245 research outputs found
Radiation recall pneumonitis induced by chemotherapy after thoracic radiotherapy for lung cancer
<p>Abstract</p> <p>Background</p> <p>Radiation recall pneumonitis (RRP) describes a rare reaction in previously irradiated area of pulmonary tissue after application of triggering agents. RRP remains loosely characterized and poorly understood since it has so far only been depicted in 8 cases in the literature. The objective of the study is to disclose the general characteristics of RRP induced by chemotherapy after thoracic irradiation for lung cancer, and to draw attention to the potential toxicity even after a long time interval from the previous irradiation.</p> <p>Methods</p> <p>Medical records were reviewed. RRP induced by chemotherapy was diagnosed by the history of chemotherapy after radiotherapy, clinical presentation and radiographic abnormalities including ground-glass opacity, attenuation, or consolidation changes within the radiation field, plus that radiographic examination of the thorax before showed no radiation pneumonitis. RRP was graded according to Common Terminology Criteria for Adverse Events version 3.0. The characteristics of the 12 RRP cases were analyzed.</p> <p>Results</p> <p>Twelve patients were diagnosed of RRP, of who 8 received taxanes. The median time interval between end of radiotherapy and RRP, between end of radiotherapy and beginning of chemotherapy, and between beginning of chemotherapy and RRP was 95 days, 42 days and 47 days, respectively. Marked symptomatic and radiographic improvement was observed in the 12 patients after withdrawal of chemotherapy and application of systemic corticosteroids. Seven patients were rechallenged with chemotherapy, of whom four with the same kind of agents, and showed no recurrence with steroid cover.</p> <p>Conclusions</p> <p>Doctors should pay attention to RRP even after a long time from the previous radiotherapy or after several cycles of consolidation chemotherapy. Taxanes are likely to be associated with radiation recall more frequently. Withdrawal of causative agent and application of steroids are the treatment of choice. Patients may be rechallenged safely with steroid cover and careful observation, which needs to be validated.</p
Characteristics of vegetation carbon sink carrying capacity and restoration potential of China in recent 40 years
Improving vegetation carbon sink is a key measure for China to achieve the goal of carbon neutrality. However, the gradual saturation of vegetation carbon fixation under the constraints of climate change and human activities has limited the long-term and sustainable growth of vegetation carbon sinks, resulting in significant uncertainty in understanding future carbon sink capacity and recovery potential. In this study, NPP has been selected as a carbon sink indicator to quantitatively evaluated the carbon sink carrying capacity (CSCC) and the carbon sink resilience (CSR) of China. Results demonstrated that (1) the NPP of vegetation cover areas in China exhibited an increasing trend from 1981 to 2018, with an average growth rate of 1.66 g C m−2 yr.−1 and a total net NPP increase of 0.32 P g C. (2) The average CSCC in China was 658.59 g C m−2 yr.−1, with a total amount of 4.13 Pg C yr.−1. The NPP exceeded 60% of CSCC in various years, and the total NPP in 2018 was 3.26 Pg C yr.−1, which reached 78.74% of CSCC. In the future, carbon sink that can be increased is 0.88 Pg C yr.−1, with an increase proportion of 21.26%. (3) From 2000 to 2018, the NPP of vegetation-covered area (VCA) in China had generally maintained a positive succession trend with the stronger CSR. Only four provinces (HUN, CQ, AH, and JS) in China showed the extremely strong levels of CSR. The study has revealed the huge and sustainable CSCC and restoration potential in China over the past 40 years, and has provided spatial positioning and theoretical guidance for future ecological carbon sink restoration and benefit assessment
Accelerating Discovery of Novel and Bioactive Ligands With Pharmacophore-Informed Generative Models
Deep generative models have gained significant advancements to accelerate
drug discovery by generating bioactive chemicals against desired targets.
