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1.
Regul Toxicol Pharmacol ; : 105628, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38621523

RESUMO

New transfer coefficient (TC) values were derived for vineyard workers handling treated grapevines during harvesting and crop maintenance activities. Re-entry exposure and dislodgeable foliar residue (DFR) studies were performed in Europe, covering hand harvesting, pruning/training, pruning/tying and pruning /shoot lifting. Foliar applications of fungicides (iprovalicarb, dimethomorph, dithianon, pyrimethanil and fenbuconazole) were made and 73 workers at 16 sites were monitored over one working day. Exposure was measured on inner and outer dosimeters, face/neck wipes and hand washes. In concurrent DFR studies, leaf punches were taken at each site during the time of worker re-entry. Potential exposure values correlated well with DFR values. TC values were derived for various re-entry activities for potential and actual exposure, with and without gloves. The harvesting task resulted in lower TC values than the other crop maintenance tasks. Additional TC values reflecting the use of protective gloves can be derived from the results. The TC values are much lower than current European Food Safety Authority (EFSA) default values. This project addresses a data gap identified by EFSA for specific EU TC values to permit more realistic and reliable re-entry worker exposure estimates for grapes.

2.
Nuklearmedizin ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38593855

RESUMO

AIM: The aim of this study is to investigate whether computer-aided, semi-automated 3D lung lobe quantification can support decision-making on PE diagnosis based on the ventilation-perfusion ratio in clinical practice. METHODS: A study cohort of 100 patients (39 male, 61 female, age 64.8±15.8 years) underwent ventilation/perfusion single photon emission computed tomography (V/Q-SPECT/CT) to exclude acute PE on SPECT/CT OPTIMA NM/CT 640 (GE Healthcare). Two 3D lung lobe quantification software tools (Q. Lung: Xeleris 4.0, GE Healthcare and LLQ: Hermes Hybrid 3D Lung Lobar Quantification, Hermes Medical Solutions) were used to evaluate the numerical lobar ventilation/perfusion ratio (VQR) and lobar volume/perfusion ratio (VPR). A test of linearity and equivalence of the two 3D software tools was performed using Pearson, Spearman, quadratic weighted kappa and the mean squared deviation for VPR/VQR. An algorithm was developed that identified PE candidates using ROC analysis. The agreement between the PE findings of an experienced nuclear medicine expert and the calculated PE candidates was represented by the magnitude of the YOUDEN index (J) and the size of the area under the receiver operating curve (AUC). RESULTS: Both 3D software tools showed good comparability. The YOUDEN index for QLUNG(VPR/VQR)/LLQ(VPR/VQR) was in the range from 0.2 to 0.5. The mean AUC averaged over all lung lobes for QLUNG(VPR) was 0.66, CI95%: ±14.0%, for QLUNG(VQR) 0.66, CI95%: ±13.3%, for LLQ(VPR) 0.64, CI95%: ±14.7% and for LLQ(VQR) 0.65, CI95%: ±13.1%. CONCLUSION: This study reveals that 3D software tools are feasible for numerical PE detection. The clinical decision can be supported by using a numerical algorithm based on ROC analysis.

3.
Front Toxicol ; 6: 1370045, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38646442

RESUMO

The ICH S1B carcinogenicity global testing guideline has been recently revised with a novel addendum that describes a comprehensive integrated Weight of Evidence (WoE) approach to determine the need for a 2-year rat carcinogenicity study. In the present work, experts from different organizations have joined efforts to standardize as much as possible a procedural framework for the integration of evidence associated with the different ICH S1B(R1) WoE criteria. The framework uses a pragmatic consensus procedure for carcinogenicity hazard assessment to facilitate transparent, consistent, and documented decision-making and it discusses best-practices both for the organization of studies and presentation of data in a format suitable for regulatory review. First, it is acknowledged that the six WoE factors described in the addendum form an integrated network of evidence within a holistic assessment framework that is used synergistically to analyze and explain safety signals. Second, the proposed standardized procedure builds upon different considerations related to the primary sources of evidence, mechanistic analysis, alternative methodologies and novel investigative approaches, metabolites, and reliability of the data and other acquired information. Each of the six WoE factors is described highlighting how they can contribute evidence for the overall WoE assessment. A suggested reporting format to summarize the cross-integration of evidence from the different WoE factors is also presented. This work also notes that even if a 2-year rat study is ultimately required, creating a WoE assessment is valuable in understanding the specific factors and levels of human carcinogenic risk better than have been identified previously with the 2-year rat bioassay alone.

4.
Eur J Immunol ; : e2350873, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38501878

RESUMO

Resident memory T (TRM ) cells have been recently established as an important subset of memory T cells that provide early and essential protection against reinfection in the absence of circulating memory T cells. Recent findings showing that TRM expand in vivo after repeated antigenic stimulation indicate that these memory T cells are not terminally differentiated. This suggests an opportunity for in vitro TRM expansion to apply in an immunotherapy setting. However, it has also been shown that TRM may not maintain their identity and form circulating memory T cells after in vivo restimulation. Therefore, we set out to determine how TRM respond to antigenic activation in culture. Using Listeria monocytogenes and LCMV infection models, we found that TRM from the intraepithelial compartment of the small intestine expand in vitro after antigenic stimulation and subsequent resting in homeostatic cytokines. A large fraction of the expanded TRM retained their phenotype, including the expression of key TRM markers CD69 and CD103 (ITGAE). The optimal culture of TRM required low O2 pressure to maintain the expression of these and other TRM -associated molecules. Expanded TRM retained their effector capacity to produce cytokines after restimulation, but did not acquire a highly glycolytic profile indicative of effector T cells. The proteomic analysis confirmed TRM profile retention, including expression of TRM -related transcription factors, tissue retention factors, adhesion molecules, and enzymes involved in fatty acid metabolism. Collectively, our data indicate that limiting oxygen conditions supports in vitro expansion of TRM cells that maintain their TRM phenotype, at least in part, suggesting an opportunity for therapeutic strategies that require in vitro expansion of TRM .

5.
Biomolecules ; 14(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38540718

RESUMO

The amyloidogenic Aß peptides are widely considered as a pathogenic agent in Alzheimer's disease. Aß(1-42) would form aggregates of amyloid fibrils on the neuron plasma membranes, thus perturbing neuronal functionality. Conflicting data are available on the influence of bilayer order on Aß(1-42) binding to membranes. In the present study, a biophysical approach was used in which isothermal calorimetry and surface pressure measurements were applied to explore the interaction of Aß(1-42) in either monomeric, oligomeric, or fibrillar form with model membranes (bilayers or monolayers) in the liquid-ordered state that were either electrically neutral or negatively charged. In the latter case, this contained phosphatidic acid, cardiolipin, or ganglioside. The calorimetric studies showed that Aß(1-42) fibrils, oligomers, and monomers could bind and/or be inserted into bilayers, irrespective of electric charge, in the liquid-ordered state, except that monomers could not interact with electrically neutral bilayers. The monolayer studies in the Langmuir balance demonstrated that Aß(1-42) aggregation hindered peptide insertion into the monolayer, hindered insertion in the decreasing order of monomer > oligomer > fibril, and that lipid composition did not cause large differences in insertion, apart from a slight facilitation of monomer and oligomer insertion by gangliosides.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Humanos , Peptídeos beta-Amiloides/metabolismo , Amiloide/química , Fragmentos de Peptídeos/metabolismo , Doença de Alzheimer/metabolismo , Gangliosídeos
6.
ACS Synth Biol ; 13(4): 1343-1354, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38459634

RESUMO

Production of phytocannabinoids remains an area of active scientific interest due to the growing use of cannabis by the public and the underexplored therapeutic potential of the over 100 minor cannabinoids. While phytocannabinoids are biosynthesized by Cannabis sativa and other select plants and fungi, structural analogs and stereoisomers can only be accessed synthetically or through heterologous expression. To date, the bioproduction of cannabinoids has required eukaryotic hosts like yeast since key, native oxidative cyclization enzymes do not express well in bacterial hosts. Here, we report that two marine bacterial flavoenzymes, Clz9 and Tcz9, perform oxidative cyclization reactions on phytocannabinoid precursors to efficiently generate cannabichromene scaffolds. Furthermore, Clz9 and Tcz9 express robustly in bacteria and display significant tolerance to organic solvent and high substrate loading, thereby enabling fermentative production of cannabichromenic acid in Escherichia coli and indicating their potential for biocatalyst development.


