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1.
J Am Chem Soc ; 146(12): 8435-8446, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38482664

RESUMO

Molybdenum alkylidyne N-heterocyclic carbene (NHC) complexes of the type [Mo(C-p-C6H4Y)(OC(R)(CF3)2)2 (L)(NHC)][B(ArF)4] (Y = OMe, NO2; R = CH3, CF3; L = none, pivalonitrile, tetrahydrofuran; NHC = 1,3-dimesitylimidazol-2-ylidene (IMes), 1,3-dimesityl-3,4-dihydroimidazol-2-ylidene (IMesH2), 1,3-dimesityl-3,4-dichloroimidazol-2-ylidene (IMesCl2), 1,3-diisopropylimidazol-2-ylidene (IiPr); B(ArF)4- = tetrakis(3,5-bis(trifluoromethyl)phen-1-yl)borate) were used in the ring expansion metathesis polymerization (REMP) of cyclic olefins. With cis-cyclooctene (cCOE) cyclic, low molecular weight oligomers were obtained at low monomer concentrations and the cyclic nature of the polymer was confirmed by MALDI-TOF measurements. High-molecular weight cyclic poly(cCOE) became available at high monomer concentrations. Also, post-REMP allowed for converting low-molecular-weight cyclic poly(cCOE) into high-molecular-weight cyclic poly(cCOE). Tailored catalysts together with suitable additives offered access to the stereoselective REMP of functional norbornenes providing functional cis-isotactic (cis-it), cis-syndiotactic (cis-st) and trans-it poly(norbornene)s with up to 99% stereoselectivity. Mechanistic details supported by density functional theory (DFT) calculations are outlined.

2.
J Ind Microbiol Biotechnol ; 48(7-8)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34323925

RESUMO

Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by fungi of the Ustilaginaceae family in the presence of hydrophobic carbon sources like plant oils. In the present study, we investigated the structural composition of MELs produced from castor oil using seven different microorganisms and compared them to MEL structures resulting from other plant oils. Castor oil is an industrially relevant plant oil that presents as an alternative to currently employed edible plant oils like rapeseed or soybean oil. The main fatty acid in castor oil is the mono-hydroxylated ricinoleic acid, providing the possibility to produce novel MEL structures with interesting features. Analysis of the produced MELs from castor oil by different chromatographic and mass spectrometry techniques revealed that all seven microorganisms were generally able to integrate hydroxylated fatty acids into the MEL molecule, although at varying degrees. These novel MELs containing a hydroxy fatty acid (4-O-[2'-O-alka(e)noyl-3'-O-hydroxyalka(e)noyl-4'/6'-O-acetyl-ß-D-mannopyranosyl]-erythritol) were more hydrophilic than conventional MEL and therefore showed a different elution behavior in chromatography. Large shares of novel hydroxy MELs (around 50% of total MELs) were found for the two MEL-B/C producing species Ustilago siamensis and Ustilago shanxiensis, but also for the MEL-A/B/C producer Moesziomyces aphidis (around 25%). In addition, tri-acylated hydroxylated MELs with a third long-chain fatty acid esterified to the free hydroxyl group of the hydroxy fatty acid were identified for some species. Overall, production of MEL from castor oil with the investigated organisms provided a complex mixture of various novel MEL structures that can be exploited for further research.


Assuntos
Óleo de Rícino , Tensoativos , Basidiomycota , Glicolipídeos
3.
Rheumatol Int ; 40(6): 893-899, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32240350

RESUMO

OBJECTIVES: X-ray is the fundamental imaging technique in both diagnosis and follow-up of rheumatic diseases. As patients often require sequential X-rays over many years, dose reduction is of great importance. New advanced noise reduction algorithms allow for a dose reduction of up to 50%. The aim of this study was to evaluate whether quality of low-dose images is non-inferior to standard-dose images and, therefore, application of this technique is possible in the context of imaging of rheumatic diseases. METHODS: A total of 298 patients with known or suspected rheumatic disease were enrolled prospectively into this study, separated into three consecutive groups: 80%, 64% and 50% tube charge reduction. All patients received imaging of one hand (laterality randomly assigned) with low-dose technique and imaging of the contralateral hand with standard-dose protocol. Images were evaluated by two independent readers who scored (on a scale of 1-5) the visualization of bony cortex, trabeculae and joint spaces of fingers and wrist separately. Additionally, soft tissue and overall contrast were evaluated on the same scale. RESULTS: Overall image quality (expressed by mean sum score out of 40) of the 50% low-dose images was 31.52 (SD 1.94) vs. 31.66 (SD 1.82) for standard images (p = 0.068). Bony contours as well as trabeculae were equally well visualized in both image sets. Median scores for soft tissue visualization was slightly lower for low dose compared to standard images [4 (IQR 3.5-4) vs. 4 (IQR 3.88-4); p = 0.001]. CONCLUSIONS: Overall image quality of low-dose images was not inferior to standard-dose images. Therefore, the application of low-dose technology based on advanced noise estimation algorithms in the context of imaging of rheumatic diseases is possible.


Assuntos
Doenças Reumáticas , Tomografia Computadorizada por Raios X , Humanos , Algoritmos , Dedos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Doenças Reumáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
4.
BMC Musculoskelet Disord ; 21(1): 20, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31926549

RESUMO

BACKGROUND: Lateral tibial split fractures (LTSF) usually require surgical therapy with screw or plate osteosynthesis. Excellent anatomical reduction of the fracture is thereby essential to avoid post-traumatic osteoarthritis. In clinical practice, a gap and step of 2 mm have been propagated as maximum tolerable limit. To date, biomechanical studies regarding tibial fractures have been limited to pressure measurement, but the relationship between dissipated energy (DE) as a friction parameter and reduction accuracy in LTSF has not been investigated. In past experiments, we developed a new method to measure DE in ovine knee joints. To determine weather non-anatomical fracture reduction with lateral gap or vertical step condition leads to relevant changes in DE in the human knee joint, we tested the applicability of the new method on human LTSFs and investigated whether the current limit of 2 mm gap and step is durable from a biomechanical point of view. METHODS: Seven right human, native knee joint specimens were cyclically moved under 400 N axial load using a robotic system. During the cyclic motion, the flexion angle and the respective torque were recorded and the DE was calculated. First, DE was measured after an anterolateral approach had been performed (condition "native"). Then a LTSF was set with a chisel, reduced anatomically, fixed with two set screws and DE was measured ("even"). DE of further reductions was then measured with gaps of 1 mm and 2 mm, and a 2 mm step down or a 2 mm step up was measured. RESULTS: We successfully established a measurement protocol for DE in human knee joints with LTSF. While gaps led to small though statistically significant increase (1 mm gap:ΔDE compared with native = 0.030 J/cycle, (+ 21%), p = 0.02; 2 mm gap:ΔDE = 0.032 J/cycle, (+ 22%), p = 0.009), this increase almost doubled when reducing in a step-down condition (ΔDE = 0.058 J/cycle, (+ 56%), p = 0.042) and even tripled in the step-up condition (ΔDE = 0.097 J/cycle, (+ 94%), p = 0.004). CONCLUSIONS: Based on our biomechanical findings, we suggest avoiding step conditions in the daily work in the operating theatre. Gap conditions can be handled a bit more generously.


Assuntos
Fixação Interna de Fraturas/métodos , Articulação do Joelho/fisiopatologia , Fraturas da Tíbia/cirurgia , Humanos , Fraturas da Tíbia/fisiopatologia
5.
J Ind Microbiol Biotechnol ; 46(8): 1191-1204, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31175524

RESUMO

Mannosylerythritol lipids (MEL) are microbial glycolipid biosurfactants with great potential for application in cosmetics and household detergents. In current biotechnological processes, they are produced by basidiomycetous fungi, the Ustilaginaceae, as a complex mixture of different chemical structures. It was the aim of this paper to study the influence of producer organisms and substrates on the resulting MEL structures with a novel high-resolution HPTLC-MALDI-TOF method. Given the seven different microbes and four plant oils, our analysis revealed that the product concentrations varied strongly between organisms, while they were similar for the different substrates. Coconut oil presented an exception, since only one organism was able to synthesize MEL from this substrate in considerable yields. Analysis by GC-FID further showed that the chain length pattern of hydrophobic fatty acid side-chains was very specific for individual organisms, while substrates had only a minor influence on the chain length. Our novel HPTLC-MALDI-TOF combination method finally demonstrated the presence of multiple MEL sub-variants with differing acetylation and fatty acid chain lengths. It also revealed the production of a more hydrophilic biosurfactant mannosylmannitol lipid (MML) as a side-product in certain fungi. Overall, it was concluded that the pattern of produced biosurfactant structures are mainly governed by producer organisms rather than substrates.


Assuntos
Cromatografia em Camada Fina/métodos , Glicolipídeos/química , Glicolipídeos/metabolismo , Óleos de Plantas/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Ustilaginales/metabolismo , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Óleos de Plantas/química , Tensoativos/química , Tensoativos/metabolismo , Ustilaginales/genética
6.
J Hepatol ; 61(6): 1312-20, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25135868

RESUMO

BACKGROUND & AIMS: Hepatoblastoma (HB) is the most common childhood liver cancer and occasionally presents with histological and clinical features reminiscent of hepatocellular carcinoma (HCC). Identification of molecular mechanisms that drive the neoplastic continuation towards more aggressive HCC phenotypes may help to guide the new stage of targeted therapies. METHODS: We performed comprehensive studies on genetic and chromosomal alterations as well as candidate gene function and their clinical relevance. RESULTS: Whole-exome sequencing identified HB as a genetically very simple tumour (2.9 mutations per tumour) with recurrent mutations in ß-catenin (CTNNB1) (12/15 cases) and the transcription factor NFE2L2 (2/15 cases). Their HCC-like progenies share the common CTNNB1 mutation, but additionally exhibit a significantly increased mutation number and chromosomal instability due to deletions of the genome guardians RAD17 and TP53, accompanied by telomerase reverse-transcriptase (TERT) promoter mutations. Targeted genotyping of 33 primary tumours and cell lines revealed CTNNB1, NFE2L2, and TERT mutations in 72.5%, 9.8%, and 5.9% of cases, respectively. All NFE2L2 mutations affected residues of the NFE2L2 protein that are recognized by the KEAP1/CUL3 complex for proteasomal degradation. Consequently, cells transfected with mutant NFE2L2 were insensitive to KEAP1-mediated downregulation of NFE2L2 signalling. Clinically, overexpression of the NFE2L2 target gene NQO1 in tumours was significantly associated with metastasis, vascular invasion, the adverse prognostic C2 gene signature, as well as poor outcome. CONCLUSIONS: Our study demonstrates the importance of CTNNB1 mutations and NFE2L2-KEAP1 pathway activation in HB development and defines loss of genomic stability and TERT promoter mutations as prominent characteristics of aggressive HB with HCC features.


Assuntos
Carcinoma Hepatocelular/genética , Genômica , Hepatoblastoma/genética , Neoplasias Hepáticas/genética , Análise de Sequência de DNA , Adulto , Biópsia , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Criança , DNA de Neoplasias/genética , Hepatoblastoma/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteína 1 Associada a ECH Semelhante a Kelch , Neoplasias Hepáticas/patologia , Mutação/genética , Fator 2 Relacionado a NF-E2/genética , Estudos Retrospectivos , Telomerase/genética , beta Catenina/genética
7.
J Sci Food Agric ; 94(13): 2582-94, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24375441

RESUMO

In 2007 EU Regulation (EC) 834/2007 introduced principles and criteria for organic food processing. These regulations have been analysed and discussed in several scientific publications and research project reports. Recently, organic food quality was described by principles, aspects and criteria. These principles from organic agriculture were verified and adapted for organic food processing. Different levels for evaluation were suggested. In another document, underlying paradigms and consumer perception of organic food were reviewed against functional food, resulting in identifying integral product identity as the underlying paradigm and a holistic quality view connected to naturalness as consumers' perception of organic food quality. In a European study, the quality concept was applied to the organic food chain, resulting in a problem, namely that clear principles and related criteria were missing to evaluate processing methods. Therefore the goal of this paper is to describe and discuss the topic of organic food processing to make it operational. A conceptual background for organic food processing is given by verifying the underlying paradigms and principles of organic farming and organic food as well as on organic processing. The proposed definition connects organic processing to related systems such as minimal, sustainable and careful, gentle processing, and describes clear principles and related criteria. Based on food examples, such as milk with different heat treatments, the concept and definitions were verified. Organic processing can be defined by clear paradigms and principles and evaluated according criteria from a multidimensional approach. Further work has to be done on developing indicators and parameters for assessment of organic food quality.


Assuntos
Defesa do Consumidor , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos , Qualidade dos Alimentos , Alimentos Orgânicos/análise , Modelos Biológicos , Agricultura Orgânica , Criação de Animais Domésticos/métodos , Criação de Animais Domésticos/normas , Bem-Estar do Animal/tendências , Animais , Biomarcadores/análise , Defesa do Consumidor/tendências , Indústria de Laticínios/métodos , Indústria de Laticínios/normas , União Europeia , Manipulação de Alimentos/normas , Conservação de Alimentos/métodos , Conservação de Alimentos/normas , Alimentos Orgânicos/microbiologia , Alimentos Orgânicos/normas , Humanos , Legislação sobre Alimentos , Agricultura Orgânica/normas
8.
Radiol Oncol ; 48(4): 339-47, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25435846

RESUMO

BACKGROUND: To evaluate the clinical efficacy of In-111 DTPA octreotide SPECT/CT and Ga-68 DOTATOC PET/CT for detection of primary tumors in patients with either neuroendocrine tumor of unknown primary (NETUP) or clinically suspected primary NET (SNET). PATIENTS AND METHODS: A total of 123 patients were included from 2006 to 2009, 52 received Ga-68 DOTATOC PET/CT (NETUP, 33; SNET, 19) and 71 underwent In-111 DTPA octreotide SPECT/CT (50; 21). The standard of reference included histopathology or clinical verification based on follow-up examinations. RESULTS: In the NETUP group Ga-68 DOTATOC detected primaries in 15 patients (45.5%) and In-111 DTPA octreotide in 4 patients (8%) (p < 0.001); in the SNET group, only 2 primaries could be detected, all by Ga-68 DOTATOC. In patients with NETUP, primary tumors could be found significantly more often than in patients with SNET (p = 0.01). Out of these 21 patients 14 patients were operated. CONCLUSION: Ga-68 DOTATOC PET/CT is preferable to In-111 DTPA octreotide SPECT/CT when searching for primary NETs in patients with NETUP but should be used with caution in patients with SNET.

9.
Front Bioeng Biotechnol ; 12: 1347452, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38464544

RESUMO

Introduction: This study assesses the environmental impacts of mannosylerythritol lipids (MELs) production for process optimization using life cycle assessment (LCA). MELs are glycolipid-type microbial biosurfactants with many possible applications based on their surface-active properties. They are generally produced by fungi from the family of Ustilaginaceae via fermentation in aerated bioreactors. The aim of our work is to accompany the development of biotechnological products at an early stage to enable environmentally sustainable process optimization. Methods: This is done by identifying hotspots and potentials for improvement based on a reliable quantification of the environmental impacts. The production processes of MELs are evaluated in a cradle-to-gate approach using the Environmental Footprint (EF) 3.1 impact assessment method. The LCA model is based on upscaled experimental data for the fermentation and purification, assuming the production at a 10 m³ scale. In the case analyzed, MELs are produced from rapeseed oil and glucose, and purified by separation, solvent extraction, and chromatography. Results: The results of the LCA show that the provision of substrates is a major source of environmental impacts and accounts for 20% of the impacts on Climate Change and more than 70% in the categories Acidification and Eutrophication. Moreover, 33% of the impacts on Climate Change is caused by the energy requirements for aeration of the bioreactor, while purification accounts for 42% of the impacts respectively. For the purification, solvents are identified as the main contributors in most impact categories. Discussion: The results illustrate the potentials for process optimization to reduce the environmental impacts of substrate requirements, enhanced bioreactor aeration, and efficient solvent use in downstream processing. By a scenario analysis, considering both experimental adaptations and prospective variations of the process, the laboratory development can be supported with further findings and hence efficiently optimized towards environmental sustainability. Moreover, the presentation of kinetic LCA results over the fermentation duration shows a novel way of calculating and visualizing results that corresponds to the way of thinking of process engineers using established environmental indicators and a detailed system analysis. Altogether, this LCA study supports and demonstrates the potential for further improvements towards more environmentally friendly produced surfactants.

10.
J Neurol Surg A Cent Eur Neurosurg ; 84(1): 91-94, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35668672

RESUMO

BACKGROUND: Spinal tuberculosis is a manifestation of extrapulmonary tuberculosis. The incidence of tuberculosis is low in high-income countries; however, globally, it still remains one of the most frequent fatal infectious diseases. Because of its rarity in developed countries, spinal tuberculosis can be mistaken for malignant tumors of the spine, especially in case of an atypical radiologic manifestation and without pulmonary affection. METHODS: We present the case of a 39-year-old man from South India with quickly progressing gait disturbance and hypesthesia below the Th10 level. Magnetic resonance imaging revealed an osteolytic lesion of the vertebral arch Th2 with central necrosis and compression of the spinal cord altogether highly suspicious for spinal metastasis. RESULTS: After surgical removal of the mass by laminectomy, the patient regained normal neurologic function. Histology revealed a severe granulomatous inflammation and DNAhybridization of polymerase chain reaction (PCR) products detected Mycobacterium tuberculosis-specific DNA in the sample. Biopsy of an enlarged hilar lymphnode allowed us to obtain material to successfully perform a drug resistance test to start specific antimicrobial therapy. CONCLUSION: Spinal tuberculosis, even with atypical radiologic appearance, has to be considered a differential diagnosis in patients with provenance from endemic countries. A multidisciplinary diagnostic approach helps perform antimicrobial susceptibility testing to avoid delaying the start of antibiotic therapy.


