Search results for "zur"

Natural Course, Clinical Profile, and Treatment Strategies for Cerebral Cavernous Malformations

2022

A large body of evidence has suggested that the natural biology for symptomatic cerebral cavernous malformations (CCMs) is dynamic. These lesions exhibit a temporal clustering epiphenomenon and usually manifest with multispectral clinical patterns, the most relevant being hemorrhagic and seizurogenic events. Most patients with cerebral cavernous malformations are asymptomatic, and the lesions are detected as incidentalomas. However, association with the CCM3 gene, Zabramski type I and II lesions, and brainstem location have the propensity to increase the bleeding events. The rebleeding risk is 20%/year per lesion, which supports the need for surgical strategies for brainstem cavernous malfo…

The selection of serum-independent PC12 cells for a more-reliable manganese cytotoxicity test.

2007

A major issue concerning the protocols of heavy metal cytotoxicity tests with PC12 cells was the hypothesis that serum in the culture medium might sequester the metal, thus altering the results obtained. However, serum withdrawal impairs the viability of PC12 cells themselves, thus impeding cytotoxicity testing in the absence of serum. In this study, we repeatedly selected undifferentiated, totally non-adherent PC12 cells in Petri dishes. Surprisingly, we discovered that these cells could survive and proliferate in serum-free medium. Moreover, features such as NGF-responsiveness, resazurin reduction potential, doubling rate, protein content, and basal caspase-3 enzyme activity, were equiva…

Identification of new P-glycoprotein inhibitors derived from cardiotonic steroids

2014

P-glycoprotein (ABCB1, MDR1) is capable of extruding chemotherapeutics outside the cell and its overexpression in certain cancer cells may cause failure of chemotherapy. Many attempts were carried out to identify potent inhibitors of this transporter and numerous compounds were shown to exert inhibitory effects in vitro, but so far none were able to make their way to the clinic due to serious complications. Natural compounds represent a great source of therapeutics, which are believed to be safe and effective. Therefore, we have screened a large library of naturally occurring cardiotonic steroids and their derivatives using high throughput flow cytometry. We were able to identify six compou…

AAV vector-mediated overexpression of CB1 cannabinoid receptor in pyramidal neurons of the hippocampus protects against seizure-induced excitoxicity.

2010

The CB1 cannabinoid receptor is the most abundant G-protein coupled receptor in the brain and a key regulator of neuronal excitability. There is strong evidence that CB1 receptor on glutamatergic hippocampal neurons is beneficial to alleviate epileptiform seizures in mouse and man. Therefore, we hypothesized that experimentally increased CB1 gene dosage in principal neurons would have therapeutic effects in kainic acid (KA)-induced hippocampal pathogenesis. Here, we show that virus-mediated conditional overexpression of CB1 receptor in pyramidal and mossy cells of the hippocampus is neuroprotective and moderates convulsions in the acute KA seizure model in mice. We introduce a recombinant a…

Relationship between the caudate nucleus and the dorsal hippocampus, in the cat.

1972

In Vitro and In Silico Studies of Two 1,4-Naphthoquinones and Their Topical Formulation in Bigels.

2021

Background: 1,4-Naphthoquinones (1,4-NQs) are secondary plant metabolites with numerous biological activities. 1,4-NQs display low water solubility and poor bioavailability. Bigels are a new technology with great potential, which are designated as drug delivery systems. Biphasic bigels consisting of solid and liquid components represent suitable formulations improving diffusion and bioavailability of NQs into the skin. Objective: We evaluated the in silico and in vitro activity of 5,8-dihydroxy-1,4-naphthoquinone (M1) and 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone (M2) on elastase and assessed their cytotoxicity towards COLO38 melanoma cells. The 1,4-NQs were loaded into bigels for topi…

Two new flavonoids from Dracaena usambarensis Engl.

2020

Abstract Investigations of the root extract of Dracaena usambarensis Engl. for anticancer principles led to the characterization of one new homoisoflavonoid, (3S)-3,4ʹ,5,6-tetrahydroxy-7-methoxyhomoisoflavanone (1) and a new retrodihydrochalcone, 4ʹ,4-dihydroxy-2,3-dimethoxydihydrochalcone (2) along with six previously reported compounds, including two homoisoflavonoids, 7-O-methyl-8-demethoxy-3-hydroxy-3,9-dihydropunctatin (3) and loureiriol (4); a phenolic amide, 3-(4ʹʹʹ-hydroxyphenyl)-N-[2ʹ-(4ʹʹ-hydroxyphenyl)-2ʹ-methoxyethyl]acrylamide (5); a spirostane, 25S-spirosta-1,4-dien-3-one (6) and two steroids, stigmasterol (7) and stigmasterol 3-O-β-D-glucopyranoside (8). The structures of 1-8…

Liquid chromatography/atmospheric pressure chemical ionization-mass spectrometric analysis of benzoylurea insecticides in citrus fruits.

2000

A liquid chromatography (LC) method for the quantitative determination of three benzoylurea insecticide residues (diflubenzuron, flufenoxuron and hexaflumuron) in citrus fruits is described. Residues were successfully separated on a C18 column by methanol/water gradient elution. Detection was by negative-ion, selected-ion monitoring atmospheric pressure chemical ionization-mass spectrometry (APCI-MS); the main ions were [M - H]-, and the secondary fragment ions were [M - H - HF]-. Useful confirmatory information can thus be obtained at low extraction voltages from losses of HF. Detection limits for standard solutions were 10 fg injected and good linearity and reproducibility were obtained. …

Interesujące gatunki chrząszczy (Coleoptera) z Puszczy Piskiej

2022

W lipcu 2002 roku huragan zniszczył drzewostany na znacznym obszarze Puszczy Piskiej. Część uszkodzonego lasu – 475 ha – pozostawiono bez ingerencji (Las Ochronny „Szast”) – do naturalnej sukcesji. W latach 2005–2021 badano chrząszcze na wybranych powierzchniach pohuraganowych i kontrolnych. Do odłowów stosowano różne typy pułapek (IBL-2bis, Netocia, Moerickego). Uzupełnieniem były odłowy Coleoptera metodą „na upatrzonego” oraz analizy potencjalnego materiału lęgowego chrząszczy. W sumie w trakcie badań wykazano 1000 gatunków Coleoptera. W pracy przedstawiono dane taksonów: rzadkich, reliktów puszczańskich i wymienionych w Czerwonej Liście zwierząt ginących i zagrożonych w Polsce. Ogółem 32…

Characterization of entropy measures against data loss: Application to EEG records

2012

This study is aimed at characterizing three signal entropy measures, Approximate Entropy (ApEn), Sample Entropy (SampEn) and Multiscale Entropy (MSE) over real EEG signals when a number of samples are randomly lost due to, for example, wireless data transmission. The experimental EEG database comprises two main signal groups: control EEGs and epileptic EEGs. Results show that both SampEn and ApEn enable a clear distinction between control and epileptic signals, but SampEn shows a more robust performance over a wide range of sample loss ratios. MSE exhibits a poor behavior for ratios over a 40% of sample loss. The EEG non-stationary and random trends are kept even when a great number of samp…