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Summary: Background: Although immunomodulators have established benefit against the new coronavirus disease (COVID-19) in general, it is uncertain whether such agents improve outcomes without increasing the risk of secondary infections in the specific subgroup of previously immunocompromised patients. We assessed the effect of immunomodulators on outcomes of immunocompromised patients hospitalized for COVID-19. Methods: The protocol was prospectively registered with PROSPERO (CRD42022335397). MEDLINE, Cochrane Central Register of Controlled Trials and references of relevant articles were searched up to 01-06-2022. Authors of potentially eligible randomized controlled trials were contacted to provide data on immunocompromised patients randomized to immunomodulators vs control (i.e., placebo or standard-of-care). Findings: Eleven randomized controlled trials involving 397 immunocompromised patients hospitalized for COVID-19 were included. Ten trials had low risk of bias. There was no difference between immunocompromised patients randomized to immunomodulators vs control regarding mortality [30/182 (16.5%) vs 41/215 (19.1%); RR 0.93, 95% CI 0.61–1.41; p = 0.74], secondary infections (RR 1.00, 95% CI 0.64–1.58; p = 0.99) and change in World Health Organization ordinal scale from baseline to day 15 (weighed mean difference 0.27, 95% CI -0.09–0.63; p = 0.15). In subgroup analyses including only patients with hematologic malignancy, only trials with low risk of bias, only trials administering IL-6 inhibitors, or only trials administering immunosuppressants, there was no difference between comparators regarding mortality. Interpretation: Immunomodulators, compared to control, were not associated with harmful or beneficial outcomes, including mortality, secondary infections, and change in ordinal scale, when administered to immunocompromised patients hospitalized for COVID-19. Funding: Hellenic Foundation for Research and Innovation.

ABSTRACT Inhalation of airborne conidia of the ubiquitous fungus Aspergillus fumigatus commonly occurs but invasive aspergillosis is rare except in profoundly immunocompromised persons. Severe influenza predisposes patients to invasive pulmonary aspergillosis by mechanisms that are poorly defined. Using a post-influenza aspergillosis model, we found that superinfected mice had 100% mortality when challenged with A. fumigatus conidia on days 2 and 5 (early stages) of influenza A virus infection but 100% survival when challenged on days 8 and 14 (late stages). Influenza-infected mice superinfected with A. fumigatus had increased levels of the pro-inflammatory cytokines and chemokines interleukin (IL)-6, tumor necrosis factor (TNF)α, interferon (IFN)β, IL-12p70, IL-1α, IL-1β, CXC motif chemokine ligand 1 (CXCL1), granulocyte-colony-stimulating factor (G-CSF), macrophage inflammatory protein (MIP)-1α, MIP-1β, regulated upon activation, normal T cell expressed and presumably secreted (RANTES), and monocyte chemoattractant protein (MCP)-1. Surprisingly, on histopathological analysis, superinfected mice did not have greater lung inflammation compared with mice infected with influenza alone. Mice infected with influenza had dampened neutrophil recruitment to the lungs following subsequent challenge with A. fumigatus, but only if the fungal challenge was executed during the early stages of influenza infection. However, influenza infection did not have a major effect on neutrophil phagocytosis and killing of A. fumigatus conidia. Moreover, minimal germination of conidia was seen on histopathology even in the superinfected mice. Taken together, our data suggest that the high mortality rate seen in mice during the early stages of influenza-associated pulmonary aspergillosis is multifactorial with a greater contribution from dysregulated inflammation than microbial growth. IMPORTANCE Severe influenza is a risk factor for fatal invasive pulmonary aspergillosis; however, the mechanistic basis for the lethality is unclear. Utilizing an influenza-associated pulmonary aspergillosis (IAPA) model, we found that mice infected with influenza A virus followed by Aspergillus fumigatus had 100% mortality when superinfected during the early stages of influenza but survived at later stages. While superinfected mice had dysregulated pulmonary inflammatory responses compared to controls, they had neither increased inflammation nor extensive fungal growth. Although influenza-infected mice had dampened neutrophil recruitment to the lungs following subsequent challenge with A. fumigatus, influenza did not affect the ability of neutrophils to clear the fungi. Our data suggest that the lethality seen in our model of IAPA is multifactorial with dysregulated inflammation being a greater contributor than uncontrollable microbial growth. If confirmed in humans, our findings provide a rationale for clinical studies of adjuvant anti-inflammatory agents in the treatment of IAPA.

BACKGROUND Influenza A virus (IAV) and SARS-CoV-2 are pandemic viruses causing millions of deaths, yet their clinical manifestations are distinctly different.METHODS With the hypothesis that upper airway immune and epithelial cell responses are also distinct, we performed single-cell RNA sequencing (scRNA-Seq) on nasal wash cells freshly collected from adults with either acute COVID-19 or influenza or from healthy controls. We focused on major cell types and subtypes in a subset of donor samples.Results Nasal wash cells were enriched for macrophages and neutrophils for both individuals with influenza and those with COVID-19 compared with healthy controls. Hillock-like epithelial cells, M2-like macrophages, and age-dependent B cells were enriched in COVID-19 samples. A global decrease in IFN-associated transcripts in neutrophils, macrophages, and epithelial cells was apparent in COVID-19 samples compared with influenza samples. The innate immune response to SARS-CoV-2 appears to be maintained in macrophages, despite evidence for limited epithelial cell immune sensing. Cell-to-cell interaction analyses revealed a decrease in epithelial cell interactions in COVID-19 and highlighted differences in macrophage-macrophage interactions for COVID-19 and influenza.Conclusions Our study demonstrates that scRNA-Seq can define host and viral transcriptional activity at the site of infection and reveal distinct local epithelial and immune cell responses for COVID-19 and influenza that may contribute to their divergent disease courses.Funding Massachusetts Consortium on Pathogen Readiness, the Mathers Foundation, and the Department of Defense (W81XWH2110029) “COVID-19 Expansion for AIRe Program.”

Olfactory sensory neurons (OSNs) in vertebrates detect odorants using multiple cilia, which protrude from the end of the dendrite and require centrioles for their formation. In mouse olfactory epithelium, the centrioles originate in progenitor cells near the basal lamina, often 50–100 μm from the apical surface. It is unknown how centrioles traverse this distance or mature to form cilia. Using high-resolution expansion microscopy, we found that centrioles migrate together, with multiple centrioles per group and multiple groups per OSN, during dendrite outgrowth. Centrioles were found by live imaging to migrate slowly, with a maximum rate of 0.18 µm/minute. Centrioles in migrating groups were associated with microtubule nucleation factors, but acquired rootletin and appendages only in mature OSNs. The parental centriole had preexisting appendages, formed a single cilium before other centrioles, and retained its unique appendage configuration in the mature OSN. We developed an air-liquid interface explant culture system for OSNs and used it to show that centriole migration can be perturbed ex vivo by stabilizing microtubules. We consider these results in the context of a comprehensive model for centriole formation, migration, and maturation in this important sensory cell type.

Abstract Oral potentially malignant disorders (OPMDs) with genomic alterations have a heightened risk of evolving into oral squamous cell carcinoma (OSCC). Currently, genomic data are typically obtained through invasive tissue biopsy. However, brush biopsy is a non-invasive method that has been utilized for identifying dysplastic cells in OPMD but its effectiveness in reflecting the genomic landscape of OPMDs remains uncertain. This pilot study investigates the potential of brush biopsy samples in accurately reconstructing the genomic profile and tumor evolution in a patient with both OPMD and OSCC. We analyzed single nucleotide variants (SNVs), copy number aberrations (CNAs), and subclonal architectures in paired tissue and brush biopsy samples. The results showed that brush biopsy effectively captured 90% of SNVs and had similar CNA profiles as those seen in its paired tissue biopsies in all lesions. It was specific, as normal buccal mucosa did not share these genomic alterations. Interestingly, brush biopsy revealed shared SNVs and CNAs between the distinct OPMD and OSCC lesions from the same patient, indicating a common ancestral origin. Subclonal reconstruction confirmed this shared ancestry, followed by divergent evolution of the lesions. These findings highlight the potential of brush biopsies in accurately representing the genomic profile of OPL and OSCC, proving insight into reconstructing tumor evolution.

Background: Two-stage exchange arthroplasty remains the gold standard for treating chronic hip periprosthetic joint infections. However, controversy remains regarding the optimal spacer type, particularly among patients with increased dislocation risk. This study reports on the outcomes of articulating hip spacers utilizing a single constrained-liner design. Methods: All patients who underwent treatment for hip periprosthetic joint infection at a single institution were screened. Patients were included if they received an articulating spacer utilizing a constrained liner of a single manufacturer design. Indications for constrained liner, demographic variables, and surgical variables were recorded. Patients were assessed for dislocation and component loosening prior to the second stage or at the final follow-up if the second stage was not undertaken. Comparative analysis was performed. Results: Overall, 26 constrained liners were utilized in 25 patients. Indications for constrained liner included history of dislocation (n = 14), massive proximal femoral bone loss (n = 14), greater trochanteric deficiency (n = 12), and absent abductors (n = 7). Many patients had more than one indication. In total, 9 hips (34.6%) underwent a second stage at an average of 7.4 months, while 17 hips never underwent a second stage with an average follow-up of 27.6 months. One patient experienced failure of their constrained liner prior to the second stage due to pelvic discontinuity and massive acetabular bone loss. Conclusions: Utilization of a constrained liner as an articulating spacer is a viable option for patients at high risk of instability. Meticulous cement technique, appropriate component position, and implant selection are crucial in achieving successful outcomes.

The spindle assembly checkpoint (SAC) temporally regulates mitosis by preventing progression from metaphase to anaphase until all chromosomes are correctly attached to the mitotic spindle. Centrosomes refine the spatial organization of the mitotic spindle at the spindle poles. However, centrosome loss leads to elongated mitosis, suggesting that centrosomes also inform the temporal organization of mitosis in mammalian cells. Here, we find that the mitotic delay in acentrosomal cells is enforced by the SAC in a MPS1-dependent manner, and that a SAC-dependent mitotic delay is required for bipolar cell division to occur in acentrosomal cells. Although acentrosomal cells become polyploid, polyploidy is not sufficient to cause dependency on a SAC-mediated delay to complete cell division. Rather, the division failure in absence of MPS1 activity results from mitotic exit occurring before acentrosomal spindles can become bipolar. Furthermore, prevention of centrosome separation suffices to make cell division reliant on a SAC-dependent mitotic delay. Thus, centrosomes and their definition of two spindle poles early in mitosis provide a ‘timely two-ness’ that allows cell division to occur in absence of a SAC-dependent mitotic delay.

Abstract Background Small airways disease (SAD) is a major cause of airflow obstruction in COPD patients and has been identified as a precursor to emphysema. Although the amount of SAD in the lungs can be quantified using our Parametric Response Mapping (PRM) approach, the full breadth of this readout as a measure of emphysema and COPD progression has yet to be explored. We evaluated topological features of PRM-derived normal parenchyma and SAD as surrogates of emphysema and predictors of spirometric decline. Methods PRM metrics of normal lung (PRMNorm) and functional SAD (PRMfSAD) were generated from CT scans collected as part of the COPDGene study (n = 8956). Volume density (V) and Euler-Poincaré Characteristic (χ) image maps, measures of the extent and coalescence of pocket formations (i.e., topologies), respectively, were determined for both PRMNorm and PRMfSAD. Association with COPD severity, emphysema, and spirometric measures were assessed via multivariable regression models. Readouts were evaluated as inputs for predicting FEV1 decline using a machine learning model. Results Multivariable cross-sectional analysis of COPD subjects showed that V and χ measures for PRMfSAD and PRMNorm were independently associated with the amount of emphysema. Readouts χfSAD (β of 0.106, p

Background: Inpatient total hip arthroplasty (THA) and total knee arthroplasty (TKA) practices were dramatically affected in the United States in 2020 as elective surgeries were paused in response to the COVID-19 pandemic. This study sought to provide an updated estimate of inpatient total joint arthroplasty (TJA) case volumes in the United States in 2020. Methods: A retrospective cohort study was performed by identifying all adult patients who underwent primary, elective TJA from January 1st, 2017 to December 31st, 2020, using the National Inpatient Sample. Monthly and annual case volumes were reported with descriptive statistics. Baseline case volumes were established by taking the average number of monthly cases performed in 2017, 2018, and 2019. These monthly averages were compared to 2020 values. Results: From 2017 to 2019, the average case volume was 1,056,669 cases per year (41.0% THA, 59.0% TKA) and 88,055 cases per month. In 2020, 535,441 cases were identified (45.4% THA, 54.6% TKA), corresponding to a 49.3% reduction from the 2017-2019 annual average. Monthly cases decreased to 4515 in April during the “first wave” of COVID-19, corresponding to a 94.8% decrease from prior years. In June, cases rebounded to 55,520 before decreasing again in July to 50,100 during the “second wave” of COVID-19. During the “third wave,” COVID-19 cases decreased month-over-month from October through December (56.5% decrease). Conclusions: This updated estimate identified a 49.3% decrease in inpatient TJA cases in 2020 compared to prior years. This is similar to the 46.5-47.7% decrease in case volume previously reported.