Assuntos
Neoplasias da Coluna Vertebral , Tuberculose da Coluna Vertebral , Masculino , Humanos , Adulto , Tuberculose da Coluna Vertebral/diagnóstico por imagem , Tuberculose da Coluna Vertebral/tratamento farmacológico , Tuberculose da Coluna Vertebral/cirurgia , Corpo Vertebral/patologia , Corpo Vertebral/cirurgia , Coluna Vertebral/cirurgia , Laminectomia/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/cirurgia
11.
Eur J Cancer ; 178: 37-48, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36399909

RESUMO

BACKGROUND: In patients with RAS wild-type metastatic colorectal cancer, depth of response (DpR) has gained importance as a novel end-point in clinical trials. We investigated the overall DpR, as well as the prognostic and predictive impact of DpR to induction therapy (six cycles of 5-fluorouracil, leucovorin [FU/FA], oxaliplatin [FOLFOX] and panitumumab [Pmab]) on consecutive maintenance therapy (FU/FA plus Pmab or FU/FA alone) in patients treated within the PanaMa trial. METHODS: Central radiological assessment was performed according to RECIST 1.1. DpR was defined as percentage change in tumour diameter within defined time intervals (induction therapy, maintenance therapy, total course of therapy). For prognostic and predictive analyses, median DpR (

Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Neoplasias Retais , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Fluoruracila/uso terapêutico , Quimioterapia de Indução , Leucovorina/uso terapêutico , Panitumumabe , Neoplasias Retais/tratamento farmacológico
12.
Sci Adv ; 9(43): eadi8986, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37889970

RESUMO

Various cellular sources hamper interpretation of positron emission tomography (PET) biomarkers in the tumor microenvironment (TME). We developed an approach of immunomagnetic cell sorting after in vivo radiotracer injection (scRadiotracing) with three-dimensional (3D) histology to dissect the cellular allocation of PET signals in the TME. In mice with implanted glioblastoma, translocator protein (TSPO) radiotracer uptake per tumor cell was higher compared to tumor-associated microglia/macrophages (TAMs), validated by protein levels. Translation of in vitro scRadiotracing to patients with glioma immediately after tumor resection confirmed higher single-cell TSPO tracer uptake of tumor cells compared to immune cells. Across species, cellular radiotracer uptake explained the heterogeneity of individual TSPO-PET signals. In consideration of cellular tracer uptake and cell type abundance, tumor cells were the main contributor to TSPO enrichment in glioblastoma; however, proteomics identified potential PET targets highly specific for TAMs. Combining cellular tracer uptake measures with 3D histology facilitates precise allocation of PET signals and serves to validate emerging novel TAM-specific radioligands.


Assuntos
Glioblastoma , Glioma , Humanos , Camundongos , Animais , Glioblastoma/diagnóstico por imagem , Glioblastoma/metabolismo , Microambiente Tumoral , Glioma/patologia , Tomografia por Emissão de Pósitrons/métodos , Microglia/metabolismo , Proteínas de Transporte/metabolismo , Receptores de GABA/metabolismo
13.
Vasa ; 41(2): 132-5, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22403132

RESUMO

The mid-aortic syndrome is an uncommon clinical condition characterized by severe narrowing of the descending aorta, usually with involvement of its renal and visceral branches, presenting with uncontrollably elevated blood pressures of the upper body, renal and cardiac failure, intestinal ischemia, encephalopathy symptoms and claudication of the lower limbs, although clinical presentation is variable. In this article we report the case of an eleven-year-old patient with the initial diagnosis of a mid-aortic syndrome and present the computed tomography angiography pictures and reconstructions before and after surgical therapy.


Assuntos
Aorta Torácica/diagnóstico por imagem , Coartação Aórtica/diagnóstico por imagem , Aortografia/métodos , Circulação Colateral , Tomografia Computadorizada por Raios X , Aorta Torácica/fisiopatologia , Aorta Torácica/cirurgia , Coartação Aórtica/complicações , Coartação Aórtica/fisiopatologia , Coartação Aórtica/cirurgia , Pressão Sanguínea , Implante de Prótese Vascular , Criança , Humanos , Masculino , Valor Preditivo dos Testes , Fluxo Sanguíneo Regional , Resultado do Tratamento
14.
Front Bioeng Biotechnol ; 10: 913362, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35656195

RESUMO

Mannosylerythritol lipids are glycolipid biosurfactants with many interesting properties. Despite the general interest in those molecules and the need for a robust process, studies on their production in bioreactors are still scarce. In the current study, the fermentative production of MEL in a bioreactor with Moesziomyces aphidis was performed using a defined mineral salt medium. Several kinetic process parameters like substrate consumption rates and product formation rates were evaluated and subsequently enhanced by increasing the biomass concentration through an exponential fed-batch strategy. The fed-batch approaches resulted in two to three fold increased dry biomass concentrations of 10.9-15.5 g/L at the end of the growth phase, compared with 4.2 g/L in the batch process. Consequently, MEL formation rates were increased from 0.1 g/Lh up to around 0.4 g/Lh during the MEL production phase. Thus, a maximum concentration of up to 50.5 g/L MEL was obtained when oil was added in excess, but high concentrations of residual fatty acids were also present in the broth. By adjusting the oil feeding to biomass-specific hydrolysis and MEL production rates, a slightly lower MEL concentration of 34.3 g/L was obtained after 170 h, but at the same time a very pure crude lipid extract with more than 90% MEL and a much lower concentration of remaining fatty acids. With rapeseed oil as substrate, the ideal oil-to-biomass ratio for full substrate conversion was found to be around 10 goil/gbiomass. In addition, off-gas analysis and pH trends could be used to assess biomass growth and MEL production. Finally, kinetic models were developed and compared to the experimental data, allowing for a detailed prediction of the process behavior in future experiments.

15.
Br J Radiol ; 95(1130): 20210881, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34919419

RESUMO

OBJECTIVES: Radiography remains the mainstay of diagnostic and follow-up imaging. In view of the risks and the increasing use of ionizing radiation, dose reduction is a key issue for research and development. The introduction of digital radiography and the associated access to image postprocessing have opened up new opportunities to minimize the radiation dosage. These advances are contingent upon quality controls to ensure adequate image detail and maintenance of diagnostic confidence. The purpose of this study was to investigate the clinical applicability of postprocessed low-dose images in skeletal radiography. METHODS: In our study setting, the median radiation dose for full dose X-rays was 9.61 dGy*cm2 for pelvis, 1.20 dGy*cm2 for shoulder and 18.64 dGy*cm2 for lumbar spine exams. Based on these values, we obtained 200 radiographs for each anatomic region in four consecutive steps, gradually reducing the dose to 84%, 71%, 60% and 50% of the baseline using an automatic exposure control (AEC). 549 patients were enrolled for a total of 600 images. All X-rays were postprocessed with a spatial noise reduction algorithm. Two radiologists assessed the diagnostic value of the radiographs by rating the visualization of anatomical landmarks and image elements on a five-point Likert scale. A mean-sum score was calculated by averaging the two reader's total scores. Given the non-parametric distribution, we used the Mann-Whitney U test to evaluate the scores. RESULTS: Median dosage at full dose accounted for 38.4%, 48 and 53.2% of the German reference dose area product for shoulder, pelvis and lumbar spine, respectively. The applied radiation was incrementally reduced to 21.5%, 18.4% and 18.7% of the respective reference value for shoulder, pelvis and lumbar spine. Throughout the study, we observed an estimable tendency of superior quality at higher dosage in overall image quality. Statistically significant differences in image quality were restricted to the 50% dose groups in shoulder and lumbar spine images. Regardless of the applied dosage, 598 out of 600 images were of sufficient diagnostic value. CONCLUSION: In digital radiography image postprocessing allows for extensive reduction of radiation dosage. Despite a trend of superior image detail at higher dose levels, overall quality and, more importantly, diagnostic utility of low-dose images was not significantly affected. Therefore, our results not only confirm the clinical utility of postprocessed low-dose radiographs, but also suggest a widespread deployment of this advanced technology to ensure further dose limitations in clinical practice. ADVANCES IN KNOWLEDGE: The diagnostic image quality of postprocessed skeletal radiographs is not significantly impaired even after extensive dose reduction by up to 20% of the reference value.


Assuntos
Vértebras Lombares/diagnóstico por imagem , Ossos Pélvicos/diagnóstico por imagem , Doses de Radiação , Intensificação de Imagem Radiográfica , Ombro/diagnóstico por imagem , Algoritmos , Osso e Ossos/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exposição à Radiação/prevenção & controle , Intensificação de Imagem Radiográfica/normas , Radiografia/estatística & dados numéricos , Valores de Referência , Estatísticas não Paramétricas
16.
Nat Genet ; 54(12): 1881-1894, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36471067

RESUMO

Histone 3 lysine27-to-methionine (H3-K27M) mutations most frequently occur in diffuse midline gliomas (DMGs) of the childhood pons but are also increasingly recognized in adults. Their potential heterogeneity at different ages and midline locations is vastly understudied. Here, through dissecting the single-cell transcriptomic, epigenomic and spatial architectures of a comprehensive cohort of patient H3-K27M DMGs, we delineate how age and anatomical location shape glioma cell-intrinsic and -extrinsic features in light of the shared driver mutation. We show that stem-like oligodendroglial precursor-like cells, present across all clinico-anatomical groups, display varying levels of maturation dependent on location. We reveal a previously underappreciated relationship between mesenchymal cancer cell states and age, linked to age-dependent differences in the immune microenvironment. Further, we resolve the spatial organization of H3-K27M DMG cell populations and identify a mitotic oligodendroglial-lineage niche. Collectively, our study provides a powerful framework for rational modeling and therapeutic interventions.


Assuntos
Glioma , Humanos , Criança , Glioma/genética , Histonas/genética , Metionina , Mutação , Racemetionina , Microambiente Tumoral/genética
17.
Cancer Discov ; 12(12): 2880-2905, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36305736

RESUMO

Diffuse midline gliomas are uniformly fatal pediatric central nervous system cancers that are refractory to standard-of-care therapeutic modalities. The primary genetic drivers are a set of recurrent amino acid substitutions in genes encoding histone H3 (H3K27M), which are currently undruggable. These H3K27M oncohistones perturb normal chromatin architecture, resulting in an aberrant epigenetic landscape. To interrogate for epigenetic dependencies, we performed a CRISPR screen and show that patient-derived H3K27M-glioma neurospheres are dependent on core components of the mammalian BAF (SWI/SNF) chromatin remodeling complex. The BAF complex maintains glioma stem cells in a cycling, oligodendrocyte precursor cell-like state, in which genetic perturbation of the BAF catalytic subunit SMARCA4 (BRG1), as well as pharmacologic suppression, opposes proliferation, promotes progression of differentiation along the astrocytic lineage, and improves overall survival of patient-derived xenograft models. In summary, we demonstrate that therapeutic inhibition of the BAF complex has translational potential for children with H3K27M gliomas. SIGNIFICANCE: Epigenetic dysregulation is at the core of H3K27M-glioma tumorigenesis. Here, we identify the BRG1-BAF complex as a critical regulator of enhancer and transcription factor landscapes, which maintain H3K27M glioma in their progenitor state, precluding glial differentiation, and establish pharmacologic targeting of the BAF complex as a novel treatment strategy for pediatric H3K27M glioma. See related commentary by Beytagh and Weiss, p. 2730. See related article by Mo et al., p. 2906.


Assuntos
Epigenoma , Glioma , Animais , Humanos , Mutação , Glioma/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Células-Tronco Neoplásicas/metabolismo , Mamíferos/genética , Mamíferos/metabolismo , DNA Helicases/genética , Proteínas Nucleares/genética
18.
EMBO J ; 26(22): 4619-33, 2007 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-17962809

RESUMO

Protein kinase D2 (PKD2), a member of the PKD family of serine/threonine kinases, is localized in various subcellular compartments including the nucleus where the kinase accumulates upon activation of G-protein-coupled receptors. We define three critical post-translational modifications required for nuclear accumulation of PKD2 in response to activation of the CCK2 receptor (CCK2R): phosphorylation at Ser706 and Ser710 within the activation loop by PKC eta leading to catalytic activity and phosphorylation at Ser244 within the zinc-finger domain, which is crucial for blocking nuclear export of active PKD2 by preventing its interaction with the Crm-1 export machinery. We identify CK1delta and epsilon as upstream activated kinases by CCK2R that phosphorylate PKD2 at Ser244. Moreover, nuclear accumulation of active PKD2 is a prerequisite for efficient phosphorylation of its nuclear substrate, HDAC7. Only nuclear, active PKD2 mediates CCK2R-induced HDAC7 phosphorylation and Nur77 expression. Thus, we define a novel, compartment-specific signal transduction pathway downstream of CCK2R that phosphorylates PKD2 at three specific sites, results in nuclear accumulation of the active kinase and culminates in efficient phosphorylation of nuclear PKD2 substrates in human gastric cancer cells.


Assuntos
Caseína Quinase 1 épsilon/metabolismo , Caseína Quinase Idelta/metabolismo , Proteínas Quinases/metabolismo , Receptor de Colecistocinina B/metabolismo , Animais , Células COS , Linhagem Celular , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Chlorocebus aethiops , Proteínas de Ligação a DNA/metabolismo , Gastrinas/farmacologia , Células HeLa , Histona Desacetilases/metabolismo , Humanos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares , Fosforilação , Proteína Quinase C/metabolismo , Proteína Quinase D2 , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores de Esteroides/metabolismo , Serina/metabolismo , Fatores de Transcrição/metabolismo
19.
Cerebrovasc Dis ; 32(3): 207-10, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21822012

RESUMO

BACKGROUND: Prehospital cooling of acute stroke patients would be ideal when associated with minor or no side effects. Therefore, we evaluated a cooling cap for the surface of head and cervical regions in awake volunteers. METHODS: 10 healthy volunteers were treated by external cooling for 190 min using a gel-based cooling device. Vital signs, rectal temperature, tympanic temperature, the extent of shivering and individual perception of frostiness and discomfort were measured. RESULTS: All participants (median age 35 years) successfully completed the treatment and experienced only mild to moderate discomfort. No serious adverse events and no shivering were noticed. There was a significant drop in the tympanic temperature to 34.68°C (difference from baseline: 1.7°C, 95% CI: 0.61-2.7°C, p = 0.001), in the rectal temperature to 36.65°C (difference from baseline: 0.65°C, 95% CI: 0.06-1.2°C, p = 0.019) and in the heart rate (difference from baseline: 15 beats/min, 95% CI: 0.63-30 beats/min, p = 0.035). CONCLUSION: Treatment with the cooling device was well tolerated by all participants. The technique had measurable effects on core body temperature (rectal) and tympanic temperature (may reflect temperature at the external ear and skin rather than intracranial). It can be considered as a simple therapeutic approach to patients with suspected stroke in the prehospital setting.


Assuntos
Regulação da Temperatura Corporal , Hipotermia Induzida/instrumentação , Adulto , Análise de Variância , Pressão Sanguínea , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Alemanha , Cabeça , Frequência Cardíaca , Humanos , Hipotermia Induzida/efeitos adversos , Masculino , Pescoço , Fatores de Tempo
20.
Cerebrovasc Dis ; 31(4): 382-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21266804

RESUMO

BACKGROUND: Fever after acute cerebral injury is associated with unfavorable functional outcome and increased mortality, but there is controversy about the optimal antipyretic treatment. This study investigated an institutional standard operating procedure (SOP) for fever treatment in stroke patients including a sequence of pharmacologic and physical interventions. METHODS: A 4-step antipyretic SOP was established for patients with acute cerebral ischemia or hemorrhage and a body temperature ≥37.5°C within the first 6 days after admission. Data on the course of body temperature, duration of fever and achievement of normothermia were recorded. Results were compared to a historic control group that underwent conventional treatment. RESULTS: A total of 77 patients (mean age 70.4 ± 14.2 years) received 331 antipyretic interventions. Sequential administration of paracetamol (n = 219), metamizole (n = 71) and calf packing (n = 24) resulted in a significant drop in body temperature after 60 min in each instance. In 5 of 9 cases which were refractory to previous attempts, normothermia followed the infusion of ice-cooled saline. In more than 90% of cases treated per protocol, normothermia was achieved within 120 min. Compared to conventional treatment, fever burden was significantly lower within the first 4 days after admission (p < 0.001). CONCLUSION: This SOP may help to optimize antipyretic treatment for stroke patients.


Assuntos
Antipiréticos/administração & dosagem , Regulação da Temperatura Corporal/efeitos dos fármacos , Procedimentos Clínicos/normas , Febre/terapia , Hipotermia Induzida/normas , Acidente Vascular Cerebral/terapia , Acetaminofen/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Antipiréticos/efeitos adversos , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Terapia Combinada , Dipirona/administração & dosagem , Feminino , Febre/diagnóstico , Febre/fisiopatologia , Alemanha , Humanos , Hipotermia Induzida/efeitos adversos , Infusões Intravenosas , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Avaliação de Programas e Projetos de Saúde , Cloreto de Sódio/administração & dosagem , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo , Resultado do Tratamento
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