Gradual Inhibition Research Articles

P16Ink4a-induced senescence in cultured mast cells as a model for ageing reveals significant morphological and functional changes.

Mast cells (MCs) are tissue resident cells of the immune system, mainly known for their role in allergy. However, mounting evidence indicates their involvement in the pathology of age-related diseases, such as Alzheimer's disease, Parkinson's disease, and cancer. MC numbers increase in aged tissues, but how ageing affects MCs is poorly understood. We show that MC ageing is associated with the increased expression of the cell cycle inhibitor p16 Ink4a, a marker and inducer of cellular senescence. Relying on this observation and the tight association of ageing with senescence, we developed a model of inducible senescence based on doxycycline-induced expression of p16Ink4a in cultured bone marrow derived MCs (BMMCs). Using this model, we show that senescent MCs upregulate IL-1β, TNF-α and VEGF-A. We also demonstrate that senescence causes marked morphological changes that impact MC function. Senescent MCs are larger, contain a larger number of secretory granules (SGs) and have less membrane protrusions. Particularly striking are the changes in their SGs, reflected in a significant reduction in the number of electron dense SGs with a concomitant increase in lucent SGs containing intraluminal vesicles. The changes in SG morphology are accompanied by changes in MC degranulation, including a significant increase in receptor-triggered release of CD63-positive extracellular vesicles (EVs) and the exteriorisation of proteoglycans, as opposed to a gradual inhibition of the release of β-hexosaminidase. The inducible expression of p16Ink4a imposes MC senescence, providing a model for tracking the autonomous changes that occur in MCs during ageing. These changes include both morphological and functional alterations. In particular, the increased release of small EVs by senescent MCs suggests an enhanced ability to modulate neighbouring cells.

Individual and combined effects of ionophore antibiotics monensin and lasalocid on growth, oxidative stress and antioxidant responses of Microcystis aeruginosa

ABSTRACT To assess the impact of monensin, lasalocid, and a 1:1 (w/w) mixture of monensin and lasalocid on the formation of Microcystis aeruginosa-based harmful algal blooms (HABs), laboratory experiments were conducted [temperature 20 ± 1°C, illumination PAR 30 ± 4 μmol/m2 ·s (12-h light/dark cycle), growth medium BG-11] at concentrations of 100, 200, 500, 1,000, and 2,000 μg/L. Measurements included optical density, cell protein content, chlorophyll ‘a’ (Chl. a) content, oxidative stress, catalase activity (CAT), and guaiacol peroxidase activity (GPX). Monensin treatment showed a dose-dependent positive effect on M. aeruginosa growth at concentrations ≤500 μg/L and a gradual dose-dependent growth inhibition at concentrations of 1,000 and 2,000 μg/L. The results indicated that monensin has a significant positive effect on the formation of HABs by M. aeruginosa. Lasalocid treatment showed a growth reduction of M. aeruginosa at concentrations ≤500 μg/L and a growth increase at higher concentrations (1,000 and 2,000 μg/L). The monensin and lasalocid 1:1 (w/w) mixture test showed an intermediate response, as indicated by the individual treatments signifying the potential interactive effects of these antibiotics on the growth of M. aeruginosa. Furthermore, alterations in Chl. ‘a’, oxidative stress, CAT, and GPX measurements provided evidence of the impact of these antibiotics on the existence of M. aeruginosa.

Molecular response and adaptation mechanism of Microcystis aeruginosa under metalimnetic oxygen minimum conditions

Reservoirs are important drinking water sources. The metalimnetic oxygen minimum (MOM) usually occurs periodically in summer and autumn in deep-water reservoirs due to algae blooms and thermal stratification. This study aimed to explore the physiological and molecular responses of Microcystis aeruginosa (M. aeruginosa) under MOM conditions (darkness coupled with low dissolved oxygen (DO) concentration, hydrostatic pressure, and nutrient starvation). The comprehensive response of M. aeruginosa suggested that MOM conditions led to an immediate collapse of gas vesicles. This was followed by a gradual inhibition of photosynthesis by disturbing the electron transport chain and a significant downregulation of energy metabolism and carbohydrate metabolism. The active cells were approximately 5 % and > 45 % under MOM aerobic (3.0–7.0 mg/L DO) and anaerobic conditions (< 0.5 mg/L DO), respectively, for 20 days. In addition, a single exposure to darkness or pressure accelerated the decay of M. aeruginosa cells; however, MOM conditions with a low DO concentration had the opposite effect. The survival of M. aeruginosa cells under MOM conditions could be attributed to stringent response and the activation of HIF-1 signal when DO concentration decreased to < 2.0 mg/L by promoting the formation of cellular quiescence and resource redistribution. This study sheds light on the molecular response and adaptation mechanism of M. aeruginosa under MOM conditions.

