Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Soft Matter ; 19(25): 4772-4779, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37318232

RESUMO

The number and strength of mechanical connections of cells to their local environment can be indicative of their migration and invasion potential. Gaining direct access to the mechanical properties of individual connections and bringing them into a relationship with the state of disease, however, is a formidable task. Here, we present a method to directly sense focal adhesions and cell-cell contacts with a force sensor to quantify the lateral forces of their anchoring points. We found local lateral forces of 1.0-1.5 nN for focal adhesions and slightly higher values at the interfaces between cells where cell-cell contacts are located. Interestingly, a modified surface layer was observed exhibiting considerably reduced tip friction directly next to the area of a retracting cell edge on the substrate. We expect that this technique can improve the understanding of the relationship between mechanical properties of cell connections and the pathological state of cells in the future.


Assuntos
Adesões Focais , Junções Intercelulares , Fenômenos Mecânicos , Torção Mecânica , Análise Espectral , Adesão Celular
2.
Sci Transl Med ; 13(593)2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980578

RESUMO

Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce low-density lipoprotein (LDL) cholesterol and are used for treatment of dyslipidemia. Current PCSK9 inhibitors are administered via subcutaneous injection. We present a highly potent, chemically modified PCSK9 antisense oligonucleotide (ASO) with potential for oral delivery. Past attempts at oral delivery using earlier-generation ASO chemistries and transient permeation enhancers provided encouraging data, suggesting that improving potency of the ASO could make oral delivery a reality. The constrained ethyl chemistry and liver targeting enabled by N-acetylgalactosamine conjugation make this ASO highly potent. A single subcutaneous dose of 90 mg reduced PCSK9 by >90% in humans with elevated LDL cholesterol and a monthly subcutaneous dose of around 25 mg is predicted to reduce PCSK9 by 80% at steady state. To investigate the feasibility of oral administration, the ASO was coformulated in a tablet with sodium caprate as permeation enhancer. Repeated oral daily dosing in dogs resulted in a bioavailability of 7% in the liver (target organ), about fivefold greater than the plasma bioavailability. Target engagement after oral administration was confirmed by intrajejunal administration of a rat-specific surrogate ASO in solution with the enhancer to rats and by plasma PCSK9 and LDL cholesterol lowering in cynomolgus monkey after tablet administration. On the basis of an assumption of 5% liver bioavailability after oral administration in humans, a daily dose of 15 mg is predicted to reduce circulating PCSK9 by 80% at steady state, supporting the development of the compound for oral administration to treat dyslipidemia.


Assuntos
Oligonucleotídeos Antissenso , Inibidores de PCSK9 , Animais , Cães , Macaca fascicularis , Ratos , Serina Endopeptidases
3.
J Pharm Sci ; 110(1): 228-238, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33212160

RESUMO

In this study a 3D printed capsule designed to break from the physiological pressures in the antropyloric region was evaluated for its ability to deliver the synthetic octapeptide octreotide in beagle dogs when co-formulated with the permeation enhancer sodium caprate. The pressure sensitive capsules were compared to traditional enteric coated hard gelatin capsules and enteric coated tablets. Paracetamol, which is completely absorbed in dogs, was included in the formulations and used as an absorption marker to give information about the in vivo performance of the dosage forms. The pressure sensitive capsules released drug in 50% of the dogs. In the cases where drug was released, there was no difference in octreotide bioavailability or Cmax compared to the enteric coated dosage forms. When comparing all dosage forms, a correlation was seen between paracetamol Cmax and octreotide bioavailability, suggesting that a high drug release rate may be beneficial for peptide absorption when delivered together with sodium caprate.


Assuntos
Peptídeos , Impressão Tridimensional , Administração Oral , Animais , Disponibilidade Biológica , Cápsulas , Cães , Comprimidos com Revestimento Entérico
4.
Front Psychol ; 4: 411, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23847579

RESUMO

Exercise and physical activity have proven benefits for physical and psychological well-being. However, it is not clear if healthy young adults can enhance mood in everyday life through regular exercise. Earlier studies mainly showed positive effects of acute exercise and exercise programs on psychological well-being in children, older people and in clinical populations. Few studies controlled participants' physical activity in daily life, performed besides the exercise program, which can impact results. In addition the transition from mood enhancement induced by acute exercise to medium or long-term effects due to regular exercise is not yet determined. The purpose of this pilot study was to examine the acute effects of an aerobic running training on mood and trends in medium term changes of mood in everyday life of young adults. We conducted a 10-week aerobic endurance training with frequent mood assessments and continuous activity monitoring. 23 apprentices, separated into experimental and control group, were monitored over 12 weeks. To control the effectiveness of the aerobic exercise program, participants completed a progressive treadmill test pre and post the intervention period. The three basic mood dimensions energetic arousal, valence and calmness were assessed via electronic diaries. Participants had to rate their mood state frequently on 3 days a week at five times of measurement within 12 weeks. Participants' physical activity was assessed with accelerometers. All mood dimensions increased immediately after acute endurance exercise but results were not significant. The highest acute mood change could be observed in valence (p = 0.07; η(2) = 0.27). However, no medium term effects in mood states could be observed after a few weeks of endurance training. Future studies should focus on the interaction between acute and medium term effects of exercise training on mood. The decreasing compliance over the course of the study requires the development of strategies to maintain compliance over longer periods.

5.
Neurosci Lett ; 427(2): 83-7, 2007 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-17931775

RESUMO

The present study investigates whether the spatial discrimination of somatosensory stimuli can be improved with training when sets of 1, 2, 3, or 4 simultaneously stimulated electrodes (so called patterns) have to be discriminated. Healthy human subjects were trained over a period of 5 days to discriminate 23 different somatosensory stimulus patterns. Somatosensory stimulation was based on electrical stimuli applied through an array of eight electrodes attached with a cuff to the skin of the left upper arm. Daily sessions consisted of a pretest, a training phase, and a posttest. Pre- and posttests revealed subject's discrimination ability. Performance of a treatment group receiving sensory real training was compared to performance of a control group receiving sham training. Results revealed (1) improvements of discrimination ability in both groups, and (2) a significantly greater discrimination performance throughout the training period in the treatment group as compared to the control group. The present study demonstrates that discrimination of electrocutaneous stimuli can be improved through training. Results illustrate that electrocutaneous stimuli are a possible and easy-to-apply tool for biofeedback settings.


Assuntos
Aprendizagem por Discriminação/fisiologia , Estimulação Elétrica , Sensação/fisiologia , Pele/inervação , Córtex Somatossensorial/fisiologia , Adolescente , Adulto , Biorretroalimentação Psicológica/métodos , Biorretroalimentação Psicológica/fisiologia , Eletrodos , Feminino , Humanos , Masculino , Rememoração Mental/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA