.

Vertebrates exhibit sexual dimorphism in response to infectious diseases and in morbidity and mortality rates to various pathogens. Females are generally more immunocompetent than males, despite their increased reproductive burden and the immunosuppressive effects of gestation. In addition, females generally have lower incidences of cancer compared to males; however, they have higher rates of autoimmune disorders. These sex differences may be a result of life history differences, sexual selection, genetics, and/or the physiological effects of hormones. As highly social mammals with complex life histories, primates offer a unique opportunity to investigate the evolution of enhanced female immunocompetence. This review aims to examine the evidence of this immunity gap, understand current hypotheses for its evolution, and explore the potential role of X chromosome specific genes and heterozygosity within this framework.

Long-Term Effect of Home Blood Pressure Self-Monitoring Plus Medication Self-Titration for Patients With Hypertension: A Secondary Analysis of the ADAMPA Randomized Clinical Trial.

Importance: Patient empowerment through pharmacologic self-management is a common strategy for some chronic diseases such as diabetes, but it is rarely used for controlling blood pressure (BP). Several trials have shown its potential for reducing BP in the short term, but evidence in the longer term is scarce. Objective: To evaluate the longer-term effectiveness of BP self-monitoring plus self-titration of antihypertensive medication vs usual care for patients with poorly controlled hypertension, with passive follow-up and primary-care nursing involvement. Design, Setting, and Participants: The ADAMPA (Impact of Self-Monitoring of Blood Pressure and Self-Titration of Medication in the Control of Hypertension) study was a randomized, unblinded clinical trial with 2 parallel arms conducted in Valencia, Spain. Included participants were patients 40 years or older, with systolic BP (SBP) over 145 mm Hg and/or diastolic BP (DBP) over 90 mm Hg, recruited from July 21, 2017, to June 30, 2018 (study completion, August 25, 2020). Statistical analysis was conducted on an intention-to-treat basis from August 2022 to February 2024. Interventions: Participants were randomized 1:1 to usual care vs an individualized, prearranged plan based on BP self-monitoring plus medication self-titration. Main Outcomes and Measures: The main outome was the adjusted mean difference (AMD) in SBP between groups at 24 months of follow-up. Secondary outcomes were the AMD in DBP between groups at 24 months of follow-up, proportion of patients reaching the BP target (SBP <140 mm Hg and DBP <90 mm Hg), change in behaviors, quality of life, health service use, and adverse events. Results: Among 312 patients included in main trial, data on BP measurements at 24 months were available for 219 patients (111 in the intervention group and 108 in the control group). The mean (SD) age was 64.3 (10.1) years, and 120 patients (54.8%) were female; the mean (SD) SBP was 155.6 (13.1) mm Hg, and the mean (SD) diastolic BP was 90.8 (7.7) mm Hg. The median follow-up was 23.8 months (IQR, 19.8-24.5 months). The AMD in SBP at the end of follow-up was -3.4 mm Hg (95% CI, -4.7 to -2.1 mm Hg; P < .001), and the AMD in DBP was -2.5 mm Hg (95% CI, -3.5 to -1.6 mm Hg; P < .001). Subgroup analysis for the main outcome showed consistent results. Sensitivity analyses confirmed the robustness of the main findings. No differences were observed between groups in behaviors, quality of life, use of health services, or adverse events. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, BP self-monitoring plus self-titration of antihypertensive medication based on an individualized prearranged plan used in primary care reduced BP in the longer term with passive follow-up compared with usual care, without increasing health care use or adverse events. These results suggest that simple, inexpensive, and easy-to-implement self-management interventions have the potential to improve the long-term control of hypertension in routine clinical practice. Trial Registration: ClinicalTrials.gov Identifier: NCT03242785.

Engineered reactivity of a bacterial E1-like enzyme enables ATP-driven modification of protein C termini.

In biological systems, ATP provides an energetic driving force for peptide bond formation, but protein chemists lack tools that emulate this strategy. Inspired by the eukaryotic ubiquitination cascade, we developed an ATP-driven platform for C-terminal activation and peptide ligation based on E. coli MccB, a bacterial ancestor of ubiquitin-activating (E1) enzymes that natively catalyzes C-terminal phosphoramidate bond formation. We show that MccB can act on non-native substrates to generate an O-AMPylated electrophile that can react with exogenous nucleophiles to form diverse C-terminal functional groups including thioesters, a versatile class of biological intermediates that have been exploited for protein semisynthesis. To direct this activity towards specific proteins of interest, we developed the Thioesterification C-terminal Handle (TeCH)-tag, a sequence that enables high-yield, ATP-driven protein bioconjugation via a thioester intermediate. By mining the natural diversity of the MccB family, we developed two additional MccB/TeCH-tag pairs that are mutually orthogonal to each other and to the E. coli system, facilitating the synthesis of more complex bioconjugates. Our method mimics the chemical logic of peptide bond synthesis that is widespread in biology for high-yield in vitro manipulation of protein structure with molecular precision.

