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2.
Microsc Microanal ; 30(2): 294-305, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38507652

RESUMO

We present an efficient approach for electron ptychography based on a mathematical relationship that differs from that underlying the established algorithms of the ptychography iterative engine or the noniterative algorithms like the Wigner-distribution-deconvolution or the single-side-band method. Three variables are handled in this method-the transfer function of the objective lens, the object spectrum, and the diffraction wave whose phase is unknown. In the case of an aberration-corrected electron microscope, one is able to obtain a well-estimated transfer function of the lens. After reducing the number of three variables down to two, we construct an iterative loop between the object spectrum and the diffraction wave, which retrieves the object spectrum within a small number of iterations. We tested this object spectrum retrieval method on both a calculated and an experimental 4D-STEM datasets. By applying this method, we explore the influence of sampling, dose, and the size of illumination aperture on the reconstructed phase images.

3.
Blood ; 143(12): 1139-1156, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38064663

RESUMO

ABSTRACT: The World Health Organization (WHO) classification of hematolymphoid tumors and the International Consensus Classification (ICC) of 2022 introduced major changes to the definition of chronic myelomonocytic leukemia (CMML). To assess its qualitative and quantitative implications for patient care, we started with 3311 established CMML cases (according to WHO 2017 criteria) and included 2130 oligomonocytosis cases fulfilling the new CMML diagnostic criteria. Applying both 2022 classification systems, 356 and 241 of oligomonocytosis cases were newly classified as myelodysplastic (MD)-CMML (WHO and ICC 2022, respectively), most of which were diagnosed as myelodysplastic syndrome (MDS) according to the WHO 2017 classification. Importantly, 1.5 times more oligomonocytosis cases were classified as CMML according to WHO 2022 than based on ICC, because of different diagnostic criteria. Genetic analyses of the newly classified CMML cases showed a distinct mutational profile with strong enrichment of MDS-typical alterations, resulting in a transcriptional subgroup separated from established MD and myeloproliferative CMML. Despite a different cytogenetic, molecular, immunophenotypic, and transcriptional landscape, no differences in overall survival were found between newly classified and established MD-CMML cases. To the best of our knowledge, this study represents the most comprehensive analysis of routine CMML cases to date, both in terms of clinical characterization and transcriptomic analysis, placing newly classified CMML cases on a disease continuum between MDS and previously established CMML.


Assuntos
Leucemia Mielomonocítica Crônica , Síndromes Mielodisplásicas , Humanos , Consenso , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Leucemia Mielomonocítica Crônica/diagnóstico , Leucemia Mielomonocítica Crônica/genética , Leucemia Mielomonocítica Crônica/patologia , Leucocitose , Organização Mundial da Saúde , Prognóstico , Compostos Orgânicos
4.
Blood ; 142(25): 2175-2191, 2023 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-37756525

RESUMO

ABSTRACT: Growth factor independence 1 (GFI1) is a DNA-binding transcription factor and a key regulator of hematopoiesis. GFI1-36N is a germ line variant, causing a change of serine (S) to asparagine (N) at position 36. We previously reported that the GFI1-36N allele has a prevalence of 10% to 15% among patients with acute myeloid leukemia (AML) and 5% to 7% among healthy Caucasians and promotes the development of this disease. Using a multiomics approach, we show here that GFI1-36N expression is associated with increased frequencies of chromosomal aberrations, mutational burden, and mutational signatures in both murine and human AML and impedes homologous recombination (HR)-directed DNA repair in leukemic cells. GFI1-36N exhibits impaired binding to N-Myc downstream-regulated gene 1 (Ndrg1) regulatory elements, causing decreased NDRG1 levels, which leads to a reduction of O6-methylguanine-DNA-methyltransferase (MGMT) expression levels, as illustrated by both transcriptome and proteome analyses. Targeting MGMT via temozolomide, a DNA alkylating drug, and HR via olaparib, a poly-ADP ribose polymerase 1 inhibitor, caused synthetic lethality in human and murine AML samples expressing GFI1-36N, whereas the effects were insignificant in nonmalignant GFI1-36S or GFI1-36N cells. In addition, mice that received transplantation with GFI1-36N leukemic cells treated with a combination of temozolomide and olaparib had significantly longer AML-free survival than mice that received transplantation with GFI1-36S leukemic cells. This suggests that reduced MGMT expression leaves GFI1-36N leukemic cells particularly vulnerable to DNA damage initiating chemotherapeutics. Our data provide critical insights into novel options to treat patients with AML carrying the GFI1-36N variant.


Assuntos
Proteínas de Ligação a DNA , Leucemia Mieloide Aguda , Humanos , Camundongos , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Temozolomida , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Dano ao DNA , Reparo do DNA , Células Germinativas/metabolismo , DNA , Fatores de Transcrição/genética
7.
Micron ; 174: 103525, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37595407

RESUMO

Despite the exceptional resolution in aberration-corrected high-resolution transmission electron microscope (AC-HRTEM) images of inorganic two-dimensional (2D) materials, achieving high-resolution imaging of organic 2D materials remains a daunting challenge due to their low electron resilience. Optimizing the critical dose (the electron exposure, the material can accept before it is noticeably damaged) is vital to mitigate this challenge. An understanding of electron resilience in porous crystalline 2D polymers including the effect of sample thickness has not been derived thus far. It is assumed, that additional layers of the sample form a cage around inner layers, which are preventing fragments from escaping into the vacuum and enabling recombination. In the literature this so called caging effect has been reported for perylene and pythalocyanine. In this work we determine the critical dose of a porous, triazine-based 2D polymer as function of the sample thickness. The results show that the caging effect should not be generalized to more sophisticated polymer systems. We argue that pore channels in the framework structure serve as escape routes for free fragments preventing the caging effect and thus showing surprisingly a thickness-independent critical dose. Moreover, we demonstrate that graphene encapsulation prevents fragment escape and results in an increase in the critical electron dose and unit-cell image resolution.

8.
Ultramicroscopy ; 253: 113805, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37459656

RESUMO

An electron monochromator design is presented as an instrumental development for electron energy loss spectroscopy (EELS) and imaging in (scanning) transmission electron microscopy ((S)TEM). The main purpose of this development is enhancing the energy resolving power in spectroscopy and filtering. In addition, it helps reducing the effect of the objective lens' chromatic aberration Cc in imaging and therefore, enhancing the spatial resolving power of electron microscopes. General estimates for the performance of a monochromator in energy distribution and the resulting usable beam currents are given. The special monochromator design presented is a ground-potential monochromator based on magnetic sector fields. The monochromator generates a spatially and angular un-dispersed spot and has no mechanically actuated parts in the filter sections. The optics can be operated at electron acceleration voltages from 30kV to 300kV and shows an energy resolving power of better than 2⋅10-7 relative to the primary electron energy. The actual device is designed to be retro-fittable to microscopes from various manufacturers.

10.
Respirology ; 28(5): 465-474, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36642509

RESUMO

BACKGROUND AND OBJECTIVE: In the INBUILD trial in patients with progressive fibrosing interstitial lung diseases (ILDs), nintedanib reduced the rate of decline in forced vital capacity (FVC) with an adverse event profile characterized mainly by gastrointestinal events. We analysed the effects of nintedanib in the subset of Asian subjects. METHODS: Subjects with fibrosing ILDs other than idiopathic pulmonary fibrosis who had shown progression of ILD at any time within the prior 24 months despite management deemed appropriate in clinical practice were randomized to receive nintedanib or placebo. We analysed the rate of decline in FVC (ml/year) over 52 weeks in all Asian subjects and in Asian subjects with a usual interstitial pneumonia (UIP)-like fibrotic pattern on high-resolution computed tomography (HRCT). RESULTS: One hundred sixty-four subjects in the INBUILD trial were of Asian race. The rate of decline in FVC (ml/year) over 52 weeks in this subgroup was -116.8 in the nintedanib group and -207.9 in the placebo group (difference: 91.0 [95% CI: 8.1, 173.9]; nominal p = 0.03). In Asian subjects with a UIP-like fibrotic pattern on HRCT, the rate of decline in FVC (ml/year) over 52 weeks was -130.1 in the nintedanib group and -224.2 in the placebo group (difference: 94.1 [5.5, 182.7]; nominal p = 0.04). Adverse events led to treatment discontinuation in 19.0% of the nintedanib group and 13.8% of the placebo group. CONCLUSION: In Asian patients with progressive fibrosing ILDs, nintedanib reduced the rate of decline in FVC with adverse events that were manageable for most patients.


Assuntos
Fibrose Pulmonar Idiopática , Doenças Pulmonares Intersticiais , Humanos , Progressão da Doença , Doenças Pulmonares Intersticiais/tratamento farmacológico , Fibrose Pulmonar Idiopática/tratamento farmacológico , Indóis/efeitos adversos , Capacidade Vital , Fibrose
13.
Neurol Res Pract ; 4(1): 44, 2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36131301

RESUMO

BACKGROUND: To mitigate the potential consequences of the coronavirus disease 2019 (COVID-19) pandemic on public life, the German Federal Government and Ministry of Health enacted a strict lockdown protocol on March 16, 2020. This study aimed to evaluate the impact of the COVID-19 pandemic on physical and mental health status and the supply of medical care and medications for people with epilepsy (PWE) in Germany. METHODS: The Epi2020 study was a large, multicenter study focused on different healthcare aspects of adults with epilepsy. In addition to clinical and demographic characteristics, patients were asked to answer a questionnaire on the impact of the first wave of the COVID-19 pandemic between March and May 2020. Furthermore, the population-based number of epilepsy-related admissions in Hessen was evaluated for the January-June periods of 2017-2020 to detect pandemic-related changes. RESULTS: During the first wave of the pandemic, 41.6% of PWE reported a negative impact on their mental health, while only a minority reported worsening of their seizure situation. Mental and physical health were significantly more negatively affected in women than men with epilepsy and in PWE without regular employment. Moreover, difficulties in ensuring the supply of sanitary products (25.8%) and antiseizure medications (ASMs; 19.9%) affected PWE during the first lockdown; no significant difference regarding these impacts between men and women or between people with and without employment was observed. The number of epilepsy-related admissions decreased significantly during the first wave. CONCLUSIONS: This analysis provides an overview of the general and medical care of epilepsy patients during the COVID-19 pandemic. PWE in our cohort frequently reported psychosocial distress during the first wave of the pandemic, with significant adverse effects on mental and physical health. Women and people without permanent jobs especially reported distress due to the pandemic. The COVID-19 pandemic has added to the mental health burden and barriers to accessing medication and medical services, as self-reported by patients and verified in population-based data on hospital admissions. TRIAL REGISTRATION: German Clinical Trials Register (DRKS), DRKS00022024. Registered October 2, 2020, http://www.drks.de/DRKS00022024.

14.
Strahlenther Onkol ; 198(12): 1105-1111, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36149437

RESUMO

PURPOSE: Does focal cavity radiotherapy after resection of brain metastasis "spare" whole-brain radiotherapy, which is associated with toxicity for patients, through the complete course of their disease without compromising long-term local control of the brain? METHODS: We retrospectively analyzed outcomes of patients who underwent adjuvant focal cavity radiotherapy between 2014 and 2021 at our center. RESULTS: A total of 83 patients with 86 resected brain metastases were analyzed. 64% had singular, 36% two to four brain metastases. In cases with multiple metastases, omitted lesions were treated with radiosurgery. Median follow-up was 7.3 months (range 0-71.2 months), 1­year overall survival rate was 57.8% (95% CI 44.9-68.8%). Radiotherapy was administered with a median biologically effective dose (α/ß 10) surrounding the planning target volume of 48 Gy (range 23.4-60 Gy). Estimated 1­year local control rate was 82.7% (95% CI 67.7-91.2%), estimated 1­year distant brain control rate was 55.7% (95% CI 40.5-68.4%), estimated 1­year leptomeningeal disease rate was 16.0% (95% CI 7.3-32.9%). Eleven distant brain recurrences could be salvaged with radiosurgery. In the further course of disease, 14 patients (17%) developed disseminated metastatic disease in the brain. Estimated 1­year free of whole-brain radiotherapy rate was 72.3% (95% CI 57.1-82.9%). All applied treatments led to an estimated 1­year neuro-control rate of 79.1% (95% CI 65.0-88.0%), estimated 1­year radionecrosis rate was 23% (95% CI 12.4-40.5%). CONCLUSION: In our single-center study, focal cavity radiotherapy was associated with high local control. In three out of four patients, whole-brain radiotherapy could be avoided in the complete course of disease, using radiosurgery as salvage approach without compromising neuro-control.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Humanos , Estudos Retrospectivos , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/secundário , Terapia de Salvação , Radioterapia Adjuvante , Irradiação Craniana
15.
Cancer Gene Ther ; 29(5): 484-493, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35145272

RESUMO

Aberrant somatic hypermutation (aSHM) can target proto-oncogenes and drive oncogenesis. In mantle cell lymphoma (MCL), CCND1 is targeted by aSHM in the non-nodal subtype (nnMCL), giving rise to exon1 encoded mutant proteins like E36K, Y44D, and C47S that contribute to lymphomagenesis by virtue of their increased protein stability and nuclear localization. However, the vast majority of somatic variants generated by aSHM are found in the first intron of CCND1 but their significance for mantle cell lymphomagenesis is unknown. We performed whole-genome and whole-transcriptome sequencing in 84 MCL patients to explore the contribution of non-coding somatic variants created by aSHM to lymphomagenesis. We show that non-coding variants are enriched in a MCL specific manner in transcription factor-binding sites, that non-coding variants are associated with increased CCND1 mRNA expression, and that coding variants in the first exon of CCND1 are more often synonymous or cause benign amino acid changes than in other types of lymphomas carrying a t(11;14) translocation. Therefore, the increased frequency of somatic variants due to aSHM might be a consequence of selection pressure manifested at the transcriptional level rather than being a mere mechanistic consequence of misguided activation-induced cytidine deaminase (AID) activity.


Assuntos
Ciclina D1 , Linfoma de Célula do Manto , Transformação Celular Neoplásica/genética , Ciclina D1/genética , Humanos , Linfoma de Célula do Manto/genética , Fenótipo , Translocação Genética
16.
Ultramicroscopy ; 233: 113440, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34920279

RESUMO

Ultimate resolution in scanning transmission electron microscopy (STEM) with state-of-the-art aberration correctors requires careful tuning of the experimental parameters. The optimum aperture semi-angle depends on the chosen high tension, the chromatic aberration and the energy width of the source as well as on potentially limiting intrinsic residual aberrations. In this paper we derive simple expressions and criteria for choosing the aperture semi-angle and for counterbalancing the intrinsic sixth-order three-lobe aberration of two-hexapole aberration correctors by means of the fourth-order three-lobe aberration. It is noteworthy that for such an optimally adjusted electron probe the so-called flat area of the Ronchigram is explicitly not maximized. The above considerations are validated by experiments with a CEOS ASCOR in a C-FEG-equipped JEOL NEOARM operated at 60 kV. Sub-Angstrom resolution is demonstrated for a Si[112] single crystal as well as for a single-layered MoS2 crystalline film. Lattice reflections of 73 pm for silicon and 93 pm for molybdenum disulfide are visible in the Fourier transform of the images, respectively. Moreover, single sulfur vacancies can be clearly identified in the MoS2.

17.
Strahlenther Onkol ; 197(12): 1124-1130, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34415358

RESUMO

PURPOSE: External-beam radiotherapy (EBRT) is the predominant method for localized brain radiotherapy (LBRT) after resection of brain metastases (BM). Intraoperative radiotherapy (IORT) with 50-kV x­rays is an alternative way to focally irradiate the resection cavity after BM surgery, with the option of shortening the overall treatment time and limiting normal tissue irradiation. METHODS: We retrospectively analyzed the outcomes of all patients who underwent neurosurgical resection of BM and 50-kV x­ray IORT between 2013 and 2020 at Augsburg University Medical Center. RESULTS: We identified 40 patients with 44 resected BM treated with 50-kV x­ray IORT. Median diameter of the resected metastases was 2.8 cm (range 1.5-5.9 cm). Median applied dose was 20 Gy. All patients received standardized follow-up (FU) including 3­monthly MRI of the brain. Mean FU was 14.4 months, with a median MRI FU for alive patients of 12.2 months. Median overall survival (OS) of all treated patients was 26.4 months (estimated 1­year OS 61.6%). The observed local control (LC) rate of the resection cavity was 88.6% (estimated 1­year LC 84.3%). Distant brain control (DC) was 47.5% (estimated 1­year DC 33.5%). Only 25% of all patients needed WBI in the further course of disease. The observed radionecrosis rate was 2.5%. CONCLUSION: IORT with 50-kV x­rays is a safe and appealing way to apply LBRT after neurosurgical resection of BM, with low toxicity and excellent LC. Close MRI FU is paramount to detect distant brain failure (DBF) early.


Assuntos
Neoplasias Encefálicas , Centros Médicos Acadêmicos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Humanos , Recidiva Local de Neoplasia/radioterapia , Radiografia , Estudos Retrospectivos , Raios X
18.
J Psychiatr Res ; 136: 543-551, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33221027

RESUMO

Anxiolytic drugs often have sedative effects that impair the ability to drive. Our double-blind, randomized crossover trial investigated the effect of Silexan, a non-sedating, anxiolytic herbal medicinal product, on driving performance in healthy volunteers. Part 1 aimed at demonstrating equivalence between 80 mg/d Silexan and placebo. Part 2 was performed to demonstrate superiority of 160 and 320 mg Silexan over 1 mg lorazepam and included a placebo arm for assay sensitivity. Driving performance was assessed in a validated, alcohol-calibrated simulator test. The primary outcome was the standard deviation of the lane position (SDLP). Secondary outcomes included driving errors and sleepiness. Fifty and 25 subjects were randomized in Parts 1 and 2, respectively. In Part 1, Silexan 80 mg was confirmed to be equivalent to placebo after single administration (equivalence range: δ = ±2 cm). The 95% confidence interval (CI) for the SDLP marginal mean value difference Silexan-placebo for single administration was -1.43; +1.38 and thus similar to the 95% CI of -1.45; +0.79 cm for 7 days' multiple dosing. In Part 2, 95% CIs for SDLP marginal mean value differences to lorazepam were -8.58; -5.42 cm for Silexan 160 mg and -8.65; -5.45 cm for 320 mg (p < 0.001). Confirmatory results were supported by secondary outcomes, where results for Silexan were comparable to placebo and more favorable than for lorazepam. The study demonstrates that single doses of up to 320 mg Silexan and multiple doses of 80 mg/d have no adverse effect on driving performance.


Assuntos
Condução de Veículo , Óleos Voláteis , Estudos Cross-Over , Método Duplo-Cego , Voluntários Saudáveis , Humanos , Lavandula , Óleos de Plantas , Desempenho Psicomotor
19.
Chem Sci ; 10(46): 10789-10801, 2019 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-31857889

RESUMO

Precision medicine has revolutionized the treatment of patients in EGFR driven non-small cell lung cancer (NSCLC). Targeted drugs show high response rates in genetically defined subsets of cancer patients and markedly increase their progression-free survival as compared to conventional chemotherapy. However, recurrent acquired drug resistance limits the success of targeted drugs in long-term treatment and requires the constant development of novel efficient inhibitors of drug resistant cancer subtypes. Herein, we present covalent inhibitors of the drug resistant gatekeeper mutant EGFR-L858R/T790M based on the pyrrolopyrimidine scaffold. Biochemical and cellular characterization, as well as kinase selectivity profiling and western blot analysis, substantiate our approach. Moreover, the developed compounds possess high activity against multi drug resistant EGFR-L858R/T790M/C797S in biochemical assays due to their highly reversible binding character, that was revealed by characterization of the binding kinetics. In addition, we present the first X-ray crystal structures of covalent inhibitors in complex with C797S-mutated EGFR which provide detailed insight into their binding mode.

20.
Diabetes Care ; 42(11): 2050-2056, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31488568

RESUMO

OBJECTIVE: To investigate temporal trends and contemporary use of insulin pump therapy and glucose monitoring in type 1 diabetes. RESEARCH DESIGN AND METHODS: In a population-based study, we analyzed the use of insulin pump therapy, continuous glucose monitoring (CGM), and self-monitoring of blood glucose (SMBG) from 1995 to 2017 in patients with type 1 diabetes identified from the Diabetes Prospective Follow-up (DPV) database in Germany and Austria. Patients were stratified by age, sex, migration background, and country. RESULTS: Among 96,547 patients with type 1 diabetes (median age 17.9 years, 53% males), the percentage using insulin pump therapy increased from 1% in 1995 to 53% in 2017, with the highest rates in the youngest patients (92% in preschoolers, 74% in children, 56% in adolescents aged <15 years, 46% in adolescents aged ≥15 years, 37% in adults). The percentage of patients using CGM increased from 3% in 2006 to 38% in 2017, with the highest rates in the youngest patients (58%, 52%, 45%, 33%, and 15% of respective age-groups). Daily SMBG frequencies increased from 1995 to 2016 and decreased afterward, most prominently in the youngest patients. Between 2015 and 2017, pump therapy was more frequently used in female versus male adolescents and adults (all P < 0.001), while no sex differences were observed for pump use in children <10 years (all P = 1.0) and for CGM use in all age-groups (all P = 1.0). CONCLUSIONS: Since 1995, insulin pump use has continuously increased, and insulin pump therapy is now standard in patients aged <15 years. CGM use sharply rose in recent years, particularly in young children.


Assuntos
Automonitorização da Glicemia/tendências , Diabetes Mellitus Tipo 1/terapia , Hipoglicemiantes/uso terapêutico , Sistemas de Infusão de Insulina/tendências , Insulinas/uso terapêutico , Adolescente , Adulto , Áustria , Glicemia/análise , Criança , Pré-Escolar , Bases de Dados Factuais , Diabetes Mellitus Tipo 1/sangue , Feminino , Seguimentos , Alemanha , Humanos , Estudos Longitudinais , Masculino , Estudos Prospectivos , Adulto Jovem
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