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1.
Sociol Health Illn ; 2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37897708

RESUMO

A formal Gender Dysphoria classification- as outlined in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders- is a prerequisite for the reimbursement of both gender-affirming medical care and transgender mental health care in the Netherlands. Gender Dysphoria and its conceptual precursors have always been moving targets: moving due to research, policy, care practices and activism both within and outside of medicine. This raises the question of what Gender Dysphoria is exactly. To elucidate this question, we turn to the people who use the concept in clinical practice to come to a diagnosis and treatment indication: mental health professionals working in gender-affirming medical care and transgender mental health care. Using a material semiotics approach, we reflect upon how Gender Dysphoria is done in clinical practice. Based on an analysis of seventeen practice-based interviews with clinicians as well as an examination of clinical guidelines and texts, we describe four modes in which Gender Dysphoria is ordered. These modes of ordering illustrate that Gender Dysphoria is not one, but multiple. We illustrate how in the mode of isolating, Gender Dysphoria is something which is carefully isolated from mental disorders, while in the modes doing the future and narrating, Gender Dysphoria is done as a continuous and predictable object of care. Such orderings of Gender Dysphoria potentially conflict with a fourth mode of ordering: the doing of diversity in transgender health care. The study's findings provide empirical insights into how transgender health care is currently done in The Netherlands and provide a foundation on which ethical debates on what good transgender health care should entail.

2.
Anal Bioanal Chem ; 414(19): 5755-5771, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35657388

RESUMO

Structural elucidation of lignin degradation products is a requirement for successfully developing lignin valorization technology. Most of mass spectrometry-based techniques have utilized negative ion mode mass spectrometry for structural elucidation of lignin-derived compounds. Unfortunately, simple deprotonation can lead to in-source fragmentation and may not be suitable for condensed lignin structures without acidic moieties. Herein, we present a lithium cationization methodology for mass spectrometry sequencing of advanced lignin oligomers having ß-ß' and ß-O-4' bonding motifs. To do so, two advanced lignin oligomers were first synthesized through a step-by-step synthetic route, and then subjected to two different ESI mass spectrometry techniques in positive ion mode using lithium cations for ionization. An orbitrap mass spectrometer was used to obtain exact mass information, and higher-energy collisional dissociation (HCD) was used to sequence the lignin model oligomers. Based on the sequence-specific fragment ions, sequence rules were proposed. Multi-stage (MSn) collision-induced dissociation (CID) using an ion trap mass spectrometer provided data to investigate the origin of each fragment ion and to further confirm proposed fragmentation pathways. In addition to ß-O-4' bond cleavage, the presented lithium cationization approach led to cleavage of ß-ß' bonds on the model oligomers in both ion trap and orbitrap mass spectrometry experiments. Additionally, MSn experiments were used to investigate possible lithium cationization sites on the model oligomers. Lithium cationization in positive ion mode mass spectrometry proved to be a robust tool for characterization and sequencing of advanced lignin oligomers with different bonding motifs.


Assuntos
Lignina , Espectrometria de Massas em Tandem , Íons , Lignina/química , Lítio , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos
3.
Biomed Chromatogr ; 36(1): e5243, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34519076

RESUMO

Sensitive, high-throughput methods for pharmacokinetic (PK) profiling are essential for potential therapeutics during critical stages of clinical trials. The application of a microfluidic capillary zone electrophoresis mass spectrometry (CZE-MS) method for PK profiling allows for rapid, sensitive and in-depth analysis of multiple samples within a short timeframe. Here, a CZE-MS approach for PK analysis was compared with a traditional UHPLC-MS approach when analyzing serum extracts from rats treated with a potential Alzheimer's disease therapeutic, BNC-1. Resulting PK data generated from both methods displayed statistical similarities. Additionally, the separation efficiency attributed to the use of the CZE-MS method provided substantial metabolic regulation data that was not apparent in the UHPLC-MS method. Additionally, the coupling of the CZE-MS method to the data processing software, MZmine2, was used to monitor changes in metabolism and observe putative BNC-1-derived metabolites. The ability to perform fast analyses without sacrificing sensitivity or metabolic information suggests that this CZE-MS method is ideal for metabolomics-inclusive, high-throughput PK profiling.


Assuntos
Eletroforese Capilar/métodos , Espectrometria de Massas/métodos , Naftiridinas/sangue , Doença de Alzheimer , Animais , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Masculino , Naftiridinas/química , Naftiridinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes
4.
BMC Med Ethics ; 23(1): 139, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36575401

RESUMO

BACKGROUND: In gender-affirming medical care (GAMC), ethical challenges in decision-making are ubiquitous. These challenges are becoming more pressing due to exponentially increasing referrals, politico-legal contestation, and divergent normative views regarding decisional roles and models. Little is known, however, about what ethical challenges related to decision-making healthcare professionals (HCPs) themselves face in their daily work in GAMC and how these relate to, for example, the subjective nature of Gender Incongruence (GI), the multidisciplinary character of GAMC and the role HCPs play in assessing GI and eligibility for interventions. Given the relevance and urgency of these questions, we conducted a qualitative study among HCPs providing GAMC to transgender adults in the Netherlands. METHODS: In this qualitative research, we conducted 11 semi-structured interviews between May 2020 and February 2021 with HCPs (six mental health professionals, two HCPs in endocrinology, two in plastic surgery, and one in nursing) working in two distinct GAMC settings. We purposively sampled for professional background and years of experience in GAMC. We analyzed our interview data using thematic analysis. As some respondents were more inclined to speak about what should or ought to be done to arrive at good or right decision-making, we identified both ethical challenges and norms. Furthermore, in our analysis, we differentiated between respondents' explicit and implicit ethical challenges and norms and ascertained the specific context in which these challenges emerged. RESULTS: Respondents' ethical challenges and norms centered on (1) dividing and defining decisional roles and bounds, (2) negotiating decision-making in a (multidisciplinary) team, and (3) navigating various decision-making temporalities. These themes arose in the context of uncertainties regarding (1) GAMC's guidelines, evidence, and outcomes, as well as (2) the boundaries and assessment of GI. CONCLUSIONS: This interview study provides detailed empirical insight into both the explicit and implicit ethical challenges that HCPs experience and their ethical norms regarding decision-making. It also describes how uncertainties and (implicit) normativities concerning GAMC and GI pre-structure the moral environment in which these challenges and norms manifest. We provide normative reflections and recommendations on handling these ethical challenges in a way that is sensitive to the context in which they arise.


Assuntos
Identidade de Gênero , Princípios Morais , Adulto , Humanos , Pesquisa Qualitativa , Incerteza , Atenção à Saúde , Tomada de Decisões
5.
Anal Bioanal Chem ; 413(15): 4037-4048, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33934193

RESUMO

Lignin and lignans are natural products found in plant cell walls. Lignin research has historically focused on lignin degradation techniques in the hope of converting lignin into useful aromatic carbon feedstocks. In contrast, investigations of lignans existing as natural product dimers, have been focused on thier interesting biological activities. Many lignan compounds are chemically identical to dimers derived from lignin, and both lignin and lignan dimers can possess multiple chiral centers leading to observations of diastereomer pairs where one diastereomer exhibits the bulk of the activity. For example, the G-(ß-O-4')-G dimer was reported to have a pro-angiogenic activity with one diastereomer of the pair showing enhanced pro-angiogenic activity. Traditional analytical techniques such as nuclear magnetic resonance (NMR) can differentiate the diastereomer pairs of ß-O-4 compounds; however, isolation of a pure sample is often required for analysis. This work was aimed at exploring the potential use of tandem mass spectrometry to differentiate diastereomer pairs in the ß-O-4 dimer series. Each diastereomer pair in the nine-dimer series was separated by HPLC and interrogated by tandem mass spectrometry. To understand the chromatographic behavior of the diastereomer pair in the ß-O-4 dimer series, three commercially available reverse phase HPLC columns were evaluated. A temperature programming experiment using water/acetonitrile isocratic elution showed that the chromatographic retention mechanism of these diastereomers was hydrophobically driven with analytes having more methoxy groups exhibiting larger ΔH0 and higher octanol-water partition coefficient values. Tandem mass spectrometry performed on each of the diastereomers produced fragment ions having different ion abundances. A mechanistic study based on the ion abundance of "sequence-specific ions" and "-48 ions" was used to assign a configuration to each of the pairs of diastereomers in the nine-dimer series.


Assuntos
Cromatografia/métodos , Lignina/química , Espectrometria de Massas em Tandem/métodos , Dimerização , Estereoisomerismo
6.
BMC Ophthalmol ; 21(1): 262, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34154547

RESUMO

BACKGROUND: Glaucomatous eyes often show strong intraocular pressure (IOP) fluctuations and individual measurements at different time points are necessary for personalized therapy. To survey IOP variations 48-hours diurnal and nocturnal IOP measurements were performed on two consecutive days. Aims of this study were to investigate the short-term repeatability of 48-hours measurements within one patient's IOP profile and long-term repeatability between two separate IOP profiles of the same patient. METHODS: A retrospective cohort study was performed evaluating data of 90 glaucoma patients in a German university medical center between 2006 and 2013. All patients underwent two separate diurnal IOP profiles of 48 h. IOP was measured at 8 am, 2 pm, 6 pm, 9 pm using Goldmann applanation tonometry and at 12 midnight using Perkins tonometry in supine position on two consecutive days. Intraclass correlation coefficients (ICC) were calculated to evaluate agreement for the same time points (each time point agreement) and for consecutive measurements within the IOP profiles (between time point agreement). ICC ≤ 0.4 was defined as poor agreement, 0.4-0.75 as moderate and ≥ 0.75 as excellent. Differences between time points were investigated by Bland Altman plots. RESULTS: Each time point measurements of profile 1 showed moderate to excellent agreement (ICCs 0.62-0.93). There was a moderate to excellent agreement for measurements between time points of profile 1 (ICCs day one 0.57-0.86, day two 0.71-0.90). Profile 2 was performed at a median interval of 12.0 months (quartiles 11.0 to 21.0). Each time point agreements within profile 2 showed ICCs from 0.23 to 0.81. It showed moderate to excellent agreement for changes between time points (ICCs 0.53-0.94). Day two demonstrated ICCs from 0.74 to 0.88. Long term IOP repeatability (over both pressure profiles) showed moderate to good agreement (ICCs 0.39-0.67). CONCLUSIONS: Short and long-term agreement of IOP measurements evaluated by diurnal IOP profiles is moderate to good. Due to mostly moderate agreements, which we believe represent IOP fluctuations, we conclude that it is necessary to perform 48-hours IOP profiles to gain a better overview of the individual IOP fluctuations.


Assuntos
Glaucoma , Pressão Intraocular , Ritmo Circadiano , Glaucoma/diagnóstico , Humanos , Manometria , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tonometria Ocular
7.
Med Health Care Philos ; 24(4): 687-699, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34008081

RESUMO

Over the past decades, great strides have been made to professionalize and increase access to transgender medicine. As the (biomedical) evidence base grows and conceptualizations regarding gender dysphoria/gender incongruence evolve, so too do ideas regarding what constitutes good treatment and decision-making in transgender healthcare. Against this background, differing care models arose, including the 'Standards of Care' and the so-called 'Informed Consent Model'. In these care models, ethical notions and principles such as 'decision-making' and 'autonomy' are often referred to, but left unsubstantiated. This not only transpires into the consultation room where stakeholders are confronted with many different ethical challenges in decision-making, but also hampers a more explicit discussion of what good decision-making in transgender medicine should be comprised of. The aim of this paper is to make explicit the conceptual and normative assumptions regarding decision-making and client autonomy underpinning the 'Standards of Care' and 'Informed Consent Model' currently used in transgender care. Furthermore, we illustrate how this elucidation aids in better understanding stakeholders' ethical challenges related to decision-making. Our ethical analysis lays bare how distinct normative ambiguities in both care models influence decision-making in practice and how foregrounding one normative model for decision-making is no moral panacea. We suggest that the first steps towards good decision-making in gender-affirming medical care are the acknowledgement of its inherent normative and moral dimensions and a shared, dialogical approach towards the decision-making process.


Assuntos
Pessoas Transgênero , Tomada de Decisões , Atenção à Saúde , Análise Ética , Humanos , Consentimento Livre e Esclarecido , Princípios Morais
8.
Electrophoresis ; 40(22): 2921-2928, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31475363

RESUMO

Application of a microfluidic CE* device for CZE-MS allows for fast, rapid, and in-depth analysis of large sample sets. This microfluidic CZE-MS device, the 908 Devices ZipChip, involves minimal sample preparation and is ideal for small cation analytes, such as alkaloids. Here, we evaluated the microfluidic device for the analysis of alkaloids from Lobelia cardinalis hairy root cultures. Extracts from wild-type, transgenic, and selected mutant plant cultures were analyzed and data batch processed using the mass spectral processing software MZmine2 and the statistical software Prism 8. In total 139 features were detected as baseline resolved peaks via the MZmine2 software optimized for the electrophoretic separations. Statistically significant differences in the relative abundance of the primary alkaloid lobinaline (C27 H34 N2 ), along with several putative "lobinaline-like" molecules were observed utilizing this approach. Additionally, a method for performing both targeted and untargeted MS/MS experiments using the microfluidic device was developed and evaluated. Coupling data-processing software with CZE-MS data acquisition has enabled comprehensive metabolomic profiles from plant cell cultures to be constructed within a single working day.


Assuntos
Alcaloides/análise , Eletroforese Capilar/métodos , Lobelia , Plantas Geneticamente Modificadas , Espectrometria de Massas em Tandem/métodos , Biologia Computacional , Limite de Detecção , Modelos Lineares , Lobelia/química , Lobelia/citologia , Técnicas Analíticas Microfluídicas/métodos , Células Vegetais/química , Extratos Vegetais/química , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/citologia , Reprodutibilidade dos Testes
9.
Strahlenther Onkol ; 195(2): 153-163, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30315483

RESUMO

OBJECTIVE: This study aimed to assess the reduction in dose to the penile bulb (PB) achieved by MRI-based contouring following drinking and endorectal balloon (ERB) instructions. PATIENTS AND METHODS: A total of 17 prostate cancer patients were treated with intensity-modulated radiation therapy (IMRT) and interstitial brachytherapy (IBT). CT and MRI datasets were acquired back-to-back based on a 65 cm3 air-filled ERB and drinking instructions. After rigid co-registration of the imaging data, the CT-based planning target volume (PTV) used for treatment planning was retrospectively compared to an MRI-based adaptive PTV and the dose to the PB was determined in each case. The adapted PTV encompassed a caudally cropped CT-based PTV which was defined on the basis of the MRI-based prostate contour plus an additional 5 mm safety margin. RESULTS: In the seven-field IMRT treatment plans, the MRI-based adapted PTV achieved mean (Dmean) and maximum (Dmax) doses to the PB which were significantly lower (by 7.6 Gy and 10.9 Gy, respectively; p <0.05) than those of the CT-contoured PTV. For 6 patients, the estimated PB Dmax (seven-field IMRT and IBT) for the adapted PTV was <70 Gy, whereas only 1 patient fulfilled this criterium with the CT-based PTV. CONCLUSION: MRI-based contouring and seven-field IMRT-based treatment planning achieved dose sparing to the PB. Whereas the comparison of MRI and CT contouring only relates to external beam radiotherapy (EBRT) sparing, considering EBRT and IBT shows the improvement in PB sparing for the total treatment.


Assuntos
Pênis/diagnóstico por imagem , Pênis/efeitos da radiação , Neoplasias da Próstata/radioterapia , Lesões por Radiação/prevenção & controle , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Idoso , Braquiterapia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Tomografia Computadorizada por Raios X
10.
Rapid Commun Mass Spectrom ; 33(8): 811-819, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30719787

RESUMO

RATIONALE: Effective analytical techniques are needed to characterize lignin products for the generation of renewable carbon sources. Application of matrix-assisted laser desorption/ionization (MALDI) in lignin analysis is limited because of poor ionization efficiency. In this study, we explored the potential of cationization along with a 2,5-dihydroxyacetophenone (DHAP) matrix to characterize model lignin oligomers. METHODS: Synthesized lignin oligomers were analyzed using the developed MALDI method. Two matrix systems, DHAP and α-cyano-4-hydroxycinnamic acid (CHCA), and three cations (lithium, sodium, silver) were evaluated using a Bruker UltraFlextreme time-of-flight mass spectrometer. Instrumental parameters, cation concentration, matrix, sample concentrations, and sample spotting protocols were optimized for improved results. RESULTS: The DHAP/Li+ combination was effective for dimer analysis as lithium adducts. Spectra from DHP and ferric chloride oligomers showed improved signal intensities up to decamers (m/z 1823 for the FeCl3 system) and provided insights into differences in the oligomerization mechanism. Spectra from a mixed DHP oligomer system containing H, G, and S units showed contributions from all monolignols within an oligomer level (e.g. tetramer level). CONCLUSIONS: The DHAP/Li+ method presented in this work shows promise to be an effective analytical tool for lignin analysis by MALDI and may provide a tool to assess lignin break-down efforts facilitating renewable products from lignin.

11.
BMC Ophthalmol ; 19(1): 197, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462225

RESUMO

BACKGROUND: Evaluation of clinical and functional results of a new extended depth of focus intraocular lens (EDOF-IOL). METHODS: Fourteen cataract patients (28 bilateral implantations) were assessed for uncorrected (UDVA) and corrected (CDVA) distance visual acuities; uncorrected (UNVA), distance-corrected (DCNVA) and best corrected (CNVA) near visual acuities; and uncorrected (UIVA) and distance-corrected (DCIVA) intermediate visual acuities - as well as binocular defocus curves. Photopic and mesopic contrast sensitivity was recorded. Reading acuity was evaluated using an electronic reading desk at fixed distances and at the patient's preferred near and intermediate distances. Visual symptoms were assessed with a halo and glare simulator plus a patient questionnaire which also recorded quality of life. RESULTS: Median postoperative monocular UDVA was 0.13logMAR (range - 0.08 to 0.42logMAR), median CDVA was - 0.01logMAR (range - 0.20 to 0.22logMAR), median UIVA at 80 cm was - 0.05logMAR (range - 0.18 to 0.58logMAR) and median UNVA at 40 cm was 0.14logMAR (range - 0.10 to 0.64logMAR). Binocular uncorrected reading acuity was 0.10logMAR at 40 cm and 0.11logMAR at 80 cm. Patients preferred a median intermediate reading distance of 62.8 cm over the predetermined 80 cm, which allowed them to read smaller letter size but did not improve reading acuity. Patients reported a high rate of spectacle independence and satisfaction in everyday life and little to no dysphotopsia. CONCLUSION: The Mini WELL Ready IOL provided good postoperative functional results at far and intermediate distances and improved the visual and reading acuity at reading distance. The lens caused little to no dysphotopsia. TRIAL REGISTRATION: The study protocol was registered at the German Clinical Trials Register: DRKS00007837 (Registered Date: March 9th, 2015).


Assuntos
Percepção de Profundidade/fisiologia , Lentes Intraoculares , Facoemulsificação , Pseudofacia/fisiopatologia , Refração Ocular/fisiologia , Acuidade Visual/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Ofuscação , Humanos , Implante de Lente Intraocular , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese , Leitura , Visão Binocular/fisiologia
12.
Arch Sex Behav ; 47(8): 2319-2333, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30229517

RESUMO

Treatment teams providing transgender-affirming medical care are inherently faced with various kinds of moral and ethical dilemmas and questions, which are becoming even more pressing due to increasing treatment numbers and public attention for transgender care. Little is known about what kinds of moral and ethical challenges manifest in clinical practice. The aim of the present research was to map the moral and ethical challenges of healthcare professionals working in a specialized multidisciplinary transgender care center. Over a period of 7 months, during a focused ethnographic study, data were collected through participant observation of multidisciplinary team meetings, observation of individual psychodiagnostic assessment sessions with clients, and analysis of transcripts and reports of a series of moral case deliberations. A thematic content analysis of the data identified various implicit and explicit moral and ethical challenges around the following six themes: (1) assessing eligibility; (2) content of treatment; (3) sequential order of the treatment steps; (4) role of the clinical guidelines; (5) differing notions regarding gender identity, and (6) decision-making process. Our research provides a detailed insight into the way healthcare professionals experience these moral and ethical challenges and how they are related to (local) guidelines, the multidisciplinary character of GD care, and its inherent implicit and explicit gender norms. Our findings suggest that good transgender care may profit from continuous multidisciplinary deliberation of and sensitivity toward the normative dimension of transgender care. The paper ends with recommendations for ethics support mechanisms in transgender care.


Assuntos
Atenção à Saúde/ética , Disforia de Gênero/terapia , Pessoal de Saúde/psicologia , Princípios Morais , Transexualidade/terapia , Antropologia Cultural , Atitude do Pessoal de Saúde , Tomada de Decisões , Definição da Elegibilidade , Feminino , Disforia de Gênero/diagnóstico , Identidade de Gênero , Humanos , Comunicação Interdisciplinar , Masculino , Papel do Médico , Guias de Prática Clínica como Assunto , Pesquisa Qualitativa , Pessoas Transgênero
13.
Brain Inj ; 32(3): 363-380, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29283288

RESUMO

BACKGROUND: Although elevated serum levels of visinin-like protein 1 (VILIP-1), a neuron-specific calcium sensor protein, are associated with ischaemic stroke, only a single study has evaluated VILIP-1 as a biomarker of traumatic brain injury (TBI). The current proof-of-concept study was designed to determine whether serum VILIP-1 levels increase post-injury in a well-characterized rat unilateral cortical contusion model. METHODS: Lateral flow devices (LFDs) rapidly (< 20 min) detected trace serum levels (pg/mL) of VILIP-1 in a small input sample volume (10 µL). Temporal profiles of serum levels at baseline and post-injury were measured in male Sprague Dawley rats subjected to very mild-, mild unilateral-cortical contusion, or naïve surgery and in male Sprague Dawley rats following a diffuse TBI or sham surgery. RESULTS: Mean serum levels were significantly elevated by 0.5 h post-injury and remained so throughout the temporal profile compared with baseline in very mild and mild unilateral contusions but not in naïve surgeries. Serum levels were also elevated in a small cohort of animals subjected to a diffuse TBI injury. CONCLUSIONS: Overall, the current study demonstrates that the novel LFD is a reliable and rapid point-of-care diagnostic for the detection and quantification of serum levels of UB-VILIP-1 in a clinically relevant time frame.


Assuntos
Lesões Encefálicas/sangue , Lesões Encefálicas/diagnóstico , Neurocalcina/sangue , Animais , Córtex Cerebral/lesões , Estudos de Coortes , Modelos Animais de Doenças , Células HEK293 , Humanos , Imunoprecipitação , Modelos Lineares , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Ubiquitina/metabolismo
14.
Analyst ; 142(17): 3241-3249, 2017 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-28795694

RESUMO

Electrospray ionization mass spectrometry ESI-MS is a powerful technique for the characterization of macromolecules and their noncovalent binding with guest ions. We herein evaluate the feasibility of using ESI-MS as a screening tool for predicting potentiometric selectivities of ionophores. Ion-selective electrodes based on the cyclic peptide, cyclosporin A, were developed, and their potentiometric selectivity pattern was evaluated. Optimized electrodes demonstrated near-Nernstian slopes with micromolar detection limits toward calcium. ESI-MS and ESI-MS/MS were employed to determine the relative association strengths of cyclosporin A with various cations. The observed MS intensities of ion-ionophore complexes correlate favorably with the potentiometric selectivity pattern that was demonstrated by cyclosporin-based electrodes. This correlation was found to hold true for other established ionophores, such as valinomycin and benzo-18-crown-6. Taken together, these experiments demonstrate that mass spectrometry could be used to predict the selectivity patterns of new ionophores for potentiometric and optical ion sensors. Further, this approach could be useful in screening mixtures or libraries of newly-synthesized compounds to identify selective ionophores.

16.
BMC Ophthalmol ; 17(1): 150, 2017 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-28830376

RESUMO

BACKGROUND: Laboratory analysis and optical quality assessment of explanted hydrophilic intraocular lenses (IOLs) with clinically significant opacification after posterior lamellar keratoplasty (DMEK and DSAEK). METHODS: Thirteen opacified IOLs after posterior lamellar keratoplasty, 8 after descemet stripping automated endothelial keratoplasty (DSAEK), 3 after descemet membrane endothelial keratoplasty (DMEK) and 2 after both DSAEK and DMEK were analysed in our laboratory. Analyses included optical bench assessment for optical quality, light microscopy, scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDS). RESULTS: In all IOLs the opacification was caused by a thin layer of calciumphosphate that had accumulated underneath the anterior optical surface of the IOLs in the area spared by the pupil/anterior capsulorhexis. The calcifications lead to a significant deterioration of the modulation transfer function across all spatial frequencies of the affected IOLs. CONCLUSIONS: The instillation of exogenous material such as air or gas into the anterior chamber increases the risk for opacification of hydrophilic IOLs irrespective of the manufacturer or the exact composition of the hydrophilic lens material. It is recommended to avoid the use of hydrophilic acrylic IOLs in patients with endothelial dystrophy that will likely require procedures involving the intracameral instillation of air or gas, such as DMEK or DS(A)EK.


Assuntos
Catarata/etiologia , Transplante de Córnea/efeitos adversos , Lentes Intraoculares , Complicações Pós-Operatórias/etiologia , Idoso , Idoso de 80 Anos ou mais , Transplante de Córnea/métodos , Feminino , Humanos , Masculino , Microscopia/métodos , Pessoa de Meia-Idade , Óptica e Fotônica
17.
Strahlenther Onkol ; 192(11): 806-814, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27402389

RESUMO

BACKGROUND AND PURPOSE: Small animal irradiation systems were developed for preclinical evaluation of tumor therapy closely resembling the clinical situation. Mostly only clinical LINACs are available, so protocols for small animal partial body irradiation using a conventional clinical system are essential. This study defines a protocol for conformal brain tumor irradiations in mice. MATERIALS AND METHODS: CT and MRI images were used to demarcate the target volume and organs at risk. Three 6 MV photon beams were planned for a total dose of 10 fractions of 1.8 Gy. The mouse position in a dedicated applicator was verified by an X­ray patient positioning system before each irradiation. Dosimetric verifications (using ionization chambers and films) were performed. Irradiation-induced DNA damage was analyzed to verify the treatment effects on the cellular level. RESULTS: The defined treatment protocol and the applied fractionation scheme were feasible. The in-house developed applicator was suitable for individual positioning at submillimeter accuracy of anesthetized mice during irradiation, altogether performed in less than 10 min. All mice tolerated the treatment well. Measured dose values perfectly matched the nominal values from treatment planning. Cellular response was restricted to the target volume. CONCLUSION: Clinical LINAC-based irradiations of mice offer the potential to treat orthotopic tumors conformably. Especially with respect to lateral penumbra, dedicated small animal irradiation systems exceed the clinical LINAC solution.


Assuntos
Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/veterinária , Posicionamento do Paciente/veterinária , Radiocirurgia/veterinária , Planejamento da Radioterapia Assistida por Computador/veterinária , Radioterapia Guiada por Imagem/veterinária , Animais , Neoplasias Encefálicas/diagnóstico por imagem , Linhagem Celular Tumoral , Camundongos , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resultado do Tratamento
18.
J Neurochem ; 128(2): 294-304, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24032632

RESUMO

Studies of oxidative damage during the progression of Alzheimer's disease (AD) suggest its central role in disease pathogenesis. To investigate levels of nucleic acid oxidation in both early and late stages of AD, levels of multiple base adducts were quantified in nuclear and mitochondrial DNA from the superior and middle temporal gyri (SMTG), inferior parietal lobule (IPL), and cerebellum (CER) of age-matched normal control subjects, subjects with mild cognitive impairment, preclinical AD, late-stage AD, and non-AD neurological disorders (diseased control; DC) using gas chromatography/mass spectrometry. Median levels of multiple DNA adducts in nuclear and mitochondrial DNA were significantly (p ≤ 0.05) elevated in the SMTG, IPL, and CER in multiple stages of AD and in DC subjects. Elevated levels of fapyguanine and fapyadenine in mitochondrial DNA suggest a hypoxic environment early in the progression of AD and in DC subjects. Overall, these data suggest that oxidative damage is an early event not only in the pathogenesis of AD but is also present in neurodegenerative diseases in general. Levels of oxidized nucleic acids in nDNA and mtDNA were found to be significantly elevated in mild cognitive impairment (MCI), preclinical Alzheimer's disease (PCAD), late-stage AD (LAD), and a pooled diseased control group (DC) of frontotemporal dementia (FTD) and dementia with Lewy bodies (DLB) subjects compared to normal control (NC) subjects. Nucleic acid oxidation peaked early in disease progression and remained elevated. The study suggests nucleic acid oxidation is a general event in neurodegeneration.


Assuntos
Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , DNA/metabolismo , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Núcleo Celular/genética , Núcleo Celular/metabolismo , Adutos de DNA/metabolismo , Dano ao DNA , DNA Mitocondrial/metabolismo , Feminino , Demência Frontotemporal/metabolismo , Humanos , Doença por Corpos de Lewy/metabolismo , Masculino , Oxirredução
19.
Endoscopy ; 46(1): 46-52, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24218308

RESUMO

BACKGROUND AND STUDY AIMS: This study aimed to reassess whether the Forrest classification is still useful for the prediction of rebleeding and mortality in peptic ulcer bleedings and, based on this, whether the classification could be simplified. PATIENTS AND METHODS: Prospective registry data on peptic ulcer bleedings were collected and categorized according to the Forrest classification. The primary outcomes were 30-day rebleeding and all-cause mortality rates. Receiver operating characteristic curves were used to test whether simplification of the Forrest classification into high risk (Forrest Ia), increased risk (Forrest Ib-IIc), and low risk (Forrest III) classes could be an alternative to the original classification. RESULTS: In total, 397 patients were included, with 18 bleedings (4.5%) being classified as Forrest Ia, 73 (18.4%) as Forrest Ib, 86 (21.7%) as Forrest IIa, 32 (8.1%) as Forrest IIb, 59 (14.9%) as Forrest IIc, and 129 (32.5%) as Forrest III. Rebleeding occurred in 74 patients (18.6%). Rebleeding rates were highest in Forrest Ia peptic ulcers (59%). The odds ratios for rebleeding among Forrest Ib-IIc ulcers were similar. In subgroup analysis, predicting rebleeding using the Forrest classification was more reliable for gastric ulcers than for duodenal ulcers. The simplified Forrest classification had similar test characteristics to the original Forrest classification. CONCLUSION: The Forrest classification still has predictive value for rebleeding of peptic ulcers, especially for gastric ulcers; however, it does not predict mortality. Based on these results, a simplified Forrest classification is proposed. However, further studies are needed to validate these findings.


Assuntos
Úlcera Duodenal/classificação , Úlcera Péptica Hemorrágica/classificação , Úlcera Gástrica/classificação , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Úlcera Duodenal/complicações , Feminino , Hemostase Endoscópica , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica Hemorrágica/mortalidade , Úlcera Péptica Hemorrágica/terapia , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Recidiva , Medição de Risco , Úlcera Gástrica/complicações
20.
Eur Radiol ; 24(3): 638-48, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24158528

RESUMO

OBJECTIVE: To compare the diagnostic accuracy of TE and MRE and establish cutoff levels and diagnostic strategies for both techniques, enabling selection of patients for liver biopsy. METHODS: One hundred three patients with chronic hepatitis B or C and liver biopsy were prospectively included. Areas under curves (AUROC) were compared for TE and MRE for METAVIR fibrosis grade ≥ F2 and ≥F3. We defined cutoff values for selection of patients with F0-F1 (sensitivity >95%) and for significant fibrosis F2-F4 (specificity >95%). RESULTS: Following exclusions, 85 patients were analysed (65 CHB, 19 CHC, 1 co-infected). Fibrosis stages were F0 (n = 3), F1 (n = 53), F2 (n = 15), F3 (n = 8) and F4 (n = 6). TE and MRE accuracy were comparable [AUROCTE ≥ F2: 0.914 (95% CI: 0.857-0.972) vs. AUROCMRE ≥ F2: 0.909 (0.840-0.977), P = 0.89; AUROCTE ≥ F3: 0.895 (0.816-0.974) vs. AUROCMRE ≥ F3: 0.928 (0.874-0.982), P = 0.42]. Cutoff values of <5.2 and ≥8.9 kPa (TE) and <1.66 and ≥2.18 kPa (MRE) diagnosed 64% and 66% of patients correctly as F0-F1 or F2-F4. A conditional strategy in inconclusive test results increased diagnostic yield to 80%. CONCLUSION: TE and MRE have comparable accuracy for detecting significant fibrosis, which was reliably detected or excluded in two-thirds of patients. A conditional strategy further increased diagnostic yield to 80%. KEY POINTS: • Both ultrasound-based transient elastography and magnetic resonance elastography can assess hepatic fibrosis. • Both have comparable accuracy for detecting liver fibrosis in viral hepatitis. • The individual techniques reliably detect or exclude significant liver fibrosis in 66 %. • A conditional strategy for inconclusive findings increases the number of correct diagnoses.


Assuntos
Hepatite B Crônica/diagnóstico por imagem , Hepatite B Crônica/patologia , Hepatite C Crônica/diagnóstico por imagem , Hepatite C Crônica/patologia , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/patologia , Adulto , Área Sob a Curva , Biópsia , Técnicas de Imagem por Elasticidade/métodos , Feminino , Hepatite B Crônica/complicações , Hepatite C Crônica/complicações , Humanos , Cirrose Hepática/etiologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Adulto Jovem
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