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1.
Pancreatology ; 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39095296

RESUMEN

Dysregulation of the epigenomic landscape of tumor cells has been implicated in the pathogenesis of pancreatic cancer. However, these alterations are not only restricted to neoplastic cells. The behavior of other cell populations in the tumor stroma such as cancer-associated fibroblasts, immune cells, and others are mostly regulated by epigenetic pathways. Here, we present an overview of the main cellular and acellular components of the pancreatic cancer tumor microenvironment and discuss how the epigenetic mechanisms operate at different levels in the stroma to establish a differential gene expression to regulate distinct cellular phenotypes contributing to pancreatic tumorigenesis.

2.
J Exp Clin Cancer Res ; 43(1): 214, 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39090759

RESUMEN

BACKGROUND: Melanoma progression is based on a close interaction between cancer cells and immune cells in the tumor microenvironment (TME). Thus, a better understanding of the mechanisms controlling TME dynamics and composition will help improve the management of this dismal disease. Work from our and other groups has reported the requirement of an active Hedgehog-GLI (HH-GLI) signaling for melanoma growth and stemness. However, the role of the downstream GLI1 transcription factor in melanoma TME remains largely unexplored. METHODS: The immune-modulatory activity of GLI1 was evaluated in a syngeneic B16F10 melanoma mouse model assessing immune populations by flow cytometry. Murine polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) were differentiated from bone marrow cells and their immunosuppressive ability was assessed by inhibition of T cells. Conditioned media (CM) from GLI1-overexpressing mouse melanoma cells was used to culture PMN-MDSCs, and the effects of CM were evaluated by Transwell invasion assay and T cell inhibition. Cytokine array analysis, qPCR and chromatin immunoprecipitation were performed to explore the regulation of CX3CL1 expression by GLI1. Human monocyte-derived dendritic cells (moDCs) were cultured in CM from GLI1-silenced patient-derived melanoma cells to assess their activation and recruitment. Blocking antibodies anti-CX3CL1, anti-CCL7 and anti-CXCL8 were used for in vitro functional assays. RESULTS: Melanoma cell-intrinsic activation of GLI1 promotes changes in the infiltration of immune cells, leading to accumulation of immunosuppressive PMN-MDSCs and regulatory T cells, and to decreased infiltration of dendric cells (DCs), CD8 + and CD4 + T cells in the TME. In addition, we show that ectopic expression of GLI1 in melanoma cells enables PMN-MDSC expansion and recruitment, and increases their ability to inhibit T cells. The chemokine CX3CL1, a direct transcriptional target of GLI1, contributes to PMN-MDSC expansion and recruitment. Finally, silencing of GLI1 in patient-derived melanoma cells promotes the activation of human monocyte-derived dendritic cells (moDCs), increasing cytoskeleton remodeling and invasion ability. This phenotype is partially prevented by blocking the chemokine CCL7, but not CXCL8. CONCLUSION: Our findings highlight the relevance of tumor-derived GLI1 in promoting an immune-suppressive TME, which allows melanoma cells to evade the immune system, and pave the way for the design of new combination treatments targeting GLI1.


Asunto(s)
Melanoma , Células Supresoras de Origen Mieloide , Microambiente Tumoral , Proteína con Dedos de Zinc GLI1 , Animales , Proteína con Dedos de Zinc GLI1/metabolismo , Proteína con Dedos de Zinc GLI1/genética , Ratones , Humanos , Células Supresoras de Origen Mieloide/metabolismo , Células Supresoras de Origen Mieloide/inmunología , Melanoma/patología , Melanoma/metabolismo , Melanoma/inmunología , Melanoma/genética , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Melanoma Experimental/metabolismo , Línea Celular Tumoral , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Ratones Endogámicos C57BL
3.
Lung Cancer ; 194: 107890, 2024 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-39003936

RESUMEN

INTRODUCTION: Histological confirmation of a lung tumor is the prerequisite for treatment planning. It has been suspected that CT-guided needle biopsy (CTGNB) exposes the patient to a higher risk of pleural recurrence. However, the distance between tumor and pleura has largely been neglected as a possible confounder when comparing CTGNB to bronchoscopy. METHODS: All patients with lung cancer histologically confirmed by bronchoscopy or CTGNB between 2010 and 2020 were enrolled and studied. Patients' medical histories, radiologic and pathologic findings and surgical records were reviewed. Pleural recurrence was diagnosed by pleural biopsy, fluid cytology, or by CT chest imaging showing progressive pleural nodules. RESULTS: In this retrospective unicenter analysis, 844 patients underwent curative resection for early-stage lung cancer between 2010 and 2020. Median follow-up was 47.5 months (3-137). 27 patients (3.2 %) with ipsilateral pleural recurrence (IPR) were identified. The distance of the tumor to the pleura was significantly smaller in patients who underwent CTGNB. A tendency of increased risk of IPR was observed in tumors located in the lower lobe (HR: 2.18 [±0.43], p = 0.068), but only microscopic pleural invasion was a significant independent predictive factor for increased risk of IPR (HR: 5.33 [± 0.51], p = 0.001) by multivariate cox analysis. Biopsy by CTGNB did not affect IPR (HR: 1.298 [± 0.39], p = 0.504). CONCLUSION: CTGNB is safe and not associated with an increased incidence of IPR in our cohort of patients. This observation remains to be validated in a larger multicenter patient cohort.

4.
J Clin Med ; 13(13)2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38999433

RESUMEN

Hepatitis C virus still represents a major cause of morbidity and mortality worldwide. In Peru, two national practice guidelines for the management of this infection were published more than 5 years ago; however, the latest breakthroughs in the treatment make it necessary to update these guidelines. We reviewed the most recent recommendations of the international guidelines and compared them with the current Peruvian guidelines. We found major differences, such as the use of Glecaprevir/Pibrentasvir as a first-line therapy, which is contemplated in the World Health Organization guideline, and recommended by American and European guidelines, but is not considered in the Peruvian guidelines. Another crucial difference lies in the management of patients with chronic kidney disease, who are treated nowadays with a variety of direct-acting antivirals, with no restrictions on the use of Sofosbuvir-based regimens in first-world countries, an approach that has not been adopted in Peru. We believe that standardization of the recommendations of the Peruvian guidelines is imperative, including the new therapeutic strategies that have emerged in recent years. We also suggest conducting a cost effectiveness analysis in the Peruvian context to allow for the implementation of new antivirals, and to achieve a better control of hepatitis C in the country.

5.
J Clin Med ; 13(13)2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38999546

RESUMEN

Background: For locally advanced rectal cancer, neoadjuvant therapy (NT) is an established element of therapy. Endoscopic vacuum therapy (EVT) has been a relevant treatment option for anastomotic leakage after rectal resection since 2008. The aim was to evaluate the influence of NT on the duration and success of EVT in anastomotic leakage after rectal resection for rectal cancer. Methods: This was a monocentric, retrospective cohort study including patients who underwent rectal resection with primary anastomosis because of histologically proven carcinoma of the rectum in the Department for General and Visceral Surgery of Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin over a period of ten years (2012 to 2022). Results: Overall, 243 patients were included, of which 47 patients (19.3%) suffered from anastomotic leakage grade B with consecutive EVT. A total of 29 (61.7%) patients received NT and 18 patients (38.3%) did not. The median duration of EVT until the removal of the sponge did not differ between patients with and without NT: 24.0 days (95% CI 6.44-41.56) versus 20.0 days (95% CI 17.03-22.97); p = 0.273. The median duration from insertion of EVT until complete healing was 74.0 days with NT (95% CI 10.07-137.93) versus 62.0 days without NT (95% CI 45.99-78.01); p = 0.490. Treatment failure-including early persistence and late onset of recurrent anastomotic leakage-was evident in 27.6% of patients with NT versus 27.8% without NT; p = 0.989. Ostomy was reversed in 19 patients (79.2%) with NT compared to 11 patients (68.8%) without NT; p = 0.456. Overall, continuity was restored in 75% of patients in the long term after EVT. Conclusion: This trial comprised-to our knowledge-the largest study cohort to analyze the outcome of EVT in anastomotic leakage after rectal resection for rectal cancer. We conclude that neoadjuvant therapy neither prolongs EVT nor the time to healing from anastomotic leakage. The rates of treatment failure of EVT and permanent ostomy were not higher when neoadjuvant therapy was used.

