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1.
Pharmaceutics ; 12(10)2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33076292

RESUMO

Liposomes represent suitable tools for the diagnosis and treatment of a variety of diseases, including cancers. To study the role of the human epidermal growth factor receptor 2 (HER2) as target in cancer imaging and image-guided deliveries, liposomes were encapsulated with an intrinsically quenched concentration of a near-infrared fluorescent dye in their aqueous interior. This resulted in quenched liposomes (termed LipQ), that were fluorescent exclusively upon degradation, dye release, and activation. The liposomes carried an always-on green fluorescent phospholipid in the lipid layer to enable tracking of intact liposomes. Additionally, they were functionalized with single-chain antibody fragments directed to fibroblast activation protein (FAP), a marker of stromal fibroblasts of most epithelial cancers, and to HER2, whose overexpression in 20-30% of all breast cancers and many other cancer types is associated with a poor treatment outcome and relapse. We show that both monospecific (HER2-IL) and bispecific (Bi-FAP/HER2-IL) formulations are quenched and undergo HER2-dependent rapid uptake and cargo release in cultured target cells and tumor models in mice. Thereby, tumor fluorescence was retained in whole-body NIRF imaging for 32-48 h post-injection. Opposed to cell culture studies, Bi-FAP/HER2-IL-based live confocal microscopy of a high HER2-expressing tumor revealed nuclear delivery of the encapsulated dye. Thus, the liposomes have potentials for image-guided nuclear delivery of therapeutics, and also for intraoperative delineation of tumors, metastasis, and tumor margins.

2.
Parasitol Res ; 116(12): 3315-3330, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29027596

RESUMO

The results of coproscopical examinations in domestic animals and hedgehogs carried out as routine diagnostics in the years 2003 to 2012 at the Institute for Parasitology, University of Veterinary Medicine Hannover, Germany, are presented. Of 3475 horse faecal samples, 30.1% contained stages of strongyles and 1.3% eggs of Strongyloides westeri and Parascaris equorum, respectively. The most frequently observed parasite stages in 1416 cattle faecal samples were Eimeria oocysts (21.3%) and strongyle eggs or larvae (15.9%). Dictyocaulus viviparus larvae and Fasciola hepatica eggs were identified in 0.9 and 1.3% of samples. Of 574 bovine faecal samples analysed by carbol-fuchsin staining, 39.9% were positive for Cryptosporidium oocysts. Stages of strongyles were found in 52.4% of sheep (n = 374) and 44.9% of goat faeces (n = 98) and Eimeria oocysts in 41.4 and 32.7% of their faeces, respectively. Of 1848 pig faecal samples, 3.0% contained stages of strongyles, 1.6% eggs of Ascaris suum and 3.3% coccidian (Eimeria or Cystoisospora spp.) oocysts. The most frequently detected helminth eggs in faecal samples of dogs (n = 2731) and cats (n = 903) were Toxocara spp. (2.8 and 3.9%, respectively). Cystoisospora oocysts were identified in 5.6% of dog and 2.4% of cat faeces. Furthermore, 0.7% of the cat samples were positive for small Toxoplasma gondii-like oocysts. The faecal samples of rabbits (n = 434) contained eggs of Passalurus ambiguus (3.0%), strongyles (1.8%) and Trichuris leporis (0.2%) as well as Eimeria oocysts (21.2%). The most abundant nematodes in the samples of hedgehogs (n = 205) were Capillaria spp. (39.5%) and Crenosoma striatum (26.8%); coccidian oocysts were found in 14.2% of the samples.


Assuntos
Fezes/parasitologia , Doenças Parasitárias em Animais/parasitologia , Animais , Ascaridoidea , Gatos/parasitologia , Bovinos/parasitologia , Dictyocaulus/isolamento & purificação , Cães/parasitologia , Eimeria/isolamento & purificação , Alemanha , Cabras/parasitologia , Ouriços/parasitologia , Cavalos/parasitologia , Incidência , Metastrongyloidea , Oocistos , Doenças Parasitárias em Animais/epidemiologia , Coelhos , Ovinos/parasitologia , Strongyloides , Suínos/parasitologia
3.
Acta Biomater ; 54: 281-293, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28347861