Radical n-p Conduction Switching and Significant Photoconductivity Enhancement in NbOI2 via Pressure-Modulated Peierls Distortion.

The absence of intrinsic p-type 2D layered semiconductors has hampered the development of 2D devices, particularly in complementary metal-oxide-semiconductor (CMOS) devices and integrated circuits. Developing practical p-type semiconductors and advanced modulation techniques for precise carrier control is paramount to advancing electronic devices and systems. Here, by applying pressure to continuously tune the Peierls distortion in NbOI2, we effectively control the polarity and concentration of carriers and significantly enhance its photoelectric properties. The results demonstrate that by suppressing the off-center displacement of Nb atoms along the in-plane b direction under pressure, NbOI2 undergoes a semiconductor-to-semiconductor phase transition from C2 to C2/m, leading to a significant transition from n-type to p-type carrier behavior. Additionally, the gradual inhibition of internal interactions within Nb-Nb dimers along the in-plane c direction under high pressure facilitates electron delocalization, substantially enhancing the photoelectric properties. The photocurrent is increased by more than 3 orders of magnitude under xenon irradiation, and the spectral response range is continuously red-shifted and extended to 1450 nm. These findings highlight the potential of pressure engineering to adjust photoelectric properties effectively and flexibly, offering valuable insights for designing high-performance p-type two-dimensional semiconductors.

Chronic toxic effects of erythromycin and its photodegradation products on microalgae Chlorella pyrenoidosa

The photodegradation products (PDPs) of antibiotics in the aquatic environment received increasing concern, but their chronic effects on microalgae remain unclear. This study initially focused on examining the acute effects of erythromycin (ERY), then explored the chronic impacts of ERY PDPs on Chlorella pyrenoidosa. ERY of 4.0 − 32 mg/L ERY notably inhibited the cell growth and chlorophyll synthesis. The determined 96 h median effective concentration of ERY to C. pyrenoidosa was 11.78 mg/L. Higher concentrations of ERY induced more serious oxidative damage, antioxidant enzymes alleviated the oxidative stress. 6 PDPs (PDP749, PDP747, PDP719, PDP715, PDP701 and PDP557) were identified in the photodegradation process of ERY. The predicted combined toxicity of PDPs increased in the first 3 h, then decreased. Chronic exposure showed a gradual decreasing inhibition on microalgae growth and chlorophyll content. The acute effect of ERY PDPs manifested as growth stimulation, but the chronic effect manifested as growth inhibition. The malonaldehyde contents decreased with the degradation time of ERY at 7, 14 and 21 d. However, the malonaldehyde contents of ERY PDPs treatments were elevated compared to those in the control group after 21 d. Risk assessment still need to consider the potential toxicity of degradation products under long-term exposure.

A comprehensive model for the biochemistry of ageing, senescence and longevity.

Various models for ageing, each focussing on different biochemical and/or cellular pathways have been proposed. This has resulted in a complex and non-coherent portrayal of ageing. Here, we describe a concise and comprehensive model for the biochemistry of ageing consisting of three interacting signalling hubs. These are the nuclear factor kappa B complex (NFκB), controlling the innate immune system, the mammalian target for rapamycin complex, controlling cell growth, and the integrated stress responses, controlling homeostasis. This model provides a framework for most other, more detailed, biochemical pathways involved in ageing, and explains why ageing involves chronic inflammation, cellular senescence, and vulnerability to environmental stress, while starting with the spontaneous formation of advanced glycation end products. The totality of data underlying this model suggest that the gradual inhibition of the AMPK-ISR probably determines the maximal lifespan. Based on this model, anti-ageing drugs in general, are expected to show hormetic dose response curves. This complicates the process of dose-optimization. Due to its specific mechanism of action, the anti-aging drug alkaline phosphatase is an exception to this rule, because it probably exhibits saturation kinetics.

