Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
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.
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
4.
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
5.
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.

6.
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
7.
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%.

8.
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
9.
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.

10.
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
11.
J Inherit Metab Dis ; 34(2): 421-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21347587

RESUMO

BACKGROUND: Long-term outcome in classic galactosemia is disappointing with impaired IQ, reduced bone mineral density, and fertility problems. Moreover, speech impairment is common with conflicting reports regarding frequency, pattern, and relation to IQ. OBJECTIVE: To evaluate speech and cognitive performance in patients with galactosemia. METHODS: Speech performance was evaluated by means of the Hierarchische Wortlisten, a German word-repetition test for the diagnosis of apraxia of speech, using real words and pseudo-words. Cognitive performance was evaluated by use of age-appropriate German versions of the Wechsler Scales. RESULTS: In a cohort of 32 patients (12 females, 20 males; mean age 21.2 ± 7.2 years) with classic galactosemia, the mean IQ was 76.2 ± 14.8. Eighty-four percent of the patients passed the speech test with errors. Speech errors were much more related to pseudo-words than real words and were predominantly observed in words with three and four syllables. The performance in producing words was correlated to the IQ scores. CONCLUSION: Impairment of speech affects a significant number of patients with galactosemia, appears in early childhood, and persists into adulthood. The pattern of speech impairment may allow labeling as apraxia of speech. In many cases impaired speech is related to decreased IQ.


Assuntos
Transtornos Cognitivos/diagnóstico , Galactosemias/diagnóstico , Adolescente , Adulto , Criança , Transtornos Cognitivos/complicações , Estudos de Coortes , Estudos Transversais , Feminino , Galactosemias/complicações , Alemanha , Humanos , Testes de Inteligência , Masculino , Fonética , Reprodutibilidade dos Testes , Fala , Distúrbios da Fala/complicações , Distúrbios da Fala/diagnóstico
12.
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
13.
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
14.
N Engl J Med ; 347(26): 2122-32, 2002 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-12501224

RESUMO

BACKGROUND: Hyperphenylalaninemia is a common inherited metabolic disease that is due to phenylalanine hydroxylase deficiency, and at least half the affected patients have mild clinical phenotypes. Treatment with a low-phenylalanine diet represents a substantial psychosocial burden, but alternative treatments have not been effective. METHODS: To explore the therapeutic efficacy of tetrahydrobiopterin, we performed a combined phenylalanine-tetrahydrobiopterin loading test and analyzed the in vivo rates of [13C]phenylalanine oxidation in 38 children with phenylalanine hydroxylase deficiency (age range, 1 day to 17 years). We assessed whether responsiveness to tetrahydrobiopterin was associated with specific genotypes, and we mapped mutations using a structural model of the phenylalanine hydroxylase monomer. RESULTS: In 27 (87 percent) of 31 patients with mild hyperphenylalaninemia (10 patients) or mild phenylketonuria (21 patients), tetrahydrobiopterin significantly lowered blood phenylalanine levels. Phenylalanine oxidation was significantly enhanced in 23 of these 31 patients (74 percent). Conversely, none of the seven patients with classic phenylketonuria had a response to tetrahydrobiopterin as defined in this study. Long-term treatment with tetrahydrobiopterin in five children increased daily phenylalanine tolerance, allowing them to discontinue their restricted diets. Seven mutations (P314S, Y417H, V177M, V245A, A300S, E390G, and IVS4-5C-->G) were classified as probably associated with responsiveness to tetrahydrobiopterin, and six mutations (A403V, F39L, D415N, S310Y, R158Q, and I65T) were classified as potentially associated. Four mutations (Y414C, L48S, R261Q, and I65V) were inconsistently associated with this phenotype. Mutations connected to tetrahydrobiopterin responsiveness were predominantly in the catalytic domain of the protein and were not directly involved in cofactor binding. CONCLUSIONS: Tetrahydrobiopterin responsiveness is common in patients with mild hyperphenylalaninemia phenotypes. Responsiveness cannot consistently be predicted on the basis of genotype, particularly in compound heterozygotes.


Assuntos
Biopterinas/análogos & derivados , Biopterinas/uso terapêutico , Fenilalanina/metabolismo , Fenilcetonúrias/tratamento farmacológico , Adolescente , Biopterinas/farmacologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Conformação Molecular , Mutação de Sentido Incorreto , Oxirredução/efeitos dos fármacos , Fenilalanina/sangue , Fenilalanina Hidroxilase/química , Fenilalanina Hidroxilase/genética , Fenilcetonúrias/classificação , Fenilcetonúrias/genética , Fenilcetonúrias/metabolismo , Estudos Prospectivos
15.
Acta Paediatr ; 96(455): 84-6, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17391450

RESUMO

UNLABELLED: Gastrointestinal symptoms in Fabry disease were first described independently by William Anderson and Johannes Fabry. Case reports and case series suggest that the whole gastrointestinal tract may be affected in patients with Fabry disease. The Fabry Outcome Survey (FOS) database supports these observations. The overall prevalence of gastrointestinal involvement reported in a study of 342 patients (271 adults; 71 children) enrolled in FOS was 52% (49.8% in adults, 60.8% in children). Abdominal pain was the most prevalent symptom. The median age at onset of gastrointestinal symptoms was 14 years, similar to the age at onset of acroparaesthesia. The prevalence of gastrointestinal symptoms was reduced in patients after receiving enzyme replacement therapy with agalsidase alfa for 12 and 24 months. There was no correlation between gastrointestinal symptoms and body mass index. CONCLUSION: Gastrointestinal symptoms in Fabry disease may have been underestimated. The FOS database supports previous reports of beneficial effects of enzyme replacement therapy on gastrointestinal symptoms in Fabry disease.


Assuntos
Doença de Fabry/complicações , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/epidemiologia , alfa-Galactosidase/uso terapêutico , Humanos , Isoenzimas/uso terapêutico , Prevalência , Proteínas Recombinantes
16.
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
17.
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
18.
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.

19.
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
20.
Med Klin (Munich) ; 100(10): 617-23, 2005 Oct 15.
Artigo em Alemão | MEDLINE | ID: mdl-16220250

RESUMO

BACKGROUND AND PURPOSE: Advances in diagnosis and therapy of inborn errors of metabolism have improved prognosis and outcome of affected patients. Many patients have reached adulthood already, and thus may be attended by adult physicians. In this study the authors evaluated the situation of adult patients with metabolic diseases in Germany. METHODS: 26 pediatric departments with a special metabolic unit were asked to answer a questionnaire of 14 questions. RESULTS: 16/26 departments completed the questionnaire. Only one hospital maintains an outpatient department for adult patients with metabolic diseases. Two additional internal medical departments collaborate with a pediatric metabolic center. Many of the answering pediatric departments conceded problems in the treatment of adult patients with metabolic diseases. CONCLUSION: Adults with inborn errors of metabolism are mostly attended by pediatricians, also beyond adolescence. There is an urgent need for structures that guarantee appropriate and sufficient treatment of this continuously growing population.


Assuntos
Erros Inatos do Metabolismo/diagnóstico , Equipe de Assistência ao Paciente/estatística & dados numéricos , Adolescente , Adulto , Criança , Estudos Transversais , Feminino , Alemanha , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Inquéritos Epidemiológicos , Humanos , Incidência , Masculino , Medicina/estatística & dados numéricos , Erros Inatos do Metabolismo/epidemiologia , Erros Inatos do Metabolismo/terapia , Pediatria/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Especialização
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA