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1.
Front Cell Dev Biol ; 12: 1390794, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39114570

RESUMEN

Introduction: Heparan sulfate (HS) in the vascular endothelial glycocalyx (eGC) is a critical regulator of blood vessel homeostasis. Trauma results in HS shedding from the eGC, but the impact of trauma on HS structural modifications that could influence mechanisms of vascular injury and repair has not been evaluated. Moreover, the effect of eGC HS shedding on endothelial cell (EC) homeostasis has not been fully elucidated. The objectives of this work were to characterize the impact of trauma on HS sulfation and determine the effect of eGC HS shedding on the transcriptional landscape of vascular ECs. Methods: Plasma was collected from 25 controls and 49 adults admitted to a level 1 trauma center at arrival and 24 h after hospitalization. Total levels of HS and angiopoietin-2, a marker of pathologic EC activation, were measured at each time point. Enzymatic activity of heparanase, the enzyme responsible for HS shedding, was determined in plasma from hospital arrival. Liquid chromatography-tandem mass spectrometry was used to characterize HS di-/tetrasaccharides in plasma. In vitro work was performed using flow conditioned primary human lung microvascular ECs treated with vehicle or heparinase III to simulate human heparanase activity. Bulk RNA sequencing was performed to determine differentially expressed gene-enriched pathways following heparinase III treatment. Results: We found that heparanase activity was increased in trauma plasma relative to controls, and HS levels at arrival were elevated in a manner proportional to injury severity. Di-/tetrasaccharide analysis revealed lower levels of 3-O-sulfated tetramers with a concomitant increase in ΔIIIS and ΔIIS disaccharides following trauma. Admission levels of total HS and specific HS sulfation motifs correlated with 24-h angiopoietin-2 levels, suggesting an association between HS shedding and persistent, pathological EC activation. In vitro pathway analysis demonstrated downregulation of genes that support cell junction integrity, EC polarity, and EC senescence while upregulating genes that promote cell differentiation and proliferation following HS shedding. Discussion: Taken together, our findings suggest that HS cleavage associated with eGC injury may disrupt homeostatic EC signaling and influence biosynthetic mechanisms governing eGC repair. These results require validation in larger, multicenter trauma populations coupled with in vivo EC-targeted transcriptomic and proteomic analyses.

2.
Front Res Metr Anal ; 9: 1418065, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39114810

RESUMEN

This commentary documents how federal funding agencies are changing the criteria by which they distribute taxpayer money intended for scientific research. Increasingly, STEMM (Science, Technology, Engineering, Mathematics, and Medicine) funding agencies are requiring applicants for funding to include a plan to advance DEI ("Diversity, Equity, and Inclusion") in their proposals and to dedicate a part of the research budget to its implementation. These mandates undermine the academic freedom of researchers and the unbiased generation of knowledge needed for a well-functioning democracy. Maintaining excellence in science is fundamental to the continuation of the U.S. as a global economic leader. Science provides a basis for solving important global challenges such as security, energy, climate, and health. Diverting funding from science into activities unrelated to the production of knowledge undermines science's ability to serve humankind. When funding agencies politicize science by using their power to further a particular ideological agenda, they contribute to public mistrust in science. Hijacking science funding to promote DEI is thus a threat to our society.

3.
Science ; 385(6709): 671-678, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-39116217

RESUMEN

Prymnesium parvum are harmful haptophyte algae that cause massive environmental fish kills. Their polyketide polyether toxins, the prymnesins, are among the largest nonpolymeric compounds in nature and have biosynthetic origins that have remained enigmatic for more than 40 years. In this work, we report the "PKZILLAs," massive P. parvum polyketide synthase (PKS) genes that have evaded previous detection. PKZILLA-1 and -2 encode giant protein products of 4.7 and 3.2 megadaltons that have 140 and 99 enzyme domains. Their predicted polyene product matches the proposed pre-prymnesin precursor of the 90-carbon-backbone A-type prymnesins. We further characterize the variant PKZILLA-B1, which is responsible for the shorter B-type analog prymnesin-B1, from P. parvum RCC3426 and thus establish a general model of haptophyte polyether biosynthetic logic. This work expands expectations of genetic and enzymatic size limits in biology.


Asunto(s)
Haptophyta , Toxinas Marinas , Sintasas Poliquetidas , Sintasas Poliquetidas/genética , Sintasas Poliquetidas/metabolismo , Toxinas Marinas/biosíntesis , Toxinas Marinas/metabolismo , Haptophyta/enzimología , Haptophyta/genética , Polienos/metabolismo , Polienos/química , Policétidos/metabolismo , Dominios Proteicos , Toxinas Poliéteres
4.
Am J Otolaryngol ; 45(6): 104483, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39116722

RESUMEN

OBJECTIVES: Investigate trends and associated factors in guideline adherence to adjuvant radiation therapy in locally advanced laryngeal and hypopharyngeal cancer after primary total laryngectomy (TL). METHODS: Previously untreated, non-metastatic patients who underwent TL for pathologic T4 larynx or hypopharynx squamous cell carcinoma (SCC) were queried using the National Cancer Database (NCDB). Patients were excluded if they had regional or distant metastasis or positive margins. Patient characteristics were evaluated for association with non-adherence to adjuvant radiation by logistic regression analysis. Association between non-adherence and overall survival (OS) was investigated by Cox proportional hazard analysis. RESULTS: Among 2823 eligible T4 N0 patients, 841 (29.8 %) did not receive adjuvant radiation. Associated factors include increasing age, a Charlson Comorbidity Index of 2, greater per-mile distance to treatment center, and treatment at an academic cancer center. Delivery of adjuvant radiation was associated with improved OS on multivariable (HR 0.82, 95 % CI 0.72-0.93) analysis. CONCLUSIONS: Within the NCDB, non-adherence to adjuvant radiation treatment after TL for pathologically T4 N0 larynx and hypopharynx SCC is common. Older patients with more comorbidities and greater travel distance may be at higher risk for non-adherence. Treatment at an academic cancer center is associated with non-adherence to recommended adjuvant radiation. Lack of adjuvant radiation is associated with worse overall survival.

5.
Eur Respir J ; 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39117429

RESUMEN

BACKGROUND: Recurrent respiratory tract infections (rRTIs) are a common reason for immunodiagnostic testing in children, which relies on serum antibody level measurements. However, because RTIs predominantly affect the respiratory mucosa, serum antibodies may inaccurately reflect local immune defences. We investigated antibody responses in saliva and their interplay with the respiratory microbiota in relation to RTI severity and burden in young children with rRTIs. METHODS: We conducted a prospective cohort study including 100 children aged <10 years with rRTIs, their family members, and healthy healthcare professionals. Total and polyreactive antibody concentrations were determined in serum and saliva (ELISA); respiratory microbiota composition (16S-rRNA-sequencing) and respiratory viruses (qPCR) were characterised in nasopharyngeal swabs. Proteomic analysis (Olink®) was performed on saliva and serum samples. RTI symptoms were monitored with a daily cell phone application and assessed using latent class analysis and negative binomial mixed models. RESULTS: Serum antibody levels were not associated with RTI severity. Strikingly, 28% of salivary antibodies and only 2% of serum antibodies displayed polyreactivity (p<0.001). Salivary polyreactive immunoglobulin A (IgA) was negatively associated with recurrent lower RTIs (aOR 0.80 [95% CI 0.67-0.94]) and detection of multiple respiratory viruses (aOR 0.76 [95% CI 0.61-0.96]). Haemophilus influenzae abundance was positively associated with RTI symptom burden (regression coefficient 0.07 [95% CI 0.02-0.12]). CONCLUSION: These results highlight the importance of mucosal immunity in RTI severity and burden and suggest that the level of salivary polyreactive IgA and H. influenzae abundance may serve as indicators of infection risk and severity in young children with rRTIs.

6.
Reprod Biol Endocrinol ; 22(1): 100, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39118090

RESUMEN

BACKGROUND: Patients with endometriosis suffer with chronic pelvic pain and infertility, and from the lack of pharmacologic therapies that consistently halt disease progression. Differences in the endometrium of patients with endometriosis vs. unaffected controls are well-documented. Specifically, shed endometrial tissues (delivered to the pelvic cavity via retrograde menstruation) reveal that a subset of stromal cells exhibiting pro-inflammatory, pro-fibrotic, and pro-senescence-like phenotypes is enhanced in endometriosis patients compared to controls. Additionally, cultured biopsy-derived endometrial stromal cells from endometriosis patients exhibit impaired decidualization, a defined differentiation process required for human embryo implantation and pregnancy. Quercetin, a senolytic agent, shows therapeutic potential for pulmonary fibrosis, a disorder attributed to senescent pulmonary fibroblasts. In rodent models of endometriosis, quercetin shows promise, and quercetin improves decidualization in vitro. However, the exact mechanisms are not completely understood. Therefore, we investigated the effects of quercetin on menstrual effluent-derived endometrial stromal cells from endometriosis patients and unaffected controls to define the signaling pathways underlying quercetin's effects on endometrial stromal cells. METHODS: Menstrual effluent-derived endometrial stromal cells were collected and cultured from unaffected controls and endometriosis patients and then, low passage cells were treated with quercetin (25 µM) under basal or standard decidualization conditions. Decidualization responses were analyzed by measuring the production of IGFBP1 and PRL. Also, the effects of quercetin on intracellular cAMP levels and cellular oxidative stress responses were measured. Phosphokinase arrays, western blotting, and flow cytometry methods were performed to define the effects of quercetin on various signaling pathways and the potential mechanistic roles of quercetin. RESULTS: Quercetin significantly promotes decidualization of control- and endometriosis-endometrial stromal cells. Quercetin substantially reduces the phosphorylation of multiple signaling molecules in the AKT and ERK1/2 pathways, while enhancing the phosphorylation of p53 and total p53 levels. Furthermore, p53 inhibition blocks decidualization while p53 activation promotes decidualization. Finally, we provide evidence that quercetin increases apoptosis of endometrial stromal cells with a senescent-like phenotype. CONCLUSIONS: These data provide insight into the mechanisms of action of quercetin on endometrial stromal cells and warrant future clinical trials to test quercetin and other senolytics for treating endometriosis.


Asunto(s)
Senescencia Celular , Endometriosis , Proteínas Proto-Oncogénicas c-akt , Quercetina , Células del Estroma , Proteína p53 Supresora de Tumor , Quercetina/farmacología , Femenino , Humanos , Endometriosis/metabolismo , Endometriosis/patología , Endometriosis/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Adulto , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo , Senescencia Celular/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismo , Endometrio/efectos de los fármacos , Endometrio/metabolismo , Endometrio/patología , Decidua/efectos de los fármacos , Decidua/metabolismo , Transducción de Señal/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Células Cultivadas
7.
Nat Med ; 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39112795

RESUMEN

Clinical trials in metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis) require histologic scoring for assessment of inclusion criteria and endpoints. However, variability in interpretation has impacted clinical trial outcomes. We developed an artificial intelligence-based measurement (AIM) tool for scoring MASH histology (AIM-MASH). AIM-MASH predictions for MASH Clinical Research Network necroinflammation grades and fibrosis stages were reproducible (κ = 1) and aligned with expert pathologist consensus scores (κ = 0.62-0.74). The AIM-MASH versus consensus agreements were comparable to average pathologists for MASH Clinical Research Network scores (82% versus 81%) and fibrosis (97% versus 96%). Continuous scores produced by AIM-MASH for key histological features of MASH correlated with mean pathologist scores and noninvasive biomarkers and strongly predicted progression-free survival in patients with stage 3 (P < 0.0001) and stage 4 (P = 0.03) fibrosis. In a retrospective analysis of the ATLAS trial (NCT03449446), responders receiving study treatment showed a greater continuous change in fibrosis compared with placebo (P = 0.02). Overall, these results suggest that AIM-MASH may assist pathologists in histologic review of MASH clinical trials, reducing inter-rater variability on trial outcomes and offering a more sensitive and reproducible measure of patient responses.

9.
Surv Ophthalmol ; 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39097172

RESUMEN

We provide an overview of the expanding literature on the role of cytokines and immune mediators in pathophysiology of age-related macular degeneration (AMD). Although many immunological mediators have been linked to AMD pathophysiology, the broader mechanistic picture remains unclear with substantial variations in the levels of evidence supporting these mediators. Therefore, we reviewed the literature considering the varying levels of supporting evidence. A Medical Subject Headings (MeSH) term-based literature research was conducted in September, 2023, consisting of the MeSH terms "cytokine" and "Age-related macular degeneration" connected by the operator "AND". After screening the publications by title, abstract, and full text, a total of 146 publications were included. The proinflammatory cytokines IL-1ß (especially in basic research studies), IL-6, IL-8, IL-18, TNF-α, and MCP-1 are the most extensively characterised cytokines/chemokines, highlighting the role of local inflammasome activation and altered macrophage function in the AMD pathophysiology. Among the antiinflammatory mediators IL-4, IL-10, and TGF-ß were found to be the most extensively characterised, with IL-4 driving and IL-10 and TGF-ß suppressing disease progression. Despite the extensive literature on this topic, a profound understanding of AMD pathophysiology has not yet been achieved. Therefore, further studies are needed identifying potential therapeutic targets, followed by clinical studies.

10.
Oecologia ; 2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39097560

RESUMEN

Organismal invasions have repeatedly been cited as a driving force behind the loss of biodiversity. Unlike many other impacts of invasion, the effect of invasion on native symbiont communities has received less attention. The introduction of invasive hosts presents a potential opportunity to native symbionts; invasive hosts could benefit native symbionts through providing a novel host environment that improves symbiont fitness relative to their fitness on native hosts. Alternatively, invasive hosts could noncompetent hosts for native symbionts, resulting in negative impacts on native symbiont abundance and diversity. Crayfish in the northern hemisphere host diverse assemblages of obligate annelid symbionts (P: Anellida, O: Branchiobdellida). Two invasive crayfish hosts in the genus Faxonius have been introduced and are interacting with the native crayfish hosts and their symbionts in three watersheds in western Virginia, USA. Previous studies suggest that the invasive host F. cristavarius is a less competent host for symbionts compared to native hosts in the genus Cambarus. We carried out an extensive survey in these watersheds to determine impacts of varying degrees of invasion on branchiobdellidan abundance and diversity. We also conducted a complementary host replacement experiment to investigate how increases in the relative abundance of invasive hosts contributes to observed patterns of symbiont abundance and diversity in the field. In our survey, as the proportion of invasive hosts at a site increased, branchiobdellidan abundance and diversity declined significantly. In the experiment, the worms dispersed onto both native and invasive hosts. As the percentage of noncompetent F. cristavarius hosts increased, the survival of branchiobdellidans declined. Both symbiont survival and opportunities for successful dispersal are reduced as this noncompetent invasive host progressively displaces native hosts, which imperils the integrity of native host-symbiont systems. Given that many native hosts accrue significant fitness benefits from their relationships with native symbionts, including hosts in our study system, losses of beneficial symbionts may produce a positive feedback loop that decreases invasion resistance of native species, exacerbates the effects of invasions, and presents a major conservation issue in invaded systems.

11.
J Int Med Res ; 52(8): 3000605241264799, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39102503

RESUMEN

OBJECTIVES: Nasogastric tube use can lead to pressure injury. Some nasogastric tube securement devices (NG-SD) include hard plastic components. In the current study, we assessed the differences in strain profiles for two NG-SD, one with hard segments and one without hard segments, using finite element analysis (FEA) to measure strain and deformation occurring at the nasogastric tube-tissue interface. METHODS: FEA in silico models of devices were based on device mechanical test data and clinically relevant placements. Peak strain values were determined by modelling different scenarios using Abaqus software whereby the tubing is moved during wear. RESULTS: The modelling showed peak strains ranging from 52% to 434% for the two NG-SD depending on the tubing placement and device type. Peak strain was always higher for the hard plastic device. Tissue strain energy was a minimum of 133.8 mJ for the NG-SD with no hard parts and a maximum of 311.6 mJ for the NG-SD with hard parts. CONCLUSIONS: This study provided evidence through in silico modelling that NG-SD without hard components may impart less strain and stress to tissues which may provide an option for tube securement that is less likely to cause medical device-related pressure injury.


Asunto(s)
Simulación por Computador , Análisis de Elementos Finitos , Intubación Gastrointestinal , Intubación Gastrointestinal/instrumentación , Intubación Gastrointestinal/métodos , Intubación Gastrointestinal/efectos adversos , Humanos , Estrés Mecánico
12.
Front Endocrinol (Lausanne) ; 15: 1432928, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39104812

RESUMEN

We recently reported that a novel chimeric peptide (GEP44) targeting both the glucagon-like peptide-1 receptor (GLP-1R) and neuropeptide Y1- and Y2 receptor (Y1R and Y2R) reduced energy intake and body weight (BW) in diet-induced obese (DIO) rats. We hypothesized that GEP44 reduces energy intake and BW primarily through a GLP-1R dependent mechanism. To test this hypothesis, GLP-1R+/+ mice and GLP-1R null (GLP-1R-/-) mice were fed a high fat diet for 4 months to elicit diet-induced obesity prior to undergoing a sequential 3-day vehicle period, 3-day drug treatment (5, 10, 20 or 50 nmol/kg; GEP44 vs the selective GLP-1R agonist, exendin-4) and a 3-day washout. Energy intake, BW, core temperature and activity were measured daily. GEP44 (10, 20 and 50 nmol/kg) reduced BW after 3-day treatment in DIO male GLP-1R+/+ mice by -1.5 ± 0.6, -1.3 ± 0.4 and -1.9 ± 0.4 grams, respectively (P<0.05), with similar effects being observed in female GLP-1R+/+ mice. These effects were absent in male and female DIO GLP-1R-/- mice suggesting that GLP-1R signaling contributes to GEP44-elicited reduction of BW. Further, GEP44 decreased energy intake in both male and female DIO GLP-1R+/+ mice, but GEP44 appeared to produce more consistent effects across multiple doses in males. In GLP-1R-/- mice, the effects of GEP44 on energy intake were only observed in males and not females, suggesting that GEP44 may reduce energy intake, in part, through a GLP-1R independent mechanism in males. In addition, GEP44 reduced core temperature and activity in both male and female GLP-1R+/+ mice suggesting that it may also reduce energy expenditure. Lastly, we show that GEP44 reduced fasting blood glucose in DIO male and female mice through GLP-1R. Together, these findings support the hypothesis that the chimeric peptide, GEP44, reduces energy intake, BW, core temperature, and glucose levels in male and female DIO mice primarily through a GLP-1R dependent mechanism.


Asunto(s)
Peso Corporal , Dieta Alta en Grasa , Ingestión de Energía , Receptor del Péptido 1 Similar al Glucagón , Ratones Obesos , Obesidad , Animales , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Femenino , Masculino , Ratones , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Dieta Alta en Grasa/efectos adversos , Ingestión de Energía/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Ratones Noqueados , Ratones Endogámicos C57BL
13.
Front Immunol ; 15: 1379175, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39086481

RESUMEN

Introduction: Intra-tumoral B cells mediate a plethora of immune effector mechanisms with key roles in anti-tumor immunity and serve as positive prognostic indicators in a variety of solid tumor types, including epithelial ovarian cancer (EOC). Several aspects of intra-tumoral B cells remain unclear, such as their state of activation, antigenic repertoires, and capacity to mature into plasma cells. Methods: B lymphocytes were isolated from primary EOC tissue and malignant ascites and were maintained in cell culture medium. The stably maintained cell lines were profiled with flow cytometry and B cell receptor sequencing. Secreted antibodies were tested with a human proteome array comprising more than 21,000 proteins, followed by ELISA for validation. Originating tumor samples were used for spatial profiling with chip cytometry. Results: Antibody-secreting B lymphocytes were isolated from the ovarian tumor microenvironment (TME) of four different EOC patients. The highly clonal cell populations underwent spontaneous immortalization in vitro, were stably maintained in an antibody-secreting state, and showed presence of Epstein-Barr viral (EBV) proteins. All originating tumors had high frequency of tumor-infiltrating B cells, present as lymphoid aggregates, or tertiary lymphoid structures. The antigens recognized by three of the four cell lines are coil-coil domain containing protein 155 (CCDC155), growth factor receptor-bound protein 2 (GRB2), and pyruvate dehydrogenase phosphatase2 (PDP2), respectively. Anti-CCDC155 circulating IgG antibodies were detected in 9 of 20 (45%) of EOC patients' sera. Tissue analyses with multiparameter chip cytometry shows that the antibodies secreted by these novel human B cell lines engage their cognate antigens on tumor cells. Discussion: These studies demonstrate that within the tumor-infiltrating lymphocyte population in EOC resides a low frequency population of antibody-secreting B cells that have been naturally exposed to EBV. Once stably maintained, these novel cell lines offer unique opportunities for future studies on intratumor B cell biology and new target antigen recognition, and for studies on EBV latency and/or viral reactivation in the TME of non-EBV related solid tumors such as the EOC.


Asunto(s)
Ascitis , Linfocitos B , Herpesvirus Humano 4 , Neoplasias Ováricas , Humanos , Femenino , Neoplasias Ováricas/inmunología , Herpesvirus Humano 4/inmunología , Linfocitos B/inmunología , Ascitis/inmunología , Infecciones por Virus de Epstein-Barr/inmunología , Latencia del Virus/inmunología , Microambiente Tumoral/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Carcinoma Epitelial de Ovario/inmunología , Anticuerpos Antivirales/inmunología , Línea Celular Tumoral
14.
Front Microbiol ; 15: 1437572, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39086644

RESUMEN

Introduction: The oral trichomonad Trichomonas tenax is increasingly appreciated as a likely contributor to periodontitis, a chronic inflammatory disease induced by dysbiotic microbiota, in humans and domestic animals and is strongly associated with its worst prognosis. Our current understanding of the molecular basis of T. tenax interactions with host cells and the microbiota of the oral cavity are still rather limited. One laboratory strain of T. tenax (Hs-4:NIH/ATCC 30207) can be grown axenically and two draft genome assemblies have been published for that strain, although the structural and functional annotation of these genomes is not available. Methods: GenSAS and Galaxy were used to annotate two publicly available draft genomes for T. tenax, with a focus on protein-coding genes. A custom pipeline was used to annotate the CAZymes for T. tenax and the human sexually transmitted parasite Trichomonas vaginalis, the most well-characterized trichomonad. A combination of bioinformatics analyses was used to screen for homologs of T. vaginalis virulence and colonization factors within the T. tenax annotated proteins. Results: Our annotation of the two T. tenax draft genome sequences and their comparison with T. vaginalis proteins provide evidence for several candidate virulence factors. These include candidate surface proteins, secreted proteins and enzymes mediating potential interactions with host cells and/or members of the oral microbiota. The CAZymes annotation identified a broad range of glycoside hydrolase (GH) families, with the majority of these being shared between the two Trichomonas species. Discussion: The presence of candidate T. tenax virulence genes supports the hypothesis that this species is associated with periodontitis through direct and indirect mechanisms. Notably, several GH proteins could represent potential new virulence factors for both Trichomonas species. These data support a model where T. tenax interactions with host cells and members of the oral microbiota could synergistically contribute to the damaging inflammation characteristic of periodontitis, supporting a causal link between T. tenax and periodontitis.

15.
New Phytol ; 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39101264

RESUMEN

In severely phosphorus (P)-impoverished environments, plants have evolved to use P very efficiently. Yet, it is unclear how P allocation in leaves contributes to their photosynthetic P-use efficiency (PPUE) and position along the leaf economics spectrum (LES). We address this question in 10 species of Banksia and Hakea, two highly P-efficient Proteaceae genera. We characterised traits in leaves of Banksia and Hakea associated with the LES: leaf mass per area, light-saturated photosynthetic rates, P and nitrogen concentrations, and PPUE. We also determined leaf P partitioning to five biochemical fractions (lipid, nucleic acid, metabolite, inorganic and residual P) and their possible association with the LES. For both genera, PPUE was negatively correlated with fractional allocation of P to lipids, but positively correlated with that to metabolites. For Banksia only, PPUE was negatively correlated with residual P, highlighting a strategy contrasting to that of Hakea. Phosphorus-allocation patterns significantly explained PPUE but were not linked to the resource acquisition vs resource conservation gradient defined by the LES. We conclude that distinct P-allocation patterns enable species from different genera to achieve high PPUE and discuss the implications of different P investments. We surmise that different LES axes representing different ecological strategies coexist in extremely P-impoverished environments.

16.
Nat Commun ; 15(1): 6597, 2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39097586

RESUMEN

Cyclin-dependent kinase 7 (Cdk7) is required in cell-cycle and transcriptional regulation owing to its function as both a CDK-activating kinase (CAK) and part of transcription factor TFIIH. Cdk7 forms active complexes by associating with Cyclin H and Mat1, and is regulated by two phosphorylations in the activation segment (T loop): the canonical activating modification at T170 and another at S164. Here we report the crystal structure of the human Cdk7/Cyclin H/Mat1 complex containing both T-loop phosphorylations. Whereas pT170 coordinates basic residues conserved in other CDKs, pS164 nucleates an arginine network unique to the ternary Cdk7 complex, involving all three subunits. We identify differential dependencies of kinase activity and substrate recognition on the individual phosphorylations. CAK function is unaffected by T-loop phosphorylation, whereas activity towards non-CDK substrates is increased several-fold by T170 phosphorylation. Moreover, dual T-loop phosphorylation stimulates multisite phosphorylation of the RNA polymerase II (RNAPII) carboxy-terminal domain (CTD) and SPT5 carboxy-terminal repeat (CTR) region. In human cells, Cdk7 activation is a two-step process wherein S164 phosphorylation precedes, and may prime, T170 phosphorylation. Thus, dual T-loop phosphorylation can regulate Cdk7 through multiple mechanisms, with pS164 supporting tripartite complex formation and possibly influencing processivity, while pT170 enhances activity towards key transcriptional substrates.


Asunto(s)
Quinasa Activadora de Quinasas Ciclina-Dependientes , Quinasas Ciclina-Dependientes , Fosforilación , Humanos , Quinasas Ciclina-Dependientes/metabolismo , Quinasas Ciclina-Dependientes/química , Quinasas Ciclina-Dependientes/genética , Ciclina H/metabolismo , Ciclina H/química , Ciclina H/genética , Cristalografía por Rayos X , ARN Polimerasa II/metabolismo , ARN Polimerasa II/química , Factor de Transcripción TFIIH/metabolismo , Factor de Transcripción TFIIH/química , Factor de Transcripción TFIIH/genética , Modelos Moleculares , Factores de Transcripción/metabolismo , Factores de Transcripción/química , Factores de Transcripción/genética , Dominios Proteicos , Proteínas de Ciclo Celular
17.
Artículo en Inglés | MEDLINE | ID: mdl-39111364

RESUMEN

BACKGROUND: Studies have shown an association between chronic rhinosinusitis (CRS) and non-cystic fibrosis (CF) bronchiectasis. OBJECTIVE: We aimed to determine if CRS increases the risk of developing non-CF bronchiectasis. METHODS: A retrospective analysis was conducted utilizing electronic medical records from an academic center. Patients with CRS without bronchiectasis, with at least one chest computed tomography (CT) performed after the diagnosis of CRS, were identified between January 2006 and December 2015. Charts were reviewed until May 2022. The control group was age, sex, and race matched, and included patients without CRS, asthma, or chronic obstructive pulmonary disease (COPD) who had at least one chest CT. Bronchiectasis was identified by chest CT radiology reports. The odds of developing bronchiectasis were analyzed in patients with CRS without asthma or COPD (Cohort 1) and patients with CRS with asthma or COPD (Cohort 2). RESULTS: The odds of developing bronchiectasis were significantly higher in patients with CRS (139/1594, 8.7%) compared to patients in the control group (443/7992 [5.5%], OR 1.63 [1.34-1.99]). Furthermore, the odds of developing bronchiectasis were higher in Cohort 1 (63/863 [7.3%], OR 1.34 [1.02-1.76]) and Cohort 2 (76/731 [10.4%], OR 1.98 [1.53-2.55]) versus the control group. After adjusting for confounding diseases, the association was attenuated in Cohort 1 (OR 1.22 [0.92-1.61]) but remained significant in Cohort 2 (OR 1.78 [1.37-2.31]). CONCLUSIONS: CRS is associated with the future development of non-CF bronchiectasis. Patients with CRS, especially those with asthma or COPD, have a higher likelihood of developing bronchiectasis than patients without CRS.

18.
J Thorac Oncol ; 19(8): 1155-1163, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39112003

RESUMEN

Worldwide, lung cancer is the most common killer among cancers, advanced disease has worse outcomes, earlier stage detection leads to better outcomes, and high-quality screening has a favorable net benefit. With the mortality reduction recognized from annual low-radiation dose computed tomography by screening those at high risk, there has been consideration that this benefit could translate to those who have never smoked. There have been several large-scale, single-arm, observational trials in Asia in persons with light to no smoking histories, with or without a family history of lung cancer, which have revealed high or higher lung cancer detection rates than previously reported in high-risk persons who currently or formerly smoked. The Early Detection Program for Lung Cancer in Taiwan, of nearly 50,000 persons, revealed that the cancer detection rate for those screened with low-radiation dose computed tomography was more than twofold higher in light- or never-smokers with a family history of lung cancer compared with high-risk persons with more than 30 or more pack-years exposure and meeting U.S. Preventative Services Task Force criteria for screening. In addition, more than 90% of the cancers detected in those with a family history were in early stage. On the basis of those findings, the researchers concluded that screening first-degree relatives of those with a family history of lung cancer, irrespective of smoking history, would lead to a decrease in lung cancer mortality. We believe that the findings in this cohort and others like it represent substantial overdiagnosis and that the harms associated with screening a population that has a low likelihood of developing lethal cancers have not been thoroughly considered. Here, we provide our perspective and consider the potential benefits and harms of screening populations outside those currently eligible using the U.S. Preventative Services Task Force criteria.


Asunto(s)
Detección Precoz del Cáncer , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patología , Detección Precoz del Cáncer/métodos , Factores de Riesgo , Tomografía Computarizada por Rayos X/métodos , Tamizaje Masivo/métodos
19.
Nat Med ; 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39107561

RESUMEN

Clonal hematopoiesis of indeterminate potential (CHIP) has been associated with an increased risk of cardiovascular (CV) disease in the general population. Currently, it is unclear whether this association is observed in large clinical trial cohorts with a high burden of existing CV disease or whether CV therapies can mitigate CHIP-associated CV risk. To address these questions, we studied 63,700 patients from five randomized trials that tested established therapies for CV disease, including treatments targeting the proteins PCSK9, SGLT2, P2Y12 and FXa. During a median follow-up of 2.5 years, 7,453 patients had at least one CV event (CV death, myocardial infarction (MI), ischemic stroke or coronary revascularization). The adjusted hazard ratio (aHR) for CV events for CHIP+ patients was 1.07 (95% CI: 0.99-1.16, P = 0.08), with consistent risk estimates across each component of CV risk. Significant heterogeneity in the risk of MI was observed, such that CHIP+ patients had a 30% increased risk of first MI (aHR = 1.31 (1.05-1.64), P = 0.02) but no increased risk of recurrent MI (aHR = 0.94 (0.79-1.13), Pint = 0.008), as compared to CHIP- patients. Moreover, no significant heterogeneity in treatment effect between individuals with and without CHIP was observed for any of the therapies studied in the five trials. These results indicate that in clinical trial populations, CHIP is associated with incident but not recurrent coronary events and that the presence of CHIP does not appear to identify patients who will derive greater benefit from commonly used CV therapies.

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