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1.
Phys Med ; 122: 103376, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38772061

RESUMO

PURPOSE: To assess the impact of rigid and deformable image registration methods (RIR, DIR) on the outcome of a hypoxia-based dose painting strategy. MATERIALS AND METHODS: Thirty head and neck cancer patients were imaged with [18F]FMISO-PET/CT before radiotherapy. [18F]FMISO-PET/CT images were registered to the planning-CT by RIR or DIR. The [18F]FMISO uptake was converted into oxygen partial pressure (pO2) maps. Hypoxic Target Volumes were contoured on pO2 maps for the deformed (HTVdef) and non-deformed (HTV) cases. A dose escalation strategy by contours, aiming at 95 % tumour control probability (TCP), was applied. HTVs were characterised based on geometry-related metrics, the underlying pO2 distribution, and the dose boost level. A dosimetric and radiobiological evaluation of selected treatment plans made considering RIR and DIR was performed. Moreover, the TCP of the RIR dose distribution was evaluated when considering the deformed [18F]FMISO-PET image as an indicator of the actual target radiosensitivity to determine the potential impact of an unalignment. RESULTS: Statistically significant differences were found between HTV and HTVdef for volume-based metrics and underlying pO2 distribution. Eight out of nine treatment plans for HTV and HTVdef showed differences on the level 10 %/3 mm on a gamma analysis. The TCP difference, however, between RIR and the case when the RIR dose distribution was used with the deformed radiosensitivity map was below 2 pp. CONCLUSIONS: Although the choice of the CTplan-to-PET registration method pre-treatment impacts the HTV localisation and morphology and the corresponding dose distribution, it negligibly affects the TCP in the proposed dose escalation strategy by contours.


Assuntos
Neoplasias de Cabeça e Pescoço , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Humanos , Neoplasias de Cabeça e Pescoço/radioterapia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Planejamento da Radioterapia Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos , Misonidazol/análogos & derivados , Doses de Radiação
2.
Tech Coloproctol ; 26(6): 479-487, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35305182

RESUMO

BACKGROUND: The aim of this study was to evaluate the safety and efficacy of radiofrequency ablation (RFA) for treating third degree haemorrhoids, with a follow-up over 2 years. METHODS: We conducted a prospective, two-centre study to assess RFA of third-degree haemorrhoids in an outpatient setting. Treatment was performed under local anaesthesia, optionally in combination with sedation. The primary endpoint was analysis of a proctological symptom score ([PSS] bleeding, itching, pain, soiling) and proctological examination to detect recurrence at 1, 6, 12 and 24 months after surgery. The secondary endpoints were postoperative complications, incidence of postoperative pain, including administration of analgesics and time to return to daily routine. RESULTS: Ninety-eight patients were included in the study. The mean age of the patients was 49.1 ± 10.9 (mean ± SD). 83 patients (84.7%) were male and 15 patients (15.3%) were female. The follow-up involved 100% (1 month), 95% (6 months), 86% (12 months) and 74% after 24 months. The individual symptom scores and overall PSS score decreased significantly in comparison to the initial score at each time point assessed. Prolapsed haemorrhoids decreased in comparison to the initial situation (100%) to 7.2% (1 month), 3.5% (6 months), 13.1% (12 months) and 13.7% (after 24 months). Thirteen patients (12.7%) required repeat haemorrhoid therapy during the 2-year follow-up period. The mean maximum pain score after the procedure was 2.5 ± 2.7 (determined with the visual analogue scale), while 33 (33.7%) patients reported having no pain. 59 (60.2%) patients did not take analgesics after the procedure. Eleven patients (11.2%) experienced minor complications (bleeding, fever, cramps, diarrhoea, anal venous thrombosis) but did not require additional treatment. Eight cases (8.2%) of major complications (infection, bleeding, severe pain) required treatment with antibiotics, a second intervention, analgesics or hospitalization. CONCLUSIONS: RFA is safe and effective for treatment of third-degree haemorrhoids. The main advantages of this new method are its use on an outpatient basis under local anaesthesia, a very low level of postoperative pain and significant control of haemorrhoid symptoms over 2 years.


Assuntos
Ablação por Cateter , Hemorroidas , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Feminino , Hemorroidas/complicações , Hemorroidas/cirurgia , Humanos , Masculino , Dor Pós-Operatória/epidemiologia , Dor Pós-Operatória/etiologia , Estudos Prospectivos , Recidiva , Resultado do Tratamento
3.
Clin Transl Radiat Oncol ; 34: 51-56, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35345866

RESUMO

Purpose: To establish stable in vitro growth of keratinocytes from very small biopsy specimens and successfully apply new test systems to determine their radiosensitivity. Materials and Methods: Oral mucosa biopsies (diameter: 1.7 mm) from 15 subjects were immobilized with custom-made cups onto culture plates. Outgrowing cells were tested for cytokeratin 5/14 and Ki67, expanded, radiated at different doses, and seeded onto circumscribed areas before being allowed to spread centrifugally. In this newly developed spreading assay, cell-covered areas were measured by image analysis. For statistical analysis, a linear mixed regression model was used; additionally, results were correlated to the radiation dose applied. Colony forming efficiency (CFE) was used to validate the results. DNA damage repair was analysed by gammaH2AX and 53BP1 foci quantification using immunofluorescence microscopy 24 h and 96 h after irradiation. Results: Stable keratinocyte growth continued for up to 7 weeks in 14 biopsies. Cells spread reliably from an initial 16.6 mm2 up to a median of 119.2 mm2 (range: 54.4-290). Radiated cells spread to only 100.7 mm2 (2 Gy; range: 55.3-266.7); 73.2 mm2 (4 Gy; 15-240.4); 47 mm2 (6 Gy; 2-111.9), and 22.7 mm2 (8 Gy; 0-80). Similarly, CFE decreased from 0.223 (0 Gy) to 0.0028 (8 Gy). Using an individual donor as a random factor, cell spread correlated with CFE, where radiation dose was the main driver (decrease by 0.50, adjusted for area). Upon irradiation with 6 Gy, radiation-induced DNA damage was increased after 24 h in all samples, and even after 96 h in 5 out of 7 samples, as detected by a higher number of gammaH2AX/53BP1 foci in irradiated cells (mean 3.7 for 24 h; mean 0.6 for 96 h). Conclusion: In vitro propagation of keratinocytes derived from a small biopsy is feasible. Radiation impairs cellular migration and proliferation, and the newly described spreading assay allows ranking for cellular radioresistance. The keratinocyte model also supports classical functional assays such as clonogenic survival and DNA double strand repair. The clinical relevance awaits upcoming investigations.

4.
Radiother Oncol ; 167: 233-238, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34999135

RESUMO

BACKGROUND AND PURPOSE: Prognosis after chemoradiotherapy (CRT) for anal squamous cell carcinoma (ASCC) shows marked differences among patients according to TNM subgroups, however individualized risk assessment tools to better stratify patients for treatment (de-) escalation or intensified follow-up are lacking in ASCC. MATERIALS AND METHODS: Patients' data from eight sites of the German Cancer Consortium - Radiation Oncology Group (DKTK-ROG), comprising a total of 605 patients with ASCC, treated with standard definitive CRT with 5-FU/Mitomycin C or Capecitabine/Mitomycin C between 2004-2018, were used to evaluate prognostic factors based on Cox regression models for disease-free survival (DFS). Evaluated variables included age, gender, Karnofsky performance score (KPS), HIV-status, T-category, lymph node status and laboratory parameters. Multivariate cox models were separately constructed for the whole cohort and the subset of patients with early-stage (cT1-2 N0M0) tumors. RESULTS: After a median follow-up of 46 months, 3-year DFS for patients with early-stage ASCC was 84.9%, and 67.1% for patients with locally-advanced disease (HR 2.4, p < 0.001). T-category (HR vs. T1: T2 2.02; T3 2.11; T4 3.03), N-category (HR versus N0: 1.8 for N1-3), age (HR 1.02 per year), and KPS (HR 0.8 per step) were significant predictors for DFS in multivariate analysis in the entire cohort. The model performed with a C-index of 0.68. In cT1-2N0 patients, T-category (HR 2.14), HIV status (HR 2.57), age (1.026 per year), KPS (HR 0.7 per step) and elevated platelets (HR 1.3 per 100/nl) were associated with worse DFS (C-index of 0.7). CONCLUSION: Classical clinicopathologic parameters like T-category, N-category, age and KPS remain to be significant prognostic factors for DFS in patients treated with contemporary CRT for ASCC. HIV and platelets were significantly associated with worse DFS in patients with early stage ASCC.