6.
Front Cell Infect Microbiol ; 14: 1409774, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39006741

RESUMEN

Background: Numerous bacteria are involved in the etiology of bacterial vaginosis (BV). Yet, current tests only focus on a select few. We therefore designed a new test targeting 22 BV-relevant species. Methods: Using 946 stored vaginal samples, a new qPCR test that quantitatively identifies 22 bacterial species was designed. The distribution and relative abundance of each species, α- and ß-diversities, correlation, and species co-existence were determined per sample. A diagnostic index was modeled from the data, trained, and tested to classify samples into BV-positive, BV-negative, or transitional BV. Results: The qPCR test identified all 22 targeted species with 95 - 100% sensitivity and specificity within 8 hours (from sample reception). Across most samples, Lactobacillus iners, Lactobacillus crispatus, Lactobacillus jensenii, Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae, Prevotella bivia, and Megasphaera sp. type 1 were relatively abundant. BVAB-1 was more abundant and distributed than BVAB-2 and BVAB-3. No Mycoplasma genitalium was found. The inter-sample similarity was very low, and correlations existed between key species, which were used to model, train, and test a diagnostic index: MDL-BV index. The MDL-BV index, using both species and relative abundance markers, classified samples into three vaginal microbiome states. Testing this index on our samples, 491 were BV-positive, 318 were BV-negative, and 137 were transitional BV. Although important differences in BV status were observed between different age groups, races, and pregnancy status, they were statistically insignificant. Conclusion: Using a diverse and large number of vaginal samples from different races and age groups, including pregnant women, the new qRT-PCR test and MDL-BV index efficiently diagnosed BV within 8 hours (from sample reception), using 22 BV-associated species.


Asunto(s)
Gardnerella vaginalis , Lactobacillus , Microbiota , Reacción en Cadena en Tiempo Real de la Polimerasa , Vagina , Vaginosis Bacteriana , Femenino , Vaginosis Bacteriana/diagnóstico , Vaginosis Bacteriana/microbiología , Humanos , Vagina/microbiología , Microbiota/genética , Lactobacillus/aislamiento & purificación , Lactobacillus/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Adulto , Gardnerella vaginalis/aislamiento & purificación , Gardnerella vaginalis/genética , Adulto Joven , Sensibilidad y Especificidad , Prevotella/aislamiento & purificación , Prevotella/genética , Megasphaera/aislamiento & purificación , Megasphaera/genética , Actinobacteria/aislamiento & purificación , Actinobacteria/genética , Actinobacteria/clasificación , Persona de Mediana Edad , Lactobacillus crispatus/aislamiento & purificación , Lactobacillus crispatus/genética , Adolescente , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/clasificación , Embarazo , ARN Ribosómico 16S/genética
7.
Drug Saf ; 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39009928

RESUMEN

BACKGROUND: Pregnant persons are susceptible to significant complications following COVID-19, even death. However, worldwide COVID-19 vaccination coverage during pregnancy remains suboptimal. OBJECTIVE: This study assessed the safety and effectiveness of COVID-19 vaccines administered to pregnant persons and shared this evidence via an interactive online website. METHODS: We followed Cochrane methods to conduct this living systematic review. We included studies assessing the effects of COVID-19 vaccines in pregnant persons. We conducted searches every other week for studies until October 2023, without restrictions on language or publication status, in ten databases, guidelines, preprint servers, and COVID-19 websites. The reference lists of eligible studies were hand searched to identify additional relevant studies. Pairs of review authors independently selected eligible studies using the web-based software COVIDENCE. Data extraction and risk of bias assessment were performed independently by pairs of authors. Disagreements were resolved by consensus. We performed random-effects meta-analyses of adjusted relative effects for relevant confounders of comparative studies and proportional meta-analyses to summarize frequencies from one-sample studies using R statistical software. We present the GRADE certainty of evidence from comparative studies. Findings are available on an interactive living systematic review webpage, including an updated evidence map and real-time meta-analyses customizable by subgroups and filters. RESULTS: We included 177 studies involving 638,791 participants from 41 countries. Among the 11 types of COVID-19 vaccines identified, the most frequently used platforms were mRNA (154 studies), viral vector (51), and inactivated virus vaccines (17). Low to very low-certainty evidence suggests that vaccination may result in minimal to no important differences compared to no vaccination in all assessed maternal and infant safety outcomes from 26 fewer to 17 more events per 1000 pregnant persons, and 13 fewer to 9 more events per 1000 neonates, respectively. We found statistically significant reductions in emergency cesarean deliveries (9%) with mRNA vaccines, and in stillbirth (75-83%) with mRNA/viral vector vaccines. Low to very low-certainty evidence suggests that vaccination during pregnancy with mRNA vaccines may reduce severe cases or hospitalizations in pregnant persons with COVID-19 (72%; 95% confidence interval [CI] 42-86), symptomatic COVID-19 (78%; 95% CI 21-94), and virologically confirmed SARS-CoV-2 infection (82%; 95% CI 39-95). Reductions were lower with other vaccine types and during Omicron variant dominance than Alpha and Delta dominance. Infants also presented with fewer severe cases or hospitalizations due to COVID-19 and laboratory-confirmed SARS-CoV-2 infection (64%; 95% CI 37-80 and 66%; 95% CI 37-81, respectively). CONCLUSIONS: We found a large body of evidence supporting the safety and effectiveness of COVID-19 vaccines during pregnancy. While the certainty of evidence is not high, it stands as the most reliable option available, given the current absence of pregnant individuals in clinical trials. Results are shared in near real time in an accessible and interactive format for scientists, decision makers, clinicians, and the general public. This living systematic review highlights the relevance of continuous vaccine safety and effectiveness monitoring, particularly in at-risk populations for COVID-19 impact such as pregnant persons, during the introduction of new vaccines. CLINICAL TRIAL REGISTRATION: PROSPERO: CRD42021281290.

8.
Ann Biomed Eng ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38969956

RESUMEN

As full-scale detailed hemodynamic simulations of the entire vasculature are not feasible, numerical analysis should be focused on specific regions of the cardiovascular system, which requires the identification of lumped parameters to represent the patient behavior outside the simulated computational domain. We present a novel technique for estimating cardiovascular model parameters using gappy Proper Orthogonal Decomposition (g-POD). A POD basis is constructed with FSI simulations for different values of the lumped model parameters, and a linear operator is applied to retain information that can be compared to the available patient measurements. Then, the POD coefficients of the reconstructed solution are computed either by projecting patient measurements or by solving a minimization problem with constraints. The POD reconstruction is then used to estimate the model parameters. In the first test case, the parameter values of a 3-element Windkessel model are approximated using artificial patient measurements, obtaining a relative error of less than 4.2%. In the second case, 4 sets of 3-element Windkessel are approximated in a patient's aorta geometry, resulting in an error of less than 8% for the flow and less than 5% for the pressure. The method shows accurate results even with noisy patient data. It automatically calculates the delay between measurements and simulations and has flexibility in the types of patient measurements that can handle (at specific points, spatial or time averaged). The method is easy to implement and can be used in simulations performed in general-purpose FSI software.

9.
Lancet Oncol ; 25(8): 1025-1037, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38976997

RESUMEN

BACKGROUND: Current guidelines recommend use of adjuvant imatinib therapy for many patients with gastrointestinal stromal tumours (GISTs); however, its optimal treatment duration is unknown and some patient groups do not benefit from the therapy. We aimed to apply state-of-the-art, interpretable artificial intelligence (ie, predictions or prescription logic that can be easily understood) methods on real-world data to establish which groups of patients with GISTs should receive adjuvant imatinib, its optimal treatment duration, and the benefits conferred by this therapy. METHODS: In this observational cohort study, we considered for inclusion all patients who underwent resection of primary, non-metastatic GISTs at the Memorial Sloan Kettering Cancer Center (MSKCC; New York, NY, USA) between Oct 1, 1982, and Dec 31, 2017, and who were classified as intermediate or high risk according to the Armed Forces Institute of Pathology Miettinen criteria and had complete follow-up data with no missing entries. A counterfactual random forest model, which used predictors of recurrence (mitotic count, tumour size, and tumour site) and imatinib duration to infer the probability of recurrence at 7 years for a given patient under each duration of imatinib treatment, was trained in the MSKCC cohort. Optimal policy trees (OPTs), a state-of-the-art interpretable AI-based method, were used to read the counterfactual random forest model by training a decision tree with the counterfactual predictions. The OPT recommendations were externally validated in two cohorts of patients from Poland (the Polish Clinical GIST Registry), who underwent GIST resection between Dec 1, 1981, and Dec 31, 2011, and from Spain (the Spanish Group for Research in Sarcomas), who underwent resection between Oct 1, 1987, and Jan 30, 2011. FINDINGS: Among 1007 patients who underwent GIST surgery in MSKCC, 117 were included in the internal cohort; for the external cohorts, the Polish cohort comprised 363 patients and the Spanish cohort comprised 239 patients. The OPT did not recommend imatinib for patients with GISTs of gastric origin measuring less than 15·9 cm with a mitotic count of less than 11·5 mitoses per 5 mm2 or for those with small GISTs (<5·4 cm) of any site with a count of less than 11·5 mitoses per 5 mm2. In this cohort, the OPT cutoffs had a sensitivity of 92·7% (95% CI 82·4-98·0) and a specificity of 33·9% (22·3-47·0). The application of these cutoffs in the two external cohorts would have spared 38 (29%) of 131 patients in the Spanish cohort and 44 (35%) of 126 patients in the Polish cohort from unnecessary treatment with imatinib. Meanwhile, the risk of undertreating patients in these cohorts was minimal (sensitivity 95·4% [95% CI 89·5-98·5] in the Spanish cohort and 92·4% [88·3-95·4] in the Polish cohort). The OPT tested 33 different durations of imatinib treatment (<5 years) and found that 5 years of treatment conferred the most benefit. INTERPRETATION: If the identified patient subgroups were applied in clinical practice, as many as a third of the current cohort of candidates who do not benefit from adjuvant imatinib would be encouraged to not receive imatinib, subsequently avoiding unnecessary toxicity on patients and financial strain on health-care systems. Our finding that 5 years is the optimal duration of imatinib treatment could be the best source of evidence to inform clinical practice until 2028, when a randomised controlled trial with the same aims is expected to report its findings. FUNDING: National Cancer Institute.


Asunto(s)
Inteligencia Artificial , Tumores del Estroma Gastrointestinal , Mesilato de Imatinib , Humanos , Tumores del Estroma Gastrointestinal/cirugía , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Tumores del Estroma Gastrointestinal/patología , Mesilato de Imatinib/uso terapéutico , Femenino , Masculino , Persona de Mediana Edad , Anciano , Antineoplásicos/uso terapéutico , Quimioterapia Adyuvante , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/tratamiento farmacológico , Neoplasias Gastrointestinales/cirugía , Neoplasias Gastrointestinales/tratamiento farmacológico , Neoplasias Gastrointestinales/patología , Adulto , Estudios de Cohortes , Resultado del Tratamiento
10.
Br J Surg ; 111(7)2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-39051667

RESUMEN

BACKGROUND: To date, only two studies have compared the outcomes of patients with liver-limited BRAF V600E-mutated colorectal liver metastases (CRLMs) managed with resection versus systemic therapy alone, and these have reported contradictory findings. METHODS: In this observational, international, multicentre study, patients with liver-limited BRAF V600E-mutated CRLMs treated with resection or systemic therapy alone were identified from institutional databases. Patterns of recurrence/progression and overall survival were compared using multivariable analyses of the entire cohort and a propensity score-matched cohort. RESULTS: Of 170 patients included, 119 underwent hepatectomy and 51 received systemic treatment. Surgically treated patients had a more favourable pattern of recurrence with most recurrences limited to a single site, whereas diffuse progression was more common among patients who received systemic treatment (19 versus 44%; P = 0.002). Surgically treated patients had longer median overall survival (35 versus 20 months; P < 0.001). Hepatectomy was independently associated with better OS than systemic treatment alone (HR 0.37, 95% c.i. 0.21 to 0.65). In the propensity score-matched cohort, surgically treated patients had longer median overall survival (28 versus 20 months; P < 0.001); hepatectomy was independently associated with better overall survival (HR 0.47, 0.25 to 0.88). CONCLUSION: BRAF V600E mutation should not be considered a contraindication to surgery for patients with resectable, liver-only CRLMs.


Asunto(s)
Neoplasias Colorrectales , Hepatectomía , Neoplasias Hepáticas , Proteínas Proto-Oncogénicas B-raf , Humanos , Neoplasias Hepáticas/secundario , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/cirugía , Neoplasias Hepáticas/mortalidad , Hepatectomía/métodos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Proteínas Proto-Oncogénicas B-raf/genética , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Anciano , Mutación , Puntaje de Propensión , Recurrencia Local de Neoplasia/genética , Adulto , Resultado del Tratamiento
11.
Phys Chem Chem Phys ; 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39083248

RESUMEN

Correction for 'Nonequilibrium thermodynamic model of thermoelectricity and thermodiffusion in semiconductors' by Semen N. Semenov et al., Phys. Chem. Chem. Phys., 2023, 25, 6790-6796, https://doi.org/10.1039/D2CP05065J.

12.
Nature ; 631(8022): 905-912, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39020174

RESUMEN

Microtubule function is modulated by the tubulin code, diverse posttranslational modifications that are altered dynamically by writer and eraser enzymes1. Glutamylation-the addition of branched (isopeptide-linked) glutamate chains-is the most evolutionarily widespread tubulin modification2. It is introduced by tubulin tyrosine ligase-like enzymes and erased by carboxypeptidases of the cytosolic carboxypeptidase (CCP) family1. Glutamylation homeostasis, achieved through the balance of writers and erasers, is critical for normal cell function3-9, and mutations in CCPs lead to human disease10-13. Here we report cryo-electron microscopy structures of the glutamylation eraser CCP5 in complex with the microtubule, and X-ray structures in complex with transition-state analogues. Combined with NMR analysis, these analyses show that CCP5 deforms the tubulin main chain into a unique turn that enables lock-and-key recognition of the branch glutamate in a cationic pocket that is unique to CCP family proteins. CCP5 binding of the sequences flanking the branch point primarily through peptide backbone atoms enables processing of diverse tubulin isotypes and non-tubulin substrates. Unexpectedly, CCP5 exhibits inefficient processing of an abundant ß-tubulin isotype in the brain. This work provides an atomistic view into glutamate branch recognition and resolution, and sheds light on homeostasis of the tubulin glutamylation syntax.


Asunto(s)
Carboxipeptidasas , Glutamatos , Microtúbulos , Tubulina (Proteína) , Animales , Humanos , Sitios de Unión , Encéfalo/metabolismo , Carboxipeptidasas/química , Carboxipeptidasas/metabolismo , Carboxipeptidasas/ultraestructura , Microscopía por Crioelectrón , Cristalografía por Rayos X , Glutamatos/metabolismo , Glutamatos/química , Homeostasis , Espectroscopía de Resonancia Magnética , Microtúbulos/química , Microtúbulos/metabolismo , Microtúbulos/ultraestructura , Modelos Moleculares , Unión Proteica , Células Sf9 , Especificidad por Sustrato , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/química , Tubulina (Proteína)/ultraestructura
13.
Front Med (Lausanne) ; 11: 1408623, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39026547

RESUMEN

Background: Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder that affects ~4% of the global population. ReFerm® is a postbiotic product derived from oat gruel fermented with Lactobacillus plantarum 299v, and it has been shown to have beneficial effects on intestinal permeability in patients with IBS. In this study, we investigated the effects of ReFerm® on regulators of intestinal permeability, namely mast cells and enteric glial cells. Materials and methods: A total of 30 patients with moderate to severe IBS were treated with an enema containing ReFerm® or a placebo twice daily. The patients underwent sigmoidoscopy with biopsies obtained from the distal colon at baseline and after 14 days of treatment. These biopsies were processed in two ways: some were fixed, embedded in paraffin, sectioned, and stained for mast cells and enteric glial cells; others were cryopreserved, lysed, and subjected to Western blotting to analyze the same markers. Results: Treatment with ReFerm®, but not the placebo, significantly reduced mast cell tryptase protein levels in the biopsy lysates. Although the number of mast cells remained unchanged in colonic biopsies, ReFerm® treatment significantly reduced mast cell degranulation, a result not observed in the placebo group. Neither ReFerm® or placebo treatment had an impact on total protein levels or the number of enteric glial cells in the biopsies. Conclusion: ReFerm® treatment significantly reduced both total mast cell tryptase levels and the degranulation of mast cells in colonic biopsies from patients with IBS, suggesting a decrease in mast cell activity as a potential mechanism underlying the beneficial effects of ReFerm®. However, further research is required to assess the molecular mechanisms through which ReFerm® operates in the colons of patients with IBS. Clinical trial registration: https://clinicaltrials.gov, identifier: NCT05475314.

14.
Phys Rev Lett ; 132(26): 268401, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38996302

RESUMEN

Common models of circadian rhythms are typically constructed as compartmental reactions of well-mixed biochemicals, incorporating a negative-feedback loop consisting of several intermediate reaction steps essentially required to produce oscillations. Spatial transport of each reactant is often represented as an extra compartmental reaction step. Contrary to this traditional understanding, in this Letter we demonstrate that a single activation-repression biochemical reaction pair is sufficient to generate sustained oscillations if the sites of both reactions are spatially separated and molecular transport is mediated by diffusion. Our proposed scenario represents the simplest configuration in terms of the participating chemical reactions and offers a conceptual basis for understanding biological oscillations and inspiring in vitro assays aimed at constructing minimal clocks.


Asunto(s)
Ritmo Circadiano , Modelos Biológicos , Difusión , Ritmo Circadiano/fisiología , Retroalimentación Fisiológica
15.
Biochem J ; 481(15): 983-997, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39078225

RESUMEN

Pancreatic cancer is a malignancy arising from the endocrine or exocrine compartment of this organ. Tumors from exocrine origin comprise over 90% of all pancreatic cancers diagnosed. Of these, pancreatic ductal adenocarcinoma (PDAC) is the most common histological subtype. The five-year survival rate for PDAC ranged between 5 and 9% for over four decades, and only recently saw a modest increase to ∼12-13%, making this a severe and lethal disease. Like other cancers, PDAC initiation stems from genetic changes. However, therapeutic targeting of PDAC genetic drivers has remained relatively unsuccessful, thus the focus in recent years has expanded to the non-genetic factors underlying the disease pathogenesis. Specifically, it has been proposed that dynamic changes in the epigenetic landscape promote tumor growth and metastasis. Emphasis has been given to the re-organization of enhancers, essential regulatory elements controlling oncogenic gene expression, commonly marked my histone 3 lysine 4 monomethylation (H3K4me1). H3K4me1 is typically deposited by histone lysine methyltransferases (KMTs). While well characterized as oncogenes in other cancer types, recent work has expanded the role of KMTs as tumor suppressor in pancreatic cancer. Here, we review the role and translational significance for PDAC development and therapeutics of KMTs.


Asunto(s)
Carcinoma Ductal Pancreático , N-Metiltransferasa de Histona-Lisina , Histonas , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patología , Histonas/metabolismo , Histonas/genética , Animales , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica
16.
Brain Behav Immun ; 121: 192-210, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39032542

RESUMEN

Cortical pathology involving inflammatory and neurodegenerative mechanisms is a hallmark of multiple sclerosis and a correlate of disease progression and cognitive decline. Astrocytes play a pivotal role in multiple sclerosis initiation and progression but astrocyte-neuronal network alterations contributing to gray matter pathology remain undefined. Here we unveil deregulation of astrocytic calcium signaling and astrocyte-to-neuron communication as key pathophysiological mechanisms of cortical dysfunction in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Using two-photon imaging ex vivo and fiber photometry in freely behaving mice, we found that acute EAE was associated with the emergence of spontaneously hyperactive cortical astrocytes exhibiting dysfunctional responses to cannabinoid, glutamate and purinoreceptor agonists. Abnormal astrocyte signaling by Gi and Gq protein coupled receptors was observed in the inflamed cortex. This was mirrored by treatments with pro-inflammatory factors both in vitro and ex vivo, suggesting cell-autonomous effects of the cortical neuroinflammatory environment. Finally, deregulated astrocyte calcium activity was associated with an enhancement of glutamatergic gliotransmission and a shift of astrocyte-mediated short-term and long-term plasticity mechanisms towards synaptic potentiation. Overall, our data identify astrocyte-neuronal network dysfunctions as key pathological features of gray matter inflammation in multiple sclerosis and potentially additional neuroimmunological disorders.

17.
Br J Pharmacol ; 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886096

RESUMEN

BACKGROUND AND PURPOSE: The cannabinoid CB1 receptor has a well-established role in appetite regulation. Drugs antagonizing central CB1 receptors, most notably rimonabant, induced weight loss and improved the metabolic profile in obese individuals but were discontinued due to psychiatric side effects. However, metabolic benefits were only partially attributable to weight loss, implying a role for peripheral receptors, and peripherally restricted CB1 receptor antagonists have since been of interest. Herein, we describe the evaluation of the peripherally restricted potent CB1 receptor inverse agonists TM38837 and TM39875, with acidic functionality, which were administered daily to diet-induced obese (DIO) mice for 5 weeks at doses for which CNS-mediated effects were minimal. EXPERIMENTAL APPROACH: Compounds were tested in dose-response in acute studies to compare efficacy (gastric transport) and extent of CNS exposure (hypothermia and satiety sequence) to demonstrate peripheral restriction and select doses for the subsequent chronic DIO study. KEY RESULTS: TM38837 but not TM39875 produced considerable (26%) weight loss, linked to a sustained reduction in food intake, together with improvements in plasma markers of inflammation and glucose homeostasis. Pharmacokinetic analysis indicated high plasma and low brain levels for both compounds with high liver levels for TM38837 (but not TM39875) due to hepatic uptake. CONCLUSION AND IMPLICATIONS: Weight loss and metabolic benefits of TM38837 are likely not CNS-mediated but could be linked to enhanced liver exposure, which implicates intracellular CB1 receptors in hepatocytes as a possible driver of obesity and co-morbidities.

18.
JCO Clin Cancer Inform ; 8: e2300184, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38900978

RESUMEN

PURPOSE: Prostate cancer (PCa) represents a highly heterogeneous disease that requires tools to assess oncologic risk and guide patient management and treatment planning. Current models are based on various clinical and pathologic parameters including Gleason grading, which suffers from a high interobserver variability. In this study, we determine whether objective machine learning (ML)-driven histopathology image analysis would aid us in better risk stratification of PCa. MATERIALS AND METHODS: We propose a deep learning, histopathology image-based risk stratification model that combines clinicopathologic data along with hematoxylin and eosin- and Ki-67-stained histopathology images. We train and test our model, using a five-fold cross-validation strategy, on a data set from 502 treatment-naïve PCa patients who underwent radical prostatectomy (RP) between 2000 and 2012. RESULTS: We used the concordance index as a measure to evaluate the performance of various risk stratification models. Our risk stratification model on the basis of convolutional neural networks demonstrated superior performance compared with Gleason grading and the Cancer of the Prostate Risk Assessment Post-Surgical risk stratification models. Using our model, 3.9% of the low-risk patients were correctly reclassified to be high-risk and 21.3% of the high-risk patients were correctly reclassified as low-risk. CONCLUSION: These findings highlight the importance of ML as an objective tool for histopathology image assessment and patient risk stratification. With further validation on large cohorts, the digital pathology risk classification we propose may be helpful in guiding administration of adjuvant therapy including radiotherapy after RP.


Asunto(s)
Aprendizaje Profundo , Clasificación del Tumor , Neoplasias de la Próstata , Humanos , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/cirugía , Masculino , Medición de Riesgo/métodos , Prostatectomía/métodos , Anciano , Persona de Mediana Edad , Procesamiento de Imagen Asistido por Computador/métodos
19.
Chin Clin Oncol ; 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38859602

RESUMEN

BACKGROUND: Patients with surgically resectable BRAF-mutated colorectal liver metastases (CRLM) or limited extrahepatic disease constitute a highly selective subgroup among BRAF-mutated patients, characterized by a more indolent disease biology. This is evident in their suitability for surgical resection. However, initial studies from a decade ago presented a discouraging outlook for these patients, citing early, frequent, multifocal recurrences and a very limited median overall survival (OS) of less than two years. Our objective was to provide an updated, comprehensive, and critically assessed review of the current literature on the prognostic impact of BRAF variants in CRLM, as well as to explore optimal treatment strategies for these patients through a systematic search. METHODS: A systematic literature search of the Medline, Scopus, and CENTRAL databases for studies reporting long-term outcomes of patients with a known BRAF status was performed. RESULTS: A total of 386 unique studies were screened during the study selection process. After applying the exclusion criteria, a total of 18 studies published between 2012 and 2023 were deemed eligible for inclusion. CONCLUSIONS: In contrast to older studies, more recent studies, with larger sample sizes, have revealed that the rate of extrahepatic recurrence is comparable between BRAF-mutated and wild-type patients. Furthermore, they have reported significantly improved survival outcomes, with OS extending up to 52 months. Notably, patients with non-V600E BRAF mutations may even achieve outcomes comparable to those with wild-type BRAF CRLM. Additionally, a few recent studies have compared surgery and systemic therapies, indicating that surgery is associated with improved survival rates, even for patients with the V600E mutation. This challenges the previous belief that BRAF mutations are absolute contraindications to surgical treatment. Surgical denial for technically resectable patients may now be reserved for specific clinical scenarios, such as the presence of a BRAF V600E mutation and concurrent extrahepatic disease.

20.
Pediatr Infect Dis J ; 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38916912

RESUMEN

Enterobacter cloacae cardiac implantable electronic device infections are rare but can be associated with significant morbidity and mortality. We report an 11-year-old female with Enterobacter cloacae infection of a dual-chamber transvenous pacemaker pocket. The report is supplemented by a comprehensive review of the literature on Enterobacter cloacae cardiac implantable electronic device infections.

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