Assuntos
Canabinoides , Cannabis , Canabinoides/química , Cannabis/química , Cannabis/metabolismo , Bactérias
7.
PLoS One ; 19(2): e0297175, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38335163

RESUMO

The host immune system plays a significant role in managing and clearing pathogen material during an infection, but this complex process presents numerous challenges from a modeling perspective. There are many mathematical and statistical models for these kinds of processes that take into account a wide range of events that happen within the host. In this work, we present a Bayesian joint model of longitudinal and time-to-event data of Leishmania infection that considers the interplay between key drivers of the disease process: pathogen load, antibody level, and disease. The longitudinal model also considers approximate inflammatory and regulatory immune factors. In addition to measuring antibody levels produced by the immune system, we adapt data from CD4+ and CD8+ T cell proliferation, and expression of interleukin 10, interferon-gamma, and programmed cell death 1 as inflammatory or regulatory factors mediating the disease process. The model is developed using data collected from a cohort of dogs naturally exposed to Leishmania infantum. The cohort was chosen to start with healthy infected animals, and this is the majority of the data. The model also characterizes the relationship features of the longitudinal outcomes and time-to-death due to progressive Leishmania infection. In addition to describing the mechanisms causing disease progression and impacting the risk of death, we also present the model's ability to predict individual trajectories of Canine Leishmaniosis (CanL) progression. The within-host model structure we present here provides a way forward to address vital research questions regarding the understanding of the progression of complex chronic diseases such as Visceral Leishmaniasis, a parasitic disease causing significant morbidity worldwide.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Humanos , Animais , Cães , Teorema de Bayes , Leishmaniose/veterinária , Leishmaniose Visceral/parasitologia , Interferon gama , Linfócitos T CD8-Positivos
8.
Eur J Nucl Med Mol Imaging ; 51(5): 1268-1286, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38366197

RESUMO

The numbers of diagnostic and therapeutic nuclear medicine agents under investigation are rapidly increasing. Both novel emitters and novel carrier molecules require careful selection of measurement procedures. This document provides guidance relevant to dosimetry for first-in human and early phase clinical trials of such novel agents. The guideline includes a short introduction to different emitters and carrier molecules, followed by recommendations on the methods for activity measurement, pharmacokinetic analyses, as well as absorbed dose calculations and uncertainty analyses. The optimal use of preclinical information and studies involving diagnostic analogues is discussed. Good practice reporting is emphasised, and relevant dosimetry parameters and method descriptions to be included are listed. Three examples of first-in-human dosimetry studies, both for diagnostic tracers and radionuclide therapies, are given.


Assuntos
Medicina Nuclear , Compostos Radiofarmacêuticos , Humanos , Compostos Radiofarmacêuticos/uso terapêutico , Radiometria/métodos , Cintilografia , Medicina Nuclear/métodos
9.
Eur J Immunol ; 54(4): e2149641, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38314819

RESUMO

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasingly common complication of obesity, affecting over a quarter of the global adult population. A key event in the pathophysiology of MASLD is the development of metabolic-associated steatohepatitis (MASH), which greatly increases the chances of developing cirrhosis and hepatocellular carcinoma. The underlying cause of MASH is multifactorial, but accumulating evidence indicates that the inflammatory process in the hepatic microenvironment typically follows a pattern that can be roughly divided into three stages: (1) Detection of hepatocyte stress by tissue-resident immune cells including γδ T cells and CD4-CD8- double-negative T cells, followed by their secretion of pro-inflammatory mediators, most notably IL-17A. (2) Recruitment of pro-inflammatory cells, mostly of the myeloid lineage, and initiation of inflammation through secretion of effector-type cytokines such as TNF, TGF-ß, and IL-1ß. (3) Escalation of the inflammatory response by recruitment of lymphocytes including Th17, CD8 T, and B cells leading to chronic inflammation, hepatic stellate cell activation, and fibrosis. Here we will discuss these three stages and how they are consecutively linked like falling domino tiles to the pathophysiology of MASH. Moreover, we will highlight the clinical potential of inflammation as a biomarker and therapeutic target for the treatment of MASLD.