Abstract Background Quantitative interstitial abnormalities (QIA) are an automated computed tomography (CT) finding of early parenchymal lung disease, associated with worse lung function, reduced exercise capacity, increased respiratory symptoms, and death. The metabolomic perturbations associated with QIA are not well known. We sought to identify plasma metabolites associated with QIA in smokers. We also sought to identify shared and differentiating metabolomics features between QIA and emphysema, another smoking-related advanced radiographic abnormality. Methods In 928 former and current smokers in the Genetic Epidemiology of COPD cohort, we measured QIA and emphysema using an automated local density histogram method and generated metabolite profiles from plasma samples using liquid chromatography–mass spectrometry (Metabolon). We assessed the associations between metabolite levels and QIA using multivariable linear regression models adjusted for age, sex, body mass index, smoking status, pack-years, and inhaled corticosteroid use, at a Benjamini–Hochberg False Discovery Rate p-value of ≤ 0.05. Using multinomial regression models adjusted for these covariates, we assessed the associations between metabolite levels and the following CT phenotypes: QIA-predominant, emphysema-predominant, combined-predominant, and neither- predominant. Pathway enrichment analyses were performed using MetaboAnalyst. Results We found 85 metabolites significantly associated with QIA, with overrepresentation of the nicotinate and nicotinamide, histidine, starch and sucrose, pyrimidine, phosphatidylcholine, lysophospholipid, and sphingomyelin pathways. These included metabolites involved in inflammation and immune response, extracellular matrix remodeling, surfactant, and muscle cachexia. There were 75 metabolites significantly different between QIA-predominant and emphysema-predominant phenotypes, with overrepresentation of the phosphatidylethanolamine, nicotinate and nicotinamide, aminoacyl-tRNA, arginine, proline, alanine, aspartate, and glutamate pathways. Conclusions Metabolomic correlates may lend insight to the biologic perturbations and pathways that underlie clinically meaningful quantitative CT measurements like QIA in smokers.

Abstract Pancreatic cancer is a highly aggressive cancer, and is primarily treated with gemcitabine, with increasing resistance. SIRT6 as a member of sirtuin family plays important roles in lifespan and diverse diseases, such as cancer, diabetes, inflammation and neurodegenerative diseases. Considering the role of SIRT6 in the cytoprotective effect, it might be a potential anticancer drug target, and is associated with resistance to anticancer therapy. However, very few SIRT6 inhibitors have been reported. Here, we reported the discovery of a pyrrole-pyridinimidazole derivative, 8a, as a new non-competitive SIRT6 inhibitor, and studied its roles and mechanisms in the antitumor activity and sensitization of pancreatic cancer to gemcitabine. Firstly, we found a potent SIRT6 inhibitor compound 8a by virtual screening and identified by molecular and cellular SIRT6 activity assays. 8a could effectively inhibit SIRT6 deacetylation activity with IC50 values of 7.46 ± 0.79 μM in FLUOR DE LYS assay, and 8a significantly increased the acetylation levels of H3 in cells. Then, we found that 8a could inhibit the cell proliferation and induce cell apoptosis in pancreatic cancer cells. We further demonstrate that 8a sensitize pancreatic cancer cells to gemcitabine via reversing the activation of PI3K/AKT/mTOR and ERK signaling pathways induced by gemcitabine and blocking the DNA damage repair pathway. Moreover, combination of 8a and gemcitabine induces cooperative antitumor activity in pancreatic cancer xenograft model in vivo. Overall, we demonstrate that 8a, a novel SIRT6 inhibitor, could be a promising potential drug candidate for pancreatic cancer treatment.

Aims: The modern prevalence of primary tumours causing metastatic bone disease is ill-defined in the oncological literature. Therefore, the purpose of this study is to identify the prevalence of primary tumours in the setting of metastatic bone disease, as well as reported rates of pathological fracture, postoperative complications, 90-day mortality, and 360-day mortality for each primary tumour subtype. Methods: The Premier Healthcare Database was queried to identify all patients who were diagnosed with metastatic bone disease from January 2015 to December 2020. The prevalence of all primary tumour subtypes was tabulated. Rates of long bone pathological fracture, 90-day mortality, and 360-day mortality following surgical treatment of pathological fracture were assessed for each primary tumour subtype. Patient characteristics and postoperative outcomes were analyzed based upon whether patients had impending fractures treated prophylactically versus treated completed fractures. Results: In total, 407,893 unique patients with metastatic bone disease were identified. Of the 14 primary tumours assessed, metastatic bone disease most frequently originated from lung (24.8%), prostatic (19.4%), breast (19.3%), gastrointestinal (9.4%), and urological (6.5%) malignancies. The top five malignant tumours resulting in long bone pathological fracture were renal (5.8%), myeloma (3.4%), female reproductive (3.2%), lung (2.8%), and breast (2.7%). Following treatment of pathological fractures of long bones, 90-day mortality rates were greatest for lung (12.1%), central nervous system (10.5%), lymphoma (10.4%), gastrointestinal (10.1%), and non-renal urinary (10.0%) malignancies. Finally, our study demonstrates improved 90-day and 360-day survival in patients treated for impending pathological fracture compared to completed fracture, as well as significantly lower rates of deep vein thrombosis, pulmonary embolism, urinary tract infection, and blood transfusion. Conclusion: This study defines the contemporary characteristics of primary malignancies resulting in metastatic bone disease. These data should be considered by surgeons when prognosticating patient outcomes during treatment of their metastatic bone disease. Cite this article: Bone Jt Open 2023;4(6):424–431.

Background: This study aims to compare indications, patient characteristics, hospital factors, and complication rates between total hip arthroplasty (THA) patients aged 30 years or younger and those older than 30 years using a large national database. Methods: The Premier Healthcare Database was utilized to identify primary THA patients from 2015 to 2021 who were aged ≤30 or >30 years. Patient demographics, hospital factors, and primary indications were compared for each cohort. Rates of complications and readmissions were assessed for each cohort by primary indication. Differences were assessed through univariate analysis. Results: Overall, 539,173 primary THA patients were identified (age ≤30: 1849; >30: 537,234). Compared to the >30 cohort, the ≤30 cohort was more likely to be male (56.5% vs 44.9%, P < .001) and non-White (34.0% vs 14.2%, P < .001). The most common indications for THA in the ≤30 cohort were osteonecrosis (49.3%), osteoarthritis (17.8%), and congenital hip deformities (16.0%), and in the >30 cohort, they were osteoarthritis (77.0%), other arthritis (11.3%), and osteonecrosis (5.4%). Patients aged ≤30 years had lower rates of respiratory failure (0.16% vs 0.57%, P < .001), acute renal failure (0.32% vs 1.72%, P < .001), and urinary tract infection (0.38% vs 1.11%, P = .003) than those aged >30 years, but higher rates of wound dehiscence (0.59% vs 0.29%, P = .015) and transfusion (3.68% vs 2.21%, P < .001). There were no differences in 90-day readmission rates (P = .811) or 90-day in-hospital death (P = .173) between cohorts. Conclusions: Younger patients undergoing THA differed significantly in indication, patient characteristics, and hospital factors compared to the older population on univariate analysis. Despite differences in indications, the cohorts did not differ markedly with regard to complication rates in this study.

SAP30 is a core subunit of the transcriptional corepressor SIN3 complex, but little is known about its role in gene regulation and human cancer. Here, we show that SAP30 was a nonmutational oncoprotein upregulated in more than 50% of human breast tumors and correlated with unfavorable outcomes in patients with breast cancer. In various breast cancer mouse models, we found that SAP30 promoted tumor growth and metastasis through its interaction with SIN3A/3B. Surprisingly, the canonical gene silencing role was not essential for SAP30’s tumor-promoting actions. SAP30 enhanced chromatin accessibility and RNA polymerase II occupancy at promoters in breast cancer cells, acting as a coactivator for genes involved in cell motility, angiogenesis, and lymphangiogenesis, thereby driving tumor progression. Notably, SAP30 formed a homodimer with 1 subunit binding to SIN3A and another subunit recruiting MLL1 through specific Phe186/200 residues within its transactivation domain. MLL1 was required for SAP30-mediated transcriptional coactivation and breast tumor progression. Collectively, our findings reveal that SAP30 represents a transcriptional dependency in breast cancer.

The deadliest anaplastic thyroid cancer (ATC) often transforms from indolent differentiated thyroid cancer (DTC); however, the complex intratumor transformation process is poorly understood. We investigated an anaplastic transformation model by dissecting both cell lineage and cell fate transitions using single-cell transcriptomic and genetic alteration data from patients with different subtypes of thyroid cancer. The resulting spectrum of ATC transformation included stress-responsive DTC cells, inflammatory ATC cells (iATCs), and mitotic-defective ATC cells and extended all the way to mesenchymal ATC cells (mATCs). Furthermore, our analysis identified 2 important milestones: (a) a diploid stage, in which iATC cells were diploids with inflammatory phenotypes and (b) an aneuploid stage, in which mATCs gained aneuploid genomes and mesenchymal phenotypes, producing excessive amounts of collagen and collagen-interacting receptors. In parallel, cancer-associated fibroblasts showed strong interactions among mesenchymal cell types, macrophages shifted from M1 to M2 states, and T cells reprogrammed from cytotoxic to exhausted states, highlighting new therapeutic opportunities for the treatment of ATC.

Objectives: T3 disease comprises heterogeneous morphologic characteristics, a variation only further complicated when in the context of N2-confirmed involvement. This study aims to examine whether or not specific features of T3 N2 non–small cell lung cancer are associated with improved 5-year overall survival when using a multimodal therapeutic approach consistent with guideline recommendations compared with definitive surgery alone. Methods: Patients with pathologic T3 N2 non–small cell lung cancer were identified in the National Cancer Database. Therapy modality, as defined by surgery alone versus surgery with adjuvant therapy, and T3 disease descriptors were compared for differences in 5-year overall survival using Kaplan-Meier analysis and log-rank tests. Multivariable Cox regression was used to determine prognostic factors for survival. Results: A total of 1924 patients met the inclusion criteria. Of these, 80.0% (n = 1539) received adjuvant chemotherapy with or without radiation therapy following surgery and 20.0% (n = 385) underwent definitive surgery alone. Patients in the 2 cohorts differed significantly in age, race, insurance status, and Charlson-Deyo score (P

Purpose: The purpose of this study was to train and validate machine learning models for predicting rapid decline of forced expiratory volume in 1 s (FEV1) in individuals with a smoking history at-risk-for chronic obstructive pulmonary disease (COPD), Global Initiative for Chronic Obstructive Lung Disease (GOLD 0), or with mild-to-moderate (GOLD 1–2) COPD. We trained multiple models to predict rapid FEV1 decline using demographic, clinical and radiologic biomarker data. Training and internal validation data were obtained from the COPDGene study and prediction models were validated against the SPIROMICS cohort.Methods: We used GOLD 0–2 participants (n = 3,821) from COPDGene (60.0 ± 8.8 years, 49.9% male) for variable selection and model training. Accelerated lung function decline was defined as a mean drop in FEV1% predicted of > 1.5%/year at 5-year follow-up. We built logistic regression models predicting accelerated decline based on 22 chest CT imaging biomarker, pulmonary function, symptom, and demographic features. Models were validated using n = 885 SPIROMICS subjects (63.6 ± 8.6 years, 47.8% male).Results: The most important variables for predicting FEV1 decline in GOLD 0 participants were bronchodilator responsiveness (BDR), post bronchodilator FEV1% predicted (FEV1.pp.post), and CT-derived expiratory lung volume; among GOLD 1 and 2 subjects, they were BDR, age, and PRMlower lobes fSAD. In the validation cohort, GOLD 0 and GOLD 1–2 full variable models had significant predictive performance with AUCs of 0.620 ± 0.081 (p = 0.041) and 0.640 ± 0.059 (p < 0.001). Subjects with higher model-derived risk scores had significantly greater odds of FEV1 decline than those with lower scores.Conclusion: Predicting FEV1 decline in at-risk patients remains challenging but a combination of clinical, physiologic and imaging variables provided the best performance across two COPD cohorts.

Background: Arthroplasty surgeons use the change in sacral slope (ΔSS) from sitting to standing as a measure of spinal motion. The relationship between ΔSS and the change in lumbar lordosis (ΔLL), an established spinal motion measure, has not been well studied. This study aims to determine the correlation between ΔSS and ΔLL. Methods: Consecutive patients presenting to a spine clinic from 2020 to 2021 at a single institution were retrospectively studied. Standing and sitting lateral radiographs were measured for SS and LL. Patients were divided using ΔSS and ΔLL into stiff (0°-9°), normal (10°-30°), or hypermobile (>30°) category. Patients with a ΔSS-determined normal or hypermobile spine but a ΔLL-determined stiff spine were compared to the rest of the cohort. Results: Overall, 100 patients were included. Of these patients, 47% had the same classification when looking at ΔSS and ΔLL, whereas 53% had conflicting classifications. Twenty percent of patients had a ΔSS-determined normal or hypermobile spine but ΔLL-determined stiff spine. The correlation between ΔSS and ΔLL was 0.510 (P < .001). When isolating patients who underwent lumbar fusion, the correlation between ΔSS and ΔLL was 0.345 (P < .001). Conclusions: ΔSS has a moderate correlation with ΔLL in patients presenting for evaluation of their lumbar spine but low correlation in patients with lumbar fusion. In our cohort, 20% of patients had a ΔSS-determined normal or hypermobile spine but a ΔLL-determined stiff spine, representing a potential high-risk dislocation cohort not captured by ΔSS alone. Arthroplasty surgeons should revisit classifying spinal motion based solely on ΔSS.

Background: This study aims to examine differences in postoperative complications and opioid consumption associated with perioperative peripheral nerve block (PNB) utilization during primary total knee arthroplasty (TKA). Methods: The Premier Healthcare Database was queried for adult patients who underwent primary, elective TKA from 2015 to 2020. Patients who received a femoral or adductor canal PNB were compared to patients who did not. PNB utilization was trended from 2015 to 2020. Univariate and multivariate regression analyses were performed to assess differences in the 90-day risk of postoperative complications between groups. The average inpatient opioid consumption in morphine milligram equivalents was assessed as a function of length of stay. Results: Overall, 609,991 patients were included. PNB utilization increased from 9.29% in 2015 to 30.3% in 2020. After controlling for confounders, the PNB cohort was more likely to have same-day discharge (adjusted odds ratio [aOR] 1.88) and had a decreased risk of periprosthetic joint infection (aOR 0.87), pulmonary embolism (aOR 0.81), and respiratory failure (aOR 0.78). However, there was an increased risk of seroma (aOR 1.75) and hematoma (aOR 1.22) associated with PNB utilization. Lower average overall opioid exposure was seen in the PNB cohort vs no-PNB cohort (82.1 ± 194.7 vs 89.4 ± 214.1 morphine milligram equivalents, P < .001). Conclusions: PNB utilization during primary TKA is associated with a shorter length of stay and decreased risk of multiple postoperative complications, as well as reduced postoperative opioid consumption. These data provide evidence in support of the safety and efficacy of this emerging practice. However, the clinical relevance of an increased risk of seroma and hematoma formation may warrant further investigation.

Background: Duloxetine is a Food and Drug Administration–approved selective norepinephrine reuptake inhibitor for treating depression, anxiety, fibromyalgia, and neuropathic and chronic musculoskeletal pain. This meta-analysis aims to evaluate the efficacy of duloxetine in reducing pain and postoperative opioid use following lower extremity total joint arthroplasty. Methods: A literature search was performed, identifying randomized controlled trials investigating duloxetine for pain management after total hip and total knee arthroplasty. Data from the visual analog scale (VAS) for pain during movement and at rest were extracted for postoperative days (PODs) 1, 3, 7, and 14, as well as postoperative week 6 and postoperative month 3. Opioid use data were obtained at 24, 48 and 72 hours. All data were analyzed using inverse variance with random effects and presented as weighted mean difference. Results: Eight unique studies were identified and included, 7 of which were analyzed quantitatively. Duloxetine decreased postoperative opioid consumption at 48 and 72 hours. For VAS for pain at rest, significantly reduced pain was reported by duloxetine-treated patients at POD 3, POD 7, and postoperative week 6. For VAS for pain at movement, significantly reduced pain was reported by duloxetine-treated patients at POD1, POD 3, POD 7, POD 14, postoperative week 6, and postoperative month 3. Conclusions: Duloxetine appears to decrease postoperative pain and opioid consumption following total joint arthroplasty. However, definitive conclusions are limited by small sample size and study heterogeneity. While there is a need for follow-up studies to determine the optimal dose, duration, and patient population, strong preliminary data provide robust support for future large-scale efficacy studies.

IntroductionO-GlcNAcylation is a type of reversible post-translational modification on Ser/Thr residues of intracellular proteins in eukaryotic cells, which is generated by the sole O-GlcNAc transferase (OGT) and removed by O-GlcNAcase (OGA). Thousands of proteins, that are involved in various physiological and pathological processes, have been found to be O-GlcNAcylated. However, due to the lack of favorable tools, studies of the O-GlcNAcylation and OGT were impeded. Immunoglobulin new antigen receptor (IgNAR) derived from shark is attractive to research tools, diagnosis and therapeutics. The variable domain of IgNARs (VNARs) have several advantages, such as small size, good stability, low-cost manufacture, and peculiar paratope structure.MethodsWe obtained shark single domain antibodies targeting OGT by shark immunization, phage display library construction and panning. ELISA and BIACORE were used to assess the affinity of the antibodies to the antigen and three shark single-domain antibodies with high affinity were successfully screened. The three antibodies were assessed for intracellular function by flow cytometry and immunofluorescence co-localization.ResultsIn this study, three anti-OGT VNARs (2D9, 3F7 and 4G2) were obtained by phage display panning. The affinity values were measured using surface plasmon resonance (SPR) that 2D9, 3F7 and 4G2 bound to OGT with KD values of 35.5 nM, 53.4 nM and 89.7 nM, respectively. Then, the VNARs were biotinylated and used for the detection and localization of OGT by ELISA, flow cytometry and immunofluorescence. 2D9, 3F7 and 4G2 were exhibited the EC50 values of 102.1 nM, 40.75 nM and 120.7 nM respectively. VNAR 3F7 was predicted to bind the amino acid residues of Ser375, Phe377, Cys379 and Tyr 380 on OGT.DiscussionOur results show that shark single-domain antibodies targeting OGT can be used for in vitro detection and intracellular co-localization of OGT, providing a powerful tool for the study of OGT and O-GlcNAcylation.

Photo by Mika Baumeister on Unsplash INTRODUCTION When the COVID-19 pandemic swept the globe, governments and healthcare systems scrambled to control it. While most of the global public health community agreed that actions against the COVID-19 pandemic needed to be prompt and efficient, there were disagreements on what those actions should be. Some governments opted to adopt a containment strategy while others implemented mitigation measures; each had reasons to support their course of action, whether rooted in governmental structures, scientific findings, beliefs, or ethical and moral values. However, the dramatically different response strategies may have led to disparate results. This divide is furthered when ethical and moral values and cultural norms are added to this equation. In this paper, I will examine China and Korea, two countries that implemented a preventative containment strategy, and the United States of America and the United Kingdom, which adopted mitigation strategies. I will examine the differences in their outcomes and whether there is a “correct” response to pandemics like COVID-19. l. Response in China and Korea After its initial discovery in December 2019, COVID-19 rapidly spread beyond China to surrounding countries, including South Korea, Japan, and Singapore. China implemented swift measures drawing on its experience with the SARS outbreak. Measures included lockdowns, contact tracing, testing all individuals exposed to the virus, and consequently enforcing isolation and quarantine provisions.[1] During the early stages, the public health systems and the national government moved to a “health care to all” system to avoid nationwide spread. The government and all sectors of society were mobilized to track, contain, and adapt to the overall state of the epidemic.[2] COVID-19 continued and spread in China during Lunar New Year celebrations when population movement within the country was at its peak. Thus, Wuhan entered lockdown to control the number of infected people leaving the city to contain the virus;[3] even in areas where there were few to no cases, the general population of China voluntarily abided by measures like those implemented in Wuhan. The measures included wearing masks, social distancing, and following stay-at-home orders. Furthermore, healthcare workers from all over the country volunteered to travel to Hubei, where Wuhan is, and assembled several Fangcang shelter hospitals.[4] Fangcang hospitals were designed based on emergency medical care cabins that were used after two devastating earthquakes in China and served as temporary quarantine housing and hospital facilities.[5] They are mobile, have fast deployment, and can adapt quickly to different environments. At the start of the pandemic, Wuhan converted gymnasiums, convention centers, sports arenas and training centers, factories, and other venues into Fangcang hospitals. Although temporary, these quarantine hospital facilities were equipped with full medical equipment and personnel, allowing for complete medical functions for “treatment, disease monitoring, diagnosis and other clinical tasks.”[6] Teams of psychologists were also assigned to each hospital to provide counseling for patients.[7] Beyond separating those who were infected from the rest of the population and thus having more control over the community spread of the virus, Fangcang hospitals played a vital role in reducing patient density in traditional hospitals and medical centers by expanding treatment capacities.[8] South Korea reported its first COVID-19 case in January 2020, and, within days, the government activated the Central Disaster and Safety Countermeasures Headquarters.[9] Similar to China, South Korea used existing epidemic protocols and implemented the 3Ts strategy, prioritizing testing, tracing, and treatment.[10] High-capacity screening facilities and working with the private sector to ensure an adequate supply of tests made South Korea’s efforts successful.[11] The South Korean government strictly regulated self-isolation and quarantine. Contact tracing efforts used various data sources, “including credit card transactions and closed-circuit television footage.”[12] The government also placed stringent restrictions on travel, beginning with designated entry lines and questionnaires, but expanding to include temperature checks, testing for all travelers at the border, and a mandatory fourteen-day monitored quarantine for anyone entering the country.[13] The majority of the population responded immediately with compliance, with national weekly movement decreasing by 38 percent between February 24, 2020, and March 1, 2020, compared to the corresponding week the previous month. Schools swiftly closed across the nation, and the entire country transitioned to remote learning until the gradual reopening in May and June 2020.[14] There was some discontentment within the population, especially with the South Korean government’s practice of publicly announcing the names of individuals who tested positive.[15] Critics of this practice say it is an infringement of patient privacy and can even be viewed as an invitation to public bullying.[16] However, even with some dissatisfaction with government regulations, a survey of 1,200 South Koreans in September 2020 asking people to agree if they were satisfied with the government’s response showed that the overwhelming majority either agreed or strongly agreed (44.08 percent and 19.75 percent, respectively), and less than 20 percent of the respondents either disagreed or strongly disagreed (11.50 percent and 5.08 percent, respectively).[17] Regulations surrounding isolation and quarantine were strict and applied to those with confirmed cases of COVID-19, anyone who traveled internationally, or individuals suspected to be infected. Individuals were required to use the Self-Quarantine Safety Protection app that tracked location for fourteen days to ensure that quarantine protocols were followed.[18] Case officers monitored the app, and violators not only faced a substantial fine but were also required to wear electronic wristbands that would alert the officers if the individual left the location of their mobile device.[19] ll. The Western Response: The UK and US COVID-19 was reported in many Western nations around January 2020. However, unlike South Korea, many countries did not immediately respond to the outbreak with surveillance and containment strategies but had a wait-and-see approach. As the pandemic worsened, they gradually adopted mitigation strategies to combat the disease as it progressed. While the US adopted a combination of containment and mitigation strategies, a concrete response from state and federal governments did not occur until March 2020.[20] Even then, many states did little to address the pandemic. Although equipped with a robust healthcare system, a shortage of ventilators and hospital beds became evident in some localities early on. The US healthcare system failed to acknowledge the pandemic and prepare a coordinated response in time to stop the momentum of the disease.[21] The goal became “flattening the curve” (keeping the number of cases that needed hospital care low enough to avoid overwhelming the hospital system) as it was clear containment would be impossible. Once tests were developed, poor coordination of testing efforts and insufficient resources to test at the necessary scale to provide comprehensive national surveillance of the disease further hindered efforts to contain infected individuals and decelerate its spread.[22] Eventually, regulations and mitigation measures were implemented, including mask mandates, school closures, caps or bans on in-person gatherings, and the closure of non-essential businesses.[23] However, enforcement of these measures proved difficult, and people instigated protests against many of the recommended policies and requirements. The UK and the US both encountered a shortage of personal protective equipment for healthcare workers.[24] However, a more prominent problem arose from the UK’s initial response to the pandemic. The UK first said COVID-19 was like influenza and therefore did not call for emergency measures to deter its spread.[25] Furthermore, in the first few weeks of the pandemic, the UK government believed herd immunity was the best course of action, stating that most people would have mild symptoms,[26] and the population would become mostly immune to the virus once enough people were infected.[27] In theory, herd immunity was a potentially effective strategy. The public health authorities thought that if the threshold for herd immunity was reached, enough people would have developed protective antibodies against any future infection.[28] However, the risks of COVID-19 were high and the cases “would lead to high rates of hospitalization and need for critical care, straining health service capacity past the breaking point.”[29] Furthermore, while getting COVID-19 would offer some natural immunity against reinfection, reinfection remained a possibility, especially during the early stages of the pandemic when vaccines were unavailable.[30] Later, when vaccines were available, a study showed that an unvaccinated person who contracted the virus was more than twice as likely to become reinfected than a fully vaccinated person.[31] The UK government also expressed concern for “behavioral fatigue.”[32] It claimed that if restrictions were enforced pre-emptively and prematurely, people might become progressively “uncooperative and less vigilant.”[33] Regarding the concern for “behavioral fatigue,” numerous behavioral scientists stated that they were unconvinced that this reason was enough to hold off implementing restrictions. There was a lack of evidence of this phenomenon, and a group of 681 UK behavioral scientists said in an open letter that “[s]uch evidence is necessary if we are to base a high-risk public health strategy on it.”[34] Fortunately, this strategy only remained under consideration for a short period. After rapid increases in confirmed cases and deaths due to COVID-19, the UK government implemented more strict measures, like city lockdown, school closures, and the closure of non-essential businesses.[35] These restrictions took legal effect on March 26th, 2020 – around two weeks after the first proposal of the “herd immunity” strategy.[36] lll. Comparing the Two Approaches The Eastern and Western countries experienced significant outbreaks of COVID-19. However, looking at the mortality rate and new confirmed cases, the differences between the two categories of response to COVID-19 are significant. As of December 31, 2020, the mortality rate per 100,000 population for China and South Korea were 0.3 and 1.8, respectively, and new confirmed cases per day per 100,000 population were 87 and 1,029, respectively. However, the mortality rates per 100,000 in the US and the UK were 107 and 108, respectively, and they had up to 234,133 and 56,029 new confirmed cases every day, respectively.[37] As of July 2022, total deaths in China were 22, 994[38] (population 1.45 billion)[39] and in South Korea 24,794[40] (population 51.36 million)[41] compared to 1,015,093[42] in the US (population 335.03 million)[43] and 182,727[44] in the UK (population 68.62 million).[45] Further differences can be seen in the varying sectors of society, such as healthcare systems and authority models, political structures, and cultural customs among these countries, which in turn affect the response and control strategies.[46] In the US and the UK, rights-based political structures affected the response, making tracking and surveillance more problematic early on. But Western countries did have strict lockdowns and quarantines. China and South Korea maintained a proactive approach by “identifying and managing cases, tracking and isolating close contacts, and strictly restricting or controlling population movement when feasible and appropriate.”[47] In contrast, the UK implemented nationwide lockdowns early on, and the US restrictions varied among states. Both the UK and the US focused on treating the severe cases and those with underlying conditions rather than proactively preventing new cases from developing in the early pandemic.[48] They did shift gears to mass testing schemes and attempts to slow transmission. By the time they implemented cohesive strategies, COVID-19 was widespread. Due to their slow initial responses, they needed to manage an onslaught of cases while trying to prevent transmission. lV. Ethical Implications The “West vs. Rest” culture divide emerges when comparing the COVID-19 response strategies of East Asian countries to those of Western countries. The differences in their strategies further highlight the differences in the prevailing moral values influencing public policy. The preventative stance adopted by many East Asian countries shows a stronger collective identity among citizens. But it also may show more substantial governmental power and less appetite for protest. In contrast, the mostly non-interfering nature of Western governments’ actions shows a reliance on the “autonomous and unanimous responsibility of individuals.”[49] The moral values in the US also may reflect the prioritized position of personal rights and the suspicion of intrusive government policies. Culturally, the populations of South Korea and China are generally more tolerant of personal data-sharing and monitoring, suggesting there is less concern for autonomy or privacy. However, many people in the US and UK would consider the use of location tracking apps and electronic bracelets to be violations of individual autonomy and privacy.[50] Sectors of the Western world also argue that mandating masking or social distancing imposes on individual autonomy and free will. Mask-wearing was an existing practice in East Asian countries, even without mandates or pandemics. Individuals wear masks for common colds and influenza and do not consider a mask requirement an infringement of their autonomy. Furthermore, whether it is due to the authoritarian nature of the government or not, there is a general tendency toward public compliance and accepting government policies in many East Asian countries,[51] and the lack of public dissent played an important part in making combating COVID-19 easier for countries like China and South Korea. The lack of initiative from Western nations arguably violates the bioethical principles of beneficence and nonmaleficence.[52] For example, the promotion of the “herd immunity” strategy from the UK government and consequently the government’s inaction, risked the well-being of its citizens. The government failed to avoid the harm that COVID-19 brought. Similarly, by delaying its response until nearly two months after the initial case was reported, the US also violated the principle of non-maleficence. The success seen in South Korea and China during the early pandemic better exemplifies beneficence and nonmaleficence. The strategy of contact tracing and strict containment saved lives. The consequences of the restrictions varied across the countries as well. Not everyone can afford to self-isolate or quarantine and being required to do so can significantly impact many individuals’ well-being. Furthermore, not everyone’s occupation allows them to work from home and business closures disadvantaged portions of the population disparately. For those who are essential workers, school closures may also burden parents who do not have access to affordable childcare. The stringent restrictions regarding quarantine and self-isolation in East Asian countries also harmed people disparately, raising problems surrounding the principle of justice. However, the speed at which China had COVID-19 contained allowed people there to return to their normal lives quickly. Compared to some Western countries’ waves of lockdown and reinforcement of restrictions, the “zero-COVID” strategy in countries like China showed success, at least during the early stages of the pandemic. The contact tracing and containment was likely financially beneficial. While the pandemic resulted in substantial economic growth downgrades and global recessions, regions like East Asia were estimated to grow by around 0.5 percent. In comparison, the economy in regions like Europe contracted by around 4.7 percent.[53] CONCLUSION China arguably had an advantage in combating COVID-19 since the outbreak was relatively concentrated in one region. This allowed early detection of symptoms and quick containment of the virus. Other countries, like the US, had new cases on both coasts early in the pandemic; thus, containment was more challenging than it was in China. However, the delayed and reluctant response from countries like the US and the UK did not benefit the well-being of their populations and proved to put more stress on their healthcare systems. While mass tracking of people is politically contentious, the promptness of actions many East Asian countries employed at the beginning of COVID-19 seemed to be the more effective course of action that best protected the well-being of their citizens. - [1] Chen, Haiqian, et al. “Response to the COVID-19 Pandemic: Comparison of Strategies in Six Countries.” Frontiers in Public Health, vol. 9, September 30, 2021, pp. 1-11. doi: 10.3389/fpubh.2021.708496. [2] Chen, et al. [3] Chen, et al. [4] Chen, et al. [5] Wang, Ke-Wei, et al. “Fangcang shelter hospitals are a One Health approach for responding to the COVID-19 outbreak in Wuhan, China.” One Health, vol. 10, August 29th, 2020, pp. 1-6. doi: 10.1016/j.onehlt.2020.100167. https://www.sciencedirect.com/science/article/pii/S2352771420302688. [6] Wang. [7] Wang. [8] Wang. [9] Kim, June-Ho, et al. “Emerging COVID-19 Success Story: South Korea Learned the Lesson of MERS.” Our World Data, University of Oxford, March 5, 2021. https://ourworldindata.org/covid-exemplar-south-korea. [10] Chen, Haiqian, et al. [11] Kim, et al. [12] Kim. [13] Kim. [14] Scott, Dylan and Jun Michael Park. “South Korea’s Covid-19 success story started with failure.” Vox, April 19, 2021. https://www.vox.com/22380161/south-korea-covid-19-coronavirus-pandemic-contact-tracing-testing.. [15] Scott and Park. [16] Rich, Timothy S., et al. “What Do South Koreans Think of Their Government’s COVID-19 Response?” The Diplomat, October 7, 2020. https://thediplomat.com/2020/10/what-do-south-koreans-think-of-their-governments-covid-19-response/. [17] Rich, et al. [18] Kim, et al. [19] Kim, et al. [20] Chen, et al. [21] Chen, et al. [22] Chen, et al. [23] Chen, et al. [24] Chen, et al. [25]Chen, et al. [26] Chen, et al. [27] O’Grady, Cathleen. “The U.K. backed off on herd immunity. To beat COVID-19, we’ll ultimately need it.” National Geographics, March 20, 2020. https://www.nationalgeographic.com/science/article/uk-backed-off-on-herd-immunity-to-beat-coronavirus-we-need-it. [28] “Herd immunity and COVID-19: What you need to know.” Mayo Clinic, April 20, 2022. https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/herd-immunity-and-coronavirus/art-20486808?p=1. [29] O’Grady. [30] O’Grady. [31] Mayo Clinic, April 20, 2022. [32] Yong, Ed. “The UK’s Coronavirus ‘Herd Immunity’ Debacle.” The Atlantic, March 16, 2020. https://www.theatlantic.com/health/archive/2020/03/coronavirus-pandemic-herd-immunity-uk-boris-johnson/608065/. [33] Yong. [34] Harvey, Nigel. “Behavioral Fatigue: Real Phenomenon, Naïve Construct or Policy Contrivance?” Frontiers in Psychology, vol. 11, November 6, 2020. doi: 10.3389/fpsyg.2020.589892, quoting a March 16, 2020 open letter to the UK government. [35] Chen, et al. [36]“Timeline of UK coronavirus lockdowns, March 2020 to March 2021.” Institute for Government Analysis. https://www.instituteforgovernment.org.uk/sites/default/files/timeline-lockdown-web.pdf. [37] Chen, et al. [38] “China: WHO Coronavirus Disease (COVID-19) Dashboard.” World Health Organization, 2022, https://covid19.who.int/region/wpro/country/cn. [39] “China Population.” Worldometer, 2022, https://www.worldometers.info/world-population/china-population/. [40] “The Republic of South Korea: WHO Coronavirus Disease (COVID-19) Dashboard.” World Health Organization, 2022, https://covid19.who.int/region/wpro/country/kr. [41] “South Korea Population,” Worldometer, 2022, https://www.worldometers.info/world-population/south-korea-population/. [42] “The United States of America: WHO Coronavirus Disease (COVID-19) Dashboard.” World Health Organization, 2022, https://covid19.who.int/region/amro/country/us. [43] “United States Population,” Worldometer, 2022, https://www.worldometers.info/world-population/us-population/. [44] “The United Kingdom: WHO Coronavirus Disease (COVID-19) Dashboard.” World Health Organization, 2022, https://covid19.who.int/region/euro/country/gb. [45] “U.K. Population,” Worldometer, 2022, https://www.worldometers.info/world-population/uk-population/. [46] Chen, et al. [47] Chen, et al., p 6. [48] Chen, et al. [49] Festing, Marion, Tobias Schumacher and Yong-Yueh Lee. “How Cultural Norms and Values Shape National Responses to the COVID-19 Pandemic.” The London School of Economics and Political Science, April 15, 2021. https://blogs.lse.ac.uk/businessreview/2021/04/15/how-cultural-norms-and-values-shaped-national-responses-to-the-covid-19-pandemic/. [50] Festing, et al. [51] Festing, et al. [52] Beauchamp, Tom L. and James F. Childress. Principles of Biomedical Ethics. (New York: Oxford University Press, 2009). [53] “The Global Economic Outlook During the COVID-19 Pandemic: A Changed World.” The World Bank, June 8, 2020. https://www.worldbank.org/en/news/feature/2020/06/08/the-global-economic-outlook-during-the-covid-19-pandemic-a-changed-world.

In addition to scavenging exogenous cholesterol, the parasitic kinetoplastid Trypanosoma cruzi can endogenously synthesize sterols. Similar to fungal species, T. cruzi synthesizes ergostane type sterols and is sensitive to a class of azole inhibitors of ergosterol biosynthesis that target the enzyme lanosterol 14α-demethylase (CYP51). In the related kinetoplastid parasite Leishmania donovani, CYP51 is essential, yet in Leishmania major, the cognate enzyme is dispensable for growth; but not heat resistance. The essentiality of CYP51 and the specific role of ergostane-type sterol products in T. cruzi has not been established. To better understand the importance of this pathway, we have disrupted the CYP51 gene in T. cruzi epimastigotes (ΔCYP51). Disruption of CYP51 leads to accumulation of 14-methylated sterols and a concurrent absence of the final sterol product ergosterol. While ΔCYP51 epimastigotes have slowed proliferation compared to wild type parasites, the enzyme is not required for growth; however, ΔCYP51 epimastigotes exhibit sensitivity to elevated temperature, an elevated mitochondrial membrane potential and fail to establish growth as intracellular amastigotes in vitro. Further genetic disruption of squalene epoxidase (ΔSQLE) results in the absence of all endogenous sterols and sterol auxotrophy, yet failed to rescue tolerance to stress in ΔCYP51 parasites, suggesting the loss of ergosterol and not accumulation of 14-methylated sterols modulates stress tolerance.