A common multi-host parasite shows genetic structuring at the host species and population levels.

Although individual parasite species commonly infect many populations across physical space as well as multiple host species, the extent to which parasites traverse physical and phylogenetic distances is unclear. Population genetic analyses of parasite populations can reveal how parasites move across space or between host species, including helping assess whether a parasite is more likely to infect a different host species in the same location or the same host species in a different location. Identifying these transmission barriers could be exploited for effective disease control. Here, we analysed population genetic structuring of the parasite Pasteuria ramosa in daphniid host species from different lakes. Outbreaks occurred most often in the common host species Daphnia dentifera and Daphnia retrocurva. The genetic distance between parasite samples tended to be smaller when samples were collected from the same lake, the same host species and closer in time. Within lakes, the parasite showed structure by host species and sampling date; within a host species, the parasite showed structure by lake and sampling date. However, despite this structuring, we found the same parasite genotype infecting closely related host species, and we sometimes found the same genotype in nearby lakes. Thus, P. ramosa experiences challenges infecting different host species and moving between populations, but doing so is possible. In addition, the structuring by sampling date indicates potential adaptation to or coevolution with host populations and supports prior findings that parasite population structure is dynamic during outbreaks.

The influence of internal pressure and neuromuscular agents on C. elegans biomechanics: an empirical and multi-compartmental in silico modelling study.

The function of a specific tissue and its biomechanics are interdependent, with pathologies or ageing often being intertwined with structural decline. The biomechanics of Caenorhabditis elegans, a model organism widely used in pharmacological and ageing research, has been established as biomarker for healthy ageing. However, the properties of the constituent tissues, and their contribution to the overall mechanical characteristics of the organism, remain relatively unknown. In this study we investigated the biomechanics of healthy C. elegans cuticle, muscle tissue, and pseudocoelom using a combination of indentation experiments and in silico modelling. We performed stiffness measurements using an atomic force microscope. To approximate the nematode's cylindrical body we used a novel three-compartment nonlinear finite element model, enabling us to analyse of how changes in the elasticity of individual compartments affect the bulk stiffness. We then fine-tuned the parameters of the model to match the simulation force-indentation output to the experimental data. To test the finite element model, we modified distinct compartments experimentally. Our in silico results, in agreement with previous studies, suggest that hyperosmotic shock reduces stiffness by decreasing the internal pressure. Unexpectedly, treatment with the neuromuscular agent aldicarb, traditionally associated with muscle contraction, reduced stiffness by decreasing the internal pressure. Furthermore, our finite element model can offer insights into how drugs, mutations, or processes such as ageing target individual tissues.

Medium and Long-Term Weight Loss After Revisional Bariatric Surgery: A Systematic Review and Meta-Analysis.

Despite the current increase in revisional bariatric surgery (RBS), data on the sustainability of weight loss remain unclear. A systematic review and meta-analysis were performed to assess weight loss outcomes in adult patients undergoing RBS with follow-up > 2 years. Twenty-eight observational studies (n = 2213 patients) were included. The %TWL was 27.2 (95%CI = 23.7 to 30.6), and there was a drop in BMI of 10.2 kg/m2 (95%CI = - 11.6 to - 8.7). The %EWL was 54.8 (95%CI = 47.2 to 62.4) but with a high risk of publication bias (Egger's test = 0.003). The overall quality of evidence was very low. Our data reinforce that current evidence on RBS is mainly based on low-quality observational studies, and further higher-quality studies are needed to support evidence-based practice.

Comparison of the oncolytic activity of a replication-competent and a replication-deficient herpes simplex virus 1.

In 2015, the oncolytic herpes simplex virus 1 (HSV-1) T-VEC (talimogene laherparepvec) was approved for intratumoral injection in non-resectable malignant melanoma. To determine whether viral replication is required for oncolytic activity, we compared replication-deficient HSV-1 d106S with replication-competent T-VEC. High infectious doses of HSV-1 d106S killed melanoma (n = 10), head-and-neck squamous cell carcinoma (n = 11), and chondrosarcoma cell lines (n = 2) significantly faster than T-VEC as measured by MTT metabolic activity, while low doses of T-VEC were more effective over time. HSV-1 d106S and, to a lesser extent T-VEC, triggered caspase-dependent early apoptosis as shown by pan-caspase inhibition and specific induction of caspases 3/7, 8, and 9. HSV-1 d106S induced a higher ratio of apoptosis-inducing infected cell protein (ICP) 0 to apoptosis-blocking ICP6 than T-VEC. T-VEC was oncolytic for an extended period of time as viral replication continued, which could be partially blocked by the antiviral drug aciclovir. High doses of T-VEC, but not HSV-1 d106S, increased interferon-ß mRNA as part of the intrinsic immune response. When markers of immunogenic cell death were assessed, ATP was released more efficiently in the context of T-VEC than HSV-1 d106S infection, whereas HMGB1 was induced comparatively well. Overall, the early oncolytic effect on three different tumour entities was stronger with the non-replicative strain, while the replication-competent virus elicited a stronger innate immune response and more pronounced immunogenic cell death.

Intraoperative Evaluation of Breast Tissues During Breast Cancer Operations Using the MasSpec Pen.

Importance: Surgery with complete tumor resection remains the main treatment option for patients with breast cancer. Yet, current technologies are limited in providing accurate assessment of breast tissue in vivo, warranting development of new technologies for surgical guidance. Objective: To evaluate the performance of the MasSpec Pen for accurate intraoperative assessment of breast tissues and surgical margins based on metabolic and lipid information. Design, Setting, and Participants: In this diagnostic study conducted between February 23, 2017, and August 19, 2021, the mass spectrometry-based device was used to analyze healthy breast and invasive ductal carcinoma (IDC) banked tissue samples from adult patients undergoing breast surgery for ductal carcinomas or nonmalignant conditions. Fresh-frozen tissue samples and touch imprints were analyzed in a laboratory. Intraoperative in vivo and ex vivo breast tissue analyses were performed by surgical staff in operating rooms (ORs) within 2 different hospitals at the Texas Medical Center. Molecular data were used to build statistical classifiers. Main Outcomes and Measures: Prediction results of tissue analyses from classification models were compared with gross assessment, frozen section analysis, and/or final postoperative pathology to assess accuracy. Results: All data acquired from the 143 banked tissue samples, including 79 healthy breast and 64 IDC tissues, were included in the statistical analysis. Data presented rich molecular profiles of healthy and IDC banked tissue samples, with significant changes in relative abundances observed for several metabolic species. Statistical classifiers yielded accuracies of 95.6%, 95.5%, and 90.6% for training, validation, and independent test sets, respectively. A total of 25 participants enrolled in the clinical, intraoperative study; all were female, and the median age was 58 years (IQR, 44-66 years). Intraoperative testing of the technology was successfully performed by surgical staff during 25 breast operations. Of 273 intraoperative analyses performed during 25 surgical cases, 147 analyses from 22 cases were subjected to statistical classification. Testing of the classifiers on 147 intraoperative mass spectra yielded 95.9% agreement with postoperative pathology results. Conclusions and Relevance: The findings of this diagnostic study suggest that the mass spectrometry-based system could be clinically valuable to surgeons and patients by enabling fast molecular-based intraoperative assessment of in vivo and ex vivo breast tissue samples and surgical margins.

Balance and imbalance in biogeochemical cycles reflect the operation of closed, exchange, and open sets.

Biogeochemical reactions modulate the chemical composition of the oceans and atmosphere, providing feedbacks that sustain planetary habitability over geological time. Here, we mathematically evaluate a suite of biogeochemical processes to identify combinations of reactions that stabilize atmospheric carbon dioxide by balancing fluxes of chemical species among the ocean, atmosphere, and geosphere. Unlike prior modeling efforts, this approach does not prescribe functional relationships between the rates of biogeochemical processes and environmental conditions. Our agnostic framework generates three types of stable reaction combinations: closed sets, where sources and sinks mutually cancel for all chemical reservoirs; exchange sets, where constant ocean-atmosphere conditions are maintained through the growth or destruction of crustal reservoirs; and open sets, where balance in alkalinity and carbon fluxes is accommodated by changes in other chemical components of seawater or the atmosphere. These three modes of operation have different characteristic timescales and may leave distinct evidence in the rock record. To provide a practical example of this theoretical framework, we applied the model to recast existing hypotheses for Cenozoic climate change based on feedbacks or shared forcing mechanisms. Overall, this work provides a systematic and simplified conceptual framework for understanding the function and evolution of global biogeochemical cycles.