RESUMO

Molecular targeting plays a significant role in cancer diagnosis and therapy. However, the heterogeneity of tumors is a limiting obstacle for molecular targeting. Consequently, clinically approved drug delivery systems such as liposomes still rely on passive targeting to tumors, which does not address tumor heterogeneity. In this work, we therefore designed and elucidated the potentials of activatable bispecific targeted liposomes for simultaneous detection of fibroblast activation protein (FAP) and the human epidermal growth factor receptor 2 (HER2). The bispecific liposomes were encapsulated with fluorescence-quenched concentrations of the near-infrared fluorescent dye, DY-676-COOH, making them detectable solely post processing within target cells. The liposomes were endowed with a combination of single chain antibody fragments specific for FAP and HER2 respectively, or with the FAP single chain antibody fragment in combination with Trastuzumab, which is specific for HER2. The Trastuzumab based bispecific formulation, termed Bi-FAP/Tras-IL revealed delivery of the encapsulated dye into the nuclei of HER2 expressing cancer cells and caused cell death at significantly higher rates than the free Trastuzumab. Furthermore, fluorescence imaging and live microscopy of tumor models in mice substantiated the delivery of the encapsulated cargo into the nuclei of target tumor cells and tumor stromal fibroblasts. Hence, they convey potentials to address tumor plasticity, to improve targeted cancer therapy and reduce Trastuzumab resistance in the future. STATEMENT OF SIGNIFICANCE: This work demonstrates the design of activatable bispecific liposomes aimed to target HER2, a poor prognosis tumor marker in many tumor types, and fibroblast activation protein (FAP), a universal tumor marker overexpressed on tumor fibroblasts and pericytes of almost all solid tumors. Encapsulating liposomes with a quenched concentration of a NIRF dye which only fluoresced after cellular degradation and activation enabled reliable visualization of the destination of the cargo in cells and animal studies. Conjugating single chain antibody fragments directed to FAP, together with Trastuzumab, a humanized monoclonal antibody for HER2 resulted in the activatable bispecific liposomes. In animal models of xenografted human breast tumors, the remarkable ability of the bispecific probes to simultaneously deliver the encapsulated dye into the nuclei of target tumor cells and tumor fibroblasts could be demonstrated. Hence, the bispecific probes represent model tools with high significance to address tumor heterogeneity and manage Trastuzumab resistance in the future.


Assuntos
Antineoplásicos Imunológicos , Gelatinases/antagonistas & inibidores , Proteínas de Membrana/antagonistas & inibidores , Neoplasias Experimentais/tratamento farmacológico , Anticorpos de Cadeia Única , Trastuzumab , Animais , Antineoplásicos Imunológicos/química , Antineoplásicos Imunológicos/farmacologia , Endopeptidases , Feminino , Gelatinases/metabolismo , Humanos , Lipossomos , Células MCF-7 , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Nus , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Serina Endopeptidases/metabolismo , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/farmacologia , Trastuzumab/química , Trastuzumab/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
4.
J Cell Biol ; 216(3): 695-708, 2017 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-28137779

RESUMO

PINK1 is mutated in Parkinson's disease (PD), and mutations cause mitochondrial defects that include inefficient electron transport between complex I and ubiquinone. Neurodegeneration is also connected to changes in lipid homeostasis, but how these are related to PINK1-induced mitochondrial dysfunction is unknown. Based on an unbiased genetic screen, we found that partial genetic and pharmacological inhibition of fatty acid synthase (FASN) suppresses toxicity induced by PINK1 deficiency in flies, mouse cells, patient-derived fibroblasts, and induced pluripotent stem cell-derived dopaminergic neurons. Lower FASN activity in PINK1 mutants decreases palmitate levels and increases the levels of cardiolipin (CL), a mitochondrial inner membrane-specific lipid. Direct supplementation of CL to isolated mitochondria not only rescues the PINK1-induced complex I defects but also rescues the inefficient electron transfer between complex I and ubiquinone in specific mutants. Our data indicate that genetic or pharmacologic inhibition of FASN to increase CL levels bypasses the enzymatic defects at complex I in a PD model.


Assuntos
Cardiolipinas/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Transporte de Elétrons/fisiologia , Proteínas Quinases/metabolismo , Ubiquinona/metabolismo , Animais , Linhagem Celular Tumoral , Neurônios Dopaminérgicos/metabolismo , Ácido Graxo Sintases/metabolismo , Fibroblastos/metabolismo , Células HeLa , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Mitocôndrias/metabolismo , Mutação/genética , Proteínas Quinases/genética
5.
Data Brief ; 9: 143-8, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27642620

RESUMO

The underlying data demonstrates that fibroblast activation protein (FAP) paves the way for fibrosarcoma cells, which require the proteolysis of the extracellular matrix (ECM) and basement membranes to intravasate from implanted subcutaneous primary tumors into blood vessels, be transported to distant organs where they extravasate from the blood vessels, reattach and proliferate to metastases. The data additionally shows that FAP, when overexpressed on fibrosarcoma cells induces their invasion and formation of spontaneous metastases in multiple organs, particularly after subcutaneous co-implantation of the FAP-expressing and wildtype fibrosarcoma. The raw and processed data presented herein is related to a research article entitled "Potential of activatable FAP-targeting immunoliposomes in intraoperative imaging of spontaneous metastases" (F.L. Tansi, R. Rüger, C. Böhm, R.E. Kontermann, U.K. Teichgraeber, A. Fahr, I. Hilger, 2016) [1]. Furthermore, evidence for the detection of FAP-expressing tumor cells and cells of the tumor stroma by activatable FAP-targeting liposomes is presented in this dataset.

6.
Biomaterials ; 88: 70-82, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26945457

RESUMO

Despite intensive research and medical advances met, metastatic disease remains the most common cause of death in cancer patients. This results from late diagnosis, poor therapeutic response and undetected micrometastases and tumor margins during surgery. One approach to overcome these challenges involves fluorescence imaging, which exploits the properties of fluorescent probes for diagnostic detection of molecular structures at the onset of transformation and for intraoperative detection of metastases and tumor margins in real time. Considering these benefits, many contrast agents suitable for fluorescence imaging have been reported. However, most reports only demonstrate the detection of primary tumors and not the detection of metastases or their application in models of image-guided surgery. In this work, we demonstrate the influence of fibroblast activation protein (FAP) on the metastatic potential of fibrosarcoma cells and elucidate the efficacy of activatable FAP-targeting immunoliposomes (FAP-IL) for image-guided detection of the spontaneous metastases in mice models. Furthermore, we characterized the biodistribution and cellular localization of the liposomal fluorescent components in mice organs and traced their excretion over time in urine and feces. Taken together, activatable FAP-IL enhances intraoperative imaging of metastases. Their high accumulation in metastases, subsequent localization in the bile canaliculi and liver kupffer cells and suitable excretion in feces substantiates their potency as contrast agents for intraoperative imaging.


Assuntos
Fibrossarcoma/patologia , Gelatinases/metabolismo , Lipossomos/metabolismo , Lipossomos/farmacocinética , Proteínas de Membrana/metabolismo , Imagem Molecular/métodos , Metástase Neoplásica/diagnóstico , Serina Endopeptidases/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Endopeptidases , Feminino , Fibrossarcoma/metabolismo , Humanos , Camundongos , Camundongos Nus , Metástase Neoplásica/patologia
7.
Parasitol Res ; 114 Suppl 1: S155-64, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26152416

RESUMO

The adulticidal efficacy of a topical combination of emodepside 2.1 % (w/v) plus praziquantel 8.6 % (w/v) (Profender® spot-on for cats, Bayer) against adult Aelurostrongylus abstrusus nematodes was evaluated in two randomised, placebo-controlled laboratory efficacy studies. Each study involved 16 cats experimentally inoculated with L3 (800 and 600 each in studies no. 1 and 2, respectively) and randomised into two study groups of 8 cats each after onset of patency. While cats in the treatment group in study no. 1 received a single spot-on application at the minimum therapeutic dose (3 mg/kg emodepside and 12 mg/kg praziquantel), cats in study no. 2 were treated twice with an interval of 14 days. The faecal output of first stage larvae was monitored throughout the study. Necropsy was conducted 4 or 5 weeks after the (first) treatment and the worm counts were used for efficacy calculations. The control groups showed a geometric mean of the total worm count (live and dead worms) of 28.8 (study no. 1) and 17.6 (study no. 2), respectively. All control animals were infected. While the single treatment in study no. 1 resulted in a reduction of the total worm burden by 73.0 % (p = 0.0070), the treatment protocol in study no. 2 was 99.2 % effective (p = 0.0035). Based on live worm counts, the efficacy in study no. 2 was 100 % (p = 0.0030). It is concluded that two applications of Profender® spot-on given two weeks apart represent a safe and highly efficacious treatment regime against feline aelurostrongylosis.


Assuntos
Doenças do Gato/tratamento farmacológico , Depsipeptídeos/uso terapêutico , Metastrongyloidea , Infecções por Nematoides/veterinária , Praziquantel/uso terapêutico , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/uso terapêutico , Doenças do Gato/parasitologia , Gatos , Depsipeptídeos/administração & dosagem , Combinação de Medicamentos , Larva/efeitos dos fármacos , Infecções por Nematoides/tratamento farmacológico , Praziquantel/administração & dosagem
8.
Parasitol Res ; 114 Suppl 1: S175-84, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26152418

RESUMO

This study aimed to evaluate the efficacy of an emodepside 2.1 % (w/v)/praziquantel 8.6 % (w/v) topical solution (Profender® spot-on for cats) in the prevention of lactogenic Toxocara cati infections. A controlled test was performed with two groups of 8 cats with confirmed pregnancy. All cats were infected with daily doses of 2000 T. cati eggs for 10 consecutive days starting 50 days post conception to produce an acute infection. Treatment was performed 60 days post conception. Queens in the treatment group received the emodepside/praziquantel solution at the minimum therapeutic dose (3 mg/kg emodepside and 12 mg/kg praziquantel), while the control group was treated with a placebo spot-on. Efficacy was evaluated 56 days post partum by necropsy of one randomly selected kitten of each litter and comparison of the worm burdens between the study groups. Additionally the necropsy results were supported by quantification of worms expelled with the faeces after deworming of the remaining kittens and all queens. The treatment in late pregnancy resulted in an efficacy of 98.7 % (p < 0.0001). All necropsied control kittens were infected (geometric mean 30.6). Seven of 8 kittens from treated mothers were free of T. cati (geometric mean 0.4). Worm counts after deworming reflected the results obtained at necropsy. No side effects of the treatment were observed. It is concluded that treatment with an emodepside/praziquantel spot-on solution during late pregnancy effectively prevents lactogenic transmission of T. cati to the offspring. The study design facilitated the generation of reliable data, while at the same time a minimum number of animals was sacrificed.


Assuntos
Anti-Helmínticos/uso terapêutico , Doenças do Gato/tratamento farmacológico , Depsipeptídeos/uso terapêutico , Transmissão Vertical de Doenças Infecciosas/veterinária , Praziquantel/uso terapêutico , Administração Tópica , Animais , Anti-Helmínticos/administração & dosagem , Doenças do Gato/parasitologia , Gatos , Depsipeptídeos/administração & dosagem , Combinação de Medicamentos , Fezes/parasitologia , Feminino , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Praziquantel/administração & dosagem , Gravidez , Toxocara/efeitos dos fármacos , Toxocaríase/tratamento farmacológico
9.
Neuron ; 79(6): 1197-207, 2013 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-24050405

RESUMO

Local inhibitory microcircuits in the medial entorhinal cortex (MEC) and their role in network activity are little investigated. Using a combination of electrophysiological, optical, and morphological circuit analysis tools, we find that layer II stellate cells are embedded in a dense local inhibitory microcircuit. Specifically, we report a gradient of inhibitory inputs along the dorsoventral axis of the MEC, with the majority of this local inhibition arising from parvalbumin positive (PV+) interneurons. Finally, the gradient of PV+ fibers is accompanied by a gradient in the power of extracellular network oscillations in the gamma range, measured both in vitro and in vivo. The reported differences in the inhibitory microcircuitry in layer II of the MEC may therefore have a profound functional impact on the computational working principles at different locations of the entorhinal network and influence the input pathways to the hippocampus.


Assuntos
Córtex Entorrinal/citologia , Potenciais Pós-Sinápticos Inibidores/fisiologia , Interneurônios/fisiologia , Rede Nervosa/fisiologia , Inibição Neural/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Animais Recém-Nascidos , Estimulação Elétrica , Potenciais Evocados/fisiologia , Ácido Glutâmico/farmacologia , Técnicas In Vitro , Potenciais Pós-Sinápticos Inibidores/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Lisina/análogos & derivados , Lisina/metabolismo , Rede Nervosa/efeitos dos fármacos , Inibição Neural/efeitos dos fármacos , Parvalbuminas/metabolismo , Técnicas de Patch-Clamp , Peptídeos/metabolismo , Polímeros , Ratos , Ratos Wistar , Estatísticas não Paramétricas , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores/metabolismo
10.
Parasitol Res ; 111(5): 2123-7, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22864864