BackgroundTotal annual cancer rates have decreased due to improved treatment and prevention. However, the incidence of melanoma is rising, and not all patients respond to immune and targeted approaches. Therefore, we sought to determine the efficacy of red light (RL) phototherapy in preclinical models of melanoma.MethodsMelanoma cells (A375, B16F10, MNT-1) were irradiated with RL. Melanoma proliferation, apoptosis, oxidative stress, and p53 phosphorylation were measured in vitro. In C57BL/6 mice, phototherapy safety, B16F10 tumor growth, and immunocyte infiltration were assessed following RL.ResultsIn vitro, 640 J/cm2 RL decreased cellular proliferation without increasing apoptosis, while 1280 J/cm2 increased apoptosis. RL increased intracellular reactive oxygen species generation and p53 phosphorylation. In animal models, 2560 J/cm2 RL significantly prevented melanoma growth and increased the expression of CD103+ dendritic cells. 1280 and 1920 J/cm2 RL decreased tumor volume, but not significantly. RL did not cause skin inflammation or erythema in normal skin.ConclusionRL represents a potentially safe and effective melanoma therapeutic. RL prevented tumor growth and increased the expression of immune markers, such as CD103, that are associated with favorable melanoma outcomes. Further research is needed to determine the optimal clinical treatment regimen for melanoma using RL.