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1.
Genes Dev ; 32(19-20): 1332-1343, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30254107

RESUMO

Plants have evolved complex photoreceptor-controlled mechanisms to sense and respond to seasonal changes in day length. This ability allows plants to optimally time the transition from vegetative growth to flowering. UV-B is an important part intrinsic to sunlight; however, whether and how it affects photoperiodic flowering has remained elusive. Here, we report that, in the presence of UV-B, genetic mutation of REPRESSOR OF UV-B PHOTOMORPHOGENESIS 2 (RUP2) renders the facultative long day plant Arabidopsis thaliana a day-neutral plant and that this phenotype is dependent on the UV RESISTANCE LOCUS 8 (UVR8) UV-B photoreceptor. We provide evidence that the floral repression activity of RUP2 involves direct interaction with CONSTANS, repression of this key activator of flowering, and suppression of FLOWERING LOCUS T transcription. RUP2 therefore functions as an essential repressor of UVR8-mediated induction of flowering under noninductive short day conditions and thus provides a crucial mechanism of photoperiodic flowering control.


Assuntos
Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Proteínas Cromossômicas não Histona/metabolismo , Flores/crescimento & desenvolvimento , Fotoperíodo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Raios Ultravioleta
2.
Hum Mol Genet ; 32(13): 2192-2204, 2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37010102

RESUMO

Pathogenic heterozygous variants in SCN2A, which encodes the neuronal sodium channel NaV1.2, cause different types of epilepsy or intellectual disability (ID)/autism without seizures. Previous studies using mouse models or heterologous systems suggest that NaV1.2 channel gain-of-function typically causes epilepsy, whereas loss-of-function leads to ID/autism. How altered channel biophysics translate into patient neurons remains unknown. Here, we investigated iPSC-derived early-stage cortical neurons from ID patients harboring diverse pathogenic SCN2A variants [p.(Leu611Valfs*35); p.(Arg937Cys); p.(Trp1716*)] and compared them with neurons from an epileptic encephalopathy (EE) patient [p.(Glu1803Gly)] and controls. ID neurons consistently expressed lower NaV1.2 protein levels. In neurons with the frameshift variant, NaV1.2 mRNA and protein levels were reduced by ~ 50%, suggesting nonsense-mediated decay and haploinsufficiency. In other ID neurons, only protein levels were reduced implying NaV1.2 instability. Electrophysiological analysis revealed decreased sodium current density and impaired action potential (AP) firing in ID neurons, consistent with reduced NaV1.2 levels. In contrast, epilepsy neurons displayed no change in NaV1.2 levels or sodium current density, but impaired sodium channel inactivation. Single-cell transcriptomics identified dysregulation of distinct molecular pathways including inhibition of oxidative phosphorylation in neurons with SCN2A haploinsufficiency and activation of calcium signaling and neurotransmission in epilepsy neurons. Together, our patient iPSC-derived neurons reveal characteristic sodium channel dysfunction consistent with biophysical changes previously observed in heterologous systems. Additionally, our model links the channel dysfunction in ID to reduced NaV1.2 levels and uncovers impaired AP firing in early-stage neurons. The altered molecular pathways may reflect a homeostatic response to NaV1.2 dysfunction and can guide further investigations.


Assuntos
Epilepsia , Deficiência Intelectual , Epilepsia/genética , Deficiência Intelectual/genética , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Neurônios/metabolismo , Convulsões , Sódio/metabolismo , Canais de Sódio/genética , Humanos
3.
New Phytol ; 241(2): 747-763, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37964509

RESUMO

Land plants evolved multiple adaptations to restrict transpiration. However, the underlying molecular mechanisms are not sufficiently understood. We used an ozone-sensitivity forward genetics approach to identify Arabidopsis thaliana mutants impaired in gas exchange regulation. High water loss from detached leaves and impaired decrease of leaf conductance in response to multiple stomata-closing stimuli were identified in a mutant of MURUS1 (MUR1), an enzyme required for GDP-l-fucose biosynthesis. High water loss observed in mur1 was independent from stomatal movements and instead could be linked to metabolic defects. Plants defective in import of GDP-l-Fuc into the Golgi apparatus phenocopied the high water loss of mur1 mutants, linking this phenotype to Golgi-localized fucosylation events. However, impaired fucosylation of xyloglucan, N-linked glycans, and arabinogalactan proteins did not explain the aberrant water loss of mur1 mutants. Partial reversion of mur1 water loss phenotype by borate supplementation and high water loss observed in boron uptake mutants link mur1 gas exchange phenotypes to pleiotropic consequences of l-fucose and boron deficiency, which in turn affect mechanical and morphological properties of stomatal complexes and whole-plant physiology. Our work emphasizes the impact of fucose metabolism and boron uptake on plant-water relations.