RESUMO

Toxocara cati is the most prevalent gastrointestinal helminth in cats worldwide, with cats of all ages at risk of infection. An anthelminthic treatment that not only affects the gut-dwelling stages of this parasite but is also effective against developmental stages in the tissue has the advantage that the pathology caused by migrating larvae is minimized and the need for repeated treatments is reduced. This study was conducted to evaluate the efficacy of milbemycin oxime/praziquantel tablets (Milbemax®, Novartis) against third-stage larvae of T. cati in comparison to a spot-on formulation of emodepside and praziquantel (Profender®, Bayer). Twenty-four kittens were experimentally infected with T. cati and randomly allocated to three study groups. Treatments were performed at the minimum therapeutic dosage 5 days after the experimental infection. The development of patent infections was monitored and all cats were dewormed 50 days post-infection. Efficacies were calculated based on counts of excreted worms in the treated groups compared to a negative control group. Seven of the eight cats in the negative control group developed a patent T. cati infection and all cats were excreting worms at the end of the study (geometric mean worm count 18.1). No efficacy could be observed for the milbemycin oxime-treated animals. All cats developed a patent infection and excreted worms (geometric mean worm count 27.7). The treatment with Profender® was 98.5 % effective against L3 of T. cati. One cat developed a patent infection and was excreting worms at the end of the study (geometric mean worm count 0.3). No adverse reactions were noted in either treatment group.


Assuntos
Anti-Helmínticos/administração & dosagem , Doenças do Gato/tratamento farmacológico , Depsipeptídeos/administração & dosagem , Macrolídeos/administração & dosagem , Praziquantel/administração & dosagem , Toxocara/efeitos dos fármacos , Toxocaríase/tratamento farmacológico , Animais , Anti-Helmínticos/efeitos adversos , Doenças do Gato/parasitologia , Gatos , Depsipeptídeos/efeitos adversos , Modelos Animais de Doenças , Quimioterapia Combinada/métodos , Feminino , Macrolídeos/efeitos adversos , Masculino , Praziquantel/efeitos adversos , Resultado do Tratamento
11.
Hippocampus ; 22(6): 1350-62, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21853502

RESUMO

Cannabis consumption results in impaired learning. The proper synchronization of neuronal activity in the mammalian hippocampus gives rise to network rhythms that are implicated in memory formation. Here, we have studied the impact of cannabinoids on hippocampal sharp waves and associated ripple oscillations using field- and whole-cell voltage-clamp recordings. We demonstrate that the activation of cannabinoid receptor 1 suppresses sharp wave-ripples (SWRs) in mice in vivo and in vitro. This suppression was paralleled by a selective reduction of SWR-associated inward but not outward charge transfer, demonstrating an impairment of excitation due to cannabinoid exposure. Adenosine, a presynaptic modulator of glutamate release, mimicked and occluded the observed consequences of cannabinoids on SWRs. We conclude that inhibition of glutamatergic feed-forward excitation can explain cannabinoid-mediated disruption of SWRs and may account for cannabinoid-induced impairment of hippocampus-dependent memory.


Assuntos
Canabinoides/farmacologia , Ácido Glutâmico/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Animais , Cicloexanóis/farmacologia , Relação Dose-Resposta a Droga , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/metabolismo , Receptor CB1 de Canabinoide/agonistas , Receptor CB1 de Canabinoide/metabolismo
12.
Vasc Health Risk Manag ; 3(5): 763-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18078029

RESUMO

OBJECTIVES: In the present study, patients with severely compromized left ventricular function underwent magnetic resonance imaging (MRI) before and after coronary artery bypass grafting (CABG). Although improvement of global myocardial contractile function has been shown before, we sought to evaluate whether a functional contractile improvement may be determinable on a myocardial segmental basis after CABG surgery. METHODS: Thirty-three CABG patients with left ventricular ejection fraction (LVEF) < or =30% prospectively underwent MRI to compare pre- and postoperative functional data. At follow-up, all survivors underwent clinical assessment. In 16 patients (three patients died perioperatively, 13 could were lost to MRI follow-up because of cardiac resynchronization therapy and other reasons) postoperative MRI scanning was performed. RESULTS: In-hospital mortality was 9%. At 20 +/- 2 months after surgery, New York Heart Association class improved from 3.0 +/- 0.1 to 2.2 +/- 0.2 (p < 0.01). Left ventricular end-diastolic volumes decreased significantly from 229 +/- 14 mL to 189 +/- 19 mL (p < 0.05). LV end-systolic volumes decreased significantly from 163 +/- 13 mL to 126 +/- 17 mL (p < 0.05). LVEF improved from 30 +/- 2% to 36 +/- 3% (p < 0.05). On a segmental basis, 42 out of 875 segments (4.8%) had normal function before surgery, at follow-up, 177 segments (20.4%) had normal regional function (p < 0.05). CONCLUSIONS: Patients who undergo CABG surgery with severely compromized left ventricular function, postoperative MRI shows improved global and segmental cardiac function at mid-term follow-up. At the same time there is considerable clinical improvement.


Assuntos
Ponte de Artéria Coronária , Função Ventricular Esquerda/fisiologia , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
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