Search results for "preclinical"

The non-aromatizable androgen dihydrotestosterone (DHT) facilitates sexual behavior in ovariectomized female rats primed with estradiol

2020

Abstract It is still unclear whether Testosterone (T) increases sexual desire through a stimulation of the androgen receptor in relevant brain regions or through its conversion to estrogens. The aim of this study was to clarify the mechanisms of T facilitation of female sexual desire by assessing the effect of a non-aromatizable androgen (Dihydrotestosterone, DHT) in a validated animal model. Ovariectomized (OVX) Long-Evans rats were treated with oil (O) + O, 10 mcg Estradiol Benzoate (EB) + O, 10 mcg EB + 500 mcg Progesterone (P), O + 500 mcg DHT or 10 mcg EB + 500 mcg DHT (n = 12 per group). EB was administered 48 h, while P and DHT 4 h, prior to 4 sexual behavioral testing sessions in bi…

Impact of

2018

Drosophila melanogaster has been for over a century the model of choice of several neurobiologists to decipher the formation and development of the nervous system as well as to mirror the pathophysiological conditions of many human neurodegenerative diseases. The rare disease Friedreich’s ataxia (FRDA) is not an exception. Since the isolation of the responsible gene more than two decades ago, the analysis of the fly orthologue has proven to be an excellent avenue to understand the development and progression of the disease, to unravel pivotal mechanisms underpinning the pathology and to identify genes and molecules that might well be either disease biomarkers or promising targets for therap…

A new trifocal corneal inlay for presbyopia

2021

[EN] Corneal inlays (CIs) are the most recent surgical procedure for the treatment of presbyopia in patients who want complete independence from the use of glasses or contact lenses. Although refractive surgery in presbyopic patients is mostly performed in combination with cataract surgery, when the implantation of an intraocular lens is not necessary, the option of CIs has the advantage of being minimally invasive. Current designs of CIs are, either: small aperture devices, or refractive devices, however, both methods do not have good performance simultaneously at intermediate and near distances in eyes that are unable to accommodate. In the present study, we propose the first design of a …

Innovative ultrasound systems for preclinical studies: design and production of new instruments and set-ups for in vitro and in vivo experiments – Si…

One pot light assisted green synthesis, storage and antimicrobial activity of dextran stabilized silver nanoparticles.

2014

Background Green synthesis of nanomaterials finds the edge over chemical methods due to its environmental compatibility. Herein, we report green synthesis of silver nanoparticles (Ag NPs) mediated with dextran. Dextran was used as a stabilizer and capping agent to synthesize Ag NPs using silver nitrate (AgNO3) under diffused sunlight conditions. Results UV–vis spectra of as synthesized Ag nanoparticles showed characteristic surface plasmon band in the range from ~405-452 nm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies showed spherical Ag NPs in the size regime of ~50-70 nm. Face centered cubic lattice of Ag NPs was confirmed by powder X-ray diffraction (PXRD…

PET Imaging of the Impact of Extracellular pH and MAP Kinases on the p-Glycoprotein (Pgp) Activity

2012

The functional activity of p-glycoprotein (Pgp) can be increased in vitro by an extracellular acidosis via activation of MAP kinases (p38, ERK1/2). In order to study these effects in vivo a new (68)Ga-labeled PET tracer was developed which serves as a substrate of the Pgp and therefore indirectly mirrors the Pgp activity. For in vivo studies, experimental tumors were imaged under acidic conditions (inspiratory hypoxia, injection of lactic acid) and during inhibition of MAP kinases in a μ-PET system. In vitro, [(68)Ga]MFL6.MZ showed an accumulation within the cells of about 20% which was increased to 30% by Pgp inhibition. In solid tumors a marked tracer uptake was observed showing spatial h…

Projection and Pinhole-Based Data Acquisition for Small-Animal SPECT Using Storage Phosphor Technology

2007

Three-dimensional Single Photon Emission Computed Tomography (SPECT) can provide high-resolution insight into biomolecular distribution and pharmacokinetics. However, instrument availability and distribution is limited at present,and imaging times can be considerable. To evaluate the large array of novel agents which are becoming available,we find that storage phosphor-based in vivo imaging can provide an important,rapid-throughput transition from the traditional ex vivo sacrifice/gamma counting and autoradiography to full-time course SPECT.

Effects of Mn2+ on the responses induced by different spasmogens in the oestrogen-primed rat uterus

1997

Abstract We investigated the effect of Mn 2+ on the mechanical responses evoked by high K + (60 mM) or low Na + (25 mM) solutions, oxytocin and neurokinin A in the oestrogen-primed rat uterus. In a Ca 2+ -free, Mn 2+ (0.54 mM)-containing solution, high K + or low Na + solutions produced contractions of smaller amplitude than those observed in a normal Ca 2+ (0.54 mM) solution, which were abolished by nifedipine (1 μM). Oxytocin (1 μM) and neurokinin A (1 μM, in the presence of phosphoramidon 1 μM) evoked nifedipine-insensitive contractile responses similar to (oxytocin) or smaller (neurokinin A) in amplitude than those observed in Ca 2+ (0.54 mM)-containing solution. In strips loaded with C…

Impact of pharmacological and psychological treatment methods of depressive and anxiety disorders on cognitive functioning

2014

Anxiety and depressive disorders are characterized by a number of clinical symptoms like decreased mood, apathy, anhedonia and anxiety. An important element of the clinical picture is also neurocognitive impairment. The most common treatment methods for depression and anxiety are pharmacology, psychotherapy or a combination of both methods. The data from literature show that those treatment methods lead to an improvement of clinical symptoms, but they exert a possible impact on cognitive functions. However the study results referring both to the role of pharmacological treatment and psychotherapy in this domain are still inconsistent. There is an increasing number of accessible data confirm…

Computed Tomography in Brain Tumors

1981

Craniocerebral injury and brain tumor are the two most important indications for CT studies. There is unanimous agreement that computed tomography is unequalled in its diagnostic accuracy in demonstration of intracranial tumors. Our own experience is based on observations in 3,750 patients with brain tumors or cerebral metastases who were studied in the period from December 1974 to March 1980 (Table 1). Initial CT studies demonstrated the intracranial tumor or tumors in 3,589 cases (95.7%). Several CT examinations were necessary for diagnosis of a brain tumor in 112 patients (3.0%). Other diagnostic procedures or postmortem studies revealed a brain tumor which had not been demonstrated with…