RESUMEN
In recent years, we have witnessed both artificial intelligence obtaining remarkable results in clinical decision support systems (CDSSs) and explainable artificial intelligence (XAI) improving the interpretability of these models. In turn, this fosters the adoption by medical personnel and improves trustworthiness of CDSSs. Among others, counterfactual explanations prove to be one such XAI technique particularly suitable for the healthcare domain due to its ease of interpretation, even for less technically proficient staff. However, the generation of high-quality counterfactuals relies on generative models for guidance. Unfortunately, training such models requires a huge amount of data that is beyond the means of ordinary hospitals. In this paper, we therefore propose to use federated learning to allow multiple hospitals to jointly train such generative models while maintaining full data privacy. We demonstrate the superiority of our approach compared to locally generated counterfactuals. Moreover, we prove that generative models for counterfactual generation that are trained using federated learning in a suitable environment perform only marginally worse compared to centrally trained ones while offering the benefit of data privacy preservation. Finally, we integrate our method into a prototypical CDSS for treatment recommendation for sepsis patients, thus providing a proof of concept for real-world application as well as insights and sanity checks from clinical application.
RESUMEN
Targeted infection diagnosis supports decision-making in the rational use of antibiotics usually encompassed as Antibiotic Stewardship (ABS). Similar to ABS, the term "Diagnostic Stewardship" (DGS) is suggested, whereas DGS includes, beneath general, predominantly microbiological infection diagnostics - with specific pathogen detection, conventional via culture or immunology, increasingly also using molecular biological methods. Especially in microbiology, pre-analytics, analytics and post-analytics play an essential role. Pathogen characterization is accompanied by an antimicrobial susceptibility test (with S-I-R classification), which deserves special attention, especially in the context of ABS.âAll of these aspects are dealt with in this work and represented using two practical examples of urinary and bloodstream diagnostics that are relevant for outpatients and inpatients.
Asunto(s)
Programas de Optimización del Uso de los Antimicrobianos , Medicina Hospitalar , Humanos , Pacientes Ambulatorios , Cultivo de Sangre , Enfermedades Transmisibles/diagnóstico , Infecciones Urinarias/diagnósticoRESUMEN
Genomic surveillance of the SARS-CoV-2 pandemic is crucial and mainly achieved by amplicon sequencing protocols. Overlapping tiled-amplicons are generated to establish contiguous SARS-CoV-2 genome sequences, which enable the precise resolution of infection chains and outbreaks. We investigated a SARS-CoV-2 outbreak in a local hospital and used nanopore sequencing with a modified ARTIC protocol employing 1200 bp long amplicons. We detected a long deletion of 168 nucleotides in the ORF8 gene in 76 samples from the hospital outbreak. This deletion is difficult to identify with the classical amplicon sequencing procedures since it removes two amplicon primer-binding sites. We analyzed public SARS-CoV-2 sequences and sequencing read data from ENA and identified the same deletion in over 100 genomes belonging to different lineages of SARS-CoV-2, pointing to a mutation hotspot or to positive selection. In almost all cases, the deletion was not represented in the virus genome sequence after consensus building. Additionally, further database searches point to other deletions in the ORF8 coding region that have never been reported by the standard data analysis pipelines. These findings and the fact that ORF8 is especially prone to deletions, make a clear case for the urgent necessity of public availability of the raw data for this and other large deletions that might change the physiology of the virus towards endemism.
Asunto(s)
COVID-19/virología , Genes Virales , SARS-CoV-2/genética , Eliminación de Secuencia , Variación Genética , Humanos , Secuenciación de Nanoporos , Sistemas de Lectura Abierta , Análisis de Secuencia de ARN , Secuenciación Completa del GenomaRESUMEN
Many tumor cells exhibit a disturbed intracellular redox state resulting in higher levels of reactive oxygen species (ROS). As these contribute to tumor initiation and sustenance, catalytic redox agents combining significant activity with substrate specificity promise high activity and selectivity against oxidatively stressed malignant cells. We describe here the design and synthesis of novel organochalcogen based redox sensor/effector catalysts. Their selective anticancer activity at submicromolar and low micromolar concentrations was established here in a range of tumor entities in various biological systems including cell lines, primary tumor cell cultures, and animal models. In the B-cell derived chronic lymphocytic leukemia (CLL), for instance, such compounds preferentially induce apoptosis in the cancer cells while peripheral blood mononuclear cells (PBMC) from healthy donors and the subset of normal B-cells remain largely unaffected. In support of the concept of sensor/effector based ROS amplification, we are able to demonstrate that underlying this selective activity against CLL cells are pre-existing elevated ROS levels in the leukemic cells compared to their nonmalignant counterparts. Furthermore, the catalysts act in concert with certain chemotherapeutic drugs in several carcinoma cell lines to decrease cell proliferation while showing no such interactions in normal cells. Overall, the high efficacy and selectivity of (redox) catalytic sensor/effector compounds warrant further, extensive testing toward transfer into the clinical arena.
Asunto(s)
Antineoplásicos/síntesis química , Compuestos de Organoselenio/síntesis química , Quinonas/síntesis química , Sulfuros/síntesis química , Telurio , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Catálisis , Línea Celular , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/patología , Leucocitos Mononucleares/efectos de los fármacos , Ratones , Naftoquinonas/síntesis química , Naftoquinonas/química , Naftoquinonas/farmacología , Compuestos de Organoselenio/química , Compuestos de Organoselenio/farmacología , Oxidación-Reducción , Quinonas/química , Quinonas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Relación Estructura-Actividad , Sulfuros/química , Sulfuros/farmacologíaRESUMEN
Naturally occurring organic sulfur compounds (OSCs), such as linear allylsulfides from Allium species, are attracting attention in cancer research, since several OSCs were shown to act beneficially both in chemoprevention and in chemotherapy, while hardly exerting any harmful side effects. Hence, we investigated the possible role of different OSCs in the treatment of leukemia. Thereby, we found that the compounds tested in this study induced apoptosis in U937 cells, with an efficiency depending on the number of sulfides, and selected the most promising candidate, diallyltetrasulfide (Al2S4), for detailed mechanistic studies. Here we show that Al2S4 induced an accumulation of cells in early mitosis (G2/M phase), followed by the activation of caspase-dependent apoptosis. The compound counteracted different anti-apoptotic Bcl-2 family members (Bcl-xL, phospho-Bad and Bcl-2), promoted activation of Bax and Bak and induced the release of cytochrome c into the cytoplasm. Treatment by Al2S4 let to the identification of early apoptotic events including Bcl-xL degradation, Bak activation and release of cytochrome c followed by late events including Bcl-2 proteolysis, Bax activation, Bad dephosphorylation, caspase activation, nuclear fragmentation and phosphatidylserine exposure.
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Apoptosis/efectos de los fármacos , Caspasas/metabolismo , Mitosis/efectos de los fármacos , Sulfuros/farmacología , Donantes de Sangre , Supervivencia Celular/efectos de los fármacos , Citocromos c/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Activación Enzimática/efectos de los fármacos , Citometría de Flujo , Salud , Humanos , Leucemia/patología , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Sulfuros/química , Factores de Tiempo , Células U937 , Proteína Destructora del Antagonista Homólogo bcl-2/metabolismo , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Human 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) catalyzes the reduction of the weak estrogen estrone (E1) to the highly potent estradiol (E2). This reaction takes place in the target cell where the estrogenic effect is exerted via the estrogen receptor (ER). Estrogens, especially E2, are known to stimulate the proliferation of hormone-dependent diseases. 17beta-HSD1 is overexpressed in many breast tumors. Thus, it is an attractive target for the treatment of these diseases. Ligand- and structure-based drug design led to the discovery of novel, selective, and potent inhibitors of 17beta-HSD1. Phenyl-substituted bicyclic moieties were synthesized as mimics of the steroidal substrate. Computational methods were used to obtain insight into their interactions with the protein. Compound 5 turned out to be a highly potent inhibitor of 17beta-HSD1 showing good selectivity (17beta-HSD2, ERalpha and beta), medium cell permeation, reasonable metabolic stability (rat hepatic microsomes), and little inhibition of hepatic CYP enzymes.
Asunto(s)
17-Hidroxiesteroide Deshidrogenasas/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Estrógenos/metabolismo , Naftalenos/síntesis química , Naftalenos/farmacología , Neoplasias Hormono-Dependientes/tratamiento farmacológico , Neoplasias Hormono-Dependientes/enzimología , Quinolinas/síntesis química , Quinolinas/farmacología , Animales , Hidrocarburo de Aril Hidroxilasas/antagonistas & inhibidores , Sitios de Unión , Células CACO-2 , Simulación por Computador , Diseño de Fármacos , Inhibidores Enzimáticos/química , Humanos , Enlace de Hidrógeno , Hígado/enzimología , Masculino , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Estructura Molecular , Naftalenos/química , Quinolinas/química , Ratas , Ratas Sprague-Dawley , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
In this study, the synthesis and biological evaluation of heteroaryl-substituted dihydronaphthalenes and indenes (1-16) is described. The compounds were tested for activity by use of human CYP11B2 expressed in fission yeast and V79 MZh cells and for selectivity by use of human CYP11B1, CYP17, and CYP19. The most active inhibitor was the 6-methoxydihydronaphthalene 4 (IC(50) = 2 nM), showing a K(i) value of 1.3 nM and a competitive type of inhibition. The 5-methoxyindene 3 was found to be the most selective CYP11B2 inhibitor (IC(50) = 4 nM; CYP11B1 IC(50) = 5684 nM), which also showed only marginal inhibition of human CYP3A4 and CYP2D6. Docking and molecular dynamics studies using our homology-modeled CYP11B2 structure were performed to understand some structure-activity relationships. Caco-2 cell experiments revealed highly cell-permeable compounds, and metabolic studies with 4 using rat liver microsomes showed sufficient stability.
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Citocromo P-450 CYP11B2/antagonistas & inhibidores , Insuficiencia Cardíaca/tratamiento farmacológico , Indenos/síntesis química , Miocardio/patología , Naftalenos/síntesis química , Animales , Sitios de Unión , Línea Celular , Permeabilidad de la Membrana Celular , Cricetinae , Cricetulus , Fibrosis , Humanos , Indenos/química , Indenos/farmacología , Modelos Moleculares , Naftalenos/química , Naftalenos/farmacología , Schizosaccharomyces , Relación Estructura-ActividadRESUMEN
Novel substituted benzoyl benzoic acids and phenylacetic acids 1-14 have been synthesized and evaluated for inhibition of rat and human steroid 5alpha-reductase isozymes 1 and 2. The compounds turned out to be potent and selective human type 2 enzyme inhibitors, exhibiting IC(50) values in the nanomolar range. The phenylacetic acid derivatives were more potent than the analogous benzoic acids. Bromination in the 4-position of the phenoxy moiety led to the strongest inhibitor in this class (12; IC(50) = 5 nM), which was equipotent to finasteride. Since oral absorption is essential for a potential drug, 12 was further examined. In the parallel artificial membrane permeation assay (PAMPA) it turned out to be a good permeator, whereas it was a medium permeator in Caco2 cells. After oral administration (40 mg/kg) to rats a high bioavailability and a biological half-life of 5.5 h were observed, making it a promising candidate for clinical evaluation.
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Inhibidores de 5-alfa-Reductasa , Benzoatos/síntesis química , Fenilacetatos/síntesis química , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa , Administración Oral , Animales , Benzoatos/química , Benzoatos/farmacocinética , Línea Celular , Permeabilidad de la Membrana Celular , Humanos , Isoenzimas/antagonistas & inhibidores , Masculino , Membranas Artificiales , Modelos Moleculares , Permeabilidad , Fenilacetatos/química , Fenilacetatos/farmacocinética , Próstata/enzimología , Hiperplasia Prostática/enzimología , Neoplasias de la Próstata/enzimología , Ratas , Ratas Wistar , Relación Estructura-ActividadRESUMEN
Recently we proposed inhibition of aldosterone synthase (CYP11B2) as a novel strategy for the treatment of congestive heart failure and myocardial fibrosis. In this study the synthesis and biological evaluation of heteroaryl-substituted naphthalenes and quinolines (1-31) is described. Key step for the preparation of the compounds was a Suzuki cross-coupling. Activity of the compounds was determined in vitro using human CYP11B2 and selectivity was evaluated toward the human steroidogenic enzymes CYP11B1, CYP19, and CYP17. A large number of highly active and selective inhibitors of CYP11B2 was identified. The most active inhibitor was the 6-cyano compound 8 (IC50 = 3 nM) showing a competitive type of inhibition (K(i) value = 1.9 nM). The 6-ethoxy derivative 5 was found to be the most selective CYP11B2 inhibitor (IC50 = 12 nM; K(i) value = 8 nM; CYP11B1 IC50 = 5419 nM; selectivity factor = 451), showing no inhibition of human CYP3A4 (50 nM) and CYP2D6 (20 nM). Docking and molecular dynamics studies using our homology modeled CYP11B2 structure with selected compounds were performed. Caco-2 cell experiments revealed a large number of medium and highly permeable compounds and metabolic studies with 2 using rat liver microsomes showed sufficient stability.
Asunto(s)
Citocromo P-450 CYP11B2/antagonistas & inhibidores , Insuficiencia Cardíaca/tratamiento farmacológico , Miocardio/patología , Naftalenos/síntesis química , Aromatasa/química , Aromatasa/metabolismo , Inhibidores de la Aromatasa/síntesis química , Inhibidores de la Aromatasa/química , Inhibidores de la Aromatasa/farmacología , Células CACO-2 , Permeabilidad de la Membrana Celular , Citocromo P-450 CYP11B2/química , Fibrosis/tratamiento farmacológico , Humanos , Técnicas In Vitro , Hígado/enzimología , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Naftalenos/química , Naftalenos/farmacología , Schizosaccharomyces/efectos de los fármacos , Schizosaccharomyces/enzimología , Esteroide 11-beta-Hidroxilasa/antagonistas & inhibidores , Esteroide 11-beta-Hidroxilasa/química , Esteroide 17-alfa-Hidroxilasa/antagonistas & inhibidores , Esteroide 17-alfa-Hidroxilasa/química , Relación Estructura-ActividadRESUMEN
Steroid 5alpha-reductase (5alphaR) inhibitory potency of three N-(dicyclohexyl)acetyl-piperidine-4-(benzylidene-4-carboxylic acids) and their corresponding methyl esters was monitored for type 2 isoenzyme in a benign prostatic hyperplasia cell free preparation and for type 1 isoenzyme in DU145 cells and in a cell free assay. The hydrolytic stability of the esters and their bioconversion to the corresponding acids was assessed in aqueous buffered solution (pH 7.4) and in selected biological media having measurable esterase activities. The carboxylic acids 1, 2, and 3 with high type 2 inhibitory potencies displayed only little type 1 inhibition. The esters 1a, 2a, and 3a, originally designed as prodrugs to enhance cell permeation, proved to be potent type 1 inhibitors and are therefore acting as drugs themselves. They are stable in buffered salt solution (pH 7.4), Caco-2 cells, and human plasma, whereas all esters are cleaved into the corresponding acids in benign prostatic hyperplasia tissue homogenate. Methyl esters, applied as hydrolytically stable precursor drugs to facilitate cell permeation, will yield the corresponding carboxylic acids as type 2 inhibitors after hydrolysis in the target organ. The esters themselves--stable in human plasma and Caco-2 cells--are acting as potent drugs toward 5alphaR type 1. Thus, dual inhibition of 5alphaR type 1 and type 2 can be achieved by applying a single parent compound.
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Inhibidores de 5-alfa-Reductasa , Compuestos de Bencilideno/farmacología , Ácidos Carboxílicos/farmacología , Inhibidores Enzimáticos/farmacología , Piperidinas/farmacología , Profármacos/farmacología , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/clasificación , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , Compuestos de Bencilideno/química , Células CACO-2 , Ácidos Carboxílicos/química , Línea Celular Tumoral , Inhibidores Enzimáticos/química , Ésteres , Humanos , Isoenzimas/antagonistas & inhibidores , Isoenzimas/clasificación , Isoenzimas/metabolismo , Piperidinas/química , Profármacos/químicaRESUMEN
Cellular fatty acids of Helicobacter pylori have taxonomic, physiological, and pathogenic implications. However, little is known about the fatty acid composition under various culture conditions. H. pylori is usually grown on blood-supplemented complex media, and the fatty acids in the blood may affect the fatty acids in the cells. In addition, frequently subcultivated laboratory-adapted strains may have properties different from those of fresh clinical isolates, which are culturable only for a limited number of passages. Therefore, the cellular fatty acid profiles of laboratory-adapted strains (LAS) and freshly isolated strains (FIS) were compared after growth on agar that was fatty acid free and growth on blood agar that contained fatty acids. LAS ATCC 43504, 51932, and 700392 and the FIS IMMi 88, 89, and 92, each with <10 subcultures, were cultured in parallel on a fatty acid-free agar (ISAF) and on 5% sheep blood agar (SBA), which contained oleic acid (18:1 9c), hexadecanoic acid (16:0), and octadecanoic acid (18:0). ISAF-grown cultures showed no 18:1 9c and no appreciable differences between the profiles of FIS and LAS. After culture on SBA, the strains showed 18:1 9c and increased 16:0 and 18:0 content combined with decreased tetradecanoic acid (14:0) content compared to ISAF-grown cells. The changes in the fatty acid profiles were much more pronounced in FIS than in LAS. LAS are obviously characterized by a lower uptake of the fatty acids from the growth medium than FIS. Furthermore, it could be shown that this LAS behavior is most likely a primary strain attribute that is favored under laboratory conditions. The pronounced uptake of fatty acids by strains with FIS behavior may be associated with the expression of virulence properties.