Assuntos
Fígado Gorduroso , Neoplasias Hepáticas , Doenças Metabólicas , Adulto , Humanos , Linfócitos B , Inflamação , Microambiente Tumoral
10.
Int J Biol Macromol ; 262(Pt 1): 129835, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38302024

RESUMO

Autophagy is a catabolic process in which a double-membrane organelle, the autophagosome (AP), engulfs cellular components that will be degraded in the lysosomes. ATG8 protein family members participate at various stages of AP formation. The present study compares the capacity to induce lipid-vesicle tethering and fusion of two ATG8 family members, LC3B and LC3C, with model membranes. LC3B is the most thoroughly studied ATG8 protein. It is generally considered as an autophagosomal marker and a canonical representative of the LC3 subfamily. LC3C is less studied, but recent data have reported its implication in various processes, crucial to cellular homeostasis. The results in this paper show that LC3C induces higher levels of tethering and of intervesicular lipid mixing than LC3B. As the N-terminus of LC3C is different from that of the other family members, various mutants of the N-terminal region of both LC3B and LC3C were designed, and their activities compared. It was concluded that the N-terminal region of LC3C was responsible for the enhanced vesicle tethering, membrane perturbation and vesicle-vesicle fusion activities of LC3C as compared to LC3B. The results suggest a specialized function of LC3C in the AP expansion process.


Assuntos
Fusão de Membrana , Proteínas Associadas aos Microtúbulos , Família da Proteína 8 Relacionada à Autofagia/genética , Família da Proteína 8 Relacionada à Autofagia/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Autofagia , Lipídeos
11.
Regul Toxicol Pharmacol ; 148: 105584, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38417477

RESUMO

The increasing drive to understand the likelihood of skin sensitisation from plant protection products (PPPs) in workers and the general public has resulted in recent initiatives to establish a quantitative risk assessment (QRA) methodology applicable to these products and their exposure scenarios. The effective evaluation of skin sensitising substances requires not only the identification of that toxicological hazard, but also determination of relative sensitising potency. Typically, this has been achieved by interpretation of local lymph node assay (LLNA) dose response data, delivering what is known as the EC3 value. This permitted regulatory division of skin sensitisers into defined potency sub-categories, but more importantly enabled derivation of a no expected sensitisation induction level (NESIL) as the point of departure for QRA. However, for many existing substances there is no LLNA data, only older guinea pig results exist. To avoid additional (in vivo) testing, an approach has been outlined to employ guinea pig data and existing regulatory guidelines on the determination of potency sub-categorisation to provide a guinea pig based NESIL. The approach adopts a conservative extrapolation from LLNA NESIL benchmarks to deliver points of departure as the basis for the type of QRA process already in successful use by other industries.


Assuntos
Dermatite Alérgica de Contato , Cobaias , Animais , Dermatite Alérgica de Contato/prevenção & controle , Alérgenos/toxicidade , Pele , Ensaio Local de Linfonodo , Medição de Risco/métodos
12.
Cell Mol Life Sci ; 81(1): 98, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38386110

