The interaction of HAb18G/CD147 with integrin α6β1 and its implications for the invasion potential of human hepatoma cells

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Tang Juan

2009-09-01

Full Text Available Abstract Background HAb18G/CD147 plays pivotal roles in invasion by hepatoma cells, but the underlying mechanism remains unclear. Our previous study demonstrated that overexpression of HAb18G/CD147 promotes invasion by interacting with integrin α3β1. However, it has never been investigated whether α3β1 is solely responsible for this process or if other integrin family members also interact with HAb18G/CD147 in human hepatoma cells. Methods Human SMMC-7721 and FHCC98 cells were cultured and transfected with siRNA fragments against HAb18G/CD147. The expression levels of HAb18G/CD147 and integrin α6β1 were determined by immunofluorescent double-staining and confocal imaging analysis. Co-immunoprecipitation and Western blot analyses were performed to examine the native conformations of HAb18G/CD147 and integrin α6β1. Invasion potential was evaluated with an invasion assay and gelatin zymography. Results We found that integrin α6β1 co-localizes and interacts with HAb18G/CD147 in human hepatoma cells. The enhancing effects of HAb18G/CD147 on invasion capacity and secretion of matrix metalloproteinases (MMPs were partially blocked by integrin α6β1 antibodies (P 2+ mobilization, significantly reduced cell invasion potential and secretion of MMPs in human hepatoma cells (P Conclusion These results suggest that α6β1 interacts with HAb18G/CD147 to mediate tumor invasion and metastatic processes through the PI3K pathway.

Management of multidrug-resistant tuberculosis in human immunodeficiency virus patients

Science.gov (United States)

Jamil, K. F.

2018-03-01

Tuberculosis (TB) is a chronic infectious disease mainly caused by Mycobacterium tuberculosis(MTB). 10.4 million new TB cases will appear in 2015 worldwide. There were an estimated 1.4 million TB deaths in 2015, and an additional 0.4 million deaths resulting from TB disease among people living with human immunodeficiency virus (HIV). Multidrug- resistant and extensively drug-resistant tuberculosis (MDR and XDR-TB) are major public health concerns worldwide. 480.000 new cases of MDR-TB will appear in 2015 and an additional 100,000 people with rifampicin-resistant TB (RR-TB) who were also newly eligible for MDR-TB treatment. Their association with HIV infection has contributed to the slowing down of TB incidence decline over the last two decades, therefore representing one important barrier to reach TB elimination. Patients infected with MDR-TB require more expensive treatment regimens than drug-susceptible TB, with poor treatment.Patients with multidrug- resistant tuberculosis do not receive rifampin; drug interactions risk is markedly reduced. However, overlapping toxicities may limit options for co-treatment of HIV and multidrug- resistant tuberculosis.

Basil extract inhibits the sulfotransferase mediated formation of DNA adducts of the procarcinogen 1'-hydroxyestragole by rat and human liver S9 homogenates and in HepG2 human hepatoma cells

NARCIS (Netherlands)

Jeurissen, S.M.F.; Punt, A.; Delatour, T.; Rietjens, I.M.C.M.

2008-01-01

The effects of a basil extract on the sulfation and concomitant DNA adduct formation of the proximate carcinogen 1¿-hydroxyestragole were studied using rat and human liver S9 homogenates and the human hepatoma cell line HepG2. Basil was chosen since it contains the procarcinogen estragole that can

GEP100/Arf6 is required for epidermal growth factor-induced ERK/Rac1 signaling and cell migration in human hepatoma HepG2 cells.

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ZhenZhen Hu

Full Text Available BACKGROUND: Epidermal growth factor (EGF signaling is implicated in the invasion and metastasis of hepatoma cells. However, the signaling pathways for EGF-induced motility of hepatoma cells remain undefined. METHODOLOGY/PRINCIPAL FINDINGS: We found that EGF dose-dependently stimulated the migration of human hepatoma cells HepG2, with the maximal effect at 10 ng/mL. Additionally, EGF increased Arf6 activity, and ectopic expression of Arf6 T27N, a dominant negative Arf6 mutant, largely abolish EGF-induced cell migration. Blocking GEP100 with GEP100 siRNA or GEP100-△PH, a pleckstrin homology (PH domain deletion mutant of GEP100, blocked EGF-induced Arf6 activity and cell migration. EGF also increased ERK and Rac1 activity. Ectopic expression GEP100 siRNA, GEP100-△PH, or Arf6-T27N suppressed EGF-induced ERK and Rac1 activity. Furthermore, blocking ERK signaling with its inhibitor U0126 remarkably inhibited both EGF-induced Rac1 activation as well as cell migration, and ectopic expression of inactive mutant form of Rac1 (Rac1-T17N also largely abolished EGF-induced cell migration. CONCLUSIONS/SIGNIFICANCE: Taken together, this study highlights the function of the PH domain of GEP100 and its regulated Arf6/ERK/Rac1 signaling cascade in EGF-induced hepatoma cell migration. These findings could provide a rationale for designing new therapy based on inhibition of hepatoma metastasis.

Basil extract inhibits the sulfotransferase mediated formation of DNA adducts of the procarcinogen 1′-hydroxyestragole by rat and human liver S9 homogenates and in HepG2 human hepatoma cells

NARCIS (Netherlands)

Jeurissen, S.M.F.; Punt, A.; Delatour, T.; Rietjens, I.M.C.M.

2008-01-01

The effects of a basil extract on the sulfation and concomitant DNA adduct formation of the proximate carcinogen 1′-hydroxyestragole were studied using rat and human liver S9 homogenates and the human hepatoma cell line HepG2. Basil was chosen since it contains the procarcinogen estragole that can

Differential Cytotoxicity of Acetaminophen in Mouse Macrophage J774.2 and Human Hepatoma HepG2 Cells: Protection by Diallyl Sulfide.

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Haider Raza

Full Text Available Non-steroidal anti-inflammatory drugs (NSAIDs, including acetaminophen (APAP, have been reported to induce cytotoxicity in cancer and non-cancerous cells. Overdose of acetaminophen (APAP causes liver injury in humans and animals. Hepatic glutathione (GSH depletion followed by oxidative stress and mitochondrial dysfunction are believed to be the main causes of APAP toxicity. The precise molecular mechanism of APAP toxicity in different cellular systems is, however, not clearly understood. Our previous studies on mouse macrophage J774.2 cells treated with APAP strongly suggest induction of apoptosis associated with mitochondrial dysfunction and oxidative stress. In the present study, using human hepatoma HepG2 cells, we have further demonstrated that macrophages are a more sensitive target for APAP-induced toxicity than HepG2 cells. Using similar dose- and time-point studies, a marked increase in apoptosis and DNA fragmentation were seen in macrophages compared to HepG2 cells. Differential effects of APAP on mitochondrial respiratory functions and oxidative stress were observed in the two cell lines which are presumably dependent on the varying degree of drug metabolism by the different cytochrome P450s and detoxification by glutathione S-transferase enzyme systems. Our results demonstrate a marked increase in the activity and expression of glutathione transferase (GST and multidrug resistance (MDR1 proteins in APAP-treated HepG2 cells compared to macrophages. This may explain the apparent resistance of HepG2 cells to APAP toxicity. However, treatment of these cells with diallyl sulfide (DAS, 200 μM, a known chemopreventive agent from garlic extract, 24 h prior to APAP (10 μmol/ml for 18h exhibited comparable cytoprotective effects in the two cell lines. These results may help in better understanding the mechanism of cytotoxicity caused by APAP and cytoprotection by chemopreventive agents in cancer and non-cancerous cellular systems.

Sphere-forming cell subpopulations with cancer stem cell properties in human hepatoma cell lines

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Chen Lei

2011-06-01

Full Text Available Abstract Background Cancer stem cells (CSCs are regarded as the cause of tumor formation and recurrence. The isolation and identification of CSCs could help to develop novel therapeutic strategies specifically targeting CSCs. Methods Human hepatoma cell lines were plated in stem cell conditioned culture system allowed for sphere forming. To evaluate the stemness characteristics of spheres, the self-renewal, proliferation, chemoresistance, tumorigenicity of the PLC/PRF/5 sphere-forming cells, and the expression levels of stem cell related proteins in the PLC/PRF/5 sphere-forming cells were assessed, comparing with the parental cells. The stem cell RT-PCR array was performed to further explore the biological properties of liver CSCs. Results The PLC/PRF/5, MHCC97H and HepG2 cells could form clonal nonadherent 3-D spheres and be serially passaged. The PLC/PRF/5 sphere-forming cells possessed a key criteria that define CSCs: persistent self-renewal, extensive proliferation, drug resistance, overexpression of liver CSCs related proteins (Oct3/4, OV6, EpCAM, CD133 and CD44. Even 500 sphere-forming cells were able to form tumors in NOD/SCID mice, and the tumor initiating capability was not decreased when spheres were passaged. Besides, downstream proteins DTX1 and Ep300 of the CSL (CBF1 in humans, Suppressor of hairless in Drosophila and LAG1 in C. elegans -independent Notch signaling pathway were highly expressed in the spheres, and a gamma-secretase inhibitor MRK003 could significantly inhibit the sphere formation ability. Conclusions Nonadherent tumor spheres from hepatoma cell lines cultured in stem cell conditioned medium possess liver CSC properties, and the CSL-independent Notch signaling pathway may play a role in liver CSCs.

microRNA-mediated resistance to hypoglycemia in the HepG2 human hepatoma cell line

International Nuclear Information System (INIS)

Ueki, Satomi; Murakami, Yuko; Yamada, Shoji; Kimura, Masaki; Saito, Yoshimasa; Saito, Hidetsugu

2016-01-01

It is generally accepted that the energy resources of cancer cells rely on anaerobic metabolism or the glycolytic system, even if they have sufficient oxygen. This is known as the Warburg effect. The cells skillfully survive under hypoglycemic conditions when their circumstances change, which probably at least partly involves microRNA (miRNA)-mediated regulation. To determine how cancer cells exploit miRNA-mediated epigenetic mechanisms to survive in hypoglycemic conditions, we used DNA microarray analysis to comprehensively and simultaneously compare the expression of miRNAs and mRNAs in the HepG2 human hepatoma cell line and in cultured normal human hepatocytes. The hypoglycemic condition decreased the expression of miRNA-17-5p and -20a-5p in hepatoma cells and consequently upregulated the expression of their target gene p21. These regulations were also confirmed by using antisense inhibitors of these miRNAs. In addition to this change, the hypoglycemic condition led to upregulated expression of heat shock proteins and increased resistance to caspase-3-induced apoptosis. However, we could not identify miRNA-mediated regulations, despite using comprehensive detection. Several interesting genes were also found to be upregulated in the hypoglycemic condition by the microarray analysis, probably because of responding to this cellular stress. These results suggest that cancer cells skillfully survive in hypoglycemic conditions, which frequently occur in malignancies, and that some of the gene regulation of this process is manipulated by miRNAs. The online version of this article (doi:10.1186/s12885-016-2762-7) contains supplementary material, which is available to authorized users

Studies on Anti-Hepatoma Effect of Gan-Ai-Xiao Decoction

African Journals Online (AJOL)

Nowadays, the people's lifestyles such as obesity [1], smoking [2] and alcohol drinking [3] enhance the incidence of hepatoma. Hepatoma is the second leading cause of cancer mortality worldwide [4] and a number of therapies have been used to decrease the mortality of patients with hepatoma, such as surgical treatment ...

CYP1A1 and CYP1A2 expression: Comparing 'humanized' mouse lines and wild-type mice; comparing human and mouse hepatoma-derived cell lines

International Nuclear Information System (INIS)

Uno, Shigeyuki; Endo, Kaori; Ishida, Yuji; Tateno, Chise; Makishima, Makoto; Yoshizato, Katsutoshi; Nebert, Daniel W.

2009-01-01

Human and rodent cytochrome P450 (CYP) enzymes sometimes exhibit striking species-specific differences in substrate preference and rate of metabolism. Human risk assessment of CYP substrates might therefore best be evaluated in the intact mouse by replacing mouse Cyp genes with human CYP orthologs; however, how 'human-like' can human gene expression be expected in mouse tissues? Previously a bacterial-artificial-chromosome-transgenic mouse, carrying the human CYP1A1 C YP1A2 locus and lacking the mouse Cyp1a1 and Cyp1a2 orthologs, was shown to express robustly human dioxin-inducible CYP1A1 and basal versus inducible CYP1A2 (mRNAs, proteins, enzyme activities) in each of nine mouse tissues examined. Chimeric mice carrying humanized liver have also been generated, by transplanting human hepatocytes into a urokinase-type plasminogen activator(+/+) s evere-combined-immunodeficiency (uPA/SCID) line with most of its mouse hepatocytes ablated. Herein we compare basal and dioxin-induced CYP1A mRNA copy numbers, protein levels, and four enzymes (benzo[a]pyrene hydroxylase, ethoxyresorufin O-deethylase, acetanilide 4-hydroxylase, methoxyresorufin O-demethylase) in liver of these two humanized mouse lines versus wild-type mice; we also compare these same parameters in mouse Hepa-1c1c7 and human HepG2 hepatoma-derived established cell lines. Most strikingly, mouse liver CYP1A1-specific enzyme activities are between 38- and 170-fold higher than human CYP1A1-specific enzyme activities (per unit of mRNA), whereas mouse versus human CYP1A2 enzyme activities (per unit of mRNA) are within 2.5-fold of one another. Moreover, both the mouse and human hepatoma cell lines exhibit striking differences in CYP1A mRNA levels and enzyme activities. These findings are relevant to risk assessment involving human CYP1A1 and CYP1A2 substrates, when administered to mice as environmental toxicants or drugs.

Structural basis of small-molecule inhibition of human multidrug transporter ABCG2

DEFF Research Database (Denmark)

Jackson, Scott M; Manolaridis, Ioannis; Kowal, Julia

2018-01-01

requires high-resolution structural insight. Here, we present cryo-EM structures of human ABCG2 bound to synthetic derivatives of the fumitremorgin C-related inhibitor Ko143 or the multidrug resistance modulator tariquidar. Both compounds are bound to the central, inward-facing cavity of ABCG2, blocking...

The human multidrug resistance-associated protein MRP is a plasma membrane drug-efflux pump

NARCIS (Netherlands)

Zaman, G. J.; Flens, M. J.; van Leusden, M. R.; de Haas, M.; Mülder, H. S.; Lankelma, J.; Pinedo, H. M.; Scheper, R. J.; Baas, F.; Broxterman, H. J.

1994-01-01

The multidrug-resistance associated protein MRP is a 180- to 195-kDa membrane protein associated with resistance of human tumor cells to cytotoxic drugs. We have investigated how MRP confers drug resistance in SW-1573 human lung carcinoma cells by generating a subline stably transfected with an

Effects of JS-K, a novel anti-cancer nitric oxide prodrug, on gene expression in human hepatoma Hep3B cells.

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Dong, Ray; Wang, Xueqian; Wang, Huan; Liu, Zhengyun; Liu, Jie; Saavedra, Joseph E

2017-04-01

JS-K is a novel anticancer nitric oxide (NO) prodrug effective against a variety of cancer cells, including the inhibition of AM-1 hepatoma cell growth in rats. To further evaluate anticancer effects of JS-K, human hepatoma Hep3B cells were treated with JS-K and the compound control JS-43-126 at various concentrations (0-100μM) for 24h, and cytotoxicity was determined by the MTS assay. The compound control JS-43-126 was not cytotoxic to Hep3B cells at concentrations up to 100μM, while the LC 50 for JS-K was about 10μM. To examine the molecular mechanisms of antitumor effects of JS-K, Hep3B cells were treated with 1-10μM of JS-K for 24h, and then subjected to gene expression analysis via real time RT-PCR and protein immunostain via confocal images. JS-K is a GST-α targeting NO prodrug, and decreased immunostaining for GST-α was associated with JS-K treatment. JS-K activated apoptosis pathways in Hep3B cells, including induction of caspase-3, caspase-9, Bax, TNF-α, and IL-1β, and immunostaining for caspase-3 was intensified. The expressions of thrombospondin-1 (TSP-1) and the tissue inhibitors of metalloproteinase-1 (TIMP-1) were increased by JS-K at both transcript and protein levels. JS-K treatment also increased the expression of differentiation-related genes CD14 and CD11b, and depressed the expression of c-myc in Hep3B cells. Thus, multiple molecular events appear to be associated with anticancer effects of JS-K in human hepatoma Hep3B cells, including activation of genes related to apoptosis and induction of genes involved in antiangiogenesis and tumor cell migration. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Regulation of low density lipoprotein receptor function in a human hepatoma cell line

International Nuclear Information System (INIS)

Leichtner, A.M.; Krieger, M.; Schwartz, A.L.

1984-01-01

Low density lipoprotein (LDL) processing was investigated in a human hepatoma-derived cell line, Hep G2. Hep G2 cells bound, internalized and degraded LDL via a saturable, high affinity pathway similar to that present in other mammalian cells. Although 80% of the uptake and degradation of 125 I-LDL was inhibited by 40-fold excess native LDL, the same concentration of methylated LDL, which cannot bind to LDL receptors, had virtually no effect on processing. When added at low concentrations, the lysosomotropic agent, chloroquine, inhibited degradation without affecting the rate of lipoprotein internalization. Receptor activity was decreased 60% by preincubation of the cells in medium containing a source of cholesterol (LDL or unesterified cholesterol) and increased 1.7-fold by preincubation with compactin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase. The Hep G2 cell line may prove a useful system both for the further study of hepatic lipoprotein metabolism and for the evaluation of new antihypercholesterolemic agents

Analysis of the cytotoxicity of carbon-based nanoparticles, diamond and graphite, in human glioblastoma and hepatoma cell lines

DEFF Research Database (Denmark)

Zakrzewska, Karolina Ewa; Samluk, Anna; Wierzbicki, Mateusz

2015-01-01

carbon based nanoparticles, diamond and graphite, on glioblastoma and hepatoma cells were compared. First, we confirmed previous results that diamond nanoparticles are practically nontoxic. Second, graphite nanoparticles exhibited a negative impact on glioblastoma, but not on hepatoma cells. The studied...... carbon nanoparticles could be a potentially useful tool for therapeutics delivery to the brain tissue with minimal side effects on the hepatocytes. Furthermore, we showed the influence of the nanoparticles on the stable, fluorescently labeled tumor cell lines and concluded that the labeled cells...

Synergistic inhibitory effect of hyperbaric oxygen combined with sorafenib on hepatoma cells.

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Hai-Shan Peng

Full Text Available OBJECTIVES: Hypoxia is a common phenomenon in solid tumors, associated with chemotherapy and radiotherapy resistance, recurrence and metastasis. Hyperbaric oxygen (HBO therapy can increase tissue oxygen pressure and content to prevent the resistance, recurrence and metastasis of cancer. Presently, Sorafenib is a first-line drug, targeted for hepatocellular carcinoma (HCC but effective in only a small portion of patients and can induce hypoxia. The purpose of this study is to investigate the effect of HBO in combination with sorafenib on hepatoma cells. METHODS: Hepatoma cell lines (BEL-7402 and SK-Hep1 were treated with HBO at 2 atmosphere absolute pressure for 80 min per day or combined with sorafenib or cisplatin. At different time points, cells were tested for cell growth, colony formation, apoptosis, cell cycle and migration. Finally, miRNA from the hepatoma cells was detected by microRNA array and validated by qRT-PCR. RESULTS: Although HBO, sorafenib or cisplatin alone could inhibit growth of hepatoma cells, HBO combined with sorafenib or cisplatin resulted in much greater synergistic growth inhibition (cell proliferation and colony formation in hepatoma cells. Similarly, the synergistic effect of HBO and sorafenib on induction of apoptosis was also observed in hepatoma cells. HBO induced G1 arrest in SK-Hep1 not in BEL-7402 cells, but enhanced cell cycle arrest induced by sorafenib in BEL-7402 treated cells. However, HBO had no obvious effect on the migration of hepatoma cells, and microRNA array analysis showed that hepatoma cells with HBO treatment had significantly different microRNA expression profiles from those with blank control. CONCLUSIONS: We show for the first time that HBO combined with sorafenib results in synergistic growth inhibition and apoptosis in hepatoma cells, suggesting a potential application of HBO combined with sorafenib in HCC patients. Additionally, we also show that HBO significantly altered microRNA expression

Biodistribution and SPECT imaging of 99Tcm labeling NGR peptide in nude mice bearing human HePG2 hepatoma

International Nuclear Information System (INIS)

Ma Wenhui; Wang Jing; Yang Weidong; Li Guiyu; Ma Xiaowei; Wang Zhe

2012-01-01

A peptide containing the Asn-Gly-Arg (NGR) sequence was radiolabeled by 99 Tc m and its radiochemical characteristics, biodistribution and SPECT imaging in nude mice bearing human HePG2 hepatoma were evaluated. 99 Tc m -NGR was prepared directly with a labeling yield higher than 90%, and the radiochemical purity (RCP) higher than 95%. Nude mice bearing human HePG2 hepatoma were randomly divided into 6 groups with 3 mice in each group. The control group mice were blocked by injecting 100 μg unlabeled NGR 0.5 h before 99 Tc m -NGR injection. The mice were sacrificed at 1, 2, 4, 8, 12 h after caudal intravenous injection of 7.4 MBq 99 Tc m -NGR. The uptakes of kidney and liver were very high. Tumor uptake was (2.52±0.62)% ID/g at 1 h, with the highest uptake of (7.26±2.71) %ID/g. At 12 h, the uptake was still (3.93±1.93) %ID/g. In comparison, the uptake of the blocked control group was (1.29±0.85) %ID/g. The SPECT static images of 3 mice and the tumor/muscle (T/NT) value were obtained. The highest T/NT value was 3.25 at 4 h. The xenografted tumor became visible at 1 h and the clearest image of the tumor was observed at 12 h. Results from this work shows that 99 Tc m -NGR can be efficiently prepared, can favorably target tumor angiogenesis, and should be a potential probe in tumor therapy. (authors)

I-123-insulin: A new marker for hepatoma

International Nuclear Information System (INIS)

Sodoyez, J.C.; Goffaux, F.S.; Fallais, C.; Bourgeois, P.

1984-01-01

Previous studies have demonstrated that carrier-free I-123-Tyr Al4 insulin was taken up by the liver (by a saturable mechanism) and by the kidneys (by a non saturable mechanism). Autoradiographs of rat liver after injection of I-125-insulin showed that binding specifically occurred at the plasma membrane of the hepatocytes. I-123-Insulin binding to the hepatocyte plasma membrane appeared mediated by specific receptors. Indeed it was blocked by antibodies to the insulin receptors and by an excess of native insulin. Futhermore insulin derivatives with low biological potency (proinsulin and desoctapeptide insulin) did not inhibit I-123-insulin binding to the hepatocytes. I-123-Insulin (1.3 mCi) was I.V. injected into a patient in whom the right liver lobe was normal (normal uptake of Tc-99m-colloid sulfur) but the left liver lobe was occupied by a voluminous hepatoma (no uptake of Tc-99m-colloid sulfur). Liver blood supply was also studied by Tc-99m-pyrophosphate-labeled red cells. Computer analysis of the data revealed that compared to the normal liver lobe, binding of I-123-insulin to the hepatoma was more precocious (vascularization through the hepatic artery and not the portal vein), more intense and more prolonged (half-lives were 6 min in the normal liver and 14 min in the hepatoma). These results are consistent with characteristics of hepatoma cells in culture in which high insulin binding capacity contrasts with a markedly decreased insulin degrading activity. It is concluded that I-123-insulin may be used as a specific marker of hepatoma in man

Arecoline inhibits the 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced cytochrome P450 1A1 activation in human hepatoma cells

International Nuclear Information System (INIS)

Chang, Eddy Essen; Miao Zhifeng; Lee, W.-J.; Chao, H.-R.; Li, Lih-Ann; Wang, Y.-F.; Ko, Y.-C.; Tsai, F.-Y.; Yeh, S.C.; Tsou, T.-C.

2007-01-01

In the present study, we investigated the effect of arecoline, a major areca nut alkaloid, on the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced activation of cytochrome P4501A1 (CYP1A1) in a human hepatoma cell line Huh-7. We treated Huh-7 cells with 10 nM TCDD in the presence of different concentrations of arecoline (50-300 μM). Our results indicated that arecoline attenuated the TCDD-induced CYP1A1 enzyme activation with an inhibitory effect on cell proliferation. By using real-time RT-PCR, we demonstrated that arecoline inhibited the TCDD-induced activations of CYP1A1 and AhR repressor (AhRR) mRNA expression in a similar pattern. Our results revealed that arecoline inhibited AhR mRNA expression with no direct effect on CYP1A1 enzyme activity. Therefore, in our present study, the observed inhibitory effect of arecoline on CYP1A1 activation was not due to the up-regulation of AhRR or direct inhibitory effect on CYP1A1. Taken together, here we have demonstrated that arecoline attenuates the TCDD-induced CYP1A1 activation mainly via down-regulation of AhR expression in human hepatoma cells, suggesting the possible involvement of arecoline in the AhR-mediated metabolism of environmental toxicants in liver

Mechanisms involved in growth inhibition induced by clofibrate in hepatoma cells

International Nuclear Information System (INIS)

Muzio, Giuliana; Maggiora, Marina; Trombetta, Antonella; Martinasso, Germana; Reffo, Patrizia; Colombatto, Sebastiano; Canuto, Rosa Angela

2003-01-01

Low concentrations of some peroxisome proliferators have been found to decrease apoptosis in rat liver cells, whereas higher but pharmacological concentrations have been found to inhibit cell proliferation or to induce apoptosis in human and rat hepatoma cells. The highly deviated JM2 rat hepatoma cell line was used to examine the mechanisms underlying the inhibitory effect on cell proliferation. Clofibrate chiefly inhibited cell proliferation in these cells. Parallel to the decrease in cell proliferation there was an increase of peroxisome proliferator activated receptor (PPAR) gamma and of protein phosphatase 2A, whose importance was confirmed, respectively, by using antisense oliginucleotides (AS-ODN) or okadaic acid. The increase of protein phosphatase 2A induced by PPARgamma caused a decrease of MAPK, an intracellular signaling transduction pathway, as shown by evaluation of Erk1,2 and c-myc. In light of these results, clofibrate, like conventional synthetic ligands of PPARgamma, may be regarded as a possible prototype anti-tumour drug

Skeletal metastases from hepatoma: frequency, distribution, and radiographic features

International Nuclear Information System (INIS)

Kuhlman, J.E.; Fishman, E.K.; Leichner, P.K.; Magid, D.; Order, S.E.; Siegelman, S.S.

1986-01-01

Over the past 6 years, the authors evaluated 300 patients with hepatoma as part of phase 1 and 2 treatment protocol trials. Analysis of the available clinical data and radiographic studies revealed 22 patients (7.3%) with skeletal metastases demonstrated by radiography, computed tomography (CT), and/or nuclear scintigraphy. The plain film appearance of skeletal metastases from hepatoma was osteolytic in all cases. CT scanning best demonstrated the expansile, destructive nature of these metastases, which were often associated with large, bulky soft-tissue masses. Skeletal metastases from hepatomas demonstrated increased radiotracer uptake on standard bone scans and were gallium avid, similar to the hepatoma itself. In addition, they could be targeted therapeutically with I-131 antiferritin immunoglobulin. The most frequent sites of skeletal metastases were the ribs, spine, femur, pelvis, and humerus. An initial symptom in ten patients was skeletal pain corresponding to the osseous metastases. In five patients, pathologic fractures of the proximal femur or humerus developed and required total hip replacement or open-reduction internal fixation. Patients with long-standing cirrhosis or known hepatocellular carcinoma who also have skeletal symptoms should be evaluated for possible osseous metastases

Effect of interleukin-17A on stemness of hepatoma cell lines

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LI Kexin

2017-06-01

Full Text Available ObjectiveTo investigate the effect of interleukin-17A (IL-17A on stemness of human hepatoma cell lines Hep 3B, MHCC97H, and MHCC97L and the association between IL-17A and the progression of liver cancer. MethodsHuman hepatoma cell lines Hep 3B, MHCC97H, and MHCC97L were selected, and in vitro 3D sphere formation assay was used to analyze the effect of IL-17A on sphere formation ability. The control group with common culture solution and the experimental group with 50 ng/ml IL-17A were established. Real-time cellular analysis was used to determine the effect of IL-17A on the proliferation and migration of hepatoma cells with enhanced sphere formation ability; quantitative real-time PCR was used to measure the changes in the mRNA expression of IL-17A receptors IL-17RA and IL-17RC and stemness-related genes SOX2, NANOG, OCT4, and BMI1 in hepatoma cells with enhanced sphere formation ability; Western blot was used to measure the expression of epithelial-mesenchymal transition-related proteins E-cadherin, N-cadherin, and vimentin. The t-test was used for comparison of continuous doota betwwen groups. ResultsWith the presence of 50 ng/ml IL-17A and 500 inoculated cells, Hep 3B cells had a significant increase in the number of spheres formed (113.0±10.3 vs 180.0±7.2, t=5.533, P＜0.001, while MHCC97H and MHCC97L cells showed no significant changes (t=1.087 and 0.279, P=0.325 and 0785. The analysis showed that IL-17A promoted the proliferation and migration of Hep 3B cells with an increased number of spheres formed. After the addition of 50 ng/ml IL-17A, there was an increase in the mRNA expression of IL-17A receptors IL-17RA and IL-17RC over the time of treatment; Hep 3B cells showed significant increases in the mRNA expression of stemness-related genes SOX2 (t=4.749, P=0.042, NANOG (t=19.600, P=0.003, OCT4 (t=37.310, P＜0.001, and BMI1 (t=16.810, P=0.004. Western blot showed no significant change in the expression of the epithelium

Chemopreventive Activities of Sulforaphane and Its Metabolites in Human Hepatoma HepG2 Cells

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Peng Liu

2018-05-01

Full Text Available Sulforaphane (SFN exhibits chemopreventive effects through various mechanisms. However, few studies have focused on the bioactivities of its metabolites. Here, three metabolites derived from SFN were studied, known as sulforaphane glutathione, sulforaphane cysteine and sulforaphane-N-acetylcysteine. Their effects on cell viability, DNA damage, tumorigenicity, cell migration and adhesion were measured in human hepatoma HepG2 cells, and their anti-angiogenetic effects were determined in a 3D co-culture model of human umbilical vein endothelial cells (HUVECs and pericytes. Results indicated that these metabolites at high doses decreased cancer cell viability, induced DNA damage and inhibited motility, and impaired endothelial cell migration and tube formation. Additionally, pre-treatment with low doses of SFN metabolites protected against H2O2 challenge. The activation of the nuclear factor E2-related factor 2 (Nrf2-antioxidant response element (ARE pathway and the induction of intracellular glutathione (GSH played an important role in the cytoprotective effects of SFN metabolites. In conclusion, SFN metabolites exhibited similar cytotoxic and cytoprotective effects to SFN, which proves the necessity to study the mechanisms of action of not only SFN but also of its metabolites. Based on the different tissue distribution profiles of these metabolites, the most relevant chemical forms can be selected for targeted chemoprevention.

Species-specific differences in peroxisome proliferation, catalase, and SOD2 upregulation as well as toxicity in human, mouse, and rat hepatoma cells induced by the explosive and environmental pollutant 2,4,6-trinitrotoluene.

Science.gov (United States)

Naumenko, Ekaterina Anatolevna; Ahlemeyer, Barbara; Baumgart-Vogt, Eveline

2017-03-01

2,4,6-Trinitrotoluene (TNT) has been widely used as an explosive substance and its toxicity is still of interest as it persisted in polluted areas. TNT is metabolized in hepatocytes which are prone to its toxicity. Since analysis of the human liver or hepatocytes is restricted due to ethical reasons, we investigated the effects of TNT on cell viability, reactive oxygen species (ROS) production, peroxisome proliferation, and antioxidative enzymes in human (HepG2), mouse (Hepa 1-6), and rat (H4IIEC3) hepatoma cell lines. Under control conditions, hepatoma cells of all three species were highly comparable exhibiting identical proliferation rates and distribution of their cell cycle phases. However, we found strong differences in TNT toxicity with the lowest IC 50 values (highest cell death rate) for rat cells, whereas human and mouse cells were three to sevenfold less sensitive. Moreover, a strong decrease in cellular dehydrogenase activity (MTT assay) and increased ROS levels were noted. TNT caused peroxisome proliferation with rat hepatoma cells being most responsive followed by those from mouse and human. Under control conditions, rat cells contained fivefold higher peroxisomal catalase and mitochondrial SOD2 activities and a twofold higher capacity to reduce MTT than human and mouse cells. TNT treatment caused an increase in catalase and SOD2 mRNA and protein levels in human and mouse, but not in rat cells. Similarly, human and mouse cells upregulated SOD2 activity, whereas rat cells failed therein. We conclude that TNT induced oxidative stress, peroxisome proliferation and mitochondrial damage which are highest in rat cells rendering them most susceptible toward TNT. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 989-1006, 2017. © 2016 Wiley Periodicals, Inc.

Tyramine-O-sulfate is produced and secreted by human hepatoma cells, line HepG2

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Liu, M.C.; Yu, S.; Suiko, M.

1987-01-01

Human hepatoma cells, line HepG2, were metabolically labeled with [ 35 S]sulfate. The spent medium separated following 24 hr labeling was subjected to ultrafiltration using an Amicon Centricon unit. The filtrate obtained was analyzed by a two-dimensional separation procedure combining high-voltage electrophoresis and thin-layer chromatography. The autoradiograph taken from the cellulose thin-layer plate following the analysis revealed the presence of tyramine-O-[ 35 ]sulfate in addition to tyrosine-O-[ 35 ]sulfate. Using adenosine, 3'-phosphate, 5'-phospho[ 35 S]sulfate as the sulfate donor, it was shown that tyramine was actively sulfated to form tyramine-O-[ 35 S]sulfate as catalyzed by the sulfotransferase(s) present in dog liver homogenate. Attempts to decarboxylate tyrosine-O-sulfate to tyramine-O-sulfate using intrinsic p-tyrosine decarboxylase present in dog liver homogenate, however, were unsuccessful. Employing purified Streptococcus faecalis tyrosine decarboxylase, it was shown that L-tyrosine was actively decarboxylated to tyramine, whereas tyrosine-O-sulfate could not serve as a substrate

Pokemon Silencing Leads to Bim-Mediated Anoikis of Human Hepatoma Cell QGY7703

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Kun Liu

2012-05-01

Full Text Available Pokemon is an important proto-oncogene that plays a critical role in cellular oncogenic transformation and tumorigenesis. Anoikis, which is regulated by Bim-mediated apoptosis, is critical to cancer cell invasion and metastasis. We investigated the role of Pokemon in anoikis, and our results show that Pokemon renders liver cells resistant to anoikis via suppression of Bim transcription. We knocked-down Pokemon in human hepatoma cells QGY7703 with small interfering RNAs (siRNA. Knockdown of Pokemon alone did not significantly affect the growth and survival of QGY7703 cells but notably enhanced their sensitivity to apoptotic stress due to the presence of chemical agents or cell detachment, thereby inducing anoikis, as evidenced by flow cytometry and caspase-3 activity assays. In contrast, ectopic expression of Pokemon in HL7702 cells led to resistance to anoikis. Dual-luciferase reporter and ChIP assays illustrated that Pokemon suppressed Bim transcription via direct binding to its promoter. Our results suggest that Pokemon prevents anoikis through the suppression of Bim expression, which facilitates tumor cell invasion and metastasis. This Pokemon-Bim pathway may be an effective target for therapeutic intervention for cancer.

Pokemon silencing leads to Bim-mediated anoikis of human hepatoma cell QGY7703.

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Liu, Kun; Liu, Feng; Zhang, Nannan; Liu, Shiying; Jiang, Yuyang

2012-01-01

Pokemon is an important proto-oncogene that plays a critical role in cellular oncogenic transformation and tumorigenesis. Anoikis, which is regulated by Bim-mediated apoptosis, is critical to cancer cell invasion and metastasis. We investigated the role of Pokemon in anoikis, and our results show that Pokemon renders liver cells resistant to anoikis via suppression of Bim transcription. We knocked-down Pokemon in human hepatoma cells QGY7703 with small interfering RNAs (siRNA). Knockdown of Pokemon alone did not significantly affect the growth and survival of QGY7703 cells but notably enhanced their sensitivity to apoptotic stress due to the presence of chemical agents or cell detachment, thereby inducing anoikis, as evidenced by flow cytometry and caspase-3 activity assays. In contrast, ectopic expression of Pokemon in HL7702 cells led to resistance to anoikis. Dual-luciferase reporter and ChIP assays illustrated that Pokemon suppressed Bim transcription via direct binding to its promoter. Our results suggest that Pokemon prevents anoikis through the suppression of Bim expression, which facilitates tumor cell invasion and metastasis. This Pokemon-Bim pathway may be an effective target for therapeutic intervention for cancer.

Metabolic Flux Distribution during Defatting of Steatotic Human Hepatoma (HepG2 Cells

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Gabriel Yarmush

2016-01-01

Full Text Available Methods that rapidly decrease fat in steatotic hepatocytes may be helpful to recover severely fatty livers for transplantation. Defatting kinetics are highly dependent upon the extracellular medium composition; however, the pathways involved are poorly understood. Steatosis was induced in human hepatoma cells (HepG2 by exposure to high levels of free fatty acids, followed by defatting using plain medium containing no fatty acids, or medium supplemented with a cocktail of defatting agents previously described before. We measured the levels of 28 extracellular metabolites and intracellular triglyceride, and fed the data into a steady-state mass balance model to estimate strictly intracellular fluxes. We found that during defatting, triglyceride content decreased, while beta-oxidation, the tricarboxylic acid cycle, and the urea cycle increased. These fluxes were augmented by defatting agents, and even more so by hyperoxic conditions. In all defatting conditions, the rate of extracellular glucose uptake/release was very small compared to the internal supply from glycogenolysis, and glycolysis remained highly active. Thus, in steatotic HepG2 cells, glycolysis and fatty acid oxidation may co-exist. Together, these pathways generate reducing equivalents that are supplied to mitochondrial oxidative phosphorylation.

Effects of the peroxisome proliferator clofibric acid on superoxide dismutase expression in the human HepG2 hepatoma cell line.

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Bécuwe, P; Bianchi, A; Keller, J M; Dauça, M

1999-09-15

We examined the effects of clofibric acid, a peroxisome proliferator, on the production of superoxide radicals, on the levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and on the expression of superoxide dismutases (SODs) in the human HepG2 hepatoma cell line. To this end, HepG2 cells were treated for 1 or 5 days with 0.25, 0.50, or 0.75 mM clofibric acid. The production of superoxide radicals was only enhanced in HepG2 cells exposed for 5 days to the different clofibric acid concentrations. However, this overproduction of superoxide radicals was not accompanied by increased rates of lipid peroxidation, as the MDA and 4-HNE levels did not change significantly. Manganese (Mn) SOD activity was increased when HepG2 cells were treated for 1 day with 0.50 or 0.75 mM clofibric acid. For this duration of treatment, no change was observed in total SOD and copper/zinc (Cu/Zn) SOD activities. For a 5-day treatment, total SOD and MnSOD activities as well as the enzyme apoprotein and MnSOD mRNA levels increased whatever the clofibric acid concentration used. This transcriptional induction of the MnSOD gene was correlated with an activation of the activator protein-1 transcription factor for 1 and 5 days of treatment, but was independent of nuclear factor-kappa B and of peroxisome proliferator-activated receptor. On the other hand, the PP exerted very little effect if any on Cu,ZnSOD expression. In contrast to rodent data, PP treatment of human hepatoma cells induces MnSOD expression.

Preparation of [[sup 131]I]lipiodol as a hepatoma therapeutic agent

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Jiunnguang Lo; Aiyih Wang; Yuanyaw Wei (National Tsinghua Univ., Hsinchu (Taiwan). Inst. of Nuclear Science); Wingyiu Lui; Chinwen Chi (Taipei Veterans General Hospital, Taipei (Taiwan)); Wingkai Chan (Academia Sinica, Taipei (Taiwan). Inst. of Biomedical Sciences)

1992-12-01

An isotopic exchange method was used to label lipiodol with [sup 131]I. The labelling efficiency was > 92.5%, and the radiochemical purity of [[sup 131]I]lipiodol was above 98% as determined by ITLC. The influencing factors e.g. the heating temperature, reaction, pH and storage conditions were studied and the optimum conditions were determined. In a pilot study injecting [[sup 131]I]lipiodol for the treatment of hepatoma, about 70% of hepatoma patients had a response to the treatment with a reduction of [alpha]-fetoprotein and decrease of hepatoma sizes. The overall median survival was 9 months (range 2-17 months). (author).

Incidence and significance of pleural effusion after hepatoma surgery

International Nuclear Information System (INIS)

Song, Jae Uoo; Im, Jung Gi; Ahn, Joong Mo; Kim, Seung Cheol; Kim, Sam Soo; Kim, Seung Hoon; Yeon, Kyung Mo

1994-01-01

We performed this study to evaluate the clinical significance and temporal changes of pleural effusion developed after the resection of hepatoma. We reviewed retrospectively follow-up chest radiographs of 97 patients who had undergone operation for hepatoma and had no radiologically demonstrable postoperative complications. The duration of pleural effusion was classified into five groups and the amount of pleural effusion at one week after operation was graded into four groups. Statistical significance of the relationship between the duration, amount of pleural effusion and five factors, which are location and size of tumor, age of the patients, methods of operation, and preoperative liver function, was studied respectively. Pleural effusion was developed in 63.9% (62/97) and the mean duration was 2.5 weeks. In 92% (52/56), pleural effusion disappeared spontaneously within four weeks. Patients who had hepatoma in upper portion of the right lobe developed more frequent pleural effusion which persisted longer, and was larger in amount at one week after operation(p<0.05). There were no statistically significant differences between pleural effusion and the other four factors. Pleural effusion following hepatoma surgery should not be regarded as a sign of post-operative complication, as it invariably disappears spontaneously within four weeks. Development of pleural effusion is considered to be caused by local irritation and disturbance of lymphatic flow at the diaphragm

Liver regeneration in mice bearing a transplanted hepatoma.

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Badran, A F; Moreno, F R; Echave Llanos, J M

1984-01-01

The hepatocyte mitotic index curve in hepatectomized hepatoma-bearing mice, rises earlier, has a greater amplitude and is less synchronized than that of normal hepatectomized mice. This indicates a stimulation (more mitosis in a shorter time period) produced by the presence of the tumors. The sinusoid litoral cells mitotic index curve in hepatectomized hepatoma-bearing mice appears earlier and is much less synchronized than that of normal hepatectomized mice. Nevertheless both curves have the same amplitude for the whole sampling period and the early stimulation is quickly compensated by lower values (apparent inhibition) appearing in the resting (light) period.

Multidrug efflux pumps in Staphylococcus aureus and their clinical implications.

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Jang, Soojin

2016-01-01

Antibiotic resistance is rapidly spreading among bacteria such as Staphylococcus aureus, an opportunistic bacterial pathogen that causes a variety of diseases in humans. For the last two decades, bacterial multidrug efflux pumps have drawn attention due to their potential association with clinical multidrug resistance. Numerous researchers have demonstrated efflux-mediated resistance in vitro and in vivo and found novel multidrug transporters using advanced genomic information about bacteria. This article aims to provide a concise summary of multidrug efflux pumps and their important clinical implications, focusing on recent findings concerning S. aureus efflux pumps.

Various imaging methods in the detection of small hepatomas

International Nuclear Information System (INIS)

Nakatsuka, Haruki; Kaminou, Toshio; Takemoto, Kazumasa; Takashima, Sumio; Kobayashi, Nobuyuki; Nakamura, Kenji; Onoyama, Yasuto; Kurioka, Naruto

1985-01-01

Fifty-one patients with small hepatomas under 5 cm in diameter were studied to compare the detectability of various imaging methods. Positive finding was obtained in 50 % of the patients by scintigraphy, in 74 % by ultrasonography and in 79 % by CT during screening tests. Rate of detection in retrospective analysis, after the site of the tumor had been known, were 73 %, 93 % and 87 % respectively. Rate of detection was 92 % by celiac arteriography and 98 % by selective hepatic arteriography. In 21 patients, who had the tumor under 3 cm, the rate was 32 % for scintigraphy, 74 % for ultrasonography and 65 % for CT during screening, whereas it was 58 %, 84 % and 75 % retrospectively. By celiac arteriography, it was 85 %, and by hepatic arteriography, 95 %. Rate of detection of small hepatomas in screening tests differed remarkably from that in retrospective analysis. No single method of imaging can disclose reliably the presense of small hepatoma, therefore more than one method should be used in screening. (author)

Serum concentration of alpha-1-fetoprotein suggestive of, or pathognomonic for hepatoma

International Nuclear Information System (INIS)

Polterauer, P.; Horak, W.; Legenstein, E.; Mueller, M.

1979-01-01

A short review of alpha-1-fetoprotein (AFP), is followed by a presentation of the serum AFP concentrations obtained in healthy subjects and in patients with hepatoma, cirrhosis of the liver or metastatic liver cancer, measured by radioimmunoassay (RIA). A calculation is made from these results of the upper limit of normal (9 ng/ml), a limit which is suggestive of hepatome (215 ng/ml) and a limit which is pathognomonic for hepatoma (7500 ng/ml). It is concluded that the quantitative determination of AFP by RIA represents a sensitive method which provides valuable clinical information for the early diagnosis of hepatoma. (author)

Circumvention of multidrug resistance and reduction of cardiotoxicity of doxorubicin in vivo by coupling it with low density lipoprotein.

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Lo, Elka H K; Ooi, Vincent E L; Fung, K P

2002-12-27

Doxorubicin (Dox) was coupled into human low density lipoprotein (LDL) to form a complex LDL-Dox. In in vitro studies, the accumulation of LDL-Dox in human resistant hepatoma (R-HepG2) cells was found to be higher than that of free Dox in the cells, resulting in an increase of the cytotoxic effect on the cells. Moreover, in in vivo studies, under the same dosage of drugs (1 mg/kg), the anti-proliferative effect on the tumor cells of LDL-Dox in nude mice bearing R-HepG2 cells was higher than that of free Dox as evidenced by the larger reduction in tumor volumes and tumor weights in LDL-Dox treated group. Histological studies showed that LDL-Dox treatment did not cause any heart damage when compared with the control group. In contrast, Dox treatment caused disruption and vacuolization of myocardial filament. Plasma lactate dehydrogenase activity and plasma creatine kinase activity in nude mice bearing R-HepG2 cells were found to be elevated in the Dox-treated group but remained unchanged in LDL-Dox-treated group. The present studies indicate that when Dox is coupled with LDL, the multidrug resistance can be circumvented and the cardiotoxicity can be reduced.

Over-expression and siRNA of a novel environmental lipopolysaccharide-responding gene on the cell cycle of the human hepatoma-derived cell line HepG2

International Nuclear Information System (INIS)

Du Kejun; Chai Yubo; Hou Lichao; Chang Wenhui; Chen Suming; Luo Wenjing; Cai Tongjian; Zhang Xiaonan; Chen Nanchun; Chen Yaoming; Chen Jingyuan

2008-01-01

Lipopolysaccharide (LPS) is the toxic determinant for Gram-negative bacterium infection. The individual response to LPS was related to its gene background. It is necessary to identify new molecules and signaling transduction pathways about LPS. The present study was undertaken to evaluate the effects of a novel environmental lipopolysaccharide-responding (Elrg) gene on the regulation of proliferation and cell cycle of the hepatoma-derived cell line, HepG2. By means of RT-PCR, the new molecule of Elrg was generated from a human dental pulp cell cDNA library. Expression level of Elrg in HepG2 cells was remarkably upgraded by the irritation of LPS. Localization of Elrg in HepG2 cells was positioned mainly in cytoplasm. HepG2 cells were markedly arrested in the G1 phase by over-expressing Elrg. The percentage of HepG2 cells in G1 phase partly decreased after Elrg-siRNA. In conclusion, Elrg is probably correlative with LPS responding. Elrg is probably a new protein in cytoplasm which plays an important role in regulating cell cycle. The results will deepen our understanding about the potential effects of Elrg on the human hepatoma-derived cell line HepG2

HYPOLIPIDEMIC EFFECT OF ARGLABIN IN HEPATOMA TISSUE CULTURE

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A. V. Ratkin

2015-01-01

Full Text Available Objective. Investigation of hypolipidemic effect of sesquiterpene γ-lactone Arglabin in hepatoma tissue culture (HTC.Materials and methods. In this study we’ve evaluated the effect of sesquiterpene γ-lactone Arglabin and gemfibrozil (reference drug on the lipid content in the hepatoma tissue culture (HTC which were incubated with a fat emulsion “Lipofundin” by fluorescent method with vital dye Nile Red. The cell viability was investigated using the MTT-test and staining by Trypan blue.Results. Cultivation of cell cultures of rat’s hepatoma cell line HTC with Arglabin and gemfibrozil in concentrations from 10 to 50 μmol and from 0.25 to 0.5 mmol, respectively, had no cytotoxic effect. HTC cell viability did not change compared with the corresponding rate in the control culture. Experimental hyperlipidemia in hepatoma culture was induced by the addition in the incubation medium of fat emulsion “Lipofundin” in a final concentration of 0.05 %. The fluorescence intensity of Nile Red in the cells was increased 4-fold (p < 0.05, which indicates a significant accumulation of lipids in the cytosol of cells. In these steady-state Arglabin and gemfibrozil at concentrations 75–100 μM and 0.25–1.0 mM, respectively, reduced the content of lipid in cells. Conclusion. In the model of hyperlipidemia induced by lipofundin, sesquiterpene γ-lactone Arglabin prevents the accumulation of lipids in the HTC cell line, as evidenced by a decrease in Nile Red fluorescence. However hypolipidemic effect of Arglabin is associated with cytotoxic effects, which is typical for anticancer drugs.

Size-dependent cytotoxicity of Fe3O4 nanoparticles induced by biphasic regulation of oxidative stress in different human hepatoma cells

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Xie Y

2016-07-01

Full Text Available Yuexia Xie,1,2,* Dejun Liu,3,* Chenlei Cai,1,* Xiaojing Chen,1 Yan Zhou,1 Liangliang Wu,1 Yongwei Sun,3 Huili Dai,1,2 Xianming Kong,1,2 Peifeng Liu1,2 1Central Laboratory, 2State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, 3Department of Biliary-Pancreatic Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The application of Fe3O4 nanoparticles (NPs has made great progress in the diagnosis of disease and in the drug delivery system for cancer therapy, but the relative mecha­nisms of potential toxicity induced by Fe3O4 have not kept pace with its development in the application, which has hampered its further clinical application. In this article, we used two kinds of human hepatoma cell lines, SK-Hep-1 and Hep3B, to investigate the cytotoxic effects and the involved mechanisms of small Fe3O4 NPs with different diameters (6 nm, 9 nm, and 14 nm. Results showed that the size of NPs effectively influences the cytotoxicity of hepatoma cells: 6 nm Fe3O4 NPs exhibited negligible cytotoxicity and 9 nm Fe3O4 NPs affected cytotoxicity via cellular mitochondrial dysfunction and by inducing necrosis mediated through the mitochondria-dependent intracellular reactive oxygen species generation. Meanwhile, 14 nm Fe3O4 NPs induced cytotoxicity by impairing the integrity of plasma membrane and promoting massive lactate dehydrogenase leakage. These results explain the detailed mechanism of different diameters of small Fe3O4 NPs-induced cytotoxicity. We anticipate that this study will provide different insights into the cytotoxicity mechanism of Fe3O4 NPs, so as to make them safer to use in clinical application. Keywords: hepatoma cells, nanoparticles, cytotoxicity, mechanism, oxidative stress

Up-regulation of hepatoma-derived growth factor facilitates tumor progression in malignant melanoma [corrected].

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Han-En Tsai

Full Text Available Cutaneous malignant melanoma is the fastest increasing malignancy in humans. Hepatoma-derived growth factor (HDGF is a novel growth factor identified from human hepatoma cell line. HDGF overexpression is correlated with poor prognosis in various types of cancer including melanoma. However, the underlying mechanism of HDGF overexpression in developing melanoma remains unclear. In this study, human melanoma cell lines (A375, A2058, MEL-RM and MM200 showed higher levels of HDGF gene expression, whereas human epidermal melanocytes (HEMn expressed less. Exogenous application of HDGF stimulated colony formation and invasion of human melanoma cells. Moreover, HDGF overexpression stimulated the degree of invasion and colony formation of B16-F10 melanoma cells whereas HDGF knockdown exerted opposite effects in vitro. To evaluate the effects of HDGF on tumour growth and metastasis in vivo, syngeneic mouse melanoma and metastatic melanoma models were performed by manipulating the gene expression of HDGF in melanoma cells. It was found that mice injected with HDGF-overexpressing melanoma cells had greater tumour growth and higher metastatic capability. In contrast, mice implanted with HDGF-depleted melanoma cells exhibited reduced tumor burden and lung metastasis. Histological analysis of excised tumors revealed higher degree of cell proliferation and neovascularization in HDGF-overexpressing melanoma. The present study provides evidence that HDGF promotes tumor progression of melanoma and targeting HDGF may constitute a novel strategy for the treatment of melanoma.

Iso-suillin isolated from Suillus luteus, induces G1 phase arrest and apoptosis in human hepatoma SMMC-7721 cells.

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Jia, Zhi-Qiang; Chen, Ying; Yan, Yong-Xin; Zhao, Jun-Xia

2014-01-01

Iso-suillin, a natural product isolated from Suillus luteus, has been shown to inhibit the growth of some cancer cell lines. However, the molecular mechanisms of action of this compound are poorly understood. The purpose of this study was to investigate how iso-suillin inhibits proliferation and induces apoptosis in a human hepatoma cell line (SMMC-7721). We demonstrated the effects of iso-suillin on cell proliferation and apoptosis in SMMC-7721 cells, with no apparent toxicity in normal human lymphocytes, using colony formation assays and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. Western blotting was used to examine the expression of G1 phase-regulated and apoptosis-associated protein levels in iso-suillin treated SMMC-7721 cells. The results indicated that iso-suillin significantly decreased viability, induced G1 phase arrest and triggered apoptosis in SMMC-7721cells. Taken together, these results suggest the potential of iso-suillin as a candidate for liver cancer treatment.

Niclosamide suppresses hepatoma cell proliferation via the Wnt pathway

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Tomizawa M

2013-11-01

Full Text Available Minoru Tomizawa,1 Fuminobu Shinozaki,2 Yasufumi Motoyoshi,3 Takao Sugiyama,4 Shigenori Yamamoto,5 Makoto Sueishi,4 Takanobu Yoshida6 1Department of Gastroenterology, 2Department of Radiology, 3Department of Neurology, 4Department of Rheumatology, 5Department of Pediatrics, 6Department of Internal Medicine, National Hospital Organization Shimoshizu Hospital, Yotsukaido City, Chiba, Japan Background: The Wnt pathway plays an important role in hepatocarcinogenesis. We analyzed the association of the Wnt pathway with the proliferation of hepatoma cells using Wnt3a and niclosamide, a drug used to treat tapeworm infection. Methods: We performed an MTS assay to determine whether Wnt3a stimulated proliferation of Huh-6 and Hep3B human hepatoma cell lines after 72 hours of incubation with Wnt3a in serum-free medium. The cells were subjected to hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL after 48 hours of incubation. RNA was isolated 48 hours after addition of Wnt3a or niclosamide, and cyclin D1 expression levels were analyzed by real-time quantitative polymerase chain reaction. The promoter activity of T-cell factor was analyzed by luciferase assay 48 hours after transfection of TOPflash. Western blot analysis was performed with antibodies against β-catenin, dishevelled 2, and cyclin D1. Results: Cell proliferation increased with Wnt3a. Niclosamide suppressed proliferation with or without Wnt3a. Hematoxylin and eosin and TUNEL staining suggested that apoptosis occurred in cells with niclosamide. Cyclin D1 was upregulated in the presence of Wnt3a and downregulated with addition of niclosamide. The promoter activity of T-cell factor increased with Wnt3a, whereas T-cell factor promoter activity decreased with niclosamide. Western blot analysis showed that Wnt3a upregulated β-catenin, dishevelled 2, and cyclin D1, while niclosamide downregulated them. Conclusion: Niclosamide is a potential

Computed tomographic evaluation of the portal vein in the hepatomas

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Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam [Hanyang University College of Medicine, Seoul (Korea, Republic of)

1986-10-15

Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

Computed tomographic evaluation of the portal vein in the hepatomas

International Nuclear Information System (INIS)

Lee, Kee Hyung; Lee, Seung Chul; Bae, Man Gil; Seo, Heung Suk; Kim, Soon Yong; Lee, Min Ho; Kee, Choon Suhk; Park, Kyung Nam

1986-01-01

Computed tomography and pornographic findings of 63 patients with hepatoma, undergone hepatic angiography and superior mesenteric pornography for evaluation of tumor and thrombosis of portal vein and determination of indication of transcatheter arterial embolization for palliative treatment of hepatoma from April, 85 to June, 86 in Hanyang university hospital, were reviewed. The results were as follows: 1. In 36 cases, portal vein thrombosis was detected during photography. Nineteen of 37 cases which revealed localized hepatoma in the right lobe of the liver showed portal vein thrombosis; 9 of 11 cases of the left lobe; 8 of 14 cases which were involved in entire liver revealed thrombosis. One case localized in the caudate lobe showed no evidence of invasion to portal vein. 2. Twenty-four of 34 cases with diffuse infiltrative hepatoma revealed portal vein thrombosis and the incidence of portal vein thrombosis in this type were higher than in the cases of the nodular type. 3. The portal vein thrombosis appeared as filling defects of low density in the lumen of the portal veins in CT and they did not reveal contrast enhancement. 4. CT revealed well the evidence of obstructions in the cases of portal vein thrombosis and the findings were well-corresponded to the findings of the superior mesenteric photography. 5. Five of the cases of the portal vein thrombosis were missed in the CT and the causes were considered as due to partial volume effect of enhanced portal vein with partial occlusion or arterioportal shunts. 6. Six of 13 cases with occlusion of main portal vein showed cavernous transformation and they were noted as multiple small enhanced vascularities around the porta hepatis in the CT. According to the results, we conclude that CT is a useful modality to detect the changes of the portal veins in the patients of the hepatoma.

Modulation of human multidrug-resistance MDR-1 gene by natural curcuminoids

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Buddhasukh Duang

2004-04-01

Full Text Available Abstract Background Multidrug resistance (MDR is a phenomenon that is often associated with decreased intracellular drug accumulation in patient's tumor cells resulting from enhanced drug efflux. It is related to the overexpression of a membrane protein, P-glycoprotein (Pgp-170, thereby reducing drug cytotoxicity. A variety of studies have tried to find MDR modulators which increase drug accumulation in cancer cells. Methods In this study, natural curcuminoids, pure curcumin, demethoxycurcumin and bisdemethoxycurcumin, isolated from turmeric (Curcuma longa Linn, were compared for their potential ability to modulate the human MDR-1 gene expression in multidrug resistant human cervical carcinoma cell line, KB-V1 by Western blot analysis and RT-PCR. Results Western blot analysis and RT-PCR showed that all the three curcuminoids inhibited MDR-1 gene expression, and bisdemethoxycurcumin produced maximum effect. In additional studies we found that commercial grade curcuminoid (approximately 77% curcumin, 17% demethoxycurcumin and 3% bisdemthoxycurcumin decreased MDR-1 gene expression in a dose dependent manner and had about the same potent inhibitory effect on MDR-1 gene expression as our natural curcuminoid mixtures. Conclusion These results indicate that bisdemethoxycurcumin is the most active of the curcuminoids present in turmeric for modulation of MDR-1 gene. Treatment of drug resistant KB-V1 cells with curcumin increased their sensitivity to vinblastine, which was consistent with a decreased MDR-1 gene product, a P-glycoprotein, on the cell plasma membrane. Although many drugs that prevent the P-glycoprotein function have been reported, this report describes the inhibition of MDR-1 expression by a phytochemical. The modulation of MDR-1 expression may be an attractive target for new chemosensitizing agents.

