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1.
BMC Med Ethics ; 24(1): 25, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-37004054

RESUMO

The overarching aim of this article is to scrutinize how severity can work as a qualifier for the moral impetus of malady. While there is agreement that malady is of negative value, there is disagreement about precisely how this is so. Nevertheless, alleviating disease, injury, and associated suffering is almost universally considered good. Furthermore, the strength of a diseased person's moral claims for our attention and efforts will inevitably vary. This article starts by reflecting on what kind of moral impetus malady incites. We then analyze how severity may qualify this impetus. We do so by discussing the relationship between severity and need, well-being and disvalue, death, urgency, rule of rescue, and distributive justice. We then summarize our thoughts about severity as a moral qualifier. We conclude that severity is, and should continue to be seen, as a morally significant concept that deserves continued attention in the future.


Assuntos
Princípios Morais , Justiça Social , Humanos , Dissidências e Disputas
2.
Angiogenesis ; 25(1): 35-45, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34905124

RESUMO

Angiogenesis describes the formation of new blood vessels from pre-existing vascular structures. While the most studied mode of angiogenesis is vascular sprouting, specific conditions or organs favor intussusception, i.e., the division or splitting of an existing vessel, as preferential mode of new vessel formation. In the present study, sustained (33-h) intravital microscopy of the vasculature in the chick chorioallantoic membrane (CAM) led to the hypothesis of a novel non-sprouting mode for vessel generation, which we termed "coalescent angiogenesis." In this process, preferential flow pathways evolve from isotropic capillary meshes enclosing tissue islands. These preferential flow pathways progressively enlarge by coalescence of capillaries and elimination of internal tissue pillars, in a process that is the reverse of intussusception. Concomitantly, less perfused segments regress. In this way, an initially mesh-like capillary network is remodeled into a tree structure, while conserving vascular wall components and maintaining blood flow. Coalescent angiogenesis, thus, describes the remodeling of an initial, hemodynamically inefficient mesh structure, into a hierarchical tree structure that provides efficient convective transport, allowing for the rapid expansion of the vasculature with maintained blood supply and function during development.


Assuntos
Membrana Corioalantoide , Neovascularização Fisiológica , Animais , Capilares , Morfogênese , Neovascularização Patológica
3.
Sportverletz Sportschaden ; 32(3): 171-186, 2018 08.
Artigo em Alemão | MEDLINE | ID: mdl-30176692

RESUMO

A rupture of the anterior cruciate ligament (ACL) represents a severe injury in game sports, which is time and cost-intensive for athletes and clubs alike. As the lower extremities are subjected to multiple forms of strain and high demands are placed on them, athletes in games like soccer are affected more often than others. The point of return-to-play after such severe injuries is often preceded by long periods of rehabilitation. However, these periods often vary strongly. Multiple approaches are being discussed to estimate the point of return-to-play using functional test procedures. However, no general consensus has been reached regarding the relevant parameters, available test procedures and interpretation of test results. Based on the requirement profile of soccer as a game sport, this review evaluates functional tests regarding the requirements strength, speed, agility, and movement quality as a coordinative feature. In addition to tests regarding individual forms of strain, this review also discusses combined test protocols. It describes performance variants and scientific quality criteria as well as the potential for practical implementation. While jumps can detect side-to-side asymmetries only through additional equipment such as force plates or markers, hop tests are more suitable for implementation and allow for an easier assessment of side-to-side asymmetries. Although several combined test protocols exist, none of them measures the entire requirement profile for games sports. To decrease the number of re-injuries after ACL rupture, a combined test protocol with a selection of the described scientifically reliable functional tests should be created and implemented as a return-to-competition guideline as well as pre-injury screening prior and during the season.


