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1.
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
2.
Acta Radiol ; 65(4): 329-333, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38111253

RESUMO

BACKGROUND: With increasing incidence of esophageal cancer, a growing number of patients are at risk of developing delayed gastric conduit emptying (DGCE) in the early postoperative phase after esophagectomy. This condition is of great postoperative concern due to its association with adverse outcomes. PURPOSE: To give a narrative review of the literature concerning radiological diagnosis of DGCE after esophagectomy and a proposal for an improved, functional protocol with objective measurements. MATERIAL AND METHODS: The protocol was designed at Virginia Mason Medical Center in Seattle and is based on the Timed Barium Esophagogram (TBE) concept, which has been adapted to assess the passage of contrast from the gastric conduit into the duodenum. RESULTS: The literature review showed a general lack of standardization and scientific evidence behind the use of radiology to assess DGCE. We found that our proposed standardized upper gastrointestinal (UGI) contrast study considers both the time aspect in DGCE and provides morphologic information of the gastric conduit. This radiological protocol was tested on 112 patients in a trial performed at two high-volume centers for esophageal surgery and included an UGI contrast study 2-3 days postoperatively. The study demonstrated that this UGI contrast study can be included in the standardized clinical pathway after esophagectomy. CONCLUSION: This new, proposed UGI contrast study has the potential to diagnose early postoperative DGCE in a standardized manner and to improve overall patient outcomes after esophagectomy.


Assuntos
Meios de Contraste , Esofagectomia , Complicações Pós-Operatórias , Humanos , Esofagectomia/métodos , Complicações Pós-Operatórias/diagnóstico por imagem , Feminino , Masculino , Esvaziamento Gástrico , Pessoa de Meia-Idade , Idoso , Neoplasias Esofágicas/cirurgia , Neoplasias Esofágicas/diagnóstico por imagem , Sulfato de Bário
3.
Angew Chem Int Ed Engl ; 63(5): e202315814, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38061995

RESUMO

Highly efficient perovskite solar cells typically rely on spiro-OMeTAD as a hole transporter, achieving a 25.7 % efficiency record. However, these cells are susceptible to harsh 85 °C conditions. Here, we present a peri-xanthenoxanthene-based semiconducting homopolymer (p-TNI2) with matched energy levels and a high molecular weight, synthesized nearly quantitatively through facile oxidative polymerization. Compared to established materials, p-TNI2 excels in hole mobility, morphology, modulus, and waterproofing. Implementing p-TNI2 as the hole transport layer results in n-i-p perovskite solar cells with an initial average efficiency of 24.6 %, rivaling 24.4 % for the spiro-OMeTAD control cells under identical conditions. Furthermore, the p-TNI2-based cells exhibit enhanced thermostability at 85 °C and operational robustness.

4.
Appl Opt ; 62(14): 3737-3746, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37706991

RESUMO

Measurement of chemical species and temperature mapping in flames is essential to understanding the combustion process. Multiple cameras are conventionally employed for measurement in such scenarios making the experimental setup not only cost-intensive but also challenging. To circumvent this, structured illumination (SI)-based methods are reported for multispecies chemiluminescence (CL) imaging using a single camera. In this paper, we demonstrate four-channel SI-based imaging for simultaneous snapshot C H ∗ and C2∗ CL imaging and two-color pyrometry for temperature profiles in a butane diffusion flame. We demonstrate our approach using individual species and multiple species imaging. Taking the advantage of the axisymmetric nature of the flame, the Abel transform is performed on the line-of-sight averaged images to obtain deconvoluted images. The deconvoluted maps of temperature are compared with the temperature data obtained by using a physical thermocouple probe.

5.
Acta Radiol ; 64(1): 32-41, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34904868

RESUMO

BACKGROUND: Immunotherapy of hepatocellular carcinoma (HCC) is an emerging method with promising results. Immunotherapy can have an antitumor effect without affecting tumor size, calling for functional imaging methods for response evaluation. PURPOSE: To evaluate the response to intratumoral injections with the immune primer ilixadencel in HCCs with diffusion-weighted magnetic resonance imaging (DW-MRI) using intravoxel incoherent motion (IVIM) and histogram analysis. MATERIAL AND METHODS: A total of 17 patients with advanced HCC were treated with intratumoral injections with ilixadencel on three occasions 2-5 weeks apart. The patients were examined with IVIM before each injection as well as approximately three months after the first injection. RESULTS: The 10th percentile of perfusion-related parameter D* decreased significantly after the first and second intratumoral injections of ilixadencel compared to baseline (P < 0.05). There was a non-significant trend of lower median region of interest f (perfusion fraction) before injection 2 compared to baseline (P = 0.07). There were significant correlations between the 10th percentile and median of D at baseline and change in tumor size after three months (r = 0.79, P < 0.01 and r = 0.72, P < 0.05, respectively). CONCLUSION: DW-MRI with IVIM and histogram analysis revealed significant reductions of D* early after treatment as well as an association between D at baseline and smaller tumor growth at three months. The lower percentiles (10th and 50th) were found more important. Further research is needed to confirm our preliminary findings of reduced perfusion after ilixadencel vaccinations, suggesting a treatment effect on HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética , Movimento (Física) , Células Dendríticas/patologia
6.
New Phytol ; 233(1): 236-250, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34655491

RESUMO

Warming climate increases the risk for harmful leaf temperatures in terrestrial plants, causing heat stress and loss of productivity. The heat sensitivity may be particularly high in equatorial tropical tree species adapted to a thermally stable climate. Thermal thresholds of the photosynthetic system of sun-exposed leaves were investigated in three tropical montane tree species native to Rwanda with different growth and water use strategies (Harungana montana, Syzygium guineense and Entandrophragma exselsum). Measurements of chlorophyll fluorescence, leaf gas exchange, morphology, chemistry and temperature were made at three common gardens along an elevation/temperature gradient. Heat tolerance acclimated to maximum leaf temperature (Tleaf ) across the species. At the warmest sites, the thermal threshold for normal function of photosystem II was exceeded in the species with the highest Tleaf despite their higher heat tolerance. This was not the case in the species with the highest transpiration rates and lowest Tleaf . The results point to two differently effective strategies for managing thermal stress: tolerance through physiological adjustment of leaf osmolality and thylakoid membrane lipid composition, or avoidance through morphological adaptation and transpiratory cooling. More severe photosynthetic heat stress in low-transpiring montane climax species may result in a competitive disadvantage compared to high-transpiring pioneer species with more efficient leaf cooling.


Assuntos
Termotolerância , Árvores , Aclimatação , Fotossíntese , Folhas de Planta , Temperatura , Clima Tropical
7.
Mar Drugs ; 20(7)2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35877717

RESUMO

A local strain of Nannochloropsis granulata (Ng) has been reported as the most productive microalgal strain in terms of both biomass yield and lipid content when cultivated in photobioreactors that simulate the light and temperature conditions during the summer on the west coast of Sweden. To further increase the biomass and the biotechnological potential of this strain in these conditions, mixotrophic growth (i.e., the simultaneous use of photosynthesis and respiration) with glycerol as an external carbon source was investigated in this study and compared with phototrophic growth that made use of air enriched with 1-2% CO2. The addition of either glycerol or CO2-enriched air stimulated the growth of Ng and theproduction of high-value long-chain polyunsaturated fatty acids (EPA) as well as the carotenoid canthaxanthin. Bioassays in human prostate cell lines indicated the highest antitumoral activity for Ng extracts and fractions from mixotrophic conditions. Metabolomics detected betaine lipids specifically in the bioactive fractions, suggesting their involvement in the observed antitumoral effect. Genes related to autophagy were found to be upregulated by the most bioactive fraction, suggesting a possible therapeutic target against prostate cancer progression. Taken together, our results suggest that the local Ng strain can be cultivated mixotrophically in summer conditions on the west coast of Sweden for the production of high-value biomass containing antiproliferative compounds, carotenoids, and EPA.


Assuntos
Microalgas , Estramenópilas , Biomassa , Dióxido de Carbono/metabolismo , Carotenoides/metabolismo , Glicerol , Humanos , Microalgas/metabolismo , Estramenópilas/metabolismo , Suécia
8.
Molecules ; 27(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36234895

RESUMO

We investigated the effect of adding p-anisaldehyde (AA) solvent to the ink containing poly[[2,60-4,8-di(5-ethylhexylthienyl)benzo[1,2-b:3,3-b]dithiophene][3-fluoro-2[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]](PTB7-Th) and 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:20,30-d0]-s-indaceno[1,2-b:5,6-b0]-dithiophene(ITIC) on the morphology of the active layer. The present study focuses on determining the effect of the additive on the compositions at the surface of the PTB7-Th: ITIC composite and its morphology, forming one side of the interface of the blend with the MoOX electrode, and the influence of the structural change on the performance of devices. Studies of device performance show that the addition of the additive AA leads to an improvement in device performance. Upon the addition of AA, the concentration of PTB7-Th at the surface of the bulk heterojunction (BHJ) increases, causing an increase in surface roughness of the surface of the BHJ. This finding contributes to an understanding of the interaction between the donor material and high work function electrode/interface material. The implications for the interface are discussed.

9.
Pediatr Res ; 90(6): 1177-1185, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34392310

RESUMO

BACKGROUND: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for fetal brain growth and development. Our aim was to evaluate the association between serum DHA and AA levels and brain volumes in extremely preterm infants. METHODS: Infants born at <28 weeks gestational age in 2013-2015, a cohort derived from a randomized controlled trial comparing two types of parenteral lipid emulsions, were included (n = 90). Serum DHA and AA levels were measured at postnatal days 1, 7, 14, and 28, and the area under the curve was calculated. Magnetic resonance (MR) imaging was performed at term-equivalent age (n = 66), and volumes of six brain regions were automatically generated. RESULTS: After MR image quality assessment and area under the curve calculation, 48 infants were included (gestational age mean [SD] 25.5 [1.4] weeks). DHA levels were positively associated with total brain (B = 7.966, p = 0.012), cortical gray matter (B = 3.653, p = 0.036), deep gray matter (B = 0.439, p = 0.014), cerebellar (B = 0.932, p = 0.003), and white matter volume (B = 3.373, p = 0.022). AA levels showed no association with brain volumes. CONCLUSIONS: Serum DHA levels during the first 28 postnatal days were positively associated with volumes of several brain structures in extremely preterm infants at term-equivalent age. IMPACT: Higher serum levels of DHA in the first 28 postnatal days are positively associated with brain volumes at term-equivalent age in extremely preterm born infants. Especially the most immature infants suffer from low DHA levels in the first 28 postnatal days, with little increase over time. Future research is needed to explore whether postnatal fatty acid supplementation can improve brain development and may serve as a nutritional preventive and therapeutic treatment option in extremely preterm infants.


Assuntos
Encéfalo/anatomia & histologia , Ácidos Docosa-Hexaenoicos/sangue , Lactente Extremamente Prematuro , Ácido Araquidônico , Estudos de Coortes , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Tamanho do Órgão
10.
Physiol Plant ; 173(2): 543-554, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33826748

RESUMO

At Nordic latitudes, year-round outdoor cultivation of microalgae is debatable due to seasonal variations in productivity. Shall the same species/strains be used throughout the year, or shall seasonal-adapted ones be used? To elucidate this, a laboratory study was performed where two out of 167 marine microalgal strains were selected for intended cultivation at the west coast of Sweden. The two local strains belong to Nannochloropsis granulata (Ng) and Skeletonema marinoi (Sm142). They were cultivated in photobioreactors and compared in conditions simulating variations in light and temperature of a year divided into three growth seasons (spring, summer and winter). The strains grew similarly well in summer (and also in spring), but Ng produced more biomass (0.225 vs. 0.066 g DW L-1 day-1 ) which was more energy rich (25.0 vs. 16.6 MJ kg-1 DW). In winter, Sm142 grew faster and produced more biomass (0.017 vs. 0.007 g DW L-1 day-1 ), having similar energy to the other seasons. The higher energy of the Ng biomass is attributed to a higher lipid content (40 vs. 16% in summer). The biomass of both strains was richest in proteins (65%) in spring. In all seasons, Sm142 was more effective in removing phosphorus from the cultivation medium (6.58 vs. 4.14 mg L-1 day-1 in summer), whereas Ng was more effective in removing nitrogen only in summer (55.0 vs. 30.8 mg L-1 day-1 ). Our results suggest that, depending on the purpose, either the same or different local species can be cultivated, and are relevant when designing outdoor studies.


Assuntos
Microalgas , Biomassa , Laboratórios , Estações do Ano , Suécia , Temperatura
11.
Environ Sci Technol ; 55(1): 757-766, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33337864

RESUMO

Unwanted growth of fouling organisms on underwater surfaces is an omnipresent challenge for the marine industry, costing billions of dollars every year in the transportation sector alone. Copper, the most widely used biocide in antifouling paints, is at the brink of a total ban in being used in antifouling coatings, as it has become an existential threat to nontargeted species due to anthropogenic copper inputs into protected waters. In the current study, using a porous and cross-linked poly(ethylene imine) structure under marine and fouling environments, available copper from natural seawater was absorbed and electrochemically released back as a potent biocide at 1.3 V vs Ag|AgCl, reducing marine growth by 94% compared to the control electrode (coupon) at 0 V. The coating can also function as an electrochemical copper sensor enabling real-time monitoring of the electrochemical uptake and release of copper ions from natural seawater. This allows tailoring of the electrochemical program to the changing marine environments, i.e., when the vessels move from high-copper-contaminated waters to coastal regions with low concentrations of copper.


Assuntos
Incrustação Biológica , Desinfetantes , Incrustação Biológica/prevenção & controle , Cobre/análise , Pintura , Água do Mar
12.
Surg Endosc ; 35(12): 6650-6659, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33259018

RESUMO

BACKGROUND: Imaging modalities for characterizing pancreatic cystic lesions (PCLs) is a known uncertainty. The aim of this prospective study was to compare the diagnostic performance of endoscopic ultrasound morphology, cytology and cyst fluid carcinoembryonic antigen (EUS-FNA-CEA) with cross-sectional imaging in resected PCLs. METHODS: The cross-sectional imaging and EUS-FNA-CEA results were collected in an academic tertiary referral centre using histology of the surgical specimen as the diagnostic standard. RESULTS: Of 289 patients undergoing evaluation for PCL with cross-sectional imaging and EUS-FNA between February 2007 and March 2017, 58 underwent surgical resection providing a final diagnosis of the PCLs: 45 mucinous, 5 serous, 1 pseudocyst, 2 endocrine, 2 solid pseudopapillary neoplasms and 3 other. EUS-FNA-CEA was more accurate than cross-sectional imaging in diagnosing mucinous PCLs (95% vs. 83%, p = 0.04). Ninety-two percent of the PCLs with high-grade dysplasia or adenocarcinoma were smaller than 3 cm in diameter. The sensitivity of EUS-FNA-CEA and cross-sectional imaging for detecting PCLs with high-grade dysplasia or adenocarcinoma were 33% and 5% (p = 0.03), respectively. However, there was no difference in accuracy between the modalities (62% vs. 66%, p = 0.79). The sensitivity for detecting pancreatic adenocarcinomas only was 64% for EUS-FNA-CEA and 9% for cross-sectional imaging (p = 0.03). Overall, EUS-FNA-CEA provided a correct diagnosis in more patients with PCLs than cross-sectional imaging (72% vs. 50%, p = 0.01). CONCLUSIONS: EUS-FNA-CEA is accurate and should be considered a complementary test in the diagnosis of PCLs. However, the detection of PCLs with high-grade dysplasia or adenocarcinoma needs to be improved. Cyst size does not seem to be a reliable predictor of high-grade dysplasia or adenocarcinoma.


Assuntos
Cisto Pancreático , Neoplasias Pancreáticas , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Endossonografia , Humanos , Pâncreas , Cisto Pancreático/diagnóstico por imagem , Cisto Pancreático/cirurgia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/cirurgia , Estudos Prospectivos
13.
Ann Bot ; 126(1): 179-190, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32296835

RESUMO

BACKGROUND AND AIMS: The stomatal conductance (gs) of most plant species decreases in response to elevated atmospheric CO2 concentration. This response could have a significant impact on plant water use in a future climate. However, the regulation of the CO2-induced stomatal closure response is not fully understood. Moreover, the potential genetic links between short-term (within minutes to hours) and long-term (within weeks to months) responses of gs to increased atmospheric CO2 have not been explored. METHODS: We used Arabidopsis thaliana recombinant inbred lines originating from accessions Col-0 (strong CO2 response) and C24 (weak CO2 response) to study short- and long-term controls of gs. Quantitative trait locus (QTL) mapping was used to identify loci controlling short- and long-term gs responses to elevated CO2, as well as other stomata-related traits. KEY RESULTS: Short- and long-term stomatal responses to elevated CO2 were significantly correlated. Both short- and long-term responses were associated with a QTL at the end of chromosome 2. The location of this QTL was confirmed using near-isogenic lines and it was fine-mapped to a 410-kb region. The QTL did not correspond to any known gene involved in stomatal closure and had no effect on the responsiveness to abscisic acid. Additionally, we identified numerous other loci associated with stomatal regulation. CONCLUSIONS: We identified and confirmed the effect of a strong QTL corresponding to a yet unknown regulator of stomatal closure in response to elevated CO2 concentration. The correlation between short- and long-term stomatal CO2 responses and the genetic link between these traits highlight the importance of understanding guard cell CO2 signalling to predict and manipulate plant water use in a world with increasing atmospheric CO2 concentration. This study demonstrates the power of using natural variation to unravel the genetic regulation of complex traits.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Ácido Abscísico , Dióxido de Carbono , Mapeamento Cromossômico , Estômatos de Plantas/genética
14.
Phys Chem Chem Phys ; 22(26): 14579-14590, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32597442

RESUMO

The formation of strongly elastic physical gels based on poly(alkylene oxide)-grafted hyaluronan or carboxymethylcellulose, exhibiting both shear-thickening and strain-hardening have been studied using rheometry and explained using a slightly different interpretation of the transient network theory. The graft copolymers were prepared by a quantitative coupling reaction. Their aqueous solutions displayed a thermoreversible continuous transition from Newtonian fluid to viscoelastic solid which could be controlled by the reaction conditions. The evolution of all material properties of the gel could be categorized into two distinct temperature regimes with a fast evolution at low temperatures followed by a slow evolution at high temperatures. The activation energy of the zero shear viscosity and the relaxation time of the graft inside the interconnecting microdomains were almost identical to each other in both temperature regimes. This suggests that the number of microdomains remained approximately constant whereas the aggregation number inside the microdomains increased according to the binodal curve of the thermosensitive graft.


Assuntos
Carboximetilcelulose Sódica/química , Ácido Hialurônico/química , Hidrogéis/química , Polímeros/química , Temperatura Baixa , Temperatura Alta , Transição de Fase , Reologia , Substâncias Viscoelásticas/química , Viscosidade
15.
Scand J Clin Lab Invest ; 80(8): 672-680, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33258387

RESUMO

Quantitation of endogenous steroids and their precursors is essential for diagnosis of a wide range of endocrine disorders. Usually, these analyses have been carried out using immunoassays. However, immunoassays often overestimate concentrations due to assay interference by other endogenous steroids, especially for low concentrations. Mass spectrometry based methods offer superior specificity, accuracy, and sensitivity. We therefore present a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with automated sample preparation for determination of 17α-hydroxyprogesterone (17OHP), cortisol, cortisone, dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), testosterone (T), and estrone sulfate (E1S). Samples were prepared using protein precipitation and 96-well filter plates, fully automated in a pipetting robot and analyzed by LC-MS/MS. Serum samples from 187 healthy children and adolescents aged 5-18 years were used to study hormone changes in relation to sex and pubertal stage. Lower limit of quantification for 17OHP was 0.7 nmol/L, for cortisol 11 nmol/L, for cortisone 2 nmol/L, for DHEAS 0.1 µmol/L, and for A4, T, and E1S, 0.2 nmol/L. This study showed a general increase in 17OHP, DHEAS, A4, T and E1S in both genders during puberty. In boys, A4 and T increased significantly throughout pubertal development. Girls had significantly higher A4 and E1S concentrations, while boys had higher T concentrations. No sex- or puberty-specific differences were seen in cortisol or cortisone concentrations. To the best of our knowledge, this is the first presentation of changes in serum E1S concentrations during pubertal development in healthy children.


Assuntos
Androstenodiona/sangue , Cortisona/sangue , Sulfato de Desidroepiandrosterona/sangue , Estrona/análogos & derivados , Hidrocortisona/sangue , Hidroxiprogesteronas/sangue , Testosterona/sangue , Adolescente , Criança , Pré-Escolar , Cromatografia Líquida/normas , Estrona/sangue , Feminino , Humanos , Limite de Detecção , Masculino , Puberdade/sangue , Robótica/instrumentação , Fatores Sexuais , Espectrometria de Massas em Tandem/normas
16.
J Neurochem ; 149(4): 452-470, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30851210

RESUMO

It is well-known that the extracellular concentration of calcium affects neuronal excitability and synaptic transmission. Less is known about the physiological concentration of extracellular calcium in the brain. In electrophysiological brain slice experiments, the artificial cerebrospinal fluid traditionally contains relatively high concentrations of calcium (2-4 mM) to support synaptic transmission and suppress neuronal excitability. Using an ion-selective electrode, we determined the fraction of ionized calcium in healthy human cerebrospinal fluid to 1.0 mM of a total concentration of 1.2 mM (86%). Using patch-clamp and extracellular recordings in the CA1 region in acute slices of rat hippocampus, we then compared the effects of this physiological concentration of calcium with the commonly used 2 mM on neuronal excitability, synaptic transmission, and long-term potentiation (LTP) to examine the magnitude of changes in this range of extracellular calcium. Increasing the total extracellular calcium concentration from 1.2 to 2 mM decreased spontaneous action potential firing, induced a depolarization of the threshold, and increased the rate of both de- and repolarization of the action potential. Evoked synaptic transmission was approximately doubled, with a balanced effect between inhibition and excitation. In 1.2 mM calcium high-frequency stimulation did not result in any LTP, whereas a prominent LTP was observed at 2 or 4 mM calcium. Surprisingly, this inability to induce LTP persisted during blockade of GABAergic inhibition. In conclusion, an increase from the physiological 1.2 mM to 2 mM calcium in the artificial cerebrospinal fluid has striking effects on neuronal excitability, synaptic transmission, and the induction of LTP. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. Read the Editorial Highlight for this article on page 435.


Assuntos
Cálcio/líquido cefalorraquidiano , Cálcio/farmacologia , Líquido Cefalorraquidiano/química , Células Piramidais/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Adulto , Animais , Feminino , Humanos , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Células Piramidais/metabolismo , Ratos , Ratos Wistar
17.
BMC Cancer ; 19(1): 568, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31185950

RESUMO

BACKGROUND: Patients with hepatocellular carcinoma waiting for liver transplantation are commonly treated with locoregional treatments, such as TACE and ablation, to prevent tumor progression and dropout and to improve long-term outcome after transplantation. We wanted to prospectively assess feasibility of systemic antitumor treatment with sorafenib as neoadjuvant treatment for hepatocellular carcinoma while waiting for liver transplantation, evaluating tolerability, toxicity and posttransplant morbidity. We also wanted to evaluate perfusion CT parameters to assess tumor properties and response early after start of sorafenib treatment in patients with early hepatocellular carcinoma. METHODS: Twelve patients assigned for liver transplantation due to hepatocellular carcinoma, within the UCSF and who fulfilled other criteria, were included January 2012-August 2014. After baseline evaluation, sorafenib treatment was started. Treatment was evaluated by perfusion CT at 1, 4 and 12 weeks and thereafter every 8 weeks. Toxicity and quality of life was assessed at 1 and 4 weeks and every 4 weeks thereafter during treatment. Treatment was stopped when patients were prioritized on the transplantation waiting list or when intolerable side effects or tumor progress warranted other treatments. Posttransplant morbidity after 90 days was registered according to Clavien-Dindo. RESULTS: Baseline perfusion CT parameters in the tumors predicted the outcome according to RECIST/mRECIST at three months, but no change in CTp parameters was detected as a result of sorafenib. Sorafenib as neoadjuvant treatment was associated with intolerability and dose reductions. Therefore the prerequisites for evaluation of the sorafenib effect on both CT parameters and tumor response were impaired. CONCLUSIONS: This study failed to show changes in CTp parameters during sorafenib treatment. Despite the curative treatment intention, tolerability of neoadjuvant sorafenib treatment before liver transplantation was inadequate in this study. TRIAL REGISTRATION: EudraCT number: 2010-024306-36 (date 2011-04-07).


Assuntos
Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Transplante de Fígado , Sorafenibe/efeitos adversos , Sorafenibe/uso terapêutico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Velocidade do Fluxo Sanguíneo , Carcinoma Hepatocelular/fisiopatologia , Tolerância a Medicamentos , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Projetos Piloto , Estudos Prospectivos , Qualidade de Vida , Critérios de Avaliação de Resposta em Tumores Sólidos , Sorafenibe/administração & dosagem , Tomografia Computadorizada por Raios X
18.
Biomacromolecules ; 20(3): 1271-1280, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30681838

RESUMO

A series of thermoresponsive graft copolymers, gelling at physiological conditions in aqueous solution and cell growth media, have been synthesized using quantitative coupling between a small set of amino-functionalized poly(alkylene oxide) copolymers (PAO) and the carboxylate of the biologically important polysaccharides (PSa) carboxymethylcellulose and the less reactive hyaluronate. Quantitative grafting enables the establishment of structure-function relationship which is imperative for controlling the properties of in situ gelling hydrogels. The EDC/NHS-mediated reaction was monitored using SEC-MALLS, which revealed that all PAOs were grafted onto the PSa backbone. Aqueous solutions of the graft copolymers were Newtonian fluids at room temperatures and formed reversible physical gels at elevated temperatures which were noncytotoxic toward chondrocytes. The established structure-function relationship was most clearly demonstrated by inspecting the thermogelling strength and the onset of thermogelling in a phase diagram. The onset of the thermogelling function could be controlled by the global PAO concentration, independent of graft ratio.


Assuntos
Carboximetilcelulose Sódica/química , Ácido Hialurônico/química , Polímeros/química , Alcenos/química , Cromatografia em Gel , Óxidos/química , Relação Estrutura-Atividade , Termodinâmica
19.
Phys Chem Chem Phys ; 21(10): 5705-5715, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30801074

RESUMO

A modified synthesis method for aqueous nanoparticle printing inks, based upon vacuum-assisted solvent removal, is reported. Poly(3-hexylthiophene):phenyl C61 butyric acid methyl ester nanoparticle inks were prepared via this modified miniemulsion method, leading to both an improvement in photoactive layer morphology and a substantial reduction in the ink fabrication time. A combination of UV-visible spectroscopy, photoluminescence spectroscopy and scanning transmission X-ray microscopy measurements revealed a nanoparticle morphology comprising highly intermixed donor-acceptor domains. Consistent with these measurements, dynamic mechanical thermal analysis of the nanoparticles showed a glass transition temperature (Tg) of 104 °C, rather than a pure polymer phase or pure fullerene phase Tg. Together the spectroscopy, microscopy and thermomechanical data indicate that rapid solvent removal generates a more blended nanoparticle morphology. As such, this study highlights a new experimental lever for optimising nanostructure in the photoactive layer of nanoparticulate organic photovoltaic devices by enabling highly intermixed donor-acceptor architectures to be built from customised nanoparticulate inks.

20.
N Engl J Med ; 373(26): 2534-48, 2015 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-26699169

RESUMO

BACKGROUND: Secukinumab is an anti-interleukin-17A monoclonal antibody that has been shown to control the symptoms of ankylosing spondylitis in a phase 2 trial. We conducted two phase 3 trials of secukinumab in patients with active ankylosing spondylitis. METHODS: In two double-blind trials, we randomly assigned patients to receive secukinumab or placebo. In MEASURE 1, a total of 371 patients received intravenous secukinumab (10 mg per kilogram of body weight) or matched placebo at weeks 0, 2, and 4, followed by subcutaneous secukinumab (150 mg or 75 mg) or matched placebo every 4 weeks starting at week 8. In MEASURE 2, a total of 219 patients received subcutaneous secukinumab (150 mg or 75 mg) or matched placebo at baseline; at weeks 1, 2, and 3; and every 4 weeks starting at week 4. At week 16, patients in the placebo group were randomly reassigned to subcutaneous secukinumab at a dose of 150 mg or 75 mg. The primary end point was the proportion of patients with at least 20% improvement in Assessment of Spondyloarthritis International Society (ASAS20) response criteria at week 16. RESULTS: In MEASURE 1, the ASAS20 response rates at week 16 were 61%, 60%, and 29% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P<0.001 for both comparisons with placebo); in MEASURE 2, the rates were 61%, 41%, and 28% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P<0.001 for the 150-mg dose and P=0.10 for the 75-mg dose). The significant improvements were sustained through 52 weeks. Infections, including candidiasis, were more common with secukinumab than with placebo during the placebo-controlled period of MEASURE 1. During the entire treatment period, pooled exposure-adjusted incidence rates of grade 3 or 4 neutropenia, candida infections, and Crohn's disease were 0.7, 0.9, and 0.7 cases per 100 patient-years, respectively, in secukinumab-treated patients. CONCLUSIONS: Secukinumab at a subcutaneous dose of 150 mg, with either subcutaneous or intravenous loading, provided significant reductions in the signs and symptoms of ankylosing spondylitis at week 16. Secukinumab at a subcutaneous dose of 75 mg resulted in significant improvement only with a higher intravenous loading dose. (Funded by Novartis Pharma; ClinicalTrials.gov numbers, NCT01358175 and NCT01649375.).


Assuntos
Anticorpos Monoclonais/uso terapêutico , Interleucina-17/antagonistas & inibidores , Espondilite Anquilosante/tratamento farmacológico , Adulto , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Candidíase/etiologia , Doença de Crohn/induzido quimicamente , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente
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