Modulation of human multidrug-resistance MDR-1 gene by natural curcuminoids

International Nuclear Information System (INIS)

Limtrakul, Pornngarm; Anuchapreeda, Songyot; Buddhasukh, Duang

2004-01-01

Multidrug resistance (MDR) is a phenomenon that is often associated with decreased intracellular drug accumulation in patient's tumor cells resulting from enhanced drug efflux. It is related to the overexpression of a membrane protein, P-glycoprotein (Pgp-170), thereby reducing drug cytotoxicity. A variety of studies have tried to find MDR modulators which increase drug accumulation in cancer cells. In this study, natural curcuminoids, pure curcumin, demethoxycurcumin and bisdemethoxycurcumin, isolated from turmeric (Curcuma longa Linn), were compared for their potential ability to modulate the human MDR-1 gene expression in multidrug resistant human cervical carcinoma cell line, KB-V1 by Western blot analysis and RT-PCR. Western blot analysis and RT-PCR showed that all the three curcuminoids inhibited MDR-1 gene expression, and bisdemethoxycurcumin produced maximum effect. In additional studies we found that commercial grade curcuminoid (approximately 77% curcumin, 17% demethoxycurcumin and 3% bisdemthoxycurcumin) decreased MDR-1 gene expression in a dose dependent manner and had about the same potent inhibitory effect on MDR-1 gene expression as our natural curcuminoid mixtures. These results indicate that bisdemethoxycurcumin is the most active of the curcuminoids present in turmeric for modulation of MDR-1 gene. Treatment of drug resistant KB-V1 cells with curcumin increased their sensitivity to vinblastine, which was consistent with a decreased MDR-1 gene product, a P-glycoprotein, on the cell plasma membrane. Although many drugs that prevent the P-glycoprotein function have been reported, this report describes the inhibition of MDR-1 expression by a phytochemical. The modulation of MDR-1 expression may be an attractive target for new chemosensitizing agents

Bioactive chemical constituents of Curcuma longa L. rhizomes extract inhibit the growth of human hepatoma cell line (HepG2).

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Abdel-Lateef, Ezzat; Mahmoud, Faten; Hammam, Olfat; El-Ahwany, Eman; El-Wakil, Eman; Kandil, Sherihan; Abu Taleb, Hoda; El-Sayed, Mortada; Hassenein, Hanaa

2016-09-01

The present study was designed to identify the chemical constituents of the methanolic extract of Curcuma longa L. rhizomes and their inhibitory effect on a hepatoma cell line. The methanolic extract was subjected to GC-MS analysis to identify the volatile constituents and the other part of the same extract was subjected to liquid column chromatographic separation to isolate curcumin. The inhibition of cell growth in the hepatoma cell line and the cytopathological changes were studied. GC-MS analysis showed the presence of fifty compounds in the methanolic extract of C. longa. The major compounds were ar-turmerone (20.50 %), β-sesquiphellandrene (5.20 %) and curcumenol (5.11 %). Curcumin was identified using IR, 1H and 13C NMR. The inhibition of cell growth by curcumin (IC50 = 41.69 ± 2.87 μg mL-1) was much more effective than that of methanolic extract (IC50 = 196.12 ± 5.25 μg mL-1). Degenerative and apoptotic changes were more evident in curcumin- treated hepatoma cells than in those treated with the methanol extract. Antitumor potential of the methanolic extract may be attributed to the presence of sesquiterpenes and phenolic constituents including curcumin (0.051 %, 511.39 μg g-1 dried methanol extract) in C. longa rhizomes.

Preparation of a radioactive boron compound (B-I-131-lipiodol) for neutron capture therapy of hepatoma

International Nuclear Information System (INIS)

Chou, F.I.; Chung, H.P.; Chung, R.J.; Wen, H.W.; Wei, Y.Y.; Kai, J.J.; Lui, W.Y.; Chi, C.W.

2000-01-01

In our research, a radioactive boron compound, B-I-131-lipiodol, that can be selectively retained in hepatoma cells was prepared. Combining the effect of α particles produced by boron neutron capture reaction with the β particles released by radionuclides in the radioactive boron compounds will produce a synergistic killing effect on cancer cells. Human hepatoma HepG2 cell cultures were used to examine the stability and the intracellular distribution of the radioactive boron drug. Microscopes were used to examine the interaction and retention of B-I-131-lipiodol globules in the individual hepatoma cell. Moreover, ICP-AES and NaI scintillation counter were performed to determine boron concentrations and I-131 radioactivity, respectively. Results showed that B-I-131-lipiodol with a boron concentration and a specific radioactivity ranged from 500-2000 ppm and 0.05-10 mCi/mL respectively was stably retained in serum. The radiochemical purity of B-I-131-lipiodol was 98%. After supplement with a medium containing B-I-131-lipiodol, the HepG2 cells had intracellular B-I-131-lipiodol globules in the cytoplasm as seen by inverted light microscope, the I-131 and boron can be stably retained in HepG2 cells. (author)

Multidrug resistance in Lactococcus lactis

NARCIS (Netherlands)

Bolhuis, Hendrik

1996-01-01

Multidrug resistance (MDR) was initially recongnized as the major cause of the failure of the drug-based treatment of human cancers. It has become increasingly clear that MDR occurs in mammalian cells but also in lower eukaryotes and bacteria. The appearance of multiple antibiotic resistant

A case report of hepatoma with cystic calcification

Energy Technology Data Exchange (ETDEWEB)

Jeon, Byung Hee; Choi, Sung Wook; Kim, Byung So [Busan National University College of Medicine, Busan (Korea, Republic of)

1974-10-15

A case of hepatoma with cystic calcification radiographically which confirmed by pathological examination, was reported. The patients was 19 years old boy who had abdominal mass and pain in left upper quadrant for 1 month. His family history was not contributary. The upper G-I series revealed slight posterior displacement of the fundus with a cyst like calcification, about 4.5 X 5 cm, in diameter at the left upper quadrant. Liver scanning showed normal concentration of 198{sup A}u on the right lobe but nonvisualization of the left lobe area. Biopsy specimen showed hepatoma cells invading the portal vein and intrahepatic blood vessels, and the cystic structure which was a blood vessel invaded by the tumor consisting of the organized thrombi.

99Tcm pertechnetate uptake by hepatoma cells induced by tissue specific hNIS gene expression

International Nuclear Information System (INIS)

Chen Libo; Luo Quanyong; Yu Yongli; Yuan Zhibin; Lu Hankui; Zhu Ruisen; Guo Lihe

2007-01-01

Objective: Human sodium/iodide symporter (hNIS) gene could be used both as an ideal reporter gene and promising therapeutic gene. Rather than radioiodine, 99 Tc m pertechnetate has been proven to be a better radiopharmaceutical for tracing and imaging purposes. Herein, the authors investigated the feasibility of monitoring hNIS gene expression in hepatoma cells using 99 Tc m pertechnetate as a tracer. Methods: Hepatoma cells MH3924A were stably transfected with recombinant retroviral vector in which hNIS cDNA was driven by murine albumin enhancer/promoter (mAlb) and coupled to hygromycin resistance gene. The uptake and efflux of 99 Tc m pertechnetate by transfected hepatoma cells were tested with 99 Tc m pertechnetate (74 kBq) solution adulterated into the culture media and counted after media suspension discharge at different intervals. In further tests, 50 μmol/L NaClO 4 and 500 μmol/L Ouabain were added into the media for 99 Tc m inhibition tests. For in vive studies, five ACI rats bearing NIS transfected hepatoma xenografts were injected with 99 Tc m pertechnetate (15.8 MBq) and followed by dynamic acquisition (0.57 1, 2 and 4 h) with small gamma camera to semi-quantitatively analyze the radioactivity distribution. Results: In vitro tests, the peak uptake of 99 Tc m pertechnetate by cultured transfected MH3924A cells was up to 254 folds higher than that by the wild type cells. 99 Tc m uptake by transfected cells were significantly inhibited by NaClO 4 down to 2.44% (P 99 Tc m pertechnetate out of cultured transfected cells became rapid immediately after renewal of culture media (half life 99 Tc m accumulations by hNIS transfected tumor xenografts were obvious in early phases of the acquisition with peak uptake at 12 min and gradually declining later on. Conclusions: hNIS transfected hepatoma cells can avidly uptake 99 Tc m pertechnetate both in vitro and in vive. It is feasible to utilize 99 Tc m pertechnetate for monitoring and even quantitatively analyzing

A Role for CD81 and Hepatitis C Virus in Hepatoma Mobility

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Claire L. Brimacombe

2014-03-01

Full Text Available Tetraspanins are a family of small proteins that interact with themselves, host transmembrane and cytosolic proteins to form tetraspanin enriched microdomains (TEMs that regulate important cellular functions. Several tetraspanin family members are linked to tumorigenesis. Hepatocellular carcinoma (HCC is an increasing global health burden, in part due to the increasing prevalence of hepatitis C virus (HCV associated HCC. The tetraspanin CD81 is an essential receptor for HCV, however, its role in hepatoma biology is uncertain. We demonstrate that antibody engagement of CD81 promotes hepatoma spread, which is limited by HCV infection, in an actin-dependent manner and identify an essential role for the C-terminal interaction with Ezrin-Radixin-Moesin (ERM proteins in this process. We show enhanced hepatoma migration and invasion following expression of CD81 and a reduction in invasive potential upon CD81 silencing. In addition, we reveal poorly differentiated HCC express significantly higher levels of CD81 compared to adjacent non-tumor tissue. In summary, these data support a role for CD81 in regulating hepatoma mobility and propose CD81 as a tumour promoter.

The experimental study on the radioimmunotherapy of the hepatoma in nude mice model with intratumoral injection of 131I-human anti-HBsAg Fab

International Nuclear Information System (INIS)

Luo Rongcheng; Wu Guichen; Han Huanxing; You Changxuan; Ding Xuemei; Li Aimin; Wang Chuanbin; Zhang Mingjiang

2001-01-01

Objective: To study the therapeutic efficacy of radioimmunotherapy of 131 I-human anti-HBsAg Fab via different routes of administration. Methods: The human hepatoma bearing nude mice we reinjected with 131 I-human anti-HBsAg Fab intra-tumor (IT) and intra-peritoneum (IP). Biodistribution was measured on the 5th day. The tumor growth inhibition rate was determined by measurement of tumor volume. Results: In the IT-treated mice, tumor uptake of 131 I-human anti-HBsAg Fab was four-fold greater than in the IP-treated mice, and normal organ uptake was half of that in the IP-treated mice. At the 3rd week after the infusion, the tumor growth inhibition rate in IT-treated mice was higher than that in the IP-treated mice. Conclusions: Intratumoral administration of 131 I-human anti-HBsAg Fab makes high level of radioactivity retained in tumor with significantly lower radioactivity retained in normal tissues, and provides a more effective regional therapy

Prostaglandin (PG) synthesis by hepatoma cells

International Nuclear Information System (INIS)

Cyran, J.; Lysz, T.W.; Lea, M.A.

1987-01-01

Proliferation of cultured HTC hepatoma cells was reported to be inhibited by indomethacin but synthesis of PG in these cells was no detected. The authors have found that omission of fetal calf serum from the medium permits detection of synthesis of 6-keto-PGF1 alpha, PFG2 alpha, PGE2 and TxB2 from labeled arachidonic acid. Two additional peaks were identified as metabolites of PGF2 alpha and PGE2 by retention times on HPLC. Indomethacin inhibited the formation of the PGs and the metabolites. When 3 H-PGE2 and 3 H-PGF2 alpha were added to the cultures, approximately 50% of the label was recovered as the PG metabolites after a 4 day incubation. Metabolism of 3 H-TxB2 was not detected. When HTC cells were grown in the presence of 100 μM flurbiprofen, a cyclooxygenase inhibitor, there was significant inhibition of both cell proliferation and 3 H-thymidine uptake. The authors data suggest that proliferation of hepatoma cells is facilitated by synthesis of PGs

Preliminary result in patients with primary hepatoma treated by stereotactic radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Kang, Ki Mun; Choi, Ihl Bohng; Kim, In Ah; Choi, Byung Ock; Kang, Young Nam; Han, Sung Tae; Chung, Gyu Won [College of Medicine, Catholic Univ., Seoul (Korea, Republic of); Chai, Gyu Young [College of Medicine, Gyeongsang National Univ., Chinju (Korea, Republic of)

2001-03-01

It is not common to evaluate the response of the fractionated stereotactic radiotherapy (SRT) to primary hepatoma as compared with conventional radiotherapy. The purpose of the study was to take the preliminary result on the clinical trial of primary hepatoma by SRT. From July 1999 to March 2000, thirty three patients were hospitalized in the St. Mary's Hospital, and treated with SRT for extracranial tumors. Among them, 13 patients were diagnosed to primary hepatoma and then applied by frameless SRT using 6 MV linac accelerator. There were 12 male and 1 female patients. They had the age of 44-66 year old (median: 59) and the tumor size of 10-825 cc (median: 185 cc). SRT was given to them 3-5 fractions a week (5 Gy/fraction, 90% isodose line) for 2-3 weeks. Median dose of SRT was 50 Gy and the range was 30-50 Gy. Follow-up period ranged from 3 months to 13 months with median of 8 months. After treating SRT to thirteen patients with primary hepatoma, the response of the tumor was examined by abdominal CT: they are classified by 1 complete regression (7.7%), 7 partial regression (53.8%), 4 minimal regression (30.8%), 1 stable disease (7.7%). The positive responses more than partial remission were 8 patients (61.5%) after the treatment. The level of serum alpha-fetoprotein (AFP) after the treatment as compared with pretreatment had been 92.3% decreased. There was no severe complication except dyspepsia 84.6%, mild nausea 69.2%, transient decreased of hepatic function 15.4% and fever 7.7%. SRT to the patients with primary hepatoma was potentially suggested to become the safe and more effective tool than the conventional radiotherapy even though there were relatively short duration of follow-up and small numbers to be tested.

Detection and characterisation of multi-drug resistance protein 1 (MRP-1) in human mitochondria.

Science.gov (United States)

Roundhill, E A; Burchill, S A

2012-03-13

Overexpression of plasma membrane multi-drug resistance protein 1 (MRP-1) can lead to multidrug resistance. In this study, we describe for the first time the expression of mitochondrial MRP-1 in untreated human normal and cancer cells and tissues. MRP-1 expression and subcellular localisation in normal and cancer cells and tissues was examined by differential centrifugation and western blotting, and immunofluorescence microscopy. Viable mitochondria were isolated and MRP-1 efflux activity measured using the calcein-AM functional assay. MRP-1 expression was increased using retroviral infection and specific overexpression confirmed by RNA array. Cell viability was determined by trypan blue exclusion and annexin V-propidium iodide labelling of cells. MRP-1 was detected in the mitochondria of cancer and normal cells and tissues. The efflux activity of mitochondrial MRP-1 was more efficient (55-64%) than that of plasma membrane MRP-1 (11-22%; PMRP-1 expression resulted in a preferential increase in mitochondrial MRP-1, suggesting selective targeting to this organelle. Treatment with a non-lethal concentration of doxorubicin (0.85 nM, 8 h) increased mitochondrial and plasma membrane MRP-1, increasing resistance to MRP-1 substrates. For the first time, we have identified MRP-1 with efflux activity in human mitochondria. Mitochondrial MRP-1 may be an exciting new therapeutic target where historically MRP-1 inhibitor strategies have limited clinical success.

Expression of 65-kDa oncofetal protein in experimental hepatoma after antivancer therapy

International Nuclear Information System (INIS)

Mirowski, M.; Rozalski, M.; Krajewska, U.; Wierbicki, R.; Hanausek, M.

1997-01-01

We have tested the expression of 65-kDa oncofetal protein (p65) after combined treatment with menadione and methotrexate in hamsters transplanted with Kirkman-Robbins hepatoma. The treatment of tumor-bearing animals with these compounds significantly inhibited both the tumor development and the expression of p65. This inhibition in tumor tissue was calculated from densitograms of Western blots. The inhibition of p65 was also confirmed in the serum of hepatoma bearing animals by using solid-phase radioimmunoassay (RIA) to quantify the specificity of polyclonal antibodies to fetal p65 molecules. Additionally, p65 was shown to localize both in cytoplasm an in the nuclear extracts prepared from hepatoma tissue. (author)

Chylomicron remnant-vitamin A metabolism by the human hepatoma cell line HepG2

International Nuclear Information System (INIS)

Lenich, C.M.

1985-01-01

The binding and metabolism of [ 3 H] vitamin A-containing chylomicron remnants (CMR) by the human hepatoma cell line Hep G2 was studied. Mesenteric lymph chylomicrons (CM) were collected from [ 3 H] retinol-fed rats and incubated with lipoprotein-lipase to obtain CMR. At 4 0 C, specific CMR binding was inhibited by excess unlabeled CMR. Specific binding predominated at low concentrations and approached saturation while total binding continued to increase over an extensive concentration range (0.45-32 μg triglyceride/ml). CMR uptake at 37 0 C was greater than that of CM and at least 100 times more efficient than the fluid-phase pinocytosis of sucrose. CMR binding increased as the extent of lipolysis obtained by incubation with lipoprotein-lipase increased. Addition of human apolipoprotein E enhanced both CMR and CM binding. After internalization, Hep G2 cells hydrolyzed CMR-[ 3 H]retinyl esters and radiolabeled metabolites accumulated as a function of time and temperature. As a function of the concentration of [ 3 H] VA initially cell-bound, retinol and retinyl esters accumulated as the major cell-associated metabolites. By contrast, retinol was the major metabolite in the medium only at low VA concentrations as other more polar metabolites accumulated at higher concentrations (> 110 pmol VA/mg cell protein). The accumulation of CMR-VA metabolites in the medium was reduced when cells were preincubated in retinol-supplemented media. Also, the specific activity of retinol in the medium closely resembled that in the cell indicating that CMR-VA mixed with the cellular store prior to its secretion

The concentration of cadmium in hepatoma among Filipinos

International Nuclear Information System (INIS)

Alejandrino, A.L.; Goze, C.B.; Paradero, R.R.

1977-08-01

The concentration of cadmium in liver hepatoma and in normal liver in Filipinos was determined by atomic absorption spectrophotometry. Using NBS Bovine Liver (SRM1577) as reference material, a value of 0.28+-0.025 ug/g dry weight was obtained for cadmium which is close to the certified NBS value of 0.27+-0.04 ug/g. The mean percentage recovery for cadmium determination by AAS was 98.38%. A mean value of 2.14+-1.58 ug Cd/g liver hepatoma was observed for the 12 cases investigated, showing decreased cadmium levels in the cancerous liver compared to the mean value of 12.62 ug Cd/g observed for normal liver obtained from 10 cases of accidental deaths. The values are expressed on a dry weight basis

The synergistic radiosensitizing effect of tirapazamine-conjugated gold nanoparticles on human hepatoma HepG2 cells under X-ray irradiation

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Liu X

2016-07-01

Full Text Available Xi Liu,1–4 Yan Liu,1–4 Pengcheng Zhang,1–4 Xiaodong Jin,1–3 Xiaogang Zheng,1–4 Fei Ye,1–4 Weiqiang Chen,1–3 Qiang Li1–3 1Institute of Modern Physics, 2Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, 3Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Gansu Province, Lanzhou, 4School of Life Science, University of Chinese Academy of Sciences, Beijing, People’s Republic of China Abstract: Reductive drug-functionalized gold nanoparticles (AuNPs have been proposed to enhance the damage of X-rays to cells through improving hydroxyl radical production by secondary electrons. In this work, polyethylene glycol-capped AuNPs were conjugated with tirapazamine (TPZ moiety, and then thioctyl TPZ (TPZs-modified AuNPs (TPZs-AuNPs were synthesized. The TPZs-AuNPs were characterized by transmission electron microscopy, ultraviolet-visible spectra, dynamic light scattering, and inductively coupled plasma mass spectrometry to have a size of 16.6±2.1 nm in diameter and a TPZs/AuNPs ratio of ~700:1. In contrast with PEGylated AuNPs, the as-synthesized TPZs-AuNPs exhibited 20% increment in hydroxyl radical production in water at 2.0 Gy, and 19% increase in sensitizer enhancement ratio at 10% survival fraction for human hepatoma HepG2 cells under X-ray irradiation. The production of reactive oxygen species in HepG2 cells exposed to X-rays in vitro demonstrated a synergistic radiosensitizing effect of AuNPs and TPZ moiety. Thus, the reductive drug-conjugated TPZs-AuNPs as a kind of AuNP radiosensitizer with low gold loading provide a new strategy for enhancing the efficacy of radiation therapy. Keywords: AuNPs, radiation enhancement, synergistic effect, human hepatoma cells, hydroxyl radical production

Elemental trace analysis of hepatomas and normal tissues by proton induced x-ray emission spectroscopy

International Nuclear Information System (INIS)

Matsuzawa, Taiju; Shishido, Fumio; Sera, Koichiro; Sato, Tachio; Morita, Tasuku.

1977-01-01

Specimens taken from liver, brain, serum and ascites hepatoma 130 in rats, were bombarded with 3.5 MeV protons accelerated by a Van de graaff generator, and the induced x-ray fluorescence was analysed with a Si(Li) detector. Absolute concentrations were determined with reference to a known concentration of uranium in the specimen. Small amounts of Ga, Yb and Tl which are known as metals having tumor affinity were injected into rats implanted with ascites hepatoma and several of its derivatives. Twenty-four hours after injection, liver, brain, serum and hepatoma were removed from the rats and these specimens were analysed by the same method. Relative concentrations of Fe, Cu, Zn and Br in liver, brain, serum and hepatoma specimens showed characteristic patterns. Patterns of liver and ascites hepatoma were quite similar, but the total amount of metals in liver was greater. The serum contained a large quantity of Br. Each AH 130 tumor cell line and its derivatives showed a different accumulation rate for Ga, Yb and Tl. Tl accumulated peculiarly in the brain. There was excellent co-relation between the concentrations of the elements and the biological characteristics of the tumor. (Evans, J.)

188Re-SSS lipiodol: radiolabelling and biodistribution following injection into the hepatic artery of rats bearing hepatoma.

Science.gov (United States)

Garin, Etienne; Denizot, Benoit; Noiret, Nicolas; Lepareur, Nicolas; Roux, Jerome; Moreau, Myriam; Herry, Jean-Yves; Bourguet, Patrick; Benoit, Jean-Pierre; Lejeune, Jean-Jacques

2004-10-01

Although intra-arterial radiation therapy with 131I-lipiodol is a useful therapeutic approach to the treatment of hepatocellular carcinoma, various disadvantages limit its use. To describe the development of a method for the labelling of lipiodol with 188Re-SSS (188Re (S2CPh)(S3CPh)2 complex) and to investigate its biodistribution after injection into the hepatic artery of rats with hepatoma. 188Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 188Re, in cold lipiodol. The radiochemical purity (RCP) of labelling was checked immediately. The 188Re-SSS lipiodol was injected into the hepatic artery of nine rats with a Novikoff hepatoma. They were sacrificed 1, 24 and 48 h after injection, and used for ex vivo counting. Labelling of 188Re-SSS lipiodol was achieved with a yield of 97.3+/-2.1%. The immediate RCP was 94.1+/-1.7%. Ex vivo counting confirmed a predominantly hepatic uptake, with a good tumoral retention of 188Re-SSS lipiodol, a weak pulmonary uptake and a very faint digestive uptake. The 'tumour/non-tumoral liver' ratio was high at 1, 24 and 48 h after injection (2.9+/-1.5, 4.1+/-/4.1 and 4.1+/-0.7, respectively). Using the method described here, 188Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. The biodistribution in rats with hepatoma indicates a good tumoral retention of 188Re-SSS lipiodol associated with a predominant hepatic uptake, a weak pulmonary uptake and a very faint digestive uptake. This product should be considered for intra-arterial radiation therapy in human hepatoma.

The involvement of splenic artery in the blood supply of hepatomas: its DSA findings and interventional treatment

International Nuclear Information System (INIS)

Duan Xuhua; Liang Huiming; Feng Gansheng; Zheng Chuangsheng; Ren Jianzhuang

2009-01-01

Objective: To investigate the DSA manifestations of the involvement of splenic artery in supplying blood to hepatomas and to assess the therapeutic value of super-selective interventional embolization. Methods: During the period of March 2005-June 2008, 897 patients with hepatoma underwent angiography and the involvement of splenic artery in the blood supply of hepatoma was confirmed in 7 cases. Splenic arteriography was performed by means of super-selective catheterization with 5 F Yashiro catheter together with 3 F SP catheter. The splenic arteries which supplied blood to hepatomas were embolized with hyper-liquid iodized-oil emulsion mixed with chemotherapy drug, which was followed by the injection of sufficient gelatin sponge or ethanol. The clinical results were analyzed. Results: Splenic arteriography revealed that the splenic artery was the main supplying vessel of the hepatoma in two cases, and was not the main supplying vessel of the hepatoma in five cases. The splenic supplying vessels were completely embolized in all 7 cases. After the procedure, AFP level was decreased over 50%, and in two patients it dropped to normal. CT checkup 4-6 weeks after the surgery revealed that the diameter of tumor decreased to 2.5 - 4.6 cm. Conclusion: The involvement of splenic artery in supplying blood to hepatomas is not common. Super-selective catheterization and sufficient embolization of the splenic supplying vessels are very important for improving the interventional effectiveness. (authors)

Diagnosis of hepatoma using grayscale and Doppler ultrasound in patients with chronic liver disease

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Idris S

2011-10-01

Full Text Available Wasim A Memon, Zishan Haider, Mirza Amanullah Beg, Muhammad Idris, Tanveer-ul-Haq, Waseem Akhtar, Sidra IdrisRadiology Department, Aga Khan University Hospital, Karachi, Pakistan Every author contributed equally to the workObjective: To determine the diagnostic accuracy of liver ultrasound for the detection of hepatoma in chronic liver disease (CLD patients by either taking histopathology or serum α-fetoprotein levels or a biphasic computed tomography (CT scan (whichever is available as the gold standard.Study design: Cross-sectional.Place and duration of study: Radiology Department, The Aga Khan University Hospital, Karachi, Pakistan, from January 2007 to January 2010.Methods: A total of 239 patients (156 males and 83 females with clinical suspicion or surveillance of hepatoma in CLD referred to the radiology department for ultrasound evaluation followed by either liver biopsy and histopathology or serum α-fetoprotein level or biphasic CT scan.Results: The sensitivity of ultrasound for hepatoma detection in CLD was 65%, specificity was 85%, and accuracy was 70%, and positive predictive value and negative predictive value were 92% and 45%, respectively.Conclusion: Ultrasound is a relatively quick, safe, reasonably accurate, and noninvasive imaging modality for the detection of hepatoma in CLD and can be complemented with clinical assessment of screening high-risk patients.Keywords: hepatoma, ultrasound, radiology, chronic liver disease

Overexpression of thyroid hormone beta1 nuclear receptor is associated with an increased proliferation of human hepatoma cells

International Nuclear Information System (INIS)

Lin, K.; Lin, Y.; McPhie, P.; Cheng S.

1994-01-01

It is evaluated the expression of thyroid hormone nuclear receptors (TRs) and their possible roles in the carcinogenesis of human hepatocarcinoma. The expression of TRβ and TRα genes was evaluated at both the mRNA and protein levels. The expression of TRβ1 and TRα1 mRNAs is similar to those found in normal liver. However, the expression of TR isoform proteins depends on the cell-type. The expression of TRα1 protein is low in all cell lines examined. However, TRβ1 protein is overexpressed in Mahlavu, SK-Hep-1, and HA22T, moderately expressed in J5, J7, and J328 and is very low in HepG2, Hep3B, and PLC/PRF/5 cells. The proliferation of cells in which TRβ1 is overexpressed is stimulated by the thyroid hormone, 3,3',5-triiodo-L-thyronine. These results suggest that TRβ1 not TRα1, is probably involved in the proliferation of hepatoma cells

Membrane vesicles from multidrug-resistant human carcinoma cells contain a specific 150,000-170,000 dalton protein detected by photoaffinity labeling

International Nuclear Information System (INIS)

Cornwell, M.M.; Safa, A.R.; Felsted, R.L.; Gottesman, M.M.; Pastan, I.

1986-01-01

The authors have selected multidrug-resistant human KB carcinoma cells in high levels of colchicine (KB-C4) or vinblastine (KB-V1) which are cross-resistant to many other structurally unrelated chemotheraputic agents. To determine the mechanism of reduced drug accumulation, they measured 3 H-vinblastine ( 3 H-VBL) association with membrane vesicles made from parental drug sensitive, drug-resistant and revertant cells. Membrane vesicles from highly multidrug resistant cells exhibited increased specific and saturable binding of vinblastine, (Kd = 1 μM) that was temperature dependent and trypsin sensitive. To identify the molecules which bind vinblastine, membrane vesicles were exposed to two photo-activatable analogs of vinblastine, (N-P-(azido-3,5,-[ 3 H]-benzoyl)-N'-β-aminoethylvindisine ( 3 H-NAB) and N-P-(azido-3-[ 125 I]-solicyl)-N'-β-aminoethylvindesine ( 125 I-NASV). The specific labeling of a 150,000-170,000 dalton protein in membrane vesicles from multidrug-resistant KB-C4 and KB-V1 cells was found. 125 I-NASV labeling was inhibited by vinblastine, vincrinstine and verapamil but not by colchicine or dexamethasone. The 150,000-170,000 dalton protein may have an important role in the multidrug resistance phenotype

Multidrug-Resistant Salmonella enterica Serovar Muenchen from Pigs and Humans and Potential Interserovar Transfer of Antimicrobial Resistance

OpenAIRE

Gebreyes, Wondwossen A.; Thakur, Siddhartha

2005-01-01

Salmonella serovars are important reservoirs of antimicrobial resistance. Recently, we reported on multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium strains among pigs with resistance to ampicillin, kanamycin, streptomycin, sulfamethoxazole, and tetracycline (resistance [R] type AKSSuT) and resistance to amoxicillin-clavulanic acid, ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (R type AxACSSuT). In the present study, 67 isolates (39 from humans...

Multidrug Efflux Pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus Bacterial Food Pathogens

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Jody L. Andersen

2015-01-01

Full Text Available Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations.

Multidrug Efflux Pumps from Enterobacteriaceae, Vibrio cholerae and Staphylococcus aureus Bacterial Food Pathogens

Science.gov (United States)

Andersen, Jody L.; He, Gui-Xin; Kakarla, Prathusha; KC, Ranjana; Kumar, Sanath; Lakra, Wazir Singh; Mukherjee, Mun Mun; Ranaweera, Indrika; Shrestha, Ugina; Tran, Thuy; Varela, Manuel F.

2015-01-01

Foodborne illnesses caused by bacterial microorganisms are common worldwide and constitute a serious public health concern. In particular, microorganisms belonging to the Enterobacteriaceae and Vibrionaceae families of Gram-negative bacteria, and to the Staphylococcus genus of Gram-positive bacteria are important causative agents of food poisoning and infection in the gastrointestinal tract of humans. Recently, variants of these bacteria have developed resistance to medically important chemotherapeutic agents. Multidrug resistant Escherichia coli, Salmonella enterica, Vibrio cholerae, Enterobacter spp., and Staphylococcus aureus are becoming increasingly recalcitrant to clinical treatment in human patients. Of the various bacterial resistance mechanisms against antimicrobial agents, multidrug efflux pumps comprise a major cause of multiple drug resistance. These multidrug efflux pump systems reside in the biological membrane of the bacteria and actively extrude antimicrobial agents from bacterial cells. This review article summarizes the evolution of these bacterial drug efflux pump systems from a molecular biological standpoint and provides a framework for future work aimed at reducing the conditions that foster dissemination of these multidrug resistant causative agents through human populations. PMID:25635914

Bacterial Multidrug Efflux Pumps of the Major Facilitator Superfamily as Targets for Modulation.

Science.gov (United States)

Kumar, Sanath; He, Guixin; Kakarla, Prathusha; Shrestha, Ugina; Ranjana, K C; Ranaweera, Indrika; Willmon, T Mark; Barr, Sharla R; Hernandez, Alberto J; Varela, Manuel F

2016-01-01

Causative agents of infectious disease that are multidrug resistant bacterial pathogens represent a serious public health concern due to the increasingly difficult nature of achieving efficacious clinical treatments. Of the various acquired and intrinsic antimicrobial agent resistance determinants, integral-membrane multidrug efflux pumps of the major facilitator superfamily constitute a major mechanism of bacterial resistance. The major facilitator superfamily (MFS) encompasses thousands of known related secondary active and passive solute transporters, including multidrug efflux pumps, from bacteria to humans. This review article addresses recent developments involving the targeting by various modulators of bacterial multidrug efflux pumps from the major facilitator superfamily. It is currently of tremendous interest to modulate bacterial multidrug efflux pumps in order to eventually restore the clinical efficacy of therapeutic agents against recalcitrant bacterial infections. Such MFS multidrug efflux pumps are good targets for modulation.

Repression of the albumin gene in Novikoff hepatoma cells

International Nuclear Information System (INIS)

Capetanaki, Y.G.; Flytzanis, C.N.; Alonso, A.

1982-01-01

Novikoff hepatoma cells have lost their capacity to synthesize albumin. As a first approach to study the mechanisms underlying this event, in vitro translation in a reticulocyte system was performed using total polyadenylated mRNA from rat liver and Novikoff hepatoma cells. Immunoprecipitation of the in vitro translation products with albumin-specific antibody revealed a total lack of albumin synthesis in Novikoff hepatoma, suggesting the absence of functional albumin mRNA in these cells. Titration experiments using as probe albumin cDNA cloned in pBR322 plasmid demonstrated the absence of albumin-specific sequences in both polysomal and nuclear polyadenylated and total RNA from Novikoff cells. This albumin recombinant plasmid was obtained by screening a rat liver cDNA library with albumin [/sup 32/P]cDNA reverse transcribed from immuno-precipitated mRNA. The presence of an albumin-specific gene insert was documented with translation assays as well as by restriction mapping. Repression of the albumin gene at the transcriptional level was further demonstrated by RNA blotting experiments using the cloned albumin cDNA probe. Genomic DNA blots using the cloned albumin cDNA as probe did not reveal any large-scale deletions, insertions, or rearrangements in the albumin gene, suggesting that the processes involved in the suppression of albumin mRNA synthesis do not involve extensive genomic rearrangements

CD44-engineered mesoporous silica nanoparticles for overcoming multidrug resistance in breast cancer

International Nuclear Information System (INIS)

Wang, Xin; Liu, Ying; Wang, Shouju; Shi, Donghong; Zhou, Xianguang; Wang, Chunyan; Wu, Jiang; Zeng, Zhiyong; Li, Yanjun; Sun, Jing; Wang, Jiandong; Zhang, Longjiang; Teng, Zhaogang; Lu, Guangming

2015-01-01

Graphical abstract: - Highlights: • CD44-engineered mesoporous silica nanoparticles are synthesized. • The mechanism of CD44-engineered mesoporous silica nanoparticles is revealed. • This new delivery system increased the drug accumulation in vitro and in vivo. • This new delivery system offers an effective approach to treat multidrug resistance. - Abstract: Multidrug resistance is a major impediment for the successful chemotherapy in breast cancer. CD44 is over-expressed in multidrug resistant human breast cancer cells. CD44 monoclonal antibody exhibits anticancer potential by inhibiting proliferation and regulating P-glycoprotein-mediated drug efflux activity in multidrug resistant cells. Thereby, CD44 monoclonal antibody in combination with chemotherapeutic drug might be result in enhancing chemosensitivity and overcoming multidrug resistance. The purpose of this study is to investigate the effects of the CD44 monoclonal antibody functionalized mesoporous silica nanoparticles containing doxorubicin on human breast resistant cancer MCF-7 cells. The data showed that CD44-modified mesoporous silica nanoparticles increased cytotoxicity and enhanced the downregulation of P-glycoprotein in comparison to CD44 antibody. Moreover, CD44-engineered mesoporous silica nanoparticles provided active target, which promoted more cellular uptake of DOX in the resistant cells and more retention of DOX in tumor tissues than unengineered counterpart. Animal studies of the resistant breast cancer xenografts demonstrated that CD44-engineered drug delivery system remarkably induced apoptosis and inhibited the tumor growth. Our results indicated that the CD44-engineered mesoporous silica nanoparticle-based drug delivery system offers an effective approach to overcome multidrug resistance in human breast cancer

Relationship between P53 and bystander effect induced by radiated hepatoma cells

International Nuclear Information System (INIS)

Zhao Meijia; Shen Bo; Yuan Dexiao; Cheng Honghong; Shao Chunlin

2009-01-01

The role of p53 in bystander responses on normal liver cells were investigated by co-culturing irradiated hepatoma cells with non-irradiated bystander Chang liver cells. It was found that radiosensitivity of the hepatoma cells was relative to p53. HepG2 cells with wtp53 had the highest radiosensitivity followed by PLC/PRF/5 cells with mtp53 and Hep3B cells with null-p53. The induction of bystander micronucleus(MN) was observed only in the Chang liver cells that had been co-cultured with HepG2 cells but not co-cultured with PLC/PRF/5 or Hep3B. Also, this bystander MN was relative to the irradiation dose and the cell co-culture rime. When the hepatoma cells were treated with pifithrin-α, a p53 inhibitor, their radiosensitivities were reduced, and the bystander effect was diminished. The results indicate that p53 could regulate not only the radiosensitivity but also the bystander response. (authors)

Magnetic nanoparticles for targeted therapeutic gene delivery and magnetic-inducing heating on hepatoma

International Nuclear Information System (INIS)

Yuan, Chenyan; Zhang, Jia; Li, Hongbo; Zhang, Hao; Wang, Ling; Zhang, Dongsheng; An, Yanli

2014-01-01

Gene therapy holds great promise for treating cancers, but their clinical applications are being hampered due to uncontrolled gene delivery and expression. To develop a targeted, safe and efficient tumor therapy system, we constructed a tissue-specific suicide gene delivery system by using magnetic nanoparticles (MNPs) as carriers for the combination of gene therapy and hyperthermia on hepatoma. The suicide gene was hepatoma-targeted and hypoxia-enhanced, and the MNPs possessed the ability to elevate temperature to the effective range for tumor hyperthermia as imposed on an alternating magnetic field (AMF). The tumoricidal effects of targeted gene therapy associated with hyperthermia were evaluated in vitro and in vivo. The experiment demonstrated that hyperthermia combined with a targeted gene therapy system proffer an effective tool for tumor therapy with high selectivity and the synergistic effect of hepatoma suppression. (paper)

Structure-activity relationships of diverse xanthones against multidrug resistant human tumor cells.

Science.gov (United States)

Wang, Qiwen; Ma, Chenyao; Ma, Yun; Li, Xiang; Chen, Yong; Chen, Jianwei

2017-02-01

Thirteen xanthones were isolated naturally from the stem of Securidaca inappendiculata Hassk, and structure-activity relationships (SARs) of these compounds were comparatively predicted for their cytotoxic activity against three human multidrug resistant (MDR) cell lines MCF-7/ADR, SMMC-7721/Taxol, and A549/Taxol cells. The results showed that the selected xanthones exhibited different potent cytotoxic activity against the growth of different human tumor cell lines, and most of the xanthones exhibited selective cytotoxicity against SMMC-7721/Taxol cells. Furthermore, some tested xanthones showed stronger cytotoxicity than Cisplatin, which has been used in clinical application extensively. The SARs analysis revealed that the cytotoxic activities of diverse xanthones were affected mostly by the number and position of methoxyl and hydroxyl groups. Xanthones with more free hydroxyl and methoxyl groups increased the cytotoxic activity significantly, especially for those with the presence of C-3 hydroxyl and C-4 methoxyl groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

Release of overexpressed CypB activates ERK signaling through CD147 binding for hepatoma cell resistance to oxidative stress.

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Kim, Kiyoon; Kim, Hunsung; Jeong, Kwon; Jung, Min Hyung; Hahn, Bum-Soo; Yoon, Kyung-Sik; Jin, Byung Kwan; Jahng, Geon-Ho; Kang, Insug; Ha, Joohun; Choe, Wonchae

2012-08-01

Cyclophilin, a cytosolic receptor for the immunosuppressive drug cyclosporin A, plays a role in diverse pathophysiologies along with its receptor, CD147. Although the interaction between cyclophilin A and CD147 is well established in inflammatory disease, that of cyclophilin B (CypB) with CD147 has not been fully explored, especially in cancer cell biology, and the exact molecular mechanism underlying such an association is poorly understood. In this study, we first identified high expression levels of CypB in 54 % of hepatocellular carcinoma patient tissues but in only 12.5 % of normal liver tissues. Then, we demonstrated that CypB overexpression protects human hepatoma cells against oxidative stress through its binding to CD147; this protective effect depends on the peptidyl prolyl isomerase activity of CypB. siRNA-mediated knockdown of CypB expression rendered hepatoma cells more vulnerable to ROS-mediated apoptosis. Furthermore, we also determined that a direct interaction between secreted CypB and CD147 regulates the extracellular signal-regulated kinase intracellular signaling pathway and is indispensible for the protective functions of CypB. For the first time, we demonstrated that CypB has an essential function in protecting hepatoma cells against oxidative stress through binding to CD147 and regulating the ERK pathway.

Effects of a fish oil-based emulsion on rat hepatoma cell invasion in culture.

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Hagi, Akifumi; Nakayama, Mitsuo; Miura, Yutaka; Yagasaki, Kazumi

2007-01-01

Total parenteral nutrition containing a lipid emulsion is often employed after surgical tumor resection. This study investigated the effects of a fish oil-based infusion on rat hepatoma cell invasion. Rat ascites hepatoma cell line AH109A was precultured with a fish oil-based or safflower oil-based emulsion for 48 h. Changes in membranous fatty acid composition were evaluated by gas chromatography. The invasiveness of hepatoma cells was assessed by coculturing with mesentery-derived mesothelial cells. To examine ex vivo effects of the fish oil-based infusion on hepatoma invasion, sera were prepared from rats infused with fish oil- or safflower oil-based emulsion and the effects of these sera were assessed. To clarify the mechanism of inhibition of invasion by the fish oil-based emulsion, the effects of prostaglandin (PG) E(2) and PGE(3) on invasion were examined. Pretreatment with the fish oil-based emulsion reduced invasiveness without affecting growth compared with the safflower oil-based emulsion. Pretreatment with the sera from rats infused with the fish oil-based emulsion also reduced invasiveness compared with the sera from rats infused with the safflower oil-based emulsion. The addition of PGE(2) eliminated the inhibitory effect of the fish oil-based emulsion, and the addition of PGE(3) reduced the invasiveness of hepatoma cells pretreated with the safflower oil-based emulsion. These results suggest that the fish oil-based emulsion may have anti-invasive effects. Changes in the membranous fatty acid composition and consequent changes in the prostaglandins produced may be involved in this inhibitory effect.

Hepatoma targeting peptide conjugated bio-reducible polymer complexed with oncolytic adenovirus for cancer gene therapy.

Science.gov (United States)

Choi, Joung-Woo; Kim, Hyun Ah; Nam, Kihoon; Na, Youjin; Yun, Chae-Ok; Kim, SungWan

2015-12-28

Despite adenovirus (Ad) vector's numerous advantages for cancer gene therapy, such as high ability of endosomal escape, efficient nuclear entry mechanism, and high transduction, and therapeutic efficacy, tumor specific targeting and antiviral immune response still remain as a critical challenge in clinical setting. To overcome these obstacles and achieve cancer-specific targeting, we constructed tumor targeting bioreducible polymer, an arginine grafted bio-reducible polymer (ABP)-PEG-HCBP1, by conjugating PEGylated ABP with HCBP1 peptides which has high affinity and selectivity towards hepatoma. The ABP-PEG-HCBP1-conjugated replication incompetent GFP-expressing ad, (Ad/GFP)-ABP-PEG-HCBP1, showed a hepatoma cancer specific uptake and transduction compared to either naked Ad/GFP or Ad/GFP-ABP. Competition assays demonstrated that Ad/GFP-ABP-PEG-HCBP1-mediated transduction was specifically inhibited by HCBP1 peptide rather than coxsackie and adenovirus receptor specific antibody. In addition, ABP-PEG-HCBP1 can protect biological activity of Ad against serum, and considerably reduced both innate and adaptive immune response against Ad. shMet-expressing oncolytic Ad (oAd; RdB/shMet) complexed with ABP-PEG-HCBP1 delivered oAd efficiently into hepatoma cancer cells. The oAd/ABP-PEG-HCBP1 demonstrated enhanced cancer cell killing efficacy in comparison to oAd/ABP complex. Furthermore, Huh7 and HT1080 cancer cells treated with oAd/shMet-ABP-PEG-HCBP1 complex had significantly decreased Met and VEGF expression in hepatoma cancer, but not in non-hepatoma cancer. In sum, these results suggest that HCBP1-conjugated bioreducible polymer could be used to deliver oncolytic Ad safely and efficiently to treat hepatoma. Copyright © 2015 Elsevier B.V. All rights reserved.

In vitro and in vivo reversal of cancer cell multidrug resistance by the semi-synthetic antibiotic tiamulin.

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Baggetto, L G; Dong, M; Bernaud, J; Espinosa, L; Rigal, D; Bonvallet, R; Marthinet, E

1998-11-01

A large number of multidrug resistance (MDR) modulators, termed chemosensitizers, have been identified from a variety of chemicals, but most have been proven to be clinically toxic. Low concentrations of the pleuromutilin-derived semi-synthetic antibiotic tiamulin (0.1 to 10 microM) sensitized the three highly resistant P-glycoprotein (Pgp)-overexpressing tumor cell lines P388 (murine lymphoid leukemia), AS30-D (rat hepatoma), CEM (human lymphoblastic leukemia), and the barely resistant AS30-D/S cell lines to several MDR-related anticancer drugs. Flow cytometric analysis showed that tiamulin significantly increased the intracellular accumulation of daunomycin. When compared to reference modulating agents such as verapamil and cyclosporin A, tiamulin proved to be 1.1 to 8.3 times more efficient in sensitizing the resistant cell lines. Moreover, when given i.p. (1.6 microg/mg body weight), tiamulin increased the survival rate of adriamycin-treated mice bearing the P388/ADR25 tumor line by 29%. In the presence of an anticancer drug, tiamulin inhibited both ATPase and drug transport activities of Pgp in plasma membranes from tumor cells. Tiamulin is thus a potent chemosensitizer that antagonizes the Pgp-mediated chemoresistance in many tumor cell lines expressing the MDR phenotype at different levels and displays no toxic effects on contractile tissues at active doses, therefore providing the promise for potential clinical applications.

Overexpression of thyroid hormone beta1 nuclear receptor is associated with an increased proliferation of human hepatoma cells

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Lin, K; Lin, Y; McPhie, P [Chang-Gung College of Medicine and Technology, Graduate Institute of Clinical Medicine, Taoyuan (Taiwan, Province of China); Cheng, S [National Cancer Inst., Bethesda, MD (United States)

1994-12-31

It is evaluated the expression of thyroid hormone nuclear receptors (TRs) and their possible roles in the carcinogenesis of human hepatocarcinoma. The expression of TR{beta}1 and TR{alpha} genes was evaluated at both the mRNA and protein levels. The expression of TR{beta}1 and TR{alpha}1 mRNAs is similar to those found in normal liver. However, the expression of TR isoform proteins depends on the cell-type. The expression of TRaplha1 protein is low in all cell lines examined. However, TR{Beta}1 protein is overexpressed in Mahlavu, SK-Hep-1, and HA22T, moderately expressed in J5, J7, and J328 and is very low HepG2, Hep3B, and PLC/PRF/5 cells. The proliferation of cells in which TR{beta}1 is overexpressed is stimulated by the thyroid hormone, 3,3`,5- triiodo-L-thyronine. These results suggest that TR{beta}1, not TR{alpha}1, is probably involved in the prolifaration of hepatoma cells.

Percutaneous hepatic arterial catheterization for infusion chemotherapy in treatment of primary hepatoma

International Nuclear Information System (INIS)

Juhn, Jae Ryang; Chang, Jae Yong; Cha, Seong Sook; Han, Sang Suk; Bae, Cheol; Kim, Sung Rok; Chae, Yoo Soon

1984-01-01

Chemotherapy offers palliative treatment to patient with advanced nonresectable hepatoma. The usefulness of systemic chemotherapy is limited because of serious side reaction and low concentration of drug at tumor. But this problem may be overcome by intraarterial infusion. Nonsurgical percutaneous hepatic arterial catheterization was done in 21 patients with primary hepatoma, and infusion chemotherapy was done in 19 patients who were successful in catheterization. The results were as follows: 1. Selective catheterization of hepatic artery proper, common hepatic artery, and celiac artery were successful in 4, 9 and 4 patients respectively. The success rate of selective catheterization is 80.9% including celiac artery among 21 patients with hepatoma. 2. Simple catheterization method was applied in 14 patients, and catheter exchange and Loop methods were applied in 2 and 1 patient respectively. 3. Complication related to catheterization, such as infection and bleeding on punctured site, intimal injury and dislodgement of catheter were not serious. 4. Drugs were well tolerated without serious toxicity or complication. 5. 3 patients showed objective response and median survival time of treated patients is 2.5 months.

Enhancement of esculetin on Taxol-induced apoptosis in human hepatoma HepG2 cells

International Nuclear Information System (INIS)

Kuo, H.-C.; Lee, H.-J.; Hu, C.-C.; Shun, H.-I; Tseng, T.-H.

2006-01-01

The potential use of low dose chemotherapy has been appealing since lower dosages are more attainable during cancer therapy and cause less toxicity in patients. Combination therapy of Taxol, a promising frontline chemotherapy agent, with natural anti-tumor agents that are considerably less toxic with a capability of activating additional apoptotic signals or inhibiting survival signals may provide a rational molecular basis for novel chemotherapeutic strategies. Esculetin, a well-known lipoxygenase inhibitor, showed an inhibitory effect on the cell cycle progression of HL-60 cells in our previous study. In this report, the effects of a concomitant administration of esculetin and Taxol were investigated in human hepatoma HepG2 cells. Firstly, esculetin alone could exert an antiproliferation effect together with an inhibitory effect on the activation of ERKs and p38 MAPK. As compared to the treatment with Taxol only, a co-administration with esculetin and Taxol could result in a further enhancement of apoptosis as revealed by DNA fragmentation assay and Annexin-V-based assay. Meanwhile, immunoblotting analysis also showed that the co-administration of esculetin and Taxol could increase the expression of Bax and the cytosolic release of cytochrome C and enhance the expression of Fas and Fas ligand while the activation of caspase-8 and caspase-3 was also increased. Finally, the ERK cascade was proven to be involved in the enhancement of esculetin on the Taxol-induced apoptosis

Synthesis of PBAD-lipiodol nanoparticles for combination treatment with boric acid in boron neutron capture therapy for hepatoma in-vitro

International Nuclear Information System (INIS)

Chou, F.I.; Chung, H.P.; Liu, H.M.; Wen, H.W.; Chi, C.W.; Lin, Shanyang; Lui, W.Y.; Kai, J.J.

2006-01-01

This study attempted to increase BNCT efficiency for hepatoma by a combined treatment of phenylboric acid derivative entrapped lipiodol nanoparticles (PBAD-L nanoparticles) with boric acid. The size of PBAD-L nanoparticles were 400-750 nm at the boron concentrations of 0.3-2.7 mg/ml. After 24 hours the boron concentration in PBAD-L nanoparticles treated human hepatoma HepG2 cells was 112 ppm, while that in rat liver Clone 9 cells was 52 ppm. With the use of 25 μg B/ml boric acid, after 6 hours the boron concentration in HepG2 and Clone 9 cells were 75 ppm and 40 ppm, respectively. In a combined treatment, boron concentration in HepG2 cells which were treated with PBAD-L nanoparticles for 18 hours and then combined with boric acid for 6 hours was 158 ppm. After neutron irradiation, the surviving fraction of HepG2 cells treated with PBAD-L nanoparticles was 12.6%, while that in the ones with a combined treatment was 1.3%. In conclusion, the combined treatment provided a higher boron concentration in HepG2 cells than treatments with either PBAD-L nanoparticles or boric acid, resulting in a higher therapeutic efficacy of BNCT in hepatoma cells. (author)

Studies on the Identification of Constituents in Ethanol Extract of Radix Glycyrrhizae and Their Anti-Primary Hepatoma Cell Susceptibility

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Jie Liu

2014-01-01

Full Text Available The objective of this paper is to study the chemical constituents of Radix Glycyrrhizae and to apply the resulting natural products in the study of drug susceptibility of hepatoma cells so as to provide a scientific basis for quality standards and clinical application of medicinal Radix Glycyrrhizae. Chromatographic materials were used for isolation and purification; structural identification was performed based on physicochemical properties and spectral data. MTT colorimetry was used to detect the proliferation inhibition rate against primary hepatoma cells by natural products, and flow cytometry was used to detect the changes in cell cycle progression. Five compounds were isolated and identified, namely, liquiritigenin (1, liquiritin (2, isoliquiritigenin (3, betulinic acid (4, and oleanolic acid (5. In the study, 5-FU (5-fluorouracil is used as a positive control to the hepatoma cells. Primary hepatoma cells were highly susceptible to 5-FU and liquiritigenin, both of which markedly inhibited the proliferation of hepatoma cells; flow cytometry results showed an increase in G0/G1 phase cells, a decrease in S phase cells, and a relative increase in G2/M phase cells. Primary hepatoma cells are highly susceptible to liquiritigenin, a natural product; the testing of tumor cell susceptibility is of important significance to the improvement of therapeutic effect of cancer.

Composition of Lycium barbarum polysaccharides and their apoptosis-inducing effect on human hepatoma SMMC-7721 cells

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Qian Zhang

2015-11-01

Full Text Available Background: Lycium barbarum polysaccharide (LBP is a natural functional component that has a variety of biological activities. The molecular structures and apoptosis-inducing activities on human hepatoma SMMC-7721 cells of two LBP fractions, LBP-d and LBP-e, were investigated. Results: The results showed that LBP-d and LBP-e both consist of protein, uronic acid, and neutral sugars in different proportions. The structure of LBP was characterized by gas chromatography, periodate oxidation, and Smith degradation. LBP-d was composed of eight kinds of monosaccharides (fucose, ribose, rhamnose, arabinose, xylose, mannose, galactose, and glucose, while LBP-e was composed of six kinds of monosaccharides (fucose, rhamnose, arabinose, mannose, galactose, and glucose. LBP-d and LBP-e blocked SMMC-7721 cells at the G0/G1 and S phases with an inhibition ratio of 26.70 and 45.13%, respectively, and enhanced the concentration of Ca2 + in the cytoplasm of SMMC-7721. Conclusion: The contents of protein, uronic acid, and galactose in LBP-e were much higher than those in LBP-d, which might responsible for their different bioactivities. The results showed that LBP can be provided as a potential chemotherapeutic agent drug to treat cancer.

Ginsenoside Rh2 Induces Human Hepatoma Cell Apoptosisvia Bax/Bak Triggered Cytochrome C Release and Caspase-9/Caspase-8 Activation

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Xiao-Xi Guo

2012-11-01

Full Text Available Ginsenoside Rh2 (G-Rh2 has been shown to induce apoptotic cell death in a variety of cancer cells. However, the details of the signal transduction cascade involved in G-Rh2-induced cell death is unclear. In this manuscript we elucidate the molecular mechanism of G-Rh2-induced apoptosis in human hepatoma SK-HEP-1 cells by demonstrating that G-Rh2 causes rapid and dramatic translocation of both Bak and Bax, which subsequently triggers mitochondrial cytochrome c release and consequent caspase activation. Interestingly, siRNA-based gene inactivation of caspase-8 effectively delays caspase-9 activation and apoptosis induced by G-Rh2, indicating that caspase-8 also plays an important role in the G-Rh2-induced apoptosis program. Taken together, our results indicate that G-Rh2 employs a multi pro-apoptotic pathway to execute cancer cell death, suggesting a potential role for G-Rh2 as a powerful chemotherapeutic agent.

Bacterial Multidrug Efflux Pumps: Much More Than Antibiotic Resistance Determinants.

Science.gov (United States)

Blanco, Paula; Hernando-Amado, Sara; Reales-Calderon, Jose Antonio; Corona, Fernando; Lira, Felipe; Alcalde-Rico, Manuel; Bernardini, Alejandra; Sanchez, Maria Blanca; Martinez, Jose Luis

2016-02-16

Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics.

NDRG2 overexpression suppresses hepatoma cells survival during metabolic stress through disturbing the activation of fatty acid oxidation

International Nuclear Information System (INIS)

Pan, Tao; Zhang, Mei; Zhang, Fang; Yan, Guang; Ru, Yi; Wang, Qinhao; Zhang, Yao; Wei, Xuehui; Xu, Xinyuan; Shen, Lan; Zhang, Jian; Wu, Kaichun; Yao, Libo; Li, Xia

2017-01-01

Because of the high nutrient consumption and inadequate vascularization, solid tumor constantly undergoes metabolic stress during tumor development. Oncogenes and tumor suppressor genes participated in cancer cells' metabolic reprogramming. N-Myc downstream regulated gene 2 (NDRG2) is a recently identified tumor suppressor gene, but its function in cancer metabolism, particularly during metabolic stress, remains unclear. In this study, we found that NDRG2 overexpression significantly reduced hepatoma cell proliferation and enhanced cell apoptosis under glucose limitation. Moreover, NDRG2 overexpression aggravated energy imbalance and oxidative stress by decreasing the intracellular ATP and NADPH generation and increasing ROS levels. Strikingly, NDRG2 inhibited the activation of fatty acid oxidation (FAO), which preserves ATP and NADPH purveyance in the absence of glucose. Finally, mechanistic investigation showed that NDRG2 overexpression suppressed the glucose-deprivation induced AMPK/ACC pathway activation in hepatoma cells, whereas the expression of a constitutively active form of AMPK abrogated glucose-deprivation induced AMPK activation and cell apoptosis. Thus, as a negative regulator of AMPK, NDRG2 disturbs the induction of FAO genes by glucose limitation, leading to dysregulation of ATP and NADPH, and thus reduces the tolerance of hepatoma cells to glucose limitation. - Highlights: • NDRG2 overexpression reduces the tolerance of hepatoma cells to glucose limitation. • NDRG2 overexpression aggravates energy imbalance and oxidative stress under glucose deprivation. • NDRG2 overexpression disturbs the activation of FAO in hepatoma cells under glucose limitation. • NDRG2 overexpression inhibits the activation of AMPK/ACC pathway in hepatoma cells during glucose starvation.

Expression of multidrug resistance proteins in retinoblastoma

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Swati Shukla

2017-11-01

Full Text Available AIM: To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance. METHODS: Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy (PCNC were also prepared. Their chemosensitivity to chemotherapeutic agents (vincristine, etoposide and carboplatin were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells. RESULTS: Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein (P-gp was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1 (Mrp-1 expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associated protein (Lrp was observed in the drug resistant Y79 cells as well as in PCNC. CONCLUSION: Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy.

Expression of multidrug resistance proteins in retinoblastoma.

Science.gov (United States)

Shukla, Swati; Srivastava, Arpna; Kumar, Sunil; Singh, Usha; Goswami, Sandeep; Chawla, Bhavna; Bajaj, Mandeep Singh; Kashyap, Seema; Kaur, Jasbir

2017-01-01

To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance. Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy (PCNC) were also prepared. Their chemosensitivity to chemotherapeutic agents (vincristine, etoposide and carboplatin) were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells. Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein (P-gp) was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1 (Mrp-1) expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associated protein (Lrp) was observed in the drug resistant Y79 cells as well as in PCNC. Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy.

Expression of multidrug resistance proteins in retinoblastoma

Science.gov (United States)

Shukla, Swati; Srivastava, Arpna; Kumar, Sunil; Singh, Usha; Goswami, Sandeep; Chawla, Bhavna; Bajaj, Mandeep Singh; Kashyap, Seema; Kaur, Jasbir

2017-01-01

AIM To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance. METHODS Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy (PCNC) were also prepared. Their chemosensitivity to chemotherapeutic agents (vincristine, etoposide and carboplatin) were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells. RESULTS Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein (P-gp) was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1 (Mrp-1) expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associated protein (Lrp) was observed in the drug resistant Y79 cells as well as in PCNC. CONCLUSION Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy. PMID:29181307

Glucocorticoid-regulated and constitutive trafficking of proteolytically processed cell surface-associated glycoproteins in wild type and variant rat hepatoma cells

International Nuclear Information System (INIS)

Amacher, S.L.; Goodman, L.J.; Bravo, D.A.; Wong, K.Y.; Goldfine, I.D.; Hawley, D.M.; Firestone, G.L.

1989-01-01

Glucocorticoids regulate the trafficking of mouse mammary tumor virus (MMTV) glycoproteins to the cell surface in the rat hepatoma cell line M1.54, but not in the immunoselected sorting variant CR4. To compare the localization of MMTV glycoproteins to another proteolytically processed glycoprotein, both wild type M1.54 cells and variant CR4 cells were transfected with a human insulin receptor (hIR) expression vector, pRSVhIR. The production of cell surface hIR was monitored in dexamethasone-treated and -untreated wild type M1.54 and variant CR4 cells by indirect immunofluorescence, direct plasma membrane immunoprecipitation, and by [125I] insulin binding. In both wild type and variant rat hepatoma cells, hIR were localized at the cell surface in the presence or in the absence of 1 microM dexamethasone. In contrast, the glucocorticoid-regulated trafficking of cell surface MMTV glycoproteins occurred only in wild type M1.54 cells. We conclude that the hIR, which undergoes posttranslational processing reactions similar to MMTV glycoproteins, does not require glucocorticoids to be transported to the plasma membrane and is representative of a subset of cell surface glycoproteins whose trafficking is constitutive in rat hepatoma cells. Thus, MMTV glycoproteins and hIR provide specific cell surface markers to characterize the glucocorticoid-regulated and constitutive sorting pathways

Cell death induced by Morarah and Khaltita in hepatoma cancer cells (Huh-7).

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Baig, Saeeda; Alamgir, Mohiuddin

2009-10-01

To compare the combined and isolated growth inhibitory effects of Morarah and Khaltita (herbs) on hepatoma cell lines (Huh-7), through induction of apoptosis or necrosis. Comparative controlled in-vitro study. The Molecular Biology Laboratory, The Aga Khan University, Karachi, from June to December 2006. The growth of hepatoma cell lines (Huh-7) was checked by adding Khaltita and Morarah to the cells before culture in a 24 well plate. Six wells were selected and labeled for each of the four variables (controls, Khaltita, Morarah and mixture). After 2 days, cells were studied under an inverted phase contrast microscope and fields were recorded. Approximately four fields per slide of higher intensity were selected randomly to determine the dead cell density, and the procedure was repeated 10 or more times. Frequency and percentages were calculated for dead or alive cells in controls, Morarah, Khaltita and their mixture. Chi-square was used to compare the qualitative variables. P-values < 0.05 were considered significant. Morarah and Khaltita were found to induce statistically significant (p < 0.001) cell death in hepatoma cell lines (Huh-7). At a magnification of 40x, the controls showed 1% dead cells compared to 91% in Morarah, 83% in Khaltita and 73% in combined mixture of Khaltita and Morarah. At magnification of 20x, the controls showed 4% dead cells compared to 44% in Morarah, 47% in Khaltita and 49% in the combined mixture of Khaltita and Morarah. Morarah and Khaltita induced cell death in cultured hepatoma cells (Huh-7).

Hepatitis C virus E2 protein promotes human hepatoma cell proliferation through the MAPK/ERK signaling pathway via cellular receptors

International Nuclear Information System (INIS)

Zhao Lanjuan; Wang Lu; Ren Hao; Cao Jie; Li Li; Ke Jinshan; Qi Zhongtian

2005-01-01

Dysregulation of mitogen-activated protein kinase (MAPK) signaling pathways by various viruses has been shown to be responsible for viral pathogenicity. The molecular mechanism by which hepatitis C virus (HCV) infection caused human liver diseases has been investigated on the basis of abnormal intracellular signal events. Current data are very limited involved in transmembrane signal transduction triggered by HCV E2 protein. Here we explored regulation of the MAPK/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway by E2 expressed in Chinese hamster oval cells. In human hepatoma Huh-7 cells, E2 specifically activated the MAPK/ERK pathway including downstream transcription factor ATF-2 and greatly promoted cell proliferation. CD81 and low density lipoprotein receptor (LDLR) on the cell surface mediated binding of E2 to Huh-7 cells. The MAPK/ERK activation and cell proliferation driven by E2 were suppressed by blockage of CD81 as well as LDLR. Furthermore, pretreatment with an upstream kinase MEK1/2 inhibitor U0126 also impaired the MAPK/ERK activation and cell proliferation induced by E2. Our results suggest that the MAPK/ERK signaling pathway triggered by HCV E2 via its receptors maintains survival and growth of target cells

Multidrug Resistance Protein-4 Influences Aspirin Toxicity in Human Cell Line

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Isabella Massimi

2015-01-01

Full Text Available Overexpression of efflux transporters, in human cells, is a mechanism of resistance to drug and also to chemotherapy. We found that multidrug resistance protein-4 (MRP4 overexpression has a role in reducing aspirin action in patients after bypass surgery and, very recently, we found that aspirin enhances platelet MRP4 levels through peroxisome proliferator activated receptor-α (PPARα. In the present paper, we verified whether exposure of human embryonic kidney-293 cells (Hek-293 to aspirin modifies MRP4 gene expression and its correlation with drug elimination and cell toxicity. We first investigated the effect of high-dose aspirin in Hek-293 and we showed that aspirin is able to increase cell toxicity dose-dependently. Furthermore, aspirin effects, induced at low dose, already enhance MRP4 gene expression. Based on these findings, we compared cell viability in Hek-293, after high-dose aspirin treatment, in MRP4 overexpressing cells, either after aspirin pretreatment or in MRP4 transfected cells; in both cases, a decrease of selective aspirin cell growth inhibition was observed, in comparison with the control cultures. Altogether, these data suggest that exposing cells to low nontoxic aspirin dosages can induce gene expression alterations that may lead to the efflux transporter protein overexpression, thus increasing cellular detoxification of aspirin.

Emergence and spread of a human-transmissible multidrug-resistant nontuberculous mycobacterium

DEFF Research Database (Denmark)

Bryant, Josephine M; Grogono, Dorothy M; Rodriguez-Rincon, Daniela

2016-01-01

Lung infections with Mycobacterium abscessus, a species of multidrug-resistant nontuberculous mycobacteria, are emerging as an important global threat to individuals with cystic fibrosis (CF), in whom M. abscessus accelerates inflammatory lung damage, leading to increased morbidity and mortality....

Camel Milk Triggers Apoptotic Signaling Pathways in Human Hepatoma HepG2 and Breast Cancer MCF7 Cell Lines through Transcriptional Mechanism

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Hesham M. Korashy

2012-01-01

Full Text Available Few published studies have reported the use of crude camel milk in the treatment of stomach infections, tuberculosis and cancer. Yet, little research was conducted on the effect of camel milk on the apoptosis and oxidative stress associated with human cancer. The present study investigated the effect and the underlying mechanisms of camel milk on the proliferation of human cancer cells using an in vitro model of human hepatoma (HepG2 and human breast (MCF7 cancer cells. Our results showed that camel milk, but not bovine milk, significantly inhibited HepG2 and MCF7 cells proliferation through the activation of caspase-3 mRNA and activity levels, and the induction of death receptors in both cell lines. In addition, Camel milk enhanced the expression of oxidative stress markers, heme oxygenase-1 and reactive oxygen species production in both cells. Mechanistically, the increase in caspase-3 mRNA levels by camel milk was completely blocked by the transcriptional inhibitor, actinomycin D; implying that camel milk increased de novo RNA synthesis. Furthermore, Inhibition of the mitogen activated protein kinases differentially modulated the camel milk-induced caspase-3 mRNA levels. Taken together, camel milk inhibited HepG2 and MCF7 cells survival and proliferation through the activation of both the extrinsic and intrinsic apoptotic pathways.

Size-mediated cytotoxicity of nanocrystalline titanium dioxide, pure and zinc-doped hydroxyapatite nanoparticles in human hepatoma cells

International Nuclear Information System (INIS)

Devanand Venkatasubbu, G.; Ramasamy, S.; Avadhani, G. S.; Palanikumar, L.; Kumar, J.

2012-01-01

Nanoparticles are highly used in biological applications including nanomedicine. In this present study, the interaction of HepG2 hepatocellular carcinoma cells (HCC) with hydroxyapatite (HAp), zinc-doped hydroxyapatite, and titanium dioxide (TiO 2 ) nanoparticles were investigated. Hydroxyapatite, zinc-doped hydroxyapatite and titanium dioxide nanoparticles were prepared by wet precipitation method. They were subjected to isochronal annealing at different temperatures. Particle morphology and size distribution were characterized by X-ray diffraction and transmission electron microscope. The nanoparticles were co-cultured with HepG2 cells. MTT assay was employed to evaluate the proliferation of tumor cells. The DNA damaging effect of HAp, Zn-doped HAp, and TiO 2 nanoparticles in human hepatoma cells (HepG2) were evaluated using DNA fragmentation studies. The results showed that in HepG2 cells, the anti-tumor activity strongly depend on the size of nanoparticles in HCC cells. Cell cycle arrest analysis for HAp, zinc-doped HAp, and TiO 2 nanoparticles revealed the influence of HAp, zinc-doped HAp, and titanium dioxide nanoparticles on the apoptosis of HepG2 cells. The results imply that the novel nano nature effect plays an important role in the biomedicinal application of nanoparticles.

Small-molecule synthetic compound norcantharidin reverses multi-drug resistance by regulating Sonic hedgehog signaling in human breast cancer cells.

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Yu-Jen Chen

Full Text Available Multi-drug resistance (MDR, an unfavorable factor compromising treatment efficacy of anticancer drugs, involves upregulated ATP binding cassette (ABC transporters and activated Sonic hedgehog (Shh signaling. By preparing human breast cancer MCF-7 cells resistant to doxorubicin (DOX, we examined the effect and mechanism of norcantharidin (NCTD, a small-molecule synthetic compound, on reversing multidrug resistance. The DOX-prepared MCF-7R cells also possessed resistance to vinorelbine, characteristic of MDR. At suboptimal concentration, NCTD significantly inhibited the viability of DOX-sensitive (MCF-7S and DOX-resistant (MCF-7R cells and reversed the resistance to DOX and vinorelbine. NCTD increased the intracellular accumulation of DOX in MCF-7R cells and suppressed the upregulated the mdr-1 mRNA, P-gp and BCRP protein expression, but not the MRP-1. The role of P-gp was strengthened by partial reversal of the DOX and vinorelbine resistance by cyclosporine A. NCTD treatment suppressed the upregulation of Shh expression and nuclear translocation of Gli-1, a hallmark of Shh signaling activation in the resistant clone. Furthermore, the Shh ligand upregulated the expression of P-gp and attenuated the growth inhibitory effect of NCTD. The knockdown of mdr-1 mRNA had not altered the expression of Shh and Smoothened in both MCF-7S and MCF-7R cells. This indicates that the role of Shh signaling in MDR might be upstream to mdr-1/P-gp, and similar effect was shown in breast cancer MDA-MB-231 and BT-474 cells. This study demonstrated that NCTD may overcome multidrug resistance through inhibiting Shh signaling and expression of its downstream mdr-1/P-gp expression in human breast cancer cells.

Co-operation of the transcription factor hepatocyte nuclear factor-4 with Sp1 or Sp3 leads to transcriptional activation of the human haem oxygenase-1 gene promoter in a hepatoma cell line.

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Takahashi, Shigeru; Matsuura, Naomi; Kurokawa, Takako; Takahashi, Yuji; Miura, Takashi

2002-11-01

We reported previously that the 5'-flanking region (nucleotides -1976 to -1655) of the human haem oxygenase-1 ( hHO-1 ) gene enhances hHO-1 promoter activity in human hepatoma HepG2 cells, but not in HeLa cells [Takahashi, Takahashi, Ito, Nagano, Shibahara and Miura (1999) Biochim. Biophys. Acta 1447, 231-235]. To define more precisely the regulatory elements involved, in the present study we have functionally dissected this region and localized the enhancer to a 50 bp fragment (-1793 to -1744). Site-direct mutagenesis analysis revealed that two regions were responsible for this enhancer activity, i.e. a hepatocyte nuclear factor-4 (HNF-4) homologous region and a GC box motif homologous region. Mutation in either region alone moderately decreased enhancer activity. However, mutations in both regions reduced promoter activity to the basal level. Electrophoretic mobility-shift assays demonstrated that the P5-2 fragment (-1793 to -1744) interacted with at least two nuclear factors, i.e. HNF-4 and Sp1/Sp3. Co-transfection experiments using Drosophila SL2 cells revealed that HNF-4 and Sp1/Sp3 synergistically stimulated the enhancer activity of the P5-2 fragment. These results indicate that co-operation of HNF-4 with Sp1 or Sp3 leads to the activation of hHO-1 gene expression in hepatoma cells.

Dosimetric considerations in radioimmunotherapy of patients with hepatoma

International Nuclear Information System (INIS)

Leichner, P.K.; Klein, J.L.; Order, S.E.

1986-01-01

Dosimetric studies of I-131 labeled antiferritin have provided the foundation for preparative and administrative aspects of radiolabeled antibody treatment of patients with hepatoma. Tumor response to I-131 labeled antiferritin IgG was encouraging and radioimmunotherapy with Y-90 labeled antiferritin IgG was recently initiated. For these patients, In-111 labeled antiferritin IgG was used as the imaging agent, with administered activities ranging from 0.8 - 7 mCi. Serial gamma camera imaging from 30 minutes to 6 days post injection demonstrated that 5-30% of the administered activity localized in hepatomas (8/12 patients). The mean value of the effective half-life in the tumor and liver was 2.8 d. Disappearance curves for the blood circulation, spleen, and other normal tissues were biphasic such that 50% of the activity disappeared within 24 hours post injection. The eight patients who demonstrated sufficient tumor localization where subsequently treated with Y-90 labeled antiferritin IgG. Administered activities were dependent on tumor volume and uptake of radiolabeled IgG and ranged from 8 - 20 mCi. The remaining patients were treated under other existing protocols. 10 references

Comparison of the multi-drug resistant human hepatocellular carcinoma cell line Bel-7402/ADM model established by three methods

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Zhong Xingguo

2010-08-01

Full Text Available Abstract Background To compare the biological characteristics of three types of human hepatocellular carcinoma multi-drug resistant cell sub-lines Bel-7402/ADM models established by three methods. Methods Established human hepatocellular carcinoma adriamycin (ADM multi-drug resistant cell sub-lines models Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS by three methods of in vitro concentration gradient increased induction, nude mice liver-implanted induction and subcutaneous-implanted induction respectively. Phase contrast microscopy was used to observe the cells and the MTT (methyl thiazolyl tetrazolium method was used to detect drug resistance of the three different sub-lines of cells. Results The three groups of drug resistant cells, Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS generated cross-resistance to ADM and CDDP (cis-Diaminedichloroplatinum, but showed a significant difference in resistance to Bel-7402 IC50 value (P V, 46 h (Bel-7402/ADML, and 45 h (Bel-7402/ADMS. The excretion rates of ADM were significantly increased compared with the parent cell (34.14% line and were 81.06% (Bel-7402/ADMV, 66.56% (Bel-7402/ADML and 61.56% (Bel-7402/ADMS. Expression of P-gp and MRP in the three groups of resistant cells was significantly enhanced (P P > 0.05. Conclusions Stable resistance was involved in the resistant cell line model established by the above three methods. Liver implantation was a good simulation of human hepatocellular and proved to be an ideal model with characteristics similar to human hepatocellular biology and the pharmacokinetics of anticancer drugs.

Degradation and repair of DNA from rat hepatoma cells after treatments with γ-rays and N-methyl-N-nitrosourea

International Nuclear Information System (INIS)

Zakrzhevskaya, D.G.; Kulagina, T.P.; Petrov, S.I.; Fomenko, L.A.; Gaziev, A.I.

1977-01-01

It has been shown, that DNA single-strand breaks induced in the cells of ascite hepatoma with γ-rays and metylnitrosourea (MNM) are effectively repaired. DNA two-strand breaks of hepatoma cells, treated with MNM are effectively repaired in situ as well. Only insignificant part of two-strand gamma-induced breaks in DNA of these cells is repaired during postirradiation period. Under combined effect of gamma rays and MNM on hepatoma cells a delay of DNA reparation and its further degradation as well as inhibition of nonplanned DNA synthesis and the suppression of DNA-polymerase 1 activity are observed

Salinomycin overcomes ABC transporter-mediated multidrug and apoptosis resistance in human leukemia stem cell-like KG-1a cells

International Nuclear Information System (INIS)

Fuchs, Dominik; Daniel, Volker; Sadeghi, Mahmoud; Opelz, Gerhard; Naujokat, Cord

2010-01-01

Leukemia stem cells are known to exhibit multidrug resistance by expression of ATP-binding cassette (ABC) transporters which constitute transmembrane proteins capable of exporting a wide variety of chemotherapeutic drugs from the cytosol. We show here that human promyeloblastic leukemia KG-1a cells exposed to the histone deacetylase inhibitor phenylbutyrate resemble many characteristics of leukemia stem cells, including expression of functional ABC transporters such as P-glycoprotein, BCRP and MRP8. Consequently, KG-1a cells display resistance to the induction of apoptosis by various chemotherapeutic drugs. Resistance to apoptosis induction by chemotherapeutic drugs can be reversed by cyclosporine A, which effectively inhibits the activity of P-glycoprotein and BCRP, thus demonstrating ABC transporter-mediated drug resistance in KG-1a cells. However, KG-1a are highly sensitive to apoptosis induction by salinomycin, a polyether ionophore antibiotic that has recently been shown to kill human breast cancer stem cell-like cells and to induce apoptosis in human cancer cells displaying multiple mechanisms of drug and apoptosis resistance. Whereas KG-1a cells can be adapted to proliferate in the presence of apoptosis-inducing concentrations of bortezomib and doxorubicin, salinomycin does not permit long-term adaptation of the cells to apoptosis-inducing concentrations. Thus, salinomycin should be regarded as a novel and effective agent for the elimination of leukemia stem cells and other tumor cells exhibiting ABC transporter-mediated multidrug resistance.

The hyper-radiosensitivity effect of human hepatoma SMMC-7721 cells exposed to low dose γ-rays and 12C ions

International Nuclear Information System (INIS)

Jin Xiaodong; Li Qiang; Li Wenjian; Wang Jufang; Guo Chuanling; Hao Jifang

2006-01-01

Hypersensitive response of mammalian cells in cell killing to X- and γ-rays has been reported at doses below 1 Gy. The purpose of this study was to examine the low dose sensitivity of human hepatoma SMMC-7721 cells irradiated with 6 Co γ-rays and 50 MeV/u 12 C ions. Experiments using γ-rays and charged particle irradiation were performed, particularly in the low dose range from 0 to 2 Gy. The survival effect of SMMC-7721 cells was measured by means of standard clonogenic assay in conjunction with a cell sorter. The result indicates SMMC-7721 cells showed hyper-radiosensitive response at low doses and increased radio-resistance at larger single doses for the carbon ions (LET = 45.2 keV/μm) and the γ-rays. However, the HRS/IRR effect caused by high-LET irradiation is different from that by low-LET radiation. This might possibly be due to the difference in the mode of energy deposition by particle beam and low-LET irradiation

A study on the thermochemotherapy effect of nanosized As2O3/MZF thermosensitive magnetoliposomes on experimental hepatoma in vitro and in vivo

Science.gov (United States)

Wang, Li; Zhang, Jia; An, Yanli; Wang, Ziyu; Liu, Jing; Li, Yutao; Zhang, Dongsheng

2011-08-01

In this paper, we describe the synthesis and characterization of a nanosized, thermosensitive magnetoliposome encapsulating magnetic nanoparticles (MZFs) and antitumor drugs (As2O3). The nanoliposomes were spherical and mostly single volume, with an average diameter of 128.2 nm. Differential scanning calorimetry (DSC) showed a liposome phase transition temperature of 42.71 °C. After that, we studied the liposomes' anti-hepatoma effect in vitro and in vivo. The antitumor effect of the nanoliposomes on human hepatoma cells, SMMC-7721, and changes in expression of apoptosis-related proteins were examined in vitro. The results show that As2O3/MZF thermosensitive magnetoliposomes combined with hyperthermia had a great impact on the Bax/Bcl-2 ratio, which increased to 1.914 and exhibited a rapid response to induce apoptosis of tumor cells. An in situ rabbit liver tumor model was established and used to evaluate the antitumor effect of combined hyperthermia and chemotherapy following transcatheter arterial embolization with As2O3/MZF thermosensitive magnetoliposomes. The results demonstrated a strong anti-hepatoma effect, with a tumor volume inhibition rate of up to 85.22%. Thus, As2O3/MZF thermosensitive magnetoliposomes may play a great role in the treatment of hepatocarcinoma.

Total Saponin from Root of Actinidia valvata Dunn Inhibits Hepatoma 22 Growth and Metastasis In Vivo by Suppression Angiogenesis

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Guo-Yin Zheng

2012-01-01

Full Text Available The root of Actinidia valvata dunn has been widely used in the treatment of hepatocellular carcinoma (HCC, proved to be beneficial for a longer and better life in China. In present work, total saponin from root of Actinidia valvata Dunn (TSAVD was extracted, and its effects on hepatoma H22-based mouse in vivo were observed. Primarily transplanted hypodermal hepatoma H22-based mice were used to observe TSAVD effect on tumor growth. The microvessel density (MVD, vascular endothelial growth factor (VEGF, basic fibroblast growth factor (bFGF are characterized factors of angiogenesis, which were compared between TSAVD-treated and control groups. Antimetastasis effect on experimental pulmonary metastasis hepatoma mice was also observed in the study. The results demonstrated that TSAVD can effectively inhibit HCC growth and metastasis in vivo, inhibit the formation of microvessel, downregulate expressions of VEGF and bFGF, and retrain angiogenesis of hepatoma 22 which could be one of the reasons.

Anti-hepatoma activity of a novel compound glaucocalyxin H in vivo and in vitro.

Science.gov (United States)

Hai, Guangfan; Zhang, Chong; Jia, Yanlong; Bai, Suping; Han, Jinfen; Guo, Lanqing; Cui, Taizhen; Niu, Bingxuan; Huang, Feng; Song, Yu

2015-06-01

Glaucocalyxin H (GLH) is a new compound isolated from a traditional Chinese medical herb Isodon japonica var. glaucocalyx which has been used for folk medicine. This study was carried out for the first time to investigate the potential role of GLH in anti-hepatoma activity and underlying mechanisms in it. GLH could inhibit the growth of tumor in mice and induce HepG2 cells to death as assessed by the tumor reduction assay, toxic assay, morphological change, and survival rate assay. Many antitumor drugs originated from plants could inhibit the growth of tumor by inducing cells to apoptosis. The morphological changes of HepG2 cells treated with different concentrations of GLH under fluorescence and electron microscope and apoptotic rates were detected to verify its effect on apoptosis. As shown in the study, GLH could induce HepG2 cells to apoptosis in a dose-dependent manner. Bcl2 and Bax proteins played important roles in apoptosis and the disequilibrium between Bcl2 and Bax might result in apoptosis. The expression of Bax protein was upregulated and Bcl2 protein was downregulated in HepG2 cells treated with GLH assessed by Western blotting, and they were in a dose-dependent manner. Taken together, GLH can inhibit the growth of hepatoma cells in vivo and in vitro by inducing cell apoptosis due to the decreased Bcl2 and increased Bax proteins suggesting that GLH could be a potential candidate as an anti-hepatoma agent for the therapeutic treatment of hepatoma.

Coating independent cytotoxicity of citrate- and PEG-coated silver nanoparticles on a human hepatoma cell line.

Science.gov (United States)

Bastos, Verónica; Ferreira-de-Oliveira, José M P; Carrola, Joana; Daniel-da-Silva, Ana L; Duarte, Iola F; Santos, Conceição; Oliveira, Helena

2017-01-01

The antibacterial potential of silver nanoparticles (AgNPs) resulted in their increasing incorporation into consumer, industrial and biomedical products. Therefore, human and environmental exposure to AgNPs (either as an engineered product or a contaminant) supports the emergent research on the features conferring them different toxicity profiles. In this study, 30nm AgNPs coated with citrate or poly(ethylene glycol) (PEG) were used to assess the influence of coating on the effects produced on a human hepatoma cell line (HepG2), namely in terms of viability, apoptosis, apoptotic related genes, cell cycle and cyclins gene expression. Both types of coated AgNPs decreased cell proliferation and viability with a similar toxicity profile. At the concentrations used (11 and 5μg/mL corresponding to IC50 and ~IC10 levels, respectively) the amount of cells undergoing apoptosis was not significant and the apoptotic related genes BCL2 (anti-apoptotic gene) and BAX (pro-apoptotic gene) were both downregulated. Moreover, both AgNPs affected HepG2 cell cycle progression at the higher concentration (11μg/mL) by increasing the percentage of cells in S (synthesis phase) and G2 (Gap 2 phase) phases. Considering the cell-cycle related genes, the expression of cyclin B1 and cyclin E1 genes were decreased. Thus, this work has shown that citrate- and PEG-coated AgNPs impact on HepG2 apoptotic gene expression, cell cycle dynamics and cyclin regulation in a similar way. More research is needed to determine the properties that confer AgNPs at lower toxicity, since their use has proved helpful in several industrial and biomedical contexts. Copyright © 2016. Published by Elsevier B.V.

Role of ROS-mediated autophagy in radiation-induced bystander effect of hepatoma cells.

Science.gov (United States)

Wang, Xiangdong; Zhang, Jianghong; Fu, Jiamei; Wang, Juan; Ye, Shuang; Liu, Weili; Shao, Chunlin

2015-05-01

Autophagy plays a crucial role in cellular response to ionizing radiation, but it is unclear whether autophagy can modulate radiation-induced bystander effect (RIBE). Here, we investigated the relationship between bystander damage and autophagy in human hepatoma cells of HepG2. HepG2 cells were treated with conditioned medium (CM) collected from 3 Gy γ-rays irradiated hepatoma HepG2 cells for 4, 12, or 24 h, followed by the measurement of micronuclei (MN), intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and protein expressions of microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 in the bystander HepG2 cells. In some experiments, the bystander HepG2 cells were respectively transfected with LC3 small interfering RNA (siRNA), Beclin-1 siRNA or treated with 1% dimethyl sulfoxide (DMSO). Additional MN and mitochondrial dysfunction coupled with ROS were induced in the bystander cells. The expressions of protein markers of autophagy, LC3-II/LC3-I and Beclin-1, increased in the bystander cells. The inductions of bystander MN and overexpressions of LC3 and Beclin-1 were significantly diminished by DMSO. However, when the bystander cells were transfected with LC3 siRNA or Beclin-1 siRNA, the yield of bystander MN was significantly enhanced. The elevated ROS have bi-functions in balancing the bystander effects. One is to cause MN and the other is to induce protective autophagy.

Celastraceae sesquiterpenes as a new class of modulators that bind specifically to human P-glycoprotein and reverse cellular multidrug resistance.

Science.gov (United States)

Muñoz-Martínez, Francisco; Lu, Peihua; Cortés-Selva, Fernando; Pérez-Victoria, José María; Jiménez, Ignacio A; Ravelo, Angel G; Sharom, Frances J; Gamarro, Francisco; Castanys, Santiago

2004-10-01

Overexpression of ABCB1 (MDR1) P-glycoprotein, a multidrug efflux pump, is one mechanism by which tumor cells may develop multidrug resistance (MDR), preventing the successful chemotherapeutic treatment of cancer. Sesquiterpenes from Celastraceae family are natural compounds shown previously to reverse MDR in several human cancer cell lines and Leishmania strains. However, their molecular mechanism of reversion has not been characterized. In the present work, we have studied the ability of 28 dihydro-beta-agarofuran sesquiterpenes to reverse the P-glycoprotein-dependent MDR phenotype and elucidated their molecular mechanism of action. Cytotoxicity assays using human MDR1-transfected NIH-3T3 cells allowed us to select the most potent sesquiterpenes reversing the in vitro resistance to daunomycin and vinblastine. Flow cytometry experiments showed that the above active compounds specifically inhibited drug transport activity of P-glycoprotein in a saturable, concentration-dependent manner (K(i) down to 0.24 +/- 0.01 micromol/L) but not that of ABCC1 (multidrug resistance protein 1; MRP1), ABCC2 (MRP2), and ABCG2 (breast cancer resistance protein; BCRP) transporters. Moreover, sesquiterpenes inhibited at submicromolar concentrations the P-glycoprotein-mediated transport of [(3)H]colchicine and tetramethylrosamine in plasma membrane from CH(R)B30 cells and P-glycoprotein-enriched proteoliposomes, supporting that P-glycoprotein is their molecular target. Photoaffinity labeling in plasma membrane and fluorescence spectroscopy experiments with purified protein suggested that sesquiterpenes interact with transmembrane domains of P-glycoprotein. Finally, sesquiterpenes modulated P-glycoprotein ATPase-activity in a biphasic, concentration-dependent manner: they stimulated at very low concentrations but inhibited ATPase activity as noncompetitive inhibitors at higher concentrations. Sesquiterpenes from Celastraceae are promising P-glycoprotein modulators with potential

Curcumin promotes apoptosis in A549/DDP multidrug-resistant human lung adenocarcinoma cells through an miRNA signaling pathway

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Zhang, Jian, E-mail: zhangjian197011@yahoo.com [Department of Respiratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi' an 710032 (China); Zhang, Tao [Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, Xi' an 710038 (China); Ti, Xinyu; Shi, Jieran; Wu, Changgui; Ren, Xinling [Department of Respiratory Medicine, Xijing Hospital, The Fourth Military Medical University, Xi' an 710032 (China); Yin, Hong, E-mail: yinnhong@yahoo.com [The Medical Image Center, Xijing Hospital, The Fourth Military Medical University, Xi' an 710032 (China)

2010-08-13

Research highlights: {yields} Curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells {yields} Curcumin promotes apoptosis in A549/DDP cells through a miRNA signaling pathway {yields} Curcumin induces A549/DDP cell apoptosis by downregulating miR-186* {yields} miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin -- Abstract: Curcumin extracted from the rhizomes of Curcuma longa L. has been shown to have inhibitory effects on cancers through its anti-proliferative and pro-apoptotic activities. Emerging evidence demonstrates that curcumin can overcome drug resistance to classical chemotherapies. Thus, the mechanisms underlying the anti-tumor activities of curcumin require further study. In our study, we first demonstrated that curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells. Further studies showed that curcumin altered miRNA expression; in particular, significantly downregulated the expression of miR-186* in A549/DDP. In addition, transfection of cells with a miR-186* inhibitor promoted A549/DDP apoptosis, and overexpression of miR-186* significantly inhibited curcumin-induced apoptosis in A549/DDP cells. These observations suggest that miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin.

Curcumin promotes apoptosis in A549/DDP multidrug-resistant human lung adenocarcinoma cells through an miRNA signaling pathway

International Nuclear Information System (INIS)

Zhang, Jian; Zhang, Tao; Ti, Xinyu; Shi, Jieran; Wu, Changgui; Ren, Xinling; Yin, Hong

2010-01-01

Research highlights: → Curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells → Curcumin promotes apoptosis in A549/DDP cells through a miRNA signaling pathway → Curcumin induces A549/DDP cell apoptosis by downregulating miR-186* → miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin -- Abstract: Curcumin extracted from the rhizomes of Curcuma longa L. has been shown to have inhibitory effects on cancers through its anti-proliferative and pro-apoptotic activities. Emerging evidence demonstrates that curcumin can overcome drug resistance to classical chemotherapies. Thus, the mechanisms underlying the anti-tumor activities of curcumin require further study. In our study, we first demonstrated that curcumin had anti-cancer effects on A549/DDP multidrug-resistant human lung adenocarcinoma cells. Further studies showed that curcumin altered miRNA expression; in particular, significantly downregulated the expression of miR-186* in A549/DDP. In addition, transfection of cells with a miR-186* inhibitor promoted A549/DDP apoptosis, and overexpression of miR-186* significantly inhibited curcumin-induced apoptosis in A549/DDP cells. These observations suggest that miR-186* may serve as a potential gene therapy target for refractory lung cancer that is sensitive to curcumin.

Elimination of Cancer Stem-Like “Side Population” Cells in Hepatoma Cell Lines by Chinese Herbal Mixture “Tien-Hsien Liquid”

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Chih-Jung Yao

2012-01-01

Full Text Available There are increasing pieces of evidence suggesting that the recurrence of cancer may result from a small subpopulation of cancer stem cells, which are resistant to the conventional chemotherapy and radiotherapy. We investigated the effects of Chinese herbal mixture Tien-Hsien Liquid (THL on the cancer stem-like side population (SP cells isolated from human hepatoma cells. After sorting and subsequent culture, the SP cells from Huh7 hepatoma cells appear to have higher clonogenicity and mRNA expressions of stemness genes such as SMO, ABCG2, CD133, β-catenin, and Oct-4 than those of non-SP cells. At dose of 2 mg/mL, THL reduced the proportion of SP cells in HepG2, Hep3B, and Huh7 cells from 1.33% to 0.49%, 1.55% to 0.43%, and 1.69% to 0.27%, respectively. The viability and colony formation of Huh7 SP cells were effectively suppressed by THL dose-dependently, accompanied with the inhibition of stemness genes, e.g., ABCG2, CD133, and SMO. The tumorigenicity of THL-treated Huh7 SP cells in NOD/SCID mice was also diminished. Moreover, combination with THL could synergize the effect of doxorubicin against Huh7 SP cells. Our data indicate that THL may act as a cancer stem cell targeting therapeutics and be regarded as complementary and integrative medicine in the treatment of hepatoma.

Effects of PARP-1 inhibitors AG-014699 and AZD2281 on proliferation and apoptosis of human hepatoma cell line HepG2

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DU Senrong

2015-06-01

Full Text Available ObjectiveTo observe the inhibitory and pro-apoptotic effects of two poly(ADP-ribose polymerase (PARP-1 inhibitors, AG-014699 and AZD2281, on human hepatoma HepG2 cells and preliminarily explore the mechanism by which AG-014699 induces HepG2 cell apoptosis, and to provide a new therapeutic target for hepatoma. MethodsThe effects of different concentrations of AG-014699 and AZD2281 on HepG2 cell proliferation were determined by MTT assay. The cell apoptosis rate was measured by flow cytometry. The expression levels of caspase-3 and caspase-8 were measured by Western Blot. Inter-group comparison was made by t test. ResultsBoth AG-014699 and AZD2281 suppressed HepG2 cell proliferation in a time- and dose-dependent manner. However, the sensitivity of HepG2 cells to the two PARP-1 inhibitors was different. The half-maximal inhibitory concentrations of AG-014699 and AZD2281 at 48 h determined by MTT assay were about 20 μmol/L and 400 μmol/L, respectively. Flow cytometry and Western blot were not used to evaluate the apoptosis of HepG2 cells exposed to AZD2281 to which these cells were not sensitive. HepG2 cell apoptosis could be induced by 10, 30, and 50 μmol/L AG-014699, and the highest apoptosis rate at 48 h was significantly higher than that of the control group (3100%±2.13% vs 09%±0013%, P＜0.01. Compared with those in the control group, the protein levels of caspase-3 and caspase-8 in HepG2 cells after 48-h exposure to 30, and 50 μmol/L AG-014699 increased. ConclusionThe two PARP-1 inhibitors AG-014699 and AZD2281 can inhibit the proliferation of HepG2 cells, which showed different sensitivities to the two inhibitors. AG-014699 can induce HepG2 cell apoptosis by up-regulating the protein expression of caspase-3 and caspase-8.

Epithelial-Mesenchymal Transitions and the Expression of Twist in MCF-7/ADR,Human Multidrug-Resistant Breast Cancer Cells

Institute of Scientific and Technical Information of China (English)

Fei Zhang; Yurong Shi; Lin Zhang; Bin Zhang; Xiyin Wei; Yi Yang; RUi Wang; Ruifang Niu

2007-01-01

OBJECTIVE To study the expression levels of Twist and epithelialmesenchymal transitions in multidrug-resistant MCF-7/ADR breast cancer cells,and to study the relationship between multidrug resistance (MDR) and metastatic potential of the cells.METHODS RT-PCR,immunohislochemical and Western blotting methods were used to examine the changes of expression levels of the transcription factor Twist.E-cadherin and N-cadherin in the MCF-7 breast cancer cell line and its multidrug-resistant variant.MCF-7/ADR.RESULTS In MCF-7 cells,the expression of E-cadherin can be detected,but there is no expression of Twisl or N-cadherin.In MCF-7/ADR cells,E-cadherin expression is lost.bul the expression of two other genes was significantly positive.CONCLUSION Epithelial-mesenchymal transitions induced by Twist,may have a relationship with enhanced invasion and metastatic potential during the development of multidrug-resistant MCF-7/ADR breast cancer cells.

A study on the thermochemotherapy effect of nanosized As{sub 2}O{sub 3}/MZF thermosensitive magnetoliposomes on experimental hepatoma in vitro and in vivo

Energy Technology Data Exchange (ETDEWEB)

Wang Li; Zhang Jia; Wang Ziyu; Liu Jing; Li Yutao; Zhang Dongsheng [School of Medicine, Southeast University, NO. 87 Ding jia qiao, Nanjing 210009 (China); An Yanli, E-mail: wangli040418@163.com, E-mail: zdszds1222@163.com [Affiliated Zhong-Da Hospital of Southeast University, Nanjing 210009 (China)

2011-08-05

In this paper, we describe the synthesis and characterization of a nanosized, thermosensitive magnetoliposome encapsulating magnetic nanoparticles (MZFs) and antitumor drugs (As{sub 2}O{sub 3}). The nanoliposomes were spherical and mostly single volume, with an average diameter of 128.2 nm. Differential scanning calorimetry (DSC) showed a liposome phase transition temperature of 42.71 deg. C. After that, we studied the liposomes' anti-hepatoma effect in vitro and in vivo. The antitumor effect of the nanoliposomes on human hepatoma cells, SMMC-7721, and changes in expression of apoptosis-related proteins were examined in vitro. The results show that As{sub 2}O{sub 3}/MZF thermosensitive magnetoliposomes combined with hyperthermia had a great impact on the Bax/Bcl-2 ratio, which increased to 1.914 and exhibited a rapid response to induce apoptosis of tumor cells. An in situ rabbit liver tumor model was established and used to evaluate the antitumor effect of combined hyperthermia and chemotherapy following transcatheter arterial embolization with As{sub 2}O{sub 3}/MZF thermosensitive magnetoliposomes. The results demonstrated a strong anti-hepatoma effect, with a tumor volume inhibition rate of up to 85.22%. Thus, As{sub 2}O{sub 3}/MZF thermosensitive magnetoliposomes may play a great role in the treatment of hepatocarcinoma.

The reversal effects of 3-bromopyruvate on multidrug resistance in vitro and in vivo derived from human breast MCF-7/ADR cells.

Directory of Open Access Journals (Sweden)

Long Wu

Full Text Available P-glycoprotein mediated efflux is one of the main mechanisms for multidrug resistance in cancers, and 3-Bromopyruvate acts as a promising multidrug resistance reversal compound in our study. To test the ability of 3-Bromopyruvate to overcome P-glycoprotein-mediated multidrug resistance and to explore its mechanisms of multidrug resistance reversal in MCF-7/ADR cells, we evaluate the in vitro and in vivo modulatory activity of this compound.The in vitro and in vivo activity was determined using the MTT assay and human breast cancer xenograft models. The gene and protein expression of P-glycoprotein were determined using real-time polymerase chain reaction and the Western blotting technique, respectively. ABCB-1 bioactivity was tested by fluorescence microscopy, multi-mode microplate reader, and flow cytometry. The intracellular levels of ATP, HK-II, and ATPase activity were based on an assay kit according to the manufacturer's instructions.3-Bromopyruvate treatment led to marked decreases in the IC50 values of selected chemotherapeutic drugs [e.g., doxorubicin (283 folds, paclitaxel (85 folds, daunorubicin (201 folds, and epirubicin (171 folds] in MCF-7/ADR cells. 3-Bromopyruvate was found also to potentiate significantly the antitumor activity of epirubicin against MCF-7/ADR xenografts. The intracellular level of ATP decreased 44%, 46% in the presence of 12.5.25 µM 3-Bromopyruvate, whereas the accumulation of rhodamine 123 and epirubicin (two typical P-glycoprotein substrates in cells was significantly increased. Furthermore, we found that the mRNA and the total protein level of P-glycoprotein were slightly altered by 3-Bromopyruvate. Moreover, the ATPase activity was significantly inhibited when 3-Bromopyruvate was applied.We demonstrated that 3-Bromopyruvate can reverse P-glycoprotein-mediated efflux in MCF-7/ADR cells. Multidrug resistance reversal by 3-Bromopyruvate occurred through at least three approaches, namely, a decrease in the

The reversal effects of 3-bromopyruvate on multidrug resistance in vitro and in vivo derived from human breast MCF-7/ADR cells.

Science.gov (United States)

Wu, Long; Xu, Jun; Yuan, Weiqi; Wu, Baojian; Wang, Hao; Liu, Guangquan; Wang, Xiaoxiong; Du, Jun; Cai, Shaohui

2014-01-01

P-glycoprotein mediated efflux is one of the main mechanisms for multidrug resistance in cancers, and 3-Bromopyruvate acts as a promising multidrug resistance reversal compound in our study. To test the ability of 3-Bromopyruvate to overcome P-glycoprotein-mediated multidrug resistance and to explore its mechanisms of multidrug resistance reversal in MCF-7/ADR cells, we evaluate the in vitro and in vivo modulatory activity of this compound. The in vitro and in vivo activity was determined using the MTT assay and human breast cancer xenograft models. The gene and protein expression of P-glycoprotein were determined using real-time polymerase chain reaction and the Western blotting technique, respectively. ABCB-1 bioactivity was tested by fluorescence microscopy, multi-mode microplate reader, and flow cytometry. The intracellular levels of ATP, HK-II, and ATPase activity were based on an assay kit according to the manufacturer's instructions. 3-Bromopyruvate treatment led to marked decreases in the IC50 values of selected chemotherapeutic drugs [e.g., doxorubicin (283 folds), paclitaxel (85 folds), daunorubicin (201 folds), and epirubicin (171 folds)] in MCF-7/ADR cells. 3-Bromopyruvate was found also to potentiate significantly the antitumor activity of epirubicin against MCF-7/ADR xenografts. The intracellular level of ATP decreased 44%, 46% in the presence of 12.5.25 µM 3-Bromopyruvate, whereas the accumulation of rhodamine 123 and epirubicin (two typical P-glycoprotein substrates) in cells was significantly increased. Furthermore, we found that the mRNA and the total protein level of P-glycoprotein were slightly altered by 3-Bromopyruvate. Moreover, the ATPase activity was significantly inhibited when 3-Bromopyruvate was applied. We demonstrated that 3-Bromopyruvate can reverse P-glycoprotein-mediated efflux in MCF-7/ADR cells. Multidrug resistance reversal by 3-Bromopyruvate occurred through at least three approaches, namely, a decrease in the intracellular

The inhibition effect of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin-induced aryl hydrocarbon receptor activation in human hepatoma cells with the treatment of cadmium chloride

International Nuclear Information System (INIS)

Chao, How-Ran; Tsou, Tsui-Chun; Chen, Hung-Ta; Chang, Eddy Essen; Tsai, Feng-Yuan; Lin, Ding-Yan; Chen, Fu-An; Wang, Ya-Fen

2009-01-01

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), considered as endocrine disruptors, tend to accumulate in fatty tissues. Dioxin-responsive element chemical activated luciferase gene expression assay (DRE-luciferase assay) has been recognized as a semi-quantitative method for screening dioxins for its fast and low-cost as compared with HRGC/HRMS. However, some problems with the bioassay, including specificity, detection variation resulted from different cleanup strategies, and uncertainty of false-negative or false-positive results, remain to be overcome. Cadmium is a prevalent environmental contaminant around the world. This study was aimed to examine the effects of cadmium on the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced activation of aryl hydrocarbon receptor (AhR)-mediated gene expression in human hepatoma cells (Huh7-DRE-Luc cells and Huh7 cells). Ethoxyresorufin-O-deethylase (EROD) and DRE-luciferase assay were employed to determine the enzyme activity of cytochrome P450 1A1 (CYP1A1) and activation of AhR, respectively. The results showed that Cd 2+ levels significantly inhibited the induction of TCDD-induced CYP1A1 and DRE luciferase activation in hepatoma cells. The 50% inhibited concentrations (IC 50 ) of CdCl 2 were 0.414 μM (95% confidence interval (C.I.): 0.230-0.602 μM) in Huh7-DRE-Luc cells and 23.2 μM (95% C.I.: 21.7-25.4 μM) in Huh7 cells. Accordingly, prevention of interference with non-dioxin-like compounds in a DRE-luciferase assay is of great importance in an extensive cleanup procedure.

Clinicopathological study on the primary hepatoma of the atomic bomb survivors

Energy Technology Data Exchange (ETDEWEB)

Satoh, T; Takahara, O; Takahashi, N; Matsuo, K; Tsunoo, S [Nagasaki Atomic Bomb Hospital (Japan)

1978-09-01

Fifty-eight cases autopsied during 10 years from 1968 to 1977 were divided into (A) a non-exposed group, (B) a group exposed within 2 km of the center of explosion, and (C) a group exposed over 2 km from the center of explosion or a group who entered Nagasaki city after the explosion, and clinicopathological study on them was made in detail. These three groups were studied as to incidences according to age and sex, prognosis, histological types and hepatic lesion complicated by hepatoma in survival cases for more than one year, histological diagnosis, gross types, histological types, degree of atypia, hepatic lesion at sites not injured with hepatoma, and the detection rate of B-type virus hepatitis surface antigen (HBs-Ag). Pathohistologically, ordinary hematoxylin-eosin staining, van Gieson staining, silvering staining, iron staining were performed, and aldehyde-fuchsine staining was also performed HBs-Ag detection in a part of cases for.

Alkanna tinctoria leaves extracts: a prospective remedy against multidrug resistant human pathogenic bacteria.

Science.gov (United States)

Khan, Usman Ali; Rahman, Hazir; Qasim, Muhammad; Hussain, Anwar; Azizllah, Azizullah; Murad, Waheed; Khan, Zakir; Anees, Muhammad; Adnan, Muhammad

2015-04-23

Plants are rich source of chemical compounds that are used to accomplish biological activity. Indigenously crude extracts of plants are widely used as herbal medicine for the treatment of infections by people of different ethnic groups. The present investigation was carried out to evaluate the biological potential of Alkanna tinctoria leaves extract from district Charsadda, Pakistan against multidrug resistant human pathogenic bacteria including Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Anti-multi-drug resistant bacterial activity of aqueous, chloroform, ethanol and hexane extracts of Alkanna tinctoria leaves were evaluated by well diffusion method. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of different extracts were determined. Moreover qualitative phytochemicals screening of the studied extracts was performed. All four selected bacteria including A. baumannii, E. coli, P. aeruginosa and S. aureus were categorized as multi-drug resistant (MDR) as they were found to be resistant to 13, 10, 19 and 22 antibiotics belonging to different groups respectively. All the four extract showed potential activity against S. aureus as compare to positive control antibiotic (Imipenem). Similarly among the four extracts of Alkanna tinctoria leaves, aqueous extract showed best activity against A. baumannii (10±03 mm), P. aeruginosa (12±0.5 mm), and S. aureus (14±0.5 mm) as compare to Imipenem. The MICs and MBCs results also showed quantitative concentration of plant extracts to inhibit or kill MDR bacteria. When phytochemicals analysis was performed it was observed that aqueous and ethanol extracts showed phytochemicals with large number as well as volume, especially Alkaloides, Flavonoides and Charbohydrates. The undertaken study demonstrated that all the four extracts of Alkanna tinctoria leaves exhibited considerable antibacterial activity against MDR isolates. Finding from the

Bypassing multidrug resistance in human breast cancer cells with lipid/polymer particle assemblies

Directory of Open Access Journals (Sweden)

Li B

2012-01-01

Full Text Available Bo Li1, Hui Xu2, Zhen Li1, Mingfei Yao1, Meng Xie1, Haijun Shen1, Song Shen1, Xinshi Wang1, Yi Jin11College of Pharmaceutical sciences, Zhejiang University, Hangzhou, 2No. 202 Hospital of People's Liberation Army, Shenyang, ChinaBackground: Multidrug resistance (MDR mediated by the overexpression of adenosine triphosphate (ATP-binding cassette (ABC transporters, such as P-glycoprotein (P-gp, remains one of the major obstacles to effective cancer chemotherapy. In this study, lipid/particle assemblies named LipoParticles (LNPs, consisting of a dimethyldidodecylammonium bromide (DMAB-modified poly(lactic-co-glycolic acid (PLGA nanoparticle core surrounded by a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC shell, were specially designed for anticancer drugs to bypass MDR in human breast cancer cells that overexpress P-gp.Methods: Doxorubicin (DOX, a chemotherapy drug that is a P-gp substrate, was conjugated to PLGA and encapsulated in the self-assembled LNP structure. Physiochemical properties of the DOX-loaded LNPs were characterized in vitro. Cellular uptake, intracellular accumulation, and cytotoxicity were compared in parental Michigan Cancer Foundation (MCF-7 cells and P-gp-overexpressing, resistant MCF-7/adriamycin (MCF-7/ADR cells.Results: This study found that the DOX formulated in LNPs showed a significantly increased accumulation in the nuclei of drug-resistant cells relative to the free drug, indicating that LNPs could alter intracellular traffic and bypass drug efflux. The cytotoxicity of DOX loaded-LNPs had a 30-fold lower half maximal inhibitory concentration (IC50 value than free DOX in MCF-7/ADR, measured by the colorimetric cell viability (MTT assay, correlated with the strong nuclear retention of the drug.Conclusion: The results show that this core-shell lipid/particle structure could be a promising strategy to bypass MDR.Keywords: chemotherapy, drug delivery, polymeric nanoparticles, multidrug resistance

Studies on Anti-Hepatoma Effect of Gan-Ai-Xiao Decoction | Yuan ...

African Journals Online (AJOL)

Purpose: To explore the anti-hepatoma effect of Gan-Ai-Xiao Decoction (GAXD), a folk remedy. Methods: High performance liquid chromatography (HPLC) was used to identify the major chemical components of GAXD ethanol extract (EE). The cytotoxic effect of GAXD EE against HepG2 cells was measured by methyl ...

Effects of drugs in subtoxic concentrations on the metabolic fluxes in human hepatoma cell line Hep G2

International Nuclear Information System (INIS)

Niklas, Jens; Noor, Fozia; Heinzle, Elmar

2009-01-01

Commonly used cytotoxicity assays assess the toxicity of a compound by measuring certain parameters which directly or indirectly correlate to the viability of the cells. However, the effects of a given compound at concentrations considerably below EC 50 values are usually not evaluated. These subtoxic effects are difficult to identify but may eventually cause severe and costly long term problems such as idiosyncratic hepatotoxicity. We determined the toxicity of three hepatotoxic compounds, namely amiodarone, diclofenac and tacrine on the human hepatoma cell line Hep G2 using an online kinetic respiration assay and analysed the effects of subtoxic concentrations of these drugs on the cellular metabolism by using metabolic flux analysis. Several changes in the metabolism could be detected upon exposure to subtoxic concentrations of the test compounds. Upon exposure to diclofenac and tacrine an increase in the TCA-cycle activity was observed which could be a signature of an uncoupling of the oxidative phosphorylation. The results indicate that metabolic flux analysis could serve as an invaluable novel tool for the investigation of the effects of drugs. The described methodology enables tracking the toxicity of compounds dynamically using the respiration assay in a range of concentrations and the metabolic flux analysis permits interesting insights into the changes in the central metabolism of the cell upon exposure to drugs.

The Reversal Effects of 3-Bromopyruvate on Multidrug Resistance In Vitro and In Vivo Derived from Human Breast MCF-7/ADR Cells

OpenAIRE

Wu, Long; Xu, Jun; Yuan, Weiqi; Wu, Baojian; Wang, Hao; Liu, Guangquan; Wang, Xiaoxiong; Du, Jun; Cai, Shaohui

2014-01-01

Purpose P-glycoprotein mediated efflux is one of the main mechanisms for multidrug resistance in cancers, and 3-Bromopyruvate acts as a promising multidrug resistance reversal compound in our study. To test the ability of 3-Bromopyruvate to overcome P-glycoprotein-mediated multidrug resistance and to explore its mechanisms of multidrug resistance reversal in MCF-7/ADR cells, we evaluate the in vitro and in vivo modulatory activity of this compound. Methods The in vitro and in vivo activity wa...

Expression of human α-fetoprotein in yeast

International Nuclear Information System (INIS)

Yamamoto, Ritsu; Sakamoto, Takashi; Nishi, Shinzo; Sakai, Masaharu; Morinaga, Tomonori; Tamaoki, Taiki

1990-01-01

Human α-fetoprotein (AFP) was expressed in Saccharomyces cerevisiae, with a plasmid containing the cDNA sequence for human AFP fused with the rat AFP signal peptide. The recombinant AFP was purified from the yeast lysate by DEAE-cellulose and immunoaffinity chromatography. The amino acid composition and the molecular weight of the recombinant AFP were similar to those of hepatoma AFP. N-terminal amino acids sequence analysis indicated that the signal peptide had been processed. The recombinant and hepatoma AFP reacted identically in Ouchterlony immunodiffusion and radioimmunoassay tests. These observations indicated that the yeast recombinant protein had the properties of native AFP

Variables affecting the tumor localization of 131I-antiferritin in experimental hepatoma

International Nuclear Information System (INIS)

Rostock, R.A.; Klein, J.L.; Kopher, K.A.; Order, S.E.

1984-01-01

Ferritin is both a normal tissue- and tumor-associated protein. The in vivo localization of 131 I-radiolabeled antitumor ferritin and normal IgG antibodies in the H-4-II-E rat hepatoma model was investigated in both tumor and normal tissues over a dose range of 0.67 micrograms to 5 mg of normal and antiferritin IgG and at labeling ratios (microCi 131 I per micrograms IgG) of 15:1, 5:1, and 1:10. The total dose from nonpenetrating radiation in rads was calculated and demonstrated a maximum of 2.9 times greater dose deposition (rads) of antiferritin than normal IgG in hepatoma without specific increase in binding in normal tissues. The maximum tumor targeting achieved was dependent on the amount of injected IgG and not on the labeling ratio or procedure. The binding in tumor could be inhibited by unlabeled antiferritin but not by unlabeled normal rabbit IgG and demonstrated the requirement of specificity for tumor binding. Normal tissues did not target with antiferritin. Most normal tissues have a capacity to bind normal and antiferritin IgG nonspecifically that is linear in relationship to the amount of injected IgG. The results demonstrate that 131 I-antiferritin selectively targets ferritin-secreting hepatoma over normal tissues and that the amount of targeting is dependent on the amount of antiferritin injected. The physiologic reasons for such selective localization is not known, but the term ''biologic window'' has been used to describe the differential availability of tumor ferritin for binding

Multidrug-resistant opportunistic pathogens challenging veterinary infection control.

Science.gov (United States)

Walther, Birgit; Tedin, Karsten; Lübke-Becker, Antina

2017-02-01

Although the problems associated with healthcare-associated infections (HAI) and the emergence of zoonotic and multidrug-resistant pathogens in companion animal (dogs, cats and horses) medicine have been well-known for decades, current progress with respect to practical implementation of infection control programs in veterinary clinics has been limited. Clinical outbreak events reported for methicillin-resistant Staphylooccus aureus (MRSA) and Staphylococcus pseudintermedius (MRSP), extended spectrum beta-lactamase (ESBL)-producing Escherichia coli and multidrug-resistant (MDR) Salmonella Serovars indicate the necessity of infection control strategies for protecting animal patients at risk as well as veterinary personnel. The close bond between humans and their companion animals provides opportunities for exchange of microorganisms, including MDR pathogens. This particular aspect of the "One Health" idea requires more representative surveillance efforts and infection control strategies with respect to animal-species specific characters. Copyright © 2016 Elsevier B.V. All rights reserved.

Multidrug-resistant pathogens in the food supply.

Science.gov (United States)

Doyle, Marjorie E

2015-04-01

Antimicrobial resistance, including multidrug resistance (MDR), is an increasing problem globally. MDR bacteria are frequently detected in humans and animals from both more- and less-developed countries and pose a serious concern for human health. Infections caused by MDR microbes may increase morbidity and mortality and require use of expensive drugs and prolonged hospitalization. Humans may be exposed to MDR pathogens through exposure to environments at health-care facilities and farms, livestock and companion animals, human food, and exposure to other individuals carrying MDR microbes. The Centers for Disease Control and Prevention classifies drug-resistant foodborne bacteria, including Campylobacter, Salmonella Typhi, nontyphoidal salmonellae, and Shigella, as serious threats. MDR bacteria have been detected in both meat and fresh produce. Salmonellae carrying genes coding for resistance to multiple antibiotics have caused numerous foodborne MDR outbreaks. While there is some level of resistance to antimicrobials in environmental bacteria, the widespread use of antibiotics in medicine and agriculture has driven the selection of a great variety of microbes with resistance to multiple antimicrobials. MDR bacteria on meat may have originated in veterinary health-care settings or on farms where animals are given antibiotics in feed or to treat infections. Fresh produce may be contaminated by irrigation or wash water containing MDR bacteria. Livestock, fruits, and vegetables may also be contaminated by food handlers, farmers, and animal caretakers who carry MDR bacteria. All potential sources of MDR bacteria should be considered and strategies devised to reduce their presence in foods. Surveillance studies have documented increasing trends in MDR in many pathogens, although there are a few reports of the decline of certain multidrug pathogens. Better coordination of surveillance programs and strategies for controlling use of antimicrobials need to be implemented in

Alpha-feto protein radioimmunoassay and its values for the diagnosis of hepatoma among normal Japanese population and those with chronic schistosomiasis

International Nuclear Information System (INIS)

Lio, Masahiro; Yamada, Hideo; Luchi, Masahiko

1972-01-01

Since its first report made by Ablevet al., α-feto protein which appears both in fetal serum and serum in the cases with hepatoma drew attention of hepatologist in order to establish an qualitative method to diagnose the presence of hepatoma. Since conventional liver scintigraphy is not able to make the diagnosis of the nature of lesion which appears as space occupying lesion need for the more qualitative method facilitated the establishment of the method to detect the presence of α-feto protein in serum. α-feto protein in the serum of hepatoma cases was reported to be identical to fetal α-feto protein by the immunological method. At first, assay of the α-feto protein was performed using the precipitation reaction in agar gel and became quite popular among clinical hepatologist. Detection sensitivity of this conventional method, however, is approximately 10 μgr/ml and α-feto protein was detected in 80% of hepatoma patient. However detection percentage of the hepatoma cases associated with chronic schistosomiasis was found to be as poor as 30% which was measured by our group at Kofu municipal Hospital. Because of the frequent incidences of deformed and small liver by scintigraphy among cases with chronic schistosomiasis and these abnormal liver scintigraphy easily lead one to middiagnose the presence of hepatoma, establishment of more sensitive assay method is needed. After the success of purification and crystallization of the α-feto protein by the group of Univ. of Hokkaido, the radioimmunoassay technique was developed in Japan and α-feto-125 Kit is now became available commercially. Initial trial of this new promising and this double antibody technique enabled us to measure 2 mμgr/ml of α-feto protein which was almost 500-1,000 times more sensitive than those of the conventional method.

Study on the damage effect of 131I-iodinated oil internal radiation in SMMC-7721 hepatoma model in rat

International Nuclear Information System (INIS)

Wu Shuyan; Zhang Xuguang; Wang Xiangying; Li Su'an; Mao Dihua

2004-01-01

Objective: To investigate the damage effect of 131 I-iodinated oil internal radiation in hepatoma. Methods: SMMC-7721 rat hepatoma model was used to evaluate the damage of 131 I-iodinated oil internal radiation in carcinoma. 131 I-iodinated oil was injected sector-shapely into tumor model of SMMC-7721 hepatoma with arc-needle, matched with routine straight-needle injection. Tumor damage induced by 131 I-iodinated oil intralesion radiation in the carcinoma models are recorded through survival time, weight of rat, local carcinoma, pathology, electron microscopy. Results: Arc-needle injection 131 I-iodinated oil in SMMC-7721 hepatoma at subcutis could increase rat's survival time, the body weight kept less descent, the lumps necrosed wholly. Pathology and ultrastructure detection revealed cell necrosis and collapse, sever nuclear damage was observed in the death cells. The early characteristics of necrosis such as margination of heterochromatin was also found in some tumor cells. Besides, well differentiated tumor cells, degenerative tumor cells and some lymphocytes were seen. Conclusion: Arc-needle injection 131 I-iodinated oil step-by step sector-shapely into tumor is a better method and necrosis is the major effect of 131 I-iodinated oil internal radiation in carcinoma at the level of treated dosage

Radiosensitizing effects of 9401 on mice bearing H22 hepatoma

International Nuclear Information System (INIS)

Liu Xiaoqiu; Wang Qin; Zhou Zewei; Han Ying; Wang Dezhi; Shen Xiu

2013-01-01

Objective: To investigate the radiosensitizing effects of 9401 on mice bearing H22 hepatoma. Methods: Mouse model bearing H22 hepatoma cells were established. Mice were randomly divided into six groups, the control group,the radiation group and four treatment groups including 9401 at high, medium and low dosages and nicotinamide combined with radiation. After irradiated, the growth of tumor was observed, the time of tumor growth was recorded, the delay time of tumor growth and enhancement factor (EF) were calculated. After 28 days, the mice were killed, the tumors were stripped and inhibition rate was calculated. Results: Groups of 9401 combined with radiation could postpone tumor growth. The difference was statistically significant between 9401 groups at high, medium dosages combined with radiation and nicotinamide combined with radiation group (t=24.7 and 7.5, both P<0.01). Compared with radiation alone group, groups of 9401 combined with radiation had significant radiosensitizing effect. The enhancement factor of 9401 combined with radiation groups at high and medium dosages were 2.13 and 1.73 respectively, they were significant higher than nicotinamide combined with radiation group (t=2.26 and 9.04, both P<0.05). The inhibition rate of 9401 groups at high, medium and low dosages combined with radiation were 64.5%, 50.9% and 42.6% respectively. The inhibition rate of nicotinamide group combined radiation was 53.2%. The inhibition rate of 9401 at high dosage combined with radiation had significant difference with nicotinamide combined radiation (t =2.8, P<0.05). Nicotinamide combined with radiation group, 9401 combined with radiation groups could significant inhibit the growth of tumors compared with radiation alone group (t=5.7, 4.0 and 2.2, all P<0.05). Conclusion: 9401 can inhibit the tumor growth and the inhibition effect increases gradually with the drug dose increasing. It also has radiosensitizing effects on mice bearing H22 hepatoma and present broadly

Indolcarboxamide is a preclinical candidate for treating multidrug-resistant tuberculosis.

Science.gov (United States)

Rao, Srinivasa P S; Lakshminarayana, Suresh B; Kondreddi, Ravinder R; Herve, Maxime; Camacho, Luis R; Bifani, Pablo; Kalapala, Sarath K; Jiricek, Jan; Ma, Ng L; Tan, Bee H; Ng, Seow H; Nanjundappa, Mahesh; Ravindran, Sindhu; Seah, Peck G; Thayalan, Pamela; Lim, Siao H; Lee, Boon H; Goh, Anne; Barnes, Whitney S; Chen, Zhong; Gagaring, Kerstin; Chatterjee, Arnab K; Pethe, Kevin; Kuhen, Kelli; Walker, John; Feng, Gu; Babu, Sreehari; Zhang, Lijun; Blasco, Francesca; Beer, David; Weaver, Margaret; Dartois, Veronique; Glynne, Richard; Dick, Thomas; Smith, Paul W; Diagana, Thierry T; Manjunatha, Ujjini H

2013-12-04

New chemotherapeutic compounds against multidrug-resistant Mycobacterium tuberculosis (Mtb) are urgently needed to combat drug resistance in tuberculosis (TB). We have identified and characterized the indolcarboxamides as a new class of antitubercular bactericidal agent. Genetic and lipid profiling studies identified the likely molecular target of indolcarboxamides as MmpL3, a transporter of trehalose monomycolate that is essential for mycobacterial cell wall biosynthesis. Two lead candidates, NITD-304 and NITD-349, showed potent activity against both drug-sensitive and multidrug-resistant clinical isolates of Mtb. Promising pharmacokinetic profiles of both compounds after oral dosing in several species enabled further evaluation for efficacy and safety. NITD-304 and NITD-349 were efficacious in treating both acute and chronic Mtb infections in mouse efficacy models. Furthermore, dosing of NITD-304 and NITD-349 for 2 weeks in exploratory rat toxicology studies revealed a promising safety margin. Finally, neither compound inhibited the activity of major cytochrome P-450 enzymes or the hERG (human ether-a-go-go related gene) channel. These results suggest that NITD-304 and NITD-349 should undergo further development as a potential treatment for multidrug-resistant TB.

Identification of microRNAs and mRNAs associated with multidrug resistance of human laryngeal cancer Hep-2 cells

Energy Technology Data Exchange (ETDEWEB)

Yin, Wanzhong; Wang, Ping; Wang, Xin [Department of Otorhinolaryngology, Head and Neck Surgery, The First Clinical Hospital, Norman Bethune College of Medicine, Jilin University, Changchun (China); Song, Wenzhi [Department of Stomatology, China-Japan Friendship Hospital, Jilin University, Changchun (China); Cui, Xiangyan; Yu, Hong; Zhu, Wei [Department of Otorhinolaryngology, Head and Neck Surgery, The First Clinical Hospital, Norman Bethune College of Medicine, Jilin University, Changchun (China)

2013-06-12

Multidrug resistance (MDR) poses a serious impediment to the success of chemotherapy for laryngeal cancer. To identify microRNAs and mRNAs associated with MDR of human laryngeal cancer Hep-2 cells, we developed a multidrug-resistant human laryngeal cancer subline, designated Hep-2/v, by exposing Hep-2 cells to stepwise increasing concentrations of vincristine (0.02-0.96'µM). Microarray assays were performed to compare the microRNA and mRNA expression profiles of Hep-2 and Hep-2/v cells. Compared to Hep-2 cells, Hep-2/v cells were more resistant to chemotherapy drugs (∼45-fold more resistant to vincristine, 5.1-fold more resistant to cisplatin, and 5.6-fold more resistant to 5-fluorouracil) and had a longer doubling time (42.33±1.76 vs 28.75±1.12'h, P<0.05), higher percentage of cells in G0/G1 phase (80.98±0.52 vs 69.14±0.89, P<0.05), increased efflux of rhodamine 123 (95.97±0.56 vs 12.40±0.44%, P<0.01), and up-regulated MDR1 expression. A total of 7 microRNAs and 605 mRNAs were differentially expressed between the two cell types. Of the differentially expressed mRNAs identified, regulator of G-protein signaling 10, high-temperature requirement protein A1, and nuclear protein 1 were found to be the putative targets of the differentially expressed microRNAs identified. These findings may open a new avenue for clarifying the mechanisms responsible for MDR in laryngeal cancer.

Identification of microRNAs and mRNAs associated with multidrug resistance of human laryngeal cancer Hep-2 cells

International Nuclear Information System (INIS)

Yin, Wanzhong; Wang, Ping; Wang, Xin; Song, Wenzhi; Cui, Xiangyan; Yu, Hong; Zhu, Wei

2013-01-01

Multidrug resistance (MDR) poses a serious impediment to the success of chemotherapy for laryngeal cancer. To identify microRNAs and mRNAs associated with MDR of human laryngeal cancer Hep-2 cells, we developed a multidrug-resistant human laryngeal cancer subline, designated Hep-2/v, by exposing Hep-2 cells to stepwise increasing concentrations of vincristine (0.02-0.96'µM). Microarray assays were performed to compare the microRNA and mRNA expression profiles of Hep-2 and Hep-2/v cells. Compared to Hep-2 cells, Hep-2/v cells were more resistant to chemotherapy drugs (∼45-fold more resistant to vincristine, 5.1-fold more resistant to cisplatin, and 5.6-fold more resistant to 5-fluorouracil) and had a longer doubling time (42.33±1.76 vs 28.75±1.12'h, P<0.05), higher percentage of cells in G0/G1 phase (80.98±0.52 vs 69.14±0.89, P<0.05), increased efflux of rhodamine 123 (95.97±0.56 vs 12.40±0.44%, P<0.01), and up-regulated MDR1 expression. A total of 7 microRNAs and 605 mRNAs were differentially expressed between the two cell types. Of the differentially expressed mRNAs identified, regulator of G-protein signaling 10, high-temperature requirement protein A1, and nuclear protein 1 were found to be the putative targets of the differentially expressed microRNAs identified. These findings may open a new avenue for clarifying the mechanisms responsible for MDR in laryngeal cancer

Antibacterial activities of Rhazya stricta leaf extracts against multidrug-resistant human pathogens

Directory of Open Access Journals (Sweden)

Raziuddin Khan

2016-09-01

Full Text Available Bacterial resistance to antibiotics, first a major concern in the 1960s, has re-emerged worldwide over the last 20 years. The World Health Organization (WHO and other health organizations have, therefore, declared ‘war’ against human microbial pathogens, particularly hospital-acquired infections, and have made drug discovery a top priority for these diseases. Because these bacteria are refractory to conventional chemotherapy, medicinal and herbal plants used in various countries should be assessed for their therapeutic potential; these valuable bio-resources are a reservoir of complex bioactive molecules. Earlier studies from our laboratory on Rhazya stricta, a native herbal shrub of Asia, have shown that this plant has a number of therapeutic properties. In this study, we evaluated the antimicrobial activities of various concentrations of five solvent extracts (aqueous alkaloid, aqueous non-alkaloid, organic alkaloid, organic non-alkaloid and whole aqueous extracts derived from R. stricta leaves against several multidrug-resistant, human-pathogenic bacteria, including methicillin-resistant Staphylococcus aureus (MRSA and extended-spectrum beta-lactamase-positive Escherichia coli. In vitro, molecular and electron microscopy analyses conclusively demonstrated the antimicrobial effects of these extracts against a panel of Gram-negative and Gram-positive bacteria. The organic alkaloid extract was the most effective against E. coli and MRSA, resulting in cell membrane disruption visible with transmission electron microscopy. In the near future, we intend to further focus and delineate the molecular mechanism-of-action for specific alkaloids of R. stricta, particularly against MRSA.

Hydrogen sulfide (H2S)/cystathionine γ-lyase (CSE) pathway contributes to the proliferation of hepatoma cells

International Nuclear Information System (INIS)

Pan, Yan; Ye, Shuang; Yuan, Dexiao; Zhang, Jianghong; Bai, Yang; Shao, Chunlin

2014-01-01

Highlights: • Inhibition of H 2 S/CSE pathway strongly stimulates cellular apoptosis. • Inhibition of H 2 S/CSE pathway suppresses cell growth by blocking EGFR pathway. • H 2 S/CSE pathway is critical for maintaining the proliferation of hepatoma cells. - Abstract: Hydrogen sulfide (H 2 S)/cystathionine γ-lyase (CSE) pathway has been demonstrated to play vital roles in physiology and pathophysiology. However, its role in tumor cell proliferation remains largely unclear. Here we found that CSE over-expressed in hepatoma HepG2 and PLC/PRF/5 cells. Inhibition of endogenous H 2 S/CSE pathway drastically decreased the proliferation of HepG2 and PLC/PRF/5 cells, and it also enhanced ROS production and mitochondrial disruption, pronounced DNA damage and increased apoptosis. Moreover, this increase of apoptosis was associated with the activation of p53 and p21 accompanied by a decreased ratio of Bcl-2/Bax and up-regulation of phosphorylated c-Jun N-terminal kinase (JNK) and caspase-3 activity. In addition, the negative regulation of cell proliferation by inhibition of H 2 S/CSE system correlated with the blockage of cell mitogenic and survival signal transduction of epidermal growth factor receptor (EGFR) via down-regulating the extracellular-signal-regulated kinase 1/2 (ERK1/2) activation. These results demonstrate that H 2 S/CSE and its downstream pathway contribute to the proliferation of hepatoma cells, and inhibition of this pathway strongly suppress the excessive growth of hepatoma cells by stimulating mitochondrial apoptosis and suppressing cell growth signal transduction

Fluoro-sorafenib (Regorafenib) effects on hepatoma cells: growth inhibition, quiescence and recovery

Science.gov (United States)

Carr, Brian I.; Cavallini, Aldo; Lippolis, Catia; D’Alessandro, Rosalba; Messa, Caterina; Refolo, Maria Grazia; Tafaro, Angela

2015-01-01

To evaluate the growth-inhibitory properties of the potent multi-kinase antagonist Regorafenib (Fluoro-Sorafenib), which was synthesized as a more potent Sorafenib, a Raf inhibitor and to determine whether similar mechanisms were involved, human hepatoma cell lines were grown in the presence or absence of Regorafanib and examined for growth inhibition. Western blots were performed for Raf targets, for apoptosis and autophagy. Regorafenib inhibited growth of human Hep3B, PLC/PRF/5 and HepG2 cells in a concentration- and time-dependent manner. Multiple signaling pathways were altered, including MAP kinases phospho-ERK and phospho-JNK and its target phospho-c-Jun. There was evidence for apoptosis by FACS, cleavage of caspases and increased Bax levels; as well as induction of autophagy, as judged by increased Beclin-1 and LC3 (II) levels. Prolonged drug exposure resulted in cell quiescence. Full growth recovery occurred after drug removal, unlike with doxorubicin chemotherapy. Regorafenib is a potent inhibitor of cell growth. Cells surviving Regorafenib treatment remain viable, but quiescent and capable of regrowth following drug removal. The reversibility of tumor cell growth suppression after drug removal may have clinical implications. PMID:22777740

The imaging feature of multidrug-resistant tuberculosis

International Nuclear Information System (INIS)

Yang Jun; Zhou Xinhua; Li Xi; Fu Yuhong; Zheng Suhua; Lv Pingxin; Ma Daqing

2004-01-01

Objective: To evaluate the imaging features of multidrug-resistant tuberculosis by collecting multidrug-resistant tuberculosis verified by test of drug-sensitivity, which defined as resistance to three anti-tuberculosis drugs. Methods:Fifty-one cases of multidrug-resistant tuberculosis were categorized as group of observed, and 46 cases of drug sensitive tuberculosis were categorized as control. Cultures were positive for Mycobacterium tuberculosis in all cases with no other illness such as diabetes mellitus. All patients had chest radiographs available for review, while 64 cases had tomography and 30 cases had CT during the same time. All images were analyzed by three of the radiologists, disagreement among them was discussed and a consensus was reached. Results: There was no difference in the distribution of lesions between the multidrug-resistant tuberculosis group and control group. However, the radiological findings in the multidrug-resistant tuberculosis group were significantly more common than in control group, such as multiple nodules (10 cases), disseminated foci (23 cases), cavity (9 cases), and complications (10 cases). Comparing the dynamic cases, deteriorating cases were more commonly seen in observed group than in control group, while improved cases were less in observed group than in control group. Conclusion: Multidrug-resistant tuberculosis is the most serious tuberculosis, which is characterized with significant activity, more disseminated foci, cavity, and complications. The lesion deteriorated while correct anti-tuberculosis treatment is applied. (authors)

Hepatitis B virus X protein mutant HBxΔ127 promotes proliferation of hepatoma cells through up-regulating miR-215 targeting PTPRT

Energy Technology Data Exchange (ETDEWEB)

Liu, Fabao [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China); Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China); You, Xiaona [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China); Chi, Xiumei [Department of Hepatology, The First Hospital, Jilin University, Changchun 130021 (China); Wang, Tao [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ye, Lihong [Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China); Niu, Junqi, E-mail: junqiniu@yahoo.com.cn [Department of Hepatology, The First Hospital, Jilin University, Changchun 130021 (China); Zhang, Xiaodong, E-mail: zhangxd@nankai.edu.cn [Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China)

2014-02-07

Highlights: • Relative to wild type HBx, HBX mutant HBxΔ127 strongly enhances cell proliferation. • Relative to wild type HBx, HBxΔ127 remarkably up-regulates miR-215 in hepatoma cells. • HBxΔ127-elevated miR-215 promotes cell proliferation via targeting PTPRT mRNA. - Abstract: The mutant of virus is a frequent event. Hepatitis B virus X protein (HBx) plays a vital role in the development of hepatocellular carcinoma (HCC). Therefore, the identification of potent mutant of HBx in hepatocarcinogenesis is significant. Previously, we identified a natural mutant of the HBx gene (termed HBxΔ127). Relative to wild type HBx, HBxΔ127 strongly enhanced cell proliferation and migration in HCC. In this study, we aim to explore the mechanism of HBxΔ127 in promotion of proliferation of hepatoma cells. Our data showed that both wild type HBx and HBxΔ127 could increase the expression of miR-215 in hepatoma HepG2 and H7402 cells. However, HBxΔ127 was able to significantly increase miR-215 expression relative to wild type HBx in the cells. We identified that protein tyrosine phosphatase, receptor type T (PTPRT) was one of the target genes of miR-215 through targeting 3′UTR of PTPRT mRNA. In function, miR-215 was able to promote the proliferation of hepatoma cells. Meanwhile anti-miR-215 could partially abolish the enhancement of cell proliferation mediated by HBxΔ127 in vitro. Knockdown of PTPRT by siRNA could distinctly suppress the decrease of cell proliferation mediated by anti-miR-215 in HepG2-XΔ127/H7402-XΔ127 cells. Moreover, we found that anti-miR-215 remarkably inhibited the tumor growth of hepatoma cells in nude mice. Collectively, relative to wild type HBx, HBxΔ127 strongly enhances proliferation of hepatoma cells through up-regulating miR-215 targeting PTPRT. Our finding provides new insights into the mechanism of HBx mutant HBxΔ127 in promotion of proliferation of hepatoma cells.

Functional characterization of the human multidrug transporter, ABCG2, expressed in insect cells

DEFF Research Database (Denmark)

Ozvegy, C.; Litman, Thomas; Szakacs, G.

2001-01-01

ABCG2 (also called MXR (3), BCRP (4), or ABCP (5) is a recently-identified ABC half-transporter, which causes multidrug resistance in cancer. Here we report that the expression of the ABCG2 protein in Sf9 insect cells resulted in a high-capacity, vanadate-sensitive ATPase activity in isolated...

Cell surface GRP78 facilitates hepatoma cells proliferation and migration by activating IGF-IR.

Science.gov (United States)

Yin, Yancun; Chen, Chen; Chen, Jinliang; Zhan, Renhui; Zhang, Qiang; Xu, Xiaoyan; Li, Defang; Li, Minjing

2017-07-01

The 78kDa glucose regulated protein (GRP78) is a multifunctional chaperone that is involved in a variety of cellular processes. Insulin like growth factor I receptor (IGF-IR) often aberrant expresses in many types of tumor cells. The IGF-IR signaling plays key roles in carcinogenesis and maintenance of the malignant phenotype. The crosstalk between GRP78 and IGF-IR molecules has not well been illuminated. Here, we demonstrated a reciprocal regulation of GRP78 expression and IGF-IR pathway activation. IGF-I induced GRP78 expression in hepatoma cells. IGF-IR knockdown or IGF-IR inhibitor repressed GRP78 expression. Both phosphatidylinositol 3-kianase (PI3K) and mitogen-activated protein kinase (MAPK) pathways involved in IGF-I induction of GRP78 expression. Interestingly, treatment of hepatoma cells with IGF-I re-distributes GRP78 from endoplasmic reticulum (ER) to cell surface and promotes its physical interaction with IGF-IR. Also, GRP78 promotes IGF-IR phosphorylation and activation. Blocked of GRP78 by small interfering RNA or inhibition of GRP78 function by (-)-epigallocatechin gallate (EGCG) blocks IGF-I induced IGF-IR phosphorylation and its downstream signaling. Further, blocked cell surface GRP78 with antibody inhibits IGF-I stimulated cellular proliferation and migration. These data reveal an essential role for the molecular chaperone GRP78 in IGF-IR signaling and implicate the use of GRP78 inhibitors in blocking IGF-IR signaling in hepatoma cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Multidrug Efflux Systems in Microaerobic and Anaerobic Bacteria

OpenAIRE

Xu, Zeling; Yan, Aixin

2015-01-01

Active drug efflux constitutes an important mechanism of antibiotic and multidrug resistance in bacteria. Understanding the distribution, expression, and physiological functions of multidrug efflux pumps, especially under physiologically and clinically relevant conditions of the pathogens, is the key to combat drug resistance. In animal hosts, most wounded, infected and inflamed tissues display low oxygen tensions. In this article, we summarize research development on multidrug efflux pumps i...

Multidrug-Resistant Candida

DEFF Research Database (Denmark)

Arendrup, Maiken Cavling; Patterson, Thomas F

2017-01-01

Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance...... can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients....... Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites...

A bacterial antibiotic-resistance gene that complements the human multidrug-resistance P-glycoprotein gene

NARCIS (Netherlands)

van Veen, HW; Callaghan, R; Soceneantu, L; Sardini, A; Konings, WN; Higgins, CF

1998-01-01

Bacteria have developed many fascinating antibiotic-resistance mechanisms(1,2). A protein in Lactococcus lactis, LmrA, mediates antibiotic resistance by extruding amphiphilic compounds from the inner leaflet of the cytoplasmic membrane(3,4). Unlike other known bacterial multidrug-resistance

Synthesis, Antiproliferative, and Multidrug Resistance Reversal Activities of Heterocyclic α,β-Unsaturated Carbonyl Compounds.

Science.gov (United States)

Sun, Ju-Feng; Hou, Gui-Ge; Zhao, Feng; Cong, Wei; Li, Hong-Juan; Liu, Wen-Shuai; Wang, Chunhua

2016-10-01

A series of heterocyclic α,β-unsaturated carbonyl compounds (1a-1d, 2a-2d, 3a-3d, 4a-3d, and 5a-5d) with 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore were synthesized for the development of anticancer and multidrug resistance reverting agents. The antiproliferative activities were tested against nine human cancer cell lines. Approximately 73% of the IC50 values were below 5 μm, while 35% of these figures were submicromolar, and compounds 3a-3d with 4-trifluoro methyl in the arylidene benzene rings were the most potent, since their IC50 values are between 0.06 and 3.09 μm against all cancer cell lines employed. Meanwhile, their multidrug resistance reversal properties and cellular uptake were further examined. The data displayed that all of these compounds could reverse multidrug resistance, particularly, compounds 3a and 4a demonstrated both potent multidrug resistance reverting properties and strong antiproliferative activities, which can be taken as leading molecules for further research of dual effect agents in tumor chemotherapy. © 2016 John Wiley & Sons A/S.

Expression of rat class I major histocompatibility complex (MHC) alloantigens and hepatocytes and hepatoma cells

International Nuclear Information System (INIS)

Hunt, J.M.; Desai, P.A.; Chakraborty, S.

1986-01-01

Altered expression of Class I MHC alloantigens has been reported for murine tumors, and may be associated with the tumorigenic phenotype of tumor cells. To characterize MHC Class I alloantigen expression on a chemically-induced transplantable rat hepatoma cell line, 17X, derived from a (WF x F344) F 1 rat, polyvalent anti-F344 and anti-WF rat alloantisera were first used to immunoprecipitate the rat RT1.A Class I MHC alloantigens expressed on primary (WF x F344) F 1 hepatocyptes in short-term monolayer cultures. Two-dimensional isoelectric focusing and SDS-PAGE of immunoprecipitates from 35 S-methionine-labeled (WF x F344) F 1 hepatocytes clearly resolved the RT1.A/sup u/ (WF) and RT1.A/sup LvI/ (F344) parental alloantigens. Identical radiolabeling and immunoprecipitation failed to detect either parental alloantigen on the 17X hepatoma cells. However, indirect immunofluorescence and immunoblot analyses demonstrated the presence of parental alloantigens on the 17X cells. Immunization of F344 rats but not of WF rats with 17X cells resulted in antibodies cytotoxic for normal (WF X F344) F 1 spleen cells in the presence of complement. These findings indicate that a combination of detection techniques will be necessary to characterize altered alloantigen expression on rat hepatoma cells

miR-150-5p inhibits hepatoma cell migration and invasion by targeting MMP14.

Directory of Open Access Journals (Sweden)

Tao Li

Full Text Available Hepatocellular carcinoma (HCC is one of the leading causes of cancer-related mortality worldwide. Despite progress in diagnostics and treatment of HCC, its prognosis remains poor because the molecular mechanisms underlying hepatocarcinogenesis are not well understood. In the study, we focused on identifying the role of miRNAs in HCC progression. miRNA microarray was used to analyze the differentially expressed miRNAs, and the results were validated by qPCR. We found that the miR-150-5p expression is down-regulated in HCC tissues compared with pair non-tumor tissues. miR-150-5p expression is also decreased in metastatic cancer tissues compared with pair primary tissues, indicating that miR-150-5p may be involved in HCC metastasis. Functionally, miR-150-5p inhibition significantly promotes hepatoma cell migration and invasion, whereas miR-150-5p overexpression suppresses cancer cell migration and invasion in vitro. The matrix metalloproteinase 14 (MMP14 is identified as a new target gene of miR-150-5p. miR-150-5p markedly inhibits MMP14 expression in hepatoma cells, and miR-150-5p expression is negative correlation with MMP14 expression in vivo. More important, re-expression of MMP14 in hepatoma cells partially reverses the effect of miR-150-5p in inhibiting cell invasion.

Genotoxicity assessment of membrane concentrates of landfill leachate treated with Fenton reagent and UV-Fenton reagent using human hepatoma cell line.

Science.gov (United States)

Wang, Guifang; Lu, Gang; Yin, Pinghe; Zhao, Ling; Yu, Qiming Jimmy

2016-04-15

Membrane concentrates of landfill leachates contain organic and inorganic contaminants that could be highly toxic and carcinogenic. In this paper, the genotoxicity of membrane concentrates before and after Fenton and UV-Fenton reagent was assessed. The cytotoxicity and genotoxicity was determined by using the methods of methyltetrazolium (MTT), cytokinesis-block micronucleus (CBMN) and comet assay in human hepatoma cells. MTT assay showed a cytotoxicity of 75% after 24h of exposure to the highest tested concentration of untreated concentrates, and no cytotoxocity for UV-Fenton and Fenton treated concentrates. Both CBMN and comet assays showed increased levels of genotoxicity in cells exposed to untreated concentrates, compared to those occurred in cells exposed to UV-Fenton and Fenton reagent treated concentrates. There was no significant difference between negative control and UV-Fenton treated concentrates for micronucleus and comet assay parameters. UV-Fenton and Fenton treatment, especially the former, were effective methods for degradation of bisphenol A and nonylphenol in concentrates. These findings showed UV-Fenton and Fenton reaction were effective methods for treatment of such complex concentrates, UV-Fenton reagent provided toxicological safety of the treated effluent, and the genotoxicity assays were found to be feasible tools for assessment of toxicity risks of complex concentrates. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of the Interaction between P-Glycoprotein and Anxa2 in Multidrug-resistant Human Breast Cancer Cells

International Nuclear Information System (INIS)

Zhang, Hai-chang; Zhang, Fei; Wu, Bing; Han, Jing-hua; Ji, Wei; Zhou, Yan; Niu, Rui-fang

2012-01-01

To explore the interaction of Anxa2 with P-Glycoprotein (P-gp) in the migration and invasion of the multidrug-resistant (MDR) human breast cancer cell line MCF-7/ADR. A pair of short hairpin RNA (shRNA) targeting P-gp was transfected into MCF-7/ADR cells, and monoclonal cell strains were screened. The expression of P-gp was detected by Western blot. Transwell chambers were used to observe the cell migration capacity and invasion ability. The interaction between P-gp and Anxa2 was examined by immunoprecipitation and immunofluorescence confocal microscopy analyses. P-gp expression was significantly knocked down, and there were notable decreasing trends in the migration and invasion capability of MDR breast cancer cells (P<0.05). There was a close interaction between Anxa2 and P-gp. MCF-7/ADR is an MDR human breast cancer cell line with high migration and invasion abilities. The knockdown of P-gp notably impaired the migration and invasion abilities of the tumor cells. The interaction of Anxa2 with P-pg may play an important role in the enhanced invasiveness of MDR human breast cancer cells

The diagnostic application of Ga-67 scintigraphy in primary lung cancer, hepatoma and abdominal abscess

International Nuclear Information System (INIS)

Oshiumi, Yoshihiko

1983-01-01

It is difficult to detect tumor lesions by 67 Gascintigraphy, though it is named as a tumor scintigraphy. Recently, 67 Ga-scintigraphy is well used in the detection of inflammatic lesions. This paper is to discuss the detectability of lesions and diagnostic limitation on operability by 67 Ga-scintigraphy to primary lung cancer, minute hepatoma and abdominal absccess. Primary lung cancer: In detecting metastatic hilar lymph nodes, the sensitivity is 54%, and the specificity is 78%. In detecting metastatic mediastinal lymph nodes, the sensitivity is 32% and the specificity is 89%. Minute hepatoma : The detectability depended on the size of the lesion. It is hard to detect lesions with under 2 cm by 67 Ga-scintigraphy. Abdominal abscess : The sensitivity is 88%, and the specificity is 92%. (author)

Effect of fractionated radiation on multidrug resistance in human ovarian cancer

International Nuclear Information System (INIS)

Kong Dejuan; Liu Xiaodong; Liang Bing; Jia Lili; Ma Shumei

2012-01-01

Objective: To investigate the effect of different subtypes of fractionated doses on multidrug resistance in ovarian cancer cells. Methods: The human ovarian cancer cell lines SKOV3 and its drug-resistant subtype SKVCR were divided into four groups i.e., sham-irradiated, single dose (10 Gy), fractionated dose (2 Gy × 5) and multi-fractionated dose (1 Gy × 2 × 5). Cell sensitivity to vincristine (VCR), etoposide (VP-16), pirarubicin (THP) and cisplatin (DDP) was measured by MTT assay. Western blot was applied to detect the expression of P-gp after irradiation. Results: The doubling time of SKVCR was about 1.8-fold of that of SKOV3 cells. P-gp was expressed in SKVCR but not in SKOV3. IC 50 values of SKVCR were higher than those of SKOV3. To SKOV3 cells, single dose irradiation decreased cell sensitivity to THP and DDP and fractionated irradiation decreased cell sensitivity to VCR, THP and VP-16. Multi-fractionated irradiation decreased cell sensitivity to VP-16. In SKVCR cells, all these irradiation treatments increased cell sensitivity to VCR and VP-16 but not to DDP. In addition, single and fractionated irradiation decreased P-gp expression in SKVCR cells. Conclusions: Single, fractionated and multi-fractionated radiation induced chemotherapy resistance in SKOV3 cells, while reversed drug resistance to VCR and VP-16 in SKVCR cells. (authors)

Genotoxic potential of montmorillonite clay mineral and alteration in the expression of genes involved in toxicity mechanisms in the human hepatoma cell line HepG2.

Science.gov (United States)

Maisanaba, Sara; Hercog, Klara; Filipic, Metka; Jos, Ángeles; Zegura, Bojana

2016-03-05

Montmorillonite, also known as Cloisite(®)Na(+) (CNa(+)), is a natural clay with a wide range of well-documented and novel applications, such as pharmaceutical products or food packaging. Although considered a low toxic product, the expected increased exposure to CNa(+) arises concern on the potential consequences on human and environmental health especially as its genotoxicity has scarcely been investigated so far. Thus, we investigated, for the first time, the influence of non-cytotoxic concentrations of CNa(+) (15.65, 31.25 and 62.5 μg/mL) on genomic instability of human hepatoma cell line (HepG2) by determining the formation of micronuclei (MNi), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) with the Cytokinesis block micronucleus cytome assay. Further on we studied the influence of CNa(+) on the expression of several genes involved in toxicity mechanisms using the real-time quantitative PCR. The results showed that CNa(+) increased the number of MNi, while the numbers of NBUDs and NPBs were not affected. In addition it deregulated genes in all the groups studied, mainly after longer time of exposure. These findings provide the evidence that CNa(+) is potentially genotoxic. Therefore further studies that will elucidate the molecular mechanisms involved in toxic activity of CNa(+) are needed for hazard identification and human safety assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

Altered membrane permeability in multidrug resistant Escherichia ...

African Journals Online (AJOL)

PRECIOUS

2009-11-02

Nov 2, 2009 ... involvement during the transport of β - lactams in multidrug resistant Escherichia coli isolated from extra-intestinal infections. Also, the ... lactam resistance in multidrug resistant E. coli in ESBL and non-ESBL isolates. .... and decreased susceptibility to carbapenems, particularly ertapenem (Perez et al.,.

Antioxidative and apoptotic properties of polyphenolic extracts from edible part of artichoke (Cynara scolymus L.) on cultured rat hepatocytes and on human hepatoma cells.

Science.gov (United States)

Miccadei, Stefania; Di Venere, Donato; Cardinali, Angela; Romano, Ferdinando; Durazzo, Alessandra; Foddai, Maria Stella; Fraioli, Rocco; Mobarhan, Sohrab; Maiani, Giuseppe

2008-01-01

Cultured rat hepatocytes and human hepatoma HepG2 cells were used to evaluate the hepatoprotective properties of polyphenolic extracts from the edible part of artichoke (AE). The hepatocytes were exposed to H2O2generated in situ by glucose oxidase and were treated with either AE, or pure chlorogenic acid (ChA) or with the well known antioxidant, N, N'-diphenyl-p-phenilenediamine (DPPD). Addition of glucose oxidase to the culture medium caused depletion of intracellular glutathione (GSH) content, accumulation of malondialdehyde (MDA) in the cultures, as a lipid peroxidation indicator, and cell death. These results demonstrated that AE protected cells from the oxidative stress caused by glucose oxidase, comparable to DPPD. Furthermore, AE, as well as ChA, prevented the loss of total GSH and the accumulation of MDA. Treatment of HepG2 cells for 24 h with AE reduced cell viability in a dose-dependent manner, however, ChA had no prominent effects on the cell death rate. Similarly, AE rather than ChA induced apoptosis, measured by flow cytometric analysis of annexin and by activation of caspase-3, in HepG2 cells. Our findings indicate that AE had a marked antioxidative potential that protects hepatocytes from an oxidative stress. Furthermore, AE reduced cell viability and had an apoptotic activity on a human liver cancer cell line.

Hydrogen sulfide (H{sub 2}S)/cystathionine γ-lyase (CSE) pathway contributes to the proliferation of hepatoma cells

Energy Technology Data Exchange (ETDEWEB)

Pan, Yan; Ye, Shuang; Yuan, Dexiao; Zhang, Jianghong; Bai, Yang; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

2014-05-15

Highlights: • Inhibition of H{sub 2}S/CSE pathway strongly stimulates cellular apoptosis. • Inhibition of H{sub 2}S/CSE pathway suppresses cell growth by blocking EGFR pathway. • H{sub 2}S/CSE pathway is critical for maintaining the proliferation of hepatoma cells. - Abstract: Hydrogen sulfide (H{sub 2}S)/cystathionine γ-lyase (CSE) pathway has been demonstrated to play vital roles in physiology and pathophysiology. However, its role in tumor cell proliferation remains largely unclear. Here we found that CSE over-expressed in hepatoma HepG2 and PLC/PRF/5 cells. Inhibition of endogenous H{sub 2}S/CSE pathway drastically decreased the proliferation of HepG2 and PLC/PRF/5 cells, and it also enhanced ROS production and mitochondrial disruption, pronounced DNA damage and increased apoptosis. Moreover, this increase of apoptosis was associated with the activation of p53 and p21 accompanied by a decreased ratio of Bcl-2/Bax and up-regulation of phosphorylated c-Jun N-terminal kinase (JNK) and caspase-3 activity. In addition, the negative regulation of cell proliferation by inhibition of H{sub 2}S/CSE system correlated with the blockage of cell mitogenic and survival signal transduction of epidermal growth factor receptor (EGFR) via down-regulating the extracellular-signal-regulated kinase 1/2 (ERK1/2) activation. These results demonstrate that H{sub 2}S/CSE and its downstream pathway contribute to the proliferation of hepatoma cells, and inhibition of this pathway strongly suppress the excessive growth of hepatoma cells by stimulating mitochondrial apoptosis and suppressing cell growth signal transduction.

Crystal structure of the Neisseria gonorrhoeae MtrD inner membrane multidrug efflux pump.

Directory of Open Access Journals (Sweden)

Jani Reddy Bolla

Full Text Available Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually-transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. The MtrCDE tripartite multidrug efflux pump, belonging to the hydrophobic and amphiphilic efflux resistance-nodulation-cell division (HAE-RND family, spans both the inner and outer membranes of N. gonorrhoeae and confers resistance to a variety of antibiotics and toxic compounds. We here report the crystal structure of the inner membrane MtrD multidrug efflux pump, which reveals a novel structural feature that is not found in other RND efflux pumps.

Bacterial multidrug efflux pumps: mechanisms, physiology and pharmacological exploitations.

Science.gov (United States)

Sun, Jingjing; Deng, Ziqing; Yan, Aixin

2014-10-17

Multidrug resistance (MDR) refers to the capability of bacterial pathogens to withstand lethal doses of structurally diverse drugs which are capable of eradicating non-resistant strains. MDR has been identified as a major threat to the public health of human being by the World Health Organization (WHO). Among the four general mechanisms that cause antibiotic resistance including target alteration, drug inactivation, decreased permeability and increased efflux, drug extrusion by the multidrug efflux pumps serves as an important mechanism of MDR. Efflux pumps not only can expel a broad range of antibiotics owing to their poly-substrate specificity, but also drive the acquisition of additional resistance mechanisms by lowering intracellular antibiotic concentration and promoting mutation accumulation. Over-expression of multidrug efflux pumps have been increasingly found to be associated with clinically relevant drug resistance. On the other hand, accumulating evidence has suggested that efflux pumps also have physiological functions in bacteria and their expression is subject tight regulation in response to various of environmental and physiological signals. A comprehensive understanding of the mechanisms of drug extrusion, and regulation and physiological functions of efflux pumps is essential for the development of anti-resistance interventions. In this review, we summarize the development of these research areas in the recent decades and present the pharmacological exploitation of efflux pump inhibitors as a promising anti-drug resistance intervention. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Multidrug efflux pumps at the crossroad between antibiotic resistance and bacterial virulence

Directory of Open Access Journals (Sweden)

Manuel Alcalde-Rico

2016-09-01

Full Text Available Multidrug efflux pumps can be involved in bacterial resistance to antibiotics at different levels. Some efflux pumps are constitutively expressed at low levels and contribute to intrinsic resistance. In addition, their overexpression may allow higher levels of resistance. This overexpression can be transient, in the presence of an effector (phenotypic resistance, or constitutive when mutants in the regulatory elements of the expression of efflux pumps are selected (acquired resistance. Efflux pumps are present in all cells, from human to bacteria and are highly conserved, which indicates that they are ancient elements in the evolution of different organisms. Consequently, it has been suggested that, besides antibiotic resistance, bacterial multidrug efflux pumps would likely contribute to other relevant process of the microbial physiology. In the current article, we discuss some specific examples of the role that efflux pumps may have in the bacterial virulence of animals' and plants' pathogens, including the processes of intercellular communication. Based in these evidences, we propose that efflux pumps are at the crossroad between resistance and virulence of bacterial pathogens. Consequently, the comprehensive study of multidrug efflux pumps requires addressing these functions, which are of relevance for the bacterial-host interactions during infection.

Multidrug Efflux Pumps at the Crossroad between Antibiotic Resistance and Bacterial Virulence.

Science.gov (United States)

Alcalde-Rico, Manuel; Hernando-Amado, Sara; Blanco, Paula; Martínez, José L

2016-01-01

Multidrug efflux pumps can be involved in bacterial resistance to antibiotics at different levels. Some efflux pumps are constitutively expressed at low levels and contribute to intrinsic resistance. In addition, their overexpression may allow higher levels of resistance. This overexpression can be transient, in the presence of an effector (phenotypic resistance), or constitutive when mutants in the regulatory elements of the expression of efflux pumps are selected (acquired resistance). Efflux pumps are present in all cells, from human to bacteria and are highly conserved, which indicates that they are ancient elements in the evolution of different organisms. Consequently, it has been suggested that, besides antibiotic resistance, bacterial multidrug efflux pumps would likely contribute to other relevant processes of the microbial physiology. In the current article, we discuss some specific examples of the role that efflux pumps may have in the bacterial virulence of animals' and plants' pathogens, including the processes of intercellular communication. Based in these evidences, we propose that efflux pumps are at the crossroad between resistance and virulence of bacterial pathogens. Consequently, the comprehensive study of multidrug efflux pumps requires addressing these functions, which are of relevance for the bacterial-host interactions during infection.

Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1

Science.gov (United States)

Kim, Hak-Bong; Lee, Su-Hoon; Um, Jee-Hyun; Oh, Won Keun; Kim, Dong-Wan; Kang, Chi-Dug; Kim, Sun-Hee

2015-01-01

The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp. PMID:26416354

Multidrug Resistance in Infants and Children

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Gian Maria Pacifici

2018-02-01

Full Text Available Bacterial infections may cause disease and death. Infants and children are often subject to bacterial infections. Antimicrobials kill bacteria protecting the infected patients andreducing the risk of morbidity and mortality caused by bacteria. The antibiotics may lose their antibacterial activity when they become resistant to a bacteria. The resistance to different antibiotics in a bacteria is named multidrug-resistance. Gram-negative bacilli, especially Escherichia coli, Klebsiella, Enterobacter, Salmonella, Shigella, Pseudomonas, Streptococcus, and Haemophilus influenzae type b, may become resistant. Amikacin ampicillin, amoxicillin, amoxiclav, cefuroxime, cefotaxime, ceftazidime, cefoperazone tetracycline, chloramphenicol, ciprofloxacin, and gentamicin may cause bacterial-resistance. Resistance to bacteria for several pathogens makes complications in the treatment of infections caused by them. Salmonella strains may become resistant to ampicillin, cephalotin, ceftriaxone, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline. Shigella strains may become resistant to ampicillin, cotrimoxazole, chloramphenicol, and streptomycin. Multidrug-resistance of Streptococcus pneumoniae may be due to β-lactams, macrolides, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. Multidrug-resistance of Pseudomonas aeruginosa may become resistant to β-lactams, chloramphenicol, trimethoprim-sulfamethoxazole, and tetracycline. The antibacterial activity against Haemophilus strains may occur with ampicillin, sulbactam-ampicillin, trimethoprim-sulfamethoxazole, gentamicin, chloramphenicol, and ciprofloxacin. Multidrug-resistance of the Klebsiella species may be due with ampicillin, cefotaxime, cefuroxime, co-amxilav, mezlocillin, chloramphenicol, gentamicin, and ceftazidime. Multidrug-resistance of Escherichia coli may be caused by ampicillin, cotrimoxazole, chloramphenicol, ceftriaxone, and ceftazidime. Vibrio

Relationship Between Substance Abuse and Multidrug-Resistant Tuberculosis

Directory of Open Access Journals (Sweden)

Sadya Afroz

2012-07-01

Full Text Available This case control study was conducted between January to June 2010 to determine the relationship between substance abuse and multidrug- resistant tuberculosis. A total of 73 cases were selected purposively, from culture- positive multidrug- resistant tuberculosis patients admitted in the National Institute of Diseases of the Chest and Hospital, Dhaka and compared with 81 un-matched controls, recruited from the cured patients of pulmonary tuberculosis who attended several DOTS centers of ‘Nagar Shastho Kendra’ under Urban Primary Health Care Project in Dhaka city. Data were collected by face to face interview and documents’ review, using a pre- tested structured questionnaire and a checklist. Multidrug- resistance was found to be associated with smoking status (χ2 = 11.76; p = 0.01 and panmasala use (χ2 = 8.28; p = 0.004. The study also revealed that alcohol consumption and other substance abuse such as jarda, sadapata, gul, snuff, heroine, cannabis, injectable drugs was not associated with the development of multidrug- resistant tuberculosis. Relationship between substance abuse and multidrug- resistant tuberculosis are more or less similar in the developing countries. Bangladesh is not out of this trend. The present study revealed the same fact, which warrants actions targeting specific factors. Further study is recommended to assess the magnitude and these factors related to the development of multidrug- resistant tuberculosis in different settings in our country. Ibrahim Med. Coll. J. 2012; 6(2: 50-54

Genotoxicity assessment of membrane concentrates of landfill leachate treated with Fenton reagent and UV-Fenton reagent using human hepatoma cell line

Energy Technology Data Exchange (ETDEWEB)

Wang, Guifang [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Lu, Gang [Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation of Guangdong Higher Education Institutes, Department of Environmental Engineering, Jinan University, Guangzhou 510632 (China); Yin, Pinghe, E-mail: tyinph@jnu.edu.cn [Research Center of Analysis and Test, Jinan University, Guangzhou 510632 (China); Zhao, Ling, E-mail: zhaoling@jnu.edu.cn [Key Laboratory of Water/Soil Toxic Pollutants Control and Bioremediation of Guangdong Higher Education Institutes, Department of Environmental Engineering, Jinan University, Guangzhou 510632 (China); Jimmy Yu, Qiming [Griffith School of Engineering, Griffith University, Nathan Campus, Brisbane, Queensland 4111 (Australia)

2016-04-15

Highlights: • Membrane concentrates have a threat to human health and environment. • Untreated membrane concentrates induces cytotoxic and genotoxic to HepG2 cells. • Both methods were effective method for degradation of BPA and NP in concentrates. • Both methods were efficient in reducing genotoxic effects of concentrates. • UV-Fenton reagent had higher removal efficiency and provides toxicological safety. - Abstract: Membrane concentrates of landfill leachates contain organic and inorganic contaminants that could be highly toxic and carcinogenic. In this paper, the genotoxicity of membrane concentrates before and after Fenton and UV-Fenton reagent was assessed. The cytotoxicity and genotoxicity was determined by using the methods of methyltetrazolium (MTT), cytokinesis-block micronucleus (CBMN) and comet assay in human hepatoma cells. MTT assay showed a cytotoxicity of 75% after 24 h of exposure to the highest tested concentration of untreated concentrates, and no cytotoxocity for UV-Fenton and Fenton treated concentrates. Both CBMN and comet assays showed increased levels of genotoxicity in cells exposed to untreated concentrates, compared to those occurred in cells exposed to UV-Fenton and Fenton reagent treated concentrates. There was no significant difference between negative control and UV-Fenton treated concentrates for micronucleus and comet assay parameters. UV-Fenton and Fenton treatment, especially the former, were effective methods for degradation of bisphenol A and nonylphenol in concentrates. These findings showed UV-Fenton and Fenton reaction were effective methods for treatment of such complex concentrates, UV-Fenton reagent provided toxicological safety of the treated effluent, and the genotoxicity assays were found to be feasible tools for assessment of toxicity risks of complex concentrates.

Genotoxicity assessment of membrane concentrates of landfill leachate treated with Fenton reagent and UV-Fenton reagent using human hepatoma cell line

International Nuclear Information System (INIS)

Wang, Guifang; Lu, Gang; Yin, Pinghe; Zhao, Ling; Jimmy Yu, Qiming

2016-01-01

Highlights: • Membrane concentrates have a threat to human health and environment. • Untreated membrane concentrates induces cytotoxic and genotoxic to HepG2 cells. • Both methods were effective method for degradation of BPA and NP in concentrates. • Both methods were efficient in reducing genotoxic effects of concentrates. • UV-Fenton reagent had higher removal efficiency and provides toxicological safety. - Abstract: Membrane concentrates of landfill leachates contain organic and inorganic contaminants that could be highly toxic and carcinogenic. In this paper, the genotoxicity of membrane concentrates before and after Fenton and UV-Fenton reagent was assessed. The cytotoxicity and genotoxicity was determined by using the methods of methyltetrazolium (MTT), cytokinesis-block micronucleus (CBMN) and comet assay in human hepatoma cells. MTT assay showed a cytotoxicity of 75% after 24 h of exposure to the highest tested concentration of untreated concentrates, and no cytotoxocity for UV-Fenton and Fenton treated concentrates. Both CBMN and comet assays showed increased levels of genotoxicity in cells exposed to untreated concentrates, compared to those occurred in cells exposed to UV-Fenton and Fenton reagent treated concentrates. There was no significant difference between negative control and UV-Fenton treated concentrates for micronucleus and comet assay parameters. UV-Fenton and Fenton treatment, especially the former, were effective methods for degradation of bisphenol A and nonylphenol in concentrates. These findings showed UV-Fenton and Fenton reaction were effective methods for treatment of such complex concentrates, UV-Fenton reagent provided toxicological safety of the treated effluent, and the genotoxicity assays were found to be feasible tools for assessment of toxicity risks of complex concentrates.

Molecular characterization of multidrug-resistant Shigella spp. of food origin.

Science.gov (United States)

Ahmed, Ashraf M; Shimamoto, Tadashi

2015-02-02

Shigella spp. are the causative agents of food-borne shigellosis, an acute enteric infection. The emergence of multidrug-resistant clinical isolates of Shigella presents an increasing challenge for clinicians in the treatment of shigellosis. Several studies worldwide have characterized the molecular basis of antibiotic resistance in clinical Shigella isolates of human origin, however, to date, no such characterization has been reported for Shigella spp. of food origin. In this study, we characterized the genetic basis of multidrug resistance in Shigella spp. isolated from 1600 food samples (800 meat products and 800 dairy products) collected from different street venders, butchers, retail markets, and slaughterhouses in Egypt. Twenty-four out of 27 Shigella isolates (88.9%) showed multidrug resistance phenotypes to at least three classes of antimicrobials. The multidrug-resistant Shigella spp. were as follows: Shigella flexneri (66.7%), Shigella sonnei (18.5%), and Shigella dysenteriae (3.7%). The highest resistance was to streptomycin (100.0%), then to kanamycin (95.8%), nalidixic acid (95.8%), tetracycline (95.8%), spectinomycin (93.6%), ampicillin (87.5%), and sulfamethoxazole/trimethoprim (87.5%). PCR and DNA sequencing were used to screen and characterize integrons and antibiotic resistance genes. Our results indicated that 11.1% and 74.1% of isolates were positive for class 1 and class 2 integrons, respectively. Beta-lactamase-encoding genes were identified in 77.8% of isolates, and plasmid-mediated quinolone resistance genes were identified in 44.4% of isolates. These data provide useful information to better understand the molecular basis of antimicrobial resistance in Shigella spp. To the best of our knowledge, this is the first report of the molecular characterization of antibiotic resistance in Shigella spp. isolated from food. Copyright © 2014 Elsevier B.V. All rights reserved.

Whole genome sequencing of multidrug-resistant Salmonella enterica serovar Typhimurium isolated from humans and poultry in Burkina Faso.

Science.gov (United States)

Kagambèga, Assèta; Lienemann, Taru; Frye, Jonathan G; Barro, Nicolas; Haukka, Kaisa

2018-01-01

for all the isolates . The poultry and human isolates were genetically similar showing a potential food safety risk for consumers. Our finding of multidrug-resistant S. Typhimurium ST313 in poultry feces calls for further studies to clarify the potential reservoirs of this emerging pathogen.

Antifolate resistance mediated by the multidrug resistance proteins MRP1 and MRP2

NARCIS (Netherlands)

Hooijberg, J. H.; Broxterman, H. J.; Kool, M.; Assaraf, Y. G.; Peters, G. J.; Noordhuis, P.; Scheper, R. J.; Borst, P.; Pinedo, H. M.; Jansen, G.

1999-01-01

Transfection of multidrug resistance proteins (MRPs) MRP1 and MRP2 in human ovarian carcinoma 2008 cells conferred a marked level of resistance to short-term (1-4 h) exposure to the polyglutamatable antifolates methotrexate (MTX; 21-74-fold), ZD1694 (4-138-fold), and GW1843 (101-156-fold). Evidence

Multidrug-Resistant Tuberculosis

Centers for Disease Control (CDC) Podcasts

In this podcast, Dr. Oeltmann discusses multidrug-resistant tuberculosis. An outbreak occurred in Thailand, which led to 45 cases in the U.S. This serious illness can take up to 2 years to treat. MDR TB is a real threat and a serious condition.

A Taiwanese Propolis Derivative Induces Apoptosis through Inducing Endoplasmic Reticular Stress and Activating Transcription Factor-3 in Human Hepatoma Cells

Directory of Open Access Journals (Sweden)

Fat-Moon Suk

2013-01-01

Full Text Available Activating transcription factor-(ATF- 3, a stress-inducible transcription factor, is rapidly upregulated under various stress conditions and plays an important role in inducing cancer cell apoptosis. NBM-TP-007-GS-002 (GS-002 is a Taiwanese propolin G (PPG derivative. In this study, we examined the antitumor effects of GS-002 in human hepatoma Hep3B and HepG2 cells in vitro. First, we found that GS-002 significantly inhibited cell proliferation and induced cell apoptosis in dose-dependent manners. Several main apoptotic indicators were found in GS-002-treated cells, such as the cleaved forms of caspase-3, caspase-9, and poly(ADP-ribose polymerase (PARP. GS-002 also induced endoplasmic reticular (ER stress as evidenced by increases in ER stress-responsive proteins including glucose-regulated protein 78 (GRP78, growth arrest- and DNA damage-inducible gene 153 (GADD153, phosphorylated eukaryotic initiation factor 2α (eIF2α, phosphorylated protein endoplasmic-reticular-resident kinase (PERK, and ATF-3. The induction of ATF-3 expression was mediated by mitogen-activated protein kinase (MAPK signaling pathways in GS-002-treated cells. Furthermore, we found that GS-002 induced more cell apoptosis in ATF-3-overexpressing cells. These results suggest that the induction of apoptosis by the propolis derivative, GS-002, is partially mediated through ER stress and ATF-3-dependent pathways, and GS-002 has the potential for development as an antitumor drug.

Resistant plasmid profile analysis of multidrug resistant Escherichia ...

African Journals Online (AJOL)

Background: Multi-drug resistant Escherichia coli has become a major threat and cause of many urinary tract infections (UTIs) in Abeokuta, Nigeria. Objectives: This study was carried out to determine the resistant plasmids of multidrug resistant Escherichia coli isolated from (Urinary tract infections)UTIs in Abeokuta.

Saponins isolated from Asparagus induce apoptosis in human hepatoma cell line HepG2 through a mitochondrial-mediated pathway

Science.gov (United States)

Ji, Y.; Ji, C.; Yue, L.; Xu, H.

2012-01-01

Objective Many scientific studies have shown that Asparagus officinalis has an antitumour effect and enhances human immunity, but the active components and the antitumour mechanisms are unclear. We investigated the effects of saponins isolated from Asparagus on proliferation and apoptosis in the human hepatoma cell line HepG2. Methods HepG2 cells were treated with varying concentrations of Asparagus saponins at various times. Using mtt and flow cytometry assays, we evaluated the effects of Asparagus saponins on the growth and apoptosis of HepG2 cells. Transmission electron microscopy was used to observe the morphology of cell apoptosis. Confocal laser scanning microscopy was used to analyze intracellular calcium ion concentration, mitochondrial permeability transition pore (mptp), and mitochondrial membrane potential (mmp). Spectrophotometry was applied to quantify the activity of caspase-9 and caspase-3. Flow cytometry was used to investigate the levels of reactive oxygen species (ros) and pH, and the expressions of Bcl2, Bax, CytC, and caspase-3, in HepG2 cells. Results Asparagus saponins inhibited the growth of HepG2 cells in a dose-dependent manner. The median inhibitory concentration (IC50) was 101.15 mg/L at 72 hours. The apoptosis morphology at 72 hours of treatment was obvious, showing cell protuberance, concentrated cytoplasm, and apoptotic bodies. The apoptotic rates at 72 hours were 30.9%, 51.7%, and 62.1% (for saponin concentrations of 50 mg/L, 100 mg/L, 200 mg/L). Treatment with Asparagus saponins for 24 hours increased the intracellular level of ros and Ca2+, lowered the pH, activated intracellular mptp, and decreased mmp in a dose-dependent manner. Treatment also increased the activity of caspase-9 and caspase-3, downregulated the expression of Bcl2, upregulated the expression of Bax, and induced release of CytC and activation of caspase-3. Conclusions Asparagus saponins induce apoptosis in HepG2 cells through a mitochondrial-mediated and caspase

Epidemiology of multi-drug resistant staphylococci in cats, dogs and people in Switzerland

OpenAIRE

Decristophoris, Paola Maria Aurelia

2011-01-01

Background: The human relationship with cats and dogs has been suggested to be of potential concern to public health because of the possible role of pets as reservoir of antibiotic resistant microorganisms. Here I suggest the “One Health” interdisciplinary approach to be helpful towards the understanding of the role of pets in antibiotic resistance spreading, considering also the socio-emotional context of the human-pet relationship. Methods: I investigated the presence of multi-drug resis...

Diagnostic application of Ga-67 scintigraphy in primary lung cancer, hepatoma and abdominal abscess. On surgical operation

Energy Technology Data Exchange (ETDEWEB)

Oshiumi, Yoshihiko (National Central Hospital of Fukuoka (Japan))

1983-05-01

It is difficult to detect tumor lesions by /sup 67/Ga-scintigraphy, though it is named as a tumor scintigraphy. Recently, /sup 67/Ga-scintigraphy is well used in the detection of inflammatic lesions. This paper is to discuss the detectability of lesions and diagnostic limitation on operability by /sup 67/Ga-scintigraphy to primary lung cancer, minute hepatoma and abdominal abscess. Primary lung cancer: In detecting metastatic hilar lymph nodes, the sensitivity is 54%, and the specificity is 78%. In detecting metastatic mediastinal lymph nodes, the sensitivity is 32% and the specificity is 89%. Minute hepatoma : The detectability depended on the size of the lesion. It is hard to detect lesions with under 2 cm by /sup 67/Ga-scintigraphy. Abdominal abscess : The sensitivity is 88%, and the specificity is 92%.

Synergistic effect of intervention of glypican-3 gene transcription combined with antitumor drugs in inhibiting hepatoma cell proliferation

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YANG Jie

2016-12-01

Full Text Available ObjectiveTo investigate the inhibitory effect of intervention of glypican-3 (GPC3 gene transcription combined with antitumor drugs on hepatoma cell proliferation. MethodsFour types of GPC3-shRNA plasmids were established and transfected into HepG2 hepatoma cells. Quantitative real-time PCR and Western blot were used to measure the mRNA and protein expression of GPC3 to analyze its association with hepatoma cell proliferation and apoptosis. The independent samples t-test was used for comparison of continuous data between any two groups, and a one-way analysis of variance was used for comparison between multiple groups. ResultsAmong these four plasmids, shRNA1 had a transfection efficiency of ＞85% in the transfection of HepG2 cells and a silence efficiency of 89.3% at the mRNA level, and the protein expression of GPC3 was significantly inhibited(P＜0.01）. At 72 hours, the GPC3-shRNA1 co-intervention group had an HepG2 cell inhibition rate of 71.1%, significantly different from that in the negative group (t=18.092, P＜0.001, an inhibition rate of migration of 89.1%, significantly lower than that in the negative group (t=8.326, P＜0.001, and inhibition rates of HepG2 cell movement and invasion of 53.6% and 60.1%, which were significantly different from those in the negative group (t=52.400 and 48.245, both P＜0.001. The GPC3-shRNA1 co-intervention group had a β-catenin mRNA inhibition rate of 46.9% and a Gli1 mRNA upregulation rate of 7.4%, significantly different from those in the negative group (t=30.108 and -3.551, P＜0.001 and P=0.009. At 24 hours, 10 μmol/L sorafenib combined with shRNA1 had an inhibition rate of tumor cells of 52.6% and 100 μmol/L sorafenib combined with shRNA1 had an inhibition rate of tumor cells of 79.5%, which were significantly different from that in the control group (t=23.314 and 50.352, both P＜0.001. The half-maximal inhibitory concentrations of sorafenib, rapamycin, and erlotinib for HepG2 were 4.67±1

Radiation induced bystander effect on hepatoma HepG2 cells under hypoxia condition

International Nuclear Information System (INIS)

Zhang Jianghong; Jin Yizun; Shao Chunlin; Prise KM

2009-01-01

Objective: To investigate radiation induced bystander effect and its mechanism on hepatoma HepG2 cells under hypoxia condition. Methods: Non-irradiated bystander hepatoma cells were co-cultured with irradiated cells or treated with the conditioned medium (CM) from irradiated cells, then micronuclei (MN) were measured for both irradiated cells and bystander cells. Results: The MN yield of irradiated HepG2 cells under hypoxic condition was significantly lower than that under normoxia, the oxygen enhancement ratio of HepG2 cells of MN was 1.6. For both hypoxic and normoxic condition, the MN yield of bystander cells were obviously enhanced to a similar high level after co-culturing with irradiated cells or with CM treatment, and it also correlated with the irradiation dose. When the hypoxic HepG2 cells were treated with either DMSO, a scavenger of reactive oxygen species (ROS), or aminoguanidine, an iNOS inhibitor, the yield of bystander MN was partly diminished, and the reducing rate of DMSO was 42.2%-46.7%, the reducing rate of aminoguanidine was 42% . Conclusion: ROS, NO and their downstream signal factors are involved in the radiation induced bystander effect of hypoxic HepG2 cells. (authors)

Genotoxicity and induction of DNA damage responsive genes by food-borne heterocyclic aromatic amines in human hepatoma HepG2 cells.

Science.gov (United States)

Pezdirc, Marko; Žegura, Bojana; Filipič, Metka

2013-09-01

Heterocyclic aromatic amines (HAAs) are potential human carcinogens formed in well-done meats and fish. The most abundant are 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-Amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-Amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ). HAAs exert genotoxic activity after metabolic transformation by CYP1A enzymes, that is well characterized, however the genomic and intervening responses are not well explored. We have examined cellular and genomic responses of human hepatoma HepG2 cells after 24h exposure to HAAs. Comet assay revealed increase in formation of DNA strand breaks by PhIP, MeIQx and IQ but not 4,8-DiMeIQx, whereas increased formation of micronuclei was not observed. The four HAAs up-regulated expression of genes encoding metabolic enzymes CYP1A1, CYP1A2 and UGT1A1 and expression of TP53 and its downstream regulated genes CDKN1A, GADD45α and BAX. Consistent with the up-regulation of CDKN1A and GADD45α the cell-cycle analysis showed arrest in S-phase by PhIP and IQ, and in G1-phase by 4,8-DiMeIQx and MeIQx. The results indicate that upon exposure to HAAs the cells respond with the cell-cycle arrest, which enables cells to repair the damage or eliminate them by apoptosis. However, elevated expression of BCL2 and down-regulation of BAX may indicate that HAAs could suppress apoptosis meaning higher probability of damaged cells to survive and mutate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multidrug resistance in tumour cells: characterisation of the multidrug resistant cell line K562-Lucena 1

Directory of Open Access Journals (Sweden)

VIVIAN M. RUMJANEK

2001-03-01

Full Text Available Multidrug resistance to chemotherapy is a major obstacle in the treatment of cancer patients. The best characterised mechanism responsible for multidrug resistance involves the expression of the MDR-1 gene product, P-glycoprotein. However, the resistance process is multifactorial. Studies of multidrug resistance mechanisms have relied on the analysis of cancer cell lines that have been selected and present cross-reactivity to a broad range of anticancer agents. This work characterises a multidrug resistant cell line, originally selected for resistance to the Vinca alkaloid vincristine and derived from the human erythroleukaemia cell K562. This cell line, named Lucena 1, overexpresses P-glycoprotein and have its resistance reversed by the chemosensitisers verapamil, trifluoperazine and cyclosporins A, D and G. Furthermore, we demonstrated that methylene blue was capable of partially reversing the resistance in this cell line. On the contrary, the use of 5-fluorouracil increased the resistance of Lucena 1. In addition to chemotherapics, Lucena 1 cells were resistant to ultraviolet A radiation and hydrogen peroxide and failed to mobilise intracellular calcium when thapsigargin was used. Changes in the cytoskeleton of this cell line were also observed.A resistência a múltiplos fármacos é o principal obstáculo no tratamento de pacientes com câncer. O mecanismo responsável pela resistência múltipla mais bem caracterizado envolve a expressão do produto do gene MDR-1, a glicoproteína P. Entretanto, o processo de resistência tem fatores múltiplos. Estudos de mecanismos de resistência m��ltipla a fármacos têm dependido da análise de linhagens celulares tumorais que foram selecionadas e apresentam reatividade cruzada a uma ampla faixa de agentes anti-tumorais. Este trabalho caracteriza uma linhagem celular com múltipla resistência a fármacos, selecionada originalmente pela resistência ao alcalóide de Vinca vincristina e derivado

Role of multidrug resistance protein (MRP) in glutathione S-conjugate transport in mammalian cells

NARCIS (Netherlands)

Müller, M.; de Vries, E. G.; Jansen, P. L.

1996-01-01

The human multidrug resistance protein (MRP), a 190-kDa member of the ABC-protein superfamily, is an ATP-dependent glutathione S-conjugate carrier (GS-X pump) and is present in membranes of many, if not all, cells. Overexpression of MRP in tumor cells contributes to resistance to natural product

Role of multidrug resistance protein (MRP) in glutathione S-conjugate transport in mammalian cells

NARCIS (Netherlands)

Muller, M; deVries, EGE; Jansen, PLM

1996-01-01

The human multidrug resistance protein (MRP), a 190-kDa member of the ABC-protein superfamily, is an ATP-dependent glutathione S-conjugate carrier (GS-X pump) and is present in membranes of many, if not all, cells, Overexpression of MRP in tumor cells contributes to resistance to natural product

Modulation of the DNA repair system and ATR-p53 mediated apoptosis is relevant for tributyltin-induced genotoxic effects in human hepatoma G2 cells.

Science.gov (United States)

Li, Bowen; Sun, Lingbin; Cai, Jiali; Wang, Chonggang; Wang, Mengmeng; Qiu, Huiling; Zuo, Zhenghong

2015-01-01

The toxic effects of tributyltin (TBT) have been extensively documented in several types of cells, but the molecular mechanisms related to the genotoxic effects of TBT have still not been fully elucidated. Our study showed that exposure of human hepatoma G2 cells to 1-4 μmol/L TBT for 3 hr caused severe DNA damage in a concentration-dependent manner. Moreover, the expression levels of key DNA damage sensor genes such as the replication factor C, proliferating cell nuclear antigen and poly (ADP-ribose) polymerase-1 were inhabited in a concentration-dependent manner. We further demonstrated that TBT induced cell apoptosis via the p53-mediated pathway, which was most likely activated by the ataxia telangiectasia mutated and rad-3 related (ATR) protein kinase. The results also showed that cytochrome c, caspase-3, caspase-8, caspase-9, and the B-cell lymphoma 2 were involved in this process. Taken together, we demonstrated for the first time that the inhibition of the DNA repair system might be more responsible for TBT-induced genotoxic effects in cells. Then the generated DNA damage induced by TBT initiated ATR-p53-mediated apoptosis. Copyright © 2014. Published by Elsevier B.V.

Knockdown of HOXA10 reverses the multidrug resistance of human chronic mylogenous leukemia K562/ADM cells by downregulating P-gp and MRP-1.

Science.gov (United States)

Yi, Ying-Jie; Jia, Xiu-Hong; Wang, Jian-Yong; Li, You-Jie; Wang, Hong; Xie, Shu-Yang

2016-05-01

Multidrug resistance (MDR) of leukemia cells is a major obstacle in chemotherapeutic treatment. The high expression and constitutive activation of P-glycoprotein (P-gp) and multidrug resistance protein-1 (MRP-1) have been reported to play a vital role in enhancing cell resistance to anticancer drugs in many tumors. The present study aimed to investigate the reversal of MDR by silencing homeobox A10 (HOXA10) in adriamycin (ADR)-resistant human chronic myelogenous leukemia (CML) K562/ADM cells by modulating the expression of P-gp and MRP-1. K562/ADM cells were stably transfected with HOXA10-targeted short hairpin RNA (shRNA). The results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis showed that the mRNA and protein expression of HOXA10 was markedly suppressed following transfection with a shRNA-containing vector. The sensitivity of the K562/ADM cells to ADR was enhanced by the silencing of HOXA10, due to the increased intracellular accumulation of ADR. The accumulation of ADR induced by the silencing of HOXA10 may be due to the downregulation of P-gp and MRP-1. Western blot analysis revealed that downregulating HOXA10 inhibited the protein expression of P-gp and MRP-1. Taken together, these results suggest that knockdown of HOXA10 combats resistance and that HOXA10 is a potential target for resistant human CML.

Characterization of genetically engineered mouse hepatoma cells with inducible liver functions by overexpression of liver-enriched transcription factors.

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Yamamoto, Hideaki; Tonello, Jane Marie; Sambuichi, Takanori; Kawabe, Yoshinori; Ito, Akira; Kamihira, Masamichi

2018-01-01

New cell sources for the research and therapy of organ failure could significantly alleviate the shortage of donor livers that are available to patients who suffer from liver disease. Liver carcinoma derived cells, or hepatoma cells, are the ideal cells for developing bioartificial liver systems. Such cancerous liver cells are easy to prepare in large quantities and can be maintained over long periods under standard culture conditions, unlike primary hepatocytes. However, hepatoma cells possess only a fraction of the functions of primary hepatocytes. In a previous study, by transducing cells with liver-enriched transcription factors that could be inducibly overexpressed-hepatocyte nuclear factor (HNF)1α, HNF1β, HNF3β [FOXA2], HNF4α, HNF6, CCAAT/enhancer binding protein (C/EBP)α, C/EBPβ and C/EBPγ-we created mouse hepatoma cells with high liver-specific gene expression called the Hepa/8F5 cell line. In the present study, we performed functional and genetic analyses to characterize the Hepa/8F5 cell line. Further, in three-dimensional cultures, the function of these cells improved significantly compared to parental cells. Ultimately, these cells might become a new resource that can be used in basic and applied hepatic research. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Identification of multi-drug resistant Pseudomonas aeruginosa clinical isolates that are highly disruptive to the intestinal epithelial barrier

Directory of Open Access Journals (Sweden)

Shevchenko Olga

2006-06-01

Full Text Available Abstract Background Multi-drug resistant Pseudomonas aeruginosa nosocomial infections are increasingly recognized worldwide. In this study, we focused on the virulence of multi-drug resistant clinical strains P. aeruginosa against the intestinal epithelial barrier, since P. aeruginosa can cause lethal sepsis from within the intestinal tract of critically ill and immuno-compromised patients via mechanisms involving disruption of epithelial barrier function. Methods We screened consecutively isolated multi-drug resistant P. aeruginosa clinical strains for their ability to disrupt the integrity of human cultured intestinal epithelial cells (Caco-2 and correlated these finding to related virulence phenotypes such as adhesiveness, motility, biofilm formation, and cytotoxicity. Results Results demonstrated that the majority of the multi-drug resistant P. aeruginosa clinical strains were attenuated in their ability to disrupt the barrier function of cultured intestinal epithelial cells. Three distinct genotypes were found that displayed an extreme epithelial barrier-disrupting phenotype. These strains were characterized and found to harbor the exoU gene and to display high swimming motility and adhesiveness. Conclusion These data suggest that detailed phenotypic analysis of the behavior of multi-drug resistant P. aeruginosa against the intestinal epithelium has the potential to identify strains most likely to place patients at risk for lethal gut-derived sepsis. Surveillance of colonizing strains of P. aeruginosa in critically ill patients beyond antibiotic sensitivity is warranted.

In vitro infectivity of irradiated Plasmodium berghei sporozoites to cultured hepatoma cells

International Nuclear Information System (INIS)

Sigler, C.I.; Leland, P.; Hollingdale, M.R.

1984-01-01

The invasion of gamma-irradiated Plasmodium berghei sporozoites into cultured hepatoma cells and their transformation into trophozoites was similar to invasion and transformation of non-irradiated sporozoites. However, trophozoites from irradiated sporozoites did not further develop into schizonts, but persisted within the cells for up to 3 days. Sporozoite surface protective antigen was present in trophozoites from irradiated and non-irradiated sporozoites, suggesting that hepatocyte antigen processing may contribute to the induction of anti-malarial immunity

Sphingoid bases from sea cucumber induce apoptosis in human hepatoma HepG2 cells through p-AKT and DR5.

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Hossain, Zakir; Sugawara, Tatsuya; Hirata, Takashi

2013-03-01

Biofunctional marine compounds have recently received substantial attention for their nutraceutical characteristics. In this study, we investigated the apoptosis-inducing effects of sphingoid bases prepared from sea cucumber using human hepatoma HepG2 cells. Apoptotic effects were determined by cell viability assay, DNA fragmentation assay, caspase-3 and caspase-8 activities. The expression levels of apoptosis-inducing death receptor-5 (DR5) and p-AKT were assayed by western blot analysis, and mRNA expression of bax, GADD45 and PPARγ was assayed by quantitative RT-PCR analysis. Sphingoid bases from sea cucumber markedly reduced the cell viability of HepG2 cells. DNA fragmentation indicative of apoptosis was observed in a dose-dependent manner. The expression levels of the apoptosis inducer protein Bax were increased by the sphingoid bases from sea cucumber. GADD45, which plays an important role in apoptosis-inducing pathways, was markedly upregulated by sphingoid bases from sea cucumber. Upregulation of PPARγ mRNA was also observed during apoptosis induced by the sphingoid bases. The expression levels of DR5 and p-AKT proteins were increased and decreased, respectively, as a result of the effects of sphingoid bases from sea cucumber. The results indicate that sphingoid bases from sea cucumber induce apoptosis in HepG2 cells through upregulation of DR5, Bax, GADD45 and PPARγ and downregulation of p-AKT. Our results show for the first time the functional properties of marine sphingoid bases as inducers of apoptosis in HepG2 cells.

Multidrug resistance in enteric and other gram-negative bacteria.

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George, A M

1996-05-15

In Gram-negative bacteria, multidrug resistance is a term that is used to describe mechanisms of resistance by chromosomal genes that are activated by induction or mutation caused by the stress of exposure to antibiotics in natural and clinical environments. Unlike plasmid-borne resistance genes, there is no alteration or degradation of drugs or need for genetic transfer. Exposure to a single drug leads to cross-resistance to many other structurally and functionally unrelated drugs. The only mechanism identified for multidrug resistance in bacteria is drug efflux by membrane transporters, even though many of these transporters remain to be identified. The enteric bacteria exhibit mostly complex multidrug resistance systems which are often regulated by operons or regulons. The purpose of this review is to survey molecular mechanisms of multidrug resistance in enteric and other Gram-negative bacteria, and to speculate on the origins and natural physiological functions of the genes involved.

Inhibiting fungal multidrug resistance by disrupting an activator-Mediator interaction.

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Nishikawa, Joy L; Boeszoermenyi, Andras; Vale-Silva, Luis A; Torelli, Riccardo; Posteraro, Brunella; Sohn, Yoo-Jin; Ji, Fei; Gelev, Vladimir; Sanglard, Dominique; Sanguinetti, Maurizio; Sadreyev, Ruslan I; Mukherjee, Goutam; Bhyravabhotla, Jayaram; Buhrlage, Sara J; Gray, Nathanael S; Wagner, Gerhard; Näär, Anders M; Arthanari, Haribabu

2016-02-25

Eukaryotic transcription activators stimulate the expression of specific sets of target genes through recruitment of co-activators such as the RNA polymerase II-interacting Mediator complex. Aberrant function of transcription activators has been implicated in several diseases. However, therapeutic targeting efforts have been hampered by a lack of detailed molecular knowledge of the mechanisms of gene activation by disease-associated transcription activators. We previously identified an activator-targeted three-helix bundle KIX domain in the human MED15 Mediator subunit that is structurally conserved in Gal11/Med15 Mediator subunits in fungi. The Gal11/Med15 KIX domain engages pleiotropic drug resistance transcription factor (Pdr1) orthologues, which are key regulators of the multidrug resistance pathway in Saccharomyces cerevisiae and in the clinically important human pathogen Candida glabrata. The prevalence of C. glabrata is rising, partly owing to its low intrinsic susceptibility to azoles, the most widely used antifungal agent. Drug-resistant clinical isolates of C. glabrata most commonly contain point mutations in Pdr1 that render it constitutively active, suggesting that this transcriptional activation pathway represents a linchpin in C. glabrata multidrug resistance. Here we perform sequential biochemical and in vivo high-throughput screens to identify small-molecule inhibitors of the interaction of the C. glabrata Pdr1 activation domain with the C. glabrata Gal11A KIX domain. The lead compound (iKIX1) inhibits Pdr1-dependent gene activation and re-sensitizes drug-resistant C. glabrata to azole antifungals in vitro and in animal models for disseminated and urinary tract C. glabrata infection. Determining the NMR structure of the C. glabrata Gal11A KIX domain provides a detailed understanding of the molecular mechanism of Pdr1 gene activation and multidrug resistance inhibition by iKIX1. We have demonstrated the feasibility of small-molecule targeting of a

Up-regulation of ALG-2 in hepatomas and lung cancer tissue

DEFF Research Database (Denmark)

la Cour, Jonas Marstrand; Mollerup, Jens; Winding, Pernille

2003-01-01

, a result confirmed by immunohistochemical analysis. Staining of four different lung cancer tissue microarrays including specimens of 263 patients showed that ALG-2 is mainly localized to epithelial cells and significantly up-regulated in small-cell lung cancers and in non-small-cell lung cancers. Our...... using Western blot analysis and immunohistochemistry. Western blot analysis of 15 different adult mouse tissues demonstrated that ALG-2 is ubiquitously expressed. We found that ALG-2 was more than threefold overexpressed in rat liver hepatoma compared to normal rat liver using Western blot analysis...

Magnetic targeting of iron-oxide-labeled fluorescent hepatoma cells to the liver

International Nuclear Information System (INIS)

Luciani, Alain; Wilhelm, Claire; Gazeau, Florence; Bruneval, Patrick; Cunin, Patrick; Autret, Gwennhael; Clement, Olivier; Rahmouni, Alain

2009-01-01

The purpose of this study was to determine whether an external magnet field can induce preferential trafficking of magnetically labeled Huh7 hepatoma cells to the liver following liver cell transplantation. Huh7 hepatoma cells were labeled with anionic magnetic nanoparticles (AMNP) and tagged with a fluorescent membrane marker (PKH67). Iron-uptake was measured by magnetophoresis. Twenty C57Bl6 mice received an intrasplenic injection of 2 x 10 6 labeled cells. An external magnet (0.29 T; 25 T/m) was placed over the liver of 13 randomly selected animals (magnet group), while the remaining 7 animals served as controls. MRI (1.5 T) and confocal fluorescence microscopy (CFM) were performed 10 days post-transplantation. The presence and location of labeled cells within the livers were compared in the magnet group and controls, and confronted with histological analysis representing the standard of reference. Mean iron content per cell was 6 pg. Based on histology, labeled cells were more frequently present within recipient livers in the magnet group (p < 0.01) where their distribution was preferentially peri-vascular (p<0.05). MRI and CFM gave similar results for the overall detection of transplanted cells (kappa=0.828) and for the identification of peri-vascular cells (kappa=0.78). Application of an external magnet can modify the trafficking of transplanted cells, especially by promoting the formation of perivascular aggregates. (orig.)

Uptake of 153Sm-DTPA-bis-biotin and 99mTc-DTPA-bis-biotin in rat as-30D-hepatoma cells

International Nuclear Information System (INIS)

Correa-Gonzalez, Luis; Arteaga de Murphy, Consuelo; Ferro-Flores, Guillermina; Pedraza-Lopez, Martha; Murphy-Stack, Eduardo; Mino-Leon, Dolores; Perez-Villasenor, Graciela; Diaz-Torres, Yaneth; Munoz-Olvera, Rodrigo

2003-01-01

Labeled biotin has been used mainly for pretargeted therapy, an approach for increasing the amount of radioactivity delivered to a cancer cell. The aim of this investigation was to prepare 153 Sm-DTPA-bis-biotin and 99m Tc-DTPA-bis-biotin in order to study their in vitro and in vivo uptake in rat AS-30D hepatoma cells found in ascites and in implanted tumor. DTPA-bis-biotin (pH 8) was 153 Sm labeled with 153 SmCl 3 and 99m Tc-DTPA-bis-biotin was prepared via SnCl 2 reduction. Radiochemical purity was >98% in both cases. AS-30D hepatoma cells were obtained from ascites of a rat with hepatoma and were propagated in the peritoneum cavity of normal rats. In vitro ascites cell 153 Sm-DTPA-bis-biotin uptake was compared with 153 SmCl 3 cell uptake. The ratio cell 153 Sm-DTPA-bis-biotin/ 153 SmCl 3 was 39.6 and when avidin was added it increased to 50. The ratio 99m Tc-DTPA-bis-biotin/TcO 4 Na was 8.7. Concentration of 153 Sm-DTPA-bis-biotin in tumor 2, 3 and 24 h after administration, was 5, 15 and 3 times higher than in normal muscle (T/nT). Biodistribution in a 0.083-24 h time period showed that 153 Sm-DTPA-bis-biotin was taken up only by ascites tumor cells and hepatoma cells. Two and 3 h ratio ascites/liver (As/Lv) was 6.4 and 6.0. For 99m Tc-DTPA-bis-biotin 2 and 3 h T/nT was 15.7 and 4.7 and 2 h As/Lv was 1.4. In conclusion, both radiopharmaceuticals show high uptake in rat AS-30D hepatoma cells in ascites and in implanted tumor. Since lung, thyroid, kidney, liver or pancreas carcinomas are ascites producing cancers 153 Sm-DTPA-bis-biotin would be an adequate therapeutic radiopharmaceutical for these patients whose life quality would be enhanced with control of ascites, and a reduction of the primary tumor and its metastases

Double Standards in Global Health: Medicine, Human Rights Law and Multidrug-Resistant TB Treatment Policy.

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Nicholson, Thomas; Admay, Catherine; Shakow, Aaron; Keshavjee, Salmaan

2016-06-01

The human rights arguments that underpinned the fight against HIV over the last three decades were poised, but ultimately failed, to provide a similar foundation for success against multidrug-resistant TB (MDR-TB) and other diseases of the poor. With more than 1.5 million deaths since 2000 attributed to strains of MDR-TB, and with half a million new, and mostly untreated, MDR-TB cases in the world each year, the stakes could not be higher. The World Health Organization (WHO), whose mandate is to champion the attainment by all peoples of the highest possible level of health, recommended unsound medical treatment for MDR-TB patients in resource-poor settings from 1993-2002. Citing cost considerations, WHO did not recommend the available standard of care that had been successfully used to contain and defeat MDR-TB in rich countries. By acting as a strategic gatekeeper in its technical advisory role to donor agencies and countries, it also facilitated the global implementation of a double standard for TB care in low- and middle-income countries (LMICs), upending important legal and scientific priorities. This raises serious questions about whether the organization violated international human rights standards and those established in its own constitution. While calling for additional analysis and discussion on this topic, the authors propose that policymakers should reject double standards of this kind and instead embrace the challenge of implementing the highest standard of care on a global level.

Caspase-8 acts as a key upstream executor of mitochondria during justicidin A-induced apoptosis in human hepatoma cells.

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Su, Chun-Li; Huang, Lynn L H; Huang, Li-Min; Lee, Jenq-Chang; Lin, Chun-Nan; Won, Shen-Jeu

2006-05-29

Justicia procumbens is a traditional Taiwanese herbal remedy used to treat fever, pain, and cancer. Justicidin A, isolated from Justicia procumbens, has been reported to suppress in vitro growth of several tumor cell lines as well as hepatoma cells. In this study, justicidin A activated caspase-8 to increase tBid, disrupted mitochondrial membrane potential (Delta psi(m)), and caused the release of cytochrome c and Smac/DIABLO in Hep 3B and Hep G2 cells. Justicidin A also reduced Bcl-x(L) and increased Bax and Bak in mitochondria. Caspase-8 inhibitor (Z-IETD) attenuated the justicidin A-induced disruption of Delta psi(m). Growth of Hep 3B implanted in NOD-SCID mice was suppressed significantly by oral justicidin A (20 mg/kg/day). These results indicate that justicidin A-induced apoptosis in these cells proceeds via caspase-8 and is followed by mitochondrial disruption.

Case of double cancer of the liver (hepatoma and cholangioma) caused by accumulation of thorotrast

Energy Technology Data Exchange (ETDEWEB)

Masai, K; Watanabe, T [Yanai-Byoin National Sanatorium, (Japan)

1977-03-01

Fairly many cases of delayed disorders caused by thorotrast have been reported. The authors experienced a case of a 65 year old male who had received an infusion of thorotrast solution at the old army hospital 38 years ago and died from liver cirrhosis and hepatic cancer (double cancer of hepatoma and cholangiocarcinoma). By the biopsy after his death, alpha rays were demonstrated in granules of foreign body in hepatic tissues, and in corporation with its contrast, it was certified that a chain of abnormal shadows mainly seen in the liver and the spleen, on the scout film of the abdomen before death, was caused by thorotrast. From pathological findings in hepatic cancers, hepatoma was recognized in the right lobe and cholangioma, in the left lobe, and there was no pathological relationship between the two cancers. Namely, it was double cancer within the same organ. Case of double cancer in the liver such as this case were thought to be very rare in Japan, and a few literature considerations were also reported.

Molecular dynamics study of lipid bilayers modeling the plasma membranes of mouse hepatocytes and hepatomas.

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Andoh, Yoshimichi; Aoki, Noriyuki; Okazaki, Susumu

2016-02-28

Molecular dynamics (MD) calculations of lipid bilayers modeling the plasma membranes of normal mouse hepatocytes and hepatomas in water have been performed under physiological isothermal-isobaric conditions (310.15 K and 1 atm). The changes in the membrane properties induced by hepatic canceration were investigated and were compared with previous MD calculations included in our previous study of the changes in membrane properties induced by murine thymic canceration. The calculated model membranes for normal hepatocytes and hepatomas comprised 23 and 24 kinds of lipids, respectively. These included phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, sphingomyelin, lysophospholipids, and cholesterol. We referred to previously published experimental values for the mole fraction of the lipids adopted in the present calculations. The calculated structural and dynamic properties of the membranes such as lateral structure, order parameters, lateral self-diffusion constants, and rotational correlation times all showed that hepatic canceration causes plasma membranes to become more ordered laterally and less fluid. Interestingly, this finding contrasts with the less ordered structure and increased fluidity of plasma membranes induced by thymic canceration observed in our previous MD study.

Molecular switch of Cre/loxP for radiation modulated gene therapy on hepatoma

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Y.-J. [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China); Chen, Fu-Du [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China); Institute of Radiological Sciences, Central Taiwan University of Science and Technology, Taiwan (China); Wang, F.H. [National Yang-Ming University Medical School, Taiwan (China); Ke, C.C. [National PET/Cyclotron Center, Taipei Veterans General Hospital, Taiwan (China); Wang, H.-E. [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China); Liu, R.-S. [Institute of Radiological Sciences, National Yang-Ming University, Taiwan (China) and National Yang-Ming University Medical School, Taiwan (China) and National PET/Cyclotron Center, Taipei Veterans General Hospital, Taiwan (China)]. E-mail: maimai5010@yahoo.com.tw

2007-02-01

For the purpose of enhancement of AFP promoter for the use of radiation modulated gene therapy for hepatocellular carcinoma (HCC), we combined hepatitis B virus (HBV) enhancer II with AFP promoter which shows the selectivity to the target cells to control the Cre/loxP system. Different gene constructs, pE4luc, pE4Tk, EIIAPA-Cre, E4CMV-STOP-Tk and chimeric promoters combined with HBV enhancer were constructed and transfected into HepG2, HeLa and NIH-3T3 cell lines. Cell experiments revealed that E4 enhancer responses to radiation best after 60 h irradiation at a dose range of 5-7 Gy in HepG2 stable clone. The EIIAPA promoter provided high specificity to hepatoma and activated the Cre downstream and removed the stop cassette only in hepatoma cells. After removal of the stop cassette, the E4 response to radiation could encode more Tk protein and kill more tumor cells. In summary, the chimeric EIIAPA promoter can stringently control the expression of Cre recombinase only in HCC. The radiation effect of the EIIAPA-Cre and E4CMV-STOP-Tk system shows promising results in terms of cell survival of HCC.

Molecular switch of Cre/loxP for radiation modulated gene therapy on hepatoma

International Nuclear Information System (INIS)

Hsieh, Y.-J.; Chen, Fu-Du; Wang, F.H.; Ke, C.C.; Wang, H.-E.; Liu, R.-S.

2007-01-01

For the purpose of enhancement of AFP promoter for the use of radiation modulated gene therapy for hepatocellular carcinoma (HCC), we combined hepatitis B virus (HBV) enhancer II with AFP promoter which shows the selectivity to the target cells to control the Cre/loxP system. Different gene constructs, pE4luc, pE4Tk, EIIAPA-Cre, E4CMV-STOP-Tk and chimeric promoters combined with HBV enhancer were constructed and transfected into HepG2, HeLa and NIH-3T3 cell lines. Cell experiments revealed that E4 enhancer responses to radiation best after 60 h irradiation at a dose range of 5-7 Gy in HepG2 stable clone. The EIIAPA promoter provided high specificity to hepatoma and activated the Cre downstream and removed the stop cassette only in hepatoma cells. After removal of the stop cassette, the E4 response to radiation could encode more Tk protein and kill more tumor cells. In summary, the chimeric EIIAPA promoter can stringently control the expression of Cre recombinase only in HCC. The radiation effect of the EIIAPA-Cre and E4CMV-STOP-Tk system shows promising results in terms of cell survival of HCC

Multidrug-Resistant Tuberculosis

Centers for Disease Control (CDC) Podcasts

2008-10-28

In this podcast, Dr. Oeltmann discusses multidrug-resistant tuberculosis. An outbreak occurred in Thailand, which led to 45 cases in the U.S. This serious illness can take up to 2 years to treat. MDR TB is a real threat and a serious condition.  Created: 10/28/2008 by Emerging Infectious Diseases.   Date Released: 10/28/2008.

Non-cytotoxic nanomaterials enhance antimicrobial activities of cefmetazole against multidrug-resistant Neisseria gonorrhoeae.

Directory of Open Access Journals (Sweden)

Lan-Hui Li

Full Text Available The emergence and spread of antibiotic-resistant Neisseria gonorrhoeae has led to difficulties in treating patients, and novel strategies to prevent and treat this infection are urgently needed. Here, we examined 21 different nanomaterials for their potential activity against N. gonorrhoeae (ATCC 49226. Silver nanoparticles (Ag NPs, 120 nm showed the greatest potency for reducing N. gonorrhoeae colony formation (MIC: 12.5 µg/ml and possessed the dominant influence on the antibacterial activity with their properties of the nanoparticles within a concentration range that did not induce cytotoxicity in human fibroblasts or epithelial cells. Electron microscopy revealed that the Ag NPs significantly reduced bacterial cell membrane integrity. Furthermore, the use of clinical isolates of multidrug-resistant N. gonorrhoeae showed that combined treatment with 120 nm Ag NPs and cefmetazole produced additive effects. This is the first report to screen the effectiveness of nanomaterials against N. gonorrhoeae, and our results indicate that 120 nm Ag NPs deliver low levels of toxicity to human epithelial cells and could be used as an adjuvant with antibiotic therapy, either for topical use or as a coating for biomaterials, to prevent or treat multidrug-resistant N. gonorrhoeae.

Value of an hepatobiliary imaging agent for diagnosing hepatoma. Example of diethyl-IDA

Energy Technology Data Exchange (ETDEWEB)

Bourguet, P; Estable, P; Herry, J Y

1985-01-01

A comparative study was performed using two hepatic tracers, a Tc 99m labelled colloid and an hepatobiliary agent Tc 99m labelled diethyl-IDA. In some patients with isolated primary hepatocarcinoma the uptake of the hepatobiliary agent was observed but the colloid was not taken up. In the contrary, the hepatobiliary agent has proved to be of limited value for the diagnosis of hepatomas coexisting with cirrhosis and for the detection of secondary hepatocarcinoma.

Vinclozolin, a widely used fungizide, enhanced BaP-induced micronucleus formation in human derived hepatoma cells by increasing CYP1A1 expression.

Science.gov (United States)

Wu, Xin-Jiang; Lu, Wen-qing; Roos, Peter H; Mersch-Sundermann, Volker

2005-10-15

Vinclozolin, a widely used fungicide, can be identified as a residue in numerous vegetable and fruit samples. To get insight in its genetic toxicity, we investigated the genotoxic effect of vinclozolin in the human derived hepatoma cell line HepG2 using the micronucleus (MN) assay. Additionally, to evaluate the co- or anti-mutagenic potency of vinclozolin, we treated HepG2 cells with different concentrations of vinclozolin for 24 h. Subsequently, the cells were exposed to benzo[a]pyrene (BaP) for 1h. Exposure of HepG2 cells to 50-400 microM vinclozolin alone did not cause any induction of micronuclei. However, a pronounced co-mutagenic effect was observed. MN frequencies caused by BaP increased by 30.6%, 52.8% and 65.3% after pretreatment of the cell cultures with 50, 100 and 200 microM vinclozolin, respectively. The highest concentration (400 microM) of vinclozolin tested caused cytotoxicity. Therefore, micronuclei were not considered for that concentration. To clarify the mechanism of cogenotoxicity, we assayed cytochrome P450 1A1 (CYP1A1), which plays a pivotal role in activation of BaP. Cells exposed to vinclozolin led to significant increase of CYP1A1 expression in Western blot. The result suggested that induction of CYP1A1 by vinclozolin account for its enhancing effect on genotoxicity caused by BaP.

Hepatitis B virus X protein promotes interleukin-7 receptor expression via NF-κB and Notch1 pathway to facilitate proliferation and migration of hepatitis B virus-related hepatoma cells

Directory of Open Access Journals (Sweden)

Fanyun Kong

2016-11-01

Full Text Available Abstract Background Interleukin-7 receptor (IL-7R is involved in the abnormal function of solid tumors, but the role and regulatory mechanisms of IL-7R in HBV-related hepatocellular carcinoma (HCC are still unclear. Methods Gene and protein expression levels of IL-7R were examined in hepatoma cells transfected with hepatitis B virus (HBV plasmids and in hepatoma cells transfected with the multifunctional nonstructural protein X (HBX. The expression of HBX and IL-7R was measured by immunohistochemical analysis in HBV-related HCC tissues. The role of NF-κB and Notch1 pathways in HBX-mediated expression of IL-7R in hepatoma cells was examined. Activation of IL-7R downstream of intracellular signaling proteins AKT, JNK, STAT5, and the associated molecules CyclinD1 and matrix metalloproteinase-9 (MMP-9, was assessed in HBX-positive cells with or without treatment with IL-7R short hairpin RNA (shRNA. Additionally, the role of IL-7R in HBX-mediated proliferation and migration of hepatoma cells was investigated. Results The expression of IL-7R was increased in hepatoma cells transfected with HBV plasmids; HBX was responsible for the HBV-mediated upregulation of IL-7R. Compared to adjacent tissues, the expression of HBX and IL-7R was increased in HBV-related HCC tissues. Additionally, the relative expression levels of HBX were associated with IL-7R in HBV-related HCC tissues. The activation of NF-κB pathways and expression of Notch1 were increased in hepatoma cells transfected with HBX, and inhibition of NF-κB and Notch1 pathways significantly decreased HBX-mediated expression of IL-7R. The activation of AKT and JNK and the expression of CyclinD1 and MMP-9 were increased in HBX-positive cells. When cells were treated with IL-7R shRNA, the activation of AKT and JNK, as well as the expression of CyclinD1 and MMP-9, were significantly inhibited. Additionally, IL-7R was responsible for HBX-induced proliferation and migration ability of hepatoma cells

The radiological spectrum of pulmonary multidrug-resistant tuberculosis: in HIV-Negative patients

International Nuclear Information System (INIS)

Zahirifard, S.; Amiri, M.V.; Bakhshayesh Karam, M.; Mirsaeidi, S.M.; Ehsanpour, A.; Masjedi, M.R.

2003-01-01

Background: Multidrug-resistant tuberculosis is a major worldwide health problem. In countries where tuberculosis is of moderate to high prevalence, the issue of Multidrug-resistant tuberculosis carries significant importance. Multidrug-resistant tuberculosis, similar to drug-sensitive tuberculosis, is contagious. Meanwhile its treatment is not only more difficult but also more expensive with lower success rates. Regarding clinical findings, there is no significant difference between Multidrug-resistant tuberculosis and drug-sensitive tuberculosis. Therefore determination of characteristic radiological findings in cases of Multidrug-resistant tuberculosis might be of help in early detection, and hence appropriate management of this disease condition. Objective: To explain the radiological spectrum of pulmonary Multidrug-resistant tuberculosis. Patients and methods: We retrospectively evaluated the radiographic images of 35 patients with clinically-and microbiologically- proven Multidrug-resistant tuberculosis admitted to our tertiary-care tuberculosis unit over a period of 13 months. The latest chest x-ray of all patients and the conventional chest CT scan without contrast of 15 patients were reviewed by three expert radiologists who rendered consensus opinion. Results: Of the 35 patients with imaging studies, 23 (66%) were male and 12 (34%) were female. The mean±SD age of participants was 38.2±17.3 (range: 16-20) years. 33 patients were known as secondary and only 2 had primary Multidrug-resistant tuberculosis. Chest radiography revealed cavitary lesion in 80% pulmonary infiltration in 89% and nodules in 80% of the cases. Pleurisy was the rarest finding observed in only 5 (14%) patients. All of 15 chest CT scans revealed cavitation, 93% of which were bilateral and multiple. Pleural involvement was seen in 93% of patients. Conclusion: Presence of multiple cavities, especially in both lungs, nodular and infiltrative lesions, and pleural effusion are main features

P-glycoprotein binds to ezrin at amino acid residues 149-242 in the FERM domain and plays a key role in the multidrug resistance of human osteosarcoma.

Science.gov (United States)

Brambilla, Daria; Zamboni, Silvia; Federici, Cristina; Lugini, Luana; Lozupone, Francesco; De Milito, Angelo; Cecchetti, Serena; Cianfriglia, Maurizio; Fais, Stefano

2012-06-15

Overexpression of the mdr1 gene encoding P-glycoprotein (Pgp) exerts a major role in reducing the effectiveness of cytotoxic therapy in osteosarcoma. The interaction between actin and Pgp has been shown to be instrumental in the establishment of multidrug resistance (MDR) in human tumor cells. The cytoskeleton linker ezrin exerts a pivotal role in maintaining the functional connection between actin and Pgp. We investigated the role of ezrin in a human multidrug-resistant osteosarcoma cell line overexpressing Pgp and compared it to its counterpart that overexpresses an ezrin deletion mutant. The results showed that Pgp binds at amino acid residues 149-242 of the N-terminal domain of ezrin. The interaction between ezrin and Pgp occurs in the plasma membrane of MDR cells, where they also co-localize with the ganglioside G(M1) located in lipid rafts. The overexpression of the ezrin deletion mutant entirely restored drug susceptibility of osteosarcoma cells, consistent with Pgp dislocation to cytoplasmic compartments and abrogation of G(M1) /Pgp co-localization at the plasma membrane. Our study provides evidence that ezrin exerts a key role in MDR of human osteosarcoma cells through a Pgp-ezrin-actin connection that is instrumental for the permanence of Pgp into plasma membrane lipid rafts. We also show for the first time that Pgp-binding site is localized to amino acid residues 149-242 of the ezrin Band 4.1, Ezrin/Radixin/Moesin (FERM) domain, thus proposing a specific target for future molecular therapy aimed at counteracting MDR in osteosarcoma patients. Copyright © 2011 UICC.

Development of hydroxyapatite-chitosan gel sunscreen combating clinical multidrug-resistant bacteria

Science.gov (United States)

Morsy, Reda; Ali, Sameh S.; El-Shetehy, Mohamed

2017-09-01

The several harmful effects on infected human skin resulting from exposure to the sun's UV radiation generate an interest in the development of a multifunctional hydroxyapatite-chitosan (HAp-chitosan) gel that works as an antibacterial sunscreen agent for skin care. In this work, HAp-chitosan gel was synthesized via coprecipitation method by dissolving chitosan in phosphoric acid and adding HAp. The characteristics of HAp-chitosan composite were investigated by conventional techniques, such as XRD, FTIR, and SEM techniques, while its sunscreen property was investigated by UV-spectroscopy. In addition to the influence of the gel on bacterial cell morphology, the antibacterial activity of HAp-chitosan gel against clinical multidrug resistant skin pathogens, such as Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa has been studied. The results revealed the formation of HAp-chitosan gel having nanosized particles, which confers protection against UV-radiation. The antibacterial activity records showed that chitosan-HAp gel exhibits a significant effect on the growth and ultrastructure of multi-drug resistant bacterial activities. Therefore, the chitosan-HAp gel is promising for skin health care as an antibacterial sunscreen.

Value of an hepatobiliary imaging agent for diagnosing hepatoma. Example of diethyl-IDA

International Nuclear Information System (INIS)

Bourguet, P.; Estable, P.; Herry, J.Y.

1985-01-01

A comparative study was performed using two hepatic tracers, a Tc 99m labelled colloid and an hepatobiliary agent Tc 99m labelled diethyl-IDA. In some patients with isolated primary hepatocarcinoma the uptake of the hepatobiliary agent was observed but the colloid was not taken up. In the contrary, the hepatobiliary agent has proved to be of limited value for the diagnosis of hepatomas coexisting with cirrhosis and for the detection of secondary hepatocarcinoma [fr

Magnetic targeting of iron-oxide-labeled fluorescent hepatoma cells to the liver

Energy Technology Data Exchange (ETDEWEB)

Luciani, Alain [Universite Rene Descartes, Hopital Europeen Georges Pompidou, Laboratoire de Recherche en Imagerie, EA 4062, Paris (France); Imagerie Medicale, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France); Wilhelm, Claire; Gazeau, Florence [Universite Paris Diderot, Batiment Condorcet, Laboratoire Matiere et Systemes Complexes, CNRS-UMR 7057, Paris Cedex (France); Bruneval, Patrick [Anatomopathologie, Hopital Europeen Georges Pompidou, Paris (France); Cunin, Patrick [Unite de Recherche Clinique, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France); Autret, Gwennhael; Clement, Olivier [Universite Rene Descartes, Hopital Europeen Georges Pompidou, Laboratoire de Recherche en Imagerie, EA 4062, Paris (France); Rahmouni, Alain [Imagerie Medicale, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France)

2009-05-15

The purpose of this study was to determine whether an external magnet field can induce preferential trafficking of magnetically labeled Huh7 hepatoma cells to the liver following liver cell transplantation. Huh7 hepatoma cells were labeled with anionic magnetic nanoparticles (AMNP) and tagged with a fluorescent membrane marker (PKH67). Iron-uptake was measured by magnetophoresis. Twenty C57Bl6 mice received an intrasplenic injection of 2 x 10{sup 6} labeled cells. An external magnet (0.29 T; 25 T/m) was placed over the liver of 13 randomly selected animals (magnet group), while the remaining 7 animals served as controls. MRI (1.5 T) and confocal fluorescence microscopy (CFM) were performed 10 days post-transplantation. The presence and location of labeled cells within the livers were compared in the magnet group and controls, and confronted with histological analysis representing the standard of reference. Mean iron content per cell was 6 pg. Based on histology, labeled cells were more frequently present within recipient livers in the magnet group (p < 0.01) where their distribution was preferentially peri-vascular (p<0.05). MRI and CFM gave similar results for the overall detection of transplanted cells (kappa=0.828) and for the identification of peri-vascular cells (kappa=0.78). Application of an external magnet can modify the trafficking of transplanted cells, especially by promoting the formation of perivascular aggregates. (orig.)

Glyco-nanoparticles with sheddable saccharide shells: A unique and potent platform for hepatoma-targeting delivery of anticancer drugs

NARCIS (Netherlands)

Chen, Wei; Zou, Yan; Meng, Fenghua; Cheng, Ru; Deng, Chao; Feijen, Jan; Zhong, Zhiyuan

2014-01-01

Reduction-sensitive shell-sheddable glyco-nanoparticles were designed and developed based on poly(ε-caprolactone)-graft-SS-lactobionic acid (PCL-g-SS-LBA) copolymer for efficient hepatoma-targeting delivery of doxorubicin (DOX). PCL-g-SS-LBA was prepared by ring-opening copolymerization of

A case of double cancer of the liver (hepatoma and cholangioma) caused by accumulation of thorotrast

International Nuclear Information System (INIS)

Masai, Kenji; Watanabe, Tadashi

1977-01-01

Fairly many cases of delayed disorders caused by thorotrast have been reported. The authors experienced a case of 65 year old male who had received an infusion of thorotrast solution at the old army hospital 38 years ago and died for liver cirrhosis and hepatic cancer (double cancer of hepatoma and cholangiocarcinoma). By the biopsy after his death, alpha ray was proved in granules of foreign body in hepatic tissues, and in corporation with its contrast, it was certified that a chain of abnormal shadows mainly seen in the liver and the spleen, on the scout film of the abdomen before death, was caused by thorotrast. From pathological findings in hepatic cancers, hepatoma was recognized in the right lobe and cholangioma, in the left lobe, and there was no pathological relationship between two cancers. Namely, it was double cancer within the same organ. Case of double cancer in the liver such as this case was thought to be very rare in Japan, and a few literature considerations were also reported. (Tsunoda, M.)

Inhibitory effects of α-pinene on hepatoma carcinoma cell proliferation.

Science.gov (United States)

Chen, Wei-Qiang; Xu, Bin; Mao, Jian-Wen; Wei, Feng-Xiang; Li, Ming; Liu, Tao; Jin, Xiao-Bao; Zhang, Li-Rong

2014-01-01

Pine needle oil from crude extract of pine needles has anti-tumor effects, but the effective component is not known. In the present study, compounds from a steam distillation extract of pine needles were isolated and characterized. Alpha-pinene was identified as an active anti-proliferative compound on hepatoma carcinoma BEL-7402 cells using the MTT assay. Further experiments showed that α-pinene inhibited BEL-7402 cells by arresting cell growth in the G2/M phase of the cell cycle, downregulating Cdc25C mRNA and protein expression, and reducing cycle dependence on kinase 1(CDK1) activity. Taken together, these findings indicate that α-pinene may be useful as a potential anti-tumor drug.

Multidrug Efflux Pumps in Staphylococcus aureus: an Update

OpenAIRE

Costa, Sofia Santos; Viveiros, Miguel; Amaral, Leonard; Couto, Isabel

2013-01-01

The emergence of infections caused by multi- or pan-resistant bacteria in the hospital or in the community settings is an increasing health concern. Albeit there is no single resistance mechanism behind multiresistance, multidrug efflux pumps, proteins that cells use to detoxify from noxious compounds, seem to play a key role in the emergence of these multidrug resistant (MDR) bacteria. During the last decades, experimental data has established their contribution to low level resistance to an...

Folate-targeted paclitaxel-conjugated polymeric micelles inhibits pulmonary metastatic hepatoma in experimental murine H22 metastasis models

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Zhang Y

2014-04-01

Full Text Available Yan Zhang,1 Hui Zhang,2 Wenbin Wu,2 Fuhong Zhang,3,4 Shi Liu,3 Rui Wang,3 Yingchun Sun,1 Ti Tong,1 Xiabin Jing3 1Department of Thoracic Surgery, The Second Hospital of Jilin University, Changchun, Jilin, People's Republic of China; 2Department of Thoracic Surgery, Xuzhou Central Hospital, Xuzhou, Jiangsu, People's Republic of China; 3State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, People's Republic of China; 4Department of Otolaryngology, The First Hospital of Lanzhou University, Lanzhou, Gansu, People's Republic of China Abstract: Hepatocellular carcinoma shows low response to most conventional chemotherapies; additionally, extrahepatic metastasis from hepatoma is considered refractory to conventional systemic chemotherapy. Target therapy is a promising strategy for advanced hepatoma; however, targeted accumulation and controlled release of therapeutic agents into the metastatic site is still a great challenge. Folic acid (FA and paclitaxel (PTX containing composite micelles (FA-M[PTX] were prepared by coassembling the FA polymer conjugate and PTX polymer conjugate. The main purpose of this study is to investigate the inhibitory efficacy of FA-M(PTX on the pulmonary metastasis of intravenously injected murine hepatoma 22 (H22 on BALB/c mice models. The lung metastatic burden of H22 were measured and tissues were analyzed by immunohistochemistry and histology (hematoxylin and eosin stain, followed by survival analysis. The results indicated that FA-M(PTX prevented pulmonary metastasis of H22, and the efficacy was stronger than pure PTX and simple PTX-conjugated micelles. In particular, the formation of lung metastasis colonies in mice was evidently inhibited, which was paralleled with the downregulated expression of matrix metalloproteinase-2 and matrix metalloproteinase-9. Furthermore, the mice bearing pulmonary metastatic hepatoma in the FA

Exogenous regucalcin suppresses the growth of human liver cancer HepG2 cells in vitro.

Science.gov (United States)

Yamaguchi, Masayoshi; Murata, Tomiyasu

2018-04-05

Regucalcin, which its gene is localized on the X chromosome, plays a pivotal role as a suppressor protein in signal transduction in various types of cells and tissues. Regucalcin gene expression has been demonstrated to be suppressed in various tumor tissues of animal and human subjects, suggesting a potential role of regucalcin in carcinogenesis. Regucalcin, which is produced from the tissues including liver, is found to be present in the serum of human subjects and animals. This study was undertaken to determine the effects of exogenous regucalcin on the proliferation in cloned human hepatoma HepG2 cells in vitro. Proliferation of HepG2 cells was suppressed after culture with addition of regucalcin (0.01 – 10 nM) into culture medium. Exogenous regucalcin did not reveal apoptotic cell death in HepG2 cells in vitro. Suppressive effects of regucalcin on cell proliferation were not enhanced in the presence of various signaling inhibitors including tumor necrosis factor-α (TNF-α), Bay K 8644, PD98059, staurosporine, worthomannin, 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) or gemcitabine, which were found to suppress the proliferation. In addition, exogenous regucalcin suppressed the formation of colonies of cultured hepatoma cells in vitro. These findings demonstrated that exogenous regucalcin exhibits a suppressive effect on the growth of human hepatoma HepG2 cells, proposing a strategy with the gene therapy for cancer treatment.

Hospital costs of nosocomial multi-drug resistant Pseudomonas aeruginosa acquisition.

Science.gov (United States)

Morales, Eva; Cots, Francesc; Sala, Maria; Comas, Mercè; Belvis, Francesc; Riu, Marta; Salvadó, Margarita; Grau, Santiago; Horcajada, Juan P; Montero, Maria Milagro; Castells, Xavier

2012-05-23

We aimed to assess the hospital economic costs of nosocomial multi-drug resistant Pseudomonas aeruginosa acquisition. A retrospective study of all hospital admissions between January 1, 2005, and December 31, 2006 was carried out in a 420-bed, urban, tertiary-care teaching hospital in Barcelona (Spain). All patients with a first positive clinical culture for P. aeruginosa more than 48 h after admission were included. Patient and hospitalization characteristics were collected from hospital and microbiology laboratory computerized records. According to antibiotic susceptibility, isolates were classified as non-resistant, resistant and multi-drug resistant. Cost estimation was based on a full-costing cost accounting system and on the criteria of clinical Activity-Based Costing methods. Multivariate analyses were performed using generalized linear models of log-transformed costs. Cost estimations were available for 402 nosocomial incident P. aeruginosa positive cultures. Their distribution by antibiotic susceptibility pattern was 37.1% non-resistant, 29.6% resistant and 33.3% multi-drug resistant. The total mean economic cost per admission of patients with multi-drug resistant P. aeruginosa strains was higher than that for non-resistant strains (15,265 vs. 4,933 Euros). In multivariate analysis, resistant and multi-drug resistant strains were independently predictive of an increased hospital total cost in compared with non-resistant strains (the incremental increase in total hospital cost was more than 1.37-fold and 1.77-fold that for non-resistant strains, respectively). P. aeruginosa multi-drug resistance independently predicted higher hospital costs with a more than 70% increase per admission compared with non-resistant strains. Prevention of the nosocomial emergence and spread of antimicrobial resistant microorganisms is essential to limit the strong economic impact.

INVESTIGATION OF HYPOLIPIDEMIC EFFECT OF SESQUITERPENE Γ-LACTONE AHILLIN IN HEPATOMA TISSUE CULTURE (HTC CELLS

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V. V. Ivanov

2014-01-01

Full Text Available Objective. Investigation of hypolipidemic effect of sesquiterpene γ-lactone ahillin in hepatoma tissue culture (HTC cells.Material and methods. In this study we’ve evaluated the effect of γ-lactone sesquiterpene aсhillin and gemfibrozil (comparator drug on the lipid content in the hepatoma tissue culture (HTC cell which were incubated with a fat emulsion lipofundin by fluorescent method with vital dye Nile Redand staining the cells with the dye Oil Red O. The cell viability was investigated using the MTT-test and staining with Trypan blue.Results. Cultivation cells HTC with aсhillin and gemfibrozilat concentrations ranging from 0.5 to1.5 mM and from0.25 mM to0.5 mM, respectively, resulted in dose-dependent decrease of the fluorescence’s intensity Nile Red. It reflects a decrease in lipid content in the cells. At these concentrations the drugs didn’t have cytotoxic effect and the cell viability didn’t change compared to the control culture.An experimental hyperlipidemia in the hepatoma culture cells was induced by adding to the incubation medium a fat emulsion lipofundin at a final concentration 0.05%. The intensity of fluorescence Nile Red in the cells was increased 4 fold (p < 0.05. This result suggests the significant accumulation of lipids in the cell’s cytosol and confirmed by microscopy after staining neutral lipids with the dye Oil Red O. Under these conditions aсhillin and gemfibrozil reduced lipid content in cells and hadthe effect at concentrations of0.5 mM and0.25 mM respectively.Conclusion. In the lipofundin-mediated model of hyperlipidemia the sesquiterpene lactone aсhillin prevents the lipid accumulation in cells. It confirms by decrease of fluorescence Nile Red and reduction lipid drops which were stained with Oil Red O in cytosol. To establish the molecular targets of aсhillin’saction on lipid metabolism in cell culture HTC we need to investigate a gene expression of key enzymes of lipid metabolism.

Homologs of the Acinetobacter baumannii AceI transporter represent a new family of bacterial multidrug efflux systems.

Science.gov (United States)

Hassan, Karl A; Liu, Qi; Henderson, Peter J F; Paulsen, Ian T

2015-02-10

Multidrug efflux systems are a major cause of resistance to antimicrobials in bacteria, including those pathogenic to humans, animals, and plants. These proteins are ubiquitous in these pathogens, and five families of bacterial multidrug efflux systems have been identified to date. By using transcriptomic and biochemical analyses, we recently identified the novel AceI (Acinetobacter chlorhexidine efflux) protein from Acinetobacter baumannii that conferred resistance to the biocide chlorhexidine, via an active efflux mechanism. Proteins homologous to AceI are encoded in the genomes of many other bacterial species and are particularly prominent within proteobacterial lineages. In this study, we expressed 23 homologs of AceI and examined their resistance and/or transport profiles. MIC analyses demonstrated that, like AceI, many of the homologs conferred resistance to chlorhexidine. Many of the AceI homologs conferred resistance to additional biocides, including benzalkonium, dequalinium, proflavine, and acriflavine. We conducted fluorimetric transport assays using the AceI homolog from Vibrio parahaemolyticus and confirmed that resistance to both proflavine and acriflavine was mediated by an active efflux mechanism. These results show that this group of AceI homologs represent a new family of bacterial multidrug efflux pumps, which we have designated the proteobacterial antimicrobial compound efflux (PACE) family of transport proteins. Bacterial multidrug efflux pumps are an important class of resistance determinants that can be found in every bacterial genome sequenced to date. These transport proteins have important protective functions for the bacterial cell but are a significant problem in the clinical setting, since a single efflux system can mediate resistance to many structurally and mechanistically diverse antibiotics and biocides. In this study, we demonstrate that proteins related to the Acinetobacter baumannii AceI transporter are a new class of multidrug

Tailoring Cytotoxicity of Antimicrobial Peptidomimetics with High Activity against Multidrug-Resistant Escherichia coli

DEFF Research Database (Denmark)

Jahnsen, Rasmus D; Sandberg-Schaal, Anne; Vissing, Karina Juul

2014-01-01

Infections with multidrug-resistant pathogens are an increasing concern for public health. Recently, subtypes of peptide-peptoid hybrids were demonstrated to display potent activity against multidrug-resistant Gram-negative bacteria. Here, structural variation of these antibacterial peptidomimetics...... cells. Thus, lead compounds with a high selectivity toward killing of clinically important multidrug-resistant E. coli were identified....

Genotoxic potential of montmorillonite clay mineral and alteration in the expression of genes involved in toxicity mechanisms in the human hepatoma cell line HepG2

Energy Technology Data Exchange (ETDEWEB)

Maisanaba, Sara, E-mail: saramh@us.es [Area of Toxicology, Faculty of Pharmacy, University of Sevilla, Profesor García González no. 2, 41012 Seville (Spain); Hercog, Klara; Filipic, Metka [National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Vecna pot 111, 1000 Ljubljana (Slovenia); Jos, Ángeles [Area of Toxicology, Faculty of Pharmacy, University of Sevilla, Profesor García González no. 2, 41012 Seville (Spain); Zegura, Bojana [National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Vecna pot 111, 1000 Ljubljana (Slovenia)

2016-03-05

Highlights: • Cloisite{sup ®}Na{sup +} has a wide range of well-documented and novel applications. • Cloisite{sup ®}Na{sup +} induces micronucleus, but not nuclear bridges or nuclear buds in HepG2 cells. • Cloisite{sup ®}Na{sup +} induces changes in the gene expression. • Gene alteration is presented mainly after 24 h of exposure to Cloisite{sup ®}Na{sup +}. - Abstract: Montmorillonite, also known as Cloisite{sup ®}Na{sup +} (CNa{sup +}), is a natural clay with a wide range of well-documented and novel applications, such as pharmaceutical products or food packaging. Although considered a low toxic product, the expected increased exposure to CNa{sup +} arises concern on the potential consequences on human and environmental health especially as its genotoxicity has scarcely been investigated so far. Thus, we investigated, for the first time, the influence of non-cytotoxic concentrations of CNa{sup +} (15.65, 31.25 and 62.5 μg/mL) on genomic instability of human hepatoma cell line (HepG2) by determining the formation of micronuclei (MNi), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) with the Cytokinesis block micronucleus cytome assay. Further on we studied the influence of CNa{sup +} on the expression of several genes involved in toxicity mechanisms using the real-time quantitative PCR. The results showed that CNa{sup +} increased the number of MNi, while the numbers of NBUDs and NPBs were not affected. In addition it deregulated genes in all the groups studied, mainly after longer time of exposure. These findings provide the evidence that CNa{sup +} is potentially genotoxic. Therefore further studies that will elucidate the molecular mechanisms involved in toxic activity of CNa{sup +} are needed for hazard identification and human safety assessment.

Decreasing prevalence of multi-drugs resistant Mycobacterium tuberculosis in Nashik City, India

OpenAIRE

More, Arun Punaji; Nagdawane, Ramkrishna Panchamrao; Gangurde, Aniket K

2013-01-01

Objective: In India, increasing prevalence of multi-drug resistant tuberculosis (MDR) has aggravated the control oftuberculosis problem. In many urban and semi-urban regions of India, no surveillance data of multidrug resistance inMycobacterium tuberculosisis available.Methods: A surveillance study on multidrug resistance was carried out in semi-urban and rural regions in and aroundNashik City of Maharashtra, India. The surveillance study was conducted in this region found that the prevalence...

Mutations of the central tyrosines of putative cholesterol recognition amino acid consensus (CRAC) sequences modify folding, activity, and sterol-sensing of the human ABCG2 multidrug transporter.

Science.gov (United States)

Gál, Zita; Hegedüs, Csilla; Szakács, Gergely; Váradi, András; Sarkadi, Balázs; Özvegy-Laczka, Csilla

2015-02-01

Human ABCG2 is a plasma membrane glycoprotein causing multidrug resistance in cancer. Membrane cholesterol and bile acids are efficient regulators of ABCG2 function, while the molecular nature of the sterol-sensing sites has not been elucidated. The cholesterol recognition amino acid consensus (CRAC, L/V-(X)(1-5)-Y-(X)(1-5)-R/K) sequence is one of the conserved motifs involved in cholesterol binding in several proteins. We have identified five potential CRAC motifs in the transmembrane domain of the human ABCG2 protein. In order to define their roles in sterol-sensing, the central tyrosines of these CRACs (Y413, 459, 469, 570 and 645) were mutated to S or F and the mutants were expressed both in insect and mammalian cells. We found that mutation in Y459 prevented protein expression; the Y469S and Y645S mutants lost their activity; while the Y570S, Y469F, and Y645F mutants retained function as well as cholesterol and bile acid sensitivity. We found that in the case of the Y413S mutant, drug transport was efficient, while modulation of the ATPase activity by cholesterol and bile acids was significantly altered. We suggest that the Y413 residue within a putative CRAC motif has a role in sterol-sensing and the ATPase/drug transport coupling in the ABCG2 multidrug transporter. Copyright © 2014. Published by Elsevier B.V.

Hepatoscintiangiography of normal liver and its alteration in hepatomas and liver abscess

International Nuclear Information System (INIS)

Bahk, Y.W.; Chung, S.K.

1984-01-01

This study was performed to establish normal hepatoscintiangiographic (HSA) pattern of hepatic blood flow and to investigate differential HSA findings of primary and metastatic carcinomas and abscess of the liver. HSA was carried out after intravenous bolus injection of l0 mCi of Tc-99m-phytate by obtaining sequential anterior images of 1-second exposure for 16 seconds. Observations included (1) baseline study of normal hepatic blood flow patterns by correlating with contrast angiogram, (2) time-sequence phasing of normal HSA, and (3) analysis of altered patterns in primary and metastatic carcinomas and abscess of the liver. Results were: (1) Normal HSA demonstrated 3 distinct phases of arterialization (AP), arterial hepatrogram (AHP), and portal venous hepatogram (PVHP). The means of each phase were 5.3, 6.3, and 8.3 seconds, respectively. Portal vein could be seen in all but one of 20 normal subjects. (2) Pattern changes in disease groups were early start of AP in carcinomas and very early start of AP in abscess. AP became prolonged in all disease groups. (3) Distinction between AHP and PVHP was sharp in metastasis and abscess but was unsharp in primary hepatoma. Cold area or areas became vascularized in primary hepatoma but not in abscess. Cold areas of metastasis were inhomogenously vascularized in late AP and throughout AHP and became relatively avascular as PVHP began. The cold area of abscess showed rim enhancement during AH and APH. These differences in HSA pattern were very useful in differential diagnosis of the diseases studied

Hospital costs of nosocomial multi-drug resistant Pseudomonas aeruginosa acquisition

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Morales Eva

2012-05-01

Full Text Available Abstract Background We aimed to assess the hospital economic costs of nosocomial multi-drug resistant Pseudomonas aeruginosa acquisition. Methods A retrospective study of all hospital admissions between January 1, 2005, and December 31, 2006 was carried out in a 420-bed, urban, tertiary-care teaching hospital in Barcelona (Spain. All patients with a first positive clinical culture for P. aeruginosa more than 48 h after admission were included. Patient and hospitalization characteristics were collected from hospital and microbiology laboratory computerized records. According to antibiotic susceptibility, isolates were classified as non-resistant, resistant and multi-drug resistant. Cost estimation was based on a full-costing cost accounting system and on the criteria of clinical Activity-Based Costing methods. Multivariate analyses were performed using generalized linear models of log-transformed costs. Results Cost estimations were available for 402 nosocomial incident P. aeruginosa positive cultures. Their distribution by antibiotic susceptibility pattern was 37.1% non-resistant, 29.6% resistant and 33.3% multi-drug resistant. The total mean economic cost per admission of patients with multi-drug resistant P. aeruginosa strains was higher than that for non-resistant strains (15,265 vs. 4,933 Euros. In multivariate analysis, resistant and multi-drug resistant strains were independently predictive of an increased hospital total cost in compared with non-resistant strains (the incremental increase in total hospital cost was more than 1.37-fold and 1.77-fold that for non-resistant strains, respectively. Conclusions P. aeruginosa multi-drug resistance independently predicted higher hospital costs with a more than 70% increase per admission compared with non-resistant strains. Prevention of the nosocomial emergence and spread of antimicrobial resistant microorganisms is essential to limit the strong economic impact.

Association between HIV/AIDS and multi-drug resistance tuberculosis: a systematic review and meta-analysis.

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Yonatan Moges Mesfin

Full Text Available BACKGROUND: Human immunodeficiency virus (HIV, multi-drug resistant tuberculosis (MDR is emerging as major challenge facing tuberculosis control programs worldwide particularly in Asia and Africa. Findings from different studies on associations of HIV co-infection and drug resistance among patients with TB have been contradictory (discordant. Some institution based studies found strongly increased risks for multi-drug resistant TB (MDR TB among patients co-infected with TB and HIV, whereas other studies found no increased risk (it remains less clear in community based studies. The aim was to conduct a systematic review and meta-analysis of the association between multi-drug resistant tuberculosis and HIV infection. METHODS AND FINDINGS: Systematic review of the published literature of observational studies was conducted. Original studies were identified using databases of Medline/Pubmed, Google Scholar and HINARI. The descriptions of original studies were made using frequency and forest plot. Publication bias was assessed using Funnel plot graphically and Egger weighted and Begg rank regression tests statistically. Heterogeneity across studies was checked using Cochrane Q test statistic and I(2. Pool risk estimates of MDR-TB and sub-grouping analysis were computed to analyze associations with HIV. Random effects of the meta-analysis of all 24 observational studies showed that HIV is associated with a marginal increased risk of multi-drug resistant tuberculosis (estimated Pooled OR 1.24; 95%, 1.04-1.43. Subgroup analyses showed that effect estimates were higher (Pooled OR 2.28; 95%, 1.52-3.04 for primary multi-drug resistance tuberculosis and moderate association between HIV/AIDS and MDR-TB among population based studies and no significant association in institution settings. CONCLUSIONS: This study demonstrated that there is association between MDR-TB and HIV. Capacity for diagnosis of MDR-TB and initiating and scale up of antiretroviral

Kinetic imaging of NPC1L1 and sterol trafficking between plasma membrane and recycling endosomes in hepatoma cells

DEFF Research Database (Denmark)

Hartwig Petersen, Nicole; Færgeman, Nils J; Yu, Liqing

2008-01-01

fluorescent protein (NPC1L1-EGFP) and cholesterol analogues in hepatoma cells. At steady state about 42% of NPC1L1 resided in the transferrin (Tf) positive, sterol enriched endocytic recycling compartment (ERC), while time-lapse microscopy demonstrated NPC1L1 traffic between plasma membrane and ERC...... the ERC to the plasma membrane. NPC1L1-EGFP facilitated transport of fluorescent sterols from the plasma membrane to the ERC. Insulin induced translocation of vesicles containing NPC1L1 and fluorescent sterol from the ERC to the cell membrane. Upon polarization of hepatoma cells NPC1L1 resided almost...... exclusively in the canalicular membrane, where the protein is highly mobile. Our study demonstrates dynamic trafficking of NPC1L1 between cell surface and intracellular compartments and suggests that this transport is involved in NPC1L1 mediated cellular sterol uptake....

The multidrug transporter ABCG2 (BCRP) is inhibited by plant-derived cannabinoids.

Science.gov (United States)

Holland, M L; Lau, D T T; Allen, J D; Arnold, J C

2007-11-01

Cannabinoids are used therapeutically for the palliation of the adverse side effects associated with cancer chemotherapy. However, cannabinoids also inhibit both the activity and expression of the multidrug transporter, P-glycoprotein in vitro. Here we address the interaction of cannabinol (CBN), cannabidiol (CBD) and delta 9-tetrahydrocannabinol (THC) with the related multidrug transporter, ABCG2. Cannabinoid inhibition of Abcg2/ABCG2 was assessed using flow cytometric analysis of substrate accumulation and ATPase activity assays. The cytotoxicity and chemosensitization by cannabinoids was determined with cell viability assays. Expression of cannabinoid and vanilloid receptors was assessed using reverse transcriptase polymerase chain reaction, and cannabinoid modulation of ABCG2 expression was examined using immunoblotting. CBN, CBD and THC increased the intracellular accumulation of the Abcg2/ABCG2 substrate, mitoxantrone, in an over-expressing cell line. The THC metabolite, (-)-11-nor-9-carboxy-delta 9-THC was much less potent. The plant cannabinoids inhibited both basal and substrate stimulated ATPase activity of human ABCG2. Cannabinoid cytotoxicity occurred in the absence of known cannabinoid cell surface receptors, and only at concentrations higher than those required for Abcg2/ABCG2 inhibition. Sub-toxic concentrations of the cannabinoids resensitized the overexpressing cell line to the cytotoxic effect of Abcg2/ABCG2 substrates, mitoxantrone and topotecan. This occurred in the absence of any effect on ABCG2 expression. Cannabinoids are novel Abcg2/ABCG2 inhibitors, reversing the Abcg2-mediated multidrug-resistant phenotype in vitro. This finding may have implications for the co-administration of cannabinoids with pharmaceuticals that are ABCG2 substrates.

Multidrug resistance in lactic acid bacteria : molecular mechanisms and clinical relevance

NARCIS (Netherlands)

van Veen, HW; Margolles, A; Putman, M; Sakamoto, K; Konings, WN

The active extrusion of cytotoxic compounds from the cell by multidrug transporters is one of the major causes of failure of chemotherapeutic treatment of tumor cells and of infections by pathogenic microorganisms. The secondary multidrug transporter LmrP and the ATP-binding cassette (ABC) type

Emergence of a Clonal Lineage of Multidrug-Resistant ESBL-Producing Salmonella Infantis Transmitted from Broilers and Broiler Meat to Humans in Italy between 2011 and 2014

DEFF Research Database (Denmark)

Franco, Alessia; Leekitcharoenphon, Pimlapas; Feltrin, Fabiola

2015-01-01

We report the spread of a clone of multidrug-resistant (MDR), ESBL-producing (blaCTX-M-1) Salmonella enterica subsp. enterica serovar Infantis, in the Italian broiler chicken industry and along the food-chain. This was first detected in Italy in 2011 and led to human infection in Italy in 2013....... This megaplasmid carried the ESBL gene blaCTX-M-1, and additional genes [tet(A), sul1, dfrA1 and dfrA14] mediating cefotaxime, tetracycline, sulfonamide, and trimethoprim resistance. It also contained genes conferring enhanced colonization capability, virulence (fimbriae, yersiniabactin), resistance and fitness...

Effects of Uptake of Hydroxyapatite Nanoparticles into Hepatoma Cells on Cell Adhesion and Proliferation

Directory of Open Access Journals (Sweden)

Meizhen Yin

2014-01-01

Full Text Available Hydroxyapatite nanoparticles (nano-HAPs were prepared by homogeneous precipitation, and size distribution and morphology of these nanoparticles were determined by laser particle analysis and transmission electron microscopy, respectively. Nano-HAPs were uniformly distributed, with rod-like shapes sizes ranging from 44.6 to 86.8 nm. Attached overnight, suspended, and proliferating Bel-7402 cells were repeatedly incubated with nano-HAPs. Inverted microscopy, transmission electron microscopy, and fluorescence microscopy were used to observe the cell adhesion and growth, the culture medium containing nano-HAPs, the cell ultrastructure, and intracellular Ca2+ labeled with a fluo-3 calcium fluorescent probe. The results showed that nano-HAPs inhibited proliferation of Bel-7402 cells and, caused an obvious increase in the concentration of intracellular Ca2+, along with significant changes in the cell ultrastructure. Moreover, nano-HAPs led suspended cells and proliferating cells after trypsinized that did not attach to the bottom of the culture bottle died. Nano-HAPs continuously entered these cells. Attached, suspended, and proliferating cells endocytosed nano-HAPs, and nanoparticle-filled vesicles were in the cytoplasm. Therefore, hepatoma cellular uptake of nano-HAPs through endocytosis was very active and occurred continuously. Nano-HAPs affected proliferation and adhesion of hepatoma cells probably because uptake of nano-HAPs blocked integrin-mediated cell adhesion, which may have potential significance in inhibiting metastatic cancer cells to their target organ.

Divide and conquer: processive transport enables multidrug transporters to tackle challenging drugs

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Nir Fluman

2014-09-01

Full Text Available Multidrug transporters are membrane proteins that catalyze efflux of antibiotics and other toxic compounds from cells, thereby conferring drug resistance on various organisms. Unlike most solute transporters that transport a single type of compound or similar analogues, multidrug transporters are extremely promiscuous. They transport a broad spectrum of dissimilar drugs and represent a serious obstacle to antimicrobial or anticancer chemotherapy. Many challenging aspects of multidrug transporters, which are unique, have been studied in detail, including their ability to interact with chemically unrelated drugs, and how they utilize energy to drive efflux of compounds that are not only structurally but electrically different. A new and surprising dimension of the promiscuous nature of multidrug transporters has been described recently: they can move long molecules through the membrane in a processive manner.

Quantitative analysis of MDR1 (multidrug resistance) gene expression in human tumors by polymerase chain reaction

International Nuclear Information System (INIS)

Noonan, K.E.; Beck, C.; Holzmayer, T.A.; Chin, J.E.; Roninson, I.B.; Wunder, J.S.; Andrulis, I.L.; Gazdar, A.F.; Willman, C.L.; Griffith, B.; Von Hoff, D.D.

1990-01-01

The resistance of tumor cells ot chemotheraprutic drugs is a major obstacle to successful cancer chemotherapy. In human cells, expression of the MDR1 gene, encoding a transmembrane efflux pump (P-glycoprotein), leads to decreased intracellular accumulation and resistance to a variety of lipophilic drugs (multidrug resistance; MDR). The levels of MDR in cell lines selected in bitro have been shown to correlate with the steady-state levels of MDR1 mRNA and P-glycoprotein. In cells with a severalfold increase in cellular drug resistance, MDR1 expression levels are close to the limits of detection by conventional assays. MDR1 expression has been frequently observed in human tumors after chemotherapy and in some but not all types of clinically refactory tumors untreated with chemotherapeutic drugs. The authors have devised a highly sensitive, specific, and quantitative protocol for measuring the levels of MDR1 mRNA in clincal samples, based on the polymerase chain reaction. They have used this assay to measure MDR1 gene expression in MDR cell lines and >300 normal tissues, tumor-derived cell lines, and clinical specimens of untreated tumors of the types in which MDR1 expression was rarely observed by standard assays. Low levels of MDR1 expression were found by polymerase chain reaction in most solid tumors and leukemias tested. The frequency of samples without detectable MDR1 expression varied among different types of tumors; MDR1-negative samples were ost common among tumor types known to be relatively responsive to chemotherapy

The multidrug ABC transporter BmrC/BmrD of Bacillus subtilis is regulated via a ribosome-mediated transcriptional attenuation mechanism

NARCIS (Netherlands)

Reilman, Ewoud; Mars, Ruben A. T.; van Dijl, Jan Maarten; Denham, Emma L.

2014-01-01

Expression of particular drug transporters in response to antibiotic pressure is a critical element in the development of bacterial multidrug resistance, and represents a serious concern for human health. To obtain a better understanding of underlying regulatory mechanisms, we have dissected the

Characterization of a multidrug-resistant Salmonella enterica serovar Heidelberg outbreak strain in commercial turkeys: Colonization, transmission, and host transcriptional response

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In recent years, multidrug-resistant (MDR) Salmonella enterica serovar Heidelberg has been associated with numerous human foodborne illness outbreaks due to consumption of poultry. For example, in 2011, an MDR S. Heidelberg outbreak associated with ground turkey sickened 136 individuals and resulted...

The multidrug resistance 1 gene Abcb1 in brain and placenta: comparative analysis in human and guinea pig.

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Pappas, Jane J; Petropoulos, Sophie; Suderman, Matthew; Iqbal, Majid; Moisiadis, Vasilis; Turecki, Gustavo; Matthews, Stephen G; Szyf, Moshe

2014-01-01

The Multidrug Resistance 1 (MDR1; alternatively ABCB1) gene product P-glycoprotein (P-gp), an ATP binding cassette transporter, extrudes multiple endogenous and exogenous substrates from the cell, playing an important role in normal physiology and xenobiotic distribution and bioavailability. To date, the predominant animal models used to investigate the role of P-gp have been the mouse and rat, which have two distinct genes, Abcb1a and Abcb1b. In contrast, the human has a single gene, ABCB1, for which only a single isoform has been validated. We and others have previously shown important differences between Abcb1a and Abcb1b, limiting the extrapolation from rodent findings to the human. Since the guinea pig has a relatively long gestation, hemomonochorial placentation and neuroanatomically mature offspring, it is more similar to the human, and may provide a more comparable model for investigating the regulation of P-gp in the brain and placenta, however, to date, the Abcb1 gene in the guinea pig remains to be characterized. The placenta and fetal brain are barrier sites that express P-gp and that play a critical role of protection of the fetus and the fetal brain from maternally administered drugs and other xenobiotics. Using RNA sequencing (RNA-seq), reverse transcription-polymerase chain reaction (RT-PCR) and quantitative PCR (QPCR) to sequence the expressed isoforms of guinea pig Abcb1, we demonstrate that like the human, the guinea pig genome contains one gene for Abcb1 but that it is expressed as at least three different isoforms via alternative splicing and alternate exon usage. Further, we demonstrate that these isoforms are more closely related to human than to rat or mouse isoforms. This striking, overall similarity and evolutionary relatedness between guinea pig Abcb1 and human ABCB1 indicate that the guinea pig represents a relevant animal model for investigating the function and regulation of P-gp in the placenta and brain.

Hepatoma-derived growth factor-related protein-3 is a novel angiogenic factor.

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Michelle E LeBlanc

Full Text Available Hepatoma-derived growth factor-related protein-3 (Hdgfrp3 or HRP-3 was recently reported as a neurotrophic factor and is upregulated in hepatocellular carcinoma to promote cancer cell survival. Here we identified HRP-3 as a new endothelial ligand and characterized its in vitro and in vivo functional roles and molecular signaling. We combined open reading frame phage display with multi-round in vivo binding selection to enrich retinal endothelial ligands, which were systematically identified by next generation DNA sequencing. One of the identified endothelial ligands was HRP-3. HRP-3 expression in the retina and brain was characterized by Western blot and immunohistochemistry. Cell proliferation assay showed that HRP-3 stimulated the growth of human umbilical vein endothelial cells (HUVECs. HRP-3 induced tube formation of HUVECs in culture. Wound healing assay indicated that HRP-3 promoted endothelial cell migration. HRP-3 was further confirmed for its in vitro angiogenic activity by spheroid sprouting assay. HRP-3 extrinsically activated the extracellular-signal-regulated kinase ½ (ERK1/2 pathway in endothelial cells. The angiogenic activity of HRP-3 was independently verified by mouse cornea pocket assay. Furthermore, in vivo Matrigel plug assay corroborated HRP-3 activity to promote new blood vessel formation. These results demonstrated that HRP-3 is a novel angiogenic factor.

miR-297 modulates multidrug resistance in human colorectal carcinoma by down-regulating MRP-2.

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Xu, Ke; Liang, Xin; Shen, Ke; Cui, Daling; Zheng, Yuanhong; Xu, Jianhua; Fan, Zhongze; Qiu, Yanyan; Li, Qi; Ni, Lei; Liu, Jianwen

2012-09-01

Colorectal carcinoma is a frequent cause of cancer-related death in men and women. miRNAs (microRNAs) are endogenous small non-coding RNAs that regulate gene expression negatively at the post-transcriptional level. In the present study we investigated the possible role of microRNAs in the development of MDR (multidrug resistance) in colorectal carcinoma cells. We analysed miRNA expression levels between MDR colorectal carcinoma cell line HCT116/L-OHP cells and their parent cell line HCT116 using a miRNA microarray. miR-297 showed lower expression in HCT116/L-OHP cells compared with its parental cells. MRP-2 (MDR-associated protein 2) is an important MDR protein in platinum-drug-resistance cells and is a predicted target of miR-297. Additionally miR-297 was down-regulated in a panel of human colorectal carcinoma tissues and negatively correlated with expression levels of MRP-2. Furthermore, we found that ectopic expression of miR-297 in MDR colorectal carcinoma cells reduced MRP-2 protein level and sensitized these cells to anti-cancer drugs in vitro and in vivo. Taken together, our findings suggest that miR-297 could play a role in the development of MDR in colorectal carcinoma cells, at least in part by modulation of MRP-2.

The human hepatocyte cell lines IHH and HepaRG : models to study glucose, lipid and lipoprotein metabolism

NARCIS (Netherlands)

Samanez, Carolina Huaman; Caron, Sandrine; Briand, Olivier; Dehondt, Helene; Duplan, Isabelle; Kuipers, Folkert; Hennuyer, Nathalie; Clavey, Veronique; Staels, Bart

Metabolic diseases reach epidemic proportions. A better knowledge of the associated alterations in the metabolic pathways in the liver is necessary. These studies need in vitro human cell models. Several human hepatoma models are used, but the response of many metabolic pathways to physiological

Stimulation of Hepatoma Cell Invasiveness and Metastatic Potential by Proteins Secreted From Irradiated Nonparenchymal Cells

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Zhou Leyuan [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Zhiming [Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Gao Yabo [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Lingyan [Experimental Research Center, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Zhaochong, E-mail: zeng.zhaochong@zs-hospital.sh.cn [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China)

2012-11-01

Purpose: To determine whether factors secreted by irradiated liver nonparenchymal cells (NPCs) may influence invasiveness and/or metastatic potential of hepatocellular carcinoma (HCC) cells and to elucidate a possible mechanism for such effect. Methods and Materials: Primary rat NPCs were cultured and divided into irradiated (10-Gy X-ray) and nonirradiated groups. Forty-eight hours after irradiation, conditioned medium from irradiated (SR) or nonirradiated (SnonR) cultures were collected and added to sublethally irradiated cultures of the hepatoma McA-RH7777 cell line. Then, hepatoma cells were continuously passaged for eight generations (RH10Gy-SR and RH10Gy-SnonR). The invasiveness and metastatic potential of McA-RH7777, RH10Gy-SnonR, and RH10Gy-SR cells were evaluated using an in vitro gelatinous protein (Matrigel) invasion and an in vivo metastasis assay. In addition, SR and SnonR were tested using rat cytokine antibody arrays and enzyme-linked immunosorbent assay (ELISA). Results: In vitro gelatinous protein invasion assay indicated that the numbers of invading cells was significantly higher in RH10Gy-SR (40 {+-} 4.74) than in RH10Gy-SnonR (30.6 {+-} 3.85) cells, and lowest in McA-RH7777 (11.4 {+-} 3.56) cells. The same pattern was observed in vivo in a lung metastasis assay, as evaluated by number of metastatic lung nodules seen with RH10Gy-SR (28.83 {+-} 5.38), RH10Gy-SnonR (22.17 {+-} 4.26), and McA-RH7777 (8.3 {+-} 3.8) cells. Rat cytokine antibody arrays and ELISA demonstrated that metastasis-promoting cytokines (tumor necrosis factor-{alpha} and interleukin-6), circulating growth factors (vascular endothelial growth factor and epidermal growth factor), and metalloproteinases (MMP-2 and MMP-9) were upregulated in SR compared with SnonR. Conclusions: Radiation can increase invasiveness and metastatic potential of sublethally irradiated hepatoma cells, and soluble mediators released from irradiated NPCs promote this potential. Increased secretion of

Measuring and modeling of binary mixture effects of pharmaceuticals and nickel on cell viability/cytotoxicity in the human hepatoma derived cell line HepG2

International Nuclear Information System (INIS)

Rudzok, S.; Schlink, U.; Herbarth, O.; Bauer, M.

2010-01-01

The interaction of drugs and non-therapeutic xenobiotics constitutes a central role in human health risk assessment. Still, available data are rare. Two different models have been established to predict mixture toxicity from single dose data, namely, the concentration addition (CA) and independent action (IA) model. However, chemicals can also act synergistic or antagonistic or in dose level deviation, or in a dose ratio dependent deviation. In the present study we used the MIXTOX model (EU project ENV4-CT97-0507), which incorporates these algorithms, to assess effects of the binary mixtures in the human hepatoma cell line HepG2. These cells possess a liver-like enzyme pattern and a variety of xenobiotic-metabolizing enzymes (phases I and II). We tested binary mixtures of the metal nickel, the anti-inflammatory drug diclofenac, and the antibiotic agent irgasan and compared the experimental data to the mathematical models. Cell viability was determined by three different methods the MTT-, AlamarBlue (registered) and NRU assay. The compounds were tested separately and in combinations. We could show that the metal nickel is the dominant component in the mixture, affecting an antagonism at low-dose levels and a synergism at high-dose levels in combination with diclofenac or irgasan, when using the NRU and the AlamarBlue assay. The dose-response surface of irgasan and diclofenac indicated a concentration addition. The experimental data could be described by the algorithms with a regression of up to 90%, revealing the HepG2 cell line and the MIXTOX model as valuable tool for risk assessment of binary mixtures for cytotoxic endpoints. However the model failed to predict a specific mode of action, the CYP1A1 enzyme activity.

[Impact of fluoroquinolone use on multidrug-resistant bacteria emergence].

Science.gov (United States)

Nseir, S; Ader, F; Marquette, C-H; Durocher, A

2005-01-01

During the last two decades, fluoroquinolone use has significantly increased in Europe and in the USA. This could be explained by the arrival of newer fluoroquinolones with antipneumoccal activity. Increased use of fluoroquinolones is associated with higher rates of bacterial resistance to these antibiotics. Resistance of Gram-negative bacilli to fluoroquinolones is increasing in industrialized countries. In addition, fluoroquinolone use has been identified as a risk factor for colonization and infection to methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumanni, extending-spectrum beta-lactamase producing Gram negative bacilli, and multidrug-resistant bacteria. Nosocomial infections due to multidrug-resistant bacteria are associated with higher mortality and morbidity rates. This could be related to more frequent inappropriate initial antibiotic treatment in these patients. Limiting the use of fluoroquinolones, limiting the duration of treatment with fluoroquinolones, and using appropriate dosage of these antibiotics could be suggested to reduce resistance to these antibiotics and to reduce the emergence of multidrug-resistant bacteria.

A Salmonella nanoparticle mimic overcomes multidrug resistance in tumours.

Science.gov (United States)

Mercado-Lubo, Regino; Zhang, Yuanwei; Zhao, Liang; Rossi, Kyle; Wu, Xiang; Zou, Yekui; Castillo, Antonio; Leonard, Jack; Bortell, Rita; Greiner, Dale L; Shultz, Leonard D; Han, Gang; McCormick, Beth A

2016-07-25

Salmonella enterica serotype Typhimurium is a food-borne pathogen that also selectively grows in tumours and functionally decreases P-glycoprotein (P-gp), a multidrug resistance transporter. Here we report that the Salmonella type III secretion effector, SipA, is responsible for P-gp modulation through a pathway involving caspase-3. Mimicking the ability of Salmonella to reverse multidrug resistance, we constructed a gold nanoparticle system packaged with a SipA corona, and found this bacterial mimic not only accumulates in tumours but also reduces P-gp at a SipA dose significantly lower than free SipA. Moreover, the Salmonella nanoparticle mimic suppresses tumour growth with a concomitant reduction in P-gp when used with an existing chemotherapeutic drug (that is, doxorubicin). On the basis of our finding that the SipA Salmonella effector is fundamental for functionally decreasing P-gp, we engineered a nanoparticle mimic that both overcomes multidrug resistance in cancer cells and increases tumour sensitivity to conventional chemotherapeutics.

Identification and characterization of multidrug-resistant Salmonella enterica serotype Albert isolates in the United States.

Science.gov (United States)

Folster, Jason P; Campbell, Davina; Grass, Julian; Brown, Allison C; Bicknese, Amelia; Tolar, Beth; Joseph, Lavin A; Plumblee, Jodie R; Walker, Carrie; Fedorka-Cray, Paula J; Whichard, Jean M

2015-05-01

Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present, S. enterica is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19 S. enterica serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection. S. enterica serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant S. enterica serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Higher Desolvation Energy Reduces Molecular Recognition in Multi-Drug Resistant HIV-1 Protease

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Ladislau C. Kovari

2012-05-01

Full Text Available Designing HIV-1 protease inhibitors that overcome drug-resistance is still a challenging task. In this study, four clinical isolates of multi-drug resistant HIV-1 proteases that exhibit resistance to all the US FDA-approved HIV-1 protease inhibitors and also reduce the substrate recognition ability were examined. A multi-drug resistant HIV-1 protease isolate, MDR 769, was co-crystallized with the p2/NC substrate and the mutated CA/p2 substrate, CA/p2 P1’F. Both substrates display different levels of molecular recognition by the wild-type and multi-drug resistant HIV-1 protease. From the crystal structures, only limited differences can be identified between the wild-type and multi-drug resistant protease. Therefore, a wild-type HIV-1 protease and four multi-drug resistant HIV-1 proteases in complex with the two peptides were modeled based on the crystal structures and examined during a 10 ns-molecular dynamics simulation. The simulation results reveal that the multi-drug resistant HIV-1 proteases require higher desolvation energy to form complexes with the peptides. This result suggests that the desolvation of the HIV-1 protease active site is an important step of protease-ligand complex formation as well as drug resistance. Therefore, desolvation energy could be considered as a parameter in the evaluation of future HIV-1 protease inhibitor candidates.

Proteome analysis of multidrug-resistant, breast cancer–derived microparticles

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Deep Pokharel

2014-08-01

Full Text Available Cancer multidrug resistance (MDR occurs when cancer cells evade the cytotoxic actions of chemotherapeutics through the active efflux of drugs from within the cells. Our group have previously demonstrated that multidrug-resistant breast cancer cells spontaneously shed microparticles (MPs and that these MPs can transfer resistance to drug-responsive cells and confer MDR on those cells in as little as 4 h. Furthermore, we also showed that, unlike MPs derived from leukaemia cells, breast cancer–derived MPs display a tissue selectivity in the transfer of P-glycoprotein (P-gp, transferring the resistance protein only to malignant breast cells. This study aims to define the proteome of breast cancer–derived MPs in order to understand the differences in protein profiles between those shed from drug-resistant versus drug-sensitive breast cancer cells. In doing so, we detail the protein cargo required for the intercellular transfer of MDR to drug-sensitive recipient cells and the factors governing the transfer selectivity to malignant breast cells. We describe the first proteomic analysis of MPs derived from human breast cancer cells using SDS PAGE and liquid chromatography–tandem mass spectrometry (LC/MS/MS, in which we identify 120 unique proteins found only in drug-resistant, breast cancer–derived MPs. Our results demonstrate that the MP-mediated transfer of P-gp to recipient cells occurs alongside CD44; the Ezrin, Radixin and Moesin protein family (ERM; and cytoskeleton motor proteins within the MP cargo.

Molecular properties of bacterial multidrug transporters

NARCIS (Netherlands)

Putman, M; van Veen, HW; Konings, WN

2000-01-01

One of the mechanisms that bacteria utilize to evade the toxic effects of antibiotics is the active extrusion of structurally unrelated drugs from the cell. Both intrinsic and acquired multidrug transporters play an important role in antibiotic resistance of several pathogens, including Neisseria

pH-Responsive Hyaluronic Acid-Based Mixed Micelles for the Hepatoma-Targeting Delivery of Doxorubicin

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Jing-Liang Wu

2016-03-01

Full Text Available The tumor targetability and stimulus responsivity of drug delivery systems are crucial in cancer diagnosis and treatment. In this study, hepatoma-targeting mixed micelles composed of a hyaluronic acid–glycyrrhetinic acid conjugate and a hyaluronic acid-l-histidine conjugate (HA–GA/HA–His were prepared through ultrasonic dispersion. The formation and characterization of the mixed micelles were confirmed via 1H-NMR, particle size, and ζ potential measurements. The in vitro cellular uptake of the micelles was evaluated using human liver carcinoma (HepG2 cells. The antitumor effect of doxorubicin (DOX-loaded micelles was investigated in vitro and in vivo. Results indicated that the DOX-loaded HA–GA/HA–His micelles showed a pH-dependent controlled release and were remarkably absorbed by HepG2 cells. Compared with free DOX, the DOX-loaded HA–GA/HA–His micelles showed a higher cytotoxicity to HepG2 cells. Moreover, the micelles effectively inhibited tumor growth in H22 cell-bearing mice. These results suggest that the HA–GA/HA–His mixed micelles are a good candidate for drug delivery in the prevention and treatment of hepatocarcinoma.

Response of Hepatoma 9618a and Normal Liver to Host Carbogen and Carbon Monoxide Breathing

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Simon P. Robinson

1999-12-01

Full Text Available The effects of hyperoxia (induced by host carbogen 95% oxygen/5% carbon dioxide breathing. and hypoxia (induced by host carbon monoxide CO at 660 ppm. breathing were compared by using noninvasive magnetic resonance (MR methods to gain simultaneous information on blood flow/oxygenation and the bioenergetic status of rat Morris H9618a hepatomas. Both carbogen and CO breathing induced a 1.5- to 2-fold increase in signal intensity in blood oxygenation level dependent (BOLD MR images. This was due to a decrease in deoxyhemoglobin (deoxyHb, which acts as an endogenous contrast agent, caused either by formation of oxyhemoglobin in the case of carbogen breathing, or carboxyhemoglobin with CO breathing. The results were confirmed by observation of similar changes in deoxyHb in arterial blood samples examined ex vivo after carbogen or CO breathing. There was no change in nucleoside triphosphates (NTP/PI in either tumor or liver after CO breathing, whereas NTP/Pl increased twofold in the hepatoma (but not in the liver after carbogen breathing. No changes in tumor intracellular pH were seen after either treatment, whereas extracellular pH became more alkaline after CO breathing and more acid after carbogen breathing, respectively. This tumor type and the liver are unaffected by CO breathing at 660 ppm, which implies an adequate oxygen supply.

Border Malaria Associated with Multidrug Resistance on Thailand-Myanmar and Thailand-Cambodia Borders: Transmission Dynamic, Vulnerability, and Surveillance

Science.gov (United States)

Bhumiratana, Adisak; Intarapuk, Apiradee; Sorosjinda-Nunthawarasilp, Prapa; Maneekan, Pannamas; Koyadun, Surachart

2013-01-01

This systematic review elaborates the concepts and impacts of border malaria, particularly on the emergence and spread of Plasmodium falciparum and Plasmodium vivax multidrug resistance (MDR) malaria on Thailand-Myanmar and Thailand-Cambodia borders. Border malaria encompasses any complex epidemiological settings of forest-related and forest fringe-related malaria, both regularly occurring in certain transmission areas and manifesting a trend of increased incidence in transmission prone areas along these borders, as the result of interconnections of human settlements and movement activities, cross-border population migrations, ecological changes, vector population dynamics, and multidrug resistance. For regional and global perspectives, this review analyzes and synthesizes the rationales pertaining to transmission dynamics and the vulnerabilities of border malaria that constrain surveillance and control of the world's most MDR falciparum and vivax malaria on these chaotic borders. PMID:23865048

Recent advances in live cell imaging of hepatoma cells

Science.gov (United States)

2014-01-01

Live cell imaging enables the study of dynamic processes of living cells in real time by use of suitable reporter proteins and the staining of specific cellular structures and/or organelles. With the availability of advanced optical devices and improved cell culture protocols it has become a rapidly growing research methodology. The success of this technique relies mainly on the selection of suitable reporter proteins, construction of recombinant plasmids possessing cell type specific promoters as well as reliable methods of gene transfer. This review aims to provide an overview of the recent developments in the field of marker proteins (bioluminescence and fluorescent) and methodologies (fluorescent resonance energy transfer, fluorescent recovery after photobleaching and proximity ligation assay) employed as to achieve an improved imaging of biological processes in hepatoma cells. Moreover, different expression systems of marker proteins and the modes of gene transfer are discussed with emphasis on the study of lipid droplet formation in hepatocytes as an example. PMID:25005127

Percutaneous Ethanol Injection of Unresectable Medium-to-Large-Sized Hepatomas Using a Multipronged Needle: Efficacy and Safety

International Nuclear Information System (INIS)

Ho, C.S.; Kachura, J.R.; Gallinger, S.; Grant, D.; Greig, P.; McGilvray, I.; Knox, J.; Sherman, M.; Wong, F.; Wong, D.

2007-01-01

Fine needles with an end hole or multiple side holes have traditionally been used for percutaneous ethanol injection (PEI) of hepatomas. This study retrospectively evaluates the safety and efficacy of PEI of unresectable medium-to-large (3.5-9 cm) hepatomas using a multipronged needle and with conscious sedation. Twelve patients, eight men and four women (age 51-77 years; mean: 69) received PEI for hepatomas, mostly subcapsular or exophytic in location with average tumor size of 5.6 cm (range: 3.5-9.0 cm). Patients were consciously sedated and an 18G retractable multipronged needle (Quadrafuse needle; Rex Medical, Philadelphia, PA) was used for injection under real-time ultrasound guidance. By varying the length of the prongs and rotating the needle, the alcohol was widely distributed within the tumor. The progress of ablation was monitored by contrast-enhanced ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) after each weekly injection and within a month after the final (third) injection and 3 months thereafter. An average total of 63 mL (range: 20-154 ml) of alcohol was injected per patient in an average of 2.3 sessions. Contrast-enhanced CT, ultrasound, or MRI was used to determine the degree of necrosis. Complete necrosis was noted in eight patients (67%), near-complete necrosis (90-99%) in two (16.7%), and partial success (50-89%) in two (16.7%). Follow-up in the first 9 months showed local recurrence in two patients and new lesions in another. There was no mortality. One patient developed renal failure, liver failure, and localized perforation of the stomach. He responded to medical treatment and surgery was not required for the perforation. One patient had severe postprocedural abdominal pain and fever, and another had transient hyperbilirubinemia; both recovered with conservative treatment. PEI with a multipronged needle is a new, safe, and efficacious method in treating medium-to-large-sized hepatocellular carcinoma under conscious

Targeted multidrug delivery system to overcome chemoresistance in breast cancer

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Tang Y

2017-01-01

Full Text Available Yuan Tang,1 Fariborz Soroush,1 Zhaohui Tong,2 Mohammad F Kiani,1 Bin Wang1,3 1Department of Mechanical Engineering, Temple University, Philadelphia, PA, 2Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL, 3Department of Biomedical Engineering, Widener University, Chester, PA, USA Abstract: Chemotherapy has been widely used in breast cancer patients to reduce tumor size. However, most anticancer agents cannot differentiate between cancerous and normal cells, resulting in severe systemic toxicity. In addition, acquired drug resistance during the chemotherapy treatment further decreases treatment efficacy. With the proper treatment strategy, nanodrug carriers, such as liposomes/immunoliposomes, may be able to reduce undesired side effects of chemotherapy, to overcome the acquired multidrug resistance, and to further improve the treatment efficacy. In this study, a novel combinational targeted drug delivery system was developed by encapsulating antiangiogenesis drug bevacizumab into liposomes and encapsulating chemotherapy drug doxorubicin (DOX into immunoliposomes where the human epidermal growth factor receptor 2 (HER2 antibody was used as a targeting ligand. This novel combinational system was tested in vitro using a HER2 positive and multidrug resistant breast cancer cell line (BT-474/MDR, and in vivo using a xenograft mouse tumor model. In vitro cell culture experiments show that immunoliposome delivery led to a high cell nucleus accumulation of DOX, whereas free DOX was observed mostly near the cell membrane and in cytoplasm due to the action of P-gp. Combining liposomal bevacizumab with immunoliposomal DOX achieved the best tumor growth inhibition and the lowest toxicity. Tumor size decreased steadily within a 60-day observation period indicating a potential synergistic effect between DOX and bevacizumab through the targeted delivery. Our findings clearly indicate that tumor growth was significantly

Complete nucleotide sequence of the multidrug resistance IncA/C plasmid pR55 from Klebsiella pneumoniae isolated in 1969.

Science.gov (United States)

Doublet, Benoît; Boyd, David; Douard, Gregory; Praud, Karine; Cloeckaert, Axel; Mulvey, Michael R

2012-10-01

To determine the complete nucleotide sequence of the multidrug resistance IncA/C plasmid pR55 from a clinical Klebsiella pneumoniae strain that was isolated from a urinary tract infection in 1969 in a French hospital and compare it with those of contemporary emerging IncA/C plasmids. The plasmid was purified and sequenced using a 454 sequencing approach. After draft assembly, additional PCRs and walking reads were performed for gap closure. Sequence comparisons and multiple alignments with other IncA/C plasmids were done using the BLAST algorithm and CLUSTAL W, respectively. Plasmid pR55 (170 810 bp) revealed a shared plasmid backbone (>99% nucleotide identity) with current members of the IncA/C(2) multidrug resistance plasmid family that are widely disseminating antibiotic resistance genes. Nevertheless, two specific multidrug resistance gene arrays probably acquired from other genetic elements were identified inserted at conserved hotspot insertion sites in the IncA/C backbone. A novel transposon named Tn6187 showed an atypical mixed transposon configuration composed of two mercury resistance operons and two transposition modules that are related to Tn21 and Tn1696, respectively, and an In0-type integron. IncA/C(2) multidrug resistance plasmids have a broad host range and have been implicated in the dissemination of antibiotic resistance among Enterobacteriaceae from humans and animals. This typical IncA/C(2) genetic scaffold appears to carry various multidrug resistance gene arrays and is now also a successful vehicle for spreading AmpC-like cephalosporinase and metallo-β-lactamase genes, such as bla(CMY) and bla(NDM), respectively.

Multidrug transporters in lactic acid bacteria

NARCIS (Netherlands)

Mazurkiewicz, P; Sakamoto, K; Poelarends, GJ; Konings, WN

Gram-positive lactic acid bacteria possess several Multi-Drug Resistance systems (MDRs) that excrete out of the cell a wide variety of mainly cationic lipophilic cytotoxic compounds as well as many clinically relevant antibiotics. These MDRs are either proton/drug antiporters belonging to the major

DNA sequence analysis of plasmids from multidrug resistant Salmonella enterica serotype Heidelberg isolates.

Directory of Open Access Journals (Sweden)

Jing Han

Full Text Available Salmonella enterica serovar Heidelberg is among the most detected serovars in swine and poultry, ranks among the top five serotypes associated with human salmonellosis and is disproportionately associated with invasive infections and mortality in humans. Salmonella are known to carry plasmids associated with antimicrobial resistance and virulence. To identify plasmid-associated genes in multidrug resistant S. enterica serovar Heidelberg, antimicrobial resistance plasmids from five isolates were sequenced using the 454 LifeSciences pyrosequencing technology. Four of the isolates contained incompatibility group (Inc A/C multidrug resistance plasmids harboring at least eight antimicrobial resistance genes. Each of these strains also carried a second resistance plasmid including two IncFIB, an IncHI2 and a plasmid lacking an identified Inc group. The fifth isolate contained an IncI1 plasmid, encoding resistance to gentamicin, streptomycin and sulfonamides. Some of the IncA/C plasmids lacked the full concert of transfer genes and yet were able to be conjugally transferred, likely due to the transfer genes carried on the companion plasmids in the strains. Several non-IncA/C resistance plasmids also carried putative virulence genes. When the sequences were compared to previously sequenced plasmids, it was found that while all plasmids demonstrated some similarity to other plasmids, they were unique, often due to differences in mobile genetic elements in the plasmids. Our study suggests that Salmonella Heidelberg isolates harbor plasmids that co-select for antimicrobial resistance and virulence, along with genes that can mediate the transfer of plasmids within and among other bacterial isolates. Prevalence of such plasmids can complicate efforts to control the spread of S. enterica serovar Heidelberg in food animal and human populations.

Complete replication of hepatitis B virus and hepatitis C virus in a newly developed hepatoma cell line.

Science.gov (United States)

Yang, Darong; Zuo, Chaohui; Wang, Xiaohong; Meng, Xianghe; Xue, Binbin; Liu, Nianli; Yu, Rong; Qin, Yuwen; Gao, Yimin; Wang, Qiuping; Hu, Jun; Wang, Ling; Zhou, Zebin; Liu, Bing; Tan, Deming; Guan, Yang; Zhu, Haizhen

2014-04-01

The absence of a robust cell culture system for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection has limited the analysis of the virus lifecycle and drug discovery. We have established a hepatoma cell line, HLCZ01, the first cell line, to the authors' knowledge, supporting the entire lifecycle of both HBV and HCV. HBV surface antigen (HBsAg)-positive particles can be observed in the supernatant and the lumen of the endoplasmic reticulum of the cells via electron microscopy. Interestingly, HBV and HCV clinical isolates propagate in HLCZ01 cells. Both viruses replicate in the cells without evidence of overt interference. HBV and HCV entry are blocked by antibodies against HBsAg and human CD81, respectively, and the replication of HBV and HCV is inhibited by antivirals. HLCZ01 cells mount an innate immune response to virus infection. The cell line provides a powerful tool for exploring the mechanisms of virus entry and replication and the interaction between host and virus, facilitating the development of novel antiviral agents and vaccines.

Draft genome sequence of a multidrug-resistant Chryseobacterium indologenes isolate from Malaysia

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Choo Yee Yu

2016-03-01

Full Text Available Chryseobacterium indologenes is an emerging pathogen which poses a threat in clinical healthcare setting due to its multidrug-resistant phenotype and its common association with nosocomial infections. Here, we report the draft genome of a multidrug-resistant C. indologenes CI_885 isolated in 2014 from Malaysia. The 908,704-kb genome harbors a repertoire of putative antibiotic resistance determinants which may elucidate the molecular basis and underlying mechanisms of its resistant to various classes of antibiotics. The genome sequence has been deposited in DDBJ/EMBL/GenBank under the accession number LJOD00000000. Keywords: Chryseobacterium indologenes, Genome, Multi-drug resistant, blaIND, Next generation sequencing

Cell damage of hepatoma-22 cells exposed to continuous wave ultrasound.

Science.gov (United States)

Wang, Pan; Wang, Xiaobing; Liu, Quanhong

2012-01-01

The cellular response of hepatoma-22 cells to ultrasonic irradiation and the potential cause for the action were evaluated. Hepatoma-22 cells were subjected to ultrasound irradiation at a frequency of 2.17 MHz and a spatial average intensity of 1.6 W/cm2 for variable periods of time, and several biological parameters were analyzed. The terephthalic acid (TA) dosimetry method was used to evaluate the efficacies of irradiation parameters on the acoustic cavitation activity by monitoring hydroxyl radical (OH) production. Lactate dehydrogenase (LDH) leakage was assayed to investigate cell membrane integrity. The polarization value of fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH) was measured to monitor plasma membrane fluidity. The malonaldehyde content in cells was determined to reflect lipid peroxidation. Trypan blue exclusion was used to detect cell viability. Additionally, electron microscopy was used to observe morphological changes. The generation of intracellular reactive oxygen species, mitochondria swelling and the loss of mitochondria membrane potential were also investigated. The results showed that 1) the concentration of ·OH production by ultrasonic irradiation in air-saturated cell suspensions increased as ultrasound exposure time increased; 2) compared with control, lactate dehydrogenase leakage, the polarization value of 1,6-diphenyl-1,3,5-hexatriene, malonaldehyde content and cell lysis were significantly elevated when cells were treated by ultrasound for 60 s; 3) cytotoxicity by ultrasound irradiation was also accompanied by an increase in production of intracellular reactive oxygen species and dissipation of mitochondria membrane potential as well as by mitochondria swelling. Presently available information indicates that the plasma membrane and mitochondria are the main targets for ultrasound treatment, and free radicals formation such as ·OH due to ultrasound cavitation may play an important role in mediating these cellular response

Kaempferol increases apoptosis in human acute promyelocytic leukemia cells and inhibits multidrug resistance genes.

Science.gov (United States)

Moradzadeh, Maliheh; Tabarraei, Alijan; Sadeghnia, Hamid Reza; Ghorbani, Ahmad; Mohamadkhani, Ashraf; Erfanian, Saiedeh; Sahebkar, Amirhossein

2018-02-01

Acute promyelocytic leukemia (APL) is one of the most life-threatening hematological malignancies. Defects in the cell growth and apoptotic pathways are responsible for both disease pathogenesis and treatment resistance. Therefore, pro-apoptotic agents are potential candidates for APL treatment. Kaempferol is a flavonoid with antioxidant and anti-tumor properties. This study was designed to investigate the cytotoxic, pro-apoptotic, and differentiation-inducing effects of kaempferol on HL-60 and NB4 leukemia cells. Resazurin assay was used to determine cell viability following treatment with kaempferol (12.5-100 μM) and all-trans retinoic acid (ATRA; 10 μM; used as a positive control). Apoptosis and differentiation were also detected using propidium iodide and NBT staining techniques, respectively. Furthermore, the expression levels of genes involved in apoptosis (PI3 K, AKT, BCL2, BAX, p53, p21, PTEN, CASP3, CASP8, and CASP9), differentiation (PML-RAR and HDAC1), and multi-drug resistance (ABCB1 and ABCC1) were determined using quantitative real-time PCR. The protein expressions of Bax/Bcl2 and casp3 were confirmed using Western blot. The results showed that kaempferol decreased cell viability and increased subG1 population in the tested leukemic cells. This effect was associated with decreased expression of Akt, BCL2, ABCB1, and ABCC1 genes, while the expression of CASP3 and BAX/BCL-2 ratio were significantly increased at both gene and protein levels. Kaempferol promoted apoptosis and inhibited multidrug resistance in a concentration-dependent manner, without any differential effect on leukemic cells. In conclusion, this study suggested that kaempferol may be utilized as an appropriate alternative for ATRA in APL patients. © 2017 Wiley Periodicals, Inc.

Bystander effect in human hepatoma HepG2 cells caused by medium transfers at different times after high-LET carbon ion irradiation

International Nuclear Information System (INIS)

Wu Qingfeng; Li Qiang; Jin Xiaodong; Liu Xinguo; Dai Zhongying

2011-01-01

Although radiation-induced bystander effects have been well documented in a variety of biological systems, whether irradiated cells have the ability to generate bystander signaling persistently is still unclear and the clinical relevance of bystander effects in radiotherapy remains to be elucidated. This study examines tumor cellular bystander response to autologous medium from cell culture irradiated with high-linear energy transfer (LET) heavy ions at a therapeutically relevant dose in terms of clonogenic cell survival. In vitro experiments were performed using human hepatoma HepG2 cell line exposed to 100 keV/μm carbon ions at a dose of 2 Gy. Two different periods (2 and 12 h) after irradiation, irradiated cell conditioned medium (ICCM) and replenished fresh medium were harvested and then transferred to unirradiated bystander cells. Cellular bystander responses were measured with the different medium transfer protocols. Significant higher survival fractions of unirradiated cells receiving the media from the irradiated cultures at the different times post-irradiation than those of the control were observed. Even replenishing fresh medium for unirradiated cells which had been exposed to the ICCM for 12 h could not prevent the bystander cells from the increased survival fraction. These results suggest that the irradiated cells could release unidentified signal factor(s), which induced the increase in survival fraction for the unirradiated bystander cells, into the media sustainedly and the carbon ions triggered a cascade of signaling events in the irradiated cells rather than secreting the soluble signal factor(s) just at a short period after irradiation. Based on the observations in this study, the importance of bystander effect in clinical radiotherapy was discussed and incorporating the bystander effect into the current radiobiological models, which are applicable to heavy ion radiotherapy, is needed urgently.

Comparative study on lysosomal accumulation of 67Ga and 111In in Morris hepatoma 7316A

International Nuclear Information System (INIS)

Takeda, S.; Uchida, T.; Matsuzawa, T.

1977-01-01

Intracellular localization of 67 Ga and 111 In was investigated in Morris hepatoma 7316A and in normal Buffalo rat liver cells by a cell fractionation method at 48 hr after an intraperitoneal injection of the nuclides. Lysosomal fractions of the tumor and normal liver cells had the highest relative specific radioactivities of the nuclides (p 67 Ga (p 67 Ga seemed to indicate that 67 Ga determines lysosomal functions of tumor cells more precisely than 111 In

Crystal structure of the antigen-binding fragment of a monoclonal antibody specific for the multidrug-resistance-linked ABC transporter human P-glycoprotein

Energy Technology Data Exchange (ETDEWEB)

Esser, Lothar; Shukla, Suneet; Zhou, Fei; Ambudkar, Suresh V.; Xia, Di

2016-07-27

P-glycoprotein (P-gp) is a polyspecific ATP-dependent transporter linked to multidrug resistance in cancers that plays important roles in the pharmacokinetics of a large number of drugs. The drug-resistance phenotype of P-gp can be modulated by the monoclonal antibody UIC2, which specifically recognizes human P-gp in a conformation-dependent manner. Here, the purification, sequence determination and high-resolution structure of the Fab fragment of UIC2 (UIC2/Fab) are reported. Purified UIC2/Fab binds human P-gp with a 1:1 stoichiometry. Crystals of UIC2/Fab are triclinic (space groupP1), with unit-cell parametersa= 40.67,b= 44.91,c= 58.09 Å, α = 97.62, β = 99.10, γ = 94.09°, and diffracted X-rays to 1.6 Å resolution. The structure was determined by molecular replacement and refined to 1.65 Å resolution. The asymmetric unit contains one molecule of UIC2/Fab, which exhibits a positively charged antigen-binding surface, suggesting that it might recognize an oppositely charged extracellular epitope of P-gp.

Evidence for ligand and/or receptor-specific mechanisms of internalization and processing in cultured H35 hepatoma cells

International Nuclear Information System (INIS)

Goldberg, R.I.; Smith, R.M.; Jarett, L.

1987-01-01

Total cell associated (TC) and intracellularly accumulated (IC) 125 I-labeled insulin (INS) or α-2-macroglobulin (α2M) were assessed in cultured H35 hepatoma cells which were preincubated with various agents. Cytochalasin D or sodium azide, which affect microfilament- or energy-dependent receptor internalization, had no significant effects on INS TC or IC but each decreased α2M TC and IC to 50-75% of control. Monensin and chloroquine, acidotrophic agents, each increased INS TC and IC to 150-300% of control yet decreased TC and IC of α2M to 20-50% of control. Only leupeptin, a lysosomal protease inhibitor, caused an increase in both INS and α2M TC and IC. These data suggest significant differences exist in the biochemical regulation or structural routes of INS and α2M receptors and/or receptor-ligand complexes in their (1) internalization, (2) processing in acidic organelles, (3) recycling to the cell surface or in combinations of the above. Biochemical and ultrastructural studies are being performed on the H35 hepatoma cell which will characterize the processing of INS and α2M receptors and provide an explanation for the differences observed

Border Malaria Associated with Multidrug Resistance on Thailand-Myanmar and Thailand-Cambodia Borders: Transmission Dynamic, Vulnerability, and Surveillance

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Adisak Bhumiratana

2013-01-01

Full Text Available This systematic review elaborates the concepts and impacts of border malaria, particularly on the emergence and spread of Plasmodium falciparum and Plasmodium vivax multidrug resistance (MDR malaria on Thailand-Myanmar and Thailand-Cambodia borders. Border malaria encompasses any complex epidemiological settings of forest-related and forest fringe-related malaria, both regularly occurring in certain transmission areas and manifesting a trend of increased incidence in transmission prone areas along these borders, as the result of interconnections of human settlements and movement activities, cross-border population migrations, ecological changes, vector population dynamics, and multidrug resistance. For regional and global perspectives, this review analyzes and synthesizes the rationales pertaining to transmission dynamics and the vulnerabilities of border malaria that constrain surveillance and control of the world’s most MDR falciparum and vivax malaria on these chaotic borders.

The oncoprotein HBXIP suppresses gluconeogenesis through modulating PCK1 to enhance the growth of hepatoma cells.

Science.gov (United States)

Shi, Hui; Fang, Runping; Li, Yinghui; Li, Leilei; Zhang, Weiying; Wang, Huawei; Chen, Fuquan; Zhang, Shuqin; Zhang, Xiaodong; Ye, Lihong

2016-11-28

Hepatitis B X-interacting protein (HBXIP) as an oncoprotein plays crucial roles in the development of cancer, involving glucose metabolism reprogramming. In this study, we are interested in whether the oncoprotein HBXIP is involved in the modulation of gluconeogenesis in liver cancer. Here, we showed that the expression level of phosphoenolpyruvate carboxykinase (PCK1), a key enzyme of gluconeogenesis, was lower in clinical hepatocellular carcinoma (HCC) tissues than that in normal tissues. Mechanistically, HBXIP inhibited the expression of PCK1 through down-regulating transcription factor FOXO1 in hepatoma cells, and up-regulated miR-135a targeting the 3'UTR of FOXO1 mRNA in the cells. In addition, HBXIP increased the phosphorylation levels of FOXO1 protein by activating PI3K/Akt pathway, leading to the export of FOXO1 from nucleus to cytoplasm. Strikingly, over-expression of PCK1 could abolish the HBXIP-promoted growth of hepatoma cells in vitro and in vivo. Thus, we conclude that the oncoprotein HBXIP is able to depress the gluconeogenesis through suppressing PCK1 to promote hepatocarcinogenesis, involving miR-135a/FOXO1 axis and PI3K/Akt/p-FOXO1 pathway. Our finding provides new insights into the mechanism by which oncoprotein HBXIP modulates glucose metabolism reprogramming in HCC. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Multidrug-resistant tuberculosis and migration to Europe

DEFF Research Database (Denmark)

Hargreaves, S.; Lönnroth, K.; Nellums, L. B.

2017-01-01

Multidrug-resistant tuberculosis (MDR-TB) in low-incidence countries in Europe is more prevalent among migrants than the native population. The impact of the recent increase in migration to EU and EEA countries with a low incidence of TB (

MiR-520b suppresses proliferation of hepatoma cells through targeting ten-eleven translocation 1 (TET1) mRNA

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weiying; Lu, Zhanping; Gao, Yuen [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin (China); Ye, Lihong [State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin (China); Song, Tianqiang, E-mail: tjchi@hotmai.com [Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin (China); Zhang, Xiaodong, E-mail: zhangxd@nankai.edu.cn [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin (China)

2015-05-08

Accumulating evidence indicates that microRNAs are able to act as oncogenes or tumor suppressor genes in human cancer. We previously reported that miR-520b was down-regulated in hepatocellular carcinoma (HCC) and its deregulation was involved in hepatocarcinogenesis. In the present study, we report that miR-520b suppresses cell proliferation in HCC through targeting the ten-eleven translocation 1 (TET1) mRNA. Notably, we identified that miR-520b was able to target 3′-untranslated region (3′UTR) of TET1 mRNA by luciferase reporter gene assays. Then, we revealed that miR-520b was able to reduce the expression of TET1 at the levels of mRNA and protein using reverse transcription-polymerase chain reaction and Western blotting analysis. In terms of function, 5-ethynyl-2-deoxyuridine (EdU) incorporation and colony formation assays demonstrated that the forced miR-520b expression remarkably inhibited proliferation of hepatoma cells, but TET1 overexpression could rescue the inhibition of cell proliferation mediated by miR-520b. Furthermore, anti-miR-520b enhanced proliferation of hepatoma cells, whereas silencing of TET1 abolished anti-miR-520b-induced acceleration of cell proliferation. Then, we validated that the expression levels of miR-520b were negatively related to those of TET1 mRNA in clinical HCC tissues. Thus, we conclude that miR-520b depresses proliferation of liver cancer cells through targeting 3′UTR of TET1 mRNA. Our finding provides new insights into the mechanism of hepatocarcinogenesis. - Highlights: • TET1 is a novel target gene of miR-520b. • TET1 is upregulated in clinical HCC tissues. • MiR-520b is negatively correlated with TET1 in clinical HCC tissues. • MiR-520b depresses the proliferation of HCC cells through targeting TET1 mRNA.

Antimicrobial Activity of Actinomycetes Against Multidrug Resistant ...

African Journals Online (AJOL)

Antimicrobial Activity of Actinomycetes Against Multidrug Resistant Staphylococcus aureus, E. coli and Various Other Pathogens. ... Purpose: The rapid emergence of drug resistance among pathogenic bacteria, especially multidrugresistant bacteria, underlines the need to look for new antibiotics. Methods: In the present ...

Antibacterial activity of local herbs collected from Murree (Pakistan) against multi-drug resistant Klebsiella pneumonae, E. coli and methyciline resistant Staphylococcus aureus.

Science.gov (United States)

Mansoor, Qaisar; Shaheen, Saira; Javed, Uzma; Shaheen, Uzma; Iqrar, Irum; Ismail, Muhammad

2013-07-01

Exploring healing power in plants emerged in prehistory of human civilization. Sustaining good health has been achieved over the millions of years by use of plant products in various traditional sockets. A major contribution of medicinal plants to health care systems is their limitless possession of bioactive components that stimulate explicit physiological actions. Luckily Pakistan is blessed with huge reservoir of plants with medicinal potential and some of them; we focused in this study for their medicinal importance.In this study we checked the antibacterial activity inherent in Ricinus communis, Solanum nigrum, Dodonaea viscose and Berberis lyceum extracts for multidrug resistance bacterial strains Klebsiella pneumonae, E. coli and methyciline resistant Staphylococcus aureus. MRSA showed sensitivity for Ricinus communis. Multidrug resistant Klebsiella pneumonae was sensitive with Pine roxburgii and Ricinus communis but weakly susceptible for Solanum nigrum. Multidrug resistant E. coli was resistant to all plant extracts. Treatment of severe infections caused by the bacterial strains used in this study with Ricinus communis, Pine roxburgii and Solanum nigrum can lower the undesired side effects of synthetic medicine and also reduce the economic burden.

Expression of Raf kinase inhibitor protein in human hepatoma tissues by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight methods.

Science.gov (United States)

Tsao, D A; Shiau, Y F; Tseng, C S; Chang, H R

2016-01-01

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. To reduce the mortality and improve the effectiveness of therapy, it is important to search for changes in tumor-specific biomarkers whose function may involve in disease progression and which may be useful as potential therapeutic targets. Materials and Mehtods: In this study, we use two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to observe proteome alterations of 12 tissue pairs isolated from HCC patients: Normal and tumorous tissue. Comparing the tissue types with each other, 40 protein spots corresponding to fifteen differentially expressed between normal and cancer part of HCC patients. Raf kinase inhibitor protein (RKIP), an inhibitor of Raf-mediated activation of mitogen-activated protein kinase/extracellular signal-regulated kinase, may play an important role in cancer metastasis and cell proliferation and migration of human hepatoma cells. RKIP may be considered as a marker for HCC, because its expression level changes considerably in HCC compared with normal tissue. In addition, we used the methods of Western blotting and real time-polymerase chain reaction to analysis the protein expression and gene expression of RKIP. The result showed RKIP protein and gene expression in tumor part liver tissues of HCC patient is lower than peritumorous non-neoplastic liver tissue of the corresponding HCC samples. These results strongly suggest that RKIP may be considered to be a marker for HCC and RKIP are down-regulated in liver cancer cell.

Mouse ATP-Binding Cassette (ABC) Transporters Conferring Multi-Drug Resistance

Science.gov (United States)

Shuaizhang, L I; Zhang, Wen; Yin, Xuejiao; Xing, Shilai; Xie, Qunhui; Cao, Zhengyu; Zhao, Bin

2015-04-28

The ABC (ATP-binding cassette) transporter is one of the largest and most ancient protein families with members functioning from protozoa to human. The resistance of cancer and tumor cells to anticancer drugs is due to the over-expression of some ABC transporters, which may finally lead to chemotherapy failure. The mouse ABC transporters are classified into seven subfamilies by phylogenetic analysis. The mouse ABC transporter gene, alias, chromosomal location and function have been determined. Within the ABC super-family, the MDR transporters (Abcb1, Abcc1, Abcg2) in mouse models have been proved to be valuable to investigate the biochemistry and physiological functions. This review concentrates on the multidrug resistance of mouse ABC transporters in cancer and tumor cells.

A Novel Docetaxel-Loaded Poly (ɛ-Caprolactone)/Pluronic F68 Nanoparticle Overcoming Multidrug Resistance for Breast Cancer Treatment

Science.gov (United States)

Mei, Lin; Zhang, Yangqing; Zheng, Yi; Tian, Ge; Song, Cunxian; Yang, Dongye; Chen, Hongli; Sun, Hongfan; Tian, Yan; Liu, Kexin; Li, Zhen; Huang, Laiqiang

2009-12-01

Multidrug resistance (MDR) in tumor cells is a significant obstacle to the success of chemotherapy in many cancers. The purpose of this research is to test the possibility of docetaxel-loaded poly (ɛ-caprolactone)/Pluronic F68 (PCL/Pluronic F68) nanoparticles to overcome MDR in docetaxel-resistance human breast cancer cell line. Docetaxel-loaded nanoparticles were prepared by modified solvent displacement method using commercial PCL and self-synthesized PCL/Pluronic F68, respectively. PCL/Pluronic F68 nanoparticles were found to be of spherical shape with a rough and porous surface. The nanoparticles had an average size of around 200 nm with a narrow size distribution. The in vitro drug release profile of both nanoparticle formulations showed a biphasic release pattern. There was an increased level of uptake of PCL/Pluronic F68 nanoparticles in docetaxel-resistance human breast cancer cell line, MCF-7 TAX30, when compared with PCL nanoparticles. The cytotoxicity of PCL nanoparticles was higher than commercial Taxotere® in the MCF-7 TAX30 cell culture, but the differences were not significant ( p > 0.05). However, the PCL/Pluronic F68 nanoparticles achieved significantly higher level of cytotoxicity than both of PCL nanoparticles and Taxotere® ( p < 0.05), indicating docetaxel-loaded PCL/Pluronic F68 nanoparticles could overcome multidrug resistance in human breast cancer cells and therefore have considerable potential for treatment of breast cancer.

Drug accumulation in the presence of the multidrug resistance pump

DEFF Research Database (Denmark)

Ayesh, S; Litman, Thomas; Stein, W D

1997-01-01

We studied the interaction between the multidrug transporter, P-glycoprotein, and two compounds that interact with it: vinblastine, a classical substrate of the pump, and verapamil, a classical reverser. Steady-state levels of accumulation of these two drugs were determined in a multidrug resistant...... P388 leukemia cell line, P388/ADR. The time course of accumulation of these drugs, and the effect of energy starvation and the presence of chloroquine on the level of their steady-state accumulation were quite disparate. Vinblastine inhibited the accumulation of verapamil whereas it enhanced...

MarA-like regulator of multidrug resistance in Yersinia pestis.

Science.gov (United States)

Udani, Rupa A; Levy, Stuart B

2006-09-01

MarA47(Yp) from Yersinia pestis, showing 47% identity to Escherichia coli MarA in its N terminus, caused resistance to antibiotics and to organic solvents when expressed in both E. coli and Y. pestis. Resistance was linked to increased expression of the AcrAB multidrug efflux pump. In four of five spontaneous multidrug-resistant mutants of Y. pestis independently selected by growth on tetracycline, the marA47(Yp) gene was overexpressed. The findings suggest that marA47(Yp) is a marA ortholog in Y. pestis.

Multidrug Resistant Acinetobacter Infection and Their Antimicrobial ...

African Journals Online (AJOL)

Background: Acinetobacter baumannii, a non-glucose fermenting Gram negative bacillus, has emerged in the last three decades as a major etiological agent of hospital-associated infections giving rise to significant morbidity and mortality particularly in immunocompromised patients. Multidrug resistant A. baumannii ...

Protection of betulin against cadmium-induced apoptosis in hepatoma cells

International Nuclear Information System (INIS)

Oh, Seon-Hee; Choi, Jeong-Eun; Lim, Sung-Chul

2006-01-01

The protective effects of betulin (BT) against cadmium (Cd)-induced cytotoxicity have been previously reported. However, the mechanisms responsible for these protective effects are unclear. Therefore, this study investigated the mechanisms responsible for the protection of BT against Cd-induced cytotoxicity in human hepatoma cell lines. The protection of BT against Cd cytotoxicity was more effective in the HepG2 than in the Hep3B cells. The protection of BT on Cd-induced cytotoxicity in the HepG2 cells appeared to be related to the inhibition of apoptosis, as determined by PI staining and DNA fragmentation analysis. The anti-apoptosis exerted by BT involved the blocking of Cd-induced reactive oxygen species (ROS) generation, the abrogation of the Cd-induced Fas upregulation, the blocking of caspase-8-dependent Bid activation, and subsequent inhibition of mitochondrial pathway. The BT pretreatment did not affect the p21 and p53 expression levels, when compared with those of the treated cells with Cd alone. BT induced the transient S phase arrest at an early stage and the G /G 1 arrest at a relatively late stage, but it did not observe the sub-G1 apoptotic peak. In the Hep3B cells, Cd did not induce ROS generation. The BT pretreatment partially inhibited the Cd-induced apoptosis, which was related with the incomplete blockage in caspase-9 or -3 activation, as well as in Bax activation. Taken together, it was found that Cd can induce apoptosis via the Fas-dependent and -independent apoptosis pathways. However, the observed protective effects of BT were clearly more sensitive to Fas-expressing HepG2 cells than to Fas-deficient Hep3B cells

Hepatocyte specific expression of human cloned genes

Energy Technology Data Exchange (ETDEWEB)

Cortese, R

1986-01-01

A large number of proteins are specifically synthesized in the hepatocyte. Only the adult liver expresses the complete repertoire of functions which are required at various stages during development. There is therefore a complex series of regulatory mechanisms responsible for the maintenance of the differentiated state and for the developmental and physiological variations in the pattern of gene expression. Human hepatoma cell lines HepG2 and Hep3B display a pattern of gene expression similar to adult and fetal liver, respectively; in contrast, cultured fibroblasts or HeLa cells do not express most of the liver specific genes. They have used these cell lines for transfection experiments with cloned human liver specific genes. DNA segments coding for alpha1-antitrypsin and retinol binding protein (two proteins synthesized both in fetal and adult liver) are expressed in the hepatoma cell lines HepG2 and Hep3B, but not in HeLa cells or fibroblasts. A DNA segment coding for haptoglobin (a protein synthesized only after birth) is only expressed in the hepatoma cell line HepG2 but not in Hep3B nor in non hepatic cell lines. The information for tissue specific expression is located in the 5' flanking region of all three genes. In vivo competition experiments show that these DNA segments bind to a common, apparently limiting, transacting factor. Conventional techniques (Bal deletions, site directed mutagenesis, etc.) have been used to precisely identify the DNA sequences responsible for these effects. The emerging picture is complex: they have identified multiple, separate transcriptional signals, essential for maximal promoter activation and tissue specific expression. Some of these signals show a negative effect on transcription in fibroblast cell lines.

Virulence and genomic feature of multidrug resistant Campylobacter jejuni isolated from broiler chicken

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Haihong Hao

2016-10-01

Full Text Available The aim of this study was to reveal the molecular mechanism involved in multidrug resistance and virulence of Campylobacter jejuni isolated from broiler chickens. The virulence of six multidrug resistant C. jejuni was determined by in vitro and in vivo methods. The de novo whole genome sequencing technology and molecular biology methods were used to analyze the genomic features associated with the multidrug resistance and virulence of a selected isolate (C. jejuni 1655. The comparative genomic analyses revealed a large number of single nucleotide polymorphisms, deletions, rearrangements, and inversions in C. jejuni 1655 compared to reference C. jejuni genomes. The co-emergence of Thr-86-Ile mutation in gyrA gene, A2075G mutation in 23S rRNA gene, tetO, aphA and aadE genes and pTet plasmid in C. jejuni 1655 contributed its multidrug resistance to fluoroquinolones, macrolides, tetracycline and aminoglycosides. The combination of multiple virulence genes may work together to confer the relative higher virulence in C. jejuni 1655. The co-existence of mobile gene elements (e.g. pTet and CRISPR-Cas system in C. jejuni 1655 may play an important role in the gene transfer and immune defense. The present study provides basic information of phenotypic and genomic features of C. jejuni 1655, a strain recently isolated from a chicken displaying multidrug resistance and relatively high level of virulence.

Multidrug resistance 1 gene polymorphisms may determine Crohn's disease behavior in patients from Rio de Janeiro

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Ana Teresa P. Carvalho

2014-01-01

Full Text Available OBJECTIVES: Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro. METHODS: We analyzed 123 Crohn's disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T. In particular, the genotype frequencies of Crohn's disease and ulcerative colitis patients were analyzed. Genotype-phenotype associations with major clinical characteristics were established, and estimated risks were calculated for the mutations. RESULTS: No significant difference was observed in the genotype frequencies of the multidrug resistance 1 G2677T/A and C3435T polymorphisms between Crohn's disease and ulcerative colitis patients. In contrast, the C1236T polymorphism was significantly more common in Crohn's disease than in ulcerative colitis (p = 0.047. A significant association was also found between the multidrug resistance 1 C3435T polymorphism and the stricturing form of Crohn's disease (OR: 4.13; p = 0.009, whereas no association was found with penetrating behavior (OR: 0.33; p = 0.094. In Crohn's disease, a positive association was also found between the C3435T polymorphism and corticosteroid resistance/refractoriness (OR: 4.14; p = 0.010. However, no significant association was found between multidrug resistance 1 gene polymorphisms and UC subphenotypic categories. CONCLUSION: The multidrug resistance 1 gene polymorphism C3435T is associated with the stricturing phenotype and an inappropriate response to therapy in Crohn's disease. This association with Crohn's disease may support additional pathogenic roles for the multidrug resistance 1 gene in regulating gut

Phosphorus NMR of isolated perfused morris hepatomas

International Nuclear Information System (INIS)

Graham, R.A.; Meyer, R.A.; Brown, T.R.; Sauer, L.A.

1986-01-01

The authors are developing techniques for the study of perfused solid tumors by NMR. Tissue-isolated solid hepatomas were grown to 1-2 cm diameter as described previously. The arterial supply was isolated and the tumors perfused (0.5 - 1.0 ml/min) in vitro at 25 C with a 15% suspension of red blood cells in Krebs-Henseliet solution. 31 P-NMR spectra were acquired at 162 MHz in a specially-designed NMR probe using a solenoidal coil. Intracellular pH (monitored from the chemical shift of inorganic phosphate) and ATP levels were stable for up to 6 hrs during perfusion. During 30 min of global ischemia, ATP decreased by 75% and pH fell from 7.0 to 6.7. These changes were reversed by 1 hr reperfusion. In addition to ATP and phosphate, the spectra included a large resonance due to phosphomonoesters, as well as peaks consistent with glycerylphosphocholine, glyceryl-phosphoethanolamine, phosphocreatine, NAD, and UDPG. However, the most novel feature of the spectra was the presence of an unidentified peak in the phosphonate region (+ 16.9 ppm). The peak was not present in spectra of muscle, liver, brain, kidney, or fat tissues excised from the same animals. They are presently attempting to identify the compound that gives rise to this peak and to establish its metabolic origin

Multidrug-Resistant Candida: Epidemiology, Molecular Mechanisms, and Treatment.

Science.gov (United States)

Arendrup, Maiken Cavling; Patterson, Thomas F

2017-08-15

Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients. Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites of infection/colonization, drug sequestration in the biofilm matrix, and, in the setting of outbreaks, suboptimal infection control. Moreover, recent research suggests that DNA mismatch repair gene mutations may facilitate acquisition of resistance mutations in C. glabrata specifically. Diagnosis of antifungal-resistant Candida infections is critical to the successful management of patients with these infections. Reduction of unnecessary use of antifungals via antifungal stewardship is critical to limit multidrug resistance emergence. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

The application of 99Tcm-MIBI scintimammography to diagnose multidrug resistance of breast cancer

International Nuclear Information System (INIS)

Cheng Bing

2002-01-01

The author discussed the main mechanism of multidrug resistance of breast cancer tissues, and the correlation between technetium-99m sestamibi ( 99 Tc m -MIBI) breast imaging results, with the expression of drug resistance proteins P-glycoprotein and glutathione-S-transferase-π in human breast cancer. Through not all the results reported before matched each other, as a kind of a noninvasive simple functional test imaging technology in vitro, SPECT can be used to diagnose P-glycoprotein expression in breast cancer, and can be used to predict chemotherapy response

Solutol HS 15, nontoxic polyoxyethylene esters of 12-hydroxystearic acid, reverses multidrug resistance.

Science.gov (United States)

Coon, J S; Knudson, W; Clodfelter, K; Lu, B; Weinstein, R S

1991-02-01

A recently developed non-ionic surfactant called Solutol HS 15 (poly-oxyethylene esters of 12-hydroxystearic acid), with low toxicity in vivo, was shown to reverse completely the multidrug resistance of KB 8-5 and KB 8-5-11 human epidermoid carcinoma cells in vitro but did not potentiate drug toxicity in drug-sensitive KB 3-1 cells. At a concentration of 10% of its own IC50 (mean concentration of drug that causes 50% inhibition of cell growth compared to controls), Solutol HS 15 produced a 35-, 28-, and 42-fold reduction in the resistance of KB 8-5-11 cells to colchicine, vinblastine, and doxorubicin, respectively. Solutol HS 15 was relatively much more potent than the prototypic reversing agent, verapamil, for reversing colchicine resistance, compared to the ability of each agent to reverse colchicine resistance, compared to the ability of each agent to reverse vinblastine resistance. Like verapamil, Solutol HS 15 promoted a 50-fold accumulation of rhodamine 123 in KB 8-5-11 cells, as measured by flow cytometry. Also, Solutol HS 15 and verapamil reduced the efflux of rhodamine 123 from KB 8-5-11 cells previously loaded with rhodamine 123 to a similar low rate. Solutol HS 15 did not affect the transport of alanine or glucose into KB 8-5-11 cells, indicating that its effect upon membrane active transport is not entirely nonspecific. Considering their different structure and different relative potency for reversing colchicine resistance, Solutol HS 15 and verapamil probably reverse multidrug resistance by different mechanisms. Solutol HS 15 merits consideration as a potential therapeutic agent because of its effectiveness for reversing multidrug resistance in vitro and its low toxicity in vivo.

H32, a non-quinone sulfone analog of vitamin K3, inhibits human hepatoma cell growth by inhibiting Cdc25 and activating ERK.

Science.gov (United States)

Kar, Siddhartha; Wang, Meifang; Ham, Seung Wook; Carr, Brian I

2006-10-01

We previously synthesized a K-vitamin derivative, Cpd 5, which was a potent growth inhibitor of human tumor cells, including Hep3B hepatoma cells. However, being a quinone compound, Cpd 5 has the potential for generating toxic reactive oxygen species (ROS). We therefore synthesized a nonquinone sulfone derivative, H32, which has a sufone group substituting the quinone. The IC50 of H32 for Hep3B cells was found to be 2.5 microM, which was 2.5 and 3.2 times more potent than Cpd 5 and vitamin K3 respectively. It induced apoptosis in Hep3B cells but did not generate ROS when compared to Cpd 5. Interestingly, under similar culture conditions, normal rat hepatocytes were 14-fold more and 7-fold more resistant to the growth inhibitory effects of H32 than Hep3B and PLC/PRF5 cells respectively. H32 preferentially inhibited the activities of the cell cycle controlling Cdc25A phosphatase likely by binding to its catalytic cysteine. As a consequence, it induced inhibitory tyrosine phosphorylation of the Cdc25 substrate kinases Cdk2 and Cdk4 in Hep3B cells and the cells undergo an arrest in the G1 phase of the cell cycle. H32 also induced persistent phosphorylation of the MAPK protein ERK1/2, but marginal JNK1/2 and p38 phosphorylation. The ERK inhibitor U0126, added at least 30 min prior to H32, antagonized the growth inhibition induced by H32. However, the JNK and p38 inhibitors, JNKI-II and SB203580, were not able to antagonize H32 induced growth inhibition. Thus, H32 differentially inhibited growth of normal and liver tumor cells by preferentially inhibiting the actions of Cdc25 phosphatases and inducing persistent ERK phosphorylation.

Multidrug-resistant tuberculosis, Somalia, 2010-2011.

Science.gov (United States)

Sindani, Ireneaus; Fitzpatrick, Christopher; Falzon, Dennis; Suleiman, Bashir; Arube, Peter; Adam, Ismail; Baghdadi, Samiha; Bassili, Amal; Zignol, Matteo

2013-03-01

In a nationwide survey in 2011, multidrug-resistant tuberculosis (MDR TB) was found in 5.2% and 40.8% of patients with new and previously treated TB, respectively. These levels of drug resistance are among the highest ever documented in Africa and the Middle East. This finding presents a serious challenge for TB control in Somalia.

Drug efflux proteins in multidrug resistant bacteria

NARCIS (Netherlands)

vanVeen, HW; Konings, WN

Bacteria contain an array of transport proteins in their cytoplasmic membrane. Many of these proteins play an important role in conferring resistance to toxic compounds. The multidrug efflux systems encountered in prokaryotic cells are very similar to those observed in eukaryotic cells. Therefore, a

Worldwide Endemicity of a Multidrug-Resistant Staphylococcus capitis Clone Involved in Neonatal Sepsis.

Science.gov (United States)

Butin, Marine; Martins-Simões, Patricia; Rasigade, Jean-Philippe; Picaud, Jean-Charles; Laurent, Frédéric

2017-03-01

A multidrug-resistant Staphylococcus capitis clone, NRCS-A, has been isolated from neonatal intensive care units in 17 countries throughout the world. S. capitis NRCS-A prevalence is high in some neonatal intensive care units in France. These data highlight the worldwide endemicity and epidemiologic relevance of this multidrug-resistant, coagulase-negative staphylococci clone.

Epidemiologic analysis: Prophylaxis and multidrug-resistance in surgery

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H. Solís-Téllez

2017-04-01

Conclusions: The prophylactic guidelines are not strictly adhered to in our environment. There was a significant association between the development of nosocomial infections from multidrug-resistant germs and admission to the intensive care unit.

Potential strategies for the eradication of multidrug-resistant Gram-negative bacterial infections.

Science.gov (United States)

Huwaitat, Rawan; McCloskey, Alice P; Gilmore, Brendan F; Laverty, Garry

2016-07-01

Antimicrobial resistance is one of the leading threats to society. The increasing burden of multidrug-resistant Gram-negative infection is particularly concerning as such bacteria are demonstrating resistance to nearly all currently licensed therapies. Various strategies have been hypothesized to treat multidrug-resistant Gram-negative infections including: targeting the Gram-negative outer membrane; neutralization of lipopolysaccharide; inhibition of bacterial efflux pumps and prevention of protein folding. Silver and silver nanoparticles, fusogenic liposomes and nanotubes are potential strategies for extending the activity of licensed, Gram-positive selective, antibiotics to Gram-negatives. This may serve as a strategy to fill the current void in pharmaceutical development in the short term. This review outlines the most promising strategies that could be implemented to solve the threat of multidrug-resistant Gram-negative infections.

Complete genome sequence, lifestyle, and multi-drug resistance of the human pathogen Corynebacterium resistens DSM 45100 isolated from blood samples of a leukemia patient

Science.gov (United States)

2012-01-01

Background Corynebacterium resistens was initially recovered from human infections and recognized as a new coryneform species that is highly resistant to antimicrobial agents. Bacteremia associated with this organism in immunocompromised patients was rapidly fatal as standard minocycline therapies failed. C. resistens DSM 45100 was isolated from a blood culture of samples taken from a patient with acute myelocytic leukemia. The complete genome sequence of C. resistens DSM 45100 was determined by pyrosequencing to identify genes contributing to multi-drug resistance, virulence, and the lipophilic lifestyle of this newly described human pathogen. Results The genome of C. resistens DSM 45100 consists of a circular chromosome of 2,601,311 bp in size and the 28,312-bp plasmid pJA144188. Metabolic analysis showed that the genome of C. resistens DSM 45100 lacks genes for typical sugar uptake systems, anaplerotic functions, and a fatty acid synthase, explaining the strict lipophilic lifestyle of this species. The genome encodes a broad spectrum of enzymes ensuring the availability of exogenous fatty acids for growth, including predicted virulence factors that probably contribute to fatty acid metabolism by damaging host tissue. C. resistens DSM 45100 is able to use external L-histidine as a combined carbon and nitrogen source, presumably as a result of adaptation to the hitherto unknown habitat on the human skin. Plasmid pJA144188 harbors several genes contributing to antibiotic resistance of C. resistens DSM 45100, including a tetracycline resistance region of the Tet W type known from Lactobacillus reuteri and Streptococcus suis. The tet(W) gene of pJA144188 was cloned in Corynebacterium glutamicum and was shown to confer high levels of resistance to tetracycline, doxycycline, and minocycline in vitro. Conclusions The detected gene repertoire of C. resistens DSM 45100 provides insights into the lipophilic lifestyle and virulence functions of this newly recognized

Multidrug resistant bacteria isolated from septic arthritis in horses

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Rodrigo G. Motta

Full Text Available ABSTRACT: Septic arthritis is a debilitating joint infectious disease of equines that requires early diagnosis and immediate therapeutic intervention to prevent degenerative effects on the articular cartilage, as well as loss of athletic ability and work performance of the animals. Few studies have investigated the etiological complexity of this disease, as well as multidrug resistance of isolates. In this study, 60 horses with arthritis had synovial fluid samples aseptically collected, and tested by microbiological culture and in vitro susceptibility test (disk diffusion using nine antimicrobials belonging to six different pharmacological groups. Bacteria were isolated in 45 (75.0% samples, as follows: Streptococcus equi subsp. equi (11=18.3%, Escherichia coli (9=15.0%, Staphylococcus aureus (6=10.0%, Streptococcus equi subsp. zooepidemicus (5=8.3%, Staphylococcus intermedius (2=3.3%, Proteus vulgaris (2=3.3%, Trueperella pyogenes (2=3.3%, Pseudomonas aeruginosa (2=3.3%, Klebsiella pneumoniae (1=1.7%, Rhodococcus equi (1=1.7%, Staphylococcus epidermidis (1=1.7%, Klebsiella oxytoca (1=1.7%, Nocardia asteroides (1=1.7%, and Enterobacter cloacae (1=1.7%. Ceftiofur was the most effective drug (>70% efficacy against the pathogens in the disk diffusion test. In contrast, high resistance rate (>70% resistance was observed to penicillin (42.2%, enrofloxacin (33.3%, and amikacin (31.2%. Eleven (24.4% isolates were resistant to three or more different pharmacological groups and were considered multidrug resistant strains. The present study emphasizes the etiological complexity of equine septic arthritis, and highlights the need to institute treatment based on the in vitro susceptibility pattern, due to the multidrug resistance of isolates. According to the available literature, this is the first report in Brazil on the investigation of the etiology. of the septic arthritis in a great number of horses associated with multidrug resistance of the isolates.

Plasmid Transfer of Plasminogen K1-5 Reduces Subcutaneous Hepatoma Growth by Affecting Inflammatory Factors

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Lea A. Koch

2014-01-01

Full Text Available There is evidence that plasminogen K1-5 (PlgK1-5 directly affects tumour cells and inflammation. Therefore, we analysed if PlgK1-5 has immediate effects on hepatoma cells and inflammatory factors in vitro and in vivo. In vitro, effects of plasmid encoding PlgK1-5 (pK1-5 on Hepa129, Hepa1-6, and HuH7 cell viability, apoptosis, and proliferation as well as VEGF and TNF-alpha expression and STAT3-phosphorylation were investigated. In vivo, tumour growth, proliferation, vessel density, and effects on vascular endothelial growth factor (VEGF and tumour necrosis factor alpha (TNF-alpha expression were examined following treatment with pK1-5. In vivo, pK1-5 halved cell viability; cell death was increased by up to 15% compared to the corresponding controls. Proliferation was not affected. VEGF, TNF-alpha, and STAT3-phosphorylation were affected following treatment with pK1-5. In vivo, ten days after treatment initiation, pK1-5 reduced subcutaneous tumour growth by 32% and mitosis by up to 77% compared to the controls. Vessel density was reduced by 50%. TNF-alpha levels in tumour and liver tissue were increased, whereas VEGF levels in tumours and livers were reduced after pK1-5 treatment. Taken together, plasmid gene transfer of PlgK1-5 inhibits hepatoma (cell growth not only by reducing vessel density but also by inducing apoptosis, inhibiting proliferation, and triggering inflammation.

A portable 3D printer system for the diagnosis and treatment of multidrug-resistant bacteria

OpenAIRE

Glatzel, Stefan; Hezwani, Mohammed; Kitson, Philip J.; Gromski, Piotr S.; Schürer, Sophie; Cronin, Leroy

2016-01-01

Summary: Multidrug-resistant bacteria are a major threat to human health, but broad-spectrum\\ud antibiotics are losing efficacy. There is a need to screen a given drug against\\ud a bacterial infection outside of the laboratory. To address this need, we have designed\\ud and built an inexpensive and easy-to-use 3D-printer-based system that\\ud allows easily readable quantitative tests for the performance of antibacterial\\ud drugs. The platform creates a sterile diagnostic device by using 3D prin...

Bacillus subtilis from Soybean Food Shows Antimicrobial Activity for Multidrug-Resistant Acinetobacter baumannii by Affecting the adeS Gene.

Science.gov (United States)

Wang, Tieshan; Su, Jianrong

2016-12-28

Exploring novel antibiotics is necessary for multidrug-resistant pathogenic bacteria. Because the probiotics in soybean food have antimicrobial activities, we investigated their effects on multidrug-resistant Acinetobacter baumannii . Nineteen multidrug-resistant A. baumannii strains were clinifcally isolated as an experimental group and 11 multidrug-sensitive strains as controls. The growth rates of all bacteria were determined by using the analysis for xCELLigence Real-Time Cell. The combination of antibiotics showed synergistic effects on the strains in the control group but no effect on the strains in the experimental group. Efflux pump gene adeS was absent in all the strains from the control group, whereas it exists in all the strains from the experimental group. Furthermore, all the strains lost multidrug resistance when an adeS inhibitor was used. One strain of probiotics isolated from soybean food showed high antimicrobial activity for multidrug-resistant A. baumannii . The isolated strain belongs to Bacillus subtilis according to 16S RNA analysis. Furthermore, E. coli showed multidrug resistance when it was transformed with the adeS gene from A. baumannii whereas the resistant bacteria could be inhibited completely by isolated Bacillus subtilis . Thus, probiotics from soybean food provide potential antibiotics against multidrug-resistant pathogenic bacteria.

Altered membrane permeability in multidrug resistant Escherichia ...

African Journals Online (AJOL)

The study was conducted with the objective of examining the outer membrane proteins and their involvement during the transport of β - lactams in multidrug resistant Escherichia coli isolated from extra-intestinal infections. Also, the response of gram negative bacterial biomembrane alteration was studied using extended ...

Carbohydrate linked organotin(IV) complexes as human topoisomerase Iα inhibitor and their antiproliferative effects against the human carcinoma cell line.

Science.gov (United States)

Khan, Rais Ahmad; Yadav, Shipra; Hussain, Zahid; Arjmand, Farukh; Tabassum, Sartaj

2014-02-14

Dimethyltin(IV) complexes with ethanolamine (1) and biologically significant N-glycosides (2 and 3) were designed and synthesized. The structural elucidation of complexes 1-3 was done using elemental and spectroscopic methods; in addition, complex 1 was studied by single crystal X-ray diffraction studies. The in vitro DNA binding profile of complexes 2 and 3 was carried out by employing different biophysical methods to ascertain the feasibility of glycosylated complexes. Further, the cleaving ability of 2 and 3 was investigated by the agarose gel electrophoretic mobility assay with supercoiled pBR322 DNA, and demonstrated significantly good nuclease activity. Furthermore, both the complexes exhibited significant inhibitory effects on the catalytic activity of human Topo I at lower concentration than standard drugs. Computer-aided molecular docking techniques were used to ascertain the mode and mechanism of action towards the molecular target DNA and Topo I. The cytotoxicity of 2 and 3 against human hepatoma cancer cells (Huh7) was evaluated, which revealed significant regression in cancerous cells as compared with the standard drug. The antiproliferative activities of 2 and 3 were tested against human hepatoma cancer cells (Huh7), and results showed significantly good activity. Additionally, to validate the remarkable antiproliferative activity of complexes 2 and 3, specific regulatory gene expression (MMP-2 and TGF-β) was obtained by real time PCR.

Tolerance response of multidrug-resistant Salmonella enterica strains to habituation to Origanum vulgare L. essential oil

Science.gov (United States)

Monte, Daniel F. M.; Tavares, Adassa G.; Albuquerque, Allan R.; Sampaio, Fábio C.; Oliveira, Tereza C. R. M.; Franco, Octavio L.; Souza, Evandro L.; Magnani, Marciane

2014-01-01

Multidrug-resistant Salmonella enterica isolates from human outbreaks or from poultry origin were investigated for their ability to develop direct-tolerance or cross-tolerance to sodium chloride, potassium chloride, lactic acid, acetic acid, and ciprofloxacin after habituation in subinhibitory amounts ( of the minimum inhibitory concentration – (MIC) and of the minimum inhibitory concentration – MIC) of Origanum vulgare L. essential oil (OVEO) at different time intervals. The habituation of S. enterica to OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by the modulation of MIC values. However, cells habituated to OVEO maintained or increased susceptibility to the tested antimicrobials agents, with up to fourfold double dilution decrease from previously determined MIC values. This study reports for the first time the non-inductive effect of OVEO on the acquisition of direct-tolerance or cross-tolerance in multidrug-resistant S. enterica strains to antimicrobial agents that are largely used in food preservation, as well as to CIP, the therapeutic drug of salmonellosis. PMID:25566231

CD81 Receptor Regions outside the Large Extracellular Loop Determine Hepatitis C Virus Entry into Hepatoma Cells

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Pia Banse

2018-04-01

Full Text Available Hepatitis C virus (HCV enters human hepatocytes using four essential entry factors, one of which is human CD81 (hCD81. The tetraspanin hCD81 contains a large extracellular loop (LEL, which interacts with the E2 glycoprotein of HCV. The role of the non-LEL regions of hCD81 (intracellular tails, four transmembrane domains, small extracellular loop and intracellular loop is poorly understood. Here, we studied the contribution of these domains to HCV susceptibility of hepatoma cells by generating chimeras of related tetraspanins with the hCD81 LEL. Our results show that non-LEL regions in addition to the LEL determine susceptibility of cells to HCV. While closely related tetraspanins (X. tropicalis CD81 and D. rerio CD81 functionally complement hCD81 non-LEL regions, distantly related tetraspanins (C. elegans TSP9 amd D. melanogaster TSP96F do not and tetraspanins with intermediate homology (hCD9 show an intermediate phenotype. Tetraspanin homology and susceptibility to HCV correlate positively. For some chimeras, infectivity correlates with surface expression. In contrast, the hCD9 chimera is fully surface expressed, binds HCV E2 glycoprotein but is impaired in HCV receptor function. We demonstrate that a cholesterol-coordinating glutamate residue in CD81, which hCD9 lacks, promotes HCV infection. This work highlights the hCD81 non-LEL regions as additional HCV susceptibility-determining factors.

The role of hypoxia response element in TGFβ-induced carbonic anhydrase IX expression in Hep3B human hepatoma cells

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Yildirim Hatice

2017-01-01

Full Text Available Carbonic anhydrase IX (CAIX is a hypoxia-regulated gene. It is over expressed in a variety of cancers, including hepatocellular cancer. Transforming growth factor β (TGFβ is considered to have an impact on cancer biology due to its important roles in cell proliferation and differentiation. The effect of the TGFβ on CAIX expression under hypoxia and the mechanism underlying the role of the hypoxia response element (HRE on this expression are unknown. In this study, we demonstrate that TGFβ upregulates CAIX expression under hypoxic conditions in the Hep3B hepatoma cell line, indicating that the mitogen-activated protein kinase (MAPK- and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K-signaling pathways might be responsible for this response. Site-directed mutagenesis of the HRE region in CAIX promoter reduced the TGFβ-induced CAIX promoter activity, pointing to the significance of HRE for this response. Up regulation of TGFβ-stimulated CAIX expression was consistent with the up regulation of promoter activity of five different truncated constructs of the CAIX promoter under hypoxia. Our findings show that the HRE region is critical for TGFβ-induced CAIX expression, which is mainly controlled by MAPK and PI3K pathways.

Dynamic MR imaging of hepatoma treated by transcatheter arterial embolization therapy

International Nuclear Information System (INIS)

Yamashita, Y.; Yoshimatsu, S.; Sumi, M.; Harada, M.; Takahashi, M.

1993-01-01

The effect of transcatheter arterial chemo-embolization theory (TACE) for hepatoma was evaluated with dynamic MR imaging with Gd-DTPA in 37 patients (44 tumors). TACE was performed using Lipiodol/cis-platinum and gelatin sponge (or microspheres) as an embolic material. All patients were examined with dynamic CT and MR imaging before and after treatment. On conventional spin echo images, changes of signal intensity after treatment varied regardless of presence of Lipiodol. Dynamic MR imaging revealed changes of tumor vascularity before and after treatment. On histologic correlation, areas of persistent tumor enhancement on dynamic MR imaging corresponded to areas of viable tumor cells while areas of nonenhancement corresponded to areas of necrosis. Dynamic MR imaging was superior in contrast resolution and was not influenced by the presence of Lipiodol compared with dynamic CT, and therefore residual viable tumors were better defined by dynamic MR imaging. (orig.)

Contribution of ketone bodies to cholesterogenesis in Morris hepatoma 7777 cells

International Nuclear Information System (INIS)

Hilderbrandt, L.; Elson, C.; Shrago, E.

1990-01-01

Cholesterol synthesis in neoplastic tissues is typically measured in incubations of minced tissue or tissue slices with 10 mM concentrations of individual substrates. Carbon incorporation into cholesterol from [ 14 C] labelled substrates by freshly isolated hepatoma cells was measured after one hour incubation with 10 mm single substrates. These observations were extended by measuring cholesterol synthesis supported by [ 14 C] substrates in a media containing a mixture of substrates at physiological concentrations: 5.0 mM glucose, 1.3 mM D(-)-3-hydroxybutyrate, 0.5 mM acetoacetate, 0.3 mM acetate, 0.3 mM oleate, 0.3 mM palmitate, 0.65 mM glutamine, 1.4 mM lactate and 0.1 mM pyruvate in Eagle's modified essential medium. Under single substrate conditions, the ketone bodies contribute substantially to cholesterogenesis. Estimates of the quantitative contribution of each substrate to total cholesterol synthesis are reported

The emergence and outbreak of multidrug-resistant typhoid fever in China.

Science.gov (United States)

Yan, Meiying; Li, Xinlan; Liao, Qiaohong; Li, Fang; Zhang, Jing; Kan, Biao

2016-06-22

Typhoid fever remains a severe public health problem in developing countries. The emergence of resistant typhoid, particularly multidrug-resistant typhoid infections, highlights the necessity of monitoring the resistance characteristics of this invasive pathogen. In this study, we report a typhoid fever outbreak caused by multidrug-resistant Salmonella enterica serovar Typhi strains with an ACSSxtT pattern. Resistance genes conferring these phenotypes were harbored by a large conjugative plasmid, which increases the threat of Salmonella Typhi and thus requires close surveillance for dissemination of strains containing such genes.

Vildagliptin and its metabolite M20.7 induce the expression of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells.

Science.gov (United States)

Asakura, Mitsutoshi; Karaki, Fumika; Fujii, Hideaki; Atsuda, Koichiro; Itoh, Tomoo; Fujiwara, Ryoichi

2016-10-19

Vildagliptin is a potent, orally active inhibitor of dipeptidyl peptidase-4 (DPP-4) for the treatment of type 2 diabetes mellitus. It has been reported that vildagliptin can cause hepatic dysfunction in patients. However, the molecular-mechanism of vildagliptin-induced liver dysfunction has not been elucidated. In this study, we employed an expression microarray to determine hepatic genes that were highly regulated by vildagliptin in mice. We found that pro-inflammatory S100 calcium-binding protein (S100) a8 and S100a9 were induced more than 5-fold by vildagliptin in the mouse liver. We further examined the effects of vildagliptin and its major metabolite M20.7 on the mRNA expression levels of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells. In HepG2 cells, vildagliptin, M20.7, and sitagliptin - another DPP-4 inhibitor - induced S100A9 mRNA. In HL-60 cells, in contrast, S100A8 and S100A9 mRNAs were significantly induced by vildagliptin and M20.7, but not by sitagliptin. The release of S100A8/A9 complex in the cell culturing medium was observed in the HL-60 cells treated with vildagliptin and M20.7. Therefore, the parental vildagliptin- and M20.7-induced release of S100A8/A9 complex from immune cells, such as neutrophils, might be a contributing factor of vildagliptin-associated liver dysfunction in humans.

Strategies to overcome or circumvent P-glycoprotein mediated multidrug resistance.

Science.gov (United States)

Yuan, Hongyu; Li, Xun; Wu, Jifeng; Li, Jinpei; Qu, Xianjun; Xu, Wenfang; Tang, Wei

2008-01-01

Cancer patients who receive chemotherapy often experience intrinsic or acquired resistance to a broad spectrum of chemotherapeutic agents. The phenomenon, termed multidrug resistance (MDR), is often associated with the over-expression of P-glycoprotein, a transmembrane protein pump, which can enhance efflux of a various chemicals structurally unrelated at the expense of ATP depletion, resulting in decrease of the intracellular cytotoxic drug accumulation. The MDR has been a big threaten to the human health and the war fight for it continues. Although several other mechanisms for MDR are elucidated in recent years, considerable efforts attempting to inverse MDR are involved in exploring P-glycoprotein modulators and suppressing P-glycoprotein expression. In this review, we will report on the recent advances in various strategies for overcoming or circumventing MDR mediated by P-glycoprotein.

Identification of antimicrobial resistance genes in multidrug-resistant clinical Bacteroides fragilis isolates by whole genome shotgun sequencing

DEFF Research Database (Denmark)

Sydenham, Thomas Vognbjerg; Sóki, József; Hasman, Henrik

2015-01-01

Bacteroides fragilis constitutes the most frequent anaerobic bacterium causing bacteremia in humans. The genetic background for antimicrobial resistance in B. fragilis is diverse with some genes requiring insertion sequence (IS) elements inserted upstream for increased expression. To evaluate whole...... genome shotgun sequencing as a method for predicting antimicrobial resistance properties, one meropenem resistant and five multidrug-resistant blood culture isolates were sequenced and antimicrobial resistance genes and IS elements identified using ResFinder 2.1 (http...

Hepatoma SK Hep-1 cells exhibit characteristics of oncogenic mesenchymal stem cells with highly metastatic capacity.

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Jong Ryeol Eun

Full Text Available SK Hep-1 cells (SK cells derived from a patient with liver adenocarcinoma have been considered a human hepatoma cell line with mesenchymal origin characteristics, however, SK cells do not express liver genes and exhibit liver function, thus, we hypothesized whether mesenchymal cells might contribute to human liver primary cancers. Here, we characterized SK cells and its tumourigenicity.We found that classical mesenchymal stem cell (MSC markers were presented on SK cells, but endothelial marker CD31, hematopoietic markers CD34 and CD45 were negative. SK cells are capable of differentiate into adipocytes and osteoblasts as adipose-derived MSC (Ad-MSC and bone marrow-derived MSC (BM-MSC do. Importantly, a single SK cell exhibited a substantial tumourigenicity and metastatic capacity in immunodefficient mice. Metastasis not only occurred in circulating organs such as lung, liver, and kidneys, but also in muscle, outer abdomen, and skin. SK cells presented greater in vitro invasive capacity than those of Ad-MSC and BM-MSC. The xenograft cells from subcutaneous and metastatic tumors exhibited a similar tumourigenicity and metastatic capacity, and showed the same relatively homogenous population with MSC characteristics when compared to parental SK cells. SK cells could unlimitedly expand in vitro without losing MSC characteristics, its tumuorigenicity and metastatic capacity, indicating that SK cells are oncogenic MSC with enhanced self-renewal capacity. We believe that this is the first report that human MSC appear to be transformed into cancer stem cells (CSC, and that their derivatives also function as CSCs.Our findings demonstrate that SK cells represent a transformation mechanism of normal MSC into an enhanced self-renewal CSC with metastasis capacity, SK cells and their xenografts represent a same relative homogeneity of CSC with substantial metastatic capacity. Thus, it represents a novel mechanism of tumor initiation, development and

Structure of the transcriptional regulator LmrR and its mechanism of multidrug recognition.

Science.gov (United States)

Madoori, Pramod Kumar; Agustiandari, Herfita; Driessen, Arnold J M; Thunnissen, Andy-Mark W H

2009-01-21

LmrR is a PadR-related transcriptional repressor that regulates the production of LmrCD, a major multidrug ABC transporter in Lactococcus lactis. Transcriptional regulation is presumed to follow a drug-sensitive induction mechanism involving the direct binding of transporter ligands to LmrR. Here, we present crystal structures of LmrR in an apo state and in two drug-bound states complexed with Hoechst 33342 and daunomycin. LmrR shows a common topology containing a typical beta-winged helix-turn-helix domain with an additional C-terminal helix involved in dimerization. Its dimeric organization is highly unusual with a flat-shaped hydrophobic pore at the dimer centre serving as a multidrug-binding site. The drugs bind in a similar manner with their aromatic rings sandwiched in between the indole groups of two dimer-related tryptophan residues. Multidrug recognition is facilitated by conformational plasticity and the absence of drug-specific hydrogen bonds. Combined analyses using site-directed mutagenesis, fluorescence-based drug binding and protein-DNA gel shift assays reveal an allosteric coupling between the multidrug- and DNA-binding sites of LmrR that most likely has a function in the induction mechanism.

Understanding institutional stakeholders’ perspectives on multidrug-resistant bacterial organism at the end of life: a qualitative study

Science.gov (United States)

Heckel, Maria; Herbst, Franziska A; Adelhardt, Thomas; Tiedtke, Johanna M; Sturm, Alexander; Stiel, Stephanie; Ostgathe, Christoph

2017-01-01

Background Information lacks about institutional stakeholders’ perspectives on management approaches of multidrug-resistant bacterial organism in end-of-life situations. The term “institutional stakeholder” includes persons in leading positions with responsibility in hospitals’ multidrug-resistant bacterial organism management. They have great influence on how strategies on multidrug-resistant bacterial organism management approaches in institutions of the public health system are designed. This study targeted institutional stakeholders’ individual perspectives on multidrug-resistant bacterial organism colonization or infection and isolation measures at the end of life. Methods Between March and December 2014, institutional stakeholders of two study centers, a German palliative care unit and a geriatric ward, were queried in semistructured interviews. Interviews were audiotaped, transcribed verbatim, and analyzed qualitatively with the aid of the software MAXQDA for qualitative data analysis using principles of Grounded Theory. In addition, two external stakeholders were interviewed to enrich data. Results Key issues addressed by institutional stakeholders (N=18) were the relevance of multidrug-resistant bacterial organism in palliative and geriatric care, contradictions between hygiene principles and patients’ and family caregivers’ needs and divergence from standards, frame conditions, and reflections on standardization of multidrug-resistant bacterial organism end-of-life care procedures. Results show that institutional stakeholders face a dilemma between their responsibility in protecting third persons and ensuring patients’ quality of life. Until further empirical evidence establishes a clear multidrug-resistant bacterial organism management approach in end-of-life care, stakeholders suggest a case-based approach. Conclusion The institutional stakeholders’ perspectives and their suggestion of a case-based approach advance the development

Understanding institutional stakeholders' perspectives on multidrug-resistant bacterial organism at the end of life: a qualitative study.

Science.gov (United States)

Heckel, Maria; Herbst, Franziska A; Adelhardt, Thomas; Tiedtke, Johanna M; Sturm, Alexander; Stiel, Stephanie; Ostgathe, Christoph

2017-01-01

Information lacks about institutional stakeholders' perspectives on management approaches of multidrug-resistant bacterial organism in end-of-life situations. The term "institutional stakeholder" includes persons in leading positions with responsibility in hospitals' multidrug-resistant bacterial organism management. They have great influence on how strategies on multidrug-resistant bacterial organism management approaches in institutions of the public health system are designed. This study targeted institutional stakeholders' individual perspectives on multidrug-resistant bacterial organism colonization or infection and isolation measures at the end of life. Between March and December 2014, institutional stakeholders of two study centers, a German palliative care unit and a geriatric ward, were queried in semistructured interviews. Interviews were audiotaped, transcribed verbatim, and analyzed qualitatively with the aid of the software MAXQDA for qualitative data analysis using principles of Grounded Theory. In addition, two external stakeholders were interviewed to enrich data. Key issues addressed by institutional stakeholders (N=18) were the relevance of multidrug-resistant bacterial organism in palliative and geriatric care, contradictions between hygiene principles and patients' and family caregivers' needs and divergence from standards, frame conditions, and reflections on standardization of multidrug-resistant bacterial organism end-of-life care procedures. Results show that institutional stakeholders face a dilemma between their responsibility in protecting third persons and ensuring patients' quality of life. Until further empirical evidence establishes a clear multidrug-resistant bacterial organism management approach in end-of-life care, stakeholders suggest a case-based approach. The institutional stakeholders' perspectives and their suggestion of a case-based approach advance the development process of a patient-, family-, staff-, and institutional

Crystal Structure of a Plant Multidrug and Toxic Compound Extrusion Family Protein.

Science.gov (United States)

Tanaka, Yoshiki; Iwaki, Shigehiro; Tsukazaki, Tomoya

2017-09-05

The multidrug and toxic compound extrusion (MATE) family of proteins consists of transporters responsible for multidrug resistance in prokaryotes. In plants, a number of MATE proteins were identified by recent genomic and functional studies, which imply that the proteins have substrate-specific transport functions instead of multidrug extrusion. The three-dimensional structure of eukaryotic MATE proteins, including those of plants, has not been reported, preventing a better understanding of the molecular mechanism of these proteins. Here, we describe the crystal structure of a MATE protein from the plant Camelina sativa at 2.9 Å resolution. Two sets of six transmembrane α helices, assembled pseudo-symmetrically, possess a negatively charged internal pocket with an outward-facing shape. The crystal structure provides insight into the diversity of plant MATE proteins and their substrate recognition and transport through the membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multi-drug resistant Ewingella Americana

International Nuclear Information System (INIS)

Bukhari, Syed Z.; Ashshi, Ahmad M.; Hussain, Waleed M.; Fatani, Mohammad I.

2008-01-01

We report a case of pneumonia due to multi-drug resistant Ewingella Americana in a young patient admitted in the Intensive Care Unit of Hera General Hospital, Makkah, Saudi Arabia with severe head injury in a road traffic accident. He was an Indonesian pilgrim who had traveled to the Kingdom of Saudi Arabia to perform Hajj in December 2007. Ewingella Americana was identified to be the pathogen of pneumonia with clinical signs and symptoms along with positive radiological findings. (author)

Influence of prognostic groupings and treatment results in the management of unresectable hepatoma: experience with cis-platinum-based chemoradiotherapy in 76 patients

International Nuclear Information System (INIS)

Abrams, Ross A.; Cardinale, Robert M.; Enger, Cheryl; Haulk, Thomas L.; Hurwitz, Herbert; Osterman, Floyd; Sitzmann, James V.

1997-01-01

Purpose: Internationally, hepatoma is a common cause of cancer death. Although the only curative therapy is surgical, most tumors are unresectable and cause death. The value of nonsurgical, antineoplastic therapy for such tumors is controversial. This study was undertaken to extend and confirm promising, but preliminary, treatment observations in the unresectable context. Methods and Materials: From 1988 to 1993, 76 patients with unresectable, biopsy proven, hepatoma underwent uniform pretreatment assessment followed by induction therapy with external beam radiotherapy (21 Gy/7 fractions/10 days) and intravenous Cisplatinum, 50 mg/m 2 . One month later patients began monthly intrahepatic artery Cisplatinum, 50 mg/m 2 . Clinical course and treatment outcomes were correlated with previously published prognostic factors and groupings (Nomura et al., Okuda et al., Stillwagon, et al.). Results: The toxicity of this therapy was modest and nonlimiting. Twenty-four patients (32%) progressed during induction and prior to receiving two cycles of intrahepatic artery Cisplatinum without evidence of benefit. Patients showing this early progression were more likely to be Stillwagon unfavorable than favorable (p = 0.013), Okuda Stage II than Stage I (p = 0.024), and slightly but not statistically more likely to be alpha-fetoprotein positive than alpha-fetoprotein negative (p = 0.098). The overall objective response rate was 43% (38% among AFP positive and 62% among AFP negative patients) (p = 0.15). Although 21 patients had evidence of extra hepatic metastases, survival for these patients did not differ from patients without metastases (p = 0.09) and patients with extra hepatic metastases were just as likely to show intrahepatic response (p = 0.84). Conclusion: The chemoradiotherapy program utilized produced objective response and minimal toxicity. One-third of patients progressed rapidly in spite of treatment. Among the remaining patients, response occurred frequently. This

Risk factors for multidrug resistant tuberculosis patients in Amhara ...

African Journals Online (AJOL)

Risk factors for multidrug resistant tuberculosis patients in Amhara National ... risk factors of MDR-TB patients in Amhara National Regional State, Ethiopia. ... strict adherence to directly observed therapy, appropriate management of TB ...

Multidrug-Resistant Tuberculosis and Culture Conversion with Bedaquiline

NARCIS (Netherlands)

Diacon, Andreas H.; Pym, Alexander; Grobusch, Martin P.; de Los Rios, Jorge M.; Gotuzzo, Eduardo; Vasilyeva, Irina; Leimane, Vaira; Andries, Koen; Bakare, Nyasha; de Marez, Tine; Haxaire-Theeuwes, Myriam; Lounis, Nacer; Meyvisch, Paul; de Paepe, Els; van Heeswijk, Rolf P. G.; Dannemann, Brian; Rolla, Valeria; Dalcomo, Margreth; Gripp, Karla; Escada, Rodrigo; Tavares, Isabel; Borga, Liamar; Thomas, Aleyamma; Rekha, Banu; Nair, Dina; Chandrasekar, Chockalingam; Parthasarathy, Ramavaran Thiruvengadaraj; Sekhar, Gomathi; Ganesh, Krishnamoorthy; Rajagopalan, Krishnakumar; Rajapandian, Gangadevi; Dorairajalu, Rajendran; Sharma, Surendra Kumar; Banavaliker, Jayant; Kadhiravan, Tamilarasu; Gulati, Vinay; Mahmud, Hanif; Gupta, Arvind; Bhatnagar, Anuj; Jain, Vipin; Hari, Smriti; Gupta, Yogesh Kumar; Vaid, Ashok; Cirule, Andra; Dravniece, Gunta; Skripconoka, Vija; Kuksa, Liga; Kreigere, Edite; Ramos, Carlos Rafael Seas; Amat y Leon, Ivan Arapovic

2014-01-01

BACKGROUND Bedaquiline (Sirturo, TMC207), a diarylquinoline that inhibits mycobacterial ATP synthase, has been associated with accelerated sputum-culture conversion in patients with multidrug-resistant tuberculosis, when added to a preferred background regimen for 8 weeks. METHODS In this phase 2b

The lactococcal secondary multidrug transporter LmrP confers resistance to lincosamides, macrolides, streptogramins and tetracyclines

NARCIS (Netherlands)

Putman, M; van Veen, HW; Degener, JE; Konings, WN

2001-01-01

The active efflux of toxic compounds by (multi)drug transporters is one of the mechanisms that bacteria have developed to resist cytotoxic drugs. The authors describe the role of the lactococcal secondary multidrug transporter LmrP in the resistance to a broad range of clinically important

Actions of exogenous histones and other proteins on [3H]-thymidine incorporation into DNA of Novikoff hepatoma cells

International Nuclear Information System (INIS)

Barra, R.; Beres, B.; Koch, M.R.; Lea, M.A.

1976-01-01

The effects of exogenous proteins on the incorporation of [ 3 H]-thymidine into DNA was studied in Novikoff hepatoma ascites cells incubated in Eagle's minimal essential medium. A liver cytosol fraction (8 mg protein/ml) caused approximately 80% inhibition of isotope incorporation. The inhibitory activity of cytosol fractions from Morris hepatomas 9618A 2 , 5123C and 20 were inversely related to their growth rate. Under conditions in which there appeared to be a density dependent inhibition of growth, a mean 10 to 20% stimulation of isotope incorporation was observed after addition of total calf thymus histones and individual fractions in the concentration range of 100 to 400μg/ml. In experiments with lower cell concentrations, a 60% or greater increase in [ 3 H]-thymidine incorporation could be obtained with total calf thymus histone and with Fl and arginine-rich histones from rat liver. At concentrations of 1 to 2 mg/ml, histones inhibited DNA synthesis. Bovine serum albumin had little effect on DNA synthesis. Polylysine caused an 80 to 90% inhibition at a concentration of 1 mg/ml, but stimulatory effects were detected under certain conditions at 10μg/ml. The results suggest critical dependence on the ratio of cell and exogenous protein concentration in the action of proteins on DNA synthesis. (author)

Tamoxifen reduces P-gp-mediated multidrug resistance via inhibiting the PI3K/Akt signaling pathway in ER-negative human gastric cancer cells.

Science.gov (United States)

Mao, Zonglei; Zhou, Jin; Luan, Junwei; Sheng, Weihua; Shen, Xiaochun; Dong, Xiaoqiang

2014-03-01

Multidrug resistance (MDR), mediated by overexpression of drug efflux transporters such as P-glycoprotein (P-gp), is a major problem limiting successful chemotherapy of gastric cancer. Tamoxifen (TAM), a triphenylethylene nonsteroidal antiestrogen agent, shows broad-spectrum antitumor properties. Emerging studies demonstrated that TAM could significantly reduce the MDR in a variety of human cancers. Here we investigated the effects and possible underlying mechanisms of action of TAM on the reversion of MDR in ER-negative human gastric cancer cells. Our results demonstrated that in MDR phenotype SGC7901/CDDP gastric cancer cells TAM dramatically lowered the IC50 of CDDP, 5-FU and ADM, increased the intracellular Rhodamine123 accumulation and induced G0/G1 phase arrest, while G2/M phase decreased accordingly. Furthermore, at the molecular level, TAM substantially decreased the expression of P-gp, p-Akt and the Akt-regulated downstream effectors such as p-GSK-3β, p-BAD, Bcl-XL and cyclinD1 proteins without affecting the expression of t-Akt, t-GSK-3β, t-BAD proteins in SGC7901/CDDP cells. Thus, our findings demonstrate that TAM reverses P-gp-mediated gastric cancer cell MDR via inhibiting the PI3K/Akt signaling pathway. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Multidrug resistance in pediatric urinary tract infections.

Science.gov (United States)

Gaspari, Romolo J; Dickson, Eric; Karlowsky, James; Doern, Gary

2006-01-01

Urinary tract infections (UTIs) represent a common infection in the pediatric population. Escherichia coli is the most common uropathogen in children, and antimicrobial resistance in this species complicates the treatment of pediatric UTIs. Despite the impact of resistance on empiric antibiotic choice, there is little data on multidrug resistance in pediatric patients. In this paper, we describe characteristics of multidrug-resistant E. coli in pediatric patients using a large national database of uropathogens antimicrobial sensitivities. Antimicrobial susceptibility patterns to commonly prescribed antibiotics were performed on uropathogens isolated from children presenting to participating hospitals between 1999 and 2001. Data were analyzed separately for four pediatric age groups. Single and multidrug resistance to ampicillin, amoxicillin-clavulanate, cefazolin, ciprofloxacin, nitrofurantoin, and trimethoprim-sulfamethoxazole (TMP-SMX) were performed on all specimens. There were a total of 11,341 E. coli urine cultures from 343 infants (0-4 weeks), 1,801 toddlers (5 weeks-24 months), 6,742 preteens (2-12 years), and 2,455 teens (13-17 years). E. coli resistance to ampicillin peaked in toddlers (52.8%) but was high in preteens (52.1%), infants (50.4%), and teens (40.6%). Resistance to two or more antibiotics varied across age groups, with toddlers (27%) leading preteens (23.1%), infants (21%), and teens (15.9%). Resistance to three or more antibiotics was low in all age groups (range 3.1-5.2%). The most common co-resistance in all age groups was ampicillin/TMP-SMZ. In conclusion, less than half of all pediatric UTIs are susceptible to all commonly used antibiotics. In some age groups, there is a significant percentage of co-resistance between the two most commonly used antibiotics (ampicillin and TMP-SMZ).

Immunoprecipitation assay of alpha-fetoprotein synthesis by cultured mouse hepatoma cells treated with estrogens and glucocorticoids.

Science.gov (United States)

Rosebrock, J A; Parker, C L; Kute, T E

1981-01-01

This investigation was to study the biosynthesis of 3H-labeled alpha-fetoprotein (AFP) by cultured mouse hepatoma (HEPA-2) cells. Both the function and regulation of this oncodevelopmental gene are unknown. However, evidence indicates that mechanisms controlling the expression of AFP involve aspects of both normal embryonic development and neoplastic transformation. the secretion of AFP was analyzed during different phases of the growth cycle to provide information on AFP production using standard culture conditions. The highest rate of secretion occurred during the stationary phase, followed by the late logarithmic and early logarithmic phases of growth, respectively. The production of AFP was then determined following the addition of glucocorticoids and estrogens in an attempt to understand hormonal factors that may be involved. Studies utilizing estradiol-17 beta indicated that the secretion of AFP did not appear to be sensitive to this steroid even though sucrose density gradient analysis of HEPA-2 cytosol, for estrogenic receptors, revealed competitive binding moieties on the 8S and 4S regions of the gradient. In contrast, the secretion of the total complement of proteins, including AFP, was significantly stimulated by the glucocorticoids, dexamethasone and corticosterone. Analysis of HEPA-2 cytosol for glucocorticoid receptors revealed binding components in the 7S and 3-4S regions of the gradient. The 3H-dexamethasone binding appeared to be stereospecific since nonlabeled dexamethasone, but not nonlabeled estradiol-17 beta, effectively displaced the bound radioactivity. The glucocorticoid-binding component in HEPA-2 therefore displayed characteristics reported for glucocorticoid receptors in normal liver and other hepatomas.

SirT1 confers hypoxia-induced radioresistance via the modulation of c-Myc stabilization on hepatoma cells

International Nuclear Information System (INIS)

Xie Yuexia; Zhang Jianghong; Shao Chunlin; Xu Yanwu

2012-01-01

Intratumoral hypoxia is an important contributory factor to tumor cell resistance to radiotherapy. SirT1, a nicotinamide adenine dinucleotide (NAD + )-dependent histone/protein deacetylase, has been linked to the decrease of radiation-induced DNA damage and seems to be critical for cancer therapy. The purpose of this study was to investigate the role of SirT1 in hypoxia-induced radiation response on hepatoma cells. It was found that the administration with resveratrol, a putative SirT1 activator, enhanced the resistance of HepG2 cells against radiation-induced DNA damage of MN formation under hypoxia condition; while nicotinamide, a well-known SirT1 inhibitor, sensitized this radiation damage. Nevertheless, pretreatment of cells with 10058-F4, a specific inhibitor of c-Myc, almost eliminated the nicotinamide-induced radiosensitive effect. Further studies revealed that resveratrol inhibited c-Myc protein accumulation via up-regulation of SirT1 expression and deacetylase activity, and this loss of c-Myc protein was abolished by inhibiting its degradation in the presence of MG132, a potent inhibitor of proteasome. In contrast, nicotinamide attenuated c-Myc protein degradation induced by radiation under hypoxia through inhibition of SirT1 deacetylase activity. Our findings suggest that SirT1 could serve as a novel potent target of radiation-induced DNA damage and thus as a potential strategy to advance the efficiency of radiation therapy in hepatoma entities. (author)

Overcoming cellular multidrug resistance using classical nanomedicine formulations

Czech Academy of Sciences Publication Activity Database

Kunjachan, S.; Blauz, A.; Möckel, D.; Theek, B.; Kiessling, F.; Etrych, Tomáš; Ulbrich, K.; van Bloois, L.; Storm, G.; Bartosz, G.; Rychlik, B.; Lammers, T.