RESUMO

In hormone-responsive breast cancer cells, progesterone (P4) has been shown to act via its nuclear receptor (nPR), a ligand-activated transcription factor. A small fraction of progesterone receptor is palmitoylated and anchored to the cell membrane (mbPR) forming a complex with estrogen receptor alpha (ERα). Upon hormone exposure, either directly or via interaction with ERα, mbPR activates the SRC/RAS/ERK kinase pathway leading to phosphorylation of nPR by ERK. Kinase activation is essential for P4 gene regulation, as the ERK and MSK1 kinases are recruited by the nPR to its genomic binding sites and trigger chromatin remodeling. An interesting open question is whether activation of mbPR can result in gene regulation in the absence of ligand binding to intracellular progesterone receptor (iPR). This matter has been investigated in the past using P4 attached to serum albumin, but the attachment is leaky and albumin can be endocytosed and degraded, liberating P4. Here, we propose a more stringent approach to address this issue by ensuring attachment of P4 to the cell membrane via covalent binding to a stable phospholipid. This strategy identifies the actions of P4 independent from hormone binding to iPR. We found that a membrane-attached progestin can activate mbPR, the ERK signaling pathway leading to iPR phosphorylation, initial gene regulation and entry into the cell cycle, in the absence of detectable intracellular progestin.


Assuntos
Neoplasias , Progesterona , Progesterona/farmacologia , Receptores de Progesterona/genética , Receptor alfa de Estrogênio , Progestinas/farmacologia , Ligantes , Membrana Celular
13.
Breast Cancer Res ; 26(1): 30, 2024 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378689

RESUMO

INTRODUCTION: Overexpression of prostate-specific membrane antigen (PSMA) on the vasculature of triple-negative breast cancer (TNBC) presents a promising avenue for targeted endogenous radiotherapy with [177Lu]Lu-PSMA-I&T. This study aimed to assess and compare the therapeutic efficacy of a single dose with a fractionated dose of [177Lu]Lu-PSMA-I&T in an orthotopic model of TNBC. METHODS: Rj:NMRI-Foxn1nu/nu mice were used as recipients of MDA-MB-231 xenografts. The single dose group was treated with 1 × 60 ± 5 MBq dose of [177Lu]Lu-PSMA-I&T, while the fractionated dose group received 4 × a 15 ± 2 MBq dose of [177Lu]Lu-PSMA-I&T at 7 day intervals. The control group received 0.9% NaCl. Tumor progression was monitored using [18F]FDG-PET/CT. Ex vivo analysis encompassed immunostaining, TUNEL staining, H&E staining, microautoradiography, and autoradiography. RESULTS: Tumor volumes were significantly smaller in the single dose (p < 0.001) and fractionated dose (p < 0.001) groups. Tumor growth inhibition rates were 38% (single dose) and 30% (fractionated dose). Median survival was notably prolonged in the treated groups compared to the control groups (31d, 28d and 19d for single dose, fractionated dose and control, respectively). [177Lu]Lu-PSMA-I&T decreased the size of viable tumor areas. We further demonstrated, that [177Lu]Lu-PSMA-I&T binds specifically to the tumor-associated vasculature. CONCLUSION: This study highlights the potential of [177Lu]Lu-PSMA-I&T for endogenous radiotherapy of TNBC.


Assuntos
Radioisótopos , Neoplasias de Mama Triplo Negativas , Humanos , Masculino , Animais , Camundongos , Radioisótopos/uso terapêutico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Compostos Radiofarmacêuticos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Próstata/metabolismo , Linhagem Celular Tumoral , Dipeptídeos/uso terapêutico
15.
Angew Chem Int Ed Engl ; : e202319235, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38407532

RESUMO

The world in which we live is homochiral. The ribose units that form the backbone of DNA and RNA are all D-configured and the encoded amino acids that comprise the proteins of all living species feature an all-L-configuration at the α-carbon atoms. The homochirality of α-amino acids is essential for folding of the peptides into well-defined and functional 3D structures and the homochirality of D-ribose is crucial for helix formation and base-pairing. The question of why nature uses only encoded L-α-amino acids is not understood. Herein, we show that an RNA-peptide world, in which peptides grow on RNAs constructed from D-ribose, leads to the self-selection of homo-L-peptides, which provides a possible explanation for the homo-D-ribose and homo-L-amino acid combination seen in nature.

16.
Skeletal Radiol ; 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38277027

RESUMO

PURPOSE: To report normative stiffness parameters obtained using shear wave elastography in dorsiflexion from the Achilles tendons in asymptomatic professional ballet dancers and compare them with college-level athletes. METHODS: An Institutional Review Board (IRB)-approved study consists of 28 professional ballet dancers and 64 asymptomatic collegiate athletes. The athletes were further subdivided into runner and non-runner disciplines. Shear wave elastography (SWE) measurements were made in maximum ankle dorsiflexion position. RESULTS AND DISCUSSION: Forty-eight (52%) males and 44 (48%) females were examined with an overall mean age of 22.2 (± 3.8 years). There were no significant SWE differences between dominant and non-dominant legs in both groups and comparing spin vs. non-spin leg of ballet dancers (p > 0.05). Ballet dancers had significantly higher short-axis velocity values than runners and non-runners (2.34 m/s increase and 2.79 m/s increase, respectively, p < 0.001). Long-axis velocity was significantly higher in ballet dancers compared to non-runners (by 0.80 m/s, p < 0.001), but was not different between ballet dancers and runners (p > 0.05). Short-axis modulus was significantly higher in dancers compared to runners and non-runners (by 135.2 kPa and 159.2 kPa, respectively, p < 0.001). Long-axis modulus (LAM) was not significantly different in ballet dancers when compared to runners. CONCLUSION: Asymptomatic professional ballet dancers exhibit greater short-axis tendon stiffness compared to athletes and greater long-axis tendon stiffness compared to non-runners but similar to runners. The functional benefit from elevated short-axis stiffness in dancers is not clear but may be related to greater axial loading and adaptations of the tendon matrix.

17.
HNO ; 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38214716

RESUMO

BACKGROUND: Treatment of Epstein-Barr virus(EBV)-positive nasopharyngeal carcinoma (NPC) with cisplatin/5-fluorouracil (5-FU) induction chemotherapy, followed by radiochemotherapy and subsequent interferon­ß, has yielded high survival rates in children, adolescents, and young adults. A previous study has shown that reduction of radiation dose from 59.4 to 54.0 Gy appears to be safe in patients with complete response (CR) to induction chemotherapy. As immune checkpoint-inhibitors have shown activity in NPC, we hypothesize that the addition of nivolumab to standard induction chemotherapy would increase the rate of complete tumor responses, thus allowing for a reduced radiation dose in a greater proportion of patients. METHODS: This is a prospective multicenter phase 2 clinical trial including pediatric and adult patients with their first diagnosis of EBV-positive NPC, scheduled to receive nivolumab in addition to standard induction chemotherapy. In cases of non-response to induction therapy (stable or progressive disease), and in patients with initial distant metastasis, treatment with nivolumab will be continued during radiochemotherapy. Primary endpoint is tumor response on magnetic resonance imaging (MRI) and positron emission tomography (PET) after three cycles of induction chemotherapy. Secondary endpoints are event-free (EFS) and overall survival (OS), safety, and correlation of tumor response with programmed cell death ligand 1 (PD-L1) expression. DISCUSSION: As cure rates in localized EBV-positive NPC today are high with standard multimodal treatment, the focus increasingly shifts toward prevention of late effects, the burden of which is exceptionally high, mainly due to intense radiotherapy. Furthermore, survival in patients with metastatic disease and resistant to conventional chemotherapy remains poor. Primary objective of this study is to investigate whether the addition of nivolumab to standard induction chemotherapy in children and adults with EBV-positive NPC is able to increase the rate of complete responses, thus enabling a reduction in radiation dose in more patients, but also offer patients with high risk of treatment failure the chance to benefit from the addition of nivolumab. TRIAL REGISTRATION: EudraCT (European Union Drug Regulating Authorities Clinical Trials Database) No. 2021-006477-32.

18.
Bioinformatics ; 40(1)2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38195862

RESUMO

MOTIVATION: Boolean networks can serve as straightforward models for understanding processes such as gene regulation, and employing logical rules. These rules can either be derived from existing literature or by data-driven approaches. However, in the context of large networks, the exhaustive search for intervention targets becomes challenging due to the exponential expansion of a Boolean network's state space and the multitude of potential target candidates, along with their various combinations. Instead, we can employ the logical rules and resultant interaction graph as a means to identify targets of specific interest within larger-scale models. This approach not only facilitates the screening process but also serves as a preliminary filtering step, enabling the focused investigation of candidates that hold promise for more profound dynamic analysis. However, applying this method requires a working knowledge of R, thus restricting the range of potential users. We, therefore, aim to provide an application that makes this method accessible to a broader scientific community. RESULTS: Here, we introduce GatekeepR, a graphical, web-based R Shiny application that enables scientists to screen Boolean network models for possible intervention targets whose perturbation is likely to have a large impact on the system's dynamics. This application does not require a local installation or knowledge of R and provides the suggested targets along with additional network information and visualizations in an intuitive, easy-to-use manner. The Supplementary Material describes the underlying method for identifying these nodes along with an example application in a network modeling pancreatic cancer. AVAILABILITY AND IMPLEMENTATION: https://www.github.com/sysbio-bioinf/GatekeepR https://abel.informatik.uni-ulm.de/shiny/GatekeepR/.


Assuntos
Redes Reguladoras de Genes , Software , Regulação da Expressão Gênica
19.
Neurooncol Adv ; 6(1): vdad151, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38196739

RESUMO

Background: In glioma patients, tumor growth and subsequent treatments are associated with various types of brain lesions. We hypothesized that cognitive functioning in these patients critically depends on the maintained structural connectivity of multiple brain networks. Methods: The study included 121 glioma patients (median age, 52 years; median Eastern Cooperative Oncology Group performance score 1; CNS-WHO Grade 3 or 4) after multimodal therapy. Cognitive performance was assessed by 10 tests in 5 cognitive domains at a median of 14 months after treatment initiation. Hybrid amino acid PET/MRI using the tracer O-(2-[18F]fluoroethyl)-L-tyrosine, a network-based cortical parcellation, and advanced tractography were used to generate whole-brain fiber count-weighted connectivity matrices. The matrices were applied to a cross-validated machine-learning model to identify predictive fiber connections (edges), critical cortical regions (nodes), and the networks underlying cognitive performance. Results: Compared to healthy controls (n = 121), patients' cognitive scores were significantly lower in 9 cognitive tests. The models predicted the scores of 7/10 tests (median correlation coefficient, 0.47; range, 0.39-0.57) from 0.6% to 5.4% of the matrix entries; 84% of the predictive edges were between nodes of different networks. Critically involved cortical regions (≥10 adjacent edges) included predominantly left-sided nodes of the visual, somatomotor, dorsal/ventral attention, and default mode networks. Highly critical nodes (≥15 edges) included the default mode network's left temporal and bilateral posterior cingulate cortex. Conclusions: These results suggest that the cognitive performance of pretreated glioma patients is strongly related to structural connectivity between multiple brain networks and depends on the integrity of known network hubs also involved in other neurological disorders.

20.
Psychiatr Prax ; 51(1): 49-52, 2024 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-37673094

RESUMO

A risk of suicide in the course of a psychiatric disorder will often be answered with an admission for inpatient psychiatric treatment, resulting in a high potential of suicidal behavior on the ward. Despite extensive safety precautions and therapeutic interventions, suicides still occur within psychiatric hospitals. Such incidents, known as inpatient suicides, are rare but significant, necessitating further examination. We present the case of a 91-year-old suicidal male patient, who committed suicide on an open ward on a Sunday morning by blocking his nostrils with cotton and tissue and breathing into a pillow, leading to death by asphyxia. The case report aims to draw attention to the possibility of this extraordinary method of suicide, demonstrating that a suicide can be accomplished in a psychiatric hospital even without the use of prohibited dangerous objects.


Assuntos
Transtornos Mentais , Suicídio , Humanos , Masculino , Idoso de 80 Anos ou mais , Suicídio/psicologia , Asfixia/diagnóstico , Asfixia/terapia , Pacientes Internados/psicologia , Alemanha , Transtornos Mentais/psicologia
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