Assuntos
Lesões do Ligamento Cruzado Anterior/reabilitação , Traumatismos em Atletas/reabilitação , Volta ao Esporte , Teste de Esforço , Humanos , Força Muscular , Recuperação de Função Fisiológica , Futebol/lesões
4.
Int J Mol Med ; 42(1): 534-546, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29693115

RESUMO

Photodynamic therapy (PDT) has emerged as an effective and minimally invasive cancer treatment modality. In the present study, two novel phthalocyanines, tetra­triethyleneoxysulfonyl substituted zinc phthalocyanine (ZnPc) and dihydroxy­2,9(10),16(17),23(24)­tetrakis(4,7,10­trioxaundecan­1­sulfonyl) silicon phthalocyanine (Pc32), were investigated as photosensitizers (PS) for PDT of cholangiocarcinoma (CC). ZnPc showed a pronounced dose­dependent and predominantly cytoplasmic accumulation in EGI­1 and TFK­1 CC cell lines. Pc32 also accumulated in the CC cells, but this was less pronounced. Without photoactivation, the PS did not exhibit any antiproliferative or cytotoxic effects. Upon photoactivation, ZnPc induced the formation of reactive oxygen species (ROS) and immediate phototoxicity, leading to a dose­dependent decrease in cell proliferation, and an induction of mitochondria­driven apoptosis and cell cycle arrest of EGI­1 and TFK­1 cells. Although photoactivated Pc32 also induced ROS formation in the two cell lines, the extent was less marked, compared with that induced by ZnPc­PDT, and pronounced antipoliferative effects occurred only in the less differentiated EGI­1 cells, whereas the more differentiated TFK­1 cells did not show sustained growth inhibition upon Pc32­PDT induction. In vivo examinations on the antiangiogenic potency of the novel PS were performed using chorioallantoic membrane (CAM) assays, which revealed reduced angiogenic sprouting with a concomitant increase in nonperfused regions and degeneration of the vascular network of the CAM following induction with ZnPc­PDT only. The study demonstrated the pronounced antiproliferative and antiangiogenic potency of ZnPc as a novel PS for PDT, meriting further elucidation as a promising PS for the photodynamic treatment of CC.


Assuntos
Colangiocarcinoma/tratamento farmacológico , Indóis/uso terapêutico , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Silício/uso terapêutico , Zinco/uso terapêutico , Inibidores da Angiogênese/farmacologia , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Galinhas , Colangiocarcinoma/patologia , Membrana Corioalantoide/efeitos dos fármacos , Membrana Corioalantoide/metabolismo , Humanos , Indóis/farmacologia , Isoindóis , Fármacos Fotossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Silício/farmacologia , Zinco/farmacologia
5.
Mol Cancer Ther ; 16(11): 2364-2374, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28838999

RESUMO

Novel approaches for the medical treatment of advanced solid tumors, including testicular germ cell tumors (TGCT), are desperately needed. Especially, TGCT patients not responding to cisplatin-based therapy need therapeutic alternatives, as there is no effective medical treatment available for this particular subgroup. Here, we studied the suitability of the novel dual-mode compound animacroxam for TGCT treatment. Animacroxam consists of an HDAC-inhibitory hydroxamate moiety coupled to a 4,5-diarylimidazole with inherent cytoskeleton disrupting potency. Animacroxam revealed pronounced antiproliferative, cell-cycle arresting, and apoptosis-inducing effects in TGCT cell lines with different cisplatin sensitivities. The IC50 values of animacroxam ranged from 0.22 to 0.42 µmol/L and were not correlated to the cisplatin sensitivity of the tumor cells. No unspecific cytotoxicity of animacroxam was observed in either cisplatin-sensitive or resistant TGCT cells, even at doses as high as 10 µmol/L. Furthermore, animacroxam induced the formation of actin stress fibers in cancer cells, thereby confirming the cytoskeleton-disrupting and antimigratory properties of its imidazole moiety. When compared with the clinically established HDAC inhibitor vorinostat, the novel dual-mode compound animacroxam exhibited superior antitumoral efficacy in vitro Animacroxam also reduced the tumor size of TGCT tumors in vivo, as evidenced by performing xenograft experiments on tumor bearing chorioallantoic membranes of fertilizes chicken eggs (CAM assay). The in vivo experiments also revealed a very good tolerability of the compound, and hence, animacroxam may be a promising candidate for innovative treatment of TGCT in general and the more so for platinum-insensitive or refractory TGCT. Mol Cancer Ther; 16(11); 2364-74. ©2017 AACR.


