Dose-responsive Way Research Articles

FNF-12, a novel benzylidene-chromanone derivative, attenuates inflammatory response in in vitro and in vivo asthma models mediated by M2-related Th2 cytokines via MAPK and NF-kB signaling.

This study evaluates a novel benzylidene-chromanone derivative, FNF-12, for efficacy in in vitro and in vivo asthma models. Rat basophilic leukemia (RBL-2H3) and acute monocytic leukemia (THP-1)-derived M2 macrophages were used. Human whole blood-derived neutrophils and basophils were employed. Flow cytometry was used for studying key signalling proteins. Platelet activation factor (PAF)-induced asthma model in guinea pigs was used for in vivo studies. The chemical structure of FNF-12 was confirmed with proton-nuclear mass resonance (NMR) and mass spectroscopy. FNF-12 controlled degranulation in RBL-2H3 cells with an IC50 value of 123.7nM and inhibited TNF-α release from these cells in a dose-responsive way. The compound effectively controlled the migration and elastase release in activated neutrophils. IC50 value in the FcεRI-basophil activation assay was found to be 205nM. FNF-12 controlled the release of lipopolysaccharide (LPS)-induced interleukin-10, I-309/CCL1 and MDC/CCL22 in THP-1 derived M2 macrophages. The compound suppressed LPS-induced mitogen activated protein kinase (MAPK)-p-p38 and nuclear factor kappa B(NF-kB)-p-p65 expression in these cells. A dose-dependent decrease in the accumulation of total leucocytes, eosinophils, neutrophils and macrophages was observed in PAF-induced animal models. FNF-12 was able to control the inflammatory responses in in vitro and in vivo asthma models, which may be driven by controlling M2-related Th2 cytokines via MAPK and NF-kB signaling.

Current Smoking Negatively Affects the Response to Methotrexate in Rheumatoid Arthritis in a Dose-responsive Way, Independently of Concomitant Prednisone Use.

Current smoking reduces clinical response to several disease-modifying antirheumatic drugs. It is unknown if this is also the case for prednisone. We aimed to determine whether current smoking affects the clinical response to concomitant prednisone in a methotrexate (MTX)-based treatment strategy. In the CAMERA-II trial (isrctn.com identifier: 70365169), patients with early rheumatoid arthritis (RA) initiated an MTX-based strategy and were randomized to concomitant prednisone (MTX + pred) or placebo (MTX + PBO) for 24 months. Linear mixed modeling was performed with Disease Activity Score assessing 28 joints (DAS28) as the dependent variable, and strategy group and current smoking status as independent variables, correcting for relevant covariates. The interaction between current smoking and strategy was tested to find out whether the effect of current smoking on clinical response was different between the strategy groups with prednisone or PBO. Current smoking was significantly associated with higher DAS28 over time (mean difference with nonsmokers 0.57 [95% CI 0.22-0.92, P < 0.01]). This association was not different between the strategy groups with prednisone or PBO (P = 0.73). The negative effect of current smoking on DAS28 was dose dependent. Current smoking in patients with early RA significantly reduces the clinical effect of an MTX-based strategy, independent of whether concomitant prednisone is used. This effect is dose dependent.

IOX-101, a novel small molecule, reduces AML cell proliferation by Akt enzyme inhibition

Cancer of the blood continues to be a major mortality factor globally. Arylidene compounds are well known for their anticancer effects. Here we describe the biological efficacy of IOX-101, a potential lead-compound of arylidene in acute myeloid leukemia (AML). Initially, molecular docking analysis was performed to check the binding efficacy of the compound with protein kinase B (Akt). The ability of the molecule to inhibit AML proliferation was assessed in THP-1 and Kasumi-6 cells by a standard MTT assay. Hoechst 333258/propidium iodide (PI) staining was carried out to analyze the nuclear damage. Flow cytometry was performed to check the apoptotic and cell cycle changes in THP-1 cells. The effect of IOX-101 on Akt phosphorylation was assessed by Western blot analysis. Molecular docking revealed interaction and binding of IOX-101 with the active site of Akt enzyme. The compound reduced proliferation of both AML cell lines in a dose-responsive way. Nuclear staining and cell cycle results revealed DNA damage by IOX-101 in THP-1 cells, and a significant increase in early and late phase apoptotic cells. A dose-dependent dephosphorylation of Akt (Ser 473) by IOX-101 was observed, which indicated allosteric inhibition of Akt by the compound. Our results showed that the DNA damage-mediated antiproliferative effect of IOX-101 in AML cells was mediated by Akt enzyme inhibition, and that this molecule possesses an effective chemotherapeutic potential against AML. https://doi.org/10.2298/ABS170922049R Received: September 22, 2017; Revised: November 1, 2017; Accepted: November 7, 2017; Published online: November 28, 2017 How to cite this article: Rajagopalan Prasanna, Raju M, Aseeri H, Helal IM, Elbessoumy AA. IOX-101, a novel small molecule, reduces AML cell proliferation by Akt enzyme inhibition. Arch Biol Sci. 2018;70(2):321-7.

BH4 treatment in BH4-responsive PKU patients: preliminary data on blood prolactin concentrations suggest increased cerebral dopamine concentrations

In phenylketonuria (PKU), cerebral neurotransmitter deficiencies have been suggested to contribute to brain dysfunction. Present treatment aims to reduce blood phenylalanine concentrations by a phenylalanine-restricted diet, while in some patients blood phenylalanine concentrations also respond to cofactor treatment with tetrahydrobiopterin (BH4). Recently, a repurposing approach of BH4 was suggested to increase cerebral neurotransmitter synthesis.To investigate whether BH4 may improve cerebral dopamine concentrations in PKU patients beyond its effect through lowering blood phenylalanine concentrations, we investigated blood prolactin concentrations—as a parameter of brain dopamine availability. We retrospectively compared blood prolactin in relation to blood phenylalanine concentrations of nine (male) BH4-responsive PKU patients, when being treated without and with BH4.Blood prolactin concentrations positively correlated to blood phenylalanine concentrations (p=0.002), being significantly lower with than without BH4 treatment (p=0.047). In addition, even in this small number of male patients, blood prolactin concentrations tended to be lower at increasing BH4 dose (p=0.054), while taking blood phenylalanine concentrations into account (p=0.002). In individual BH4-responsive patients, median blood prolactin concentrations were significantly lower while using BH4 than before using BH4 treatment (p=0.024), whereas median blood phenylalanine concentrations tended to be lower, but this did not reach statistical significance (p=0.107).Therefore, these data show that high blood phenylalanine in BH4-responsive PKU male patients seems to be associated with increased blood prolactin concentrations, suggesting reduced cerebral dopamine availability. Moreover, these data suggest that BH4 treatment in itself could decrease blood prolactin concentrations in a dose-responsive way, independent of blood phenylalanine concentrations. We conclude that these preliminary data indicate that BH4 treatment may improve cerebral dopamine concentrations in PKU patients beyond its effect through lowering blood phenylalanine concentrations, possibly in a dose-dependent manner, but further research would be warranted.

Processing technology changes in the Australian sheep meat industry: an overview

Over the last 20 years the Australian sheep industry, particularly the lamb meat sector, has undergone a major change in focus such that consumer requirements are a paramount determinant for production and processing developments. As a result automatic accurate methods of measuring carcasses for traits like fatness and meat yield have been important to aid a reduction by industry in carcass fat levels in line with domestic and international consumer demand. This occurred while carcass weight increased due to a range of genetic and production factors implemented on-farm. Further to this in the last 5–7 years there has been a dramatic increase in the adoption of electrical technologies based on new methodologies with a shift in focus onto eating quality. Underlying this new approach was the electrical stimulation of individual carcasses on segmented electrodes in a dose-responsive way with electricity that has short pulse widths and low to medium voltages and is thus much safer than the original high voltage systems. This technology allowed stimulation units to be fitted into abattoirs where this was not previously possible and validation showed that the technology could reduce toughness in lamb destined for the domestic market and some export markets. More recent technology to stretch and shape cuts shows promise for improving both the quality and product range from sheep and lamb carcasses. The industry continues to focus on meat quality and has shown a significant increase in exports, while maintaining per-capita domestic consumption at record retail prices. This indicates an industry where research investment across the board has shown significant returns.

Some important changes in the Australian sheep meat processing industry

In the last 5 years there has been a dramatic increase in the adoption in the Australian sheep meat processing industry of electrical technologies designed to streamline processing and improve product quality. Part of this change was initiated by an Australia-wide audit of lamb tenderness in 1997–98 and the development of a program to establish an eating quality scheme for sheep meat across Australia. Critically, these initiatives coincided with the development of new ways of administering electrical currents to either bodies or carcasses. Underlying this new approach is the electrocution of carcasses individually on segmented electrodes in a dose responsive way with electricity that has short pulse widths and lower voltages. This paper documents the pivotal factors which have contributed to this level of industry adoption and which has seen 14 abattoirs install the new technology. Of these abattoirs only one previously had any form of stimulation and these abattoirs represent more than 70% of the throughput of sheep and lambs on a tonnage basis per year in Australia.

Epidermal Growth Factor Receptor Expression in High-Grade Osteosarcomas Is Associated with a Good Clinical Outcome

The expression of the epidermal growth factor receptor (EGFR) in osteosarcomas has repeatedly been described. With the introduction of anti-EGFR-targeted therapies in clinical practice, these findings regain increased attention. Experience with anti-EGFR-targeted therapies in other cancers has made clear that besides the expression status of EGFR, a detailed knowledge about gene mutations is of major predictive power. We therefore aimed to explore the EGFR expression and gene mutation status in high-grade osteosarcomas. We investigated tumor samples of osteosarcoma patients of all age groups by means of immunohistochemistry (n=111) and egfr fluorescence in situ hybridization (n=39). Sixty-three patients were treated according to the Cooperative Osteosarcoma Study Group protocols and complete clinical follow-up was available in these cases. Ninety-one of 111 (81%) of osteosarcomas revealed an expression of EGFR. EGFR expression showed a dose-response relation with improved event-free and overall survival. This was independent of the degree of tumor regression due to neoadjuvant chemotherapy. Nine of 39 (23%) osteosarcomas showed egfr amplifications by means of fluorescence in situ hybridization. All these cases expressed EGFR. When comparing EGFR expression between primary biopsy and resection specimen (n=19), viable residual tumor cells in resection specimens revealed a lower EGFR expression and a tendency toward membranous staining compared with the initial biopsy. In conclusion, expression and amplification of EGFR are frequently observed in high-grade osteosarcomas and are associated with improved prognosis in a dose-responsive way. This implies that low EGFR expression possibly predicts lack of response to conventional treatment in high-grade osteosarcomas and may warrant a more intensive therapeutic approach, although not based on EGFR targeting.

Intrahepatic arterial infusion of chemotherapy: Pharmacologic principles

Hepatic arterial (HA) infusional chemotherapy possesses a number of constraints not found with systemic chemotherapy. The drug used should have activity in a dose-responsive way without significant hepatic toxicity. The drug must also possess suitable pharmacokinetic properties, namely, a high total body clearance and hepatic extraction, so as to generate high hepatic and low systemic exposures. Of the drugs examined for HA use, 5-fluoro-2'-deoxyuridine (FUDR, floxuridine) demonstrates the best properties. In HA infusional therapy, the catheter is positioned to deliver drug directly to the liver only and must be connected to a reliable pumping mechanism. Surgical implantation of catheters and pumps provides a safe and reliable means to infuse HA FUDR. HA FUDR delivery via an implanted system in the treatment of colorectal liver metastases represents the largest application of HA therapy and provides a basis for future advances when combined with other regional and systemic treatments. Semin Oncol 29:119-125. Copyright 2002, Elsevier Science (USA). All rights reserved.

DETECTION, CHARACTERISATION AND PURIFICATION OF A MURINE LIVER FACTOR CAPABLE OF DESENSITISING TOWARDS THE LETHAL ACTIVITY OF TUMOUR NECROSIS FACTOR

Tumour necrosis factor (TNF) is a major mediator in septic shock and several inflammatory diseases such as hepatitis. Galactosamine (GalN) sensitises experimental animals for TNF and the combination TNF/GalN leads to a lethal inflammatory hepatitis. We describe that a single injection of lipopolysaccharide (LPS), interleukin-1 (IL-1) or TNF can desensitise against the lethality induced by TNF/GalN, but also against changes in metabolic parameters such as hypothermia and transaminase release, in a dose responsive way. We also describe the desensitising capacity of a component present in Mouse Liver Extract (MLE). The MLE desensitises mice against the effects of TNF/GalN in a dose responsive way. The activity of the MLE is heat labile and does not involve LPS, TNF, IL-1 or TNF soluble receptors. We describe partial and complete purification of the factor. Partially pure material protects mice against all changes induced by TNF/GalN. The protection is dose dependent and heat labile and also possible in endotoxin-hyporesponsive C3H/HeJ mice. The pure material protects against lethality, hypothermia and AST release and it appears as a heat labile protein of relative molecular weight of 70kDa probably with a break down product of 35kDa.

Integrin alpha 3 beta 1 participates in the phagocytosis of extracellular matrix molecules by human breast cancer cells.

The mechanisms and receptors involved in phagocytosis by nonhematopoietic cells are not well understood. The involvement of the alpha 3 beta 1 integrin in phagocytosis of the extracellular matrix by human breast cancer cells was studied. The possible role of this integrin was suggested since alpha 3 and beta 1 but not alpha 2 subunits are concentrated at membrane sites where local degradation of fluorescently labeled gelatin occurs. Strikingly, anti-alpha 3 integrin monoclonal antibodies (mAbs) stimulate the phagocytosis of fluorescently labeled gelatin films, gelatin beads, and Matrigel films in a quantitative phagocytosis assay. Stimulation of the gelatin uptake by the anti-alpha 3 mAb is dose responsive, saturable, and time dependent. Antibodies against other integrin subunits have a lower stimulatory effect (anti-beta 1) or no significant effect (anti-alpha 2, -alpha 5, -alpha 6, and -alpha v) on gelatin phagocytosis. The synthetic HGD-6 human laminin peptide that binds specifically the alpha 3 beta 1 integrin, but not the scrambled HSGD-6 control peptide, also markedly stimulates gelatin uptake in a dose-responsive way. Furthermore, the stimulatory effects of the HGD-6 peptide and the anti-alpha 3 mAb are additive, suggesting that they might promote phagocytosis in different ways. Other laminin (YIGSR, IKVAV) and fibronectin (GRGDS) peptides have no effect on gelatin phagocytosis. Immunofluorescence shows that the alpha 3 and the beta 1, but not the alpha 2 integrin subunit, concentrate into patches on the cell surface after treatment with their respective mAbs. And, both gelatin and the alpha 3 beta 1 but not the alpha 2 beta 1 integrin are cointernalized and routed to acidic vesicles such as lysosomes. In conclusion, we demonstrate that human breast cancer cells locally degrade and phagocytose the extracellular matrix and show for the first time that the alpha 3 beta 1 integrin participates in this phagocytosis. We hypothesize that the anti-alpha 3 antibodies and the laminin peptide HGD-6 activate the alpha 3 beta 1 integrin, which results in a downstream signaling cascade stimulating phagocytosis.

Gangliosides have a bimodal effect on DNA synthesis in U-1242 MG human glioma cells.

GM1, GD1a, and GT1b inhibit both PDGF-stimulated and serum-stimulated DNA synthesis in Swiss 3T3 cells and the human glioma cell line U-1242 MG in a dose-dependent manner. The ganglioside inhibitory effect is counteracted in a dose-responsive fashion by serum such that ganglioside-induced inhibition is essentially abolished in 10% serum. Because of the potentially important role that gangliosides play in growth regulation of human gliomas, this phenomenon was studied in detail using U-1242 MG cells. Stimulation of DNA synthesis by low doses of serum in U-1242 MG cells is inhibited in a dose-responsive fashion by ganglioside GM1. However, serum itself counteracts the inhibitory effect of ganglioside in a dose responsive way. Kinetic analyses demonstrate that GM1 competes with some components of serum for sites on U-1242 MG cells (Kb of GM1 = 12.5 microM). On the other hand, GM1, GD1a, and GT1b stimulate DNA synthesis in quiescent U-1242 MG cells in both sparse and confluent conditions, indicating that ganglioside-stimulated DNA synthesis is dependent on the phase of cellular growth rather than cellular density. This growth stimulatory effect of gangliosides is more potent on quiescent, confluent cells than quiescent, sparse cells. These results demonstrate that exogenously added gangliosides can have opposite (bimodal) effects on progression of human glioma cells through the cell cycle depending upon the growth phase of the cells.

Hepatoprotective activity of carrot ( Daucus carota L.) against carbon tetrachloride intoxication in mouse liver

The effect of carrot extract on carbon tetrachloride (CCl 4)-induced acute liver damage was evaluated. The increased serum enzyme levels (viz., glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, lactate dehydrogenase, alkaline phosphatase, sorbitol and glutamate dehydrogenase) by CCl 4-induction were significantly lowered due to pretreatment with the extract. The extract also decreased the elevated serum bilirubin and urea content due to CCl 4 administration. Increased activities of hepatic 5′-nucleotidase, acid phosphatase, acid ribonuclease and decreased levels of succinic dehydrogenase, glucose-6-phosphatase and cytochrome P-450 produced by CCl 4 were reversed by the extract in a dose-responsive way. Results of this study revealed that carrot could afford a significant protective action in the alleviation of CCl 4-induced hepatocellular injury.

Elevated lipid peroxidation, decreased glutathione levels and changes in glutathione-related enzymes in rats treated with human placental extract.

The in vivo effects of human placental extract (1-4 ml/kg) on hepatic lipid peroxidation, blood and liver glutathione (GSH) levels and several enzymes associated with the antioxidant defence mechanism; i.e., catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase, together with some blood biochemical responses were investigated in rats. At an optimal dose level (4 ml/kg), a single acute intraperitoneal administration of the extract caused a significant enhancement (49.9%; p < 0.001) of lipid peroxidation with a decline in GSH level both in blood (45.1%; p < 0.001) and liver (61.0%; p < 0.001) in comparison to control animals. Activities of catalase, glutathione peroxidase and glutathione reductase were inhibited in a dose-responsive way by the treatment with the extract which also increased the activity of glutathione S-transferase in a dose-dependent manner. The extract was found to be hepatotoxic in terms of elevation of serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, serum lactate dehydrogenase and blood methemoglobin concentration. Results of this study suggest the adverse consequences of the administration of the extract due to its substantial ability to alter normal cellular processes.

Clearance of Aerosolized 99mTc-Diethyle nettaminepentacetate Before and After Smoke Inhalation

The pulmonary clearance of aerosolized 99mTc-diethylenetriaminepentacetate (DTPA) was studied in mongrel dogs immediately after exposure to wood smoke to see if a sensitive, objective way of assessing the degree of pulmonary injury might be found. Animals were studied in four groups as follows: control, following five minutes, two minutes, and 15 seconds of smoke exposure. Chest roentgenograms and 133Xe scans were taken before and after smoke exposure. The DTPA clearance was more sensitive in detecting injury than either of these imaging techniques. The DTPA clearance rates increased in a dose responsive way following smoke inhalation: 2.4 percent and 12.1 percent excreted per minute for control animals and those exposed to five minutes of smoke, respectively. Seven patients in a clinical trial of DTPA following smoke exposure are described; their DTPA clearance rates were all normal, although five were active cigarette smokers. Despite encouraging results in animal experiments, DTPA clearance studies may be of little practical value in the clinical setting of acute inhalation injury.

Studies on the mechanism of action of 2-β- d-ribofuranosylthiazole-4-carboxamide (NSC 286193)-II : Relationship between dose level and biochemical effects in P388 leukemia in vivo

Administration of the novel thiazole C-nucleoside, 2-β- d-ribofuranosylthiazole-4-carboxamide (NSC 286193), to BDF 1 mice bearing subcutaneous implants of P388 leukemia provoked a sharp depression in the concentration of intratumoral guanine nucleotides and a correspondingly large expansion of the IMP pools. Measurements of IMP dehydrogenase in the tumors of treated mice revealed that this enzyme was inhibited in a dose-responsive way, with ∼50% inhibition engendered by the administration of the drug at a dose of 25 mg/kg and > 90% inhibition by all doses > 100 mg/kg. The inhibition of enzyme activity, seen after a dose of 250 mg/kg, reached a maximum 120 min after treatment and had subsided substantially 8 hr after dosing; by 24 hr, enzyme activity was fully restored. These results, coupled with the observation that the antitumor activity of the drug could be prevented in large part by the simultaneous administration of guanosine, support the conclusion that 2-β- d-ribofuranosylthiazole-4-carboxamide, after anabolism, exerts its antineoplastic effects via a state of guanine nucleotide depletion. In extracts of the tumors of mice given parenteral injections of the thiazole nucleoside, a potent dialyzable inhibitor of IMP dehydrogenase was demonstrable; its concentration fluctuated in parallel with enzyme inhibition. Although the chemical identity of the proximate inhibitory species has yet to be established, it is concluded on kinetic grounds that it is neither the native nucleoside nor its 5′-monophosphate.