2012-01-01

Roč. 45, č. 4 (2012), s. 421-428 ISSN 0928-0987 R&D Projects: GA AV ČR IAA400500806 Institutional research plan: CEZ:AV0Z40500505 Keywords : cancer * nanomedicine * multidrug resistance Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.987, year: 2012

Dual RNAseq shows the human mucosal immunity protein, MUC13, is a hallmark of Plasmodium exoerythrocytic infection

KAUST Repository

LaMonte, Gregory; Orjuela-Sanchez, Pamela; Wang, Lawrence; Li, Shangzhong; Swann, Justine; Cowell, Annie; Zou, Bing Yu; Abdel- Haleem Mohamed, Alyaa; Villa-Galarce, Zaira; Moreno, Marta; Tong-Rios, Carlos; Vinetz, Joseph; Lewis, Nathan; Winzeler, Elizabeth A

2017-01-01

The exoerythrocytic stage of Plasmodium malaria infection is a critical window for prophylactic intervention. Using a genome-wide dual RNA sequencing of flow-sorted infected and uninfected hepatoma cells we identify the human mucosal immunity gene, Mucin13 (MUC13), as strongly upregulated during Plasmodium exoerythrocytic hepatic-stage infection. We confirm that MUC13 expression is upregulated in hepatoma cell lines and primary hepatocytes. In immunofluorescence assays, host MUC13 protein expression distinguishes infected cells from adjacent uninfected cells and shows similar colocalization with parasite biomarkers such as UIS4 and HSP70. We further show that localization patterns are species independent, distinguishing both P. berghei and P. vivax infected cells, and that MUC13 can be used to identify compounds that inhibit parasite replication in hepatocytes across all Human-infecting Plasmodium species. This data presents a novel interface of host-parasite interactions in Plasmodium, in that a component of host mucosal immunity is reprogrammed to assist the progression of infection.

Dual RNAseq shows the human mucosal immunity protein, MUC13, is a hallmark of Plasmodium exoerythrocytic infection

KAUST Repository

LaMonte, Gregory

2017-10-03

The exoerythrocytic stage of Plasmodium malaria infection is a critical window for prophylactic intervention. Using a genome-wide dual RNA sequencing of flow-sorted infected and uninfected hepatoma cells we identify the human mucosal immunity gene, Mucin13 (MUC13), as strongly upregulated during Plasmodium exoerythrocytic hepatic-stage infection. We confirm that MUC13 expression is upregulated in hepatoma cell lines and primary hepatocytes. In immunofluorescence assays, host MUC13 protein expression distinguishes infected cells from adjacent uninfected cells and shows similar colocalization with parasite biomarkers such as UIS4 and HSP70. We further show that localization patterns are species independent, distinguishing both P. berghei and P. vivax infected cells, and that MUC13 can be used to identify compounds that inhibit parasite replication in hepatocytes across all Human-infecting Plasmodium species. This data presents a novel interface of host-parasite interactions in Plasmodium, in that a component of host mucosal immunity is reprogrammed to assist the progression of infection.

International spread of multidrug-resistant Salmonella Schwarzengrund in food products

DEFF Research Database (Denmark)

Aarestrup, Frank Møller; Hendriksen, Rene S.; Lockett, Jana

2007-01-01

We compared 581 Salmonella enterica serotype Schwarzengrund isolates from persons, food, and food animals in Denmark, Thailand, and the United States by antimicrobial drug susceptibility and pulsed-field gel electrophoresis (PFGE) typing. Resistance, including resistance to nalidixic acid......, was frequent among isolates from persons and chickens in Thailand, persons in the United States, and food imported from Thailand to Denmark and the United States. A total of 183 PFGE patterns were observed, and 136 (23.4%) isolates had the 3 most common patterns. Seven of 14 isolates from persons in Denmark...... had patterns found in persons and chicken meat in Thailand; 22 of 390 human isolates from the United States had patterns found in Denmark and Thailand. This study suggests spread of multidrug-resistant S. Schwarzengrund from chickens to persons in Thailand, and from imported Thai food products...

Community-acquired multidrug-resistant Gram-negative bacterial infective endocarditis.

Science.gov (United States)

Naha, Sowjanya; Naha, Kushal; Acharya, Vasudev; Hande, H Manjunath; Vivek, G

2014-08-05

We describe two cases of bacterial endocarditis secondary to multidrug-resistant Gram-negative organisms. In both cases, the diagnosis was made in accordance with the modified Duke's criteria and confirmed by histopathological analysis. Furthermore, in both instances there were no identifiable sources of bacteraemia and no history of contact with hospital or other medical services prior to the onset of symptoms. The patients were managed in similar fashion with prolonged broad-spectrum antibiotic therapy and surgical intervention and made complete recoveries. These cases highlight Gram-negative organisms as potential agents for endocarditis, as well as expose the dissemination of such multidrug-resistant bacteria into the community. The application of an integrated medical and surgical approach and therapeutic dilemmas encountered in managing these cases are described. 2014 BMJ Publishing Group Ltd.

Multidrug-Resistant Tuberculosis, Somalia, 2010–2011

Science.gov (United States)

Sindani, Ireneaus; Fitzpatrick, Christopher; Falzon, Dennis; Suleiman, Bashir; Arube, Peter; Adam, Ismail; Baghdadi, Samiha; Bassili, Amal

2013-01-01

In a nationwide survey in 2011, multidrug-resistant tuberculosis (MDR TB) was found in 5.2% and 40.8% of patients with new and previously treated TB, respectively. These levels of drug resistance are among the highest ever documented in Africa and the Middle East. This finding presents a serious challenge for TB control in Somalia. PMID:23621911

Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

DEFF Research Database (Denmark)

Theilade, M D; Gram, G J; Jensen, P B

1999-01-01

Multidrug resistance (MDR) remains a major problem in the successful treatment of small cell lung cancer (SCLC). New treatment strategies are needed, such as gene therapy specifically targeting the MDR cells in the tumor. Retroviral LacZ gene-containing vectors that were either pseudotyped...... for the gibbon ape leukemia virus (GALV-1) receptor or had specificity for the amphotropic murine leukemia virus (MLV-A) receptor were used for transduction of five SCLC cell lines differing by a range of MDR mechanisms. Transduction efficiencies in these cell lines were compared by calculating the percentage...... of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

Risk factors associated with multidrug resistant tuberculosis among ...

African Journals Online (AJOL)

Background: Multidrug resistant tuberculosis (MDR-TB) remains is an important public health problem in developing world. We conducted this study to determine risk factors associated with MDR-TB and drug susceptibility pattern to second line drug among MDR TB patients in Tanzania. Methods: Unmatched case control ...

Photoexcited quantum dots for killing multidrug-resistant bacteria

Science.gov (United States)

Courtney, Colleen M.; Goodman, Samuel M.; McDaniel, Jessica A.; Madinger, Nancy E.; Chatterjee, Anushree; Nagpal, Prashant

2016-05-01

Multidrug-resistant bacterial infections are an ever-growing threat because of the shrinking arsenal of efficacious antibiotics. Metal nanoparticles can induce cell death, yet the toxicity effect is typically nonspecific. Here, we show that photoexcited quantum dots (QDs) can kill a wide range of multidrug-resistant bacterial clinical isolates, including methicillin-resistant Staphylococcus aureus, carbapenem-resistant Escherichia coli, and extended-spectrum β-lactamase-producing Klebsiella pneumoniae and Salmonella typhimurium. The killing effect is independent of material and controlled by the redox potentials of the photogenerated charge carriers, which selectively alter the cellular redox state. We also show that the QDs can be tailored to kill 92% of bacterial cells in a monoculture, and in a co-culture of E. coli and HEK 293T cells, while leaving the mammalian cells intact, or to increase bacterial proliferation. Photoexcited QDs could be used in the study of the effect of redox states on living systems, and lead to clinical phototherapy for the treatment of infections.

Effect of methylglyoxal on multidrug-resistant Pseudomonas aeruginosa

Directory of Open Access Journals (Sweden)

Katsuhiko eHayashi

2014-04-01

Full Text Available Honey has a complex chemistry, and its broad-spectrum antimicrobial activity varies with floral source, climate, and harvesting conditions. Methylglyoxal was identified as the dominant antibacterial component of manuka honey. Although it has been known that methylglyoxal has antibacterial activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, there is not much information describing its activity against gram-negative bacteria. In this study, we report the effect of methylglyoxal against multidrug-resistant Pseudomonas aeruginosa (MDRP using 53 clinically isolated strains. We also assessed the effect of deleting the five multidrug efflux systems in P. aeruginosa, as well as the efflux systems in Escherichia coli and Salmonella enterica serovar Typhimurium, on MICs of methylglyoxal. Our results indicate that methylglyoxal inhibits the growth of MDRP at concentrations of 128–512 µg/ml (1.7–7.1 mM and is not recognized by drug efflux systems.

Glycyrrhiza glabra HPLC fractions: identification of Aldehydo Isoophiopogonone and Liquirtigenin having activity against multidrug resistant bacteria.

Science.gov (United States)

Rahman, Hazir; Khan, Ilyas; Hussain, Anwar; Shahat, Abdelaaty Abdelaziz; Tawab, Abdul; Qasim, Muhammad; Adnan, Muhammad; Al-Said, Mansour S; Ullah, Riaz; Khan, Shahid Niaz

2018-05-02

Medicinal plants have been founded as traditional herbal medicine worldwide. Most of the plant's therapeutic properties are due to the presence of secondary metabolites such as alkaloids, glycosides, tannins and volatile oil. The present investigation analyzed the High-Pressure Liquid Chromatography (HPLC) fractions of Glycyrrhiza glabra (Aqueous, Chloroform, Ethanol and Hexane) against multidrug resistant human bacterial pathogens (Escherichia coli, Acinetobacter baumannii, Staphylococcus aureus and Pseudomonas aeruginosa). All the fractions showed antibacterial activity, were subjected to LC MS/MS analysis for identification of bioactive compounds. Among total HPLC fractions of G. glabra (n = 20), three HPLC fractions showed potential activity against multidrug resistant (MDR) bacterial isolates. Fraction 1 (F1) of aqueous extracts, showed activity against A. baumannii (15 ± 0.5 mm). F4 from hexane extract of G. glabra showed activity against S. aureus (10 ± 0.2 mm). However, F2 from ethanol extract exhibited activity against S. aureus (10 ± 0.3 mm). These active fractions were further processed by LC MS/MS analysis for the identification of compounds. Ellagic acid was identified in the F1 of aqueous extract while 6-aldehydo-isoophiopogonone was present in F4 of hexane extract. Similarly, Liquirtigenin was identified in F2 of ethanol. Glycyrrhiza glabra extracts HPLC fractions showed anti-MDR activity. Three bioactive compounds were identified in the study. 6-aldehydo-isoophiopogonone and Liquirtigenin were for the first time reported in G. glabra. Further characterization of the identified compounds will be helpful for possible therapeutic uses against infectious diseases caused by multidrug resistant bacteria.

Mitochondrial DNA maintenance is regulated in human hepatoma cells by glycogen synthase kinase 3β and p53 in response to tumor necrosis factor α.

Science.gov (United States)

Vadrot, Nathalie; Ghanem, Sarita; Braut, Françoise; Gavrilescu, Laura; Pilard, Nathalie; Mansouri, Abdellah; Moreau, Richard; Reyl-Desmars, Florence

2012-01-01

During chronic liver inflammation, up-regulated Tumor Necrosis Factor alpha (TNF-α) targets hepatocytes and induces abnormal reactive oxygen species (ROS) production responsible for mitochondrial DNA (mtDNA) alterations. The serine/threonine Glycogen Synthase Kinase 3 beta (GSK3β) plays a pivotal role during inflammation but its involvement in the maintenance of mtDNA remains unknown. The aim of this study was to investigate its involvement in TNF-α induced mtDNA depletion and its interrelationship with p53 a protein known to maintain mtDNA copy numbers. Using quantitative polymerase chain reaction (qPCR) we found that at 30 min in human hepatoma HepG2 cells TNF-α induced 0.55±0.10 mtDNA lesions per 10 Kb and a 52.4±2.8% decrease in mtDNA content dependent on TNF-R1 receptor and ROS production. Both lesions and depletion returned to baseline from 1 to 6 h after TNF-α exposure. Luminol-amplified chemiluminescence (LAC) was used to measure the rapid (10 min) and transient TNF-α induced increase in ROS production (168±15%). A transient 8-oxo-dG level of 1.4±0.3 ng/mg DNA and repair of abasic sites were also measured by ELISA assays. Translocation of p53 to mitochondria was observed by Western Blot and co-immunoprecipitations showed that TNF-α induced p53 binding to GSK3β and mitochondrial transcription factor A (TFAM). In addition, mitochondrial D-loop immunoprecipitation (mtDIP) revealed that TNF-α induced p53 binding to the regulatory D-loop region of mtDNA. The knockdown of p53 by siRNAs, inhibition by the phosphoSer(15)p53 antibody or transfection of human mutant active GSK3βS9A pcDNA3 plasmid inhibited recovery of mtDNA content while blockade of GSK3β activity by SB216763 inhibitor or knockdown by siRNAs suppressed mtDNA depletion. This study is the first to report the involvement of GSK3β in TNF-α induced mtDNA depletion. We suggest that p53 binding to GSK3β, TFAM and D-loop could induce recovery of mtDNA content through mtDNA repair.

Mitochondrial DNA maintenance is regulated in human hepatoma cells by glycogen synthase kinase 3β and p53 in response to tumor necrosis factor α.

Directory of Open Access Journals (Sweden)

Nathalie Vadrot

Full Text Available During chronic liver inflammation, up-regulated Tumor Necrosis Factor alpha (TNF-α targets hepatocytes and induces abnormal reactive oxygen species (ROS production responsible for mitochondrial DNA (mtDNA alterations. The serine/threonine Glycogen Synthase Kinase 3 beta (GSK3β plays a pivotal role during inflammation but its involvement in the maintenance of mtDNA remains unknown. The aim of this study was to investigate its involvement in TNF-α induced mtDNA depletion and its interrelationship with p53 a protein known to maintain mtDNA copy numbers. Using quantitative polymerase chain reaction (qPCR we found that at 30 min in human hepatoma HepG2 cells TNF-α induced 0.55±0.10 mtDNA lesions per 10 Kb and a 52.4±2.8% decrease in mtDNA content dependent on TNF-R1 receptor and ROS production. Both lesions and depletion returned to baseline from 1 to 6 h after TNF-α exposure. Luminol-amplified chemiluminescence (LAC was used to measure the rapid (10 min and transient TNF-α induced increase in ROS production (168±15%. A transient 8-oxo-dG level of 1.4±0.3 ng/mg DNA and repair of abasic sites were also measured by ELISA assays. Translocation of p53 to mitochondria was observed by Western Blot and co-immunoprecipitations showed that TNF-α induced p53 binding to GSK3β and mitochondrial transcription factor A (TFAM. In addition, mitochondrial D-loop immunoprecipitation (mtDIP revealed that TNF-α induced p53 binding to the regulatory D-loop region of mtDNA. The knockdown of p53 by siRNAs, inhibition by the phosphoSer(15p53 antibody or transfection of human mutant active GSK3βS9A pcDNA3 plasmid inhibited recovery of mtDNA content while blockade of GSK3β activity by SB216763 inhibitor or knockdown by siRNAs suppressed mtDNA depletion. This study is the first to report the involvement of GSK3β in TNF-α induced mtDNA depletion. We suggest that p53 binding to GSK3β, TFAM and D-loop could induce recovery of mtDNA content through mtDNA repair.

plasmid mediated resistance in multidrug resistant bacteria isolated

African Journals Online (AJOL)

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PLASMID MEDIATED RESISTANCE IN MULTIDRUG RESISTANT BACTERIA. ISOLATED FROM CHILDREN WITH SUSPECTED SEPTICAEMIA IN ZARIA,. NIGERIA. AbdulAziz, Z. A.,1* Ehinmidu, J. O.,1 Adeshina, G. O.,1 Pala, Y. Y2., Yusuf, S. S2. and. Bugaje, M. A.3. 1Department of Pharmaceutics and Pharmaceutical ...

Multidrug-resistant hepatocellular carcinoma cells are enriched for ...

African Journals Online (AJOL)

Chemotherapy is a main treatment for cancer, while multidrug-resistance is the main reason for chemotherapy failure, and tumor relapse and metastasis. Cancer stem cells or cancer stem-like cells (CSCs) are a small subset of cancer cells, which may be inherently resistant to the cytotoxic effect of chemotherapy.

Prevalence and risk factors for carriage of multi-drug resistant Staphylococci in healthy cats and dogs

Science.gov (United States)

Regula, Gertraud; Petrini, Orlando; Zinsstag, Jakob; Schelling, Esther

2013-01-01

We investigated the distribution of commensal staphylococcal species and determined the prevalence of multi-drug resistance in healthy cats and dogs. Risk factors associated with the carriage of multi-drug resistant strains were explored. Isolates from 256 dogs and 277 cats were identified at the species level using matrix-assisted laser desorption ionisation-time of flight mass spectrometry. The diversity of coagulase-negative Staphylococci (CNS) was high, with 22 species in dogs and 24 in cats. Multi-drug resistance was frequent (17%) and not always associated with the presence of the mecA gene. A stay in a veterinary clinic in the last year was associated with an increased risk of colonisation by multi-drug resistant Staphylococci (OR = 2.4, 95% CI: 1.1~5.2, p value LRT = 0.04). When identifying efficient control strategies against antibiotic resistance, the presence of mechanisms other than methicillin resistance and the possible role of CNS in the spread of resistance determinants should be considered. PMID:23820161

Exploring the iron metabolism in multidrug resistant tuberculosis ...

African Journals Online (AJOL)

The iron metabolism plays a key role in the progression of active Tuberculosis. Several studies have shown a link between iron metabolism disorders an active tuberculosis. The aim of this study was to explore the iron metabolism of 100 patients with multidrug-resistant tuberculosis (MDR-TB) treated with second generation ...

Exploring the iron metabolism in multidrug resistant tuberculosis ...

African Journals Online (AJOL)

The iron metabolism plays a key role in the progression of active Tuberculosis. Several studies have shown a link between iron metabolism disorders an active tuberculosis. The aim of this study was to explore the iron metabolism of 100 patients with multidrug-resistant tuberculosis. (MDR-TB) treated with second ...

The chicken c-erbA alpha-product induces expression of thyroid hormone-responsive genes in 3,5,3'-triiodothyronine receptor-deficient rat hepatoma cells

DEFF Research Database (Denmark)

Muñoz, A; Höppner, W; Sap, J

1990-01-01

To determine the capacity of the chicken c-erbA (cTR-alpha) gene product in regulating expression of known thyroid hormone-responsive genes, both the cTR-alpha and the viral v-erbA genes were expressed in FAO cells, a rat hepatoma cell line defective for functional thyroid hormone receptors. Upon...

Multi-drug resistant tuberculosis in Tanzania: Initial description of ...

African Journals Online (AJOL)

Background: Drug resistant Tuberculosis is well documented worldwide and is associated with increasing morbidity and mortality complicating Tuberculosis control with increasing costs of managing the disease. Broad. Objective: To describe clinical and laboratory characteristics of multi-drug resistant Tuberculosis ...

The multidrug ABC transporter BmrC/BmrD of Bacillus subtilis is regulated via a ribosome-mediated transcriptional attenuation mechanism

OpenAIRE

Reilman, E.; Mars, R. A. T.; van Dijl, J. M.; Denham, Emma

2014-01-01

Expression of particular drug transporters in response to antibiotic pressure is a critical element in the development of bacterial multidrug resistance, and represents a serious concern for human health. To obtain a better understanding of underlying regulatory mechanisms, we have dissected the transcriptional activation of the ATP-binding cassette (ABC) transporter BmrC/BmrD of the Gram-positive model bacterium Bacillus subtilis. By using promoter-GFP fusions and live cell array technology,...

Characterization and antimicrobial susceptibility of one antibiotic-sensitive and one multidrug-resistant Corynebacterium kroppenstedtii strain isolated from patients with granulomatous mastitis

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I. Fernández-Natal

2016-11-01

Full Text Available Human infections associated with Corynebacterium kroppenstedtii are rarely reported, and this organism is usually described as antibiotic sensitive. Almost all published cases of C. kroppenstedtii infections have been associated with breast pathology in women and have been described in New Zealand, France, Canada, India and Japan. Here we describe the microbiologic characteristics of two strains isolated from two women diagnosed of granulomatous mastitis in Spain. One C. kroppenstedtii isolate was antibiotic sensitive while the other was multidrug resistant. Biochemical identification was possible using a wide battery of methods including API Coryne V2.0, API Strep, API NH, API NE, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene amplification and sequencing. Antimicrobial susceptibility to 28 antibiotics as determined by Etest showed one isolate being sensitive to benzylpenicillin, ciprofloxacin, moxifloxacin, gentamicin, vancomycin, clindamycin, tetracycline, linezolid and rifampin. The second isolate showed resistance to ciprofloxacin, moxifloxacin, clindamycin, tetracycline and rifampin. The multidrug-resistant isolate contained the erm(X, tet(W, cmx, aphA1-IAB, strAB and sul1 resistance genes known from the R plasmid pJA144188 of Corynebacterium resistens. These genes were absent in the genome of the antibiotic-sensitive isolate. This report confirms the tropism of this microorganism for women's breasts and presents the first description of a multidrug-resistant C. kroppenstedtii strain.

Intraventricular ciprofloxacin usage in treatment of multidrug-resistant central nervous system infections: report of four cases

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Ayse Karaaslan

2014-12-01

Full Text Available In recent years, multidrug-resistant microorganisms appear as important nosocomial pathogens which treatment is quite difficult. As sufficient drug levels could not be achieved in cerebrospinal fluid during intravenous antibiotic therapy for central nervous system infections and due to multidrug-resistance treatment alternatives are limited. In this study, four cases of central nervous system infections due to multidrug-resistant microorganisms who were successfully treated with removal of the devices and intraventricular ciprofloxacin are presented. In conclusion, intraventricular ciprofloxacin can be used for treatment of central nervous system infections if the causative microorganism is sensitive to the drug and no other alternative therapy is available.

Mechanisms of MRP over-expression in four human lung-cancer cell lines and analysis of the MRP amplicon

NARCIS (Netherlands)

Eijdems, E. W.; de Haas, M.; Coco-Martin, J. M.; Ottenheim, C. P.; Zaman, G. J.; Dauwerse, H. G.; Breuning, M. H.; Twentyman, P. R.; Borst, P.; Baas, F.

1995-01-01

Some multidrug resistant cell lines over-express the gene encoding the multidrug-resistance-associated protein (MRP). In all cell lines reported thus far, over-expression is associated with gene amplification. We have studied the predominant mechanisms of MRP over-expression in 4 human lung-cancer

MECHANISMS OF MRP OVER-EXPRESSION IN 4 HUMAN LUNG-CANCER CELL-LINES AND ANALYSIS OF THE MRP AMPLICON

NARCIS (Netherlands)

EIJDEMS, EWHM; DEHAAS, M; COCOMARTIN, JM; OTTENHEIM, CPE; ZAMAN, GJR; DAUWERSE, HG; BREUNING, MH; TWENTYMAN, PR; BORST, P; BAAS, F

1995-01-01

Some multidrug resistant cell lines over-express the gene encoding the multidrug-resistance-associated protein (MRP). In all cell lines reported thus far, over-expression is associated with gene amplification. We have studied the predominant mechanisms of MRP over-expression in 4 human lung-cancer

Decreasing prevalence of multi-drugs resistant Mycobacterium tuberculosis in Nashik City, India

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Arun P. More

2013-03-01

Full Text Available Objective: In India, increasing prevalence of multi-drug resistant tuberculosis (MDR has aggravated the control oftuberculosis problem. In many urban and semi-urban regions of India, no surveillance data of multidrug resistance inMycobacterium tuberculosisis available.Methods: A surveillance study on multidrug resistance was carried out in semi-urban and rural regions in and aroundNashik City of Maharashtra, India. The surveillance study was conducted in this region found that the prevalence ofcombined resistance to first and second-line anti-tuberculosis drugs is remarkably high. The isolates of M. tuberculosiswas identified and subjected to drug susceptibility testing. The patterns of drug susceptibility of isolates of M. tuberculosisduring the periods 2000 and 2004 were compared with drug susceptibility patterns of the organisms during theperiod 2008 to 2011.Results: The 260 isolates identified as M. tuberculosis show mean drug resistance prevalence of 45.6% for more than anytwo drugs and the MDR rate as 37% in the years 2000 to 2004 whereas 305 isolates of the organism show mean drugresistance prevalence of 30.2% and the MDR rate as 25% in the years 2008 to 2011.Conclusion: The researcher found that, though the prevalence of multidrug resistance to the drugs tested is remarkablyhigh, it has come down noticeably during the past seven years due to efforts of State Government and strict implementationof treatment guidelines of WHO by the physicians. J Microbiol Infect Dis 2013; 3(1: 12-17Key words: MDR-TB, XDR-TB, DOTS, drug-resistance prevalence rate.

In vitro antibacterial activity of rifampicin in combination with imipenem, meropenem and doripenem against multidrug-resistant clinical isolates of Pseudomonas aeruginosa.

Science.gov (United States)

Hu, Yi-Fan; Liu, Chang-Pan; Wang, Nai-Yu; Shih, Shou-Chuan

2016-08-24

Multidrug-resistant Pseudomonas aeruginosa has emerged as one of the most important healthcare-associated pathogens. Colistin is regarded as the last-resort antibiotic for multidrug-resistant Gram-negative bacteria, but is associated with high rates of acute kidney injury. The aim of this in vitro study is to search for an alternative treatment to colistin for multidrug-resistant P. aeruginosa infections. Multidrug and carbapenem-resistant P. aeruginosa isolates were collected between January 2009 and December 2012 at MacKay Memorial Hospital. Minimal inhibitory concentrations (MICs) were determined for various antibiotic combinations. Carbapenemase-producing genes including bla VIM, other β-lactamase genes and porin mutations were screened by PCR and sequencing. The efficacy of carbapenems (imipenem, meropenem, doripenem) with or without rifampicin was correlated with the type of porin mutation (frameshift mutation, premature stop codon mutation) in multidrug-resistant P. aeruginosa isolates without carbapenemase-producing genes. Of the 71 multidrug-resistant clinical P. aeruginosa isolates, only six harboured the bla VIM gene. Imipenem, meropenem and doripenem were significantly more effective (reduced fold-change of MICs) when combined with rifampicin in bla VIM-negative isolates, especially in isolates with porin frameshift mutation. Imipenem + rifampicin combination has a low MIC against multidrug-resistant P. aeruginosa, especially in isolates with porin frameshift mutation. The imipenem + rifampicin combination may provide an alternative treatment to colistin for multidrug -resistant P. aeruginosa infections, especially for patients with renal insufficiency.

Clarithromycin increases linezolid exposure in multidrug-resistant tuberculosis patients

NARCIS (Netherlands)

Bolhuis, Mathieu S.; van Altena, Richard; van Soolingen, Dick; de Lange, Wiel C. M.; Uges, Donald R. A.; van der Werf, Tjip S.; Kosterink, Jos G. W.; Alffenaar, Jan-Willem C.

2013-01-01

The use of linezolid for the treatment of multidrug-resistant tuberculosis is limited by dose-and time-dependent toxicity. Recently, we reported a case of pharmacokinetic drug drug interaction between linezolid and clarithromycin that resulted in increased linezolid exposure. The aim of this

Reversal of multidrug resistance by surfactants.

Science.gov (United States)

Woodcock, D. M.; Linsenmeyer, M. E.; Chojnowski, G.; Kriegler, A. B.; Nink, V.; Webster, L. K.; Sawyer, W. H.

1992-01-01

Cremophor EL, a pharmacologically inactive solubilising agent, has been shown to reverse multidrug resistance (MDR). Using flow cytometric evaluation of equilibrium intracellular levels of daunorubicin (DNR), we found that eight other surface active agents will also reverse MDR. All the active detergents contain polyethoxylated moieties but have no similarities in their hydrophobic components. The properties of three polyethoxylated surfactants that showed the lowest toxicities, Cremophor, Tween 80 and Solutol HS15, were examined in more detail. The concentrations of Tween 80 and Solutol required to reverse DNR exclusion were 10-fold lower than for Cremophor. However while concentrations greater than or equal to 1:10(2) of the former two surfactants resulted in breakdown of cells, even 1:10 of Cremophor did not lyse cells. Studies of the effects of Cremophor on the uptake and efflux of DNR in normal and MDR cell types showed that Cremophor increases intracellular DNR primarily by locking the rapid efflux from the cells. This blockage of drug efflux may be mediated by a substantial alteration in the fluidity of cell membranes induced by Cremophor, as shown by decreased fluorescence anisotropy of a membrane probe. Consistent with these data, coinjection of adriamycin plus Cremophor into mice carrying a multidrug resistant P388 transplantable tumour significantly increased the survival time of the mice compared with adriamycin treatment alone. PMID:1637678

RND multidrug efflux pumps: what are they good for?

Science.gov (United States)

Alvarez-Ortega, Carolina; Olivares, Jorge; Martínez, José L.

2013-01-01

Multidrug efflux pumps are chromosomally encoded genetic elements capable of mediating resistance to toxic compounds in several life forms. In bacteria, these elements are involved in intrinsic and acquired resistance to antibiotics. Unlike other well-known horizontally acquired antibiotic resistance determinants, genes encoding for multidrug efflux pumps belong to the core of bacterial genomes and thus have evolved over millions of years. The selective pressure stemming from the use of antibiotics to treat bacterial infections is relatively recent in evolutionary terms. Therefore, it is unlikely that these elements have evolved in response to antibiotics. In the last years, several studies have identified numerous functions for efflux pumps that go beyond antibiotic extrusion. In this review we present some examples of these functions that range from bacterial interactions with plant or animal hosts, to the detoxification of metabolic intermediates or the maintenance of cellular homeostasis. PMID:23386844

Epidemiologic analysis: Prophylaxis and multidrug-resistance in surgery.

Science.gov (United States)

Solís-Téllez, H; Mondragón-Pinzón, E E; Ramírez-Marino, M; Espinoza-López, F R; Domínguez-Sosa, F; Rubio-Suarez, J F; Romero-Morelos, R D

Surgical site infection is defined as an infection related to the surgical procedure in the area of manipulation occurring within the first 30 postoperative days. The diagnostic criteria include: purulent drainage, isolation of microorganisms, and signs of infection. To describe the epidemiologic characteristics and differences among the types of prophylactic regimens associated with hospital-acquired infections at the general surgery service of a tertiary care hospital. The electronic case records of patients that underwent general surgery at a tertiary care hospital within the time frame of January 1, 2013 and December 31, 2014 were reviewed. A convenience sample of 728 patients was established and divided into the following groups: Group 1: n=728 for the epidemiologic study; Group 2: n=638 for the evaluation of antimicrobial prophylaxis; and Group 3: n=50 for the evaluation of multidrug-resistant bacterial strains in the intensive care unit. The statistical analysis was carried out with the SPSS 19 program, using the Mann-Whitney U test and the chi-square test. A total of 728 procedures were performed (65.9% were elective surgeries). Three hundred twelve of the patients were males and 416 were females. Only 3.98% of the patients complied with the recommended antimicrobial prophylaxis, and multidrug-resistant bacterial strains were found in the intensive care unit. A single prophylactic dose is effective, but adherence to this recommendation was not adequate. The prophylactic guidelines are not strictly adhered to in our environment. There was a significant association between the development of nosocomial infections from multidrug-resistant germs and admission to the intensive care unit. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

[Antimicrobial therapy in severe infections with multidrug-resistant Gram-negative bacterias].

Science.gov (United States)

Duszyńska, Wiesława

2010-01-01

Multidrug-resistant Gram-negative bacteria pose a serious and rapidly emerging threat to patients in healthcare settings, and are especially prevalent and problematic in intensive therapy units. Recently, the emergence of pandrug-resistance in Gram-negative bacteria poses additional concerns. This review examines the clinical impact and epidemiology of multidrug-resistant Gram-negative bacteria as a cause of increased morbidity and mortality among ITU patients. Beta-lactamases, cephalosporinases and carbapenemases play the most important role in resistance to antibiotics. Despite the tendency to increased resistance, carbapenems administered by continuous infusion remain the most effective drugs in severe sepsis. Drug concentration monitoring, albeit rarely used in practice, is necessary to ensure an effective therapeutic effect.

Yeast endoribonuclease stimulated by Novikoff Hepatoma small nuclear RNAS U1 and U2

International Nuclear Information System (INIS)

Stevens, A.

1982-01-01

Using [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) from yeast as a substrate, an endoribonuclease has been detected in enzyme fractions derived from a high salt wash of ribonucleoprotein particles of Saccharomyces cerevisiae. The [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) seems to be a preferred substrate since other polyribonucleotides are hydrolyzed more slowly, if at all. The enzyme is inhibited by ethidium bromide, but fully double-stranded polyribonucleotides are not hydrolyzed. The hydrolysis of [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) is stimulated about 2.5-fold by the addition of small nuclear RNAs U1 and U2 of Novikoff hepatoma cells. Results show that the stimulation involves an interaction of the labeled RNA with the small nuclear RNA

Bedaquiline in the multidrug-resistant tuberculosis treatment: Belarus experience

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Alena Skrahina

2016-01-01

Conclusion: Our interim results on safety and effectiveness of bedaquiline-containing regimens in multidrug and extensively drug-resistant tuberculosis (M/XDR-TB patients are encouraging. They will add value to understanding role and place of this new anti-TB drug in M/XDR-TB treatment.

Health system factors influencing management of multidrug-resistant tuberculosis in four European Union countries - learning from country experiences

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Gerard de Vries

2017-04-01

Full Text Available Abstract Background In the European Union and European Economic Area only 38% of multidrug-resistant tuberculosis patients notified in 2011 completed treatment successfully at 24 months’ evaluation. Socio-economic factors and patient factors such as demographic characteristics, behaviour and attitudes are associated with treatment outcomes. Characteristics of healthcare systems also affect health outcomes. This study was conducted to identify and better understand the contribution of health system components to successful treatment of multidrug-resistant tuberculosis. Methods We selected four European Union countries to provide for a broad range of geographical locations and levels of treatment success rates of the multidrug-resistant tuberculosis cohort in 2009. We conducted semi-structured interviews following a conceptual framework with representatives from policy and planning authorities, healthcare providers and civil society organisations. Responses were organised according to the six building blocks of the World Health Organization health systems framework. Results In the four included countries, Austria, Bulgaria, Spain, and the United Kingdom, the following healthcare system factors were perceived as key to achieving good treatment results for patients with multidrug-resistant tuberculosis: timely diagnosis of drug-resistant tuberculosis; financial systems that ensure access to a full course of treatment and support for multidrug-resistant tuberculosis patients; patient-centred approaches with strong intersectoral collaboration that address patients’ emotional and social needs; motivated and dedicated healthcare workers with sufficient mandate and means to support patients; and cross-border management of multidrug-resistant tuberculosis to secure continuum of care between countries. Conclusion We suggest that the following actions may improve the success of treatment for multidrug-resistant tuberculosis patients: deployment of

Genotoxic activity and induction of biotransformation enzymes in two human cell lines after treatment by Erika fuel extract.

Science.gov (United States)

Amat-Bronnert, Agnès; Castegnaro, Marcel; Pfohl-Leszkowicz, Annie

2007-01-01

On 12 December 1999, the tanker Erika broke in two parts at about 60km from the Brittany French coasts (Point of Penmarc'h, Sud Finistère, France). About 10,000tonnes of heavy oil fuel were released in the sea. DNA adduct have been detected in fish liver and mussels digestive gland exposed to the Erika oil spill. In order to investigate the mechanism by which Erika fuel extract exhibits genotoxic effects the induction of DNA adducts by an Erika fuel extract have been analysed on two cell lines, human epithelial bronchial cells (WI) and human hepatoma cells. DNA adducts, reflected by a diagonal radioactive zone and individual adducts are detected only in hepatoma cells indicating biotransformation via CYP 1A2 and CYP 1B1. In addition, Erika fuel extract induces some metabolizing enzymes such CYP 1A2, COX2 and 5-LOX, the two later are involved in cancer processes. Formation of leucotrienes B4 (LTB(4)), a mediator playing a role in inflammation, is induced in epithelial bronchial cells. Since inhalation is one of the ways of contamination for human, the above results are important for human health and prevention. Copyright © 2006 Elsevier B.V. All rights reserved.

High incidence of multidrug-resistant strains of methicill inresistant ...

African Journals Online (AJOL)

Infections of methicillin-resistant Staphylococcus aureus (MRSA) are becoming an increasingly concerning clinical problem. The aim of this study was to assess the development of multidrug resistant strains of MRSA from clinical samples andpossibilities for reducing resistance. This study included a total of seventy-five (75) ...

Antimicrobial activity of peptidomimetics against multidrug-resistant Escherichia coli

DEFF Research Database (Denmark)

Jahnsen, Rasmus D; Frimodt-Møller, Niels; Franzyk, Henrik

2012-01-01

Novel remedies in the battle against multidrug-resistant bacterial strains are urgently needed, and one obvious approach involves antimicrobial peptides and mimics hereof. The impact of a- and ß-peptoid as well as ß(3)-amino acid modifications on the activity profile against ß-lactamase-producing...

Beyond multidrug-resistant tuberculosis in Europe: a TBNET study

NARCIS (Netherlands)

Günther, G.; van Leth, F.; Altet, N.; Dedicoat, M.; Duarte, R.; Gualano, G.; Kunst, H.; Muylle, I.; Spinu, V.; Tiberi, S.; Viiklepp, P.; Lange, C.; Alexandru, S.; Cernenco, I.; Ciobanu, A.; Donica, A.; Cayla, J.; Fina, L.; Galvao, M. L. de Souza; Maldonado, J.; Avsar, K.; Bang, D.; Andersen, A. B.; Barbuta, R.; Dubceac, V.; Bothamley, G.; Crudu, V.; Davilovits, M.; Atunes, A.; de Lange, W.; Leimane, V.; Rusmane, L.; de Lorenzo, S.; Cuppen, F.; de Guchtenaire, I.; Magis-Escurra, C.; McLaughlin, A.-M.; Meesters, R.; te Pas, M.; Prins, B.; Mütterlein, R.; Kotrbova, J.; Polcová, V.; Vasakova, M.; Pontali, E.; Rumetshofer, R.; Rowhani, M.; Skrahina, A.; Avchinko, V.; Katovich, D.

2015-01-01

The emergence of drug-resistant tuberculosis (TB) is a challenge to TB control in Europe. We evaluated second-line drug susceptibility testing in Mycobacterium tuberculosis isolates from patients with multidrug-resistant, pre-extensively drug-resistant (pre-XDR-TB) and XDR-TB at 23 TBNET sites in 16

Antibacterial activity of exogenous glutathione and its synergism on antibiotics sensitize carbapenem-associated multidrug resistant clinical isolates of Acinetobacter baumannii.

Science.gov (United States)

Alharbe, Roaa; Almansour, Ayidh; Kwon, Dong H

2017-10-01

A major clinical impact of A. baumannii is hospital-acquired infections including ventilator-associated pneumonia. The treatment of this pathogen is often difficult due to its innate and acquired resistance to almost all commercially available antibiotics. Infections with carbapenem-associated multidrug resistant A. baumannii is the most problematic. Glutathione is a tripeptide thiol-antioxidant and antibacterial activity of exogenous glutathione was reported in some bacteria. However, clinical relevance and molecular details of the antibacterial activity of glutathione are currently unclear. Seventy clinical isolates of A. baumannii including 63 carbapenem-associated multidrug resistant isolates and a type strain A. baumannii ATCC 19606 were used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Fractional inhibitory concentration (FIC) and time-killing activity with meropenem and/or glutathione were also determined in the carbapenem-associated multidrug resistant isolates. In addition, the roles of exogenous glutathione in multidrug efflux pumps and β-lactamase production were examined. Levels of MIC and MBC were ranged from 10 to 15mM of exogenous glutathione. All tested carbapenem-associated multidrug resistant isolates were sensitized by all tested antibiotics in combination with subinhibitory concentrations of glutathione. FIC levels of glutathione with carbapenem (meropenem) were allcarbapenem-associated multidrug resistant isolates were killed by subinhibitory concentrations of both glutathione and meropenem at>2log10 within 12h, suggesting glutathione synergistically interacts with meropenem. The roles of multidrug efflux pumps and β-lactamase production were excluded for the glutathione-mediated antibiotic susceptibility. Overall results demonstrate that the antibacterial activity of glutathione is clinically relevant and its synergism on antibiotics sensitizes clinical isolates of A. baumannii regardless

Active surveillance for asymptomatic colonisation by multidrug-resistant bacteria in patients transferred to a tertiary care hospital in the occupied Palestinian territory.

Science.gov (United States)

Taha, Adham Abu; Daoud, Ayman; Zaid, Sawsan; Sammour, Sajida; Belleh, Maram; Daifi, Refqa

2018-02-21

Active surveillance is important in infection control programmes, allowing the detection of patients colonised with multi-drug resistant organisms and preventing the spread of multi-drug resistant organisms. The aim of this study was to determine the rate of asymptomatic colonisation with multi-drug resistant organisms and the prevalence of each organism in patients transferred to An-Najah National University Hospital, Nablus, occupied Palestinian territory. Patients transferred from other hospitals between January and December, 2015, were screened at time of admission by taking nasal, groin, and axillary swabs. Swabs were cultured and assessed for the presence of multi-drug resistant organisms (extended spectrum β-lactamase producers, Pseudomonas aeroginosae, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococcus, and carbapenem-resistant enterobacteriaceae. Of the 822 screened patients, 265 (32%) had infections with multi-drug resistant organisms. 394 isolates of multi-drug resistant organisms were obtained: 131 (33%) isolates were extended spectrum β-lactamase producers, 119 (30%) isolates were P aeroginosae, 26 (9%) isolates were A baumannii, 94 (24%) isolates were methicillin-resistant S aureus, 13 (3%) isolates were vancomycin-resistant enterococci, and one (<1%) isolate was carbapenem-resistant enterobacteriaceae. We identified a high prevalence of asymptomatic colonisation with multidrug-resistant bacteria in transferred patients. These findings emphasise the need for a national strategy to combat the spread of multi-drug resistant organisms in the occupied Palestinian territory. An-Najah National University. Copyright © 2018 Elsevier Ltd. All rights reserved.

Icaritin inhibits the expression of alpha-fetoprotein in hepatitis B virus-infected hepatoma cell lines through post-transcriptional regulation.

Science.gov (United States)

Zhang, Chao; Li, Hui; Jiang, Wei; Zhang, Xiaowei; Li, Gang

2016-12-13

Although it has showed that icaritin can apparently suppress growth of HCC by reducing the level of AFP, the intrinsic mechanism remains unclear. In this study, we explored the possible mechanism of miRNAs on post-transcriptional regulation of AFP gene, as well as the effects of HBV infection and icaritin in hepatoma cells. The results showed that miR-620, miR-1236 and miR-1270 could bind target sites in the range of 9-18 nt and 131-151 nt downstream of the stop codon in the AFP mRNA 3'-UTR to suppress the expression of AFP. Mutation of these target sites could reverse the effects of these miRNAs. Icaritin (10 μM) might reduce the stability and translational activity of AFP mRNA by increasing the expression levels of these mentioned miRNAs. HBV infection resulted in apparent decreases of these miRNAs and, consequently, increased AFP expression. The results indicated that miR-620, miR-1236 and miR-1270 are critical factors in the post-transcriptional regulation of AFP. Icaritin can counteract the effect of HBV. These findings will contribute to full understanding of the regulatory mechanism of AFP expression in hepatoma cells. And also it revealed a synergistic mechanism of HBV infection and elevation of AFP in the pathogenesis of HCC, as well as the potential clinical significance of icaritin on the therapy of HCC induced by HBV.

In vitro uptakes of radiolabeled IVDU and IVFRU in herpes simplex virus type-1 thymidine kinase (HSV1-tk) gene transduced morris hepatoma cell line

Energy Technology Data Exchange (ETDEWEB)

Lee, Tae Sup; Choi, Tae Hyun; Ahn, Soon Hyuk; Woo, Kwang Sun; Jeong, Wee Sup; Kwon, Hee Chung; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Awh, Ok Doo [College of Health Sciences, Yonsei Univ., Wonju (Korea, Republic of)

2004-02-01

The herpes simplex virus type 1 thymidine kinase gene(HSV1-tk) is an attractive candidate as a reporter gene in noninvasive reporter gene monitoring system. The HSV1-tk gene was chosen as a reporter gene, because it has been extensively studied, and there are appropriate reporter probes, substrates of HSV1-tk gene product, to apply for HSV1-tk gene imaging. We used radiolabeled 5-iodovinyl-2'-deoxyuridine (IVDU) and 5-lodovinyl-2'-fluoro-2'-deoxyuridine (IVFRU) as reporter probes for HSV1-tk gene monitoring system. We prepared HSV1-tk gene transduced Morris hepatoma cell line using retroviral vector, MOLTEN containing HSV1-tk gene. And we confirmed the HSV1-tk gene expression by Northern blotting and Western blotting. We compared in vitro uptakes of radioiodinated IVDU and IVFRU to monitor HSV1-tk gene expression in Morris hepatoma cell line (MCA) and HSV1-tk gene tranduced MCA (MAC-tk) cells until 480 minutes. We also performed correlation analysis between percentage of HSV1-tk gene tranduced MCA cell % (MCA-tk%) and uptakes of radiolabeled IVDU or IVFRU. MCA-tk cell expressed HSV1-tk mRNA and HSV1-TK protein. Two compounds showed minimal uptake in MCA, but increased uptake was observed in MCA-tk. IVDU showed 4-fold higher accumulation than IVFRU at 480 min in MCA-tk (p<0.01). Both IVDU and IVFRU uptake were linearly correlated (R{sup 2}>0.96) with increasing MCA-tk%. The rediolabeld IVDU and IVFRU showed higher specific accumulation in retrovirally HSV1-tk gene transfected Morris hepatoma cell line. Both IVDU and IVFRU could be used as good substrates for evaluation of HSV1-tk gene expression.

Linezolid susceptibility in Helicobacter pylori, including strains with multidrug resistance.

Science.gov (United States)

Boyanova, Lyudmila; Evstatiev, Ivailo; Gergova, Galina; Yaneva, Penka; Mitov, Ivan

2015-12-01

Only a few studies have evaluated Helicobacter pylori susceptibility to linezolid. The aim of the present study was to assess linezolid susceptibility in H. pylori, including strains with double/multidrug resistance. The susceptibility of 53 H. pylori strains was evaluated by Etest and a breakpoint susceptibility testing method. Helicobacter pylori resistance rates were as follows: amoxicillin, 1.9%; metronidazole, 37.7%; clarithromycin, 17.0%; tetracycline, 1.9%; levofloxacin, 24.5%; and linezolid (>4 mg/L), 39.6%. The linezolid MIC50 value was 31.2-fold higher than that of clarithromycin and 10.5-fold higher than that of levofloxacin; however, 4 of 11 strains with double/multidrug resistance were linezolid-susceptible. The MIC range of the oxazolidinone agent was larger (0.125-64 mg/L) compared with those in the previous two reports. The linezolid resistance rate was 2.2-fold higher in metronidazole-resistant strains and in strains resistant to at least one antibiotic compared with the remaining strains. Briefly, linezolid was less active against H. pylori compared with clarithromycin and levofloxacin, and linezolid resistance was linked to resistance to metronidazole as well as to resistance to at least one antibiotic. However, linezolid activity against some strains with double/multidrug resistance may render the agent appropriate to treat some associated H. pylori infections following in vitro susceptibility testing of the strains. Clinical trials are required to confirm this suggestion. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

The X protein of hepatitis B virus activates hepatoma cell proliferation through repressing melanoma inhibitory activity 2 gene

Energy Technology Data Exchange (ETDEWEB)

Xu, Yilin; Yang, Yang; Cai, Yanyan; Liu, Fang; Liu, Yingle; Zhu, Ying [State Key Laboratory of Virology, College of Life Sciences, and Chinese-French Liver Disease Research Institute at Zhongnan Hospital, Wuhan University, Wuhan 430072 (China); Wu, Jianguo, E-mail: jwu@whu.edu.cn [State Key Laboratory of Virology, College of Life Sciences, and Chinese-French Liver Disease Research Institute at Zhongnan Hospital, Wuhan University, Wuhan 430072 (China)

2011-12-16

Highlights: Black-Right-Pointing-Pointer We demonstrated that HBV represses MIA2 gene expression both invitro and in vivo. Black-Right-Pointing-Pointer The X protein of HBV plays a major role in such regulation. Black-Right-Pointing-Pointer Knock-down of MIA2 in HepG2 cells activates cell growth and proliferation. Black-Right-Pointing-Pointer HBx activates cell proliferation, over-expression of MIA2 impaired such regulation. Black-Right-Pointing-Pointer HBx activates hepatoma cell proliferation through repressing MIA2 expression. -- Abstract: Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer deaths globally. Chronic hepatitis B virus (HBV) infection accounts for over 75% of all HCC cases; however, the molecular pathogenesis of HCC is not well understood. In this study, we found that the expression of the newly identified gene melanoma inhibitory activity 2 (MIA2) was reduced by HBV infection invitro and invivo, and that HBV X protein (HBx) plays a major role in this regulation. Recent studies have revealed that MIA2 is a potential tumor suppressor, and that, in most HCCs, MIA2 expression is down-regulated or lost. We found that the knock-down of MIA2 in HepG2 cells activated cell growth and proliferation, suggesting that MIA2 inhibits HCC cell growth and proliferation. In addition, the over-expression of HBx alone induced cell proliferation, whereas MIA2 over-expression impaired the HBx-mediated induction of proliferation. Taken together, our results suggest that HBx activates hepatoma cell growth and proliferation through repression of the potential tumor suppressor MIA2.

Increased multi-drug resistant Escherichia coli from hospitals in ...

African Journals Online (AJOL)

Background: Multidrug-resistant Escherichia coli (MDR E. coli) has become a major public health concern in Sudan and many countries, causing failure in treatment with consequent huge health burden. Objectives: To determine the prevalence and susceptibility of MDR E. coli isolated from patients in hospitals at Khartoum ...

Characterization of the cDNA encoding human nucleophosmin and studies of its role in normal and abnormal growth

International Nuclear Information System (INIS)

Chan, Waiyee; Liu, Qingrong; Borjigin, J.; Busch, H.; Rennert, O.M.; Tease, L.A.; Chan, Puikwong

1989-01-01

A cDNA encoding human nucleophosmin (protein B23) was obtained by screening a human placental cDNA library in δgtll first with monoclonal antibody to rat nucleophosmin and then with confirmed partial cDNA of human nucleophosmin as probes. The cDNA had 1,311 bp with a coding sequence encoding a protein of 294 amino acids. The identity of the cDNA was confirmed by the presence of encoded amino acid sequences identical with those determined by sequencing pure rat nucleophosmin (a total of 138 amino acids). The most striking feature of the sequence is an acidic cluster located in the middle of the molecule. The cluster consists of 26 Asp/Glu and 1 Phe and Ala. Comparison of human nucleophosmin and Xenopus nucleolar protein NO38 shows 64.3% sequence identity. The N-terminal 130 amino acids of human nucleophosmin also bear 50% identity with that of Xenopus nucleoplasmin. Northern blot analysis of rat liver total RNA with a partial nucleophosmin cDNA as probe demonstrated a homogeneous mRNA band of about 1.6 kb. Similar observations were made in hypertrophic rat liver and Novikoff hepatoma. When the protein levels were compared with Western blot immunoassays, Navikoff hepatoma showed 20 times more nucleophosmin, while only about 5 times more nucleophosmin was observed in hypertrophic rat liver than in unstimulated normal liver

R-Flurbiprofen Traps Prostaglandins within Cells by Inhibition of Multidrug Resistance-Associated Protein-4.

Science.gov (United States)

Wobst, Ivonne; Ebert, Lisa; Birod, Kerstin; Wegner, Marthe-Susanna; Hoffmann, Marika; Thomas, Dominique; Angioni, Carlo; Parnham, Michael J; Steinhilber, Dieter; Tegeder, Irmgard; Geisslinger, Gerd; Grösch, Sabine

2016-12-30

R -flurbiprofen is the non-COX-inhibiting enantiomer of flurbiprofen and is not converted to S -flurbiprofen in human cells. Nevertheless, it reduces extracellular prostaglandin E₂ (PGE₂) in cancer or immune cell cultures and human extracellular fluid. Here, we show that R -flurbiprofen acts through a dual mechanism: (i) it inhibits the translocation of cPLA 2α to the plasma membrane and thereby curtails the availability of arachidonic acid and (ii) R -flurbiprofen traps PGE₂ inside of the cells by inhibiting multidrug resistance-associated protein 4 (MRP4, ABCC4), which acts as an outward transporter for prostaglandins. Consequently, the effects of R -flurbiprofen were mimicked by RNAi-mediated knockdown of MRP4. Our data show a novel mechanism by which R -flurbiprofen reduces extracellular PGs at physiological concentrations, particularly in cancers with high levels of MRP4, but the mechanism may also contribute to its anti-inflammatory and immune-modulating properties and suggests that it reduces PGs in a site- and context-dependent manner.

[Molecular mechanism of cisplatin to enhance the ability of TRAIL in reversing multidrug resistance in gastric cancer cells].

Science.gov (United States)

Zhu, Xingchao; Zhang, Kaiguang; Wang, Qiaomin; Chen, Si; Gou, Yawen; Cui, Yufang; Li, Qin

2015-06-01

To study the molecular mechanism of cisplatin to enhance the ability of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in reversing multidrug resistance in vincristine-resistant human gastric cancer SGC7901/VCR cells. MTT assay was used to measure the 50% inhibiting concentration (IC₅₀) and cell survival in SGC7901 and SGC7901/VCR cells after different treatments. SGC7901/VCR cells were treated with different concentrations of DDP, different concentrations of TRAIL alone or in combination, and then the mRNA and protein levels of several genes were determined by RT-PCR, RT-qPCR and Western-blot analysis. After targeted silencing with specific siRNA and transfection of recombinant plasmid c-myc into the SGC7901/VCR cells, the mRNA and protein levels of DR4, DR5 and c-myc were determined by RT-PCR and Western-blot analysis. After combined treatment with TRAIL and DDP of the SGC7901/VCR cells, the IC₅₀ of VCR, DDP, ADM, and 5-Fu treatment was significantly decreased compared with the control group or TRAIL-treated group (P mechanism of DDP-induced sensitization of TRAIL to reverse the multidrug resistancein SGC7901/VCR cells.

Infection by multidrug-resistant Elizabethkingia meningoseptica: case reports

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Jailton Lobo da Costa Lima

2014-12-01

Full Text Available We report two cases of sepsis in critically ill patients in two tertiary care hospitals in Recife-PE, Brazil. The first case is an 87-year-old patient with chronic myeloid leukemia and sepsis; and the second case is a 93-year-old patient with prostate cancer and septic shock caused by multidrug-resistant (MDR Elizabethkingia meningoseptica.

Characterization of putative multidrug resistance transporters of the major facilitator-superfamily expressed in Salmonella Typhi

DEFF Research Database (Denmark)

Shaheen, Aqsa; Ismat, Fouzia; Iqbal, Mazhar

2015-01-01

Multidrug resistance mediated by efflux pumps is a well-known phenomenon in infectious bacteria. Although much work has been carried out to characterize multidrug efflux pumps in Gram-negative and Gram-positive bacteria, such information is still lacking for many deadly pathogens. The aim...... of this study was to gain insight into the substrate specificity of previously uncharacterized transporters of Salmonella Typhi to identify their role in the development of multidrug resistance. S. Typhi genes encoding putative members of the major facilitator superfamily were cloned and expressed in the drug......-hypersensitive Escherichia coli strain KAM42, and tested for transport of 25 antibacterial compounds, including representative antibiotics of various classes, antiseptics, dyes and detergents. Of the 15 tested putative transporters, STY0901, STY2458 and STY4874 exhibited a drug-resistance phenotype. Among these, STY4874...

Mitochondrial oxidative stress in human hepatoma cells exposed to stavudine

International Nuclear Information System (INIS)

Velsor, Leonard W.; Kovacevic, Miro; Goldstein, Mark; Leitner, Heather M.; Lewis, William; Day, Brian J.

2004-01-01

The toxicity of nucleoside reverse transcriptase inhibitors (NRTIs) is linked to altered mitochondrial DNA (mtDNA) replication and subsequent disruption of cellular energetics. This manifests clinically as elevated concentrations of lactate in plasma. The mechanism(s) underlying how the changes in mtDNA replication lead to lactic acidosis remains unclear. It is hypothesized that mitochondrial oxidative stress links the changes in mtDNA replication to mitochondrial dysfunction and ensuing NRTIs toxicity. To test this hypothesis, changes in mitochondrial function, mtDNA amplification efficiency, and oxidative stress were assessed in HepG2-cultured human hepatoblasts treated with the NRTI stavudine (2',3'-didehydro-2',3'-deoxythymidine or d4T) for 48 h. d4T produced significant mitochondrial dysfunction with a 1.5-fold increase in cellular lactate to pyruvate ratios. In addition, d4T caused a dose-dependent decrease in mtDNA amplification and a correlative increase in abundance of markers of mitochondrial oxidative stress. Manganese (III) meso-tetrakis (4-benzoic acid) porphyrin, MnTBAP, a catalytic antioxidant, ameliorated or reversed d4T-induced changes in cell injury, energetics, mtDNA amplification, and mitochondrial oxidative stress. In conclusion, d4T treatment elevates mitochondrial reactive oxygen species (ROS), enhances mitochondrial oxidative stress, and contributes mechanistically to NRTI-induced toxicity. These deleterious events may be potentiated in acquired immunodeficiency syndrome (AIDS) by human immunodeficiency virus (HIV) infection itself, coinfection (e.g., viral hepatitis), aging, substance, and alcohol use

Anticancer Effects of the Nitric Oxide-Modified Saquinavir Derivative Saquinavir-NO against Multidrug-Resistant Cancer Cells

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Florian Rothweiler

2010-12-01

Full Text Available The human immunodeficiency virus (HIV protease inhibitor saquinavir shows anticancer activity. Although its nitric oxide-modified derivative saquinavir-NO (saq-NO was less toxic to normal cells, it exerted stronger inhibition of B16 melanoma growth in syngeneic C57BL/6 mice than saquinavir did. Saq-NO has been shown to block proliferation, upregulate p53 expression, and promote differentiation of C6 glioma and B16 cells. The anticancer activity of substances is frequently hampered by cancer cell chemoresistance mechanisms. Therefore, we here investigated the roles of p53 and the ATP-binding cassette (ABC transporters P-glycoprotein (P-gp, multidrug resistance-associated protein 1 (MRP1, and breast cancer resistance protein 1 (BCRP1 in cancer cell sensitivity to saq-NO to get more information about the potential of saq-NO as anticancer drug. Saq-NO exerted anticancer effects in lower concentrations than saquinavir in a panel of human cancer cell lines. Neither p53 mutation or depletion nor expression of P-gp, MRP1, or BCRP1 affected anticancer activity of saq-NO or saquinavir. Moreover, saq-NO sensitized P-gp-, MRP1-, or BCRP1-expressing cancer cells to chemotherapy. Saq-NO induced enhanced sensitization of P-gp- or MRP1-expressing cancer cells to chemotherapy compared with saquinavir, whereas both substances similarly sensitized BCRP1-expressing cells. Washout kinetics and ABC transporter ATPase activities demonstrated that saq-NO is a substrate of P-gp as well as of MRP1. These data support the further investigation of saq-NO as an anticancer drug, especially in multidrug-resistant tumors.

Impact of Infection Control Measures to Control an Outbreak of Multidrug-Resistant Tuberculosis in a Human Immunodeficiency Virus Ward, Peru

Science.gov (United States)

Ticona, Eduardo; Huaroto, Luz; Kirwan, Daniela E.; Chumpitaz, Milagros; Munayco, César V.; Maguiña, Mónica; Tovar, Marco A.; Evans, Carlton A.; Escombe, Roderick; Gilman, Robert H.

2016-01-01

Multidrug-resistant tuberculosis (MDRTB) rates in a human immunodeficiency virus (HIV) care facility increased by the year 2000—56% of TB cases, eight times the national MDRTB rate. We reported the effect of tuberculosis infection control measures that were introduced in 2001 and that consisted of 1) building a respiratory isolation ward with mechanical ventilation, 2) triage segregation of patients, 3) relocation of waiting room to outdoors, 4) rapid sputum smear microscopy, and 5) culture/drug–susceptibility testing with the microscopic-observation drug-susceptibility assay. Records pertaining to patients attending the study site between 1997 and 2004 were reviewed. Six hundred and fifty five HIV/TB–coinfected patients (mean age 33 years, 79% male) who attended the service during the study period were included. After the intervention, MDRTB rates declined to 20% of TB cases by the year 2004 (P = 0.01). Extremely limited access to antiretroviral therapy and specific MDRTB therapy did not change during this period, and concurrently, national MDRTB prevalence increased, implying that the infection control measures caused the fall in MDRTB rates. The infection control measures were estimated to have cost US$91,031 while preventing 97 MDRTB cases, potentially saving US$1,430,026. Thus, this intervention significantly reduced MDRTB within an HIV care facility in this resource-constrained setting and should be cost-effective. PMID:27621303

Population-level genomics identifies the emergence and global spread of a human transmissible multidrug-resistant nontuberculous mycobacterium

Science.gov (United States)

Rodriguez-Rincon, Daniela; Everall, Isobel; Brown, Karen P; Moreno, Pablo; Verma, Deepshikha; Hill, Emily; