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1.
Clin Infect Dis ; 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38922669

ABSTRACT

INTRODUCTION: Data on protection afforded by updated COVID-19 vaccines (bivalent/XBB 1.5 monovalent) against the emergent JN.1 variant remains limited. METHODS: We conducted a retrospective population-based cohort study amongst all boosted Singaporeans aged ≥18 years during a COVID-19 wave predominantly driven by JN.1, from 26th November 2023 to 13th January 2024. Multivariable Cox regression was utilised to assess risk of SARS-CoV-2 infection and COVID-19 associated emergency-department (ED) visits/hospitalizations, stratified by vaccination status/prior infection; with individuals last boosted ≥1 year utilized as the reference category. Vaccination and infection status were classified using national registries. RESULTS: 3,086,562 boosted adult Singaporeans were included in the study population, accounting for 146,863,476 person-days of observation. During the JN.1 outbreak, 28,160 SARS-CoV-2 infections were recorded, with 2,926 hospitalizations and 3,747 ED-visits. Compared with individuals last boosted ≥1 year prior with ancestral monovalent vaccines, receipt of an updated XBB.1.5 booster 8-120 days prior was associated with lower risk of JN.1 infection (adjusted-hazard-ratio, aHR = 0.59[0.52-0.66]), COVID-19 associated ED-visits (aHR = 0.50[0.34-0.73]) and hospitalizations(aHR = 0.58[0.37-0.91]), while receipt of a bivalent booster 121-365 days prior was associated with lower risk of JN.1 infection (aHR = 0.92[0.88-0.95]) and ED-visits (aHR = 0.80[0.70-0.90]). Lower risk of COVID-19 hospitalization during the JN.1 outbreak (aHR = 0.57[0.33-0.97]) was still observed following receipt of an updated XBB.1.5 booster 8-120 days prior, even when analysis was restricted to previously infected individuals. CONCLUSION: Recent receipt of updated boosters conferred protection against SARS-CoV-2 infection and ED-visits/hospitalization during a JN.1 variant wave, in both previously infected and uninfected individuals. Annual booster doses confer protection during COVID-19 endemicity.

2.
Article in English | MEDLINE | ID: mdl-38908748

ABSTRACT

OBJECTIVES: Evidence suggests that some COVID-19 survivors experience a wide range of post-COVID-19 sequelae; however, the majority of studies were conducted prior to emergence of the milder Omicron variant. We examined the post-acute risk of new incident cardiovascular complications after SARS-CoV-2 infection in a multi-ethnic Asian population, during Omicron predominance. METHODS: This cohort study used national testing and healthcare claims databases in Singapore to build a cohort of individuals with confirmed SARS-CoV-2 infection during Omicron BA.1/2 transmission, and a contemporaneous test-negative group. Participants in both groups were followed up for a median of 300 days. We estimated risks of new-incident cardiovascular complications using doubly robust competing-risks survival analysis. Risks were reported using two measures: hazard ratio (HR) and excess burden (EB). RESULTS: We included 375,903 test-positive, infected individuals (mean age 48 years) and 619,379 test-negative controls (mean age 47 years). The majority (97.5%, 366,593/375,903) of infected individuals had mild infection not requiring hospitalisation. There was no overall increased risk of new-incident cardiovascular complications, (adjusted-hazards-ratio, aHR = 1.01 [0.97-1.07]) amongst COVID-19 survivors when compared against test-negatives. A modestly increased risk and excess burden of dysrhythmias amongst COVID-19 survivors (aHR=1.09 [1.01- 1.19]) was observed. Risk and burdens of new-incident cardiovascular complications predominantly accrued in hospitalised (aHR=5.52 [3.76-8.10]) and severe (aHR=5.52 [3.76-8.10]) COVID-19 cases. CONCLUSIONS: No significantly increased overall risk of any cardiovascular complication was observed in the 300 days following COVID-19 infection during the Omicron-dominant period when compared against test-negatives, with the exception of a small increased occurrence of dysrhythmias.

3.
Article in English | MEDLINE | ID: mdl-38918090

ABSTRACT

OBJECTIVES: Hypertrophic obstructive cardiomyopathy (HOCM) may be treated by septal myectomy. Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication, but little is known about its incidence after septal myectomy. The objectives of this work were to evaluate the prevalence of CSA-AKI after septal myectomy and identify potential perioperative and phenotype-related factors contributing to CSA-AKI. DESIGN: This was a retrospective database analysis with new data analysis. SETTING: The study occurred in a single university academic expertise center for septal myectomy HOCM patients. PARTICIPANTS: Data from 238 HOCM patients with septal myectomy operated on between 2005 and 2022 were collected. INTERVENTIONS: CSA-AKI was stratified according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines using measurement of creatinine and urine production. Important HOCM phenotype-related and perioperative factors were analyzed for their possible associations with CSA-AKI. MEASUREMENTS AND MAIN RESULTS: CSA-AKI occurred in 45% of patients; of these, 55% were classified as KDIGO stage I and the remaining 45% as stage II, with no chronic kidney damage observed. Moreover, there were no phenotypical or perioperative characteristics that were more prevalent in the CSA-AKI cohort. However, the use of beta-blockers and coronary artery disease were more prevalent in the CSA-AKI cohort. CONCLUSIONS: CSA-AKI is a common complication after septal myectomy but was transient, and kidney function recovered in all patients.

4.
J Foot Ankle Surg ; 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38825307

ABSTRACT

Ankle fracture fixation using intramedullary fibular (IMF) nails has been shown to allow for earlier weightbearing, reduced wound complications, better union rates, and the absence of prominent hardware, compared to plates/screw (PS) constructs. The purpose of present retrospective cohort study was to compare outcomes of patients who underwent ankle fracture fixation using an IMF nail versus PS. Demographic, clinical, and radiographic data were recorded for patients who underwent ankle fracture fixation between May 2020 and May 2022, and who were at least 1 year postoperative. Toe-touch weightbearing was permitted immediately after surgery, protected weightbearing (PWB) at postoperative week 2, and weightbearing as tolerated in a brace at week 6. Radiographs were assessed preoperatively, and at 2, 6, 12, 24, and 48 weeks postoperative. Sixty-one ankle fractures (30 IMF, 31 PS) with a mean follow up of 14.7 and 18 (range, 12 to 23) months were included. Overall, the IMF nail cohort had less pain, faster time to union (11.4 vs 13.2 weeks), and less complications (23% vs 45%), reoperations (10% vs 16%), and surgical failures (9% vs 9.7%), compared to the PS cohort. The differences were not statistically significant. The PS cohort had a higher rate of symptomatic hardware irritation (p =< .001). Tobacco use adversely effected direct osseous healing (p < .001) and increased postoperative complications (p = .050). The present study lends credence to the previously reported advantages of IMF nailing over PS fixation for ankle fractures. Ankle fracture fixation using a fourth generation, IMF nail is a viable alternative to traditional PS fixation.

5.
Chest ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38871281

ABSTRACT

BACKGROUND: Individuals with chronic-lung-disease (CLD) are more susceptible to respiratory viral infections; however, there is significant heterogeneity in the literature on CLD and COVID-19 outcomes. Data is lacking on outcomes with newer variants (eg. Omicron) and in vaccinated/boosted populations. RESEARCH QUESTION: What are the outcomes of SARS-CoV-2 infection in individuals with CLD during Delta and Omicron transmission, in a highly vaccinated/boosted population-based cohort? STUDY DESIGN AND METHODS: Outcomes of Delta/Omicron SARS-CoV-2 infection in a highly vaccinated/boosted cohort of adult Singaporeans with CLD (including asthma, chronic-obstructive-pulmonary-disease [COPD], bronchiectasis and pulmonary fibrosis) were contrasted against matched population controls. Calendar time-scale Cox regressions were used to compare risk of infection, COVID-19-related hospitalizations and severe COVID-19 disease, adjusting for sociodemographic factors/comorbidities. RESULTS: Overall, 68,782 individual patients with CLD and 534,364 matched population controls were included. 92.7% of CLD patients were boosted by the end of the Omicron wave. Compared with controls, higher risk of SARS-CoV-2 infection, COVID-19-related hospitalization and severe COVID-19 was observed amongst patients with CLD during both Delta (infection: adjusted-hazards-ratio, aHR=1.22[1.17-1.28]; hospitalization: aHR=1.76[1.61-1.92]; severe-COVID-19: aHR=1.75[1.50-2.05]) and Omicron waves (infection: aHR=1.15[1.14-1.17]; hospitalization: aHR=1.82[1.74-1.91]; severe-COVID-19: aHR=2.39[2.18-2.63]). During Omicron, significantly higher risk of infection, hospitalization and severe-COVID-19 was observed amongst patients with asthma (severe-COVID-19: aHR=1.31[1.10-1.55]) and COPD (severe-COVID-19: aHR=1.36[1.12-1.66]) compared with controls. Severe exacerbation (requiring hospitalization) in the preceding year was associated with higher risk of poorer outcomes (Delta-severe-COVID-19: aHR=9.84[6.33-15.28]; Omicron-severe-COVID-19: aHR=19.22[15.35-24.06]). Risk was attenuated in the boosted group, with numerically lower HRs against hospitalization/severe-COVID-19 in the 4-dose group compared with the 3-dose group. INTERPRETATION: Increased risk of COVID-19-related hospitalization and severe-COVID-19 was observed amongst patients with CLD compared with matched population controls, during Delta/Omicron predominance. Boosting attenuated serious COVID-19 outcomes.

6.
JCI Insight ; 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38869953

ABSTRACT

Duodenal bicarbonate secretion is critical to epithelial protection, nutrient digestion/absorption and is impaired in cystic fibrosis (CF). We examined if linaclotide, typically used to treat constipation, may also stimulate duodenal bicarbonate secretion. Bicarbonate secretion was measured in vivo and in vitro using mouse and human duodenum (biopsies and enteroids). Ion transporter localization was identified with confocal microscopy and de novo analysis of human duodenal single cell RNA sequencing (sc-RNAseq) datasets was performed. Linaclotide increased bicarbonate secretion in mouse and human duodenum in the absence of CFTR expression (Cftr knockout mice) or function (CFTRinh-172). NHE3 inhibition contributed to a portion of this response. Linaclotide-stimulated bicarbonate secretion was eliminated by down-regulated in adenoma (DRA, SLC26A3) inhibition during loss of CFTR activity. Sc-RNAseq identified that 70% of villus cells expressed SLC26A3, but not CFTR, mRNA. Loss of CFTR activity and linaclotide increased apical brush border expression of DRA in non-CF and CF differentiated enteroids. These data provide further insights into the action of linaclotide and how DRA may compensate for loss of CFTR in regulating luminal pH. Linaclotide may be a useful therapy for CF individuals with impaired bicarbonate secretion.

7.
Nature ; 630(8016): 457-465, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38750365

ABSTRACT

Adoptively transferred T cells and agents designed to block the CD47-SIRPα axis are promising cancer therapeutics that activate distinct arms of the immune system1,2. Here we administered anti-CD47 antibodies in combination with adoptively transferred T cells with the goal of enhancing antitumour efficacy but observed abrogated therapeutic benefit due to rapid macrophage-mediated clearance of T cells expressing chimeric antigen receptors (CARs) or engineered T cell receptors. Anti-CD47-antibody-mediated CAR T cell clearance was potent and rapid enough to serve as an effective safety switch. To overcome this challenge, we engineered the CD47 variant CD47(Q31P) (47E), which engages SIRPα and provides a 'don't eat me' signal that is not blocked by anti-CD47 antibodies. TCR or CAR T cells expressing 47E are resistant to clearance by macrophages after treatment with anti-CD47 antibodies, and mediate substantial, sustained macrophage recruitment to the tumour microenvironment. Although many of the recruited macrophages manifested an M2-like profile3, the combined therapy synergistically enhanced antitumour efficacy. Our study identifies macrophages as major regulators of T cell persistence and illustrates the fundamental challenge of combining T-cell-directed therapeutics with those designed to activate macrophages. It delivers a therapeutic approach that is capable of simultaneously harnessing the antitumour effects of T cells and macrophages, offering enhanced potency against solid tumours.


Subject(s)
CD47 Antigen , Immunotherapy, Adoptive , Neoplasms , T-Lymphocytes , Animals , Female , Humans , Male , Mice , Antigens, Differentiation/immunology , Antigens, Differentiation/metabolism , CD47 Antigen/genetics , CD47 Antigen/immunology , CD47 Antigen/metabolism , Cell Line, Tumor , Immunotherapy, Adoptive/methods , Macrophages/cytology , Macrophages/immunology , Neoplasms/immunology , Neoplasms/metabolism , Neoplasms/therapy , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/metabolism , Receptors, Chimeric Antigen/genetics , Receptors, Chimeric Antigen/immunology , Receptors, Chimeric Antigen/metabolism , Receptors, Immunologic/immunology , Receptors, Immunologic/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , T-Lymphocytes/transplantation , Tumor Microenvironment/immunology , Antibodies/immunology , Antibodies/therapeutic use , Macrophage Activation
8.
J R Stat Soc Ser C Appl Stat ; 73(2): 522-539, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38746649

ABSTRACT

In precision medicine, there is much interest in estimating the expected-to-benefit (EB) subset, i.e. the subset of patients who are expected to benefit from a new treatment based on a collection of baseline characteristics. There are many statistical methods for estimating the EB subset, most of which produce a 'point estimate' without a confidence statement to address uncertainty. Confidence intervals for the EB subset have been defined only recently, and their construction is a new area for methodological research. This article proposes a pseudo-response approach to EB subset estimation and confidence interval construction. Compared to existing methods, the pseudo-response approach allows us to focus on modelling a conditional treatment effect function (as opposed to the conditional mean outcome given treatment and baseline covariates) and is able to incorporate information from baseline covariates that are not involved in defining the EB subset. Simulation results show that incorporating such covariates can improve estimation efficiency and reduce the size of the confidence interval for the EB subset. The methodology is applied to a randomized clinical trial comparing two drugs for treating HIV infection.

9.
Nat Commun ; 15(1): 3741, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38702301

ABSTRACT

Targeted therapy is effective in many tumor types including lung cancer, the leading cause of cancer mortality. Paradigm defining examples are targeted therapies directed against non-small cell lung cancer (NSCLC) subtypes with oncogenic alterations in EGFR, ALK and KRAS. The success of targeted therapy is limited by drug-tolerant persister cells (DTPs) which withstand and adapt to treatment and comprise the residual disease state that is typical during treatment with clinical targeted therapies. Here, we integrate studies in patient-derived and immunocompetent lung cancer models and clinical specimens obtained from patients on targeted therapy to uncover a focal adhesion kinase (FAK)-YAP signaling axis that promotes residual disease during oncogenic EGFR-, ALK-, and KRAS-targeted therapies. FAK-YAP signaling inhibition combined with the primary targeted therapy suppressed residual drug-tolerant cells and enhanced tumor responses. This study unveils a FAK-YAP signaling module that promotes residual disease in lung cancer and mechanism-based therapeutic strategies to improve tumor response.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Drug Resistance, Neoplasm , Lung Neoplasms , Signal Transduction , Transcription Factors , YAP-Signaling Proteins , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Signal Transduction/drug effects , Transcription Factors/metabolism , Transcription Factors/genetics , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , YAP-Signaling Proteins/metabolism , Cell Line, Tumor , Animals , Drug Resistance, Neoplasm/genetics , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/genetics , Neoplasm, Residual , Mice , Focal Adhesion Kinase 1/metabolism , Focal Adhesion Kinase 1/genetics , ErbB Receptors/metabolism , ErbB Receptors/genetics , Anaplastic Lymphoma Kinase/metabolism , Anaplastic Lymphoma Kinase/genetics , Anaplastic Lymphoma Kinase/antagonists & inhibitors , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Antineoplastic Agents/therapeutic use , Antineoplastic Agents/pharmacology , Xenograft Model Antitumor Assays
10.
SAGE Open Med Case Rep ; 12: 2050313X241252344, 2024.
Article in English | MEDLINE | ID: mdl-38784245

ABSTRACT

Verrucous carcinoma is a well-recognized low-grade variant of squamous cell carcinoma. Cutaneous, oral, and anogenital forms exist. Exposure to persistent chronic irritation, inflammation, and repeated injury, as well as carcinogenic agents such as human papillomavirus infection, smoking, and alcohol use, are established risk factors. These neoplasms occur mostly in the oral cavity. The usual extraoral sites include the larynx, esophagus, genitals, and perineum. It is an extremely uncommon site of occurrence for the extraoral chin region. This unusual location makes the index case unique. Other uncommon sites reported include finger and foot. Case studies of verrucous carcinoma with huge tumor sizes are rare. Although it can be destructive locally, verrucous carcinoma typically does not spread to distant sites. Wide surgical excision with free margins is the most common treatment approach with a favorable prognosis. These tumors are likely to recur if they are incompletely excised, and recurred lesions tend to be more aggressive clinically as compared to their original counterparts. Herein, the authors describe a case of a huge oral verrucous carcinoma localized on the chin of a 43-year-old female patient. The clinical course, diagnostics, and proposed treatment have been discussed with the existing available literature.

11.
Trends Neurosci ; 2024 May 22.
Article in English | MEDLINE | ID: mdl-38782701

ABSTRACT

Sensory systems experience a period of intrinsically generated neural activity before maturation is complete and sensory transduction occurs. Here we review evidence describing the mechanisms and functions of this 'spontaneous' activity in the auditory system. Both ex vivo and in vivo studies indicate that this correlated activity is initiated by non-sensory supporting cells within the developing cochlea, which induce depolarization and burst firing of groups of nearby hair cells in the sensory epithelium, activity that is conveyed to auditory neurons that will later process similar sound features. This stereotyped neural burst firing promotes cellular maturation, synaptic refinement, acoustic sensitivity, and establishment of sound-responsive domains in the brain. While sensitive to perturbation, the developing auditory system exhibits remarkable homeostatic mechanisms to preserve periodic burst firing in deaf mice. Preservation of this early spontaneous activity in the context of deafness may enhance the efficacy of later interventions to restore hearing.

12.
Mol Ther ; 2024 May 07.
Article in English | MEDLINE | ID: mdl-38715361

ABSTRACT

We investigated long-term human coagulation factor IX (huFIX) expression of a novel variant when delivered into mice and rhesus macaques and compared transduction efficiencies using two different adeno-associated virus (AAV) capsids. In hemophilic mice injected with KP1-packaged recombinant AAV (rAAV) expressing the hyperactive FIX variant specific activity plasma levels were 10-fold or 2-fold enhanced when compared with wild-type or Padua huFIX injected mice, respectively. In rhesus macaques AAV-LK03 capsid outperformed AAV-KP1 in terms of antigen expression and liver transduction. Two animals from each group showed sustained low-level huFIX expression at 3 months after administration, while one animal from each group lost huFIX mRNA and protein expression over time, despite comparable vector copies. We investigated whether epigenetic differences in the vector episomes could explain this loss of transcription. Cut&Tag analysis revealed lower levels of activating histone marks in the two animals that lost expression. When comparing rAAV genome associated histone modifications in rhesus macaques with those in mice injected with the same vector, the activating histone marks were starkly decreased in macaque-derived episomes. Differential epigenetic marking of AAV genomes may explain different expression profiles in mice and rhesus macaques, as well as the wide dose response variation observed in primates in both preclinical and human clinical trials.

14.
Development ; 151(11)2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38682276

ABSTRACT

The GPR124/RECK/WNT7 pathway is an essential regulator of CNS angiogenesis and blood-brain barrier (BBB) function. GPR124, a brain endothelial adhesion seven-pass transmembrane protein, associates with RECK, which binds and stabilizes newly synthesized WNT7 that is transferred to frizzled (FZD) to initiate canonical ß-catenin signaling. GPR124 remains enigmatic: although its extracellular domain (ECD) is essential, the poorly conserved intracellular domain (ICD) appears to be variably required in mammals versus zebrafish, potentially via adaptor protein bridging of GPR124 and FZD ICDs. GPR124 ICD deletion impairs zebrafish angiogenesis, but paradoxically retains WNT7 signaling upon mammalian transfection. We thus investigated GPR124 ICD function using the mouse deletion mutant Gpr124ΔC. Despite inefficiently expressed GPR124ΔC protein, Gpr124ΔC/ΔC mice could be born with normal cerebral cortex angiogenesis, in comparison with Gpr124-/- embryonic lethality, forebrain avascularity and hemorrhage. Gpr124ΔC/ΔC vascular phenotypes were restricted to sporadic ganglionic eminence angiogenic defects, attributable to impaired GPR124ΔC protein expression. Furthermore, Gpr124ΔC and the recombinant GPR124 ECD rescued WNT7 signaling in culture upon brain endothelial Gpr124 knockdown. Thus, in mice, GPR124-regulated CNS forebrain angiogenesis and BBB function are exerted by ICD-independent functionality, extending the signaling mechanisms used by adhesion seven-pass transmembrane receptors.


Subject(s)
Blood-Brain Barrier , Brain , Neovascularization, Physiologic , Receptors, G-Protein-Coupled , Animals , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/embryology , Neovascularization, Physiologic/genetics , Receptors, G-Protein-Coupled/metabolism , Receptors, G-Protein-Coupled/genetics , Mice , Brain/metabolism , Brain/embryology , Protein Domains , Mice, Knockout , Signal Transduction , Wnt Proteins/metabolism , Wnt Proteins/genetics , Humans , Endothelial Cells/metabolism , Angiogenesis , GPI-Linked Proteins
15.
Anal Chem ; 96(19): 7444-7451, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38684052

ABSTRACT

Next-generation sequencing offers highly multiplexed and accurate detection of nucleic acid sequences but at the expense of complex workflows and high input requirements. The ease of use of CRISPR-Cas12 assays is attractive and may enable highly accurate detection of sequences implicated in, for example, cancer pathogenic variants. CRISPR assays often employ end-point measurements of Cas12 trans-cleavage activity after Cas12 activation by the target; however, end point-based methods can be limited in accuracy and robustness by arbitrary experimental choices. To overcome such limitations, we develop and demonstrate here an accurate assay targeting a mutation of the epidermal growth factor gene implicated in lung cancer (exon 19 deletion). The assay is based on characterizing the kinetics of Cas12 trans-cleavage to discriminate the mutant from wild-type targets. We performed extensive experiments (780 reactions) to calibrate key assay design parameters, including the guide RNA sequence, reporter sequence, reporter concentration, enzyme concentration, and DNA target type. Interestingly, we observed a competitive reaction between the target and reporter molecules that has important consequences for the design of CRISPR assays, which use preamplification to improve sensitivity. Finally, we demonstrate the assay on 18 tumor-extracted amplicons and 100 training iterations with 99% accuracy and discuss discrimination parameters and models to improve wild type versus mutant classification.


Subject(s)
Gene Deletion , Genes, erbB-1 , Genotyping Techniques , Genotyping Techniques/instrumentation , Genotyping Techniques/methods , Genotyping Techniques/standards , Genes, Reporter/genetics , Genes, erbB-1/genetics , Humans , RNA, Guide, CRISPR-Cas Systems/genetics , RNA, Guide, CRISPR-Cas Systems/metabolism , Lung Neoplasms/diagnosis , Lung Neoplasms/genetics , Reproducibility of Results
16.
Front Microbiol ; 15: 1357797, 2024.
Article in English | MEDLINE | ID: mdl-38463486

ABSTRACT

Plant microbiomes are known to serve several important functions for their host, and it is therefore important to understand their composition as well as the factors that may influence these microbial communities. The microbiome of Thalassia testudinum has only recently been explored, and studies to-date have primarily focused on characterizing the microbiome of plants in a single region. Here, we present the first characterization of the composition of the microbial communities of T. testudinum across a wide geographical range spanning three distinct regions with varying physicochemical conditions. We collected samples of leaves, roots, sediment, and water from six sites throughout the Atlantic Ocean, Caribbean Sea, and the Gulf of Mexico. We then analyzed these samples using 16S rRNA amplicon sequencing. We found that site and region can influence the microbial communities of T. testudinum, while maintaining a plant-associated core microbiome. A comprehensive comparison of available microbial community data from T. testudinum studies determined a core microbiome composed of 14 ASVs that consisted mostly of the family Rhodobacteraceae. The most abundant genera in the microbial communities included organisms with possible plant-beneficial functions, like plant-growth promoting taxa, disease suppressing taxa, and nitrogen fixers.

17.
J Invest Dermatol ; 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38520417

ABSTRACT

Intricate signaling systems are required to maintain homeostasis and promote differentiation in the epidermis. Receptor tyrosine kinases are central in orchestrating these systems in epidermal keratinocytes. In particular, EPHA2 and EGFR transduce distinct signals to dictate keratinocyte fate, yet how these cell communication networks are integrated has not been investigated. Our work shows that loss of EPHA2 impairs keratinocyte stratification, differentiation, and barrier function. To determine the mechanism of this dysfunction, we drew from our proteomics data of potential EPHA2 interacting proteins. We identified EGFR as a high-ranking EPHA2 interactor and subsequently validated this interaction. We found that when EPHA2 is reduced, EGFR activation and downstream signaling are intensified and sustained. Evidence indicates that prolonged SRC association contributes to the increase in EGFR signaling. We show that hyperactive EGFR signaling underlies the differentiation defect caused by EPHA2 knockdown because EGFR inhibition restores differentiation in EPHA2-deficient 3-dimensional skin organoids. Our data implicate a mechanism whereby EPHA2 restrains EGFR signaling, allowing for fine tuning in the processes of terminal differentiation and barrier formation. Taken together, we purport that crosstalk between receptor tyrosine kinases EPHA2 and EGFR is critical for epidermal differentiation.

18.
Nat Ecol Evol ; 8(4): 663-675, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38366132

ABSTRACT

Climate change is altering the functioning of foundational ecosystems. While the direct effects of warming are expected to influence individual species, the indirect effects of warming on species interactions remain poorly understood. In marine systems, as tropical herbivores undergo poleward range expansion, they may change food web structure and alter the functioning of key habitats. While this process ('tropicalization') has been documented within declining kelp forests, we have a limited understanding of how this process might unfold across other systems. Here we use a network of sites spanning 23° of latitude to explore the effects of increased herbivory (simulated via leaf clipping) on the structure of a foundational marine plant (turtlegrass). By working across its geographic range, we also show how gradients in light, temperature and nutrients modified plant responses. We found that turtlegrass near its northern boundary was increasingly affected (reduced productivity) by herbivory and that this response was driven by latitudinal gradients in light (low insolation at high latitudes). By contrast, low-latitude meadows tolerated herbivory due to high insolation which enhanced plant carbohydrates. We show that as herbivores undergo range expansion, turtlegrass meadows at their northern limit display reduced resilience and may be under threat of ecological collapse.


Subject(s)
Ecosystem , Herbivory , Food Chain , Forests , Climate Change , Plants
19.
Fam Community Health ; 47(2): 176-190, 2024.
Article in English | MEDLINE | ID: mdl-38372334

ABSTRACT

INTRODUCTION: The US Food and Drug Administration is poised to restrict the availability of menthol cigarettes and flavored cigars, products disproportionately used by Black/African American (B/AA) individuals. We examined B/AA youth and adult perceptions regarding factors contributing to tobacco use, as well as prevention/cessation resources. METHODS: In 2 mixed-methods studies in Richmond, Virginia, we conducted cross-sectional surveys among youth (n = 201) and adult (n = 212) individuals who were primarily B/AA and reported past 30-day cigar smoking or nontobacco use, followed by focus groups with a subset (youth: n = 30; adults: n = 24). Focus groups were analyzed using a thematic analysis framework, and descriptive survey data provided context to themes. RESULTS: Among focus group participants, 20% of youth and 75% of adults reported current cigar smoking. Six themes emerged across the groups: advertising/brands, sensory experiences, costs, social factors, youth-related factors, and dependence/cessation. Youth and adults perceived cigars as popular; cigar use was attributed to targeted advertising, flavors, affordability, and accessibility. While adults expressed concern regarding youth tobacco use, youth did not perceive tobacco prevention programs as helpful. Adults and youth reported limited access to community tobacco prevention/cessation programs. DISCUSSION: Expanded tobacco prevention and cessation resources for B/AA people who smoke could leverage federal regulatory actions to ban tobacco products targeted toward this group and decrease disparities in tobacco-related morbidity and mortality.


Subject(s)
Black or African American , Tobacco Use , Adult , Humans , Adolescent , Virginia , Cross-Sectional Studies , Surveys and Questionnaires
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