Assuntos
Arabidopsis , Fucose , Fucose/metabolismo , Guanosina Difosfato Fucose/metabolismo , Boro/metabolismo , Arabidopsis/metabolismo , Polissacarídeos/metabolismo
4.
BMC Psychiatry ; 23(1): 38, 2023 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-36639626

RESUMO

BACKGROUND: Most studies agree that the Covid-19 pandemic and the subsequent lockdown had a negative impact on mental health. On the other hand, international studies have shown that psychiatric emergency departments (pED) experienced a decrease in presentations and admissions. METHODS: Retrospective chart review of all pED presentations and admissions during the first wave of Covid-19 pandemic in Germany (Covid-19 period: 3/2/20 to 05/24/20) in a psychiatric hospital in Berlin compared to 1 year earlier (pre-Covid-19 period). Descriptive statistics and logistic regression were performed. RESULTS: We observed no statistical significant changes in overall pED presentations and overall hospital admissions during the Covid-19 period compared to the pre-Covid-19 period (813 vs. 894, - 9.1%, p = 0.064 and (363 vs. 437, - 16.9%, p = 0.080 respectively). In the subgroup analysis, less patients with depressive disorders (p = 0.035) and with personality disorders (p = 0.002) presented to the pED, a larger number of presentations with schizophrenia was observed (p = 0.020). In the Covid-19 period, less patients with substance use disorder and paranoid schizophrenia were admitted to the hospital via the pED than in the pre-Covid-19 period (p = 0.035 and p = 0.006, respectively). Bed capacity was reduced in the Covid-19 period by - 32.8% (p <  0.001). Presentations in police custody were 13.7% (p = 0.029) higher during the Covid-19 compared to pre-Covid-19 period, with higher rates in female presentations (p = 0.008) and suicide attempts (p = 0.012) and less hospital admissions (p = 0.048). Logistic regression analyses revealed that positive predictors for pED presentation during Covid-19 period were police custody (p <  0.001), being redirected from another hospital (p <  0.001), suicide attempt (p = 0.038), suicidal thoughts (p = 0.004), presentation with paranoid schizophrenia (p = 0.001) and bipolar and manic disorders (p = 0.004), negative predictors were hospital admission (p <  0.001), depressive disorders (p = 0.021) and personality disorders (p <  0.001). CONCLUSIONS: A larger number of presentations in police custody during the Covid-19 period may represent untreated medical needs. This was seen predominantly in female patients, suggesting this subgroup might have suffered particularly under lockdown measures. Patients with paranoid schizophrenia were the only subgroup, which increased in absolute numbers, also suggesting a particular lockdown effect. Reduced bed capacity due to infection curbing measures is suggestive to have played an important role in augmenting the threshold for hospital admissions.


Assuntos
Transtorno Bipolar , COVID-19 , Humanos , Feminino , Estudos Retrospectivos , Berlim/epidemiologia , Pandemias , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Alemanha/epidemiologia , Serviço Hospitalar de Emergência
5.
Acta Neurochir (Wien) ; 165(9): 2381-2387, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37460666

RESUMO

INTRODUCTION: Acute subdural hematoma (aSDH) is one of the main causes of high mortality and morbidity in traumatic brain injury. Prognosis is poor due to the rapid volume shift and mass effect. Cerebral perfusion is likely affected in this condition. This study quantifies perfusion changes in aSDH using early ER polytrauma CT with perfusion imaging (CTP). METHODS: Data of 54 patients with traumatic aSDH were retrospectively collected. Glasgow Coma scale (GCS), perfusion parameters, therapeutic decisions and imaging data including hematoma thickness, midline shift, and hematoma localization were analyzed. The cortical perfusion parameters of each hemisphere, the area anterior to the hematoma (AAH), area below the hematoma (ABH), area posterior to the hematoma (PAH), and corresponding mirrored contralateral regions were determined. RESULTS: We found a significant difference in Tmax in affected and unaffected whole-hemisphere data (mean 4.0 s vs. 3.3 s, p < 0.05) and a significantly different mean for Tmax in ABH and for the corresponding mirrored area (mABH) (mean 3.8 s vs. 3.1 s, p < 0.05). No significant perfusion changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were found. CONCLUSION: There was a significant elevation of time to maximum (Tmax) values in the underlying cortical area of aSDH. Possible pathophysiological explanations, the influence on immediate surgical decision-making and further therapeutic consequences have to be evaluated.