Nevertheless, most generated compounds that have been validated for potent
bioactivity often exhibit structural novelty levels that fall short of
satisfaction, thereby providing limited inspiration to human medicinal
chemists. The challenge faced by generative models lies in their ability to
produce compounds that are both bioactive and novel, rather than merely making
minor modifications to known actives present in the training set. Recognizing
the utility of pharmacophores in facilitating scaffold hopping, we developed
TransPharmer, an innovative generative model that integrates ligand-based
interpretable pharmacophore fingerprints with generative pre-training
transformer (GPT) for de novo molecule generation. TransPharmer demonstrates
superior performance across tasks involving unconditioned distribution
learning, de novo generation and scaffold elaboration under pharmacophoric
constraints. Its distinct exploration mode within the local chemical space
renders it particularly useful for scaffold hopping, producing compounds that
are structurally novel while pharmaceutically related. The efficacy of
TransPharmer is validated through two case studies involving the dopamine
receptor D2 (DRD2) and polo-like kinase 1 (PLK1). Notably in the case of PLK1,
three out of four synthesized designed compounds exhibit submicromolar
activities, with the most potent one, IIP0943, demonstrating a potency of 5.1
nM. Featuring a new scaffold of 4-(benzo[b]thiophen-7-yloxy)pyrimidine, IIP0943
also exhibits high selectivity for PLK1. It was demonstrated that TransPharmer
is a powerful tool for discovery of novel and bioactive ligands
New sedimentary evidence reveals a unique history of C4 biomass in continental East Asia since the early Miocene
Pyrogenic carbon (PyC) and n-alkane data from sediments in the northern South China Sea reveal variations in material from C4 plants in East Asia over the last ~19 Ma. These data indicate the likely presence of C4 taxa during the earliest part of the record analysed, with C4 species also prominent during the mid and late Miocene and especially the mid Quaternary. Notably the two records diverge after the mid Quaternary, when PyC data indicate a reduced contribution of C4 taxa to biomass burning, whereas plant-derived n-alkanes indicate a greater abundance of C4 plants. This divergence likely re ects di erences in the predominant source areas of organic materials accumulating at the coring site, with PyC representing a larger source area that includes material transported in the atmosphere from more temperate (relatively cooler and drier) parts of East Asia. Variations in the relative abundances of C3 and C4 taxa appear to be linked to a combination of environmental factors that have varied temporally and geographically and that are unique to East Asia. A major expansion of C4 biomass in warmer subtropical parts of eastern Asia from ~1 Ma and particularly from ~0.4 Ma is later than other parts of the world
Metastasis of human gastric adenocarcinoma partly depends on phosphoinositide-specific phospholipase γ1 expression
It is known that phosphoinositide-specific phospholipases γ1(PLCγ1) can trigger several signalling pathways to regulate cell proliferation, differentiation, and metastasis. However, whether this kinase is highly expressive and active in human gastric adenocarcinomas, and whether it can play an important role in the development of the cancer, have not yet been investigated. The aim of the study was to investigate the expression of PLCγ1 in human gastric adenocarcinoma, while the question of whether PLCγ1 can be activated through protein kinase B (Akt) signalling pathways to regulate cell migration was further explored using human gastric adenocarcinoma BGC-823 cell line. The expression of PLCγ1 in human adenocarcinoma was detected using immunohistochemical staining. The BGC-823 cells were cultured and treated with inhibitors or transfected with plasmid construction. The cell migration of BGC-823 cells was measured with wound healing assay, cell migration assay, and the ruffling assay. The expression levels of PLCγ1 and its related signal molecules in BGC-823 cells were assessed using Western blot analysis or gelatine zymography assay. PLCγ1 was highly expressed in humangastric adenocarcinomas, especially in the region with lymph node metastasis. It was shown that migration of BGC-823 cells in vitro depends on PLCγ1 activation. This activation is mediated through Akt, an upstream of PLCγ1 that triggers the PLCγ1/extracellular signal-regulated kinase (ERK)/matrix metalloproteinase (MMP) pathway in BGC-823 cells. PLCγ1 activities play an important role in the metastasis of gastric adenocarcinoma, and may serve as a potential therapeutic target in this type of cancer
Changes of Circulating Transforming Growth Factor-²1 Level During Radiation Therapy Are Correlated with the Prognosis of Locally Advanced Non-small Cell Lung Cancer
IntroductionWe hypothesized that plasma transforming growth factor-²1 (TGF-²1) level and its dynamic change are correlated with the prognosis of locally advanced non-small cell lung cancer (NSCLC) treated with radiation therapy (RT).MethodsPatients with stage IIIA or IIIB NSCLC treated with RT with or without chemotherapy were eligible for this study. Platelet poor plasma was collected from each patient within 1 week before RT (pre-RT) and at the 4th week during RT (during-RT). TGF-²1 level was measured with enzyme-linked immunosorbent assay. The primary end point was overall survival (OS) and the secondary end point was progression-free survival (PFS). Kaplan-Meier and Cox regression were used for risk factor evaluation.ResultsA total of 65 patients were eligible for the study. The median OS and PFS were 17.7 and 13.7 months, respectively. In univariate analysis, performance status, weight loss, radiation dose, and TGF-²1 ratio (during-RT/pre-RT TGF-²1 level) were all significantly correlated with OS. In the multivariate analysis, performance status, radiation dose, and TGF-²1 ratio were still significantly correlated with OS. The median OS was 30.7 months for patients with TGF-²1 ratio ≤1 versus 13.3 months for those with TGF-²1 ratio more than 1 (p = 0.0029); and the median PFS was 16.8 months versus 7.2 months, respectively (p = 0.010).ConclusionsIn locally advanced NSCLC, the decrease of TGF-²1 level during RT is correlated with favorable prognosis
Epigenetically Mediated Pathogenic Effects of Phenanthrene on Regulatory T Cells
Phenanthrene (Phe), a polycyclic aromatic hydrocarbon (PAH), is a major constituent of urban air pollution. There have been conflicting results regarding the role of other AhR ligands 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD) and 6-formylindolo [3,2-b]carbazole (FICZ) in modifying regulatory T cell populations (Treg) or T helper (Th)17 differentiation, and the effects of Phe have been understudied. We hypothesized that different chemical entities of PAH induce Treg to become either Th2 or Th17 effector T cells through epigenetic modification of FOXP3. To determine specific effects on T cell populations by phenanthrene, primary human Treg were treated with Phe, TCDD, or FICZ and assessed for function, gene expression, and phenotype. Methylation of CpG sites within the FOXP3 locus reduced FOXP3 expression, leading to impaired Treg function and conversion of Treg into a CD4+CD25lo Th2 phenotype in Phe-treated cells. Conversely, TCDD treatment led to epigenetic modification of IL-17A and conversion of Treg to Th17 T cells. These findings present a mechanism by which exposure to AhR-ligands mediates human T cell responses and begins to elucidate the relationship between environmental exposures, immune modulation, and initiation of human disease
Genomic characterization of tigecycline-resistant Escherichia coli and Klebsiella pneumoniae isolates from hospital sewage
IntroductionThe tigecycline-resistant Enterobacterales have emerged as a great public concern, and the mobile tet(X) variants and tmexCD-toprJ efflux pump are mainly responsible for the spread of tigecycline resistance. Hospital sewage is considered as an important reservoir of antimicrobial resistance, while tigecycline resistance in this niche is under-researched.MethodsIn this study, five Escherichia coli and six Klebsiella pneumoniae strains were selected from a collection of tigecycline-resistant Enterobacterales for further investigation by antimicrobial susceptibility testing, conjugation, whole-genome sequencing, and bioinformatics analysis.ResultsAll five E. coli strains harbored tet(X4), which was located on different plasmids, including a novel IncC/IncFIA(HI1)/IncHI1A/IncHI1B(R27) hybrid structure. In addition, tet(X4)-bearing plasmids were able to transfer by conjugation and be stabilized in the recipient in the absence of antibiotics. tmexCD1-toprJ1 was identified in two K. pneumoniae (LZSFT39 and LZSRT3) and it was carried by a novel multidrug-resistance transposon, designated Tn7368, on a novel IncR/IncU hybrid plasmid. In addition, we found that two K. pneumoniae (LZSFZT3 and LZSRT3) showed overexpression of efflux genes acrB and oqxB, respectively, which was most likely to be caused by mutations in ramR and oqxR.DiscussionIn conclusion, the findings in this study expand our knowledge of the genetic elements that carry tigecycline resistance genes, which establishes a baseline for investigating the structure diversity and evolutionary trajectories of human, animal, and environmental tigecycline resistomes
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