Hydrostatic pressure impedes the degradation of sinking copepod carcasses and fecal pellets.

Fast-sinking zooplankton carcasses and fecal pellets appear to contribute significantly to the vertical transport of particulate organic carbon (POC), partly because of low temperature that decreases microbial degradation during the descent into the deep ocean. Increasing hydrostatic pressure could further reduce the degradation efficiency of sinking POC, but this effect remains unexplored. Here, the degradation of carcasses and fecal pellets of the abundant marine copepod Calanus finmarchicus was experimentally studied as a function of pressure (0.1-100MPa). Samples were either exposed to elevated pressure in short 1-day incubations or a gradual pressure increase, simulating continuous particle sinking during a 20-day incubation. Both experiments revealed gradual inhibition of microbial respiration in the pressure range of 20-100MPa, corresponding to 2-10-km depth. This suggests that hydrostatic pressure impedes carbon mineralization of fast-sinking carcasses and fecal pellets and enhances the deep-sea deposition rate of zooplankton-derived organic material.

Poly-3-hydroxybutyrate-co-3-hydroxyvalerate(PHBV)-Polyethylene glycol 20k(PEG20k) as a promising delivery system for PT2399 in the treatment of disc degeneration.

Disc degeneration often leads to a highly prevalent symptom known as low back pain. Healthy nucleus pulposus tissue exhibited a hypoxic environment devoid of blood vessels, while degenerated nucleus pulposus experienced hypoxic deterioration and the formation of new blood vessels. In this study, the expression of important genes like HIF-2α was found to vary between normal and degenerated nucleus pulposus cells when compared to the hypoxic surroundings. The aim of this study was to examine how HIF-2α is controlled in nucleus pulposus cells under hypoxic conditions and its role in angiogenic mechanisms. To assess the impact of gradual inhibition of HIF-2α on disc degeneration, we utilized PHBV-based synthetic materials loaded with inhibitors of HIF-2α. Specifically, we employed LPS and PT2399 loaded PHBV-PEG20k (PP20) to intervene with human nucleus pulposus cells. Additionally, we treated APD rat models with PT2399 loaded PP20 to evaluate its effects. The expression levels of target markers in nucleus pulposus cells were detected using PCR, WB, and immunofluorescence. Additionally, the effect of drugs on disc degeneration was identified through HE staining. The findings indicated that HIF-2α, CAIX, PPP1R15A, VEGFA, and EGLN3 could potentially serve as new indicators of disc degeneration. Additionally, HIF-2α might contribute to the progression of disc degeneration through involvement in angiogenesis and the regulation of hypoxia. Furthermore, the utilization of PT2399 loaded PHBV-PEG20k (PP20) could potentially offer a fresh alternative for treating disc degeneration.

In Ukrainian

The work is devoted to the investigation of the morphology and adsorption properties of powder composites based on biogenic hydroxyapatite modified by magnetite (1, 5, 25, 50 wt. %) of various types (synthesis methods) and chitosan. The morphology of the powders evaluated using SEM micrographs and AMIS software is characterized by a uniform distribution of particles size and shape. It was established that the use of magnetite synthesized by chemical precipitation in the amount of 1-5% allows to obtain composite materials with a particle size in a narrower size range. Analysis of the kinetics of adsorption-desorption processes showed that the adsorption of water vapor is directly related to the ratio of hydroxyapatite and magnetite, increasing with increasing magnetite content. In addition, it is shown that the adsorption process for composites modified by magnetite obtained by the chemical precipitation method proceeds uniformly, while for composites containing magnetite obtained by the thermal decomposition method, three consecutive stages of the adsorption process are characteristic: rapid linear increase in mass, gradual inhibition of the adsorption process and stabilization of the mass of the material. The evaluation of the increase in mass also indicates a connection with the ratio of hydroxyapatite and magnetite, increasing with increasing magnetite content, which confirms the presence of physicochemical processes of interaction of gas molecules with the active centers of the molecules of the studied materials. DTGA also shows that the type of magnetite in an amount of more than 25% significantly affects the mass loss of composites during heat treatment up to 1000 °C, which is related to the initial characteristics of the magnetite used. The presented results in combination with previously obtained physicomechanical and biochemical properties testify to the prospects of biogenic hydroxyapatite/magnetite/chitosan composite materials for medicine.

Assessment of the effect of heavy metals on the imbalance of growth processes

Purpose. To determine the phytotoxic properties of model solutions of heavy metals (Cd, Pb, Ni, Cu) on the growth of roots and sprouts of the test plants of oats Avena sativa L. as a representative of monocotyledonous cereals and radish Raphanus sativus L. as a representative of dicotyledonous broad-leaved plants. Methods. Statistical, model solutions, test plants, biotesting. Results. As a result of phytotoxicity of model solutions of heavy metals Cd, Pb, Ni, Cu on Avena sativa L. test plants, it was established that there is no imbalance of growth processes when using solutions with concentrations of 1 MPC and 5 MPC. With an increase in the concentration of model solutions, there is a gradual inhibition of the growth of sprouts and especially the roots of the test objects. The most toxic effect on the test object, according to the research results, was caused by Cd - a phytotoxic effect from weak to strong was observed under the influence of different concentrations of model solutions. Experimental determination of the phytotoxic properties of model solutions of heavy metals Cd, Pb, Ni, Cu on test plants Raphanus sativus L. showed that the imbalance of growth processes is absent only when using solutions with concentrations of 1 MPC and 5 MPC Cu, i.e. practically without exceeding the regulatory requirements for soil quality. Model solutions of Cd and Cu 40 MPC had the highest degree of imbalance in the growth processes of the test plants Raphanus sativus L. – strong for the experimental study we conducted. Conclusions. Biodiagnostics using Raphanus sativus L. test plants revealed signs of toxic effects where Avena sativa L. test plants did not experience inhibition, or the determined phytotoxic properties of the model solutions were lower, which is determined by the imbalance of growth processes. The above-mentioned discrepancies between the results of biodiagnostics of model solutions with the help of different test cultures make it possible to assert that it is necessary to introduce a comprehensive indicator for determining the phytotoxic properties of the studied samples, with the help of which it is possible to level such discrepancies.

Epidemiology of gastrointestinal bleedings compared in Ukraine and in the Poltava region

Acute gastrointestinal bleeding was and remains one of the severe emergency surgical diseases both in Ukraine and in other countries. The study of epidemiology, namely of the prevalence of gastrointestinal bleedings is relevant and will allow to intensify the diagnostic stage and create clearer algorithms for the treatment of this pathology. The aim of the work was to study the dynamics of emergency medical care for patients with gastrointestinal bleedings in Ukraine and the Poltava region. A statistical retrospective study of indicators of emergency medical care for patients with gastrointestinal bleedings in Ukraine and the Poltava region was conducted using data from official sources of the Center for Medical Statistics of the Ministry of Health of Ukraine. The wave-like nature of the increase in hospitalization of patients with gastrointestinal bleedings was observed in Ukraine and the Poltava region. The growth rates obtained as a result of the alignment of the dynamic series gave a clear trend towards the acceleration of the decline of this indicator: from -1.25 to -1.36 in Ukraine; and in the Poltava region before increasing the rate: from 4.85 to 3.62. During the entire studied period, the average level of hospitalization of patients with gastrointestinal bleeding after 24 hours was consistently higher in the Poltava region than in Ukraine (in Ukraine – 36.13% versus 43.16% in the Poltava region) (р&lt;0.05). The rate of postoperative mortality in these patients in Ukraine increased (from 5.02% to 6.30%) (р&lt;0.05)with gradual inhibition (the growth rate decreased). In the Poltava region, the level of the indicator exceeded the national level and the leveling of the dynamic series had a downward trend (from 12.4% to 10.38%) (р&lt;0.05). Thus, the problem of gastrointestinal bleeding remains relevant at the present time, as it continues to remain one of the severe urgent surgical diseases, both in Ukraine as a whole and in its individual regions, in particular in the Poltava region. Peptic ulcer disease of the stomach and duodenum continues to remain the first nosology that causes gastrointestinal bleeding. Postoperative mortality remains high and ranges from 5% to 12%. The time of hospitalization from the onset of the disease to hospitalization is consistently higher in the Poltava region than in Ukraine (the average level in Ukraine is 36.13% versus 43.16% in Poltava region) (р&lt;0.05).

Cytotoxic, anti-proliferative, and apoptotic evaluation of Ramalina sinensis (Ascomycota, Lecanoromycetes), lichenized fungus on oral squamous cell carcinoma cell line; in-vitro study

BackgroundScientists and medical professionals are actively striving to improve the efficacy of treatment methods for oral squamous cell carcinoma (OSCC), the most frequently occurring cancer within the oral cavity, by exploring the potential of natural products. The active pharmacological compounds found in lichenized fungi have shown potential for aiding in cancer treatment. Recent research aims to evaluate the impact of the lichenized fungus Ramalina sinensis (R. sinensis) on the cell viability and apoptosis of OSCC cell lines, considering the anti-inflammatory and anti-cancer capabilities of lichens.MethodsRamalina sinensis (Ascomycota, Lecanoromycetes) was selected for investigation of its effects on a human oral squamous cell carcinoma cell line. Acetone and methanol extracts of R. sinensis on an OSCC cell line (KB cell line, NCBI Code: C152) were investigated. Viability was assessed by MTT assay analysis, and apoptotic cells were measured using flow cytometry analysis. Scratch assay was used to assess cell migration. The chemical composition and metabolic profiling of R. sinensis were investigated.ResultsThe growth and multiplication of KB cells were observed to undergo a gradual but remarkable inhibition when exposed to various concentrations. Specifically, concentrations of 6.25, 12.5, 25, 50, 100, and 200 μg/mL exhibited a significant suppressive effect on the proliferation of KB cells. The inhibition of cell proliferation exhibited a statistically significant difference between the extracts obtained from acetone and methanol. Flow cytometry results show an increase in apoptosis of OSCC cells by acetone extract. R. sinensis exerted a concentration-dependent inhibitory effect on the migration of OSCC cells. The chemical composition of R. sinensis was investigated using liquid chromatography positive ion electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS), and 33 compounds in the acetone and methanol extracts of R. sinensis were detected.ConclusionThe findings provide evidence supporting the beneficial effects of R. sinensis extract on inducing apoptosis in OSCC cells and exerting anti-cancer properties.

Novel fluorescein isothiocyanate (FITC) cored PAMAM dendrimers as drug delivery agent

Fluorescent dyes, or fluorophores, enable researchers to visualize specific biological molecules by fluorescence microscopy. Herein, a novel fluorescent FITC-poly(amidoamine) (FITC-PAMAM) dendrimers have been synthesized via divergent approach. The molecular structure of the FITC-PAMAM dendrimers (G-0 to G5) was characterized by 1H NMR, 13C NMR spectroscopy and by FTIR. In order to emphasize the structural efficacy of FITC-PAMAM dendrimer, the drug delivery behavior has been evaluated by using 5-fluorouracil (5-FU) as a model cancer therapy drug. Anti-proliferative activity of FITC-cored PAMAM dendrimers in all generations (G0-G5) with or without 5-FU were analyzed on human gastric carcinoma cells (AGS) by WST-1 cell proliferation assay. Initially, the nontoxic dose of unloaded FITC-PAMAM dendrimers was assessed for further drug loading experiments. Loading of 5-FU into FITC-PAMAM dendrimers, regardless of generation, increased the toxicity of the drug. Besides, 5-FU loaded FITC-PAMAM dendrimers induced a generation-based gradual inhibition of cell proliferation. FITC and phase contrast merged images indicated that FITC-PAMAM dendrimers facilitate the entry of the drug into the cells, in a generation-dependent manner. The FITC- dendrimers may serve as a promising intracellular drug delivery agent for 5-FU by increasing cell uptake into cells and thereby, enhancing antiproliferative activity on AGS cells in a generation-dependent manner.

Isolation of alkaloidal and glycosidal fractions from leaves of Trigonella foenum-graecum L. cv. Desi indigenous to Pakistan for antiprostaglandin evaluation as substitute of nonsteroidal anti-inflammatory drugs

Ethnopharmacological relevanceTrigonella foenum graecum (fenugreek) has been in use for a long time as a traditional medicine and natural food additive. The reported gastro-protective property makes it unique among other herbs. Seeds and leaves have been shown to exert significant antiatherogenic, antidiabetic, antianorexic, antioxidant, anticarcinogenic, antihyperlipidemic, galactogogue and anti-inflammatory effects in several animal and human models. But its use as a substitute for ulcerative nonsteroidal anti-inflammatory drugs needs to be confirmed. Aim of the studyNonsteroidal anti-inflammatory drugs (NSAIDs) are in common use in treating inflammation associated with a variety of ailments, fever and pain such as menstrual cramps, back pain, arthritic pain and headaches. Their toxicity profile includes the risk of severe gastro-intestinal adverse events like increased bleeding tendency, ulceration, perforation, etc. Conventional NSAIDs have also been reported to reduce the glomerular filtration rate (GFR) by affecting afferent arterioles in nephrons. Exacerbated potassium levels were noted in patients using NSAIDs concomitantly with antihypertensive drugs belonging to the angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) classes. In this context, the need of the hour is to discover and isolate new compounds from the reported medicinal plants for evaluation of antiprostaglandin potential and safety profile in terms of the hepato-renal system. These compounds may be used as substitutes for NSAIDs in the future management of inflammation and pain with therapeutic equivalency and organ safety. In this scenario, the present study aimed to assess the antiprostaglandin potential of alkaloidal and glycosidal fractions from the leaves of Trigonella foenum-graecum L. cv. Desi variety, indigenous to Pakistan, in albino mice along with safety profile. The herb has been used as folk medicine since ancient times for treating inflammation and pain. Material and methodsAlkaloidal and glycosidal fractions were separated from a methanol extract of leaves of the fenugreek Desi variety. After separation of fractions, their subsiding effects on carrageenan-induced inflammation, air pouch exudate prostaglandin-E2 levels, Brewer's yeast induced pyrexia and acetic acid induced abdominal constrictions were assessed in adult male albino mice. The safety profile of fractions was assessed by measuring their effects on mice sera hepato-renal biomarkers. ResultAlkaloidal fraction of T. foenum Desi variety was found to be significantly effective in reducing inflammation, air pouch exudate PGE2 levels, fever (≤37 °C) and pain by inhibiting writhes (up to 96.58%) Gradual inhibition of paw edema was observed 1–6 h post-dose, with maximum reduction percentages of 62.82% and 62.57% for 100 mg and 200 mg, respectively. Both fractions did not disturb the normal physiology of the hepato-renal system by showing normal biomarker values. ConclusionIn summary, the results demonstrate the potent antiprostaglandin potential of the alkaloidal fraction of gastroprotective fenugreek “Desi” leaves with hepato-renal system safety and hence justify its use as a substitute for ulcerative nonsteroidal anti-inflammatory drugs.

Effect of Aqueous Leaf Extract of Eucalyptus globulus Labill. on Seed Germination of Chickpea

The present study has been done to investigate the effect of aqueous leaf extract of Eucalyptus globulus on seed germination and rate of radicle growth of Chickpea under laboratory conditions. The study found complete inhibition of seed germination under the treatment of concentrated raw extract (14.28gm/100 ml) and its different dilutions (viz-90%, 70%, 50%, 30% &amp; 10%). Later, a much-diluted raw extract (5.26gm/100ml) was made with its different dilutions as above to study germinations. Later case showed a gradual inhibition in radicle growth with the increasing concentration with a correlation coefficient (r=0.72).

Chemical Derivatization and Characterization of Novel Antitrypanosomals for African Trypanosomiasis.

The search for novel antitrypanosomals and the investigation into their mode of action remain crucial due to the toxicity and resistance of commercially available antitrypanosomal drugs. In this study, two novel antitrypanosomals, tortodofuordioxamide (compound 2) and tortodofuorpyramide (compound 3), were chemically derived from the natural N-alkylamide tortozanthoxylamide (compound 1) through structural modification. The chemical structures of these compounds were confirmed through spectrometric and spectroscopic analysis, and their in vitro efficacy and possible mechanisms of action were, subsequently, investigated in Trypanosoma brucei (T. brucei), one of the causative species of African trypanosomiasis (AT). The novel compounds 2 and 3 displayed significant antitrypanosomal potencies in terms of half-maximal effective concentrations (EC50) and selectivity indices (SI) (compound 1, EC50 = 7.3 μM, SI = 29.5; compound 2, EC50 = 3.2 μM, SI = 91.3; compound 3, EC50 = 4.5 μM, SI = 69.9). Microscopic analysis indicated that at the EC50 values, the compounds resulted in the coiling and clumping of parasite subpopulations without significantly affecting the normal ratio of nuclei to kinetoplasts. In contrast to the animal antitrypanosomal drug diminazene, compounds 1, 2 and 3 exhibited antioxidant absorbance properties comparable to the standard antioxidant Trolox (Trolox, 0.11 A; diminazene, 0.50 A; compound 1, 0.10 A; compound 2, 0.09 A; compound 3, 0.11 A). The analysis of growth kinetics suggested that the compounds exhibited a relatively gradual but consistent growth inhibition of T. brucei at different concentrations. The results suggest that further pharmacological optimization of compounds 2 and 3 may facilitate their development into novel AT chemotherapy.

P008 Store-operated calcium entry controls immune cell function and activation in Inflammatory Bowel Disease

Abstract Background Inflammatory bowel disease (IBD) comprises ulcerative colitis (UC) and Crohn’s disease (CD), both representing major clinical challenges in need of new treatment modalities to improve patient care. Store-operated calcium entry (SOCE) is the predominant calcium influx pathway in immune cells regulating many of their functional properties. Conditional knockout mice, in which SOCE signaling components are deleted in T cells, have revealed that SOCE is required for the induction of intestinal inflammation in mouse models of colitis. However, it is currently unknown whether the pharmacologic inhibition of SOCE is a suitable drug target in IBD and it remains elusive, which immune cell subsets are affected by the pharmaceutical blockade of SOCE. Therefore, we here aimed to investigate the effects of the SOCE inhibitor BTP-2 on the function and activation of lymphocytes isolated from IBD patients. Methods PBMC and/or lamina propria lymphocytes (LPMC) were isolated from UC and CD patients undergoing colon resection. Cells were ex -vivo stimulated with PMA/Ionomycin in the presence or absence of increasing concentrations of BTP-2, fixed and stored at -80°C until acquisition by mass cytometry. LPMCs were stained using 37 lineage and functional markers targeting B, T, NK or myeloid cells and the resulting flow cytometry standard (FCS) files were analyzed by using cytobank and the R/Bioconductor 9 packages. Additionally, Ca2+ influx measurements were performed in order to assess the impact of SOCE inhibition on the calcium homeostasis of various immune cell subsets. Results Data on B, T, NK, and myeloid cells revealed that treatment with BTP-2 causes a dose-dependent inhibition of calcium influx, demonstrating that BTP-2 is a potent inhibitor of SOCE in human LPMCs and PBMCs. By applying mass cytometry, we investigated how the gradual pharmacologic inhibition of SOCE affects the activation and pro-inflammatory functions of various immune cell subsets obtained from colon specimens of patients with UC and CD, which were characterized by the accumulation of CD4+ effector T cells, IFNγ-producing CD8+ T cells and IL-17-producing innate lymphoid cells (ILCs) compared to non-inflamed specimens. Remarkably, inhibition of SOCE attenuated the production of cytokines including IL-2, IL-4, IL-6, IL-17, TNF-α and IFNγ by T cells and ILCs, reduced the activation of B cells and decreased the production of IFNγ by myeloid cells without affecting the viability of primary human epithelial cells. Conclusion Our data reveal for the first time that the cytokine production and the activation of several immune cell subtypes can be modulated by SOCE blockade in human intestinal inflammation, identifying SOCE as a novel therapeutic target in colitis.

Effects of memantine and its metabolite Mrz 2/373 on soman-induced inhibition of acetylcholinesterase in vitro

Memantine is the non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, used in the treatment of Alzheimer's disease. It is also known that memantine pretreatment assured protection of skeletal muscles from poisoning with nerve agents and an interaction between memantine and AChE was proposed. In the study presented we examined interactions of memantine and its main metabolite (1-amino-3-hydroxymethyl-5-methyl adamantine, Mrz 2/373) with AChE in vitro as well as their effect on kinetics of the soman-induced AChE inhibition and aging. The results have shown that memantine and Mrz 2/373 exerted concentration-dependent inhibition of AChE, with Mrz 2/373 being a more potent inhibitor than the parent compound. Addition of soman 7.5 nmol/l induced gradual AChE inhibition that became almost complete after 20 min. Memantine (0.1, 0.5 and 1 mmol/l) and Mrz 2/373 (0.1, 0.5 and 1 mmol/l) concentration-dependently slowed down the AChE inhibition. After 30 min of incubation of AChE with soman, 5 min of aging and 20 min of reactivation by asoxime (HI-6 dichloride), AChE activity was 8.1% in control medium, 30.7% and 41.9% after addition of 1 and 10 mmol/l memantine, and 16.1% after addition of 1 mmol/l Mrz 2/373. It was concluded that it is possible that memantine and Mrz 2/373 can prevent AChE from inhibition by soman, which could, along with known memantine's neuroprotective activity, explain its potent antidotal effect in soman poisoning. The potential effect on aging of the soman-AChE complex warrants further studies.

Multi-Level Switching of Al-Doped HfO2 RRAM with a Single Voltage Amplitude Set Pulse

In this paper, the resistive switching characteristics in a Ti/HfO2: Al/Pt sandwiched structure are investigated for gradual conductance tuning inherent functions. The variation in conductance of the device under different amplitudes and voltage pulse widths is studied. At the same time, it was found that the variation in switching parameters in resistive random-access memory (RRAM) under impulse response is impacted by the initial conductance states. The device was brought to a preset resistance value range by energizing a single voltage amplitude pulse with a different number of periodicities. This is an efficient and simple programming algorithm to simulate the strength change observed in biological synapses. It exhibited an on/off of about 100, an endurance of over 500 cycles, and a lifetime (at 85 °C) of around 105 s. This multi-level switching two-terminal device can be used for neuromorphic applications to simulate the gradual potentiation (increasing conductance) and inhibition (decreasing conductance) in an artificial synapse.

Short exposure of Artemia salina to group-12 metals: Comparing hatchability, mortality, lipid peroxidation, and swimming speed

The hatchability, mortality rate, lipid peroxide levels, and swimming speed of Artemia salina have been compared based on short exposures of ZnCl2, CdCl2, and HgCl2 in artificial seawater. The hatching tests were carried out for 12, 24, 36, and 48 h at 28 °C. Mortality rate and lipid peroxide (LPO) levels were determined after 24 h of exposure at 28 °C, in the dark, and on living larvae using the FOX method. The swimming speed was determined after 24 h using a microcomputer coupled to a digital camera, with simultaneous treatment of the recorded images every 25 s, at 25 °C, under red-light irradiation. Results showed that Zn caused a gradual inhibition of the hatching for concentrations <900 µmol L−1; however, Cd and Hg displayed almost complete inhibition for concentrations ≤100 µmol L−1. Also, the heavy metals caused a dose-dependent increase of mortality (LD50) in the following order: Zn = 3290 µmol L−1 < Cd = 2206 µmol L−1 < Hg = 15.6 µmol L−1. Furthermore, significant LPO levels were found for Cd (1500–2000 µmol L−1, p < 0.001) and Hg (5–20 µmol L−1, p < 0.001). Finally, the swimming speed values increased significantly, for Zn ≈ 2.5 mm s−1 (1500 µmol L−1, p < 0.001), Cd ≈ 3.5 mm s−1 (2000 µmol L−1, p < 0.05), and Hg ≈ 4.0 mm s−1 (15 µmol L−1, p < 0.05), after 24 h exposure. There is a clear dose-dependent toxicity, indicating that Zn, Cd and Hg can induce significant changes in hatchability, mortality, and ethological and biochemical parameters.