Assuntos
Neoplasias do Ânus , Carcinoma de Células Escamosas , Quimiorradioterapia , Neoplasias do Ânus/terapia , Carcinoma de Células Escamosas/terapia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/etiologia , Humanos , Mitomicina , Prognóstico , Estudos Retrospectivos
5.
Pneumologie ; 75(4): 261-267, 2021 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-33873221

RESUMO

AIM: With the emergence of a new virus and the associated pandemic, the ICU started to see a brand new kind of patient with severe ARD. As with any disease, sometimes the discontinuation of mechanical ventilation for any reason can be difficult. As a center specializing in weaning patients after prolonged mechanical ventilation, we wanted to compare our results with weaning patients who had prolonged mechanical ventilation for other reasons than those of patients who had prolonged mechanical ventilation due to SARS-CoV-2 infection. METHODS: We obtained our data from WeanNet register, the weaning register of the German Institute for Lung Research (ILF). In our analysis, we included only patient data from January until July 2020, which was recorded in our in-house study files. RESULTS: Our analysis included data on 28 patients; 11 were treated with prolonged mechanical ventilation due to SARS-CoV-2 pneumonia, 17 had no SARS-CoV-2 infection. 81.2 % of SARS-CoV-2 patients were successfully weaned from invasive ventilator therapy compared to 76.4 % of patients without SARS-CoV-2. Mortality in the SARS-CoV-2 group was 18.2 % compared to 11.8 % in the other group. Patients with SARS-CoV-2 infections were predominantly males with preexisting cardiovascular disease or a history of nicotine abuse. ARDS was the most common cause of respiratory failure which led to primary intubation. CONCLUSION: Even though we were only able to analyze a small number of patient histories due to the novelty of the disease, we were able to show that patients with prolonged mechanical ventilation after SARS-CoV-2 infection can be equally successfully weaned compared to patients with prolonged mechanical ventilation due to other diseases. Risk factors for prolonged mechanical ventilation after a severe case of SARS-CoV-2 infection seemed to be male gender, nicotine abuse and cardiovascular disease.


Assuntos
COVID-19 , Respiração Artificial , Insuficiência Respiratória , Feminino , Humanos , Masculino , Pandemias , Insuficiência Respiratória/terapia , SARS-CoV-2 , Desmame do Respirador
6.
HIV Med ; 22(5): 397-408, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33421299

RESUMO

OBJECTIVES: Despite its importance as an HIV anatomic sanctuary, little is known about the characteristics of the HIV reservoir in the terminal ileum (TI). In blood, the immune checkpoint inhibitor programmed-death-1 (PD-1) has been linked to the HIV reservoir and T-cell immune dysfunction. We thus evaluated PD-1 expression and cell-associated HIV DNA in memory CD4 T-cell subsets from TI, peripheral blood (PB) and rectum (RE) of untreated and treated HIV-positive patients to identify associations between PD-1 and HIV reservoir in other sites. METHODS: Using mononuclear cells from PB, TI and RE of untreated HIV-positive (N = 6), treated (n = 18) HIV-positive and uninfected individuals (n = 16), we identified and sorted distinct memory CD4 T-cell subsets by flow cytometry, quantified their cell-associated HIV DNA using quantitative PCR and assessed PD-1 expression levels using geometric mean fluorescence intensity. Combined HIV-1 RNA in situ hybridization and immunohistochemistry was performed on ileal biopsy sections. RESULTS: Combined antiretroviral therapy (cART)-treated patients with undetectable HIV RNA and significantly lower levels of HIV DNA in PB showed particularly high PD-1 expression in PB and TI, and high HIV DNA levels in TI, irrespective of clinical characteristics. By contrast, in treatment-naïve patients HIV DNA levels in memory CD4 T-cell subsets were high in PB and TI. CONCLUSION: Elevated PD-1 expression on memory CD4 T-cells in PB and TI despite treatment points to continuous immune dysfunction and underlines the importance of evaluating immunotherapy in reversing HIV latency and T-cell reconstitution. As HIV DNA particularly persists in TI despite cART, investigating samples from TI is crucial in understanding HIV immunopathogenesis.


Assuntos
Infecções por HIV , HIV-1 , Linfócitos T CD4-Positivos , DNA , HIV-1/genética , Humanos , Íleo/metabolismo , Receptor de Morte Celular Programada 1 , Subpopulações de Linfócitos T/metabolismo
7.
J Neonatal Perinatal Med ; 11(3): 289-293, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30040748

RESUMO

Alveolar capillary dysplasia (ACD) is a rare neonatal lung disease characterized anatomically by a defective and hypoplastic development of pulmonary alveoli leading to persistent pulmonary hypertension (PPHN) and finally lethal respiratory failure. It is often associated with congenital left heart obstruction. Given the fatal prognosis an early diagnosis is important. However, due to the fast onset of PPHN in neonates and lack of pathognomonic signs for its cause, safe and fast detection of ACD is challenging. Therefore, following the exclusion of cardiac and common pulmonary causes, lung biopsy becomes essential for diagnosis.We hereby report a case of ACD with atrial septal defect type one and hypoplastic aortic arch with an ante-mortem diagnosis and discuss the current state of medicine in relation to ACD.


Assuntos
Síndrome da Persistência do Padrão de Circulação Fetal/diagnóstico , Alvéolos Pulmonares/anormalidades , Alvéolos Pulmonares/irrigação sanguínea , Obstrução do Fluxo Ventricular Externo/diagnóstico , Acidose , Dispneia , Evolução Fatal , Humanos , Hipóxia , Recém-Nascido , Síndrome da Persistência do Padrão de Circulação Fetal/fisiopatologia , Alvéolos Pulmonares/fisiopatologia , Tomografia Computadorizada por Raios X , Obstrução do Fluxo Ventricular Externo/fisiopatologia
8.
Chem Commun (Camb) ; 54(18): 2240-2243, 2018 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-29431760

RESUMO

The electron-catalyzed formation of phenanthridines starting from isonitriles initiated by an electrochemical reduction of the Togni reagent is presented. The required number of faradays per mole of starting material and the respective yields clearly show the catalytic character of the electron in this reaction. The mechanism is supported by cyclic voltammetry experiments.

9.
Oncogene ; 37(1): 39-51, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-28846107

RESUMO

Malignant tumors, such as colorectal cancer (CRC), are heterogeneous diseases characterized by distinct metabolic phenotypes. These include Warburg- and reverse Warburg phenotypes depending on differential distribution of the lactate carrier proteins monocarboxylate transporter-4 and -1 (MCT4 and MCT1). Here, we elucidated the role of the antioxidant transcription factor nuclear factor E2-related factor-2 (Nrf2) as the key regulator of cellular adaptation to inflammatory/environmental stress in shaping the metabolism toward a reverse Warburg phenotype in malignant and premalignant colonic epithelial cells. Immunohistochemistry of human CRC tissues revealed reciprocal expression of MCT1 and MCT4 in carcinoma and stroma cells, respectively, accompanied by strong epithelial Nrf2 activation. In colorectal tissue from inflammatory bowel disease patients, MCT1 and Nrf2 were coexpressed as well, relating to CD68+inflammatory infiltrates. Indirect coculture of human NCM460 colonocytes with M1- but not M2 macrophages induces MCT1 as well as G6PD, LDHB and TALDO expression, whereas MCT4 expression was decreased. Nrf2 knockdown or reactive oxygen species (ROS) scavenging blocked these coculture effects in NCM460 cells. Likewise, Nrf2 knockdown inhibited similar effects of tBHQ-mediated Nrf2 activation on NCM460 and HCT15 CRC cells. M1 coculture or Nrf2 activation/overexpression greatly altered the lactate uptake but not glucose uptake and mitochondrial activities in these cells, reflecting the reverse Warburg phenotype. Depending on MCT1-mediated lactate uptake, Nrf2 conferred protection from TRAIL-induced apoptosis in NCM460 and HCT15 cells. Moreover, metabolism-dependent clonal growth of HCT15 cells was induced by Nrf2-dependent activation of MCT1-driven lactate exchange. These findings indicate that Nrf2 has an impact on the metabolism already in premalignant colonic epithelial cells exposed to inflammatory M1 macrophages, an effect accompanied by growth and survival alterations. Favoring the reverse Warburg effect, these Nrf2-dependent alterations add to malignant transformation of the colonic epithelium.


Assuntos
Neoplasias Colorretais/metabolismo , Regulação Neoplásica da Expressão Gênica , Transportadores de Ácidos Monocarboxílicos/genética , Proteínas Musculares/genética , Fator 2 Relacionado a NF-E2/metabolismo , Simportadores/genética , Apoptose/genética , Biópsia , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Técnicas de Cocultura , Colo/citologia , Colo/metabolismo , Colo/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Fibroblastos , Técnicas de Silenciamento de Genes , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Ácido Láctico/metabolismo , Macrófagos , Transportadores de Ácidos Monocarboxílicos/metabolismo , Proteínas Musculares/metabolismo , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células Estromais/metabolismo , Células Estromais/patologia , Simportadores/metabolismo , Microambiente Tumoral/genética
11.
Food Chem ; 175: 500-6, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25577112

RESUMO

The determination of the origin of coffee beans by NMR fingerprinting has been shown promising and classification has been reported for samples of different countries and continents. Here we show that this technique can be extended and applied to discriminate coffee samples from one country against all others, including its closest neighbors. Very high classification rates are reported using a large number of spectra (>300) acquired over a two-year period. As original aspects it can be highlighted that this study was performed in fully automatic mode and with non-deuterated coffee extracts. This is achieved using a series of experiments to procure a robust suppression of the solvent peaks. As is, the method represents a cost effective opportunity for countries to protect their national productions.


Assuntos
Café/química , Espectroscopia de Ressonância Magnética/métodos , Colômbia , Análise de Alimentos
12.
Horm Metab Res ; 47(8): 596-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25251318

RESUMO

Glucocorticoids are known to be involved in myocardial regeneration and destruction. Cardiomyocytes are mostly devoid of nuclear glucocorticoid receptors (GRs) and it is generally assumed that effects of adrenal steroids in heart are mediated through the mineralocorticoid receptor (MR). Here we used immunocytochemistry to study localization of corticosteroid binding globulin (CBG) in semithin sections of human cardiac tissue samples. With staining of consecutive sections we examined colocalization with GR and MR immunoreactivities. While GR staining was almost undetectable, a portion of myocytes with MR immunostained nuclei was found. Almost all cardiomyocytes exhibited CBG immunostaining in cytoplasm and on the cell membrane. Most pronounced CBG immunoreactivities were found in Purkinje fibers and in smooth muscle cells of arterial walls. With RT-PCR, we found in homogenates of cardiac tissue detectable levels of CBG encoding mRNA. Our findings indicate that CBG is expressed in human heart. Known cardiac effects of adrenal steroids may in part be mediated through the binding globulin and its putative membrane receptor in addition to nuclear steroid receptors and direct genomic action. Highlights of our study: Human cardiomyocytes express mineralocorticoid receptors, but are mostly free of nuclear glucocorticoid receptors. CBG is expressed in myocardium and in Purkinje fibers. CBG in heart is colocalized with mineralocorticoid receptor. Endothelia and smooth muscle cells of arterial walls show colocalization of CBG and MR.


Assuntos
Miócitos Cardíacos/metabolismo , Ramos Subendocárdicos/metabolismo , Receptores de Glucocorticoides/metabolismo , Receptores de Mineralocorticoides/metabolismo , Transcortina/metabolismo , Endotélio Vascular/metabolismo , Humanos , Miócitos de Músculo Liso/metabolismo
14.
Cell Death Dis ; 5: e1455, 2014 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-25299780

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest malignancies with an overall life expectancy of 6 months despite current therapies. NF-κB signalling has been shown to be critical for this profound cell-autonomous resistance against chemotherapeutic drugs and death receptor-induced apoptosis, but little is known about the role of the c-Rel subunit in solid cancer and PDAC apoptosis control. In the present study, by analysis of genome-wide patterns of c-Rel-dependent gene expression, we were able to establish c-Rel as a critical regulator of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in PDAC. TRAIL-resistant cells exhibited a strong TRAIL-inducible NF-κB activity, whereas TRAIL-sensitive cells displayed only a small increase in NF-κB-binding activity. Transfection with siRNA against c-Rel sensitized the TRAIL-resistant cells in a manner comparable to siRNA targeting the p65/RelA subunit. Gel-shift analysis revealed that c-Rel is part of the TRAIL-inducible NF-κB complex in PDAC. Array analysis identified NFATc2 as a c-Rel target gene among the 12 strongest TRAIL-inducible genes in apoptosis-resistant cells. In line, siRNA targeting c-Rel strongly reduced TRAIL-induced NFATc2 activity in TRAIL-resistant PDAC cells. Furthermore, siRNA targeting NFATc2 sensitized these PDAC cells against TRAIL-induced apoptosis. Finally, TRAIL-induced expression of COX-2 was diminished through siRNA targeting c-Rel or NFATc2 and pharmacologic inhibition of COX-2 with celecoxib or siRNA targeting COX-2, enhanced TRAIL apoptosis. In conclusion, we were able to delineate a novel c-Rel-, NFATc2- and COX-2-dependent antiapoptotic signalling pathway in PDAC with broad clinical implications for pharmaceutical intervention strategies.


Assuntos
Carcinoma Ductal Pancreático/metabolismo , NF-kappa B/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas c-rel/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Antineoplásicos/farmacologia , Apoptose , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/fisiopatologia , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Resistencia a Medicamentos Antineoplásicos , Humanos , NF-kappa B/genética , Fatores de Transcrição NFATC/genética , Fatores de Transcrição NFATC/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/fisiopatologia , Proteínas Proto-Oncogênicas c-rel/genética , Fator de Transcrição RelA/metabolismo
15.
Phys Rev Lett ; 113(2): 026401, 2014 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-25062214

RESUMO

Using femtosecond time-resolved x-ray diffraction, we directly monitor the coherent lattice dynamics through an ultrafast charge-density-wave-to-metal transition in the prototypical Peierls system K(0.3)MoO(3) over a wide range of relevant excitation fluences. While in the low fluence regime we directly follow the structural dynamics associated with the collective amplitude mode; for fluences above the melting threshold of the electronic density modulation we observe a transient recovery of the periodic lattice distortion. We can describe these structural dynamics as a motion along the coordinate of the Peierls distortion triggered by the prompt collapse of electronic order after photoexcitation. The results indicate that the dynamics of a structural symmetry-breaking transition are determined by a high-symmetry excited state potential energy surface distinct from that of the initial low-temperature state.

16.
Pneumologie ; 68(3): 193-8, 2014 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-24595853

RESUMO

Long-term oxygen treatment (LTOT) has been demonstrated to improve prognosis in patients with chronic respiratory insufficiency. In terms of pathogenesis, improved oxygenation, reduction of pulmonary artery pressure as well as reduction of respiratory work are important. Since there are considerable differences between the LTOT systems, individually tailored therapy is needed. In particular, the mobility aspects of the patients must be taken into consideration. It is important to distinguish between stationary/mobile devices with a liquid oxygen system and stationary/mobile devices with oxygen concentrator. Oxygen titration should be performed in relation to rest and activity phases (e. g. 6 minute walk test) as well as in relation to the sleep phase. Employing devices with demand-controlled valves should be critically examined. This can be undertaken only under physician orders and requires continuous monitoring.


Assuntos
Oxigenoterapia/instrumentação , Oxigenoterapia/métodos , Insuficiência Respiratória/terapia , Desenho de Equipamento , Análise de Falha de Equipamento , Medicina Baseada em Evidências , Serviços de Assistência Domiciliar , Humanos
18.
J Chem Neuroanat ; 52: 44-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23680380

RESUMO

Sepsis is known to affect neuroendocrine circuits: injections of lipopolysaccaride are potent stimulators of oxytocin secretion from the posterior lobe, acute sepsis leads to uterus contractions and spontaneous abort. Here, we report changes in expression and distribution of hypothalamic oxytocin in rats that had been subjected to caecal ligation and puncture which led to acute sepsis. Septic animals showed loss of oxytocin immunostaining in perikarya of the supraoptic and paraventricular nuclei and an increase of oxytocin positive fibres, suggesting a shift of oxytocin pools into the axonal compartment. Immunostaining of the posterior lobe revealed reduction of oxytocin in septic rats. Magnocellular neurons in supraoptic- and to a lesser extent in paraventricular nuclei showed nuclear immunoreactivity for the protooncogene c-Fos, indicating stimulation of transcriptional activity upon sepsis. Contrary to magnocellular oxytocin immunoreactivity, we observed increased oxytocin immunoreactivity in cell bodies and processes of periventricular nucleus and in perivascular neurons. Oxytocin neurons in other regions of the hypothalamus and the preoptic region did not appear to be affected by acute sepsis. Our findings suggest a differential activation of neurohypophyseal and cerebrospinal fluid contacting oxytocin systems while centrally projecting oxytocin neurons may not be affected. Systemic oxytocin levels may serve as additional diagnostic marker for sepsis.


Assuntos
Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Sepse/metabolismo , Animais , Hipotálamo/química , Hipotálamo/citologia , Hipotálamo/metabolismo , Masculino , Ocitocina/análise , Núcleo Hipotalâmico Paraventricular/química , Núcleo Hipotalâmico Paraventricular/citologia , Ratos , Ratos Wistar
19.
J Exp Biol ; 216(Pt 2): 245-52, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22996440

RESUMO

Corticosteroid binding globulin (CBG, transcortin) has been shown to be expressed in the brain of rat and human species. In this study, we examined the CBG brain expression and cDNA structure in mice, comparing wild-type (Cbg(+/+)) and Cbg knockout mice (Cbg(-/-), obtained by genetic disruption of the SerpinA6 alias Cbg gene). We used double immunofluorescence labeling with specific neuronal and glial markers to analyze the cellular localization of CBG in various regions of the mouse brain. In wild-type (Cbg(+/+)) mice, we found CBG immunoreactivity in neuronal perikarya of the magnocellular hypothalamic nuclei, amygdala, hippocampus, cerebral cortex, cerebellum and pituitary. A portion of glial cells (astrocytes, oligodendrocytes) contained CBG immunoreactivity, including some of the ependymal cells and choroid plexus cells. No CBG immunoreactivity was detected in Cbg(-/-) brain tissues. Using RT-PCR, we showed that the full-length Cbg mRNA is present in those regions, indicating an intrinsic expression of the steroid-binding globulin. Furthermore, sequencing analysis showed that Cbg cDNA obtained from the mouse hypothalamus was homologous to Cbg cDNA obtained from the liver. Finally, we have evaluated the relative levels of CBG expression in various brain regions and in the liver by quantitative PCR. We found that brain levels of Cbg mRNA are low compared with the liver but significantly higher than in CBG-deficient mice. Although derived from the same gene as liver CBG, brain CBG protein may play a specific or complementary role that requires the production and analysis of brain-specific Cbg knockout models.


Assuntos
Encéfalo/metabolismo , Transcortina/análise , Transcortina/genética , Animais , Encéfalo/citologia , Química Encefálica , DNA Complementar/genética , Feminino , Expressão Gênica , Histocitoquímica , Masculino , Camundongos , Camundongos Knockout , RNA Mensageiro/análise , RNA Mensageiro/genética
20.
Horm Metab Res ; 45(3): 245-51, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22990989

RESUMO

The hypothalamic-pituitary-adrenal axis is supposed to be involved in the pathogenesis of the metabolic disorders. Differences in adipose tissues and parameters of insulin resistance are linked to steroid homeostasis. We assessed the correlation of fat tissue distribution, gender, and glucose control with levels of systemic corticosteroid-binding globulin (CBG), free cortisol (FuF), and total cortisol (FuM). Data of 1 114 patients with overweight, lipid disorders, and impaired glucose tolerance were collected. Blood samples were sorted according to gender and anthropometric measures. Variable-association was calculated using the Spearman Rank Correlation coefficient and tested for significance (p<0.05 and p<0.01). CBG and FuF were consistently negatively correlated to each weight parameter. Especially in women, fat mass index (FMI) was significantly negatively correlated with CBG-levels. While CBG levels dropped with increasing age, FuF showed an inverse behavior. Glycohemoglobin levels showed negative correlations with CBG while fasting glucose did not. Both changes were associated with significant increases in FuF. All negative correlations to cortisol and its binding globulin with regards to weigh- and glucose-control parameters were absent in smokers compared to nonsmokers. Our observations suggest that different weight parameters correspond to adrenal steroids and their buffer systems. Especially in women, CBG levels might serve as prognostic marker for the fat mass. In addition, CBG levels may predict long term blood glucose control more reliably than FG. However, the value of CBG as an indirect surrogate-marker for obesity and glucose is limited in smokers.


Assuntos
Glucocorticoides/sangue , Homeostase , Obesidade/sangue , Fumar/sangue , Adolescente , Adulto , Idoso , Envelhecimento/sangue , Envelhecimento/metabolismo , Glicemia/metabolismo , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Análise de Regressão , Estatísticas não Paramétricas , Esteroides/sangue , Adulto Jovem
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