Search results for "Assays"
showing 10 items of 546 documents
General Cytotoxicity Assessment by Means of the MTT Assay
2014
Cytotoxicity assays were among the first in vitro bioassay methods used to predict toxicity of substances to various tissues. In vitro cytotoxicity testing provides a crucial means for safety assessment and screening, and for ranking compounds. The choice of using a particular cytotoxicity assay technology may be influenced by specific research goals. As such, four main classes of assays are used to monitor the response of cultured cells after treatment with potential toxicants. These methods measure viability, cell membrane integrity, cell proliferation, and metabolic activity. In this chapter, we focus on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reducti…
Leishmania tarentolae and Leishmania infantum in humans, dogs and cats in the Pelagie archipelago, southern Italy.
2021
Visceral leishmaniasis (VL) caused by Leishmania infantum is endemic in the Mediterranean basin with most of the infected human patients remaining asymptomatic. Recently, the saurian-associated Leishmania tarentolae was detected in human blood donors and in sheltered dogs. The circulation of L. infantum and L. tarentolae was investigated in humans, dogs and cats living in the Pelagie islands (Sicily, Italy) by multiple serological and molecular testing. Human serum samples (n = 346) were tested to assess the exposure to L. infantum by immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) and to L. tarentolae by IFAT. Meanwhile, sera from do…
Assessing ecotoxicity of biomining effluents in stream ecosystems by in situ invertebrate bioassays : A case study in Talvivaara, Finland
2017
Mining of sulfide-rich pyritic ores produces acid mine drainage waters and has induced major ecological problems in aquatic ecosystems worldwide. Biomining utilizes microbes to extract metals from the ore, and it has been suggested as a new sustainable way to produce metals. However, little is known of the potential ecotoxicological effects of biomining. In the present study, biomining impacts were assessed using survival and behavioral responses of aquatic macroinvertebrates at in situ exposures in streams. The authors used an impedance conversion technique to measure quantitatively in situ behavioral responses of larvae of the regionally common mayfly, Heptagenia dalecarlica, to discharge…
Synthesis and Antiproliferative Activity of 2,5-bis(3′-Indolyl)pyrroles, Analogues of the Marine Alkaloid Nortopsentin
2013
2,5-bis(3′-Indolyl)pyrroles, analogues of the marine alkaloid nortopsentin, were conveniently prepared through a three step procedure in good overall yields. Derivatives 1a and 1b exhibited concentration-dependent antitumor activity towards a panel of 42 human tumor cell lines with mean IC50 values of 1.54 μM and 0.67 μM, respectively. Investigating human tumor xenografts in an ex-vivo clonogenic assay revealed selective antitumor activity, whereas sensitive tumor models were scattered among various tumor histotypes.
New 2-Methoxy Acetylenic Acids and Pyrazole Alkaloids from the Marine Sponge Cinachyrella sp.
2017
Three new 2-methoxy acetylenic acids (1–3) and a known derivative (4), in addition to three new natural pyrazole alkaloids (5–7) were isolated from an Indonesian marine sponge of the genus Cinachyrella. Compounds 5 and 6 have previously been reported as synthetic compounds. The structures of the new compounds were established on the basis of one- and two-dimensional NMR spectroscopy as well as by mass spectrometric data. The absolute configuration of the new acetylenic acid derivatives (1–3) was established by ECD spectroscopy. All isolated compounds were evaluated for their cytotoxicity against L5178Y mouse lymphoma cells. Compounds 1–4 exhibited strong activity with an IC50 value of 0.3 µ…
N-Cinnamoyltetraketide Derivatives from the Leaves of Toussaintia orientalis
2015
Seven N-cinnamoyltetraketides (1−7), including the new Ztoussaintine E (2), toussaintine F (6), and toussaintine G (7), were isolated from the methanol extract of the leaves of Toussaintia orientalis using column chromatography and HPLC. The configurations of E-toussaintine E (1) and toussaintines A (3) and D (5) are revised based on single-crystal X-ray diffraction data from racemic crystals. Both the crude methanol extract and the isolated constituents exhibit antimycobacterial activities (MIC 83.3−107.7 μM) against the H37Rv strain of Mycobacterium tuberculosis. Compounds 1, 3, 4, and 5 are cytotoxic (ED50 15.3−105.7 μM) against the MDA-MB-231 triple negative aggressive breast cancer cel…
Control of Murine Cytomegalovirus Infection by γδ T Cells
2015
Infections with cytomegalovirus (CMV) can cause severe disease in immunosuppressed patients and infected newborns. Innate as well as cellular and humoral adaptive immune effector functions contribute to the control of CMV in immunocompetent individuals. None of the innate or adaptive immune functions are essential for virus control, however. Expansion of γδ T cells has been observed during human CMV (HCMV) infection in the fetus and in transplant patients with HCMV reactivation but the protective function of γδ T cells under these conditions remains unclear. Here we show for murine CMV (MCMV) infections that mice that lack CD8 and CD4 αβ-T cells as well as B lymphocytes can control a MCMV i…
The Value of Median Nerve Sonography as a Predictor for Short- and Long-Term Clinical Outcomes in Patients with Carpal Tunnel Syndrome: A Prospective…
2016
Objectives To investigate the prognostic value of B-mode and Power Doppler (PD) ultrasound of the median nerve for the short- and long-term clinical outcomes of patients with carpal tunnel syndrome (CTS). Methods Prospective study of 135 patients with suspected CTS seen 3 times: at baseline, then at short-term (3 months) and long-term (15–36 months) follow-up. At baseline, the cross-sectional area (CSA) of the median nerve was measured with ultrasound at 4 levels on the forearm and wrist. PD signals were graded semi-quantitatively (0–3). Clinical outcomes were evaluated at each visit with the Boston Questionnaire (BQ) and the DASH Questionnaire, as well as visual analogue scales for the pat…
Mutant HRAS as novel target for MEK and mTOR inhibitors.
2015
HRAS is a frequently mutated oncogene in cancer. However, mutant HRAS as drug target has not been investigated so far. Here, we show that mutant HRAS hyperactivates the RAS and the mTOR pathway in various cancer cell lines including lung, bladder and esophageal cancer. HRAS mutation sensitized toward growth inhibition by the MEK inhibitors AZD6244, MEK162 and PD0325901. Further, we found that MEK inhibitors induce apoptosis in mutant HRAS cell lines but not in cell lines lacking RAS mutations. In addition, knockdown of HRAS by siRNA blocked cell growth in mutant HRAS cell lines. Inhibition of the PI3K pathway alone or in combination with MEK inhibitors did not alter signaling nor had an imp…
Cytotoxic effects of Jay Amin hydroxamic acid (JAHA), a ferrocene-based class I histone deacetylase inhibitor, on triple-negative MDA-MB231 breast ca…
2012
The histone deacetylase inhibitors (HDACis) are a class of chemically heterogeneous anticancer agents of which suberoylanilide hydroxamic acid (SAHA) is a prototypical member. SAHA derivatives may be obtained by three-dimensional manipulation of SAHA aryl cap, such as the incorporation of a ferrocene unit like that present in Jay Amin hydroxamic acid (JAHA) and homo-JAHA [ Spencer , et al. ( 2011 ) ACS Med. Chem. Lett. 2 , 358 - 362 ]. These metal-based SAHA analogues have been tested for their cytotoxic activity toward triple-negative MDA-MB231 breast cancer cells. The results obtained indicate that of the two compounds tested, only JAHA was prominently active on breast cancer cells with a…