Assuntos
Hematoma Subdural Agudo , Humanos , Hematoma Subdural Agudo/diagnóstico por imagem , Hematoma Subdural Agudo/cirurgia , Estudos Retrospectivos , Hematoma , Perfusão , Circulação Cerebrovascular
6.
Plant Cell Physiol ; 62(3): 502-514, 2021 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-33544865

RESUMO

Plants are constantly exposed to stressful environmental conditions. Plant stress reactions were mainly investigated for single stress factors. However, under natural conditions plants may be simultaneously exposed to different stresses. Responses to combined stresses cannot be predicted from the reactions to the single stresses. Flavonoids accumulate in Arabidopsis thaliana during exposure to UV-A, UV-B or cold, but the interactions of these factors on flavonoid biosynthesis were unknown. We therefore investigated the interaction of UV radiation and cold in regulating the expression of well-characterized stress-regulated genes, and on transcripts and metabolites of the flavonoid biosynthetic pathway in 52 natural Arabidopsis accessions that differ widely in their freezing tolerance. The data revealed interactions of cold and UV on the regulation of stress-related and flavonoid biosynthesis genes, and on flavonoid composition. In many cases, plant reactions to a combination of cold and UV were unique under combined stress and not predictable from the responses to the single stresses. Strikingly, all correlations between expression levels of flavonoid biosynthesis genes and flavonol levels were abolished by UV-B exposure. Similarly, correlations between transcript levels of flavonoid biosynthesis genes or flavonoid contents, and freezing tolerance were lost in the presence of UV radiation, while correlations with the expression levels of cold-regulated genes largely persisted. This may indicate different molecular cold acclimation responses in the presence or absence of UV radiation.


Assuntos
Arabidopsis/genética , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Variação Genética/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Temperatura Baixa , Congelamento , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Estresse Fisiológico , Raios Ultravioleta
7.
Oecologia ; 197(4): 903-919, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33880635

RESUMO

Climate change is increasing the frequency and intensity of warming and drought periods around the globe, currently representing a threat to many plant species. Understanding the resistance and resilience of plants to climate change is, therefore, urgently needed. As date palm (Phoenix dactylifera) evolved adaptation mechanisms to a xeric environment and can tolerate large diurnal and seasonal temperature fluctuations, we studied the protein expression changes in leaves, volatile organic compound emissions, and photosynthesis in response to variable growth temperatures and soil water deprivation. Plants were grown under controlled environmental conditions of simulated Saudi Arabian summer and winter climates challenged with drought stress. We show that date palm is able to counteract the harsh conditions of the Arabian Peninsula by adjusting the abundances of proteins related to the photosynthetic machinery, abiotic stress and secondary metabolism. Under summer climate and water deprivation, these adjustments included efficient protein expression response mediated by heat shock proteins and the antioxidant system to counteract reactive oxygen species formation. Proteins related to secondary metabolism were downregulated, except for the P. dactylifera isoprene synthase (PdIspS), which was strongly upregulated in response to summer climate and drought. This study reports, for the first time, the identification and functional characterization of the gene encoding for PdIspS, allowing future analysis of isoprene functions in date palm under extreme environments. Overall, the current study shows that reprogramming of the leaf protein profiles confers the date palm heat- and drought tolerance. We conclude that the protein plasticity of date palm is an important mechanism of molecular adaptation to environmental fluctuations.


Assuntos
Phoeniceae , Secas , Fotossíntese , Folhas de Planta , Arábia Saudita , Estresse Fisiológico
8.
Ann Oncol ; 31(1): 137-143, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31912788

RESUMO

BACKGROUND: Convolutional neural networks (CNNs) efficiently differentiate skin lesions by image analysis. Studies comparing a market-approved CNN in a broad range of diagnoses to dermatologists working under less artificial conditions are lacking. MATERIALS AND METHODS: One hundred cases of pigmented/non-pigmented skin cancers and benign lesions were used for a two-level reader study in 96 dermatologists (level I: dermoscopy only; level II: clinical close-up images, dermoscopy, and textual information). Additionally, dermoscopic images were classified by a CNN approved for the European market as a medical device (Moleanalyzer Pro, FotoFinder Systems, Bad Birnbach, Germany). Primary endpoints were the sensitivity and specificity of the CNN's dichotomous classification in comparison with the dermatologists' management decisions. Secondary endpoints included the dermatologists' diagnostic decisions, their performance according to their level of experience, and the CNN's area under the curve (AUC) of receiver operating characteristics (ROC). RESULTS: The CNN revealed a sensitivity, specificity, and ROC AUC with corresponding 95% confidence intervals (CI) of 95.0% (95% CI 83.5% to 98.6%), 76.7% (95% CI 64.6% to 85.6%), and 0.918 (95% CI 0.866-0.970), respectively. In level I, the dermatologists' management decisions showed a mean sensitivity and specificity of 89.0% (95% CI 87.4% to 90.6%) and 80.7% (95% CI 78.8% to 82.6%). With level II information, the sensitivity significantly improved to 94.1% (95% CI 93.1% to 95.1%; P < 0.001), while the specificity remained unchanged at 80.4% (95% CI 78.4% to 82.4%; P = 0.97). When fixing the CNN's specificity at the mean specificity of the dermatologists' management decision in level II (80.4%), the CNN's sensitivity was almost equal to that of human raters, at 95% (95% CI 83.5% to 98.6%) versus 94.1% (95% CI 93.1% to 95.1%); P = 0.1. In contrast, dermatologists were outperformed by the CNN in their level I management decisions and level I and II diagnostic decisions. More experienced dermatologists frequently surpassed the CNN's performance. CONCLUSIONS: Under less artificial conditions and in a broader spectrum of diagnoses, the CNN and most dermatologists performed on the same level. Dermatologists are trained to integrate information from a range of sources rendering comparative studies that are solely based on one single case image inadequate.


Assuntos
Melanoma , Neoplasias Cutâneas , Dermatologistas , Dermoscopia , Alemanha , Humanos , Masculino , Melanoma/diagnóstico por imagem , Redes Neurais de Computação
9.
Glob Chang Biol ; 26(3): 1908-1925, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31957145

RESUMO

Warming occurs in the Arctic twice as fast as the global average, which in turn leads to a large enhancement in terpenoid emissions from vegetation. Volatile terpenoids are the main class of biogenic volatile organic compounds (VOCs) that play crucial roles in atmospheric chemistry and climate. However, the biochemical mechanisms behind the temperature-dependent increase in VOC emissions from subarctic ecosystems are largely unexplored. Using 13 CO2 -labeling, we studied the origin of VOCs and the carbon (C) allocation under global warming in the soil-plant-atmosphere system of contrasting subarctic heath tundra vegetation communities characterized by dwarf shrubs of the genera Salix or Betula. The projected temperature rise of the subarctic summer by 5°C was realistically simulated in sophisticated climate chambers. VOC emissions strongly depended on the plant species composition of the heath tundra. Warming caused increased VOC emissions and significant changes in the pattern of volatiles toward more reactive hydrocarbons. The 13 C was incorporated to varying degrees in different monoterpene and sesquiterpene isomers. We found that de novo monoterpene biosynthesis contributed to 40%-44% (Salix) and 60%-68% (Betula) of total monoterpene emissions under the current climate, and that warming increased the contribution to 50%-58% (Salix) and 87%-95% (Betula). Analyses of above- and belowground 12/13 C showed shifts of C allocation in the plant-soil systems and negative effects of warming on C sequestration by lowering net ecosystem exchange of CO2 and increasing C loss as VOCs. This comprehensive analysis provides the scientific basis for mechanistically understanding the processes controlling terpenoid emissions, required for modeling VOC emissions from terrestrial ecosystems and predicting the future chemistry of the arctic atmosphere. By changing the chemical composition and loads of VOCs into the atmosphere, the current data indicate that global warming in the Arctic may have implications for regional and global climate and for the delicate tundra ecosystems.


Assuntos
Aquecimento Global , Compostos Orgânicos Voláteis , Regiões Árticas , Ecossistema , Tundra
10.
J Eur Acad Dermatol Venereol ; 34(6): 1355-1361, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31856342

RESUMO

BACKGROUND: Deep learning convolutional neural networks (CNN) may assist physicians in the diagnosis of melanoma. The capacity of a CNN to differentiate melanomas from combined naevi, the latter representing well-known melanoma simulators, has not been investigated. OBJECTIVE: To assess the diagnostic performance of a CNN when used to differentiate melanomas from combined naevi in comparison with dermatologists. METHODS: In this study, a CNN with regulatory approval for the European market (Moleanalyzer-Pro, FotoFinder Systems GmbH, Bad Birnbach, Germany) was used. We attained a dichotomous classification (benign, malignant) in dermoscopic images of 36 combined naevi and 36 melanomas with a mean Breslow thickness of 1.3 mm. Primary outcome measures were the CNN's sensitivity, specificity and the diagnostic odds ratio (DOR) in comparison with 11 dermatologists with different levels of experience. RESULTS: The CNN revealed a sensitivity, specificity and DOR of 97.1% (95% CI [82.7-99.6]), 78.8% (95% CI [62.8-89.1.3]) and 34 (95% CI [4.8-239]), respectively. Dermatologists showed a lower mean sensitivity, specificity and DOR of 90.6% (95% CI [84.1-94.7]; P = 0.092), 71.0% (95% CI [62.6-78.1]; P = 0.256) and 24 (95% CI [11.6-48.4]; P = 0.1114). Under the assumption that dermatologists use the CNN to verify their (initial) melanoma diagnosis, dermatologists achieve an increased specificity of 90.3% (95% CI [79.8-95.6]) at an almost unchanged sensitivity. The largest benefit was observed in 'beginners', who performed worst without CNN verification (DOR = 12) but best with CNN verification (DOR = 98). CONCLUSION: The tested CNN more accurately classified combined naevi and melanomas in comparison with trained dermatologists. Their diagnostic performance could be improved if the CNN was used to confirm/overrule an initial melanoma diagnosis. Application of a CNN may therefore be of benefit to clinicians.


Assuntos
Aprendizado Profundo , Dermatologistas , Diagnóstico por Computador/métodos , Melanoma/diagnóstico por imagem , Nevo Pigmentado/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Adulto , Idoso , Competência Clínica , Dermoscopia , Feminino , Humanos , Masculino , Melanócitos/patologia , Melanoma/patologia , Pessoa de Meia-Idade , Nevo Pigmentado/patologia , Sensibilidade e Especificidade , Neoplasias Cutâneas/patologia , Adulto Jovem
11.
Hautarzt ; 71(2): 101-108, 2020 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-31965207

RESUMO

BACKGROUND: Since the establishment of dermoscopy as a routine examination procedure in dermatology, the spectrum of noninvasive, optical devices has further expanded. In difficult-to-diagnose clinical cases, these systems may support dermatologists to arrive at a correct diagnosis without the need for a surgical biopsy. OBJECTIVE: To give an overview about technical background, indications and diagnostic performance regarding four new optical procedures: reflectance confocal microscopy, in vivo multiphoton tomography, dermatofluoroscopy, and systems based on image analysis by artificial intelligence (AI). MATERIALS AND METHODS: This article is based on a selective review of the literature, as well as the authors' personal experience from clinical studies relevant for market approval of the devices. RESULTS: In contrast to standard histopathological slides with vertical cross sections, reflectance confocal microscopy and in vivo multiphoton tomography allow for "optical biopsies" with horizontal cross sections. Dermatofluoroscopy and AI-based image analyzers provide a numerical score, which helps to correctly classify a skin lesion. The presented new optical procedures may be applied for the diagnosis of skin cancer as well as inflammatory skin diseases. CONCLUSION: The presented optical procedures provide valuable additional information that supports dermatologists in making the correct diagnosis. However, a surgical biopsy followed by dermatohistopathological examination remains the diagnostic gold standard in dermatology.


Assuntos
Dermatologia , Dermatopatias , Neoplasias Cutâneas , Dermoscopia , Humanos , Microscopia Confocal , Pele , Dermatopatias/diagnóstico , Neoplasias Cutâneas/diagnóstico
12.
Atmos Sci Lett ; 20(3): e888, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31191173

RESUMO

Low-level jets (LLJs) are relatively fast-moving streams of air that form in the lower troposphere and are a common phenomenon across the Great Plains (GP) of the United States. LLJs play an important role in moisture transport and the development of nocturnal convection in the spring and summer. Alterations to surface moisture and energy fluxes can influence the planetary boundary layer (PBL) development and thus LLJs. One important anthropogenic process that has been shown to affect the surface energy budget is irrigation. In this study, we investigate the effects of irrigation on LLJ development across the GP by incorporating a dynamic and realistic irrigation scheme into the Weather Research and Forecasting (WRF) model. WRF simulations were conducted with and without the irrigation scheme for the exceptionally dry summer of 2012 over the GP. The results show irrigation-introduced changes to LLJ features both over and downstream of the most heavily irrigated regions in the GP. There were statistically significant increases to LLJ speeds in the simulation with the irrigation parameterization. Decreases to the mean jet core height on the order of 50 m during the overnight hours were also simulated when irrigation was on. The overall frequency of jet occurrences increased over the irrigated regions by 5-10%; however, these differences were not statistically significant. These changes were weaker than those reported in earlier studies based on simple representations of irrigation that unrealistically saturate the soil columns over large areas over a long period of time, which highlights the importance and necessity to represent human activity more accurately in modeling studies.

13.
Photochem Photobiol Sci ; 17(1): 27-34, 2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29143029

RESUMO

The products from the 193 nm irradiation of triphenylsulfonium nonaflate (TPS) embedded in a poly(methyl methacrylate) (PMMA) film have been characterized. The analysis of the photoproduct formation was performed using chromatographic techniques including HPLC, GPC and GC-MS as well as UV-vis and NMR spectroscopic methods. Two previously unreported TPS photoproducts, triphenylene and dibenzothiophene, were detected; additionally, GPC and DOSY-NMR spectroscopic analyses after irradiation suggested that TPS fragments had been incorporated into the polymer film. The irradiation of acetonitrile solutions containing 10% w/v PMMA and 1% w/v TPS in a 1 cm-path-length cuvette showed only a trace amount of triphenylene or dibenzothiophene, indicating that topochemical factors were important for the formation of these molecules. The accumulated evidence indicates that both products were formed by in-cage, secondary photochemical reactions: 2-(phenylthio)biphenyl to triphenylene, and diphenylsulfide to dibenzothiophene.

15.
BMC Plant Biol ; 17(1): 120, 2017 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-28693422

RESUMO

BACKGROUND: Elevated temperature and reduced water availability are frequently linked abiotic stresses that may provoke distinct as well as interacting molecular responses. Based on non-targeted metabolomic and transcriptomic measurements from Arabidopsis rosettes, this study aims at a systematic elucidation of relevant components in different drought and heat scenarios as well as relationships between molecular players of stress response. RESULTS: In combined drought-heat stress, the majority of single stress responses are maintained. However, interaction effects between drought and heat can be discovered as well; these relate to protein folding, flavonoid biosynthesis and growth inhibition, which are enhanced, reduced or specifically induced in combined stress, respectively. Heat stress experiments with and without supplementation of air humidity for maintenance of vapor pressure deficit suggest that decreased relative air humidity due to elevated temperature is an important component of heat stress, specifically being responsible for hormone-related responses to water deprivation. Remarkably, this "dry air effect" is the primary trigger of the metabolomic response to heat. In contrast, the transcriptomic response has a substantial temperature component exceeding the dry air component and including up-regulation of many transcription factors and protein folding-related genes. Data level integration independent of prior knowledge on pathways and condition labels reveals shared drought and heat responses between transcriptome and metabolome, biomarker candidates and co-regulation between genes and metabolic compounds, suggesting novel players in abiotic stress response pathways. CONCLUSIONS: Drought and heat stress interact both at transcript and at metabolite response level. A comprehensive, non-targeted view of this interaction as well as non-interacting processes is important to be taken into account when improving tolerance to abiotic stresses in breeding programs. Transcriptome and metabolome may respond with different extent to individual stress components. Their contrasting behavior in response to temperature stress highlights that the protein folding machinery effectively shields the metabolism from stress. Disentangling the complex relationships between transcriptome and metabolome in response to stress is an enormous challenge. As demonstrated by case studies with supporting evidence from additional data, the large dataset provided in this study may assist in determining linked genetic and metabolic features as candidates for future mechanistic analyses.


Assuntos
Adaptação Fisiológica , Regulação da Expressão Gênica de Plantas , Metaboloma , Estresse Fisiológico , Transcriptoma , Aquaporinas/genética , Aquaporinas/metabolismo , Arabidopsis , Secas , Temperatura Alta , Umidade , Sacarose/metabolismo
16.
Br J Dermatol ; 176(1): 216-219, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27038231

RESUMO

The immune system is extremely important in the development and progression of Merkel cell carcinoma (MCC). Immune checkpoint blockade has recently been shown to enable efficacious treatment of a variety of tumours. We report the use of an anti-programmed death receptor 1 (PD-1) antibody for treatment of a patient with metastatic MCC. An 80-year-old patient with metastatic MCC received off-label treatment with the anti-PD-1 antibody pembrolizumab after the disease had progressed during therapy with oral etoposide. A positron emission tomography (PET) computed tomography scan performed after three cycles of pembrolizumab revealed responses to therapy with reduced size of the adrenal gland metastases and less PET activity in the adrenal gland and lymph node metastases. Treatment was resumed owing to disease progression after a treatment-free interval of > 4 months. During subsequent months of treatment, the size of the metastases stabilized and uptake of nuclide by all tumour sites once again decreased. These results reveal the potential efficacy of an anti-PD-1 antibody for treatment of metastatic MCC. Thus, they contribute to currently limited data on the use of anti-PD-1 antibodies for the treatment of MCC. Moreover, this is the first report of successful resumption of treatment of metastatic MCC with an anti-PD-1 antibody. Results from ongoing trials will contribute to determination of the relevance of PD-1 blockade in metastatic MCC.


Assuntos
Neoplasias das Glândulas Suprarrenais/secundário , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma de Célula de Merkel/tratamento farmacológico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Neoplasias Cutâneas/tratamento farmacológico , Idoso de 80 Anos ou mais , Carcinoma de Célula de Merkel/secundário , Humanos , Metástase Linfática , Masculino , Tomografia por Emissão de Pósitrons
17.
J Dairy Sci ; 100(6): 4976-4986, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28342615

RESUMO

With the onset of lactation, dairy cows with a body condition score >3.5 are sensitive to oxidative stress and metabolic disorders. Adipose tissue (AT) can adapt to varying metabolic demands and energy requirements by the plasticity of its size during lactation. In AT, angiogenesis is necessary to guarantee sufficient oxygen and nutrient supply for adipocytes. Cellular energy metabolism is reflected mainly by mitochondria, which can be quantified by the mitochondrial DNA copy number per cell. In the present study, we aimed to investigate the effect of overconditioning on angiogenesis and mitochondrial biogenesis in AT of nonlactating cows, irrespective of the physiological influences of lactation and pregnancy. Eight nonpregnant, nonlactating cows received a ration of increasing energy density for 15 wk, during which body weight and body condition increased substantially. Subcutaneous AT was biopsied every 8 wk, and blood was sampled monthly. The blood concentrations of indicators of oxidative stress increased continuously throughout the experimental period, possibly damaging mitochondrial DNA. Concomitantly, HIF-1α, a major marker for hypoxia, increased until wk 8, indicating insufficient angiogenesis in the rapidly expanding AT. Based on the observation that the number of apoptotic cells decreased with increasing hypoxia, the increasing mitochondrial DNA copy numbers might compensate for the hypoxia, reinforcing the production of oxidative stressors. Key transcription factors of mitochondrial biogenesis were largely unaffected. Thus, increased oxidative stress does not impair mitochondrial DNA.


Assuntos
Adaptação Fisiológica , Tecido Adiposo/fisiologia , DNA Mitocondrial , Metabolismo Energético , Neovascularização Fisiológica , Biogênese de Organelas , Estresse Oxidativo , Tecido Adiposo/irrigação sanguínea , Animais , Biomarcadores/sangue , Bovinos , Hipóxia Celular , Ingestão de Energia , Feminino , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lactação/fisiologia , Gravidez , Gordura Subcutânea
18.
Radiologe ; 57(10): 814-821, 2017 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-28730266

RESUMO

CLINICAL ISSUE: The incidence of malignant melanoma is continuously increasing. The prognosis of metastatic disease is still limited. STANDARD TREATMENT: Until a few years ago palliative chemotherapy with a limited response rate was the standard treatment for metastatic melanoma. TREATMENT INNOVATIONS: Immunotherapy and targeted therapy provide new treatment options. Immune checkpoint inhibitors have significantly improved the prognosis. DIAGNOSTIC WORK-UP: Regional lymph node sonography, computed tomography (CT) of the neck, chest and abdomen and brain magnetic resonance imaging (MRI) are routinely used. As an alternative to CT scans 18 F fluorodeoxyglucose positron emission tomography (FDG-PET) may be used. PERFORMANCE AND ACHIEVEMENTS: Immunotherapy provides the chance of long-term disease control in metastatic melanoma. Ipilimumab may provide long-term tumor control in approximately 20% of patients. Median overall survival of approximately 2 years is achieved during therapy with anti-programmed cell death (PD) 1 antibodies. For combined therapy of ipilimumab and nivolumab a response rate of almost 60% is achieved and 2­year survival is also approximately 60%. The range of immune-mediated side effects demands particular consideration. For response evaluation immune-related response criteria were defined. Furthermore, immunotherapeutic approaches, such as talimogene laherparepvec (T-VEC), which is a modified herpes virus can be used for intralesional injection. PRACTICAL RECOMMENDATIONS: An individual definition of the appropriate therapy for each patient is of particular importance. In the context of modern therapy regimens close patient monitoring is crucial.


Assuntos
Melanoma/terapia , Neoplasias Cutâneas/terapia , Humanos , Imunoterapia , Melanoma/diagnóstico por imagem , Nivolumabe , Tomografia por Emissão de Pósitrons , Neoplasias Cutâneas/diagnóstico por imagem
19.
Hautarzt ; 68(5): 393-395, 2017 May.
Artigo em Alemão | MEDLINE | ID: mdl-27872944

RESUMO

Multiple eccrine hidrocystomas are benign cystic skin lesions which originate from the sweat gland ducts and typically affect women's midfacial area. Sweating may lead to an increase in size of the translucent papules. In some cases hidrocystomas are associated with other diseases such as Parkinson's disease. Treatment options include laser, topical and systemic anticholinergic drugs (glycopyrrolate, clonidine, atropine, and oxybutynin), whereby therapeutic success is limited in most cases.


Assuntos
Hidrocistoma/patologia , Hidrocistoma/terapia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Primárias Múltiplas/terapia , Neoplasias das Glândulas Sudoríparas/patologia , Neoplasias das Glândulas Sudoríparas/terapia , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade
20.
Hautarzt ; 68(11): 890-895, 2017 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-28905116

RESUMO

BACKGROUND: Teledermoscopy is a promising modern technique to complement or to substitute dermatologic examination. OBJECTIVE: In this pilot study, we compared the outcomes of teledermoscopic consultations with clinical examinations and histologic results. METHODS: Conventional and dermatoscopic photos of single lesions were taken in 26 patients using a mobile phone and an attached handyscope optical system. Five resident physicians performed a clinical examination including dermoscopy while the teledermatologic and teledermoscopic photos were assessed by an experienced dermatologist. Examination results were compared regarding diagnosis, differential diagnoses, recommended further management, as well as subjective and objective accuracy of diagnosis. In addition, 23% of the lesions were excised and histologically examined. RESULTS: The most frequent diagnosis was "nevus cell nevus", followed by "subungual hematoma" and "basal cell carcinoma". The concordance of diagnoses was 92.3%; the concordance of recommended further management was 76.9%. Of the 6 histologically proven diagnoses, 66.7% were given the same diagnosis by teledermatoscopy and conventional clinical assessment. Concerning accuracy of diagnosis, teledermoscopy showed no disadvantage. CONCLUSIONS: Teledermatologic photos of single lesions combined with teledermatoscopic photos can be reliably and safely assessed. Especially when access to dermatologic examination is difficult, mobile teledermoscopy is a good and reliable alternative.


Assuntos
Dermoscopia/instrumentação , Hematoma/diagnóstico , Melanoma/diagnóstico , Nevo Pigmentado/diagnóstico , Neoplasias Cutâneas/diagnóstico , Smartphone , Telemedicina/instrumentação , Desenho de Equipamento , Alemanha , Humanos , Melanoma/patologia , Nevo Pigmentado/patologia , Projetos Piloto , Garantia da Qualidade dos Cuidados de Saúde , Reprodutibilidade dos Testes , Pele/patologia , Neoplasias Cutâneas/patologia
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