Assuntos
Cinamatos/administração & dosagem , Citoesqueleto/efeitos dos fármacos , Inibidores de Histona Desacetilases/administração & dosagem , Imidazóis/administração & dosagem , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Neoplasias Testiculares/tratamento farmacológico , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cinamatos/química , Cisplatino/administração & dosagem , Resistencia a Medicamentos Antineoplásicos/genética , Histona Desacetilases/genética , Humanos , Imidazóis/química , Camundongos , Neoplasias Embrionárias de Células Germinativas/genética , Neoplasias Embrionárias de Células Germinativas/patologia , Neoplasias Testiculares/genética , Neoplasias Testiculares/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Sci Rep ; 7: 42307, 2017 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-28195140

RESUMO

Multiexcitonic transitions and emission of several photons per excitation comprise a very attractive feature of semiconductor quantum dots for optoelectronics applications. However, these higher-order radiative processes are usually quenched in colloidal quantum dots by Auger and other nonradiative decay channels. To increase the multiexcitonic quantum efficiency, several groups have explored plasmonic enhancement, so far with moderate results. By controlled positioning of individual quantum dots in the near field of gold nanocone antennas, we enhance the radiative decay rates of monoexcitons and biexcitons by 109 and 100 folds at quantum efficiencies of 60 and 70%, respectively, in very good agreement with the outcome of numerical calculations. We discuss the implications of our work for future fundamental and applied research in nano-optics.

7.
Small ; 13(3)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28084694

RESUMO

Osteocytes-the central regulators of bone remodeling-are enclosed in a network of microcavities (lacunae) and nanocanals (canaliculi) pervading the mineralized bone. In a hitherto obscure process related to aging and disease, local plugs in the lacuno-canalicular network disrupt cellular communication and impede bone homeostasis. By utilizing a suite of high-resolution imaging and physics-based techniques, it is shown here that the local plugs develop by accumulation and fusion of calcified nanospherites in lacunae and canaliculi (micropetrosis). Two distinctive nanospherites phenotypes are found to originate from different osteocytic elements. A substantial deviation in the spherites' composition in comparison to mineralized bone further suggests a mineralization process unlike regular bone mineralization. Clearly, mineralization of osteocyte lacunae qualifies as a strong marker for degrading bone material quality in skeletal aging. The understanding of micropetrosis may guide future therapeutics toward preserving osteocyte viability to maintain mechanical competence and fracture resistance of bone in elderly individuals.


Assuntos
Envelhecimento/patologia , Osso e Ossos/patologia , Calcificação Fisiológica , Nanosferas/química , Osteopetrose/patologia , Idoso de 80 Anos ou mais , Matriz Óssea/ultraestrutura , Feminino , Humanos , Nanosferas/ultraestrutura , Osteócitos/ultraestrutura
8.
Int J Oncol ; 50(3): 953-963, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28098886

RESUMO

Photodynamic therapy (PDT) has gathered much attention in the field of cancer treatment and is increasingly used as an alternative solution for esophageal cancer therapy. However, there is a constant need for improving the effectiveness and tolerability of the applied photosensitizers (PS). Here, we propose tetra-triethyleneoxysulfonyl substituted zinc phthalocyanine (ZnPc) as a promising PS for photodynamic treatment of esophageal cancer. ZnPc-induced phototoxicity was studied in two human esophageal cancer cell lines: OE-33 (adenocarcinoma) and Kyse-140 (squamous cell carcinoma). In vitro studies focused on the uptake and intracellular distribution of the novel ZnPc as well as on its growth inhibitory potential, reactive oxygen species (ROS) formation and the induction of apoptosis. The chicken chorioallantoic membrane assay (CAM assay) and studies on native Wistar rats were employed to determine the antineoplastic and antiangiogenic activity of ZnPc-PDT as well as the tolerability and safety of non-photoactivated ZnPc in vivo. ZnPc was taken up by cancer cells in a dose- and time-dependent manner and showed a homogeneous cytoplasmic distribution. Photoactivation of ZnPc-loaded (1-10 µM) cells led to a dose-dependent growth inhibition of esophageal adenocarcinoma and squamous cell carcinoma cells of >90%. The antiproliferative effect was based on ROS-induced cytotoxicity and the induction of mitochondria-driven apoptosis. In vivo studies on esophageal tumor plaques grown on the CAM revealed pronounced antiangiogenic and antineoplastic effects. ZnPc-PDT caused long-lasting changes in the vascular architecture and a marked reduction of tumor feeding blood vessels. Animal studies confirmed the good tolerability and systemic safety of ZnPc, as no changes in immunological, behavioral and organic parameters could be detected upon treatment with the non-photoactivated ZnPc. Our findings show the extraordinary photoactive potential of the novel ZnPc as a photosensitizer for PDT of esophageal cancer.


Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Neoplasias Esofágicas/terapia , Indóis/farmacologia , Compostos Organometálicos/farmacologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/farmacocinética , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Membrana Corioalantoide/efeitos dos fármacos , Humanos , Indóis/efeitos adversos , Indóis/farmacocinética , Isoindóis , Compostos Organometálicos/efeitos adversos , Compostos Organometálicos/farmacocinética , Fármacos Fotossensibilizantes/efeitos adversos , Fármacos Fotossensibilizantes/farmacocinética , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Compostos de Zinco
9.
Microcirculation ; 24(4)2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28075525

RESUMO

OBJECTIVE: After arteriolar occlusion, collaterals enlarge and initially elevated WSS normalizes. While most previous studies focused on endpoints of such adaptive changes in larger collaterals, the present investigation aimed to continuously determine the relation between WSS and diameter in microvascular collaterals during adaptive reactions. METHODS: In Hamburger-Hamilton stage 40 CAMs, junction points between arteriolar segments were identified and the third upstream segment on one side was occluded. Intravital microscopy recordings were taken for 24 hours post-occlusion. Segment diameter and blood velocity were measured: WSS and capillary density were calculated. RESULTS: After occlusion, vascular diameters exhibited an immediate decrease, then increased with a time constant of 2.5 ± 0.8 hours and reached a plateau of up to 60% above baseline after about 7 hours. Vascular tone showed no significant change. WSS exhibited an immediate increase post-occlusion and linearly returned to baseline after about 12 hours. Local WSS change and diameter change rate showed similar patterns during the initial but not the later phase of post-occlusive adaptation. CONCLUSIONS: CAM collaterals undergo fast structural remodeling within 24 hours post-occlusion. This remodeling might be driven by local WSS and by other regulators within the vascular network.


Assuntos
Arteriopatias Oclusivas/fisiopatologia , Arteríolas/fisiopatologia , Membrana Corioalantoide/irrigação sanguínea , Circulação Colateral , Remodelação Vascular , Doença Aguda , Animais , Embrião de Galinha , Microscopia Intravital , Estresse Mecânico , Fatores de Tempo
10.
Am J Physiol Heart Circ Physiol ; 311(4): H913-H926, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27402670

RESUMO

The chick chorioallantoic membrane (CAM) is extensively used as an in vivo model. Here, structure and hemodynamics of CAM vessel trees were analyzed and compared with predictions of Murray's law. CAM microvascular networks of Hamburger-Hamilton stage 40 chick embryos were scanned by videomicroscopy. Three networks with ∼3,800, 580, and 480 segments were digitally reconstructed, neglecting the capillary mesh. Vessel diameters (D) and segment lengths were measured, and generation numbers and junctional exponents at bifurcations were derived. In selected vessels, flow velocities (v) and hematocrit were measured. Hemodynamic simulations, incorporating the branching of capillaries from preterminal vessels, were used to estimate v, volume flow, shear stress (τ), and pressure for all segments of the largest network. For individual arteriovenous flow pathways, terminal arterial and venous generation numbers are negatively correlated, leading to low variability of total topological and morphological pathway lengths. Arteriolar velocity is proportional to diameter (v∝D1.03 measured, v∝D0.93 modeling), giving nearly uniform τ levels (τ∝D0.05). Venular trees exhibit slightly higher exponents (v∝D1.3, τ∝D0.38). Junctional exponents at divergent and convergent bifurcations were 2.05 ± 1.13 and 1.97 ± 0.95 (mean ± SD) in contrast to the value 3 predicted by Murray's law. In accordance with Murray's law, τ levels are (nearly) maintained in CAM arterial (venular) trees, suggesting vascular adaptation to shear stress. Arterial and venous trees show an interdigitating arrangement providing homogeneous flow pathway properties and have preterminal capillary branches. These properties may facilitate efficient oxygen exchange in the CAM during rapid embryonic growth.


Assuntos
Artérias/fisiologia , Arteríolas/fisiologia , Capilares/fisiologia , Membrana Corioalantoide/irrigação sanguínea , Hemodinâmica , Animais , Artérias/anatomia & histologia , Arteríolas/anatomia & histologia , Velocidade do Fluxo Sanguíneo , Capilares/anatomia & histologia , Embrião de Galinha , Simulação por Computador , Hematócrito , Modelos Cardiovasculares , Estresse Mecânico
11.
Nano Lett ; 16(6): 3524-32, 2016 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-27124605

RESUMO

The monolithic integration of wurtzite GaN on Si via metal-organic vapor phase epitaxy is strongly hampered by lattice and thermal mismatch as well as meltback etching. This study presents single-layer graphene as an atomically thin buffer layer for c-axis-oriented growth of vertically aligned GaN nanorods mediated by nanometer-sized AlGaN nucleation islands. Nanostructures of similar morphology are demonstrated on graphene-covered Si(111) as well as Si(100). High crystal and optical quality of the nanorods are evidenced through scanning transmission electron microscopy, micro-Raman, and cathodoluminescence measurements supported by finite-difference time-domain simulations. Current-voltage characteristics revealed high vertical conduction of the as-grown GaN nanorods through the Si substrates. These findings are substantial to advance the integration of GaN-based devices on any substrates of choice that sustains the GaN growth temperatures, thereby permitting novel designs of GaN-based heterojunction device concepts.

12.
Photodiagnosis Photodyn Ther ; 13: 148-157, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26162500

RESUMO

Photodynamic therapy (PDT) has emerged as an effective and minimally invasive treatment option for several diseases, including some forms of cancer. However, several drawbacks of the approved photosensitizers (PS), such as insufficient light absorption at therapeutically relevant wavelengths hampered the clinical effectiveness of PDT. Phthalocyanines (Pc) are interesting PS-candidates with a strong light absorption in the favourable red spectral region and a high quantum yield of cancer cell destroying singlet oxygen generation. Here, we evaluated the suitability of tetra-triethyleneoxysulfonyl substituted zinc phthalocyanine (ZnPc) as novel PS for PDT. ZnPc-induced phototoxicity, induction of apoptosis as well as cell cycle arresting effects was studied in the human gastrointestinal cancer cell lines of different origin. Photoactivation of ZnPc-pretreated (1-10 µM) cancer cells was achieved by illumination with a broad band white light source (400-700 nm) at a power density of 10 J/cm(2). Photoactivation of ZnPc-loaded cells revealed strong phototoxic effects, leading to a dose-dependent decrease of cancer cell proliferation of up to almost 100%, the induction of apoptosis and a G1-phase arrest of the cell cycle, which was associated with decrease in cyclin D1 expression. By contrast, ZnPc-treatment without illumination did not induce any cytotoxicity, apoptosis, cell cycle arrest or decreased cell growth. Antiangiogenic effects of ZnPc-PDT were investigated in vivo by performing CAM assays, which revealed a marked degradation of blood vessels and the capillary plexus of the chorioallantoic membrane of fertilized chicken eggs. Based on our data we think that ZnPc may be a promising novel photosensitizer for innovative PDT.


Assuntos
Indóis/administração & dosagem , Indóis/síntese química , Neoplasias Experimentais/tratamento farmacológico , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/síntese química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Humanos , Isoindóis , Neoplasias Experimentais/patologia , Fármacos Fotossensibilizantes/síntese química , Resultado do Tratamento , Compostos de Zinco
13.
Nanotechnology ; 26(40): 404001, 2015 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-26376922

RESUMO

Plasmonic antennas are attractive nanostructures for a large variety of studies ranging from fundamental aspects of light-matter interactions at the nanoscale to industry-relevant applications such as ultrasensitive sensing, enhanced absorption in solar cells or solar fuel generation. A particularly interesting feature of these antennas is that they can enhance the fluorescence properties of emitters. Theoretical calculations have shown that nanocone antennas provide ideal results, but a high degree of manufacturing precision and control is needed to reach optimal performance. In this study, we report on the fabrication of nanocones with base diameters and heights in the range of 100 nm with variable aspect ratios using focused ion beam milling of sputtered nano-crystalline gold layers. The controlled fabrication process allows us to obtain cones with tailored plasmon resonances. The measured plasmon spectra show very good agreement with finite-difference time-domain calculations. Theoretical investigations predict that these nanocones can enhance the spontaneous emission rate of a quantum emitter by several hundred times while keeping its quantum efficiency above 60%.

14.
Int J Pharm ; 466(1-2): 382-9, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24657286

RESUMO

Semiconductor quantum dots (QDs) have become promising nanoparticles for a wide variety of biomedical applications. However, the major drawback of QDs is their potential toxicity. Here, we determined possible cytotoxic effects of a set of QDs by systematic photophysical evaluation in vitro as well as in vivo. QDs were synthesized by the hydrothermal aqueous route with sizes in the range of 2.0-3.5 nm. Cytotoxic effects of QDs were studied in the human pancreatic carcinoid cell line BON. Cadmium telluride QDs with or without zinc sulfide shell and coated with 3-mercaptopropionic acid (MPA) were highly cytotoxic even at nanomolar concentrations. Capping with l-glutathione (GSH) or thioglycolic acid (TGA) reduced the cytotoxicity of cadmium telluride QDs and cadmium selenide QDs. Determination of the toxicity of QDs revealed IC50 values in the micromolar range. In vivo studies showed good tolerability of CdSe QDs with ZnS shell and GSH capping. We could demonstrate that QDs with ZnS shell and GSH capping exhibit low toxicity and good tolerability in cell models and living organisms. These QDs appear to be promising candidates for biomedical applications such as drug delivery for enhanced chemotherapy or targeted delivery of light sensitive substances for photodynamic therapy.


Assuntos
Compostos de Cádmio/química , Glutationa/química , Pontos Quânticos/química , Pontos Quânticos/toxicidade , Compostos de Selênio/química , Sulfetos/química , Compostos de Zinco/química , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide/metabolismo , Sistemas de Liberação de Medicamentos , Humanos
15.
Dalton Trans ; 43(11): 4345-50, 2014 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-24194258

RESUMO

Platinum nanotubes are created by galvanic deposition inside porous templates. The effects of the electrolyte's ion concentration and pH, of the applied potential and of the deposition duration on the morphology of the tubes are investigated systematically. The system provides a model electrode platform with accurately tunable geometry for the fundamental investigation of electrochemical transformations. For slow electrochemical reactions, we observe a linear increase of the galvanic current with the length of the nanotubes, and therefore with the specific surface area of the electrode. In contrast to this, inherently fast electrochemical transformations are diffusion-limited and give rise to the same current density independently of the geometry. These results delineate a strategy for optimizing the performance of electrochemical energy conversion devices systematically via nanostructuring the electrode surfaces.

16.
Pediatr Emerg Care ; 29(1): 89-92, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23283275

RESUMO

BACKGROUND: Colchicine is used as an anti-inflammatory drug in the treatment of gout, familial Mediterranean fever, and Behçet disease. However, because of its potent inhibition of mitosis, adverse effects and symptoms of intoxication are frequent. Clinical manifestations of colchicine intoxication include abdominal cramps, diarrhea, and multiorgan failure including cardiovascular collapse with fatal outcome. OBJECTIVE: We report here the case of a 14-year-old girl who ingested 12.5 mg (0.23 mg/kg body weight) colchicine in a suicide attempt. CASE REPORT: Major complaints of this fully conscious patient at the time of presentation ∼2 hours after ingestion of colchicine were nausea and impaired vision. Apart from a colchicine serum concentration of 16.2 ng/mL, no abnormalities were seen in the physical examination and blood tests. Gastrointestinal decontamination by activated charcoal, repeated administrations of sodium sulfate (Glauber salt) and substitution of volume and electrolytes led to complete recovery.


Assuntos
Colchicina/intoxicação , Supressores da Gota/intoxicação , Intoxicação/terapia , Tentativa de Suicídio , Adolescente , Feminino , Humanos
17.
Nano Lett ; 12(8): 4050-4, 2012 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-22823245

RESUMO

Silicon nanowires (SiNW) were formed on large grained, electron-beam crystallized silicon (Si) thin films of only ∼6 µm thickness on glass using nanosphere lithography (NSL) in combination with reactive ion etching (RIE). Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) studies revealed outstanding structural properties of this nanomaterial. It could be shown that SiNWs with entirely predetermined shapes including lengths, diameters and spacings and straight side walls form independently of their crystalline orientation and arrange in ordered arrays on glass. Furthermore, for the first time grain boundaries could be observed in individual, straightly etched SiNWs. After heat treatment an electronic grade surface quality of the SiNWs could be shown by X-ray photoelectron spectroscopy (XPS). Integrating sphere measurements show that SiNW patterning of the multicrystalline Si (mc-Si) starting thin film on glass substantially increases absorption and reduces reflection, as being desired for an application in thin film photovoltaics (PV). The multicrystalline SiNWs directly mark a starting point for research not only in PV but also in other areas like nanoelectronics, surface functionalization, and nanomechanics.

18.
J Inherit Metab Dis ; 35(6): 1051-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22447152

RESUMO

BACKGROUND: Galactose-1-phosphate uridyltransferase deficiency is well known as the underlying defect in classic galactosemia. However, little is known about the consequences of this defect beyond physical disease. AIM: To evaluate psychosocial, educational and occupational outcome as well as health-related quality of life (HRQOL) in adult German patients with galactosemia and to compare information with data from patients with phenylketonuria as well as the general German population. METHODS: Members of the German patient support group for galactosemia received invitation, informed consent form and questionnaires by regular mail from the patient support group. Participation was voluntary. RESULTS: Forty-one out of 66 invited patients participated in this study. Nearly 2/3 of the patients were singles, and the majority of patients were still living with their parents. Frequently, patients had no school leaving certificate, and 30% of the patients had never started or never completed an apprenticeship. Getting along with galactosemia was rated as 'very good' or 'good' although following the diet was a burden. Social well-being and social functioning was lower compared to patients with PKU. DISCUSSION: Patients with galactosemia need a multi-professional team not only focusing on physical and/or biochemical aspects of disease but including also psycho-social dimensions of life.


Assuntos
Galactosemias/psicologia , Adolescente , Adulto , Estudos de Casos e Controles , Escolaridade , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Ocupações , Fenilcetonúrias/psicologia , Psicologia , Qualidade de Vida , Características de Residência , Inquéritos e Questionários , Adulto Jovem
19.
Int J Oncol ; 40(3): 876-88, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22075556

RESUMO

Up-regulation of phosphatidylinositol-3-kinase (PI3K)-AKT signaling facilitates tumor cell growth and inhibits cell demise. The AKT-pathway also plays an important role in cytostatic therapy resistance and response to hypoxia and angiogenesis. Using real-time cell proliferation assay we examined the potency of triciribine in three distinct neuroendocrine gastrointestinal tumor cell lines. Also we investigated triciribine's induction of apoptosis and effects on a broad range of cancer-associated gene products. Furthermore, we characterized the role of PTEN as a possible predictor of sensitivity to triciribine in GEP-NETs. We also looked for additive anti-neoplastic effects of triciribine when combined with conventional cytostatic drugs or other targeted drugs, affecting different molecules of the PI3K-AKT-pathway and we assessed the potency of triciribine to inhibit tumor growth in vivo, by using the chick chorioallantoic membrane assay. Treatment of insulinoma (CM) or gut neuroendocrine tumor cells (STC-1) with triciribine significantly reduced tumor cell growth by 59% and 65%, respectively. By contrast, the highly expressing PTEN carcinoid cell line BON did not respond, even at higher doses. Combinations of triciribine with classic cytostatic drugs as well as drugs targeting other molecules of the PI3K-AKT-pathway led to synergistic anti-proliferative effects. Additional in vivo-evaluations confirmed the anti-neoplastic potency of triciribine. Thus, our data show that inhibition the AKT-pathway potently reduces the growth of GEP-NET cells alone or in combination therapies. AKT inhibition may provide a rationale for future evaluations.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias Gastrointestinais/tratamento farmacológico , Tumores Neuroendócrinos/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Ribonucleosídeos/farmacologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ciclina D1/metabolismo , Neoplasias Gastrointestinais/genética , Neoplasias Gastrointestinais/metabolismo , Neoplasias Gastrointestinais/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Insulinoma/tratamento farmacológico , Insulinoma/genética , Insulinoma/metabolismo , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/patologia , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ribonucleosídeos/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
20.
Pediatr Neurol ; 45(3): 181-4, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21824567

RESUMO

Mucopolysaccharidosis type II (Hunter disease) is a lysosomal storage disease attributable to X-linked deficiency of the enzyme α-L-iduronate-sulfatase. Because of this deficiency, glycosaminoglycanes accumulate in various tissues and body fluids. We describe three patients representing the broad spectrum of Hunter disease and their response to enzyme replacement therapy. Patient 1 did not manifest central nervous system involvement, patient 2 manifested moderate neurologic disease, and patient 3 had already manifested a severe neurologic course during early infancy. In all patients, improvements in visceral organ size, physical capacity, and gastrointestinal functioning were reported. Moreover, all three patients demonstrated a gain in height, improved functioning of the upper limb, and a reduced need for antibiotics to treat upper airway infections. The response to enzyme replacement therapy occurred independent of type of genetic mutation (missense or frame shift), and we observed only mild infusion-related reactions. We conclude that all patients with mucopolysaccharidosis type II (those with and without clinical central nervous system involvement) may benefit from enzyme replacement therapy.


Assuntos
Terapia de Reposição de Enzimas , Iduronato Sulfatase/uso terapêutico , Mucopolissacaridose II/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Trato Gastrointestinal/patologia , Glicosaminoglicanos/uso terapêutico , Humanos , Iduronato Sulfatase/efeitos adversos , Lactente , Recém-Nascido , Masculino , Mucopolissacaridose II/genética , Mucopolissacaridose II/psicologia , Doenças do Sistema Nervoso/etiologia , Tamanho do Órgão/efeitos dos fármacos , Adulto Jovem
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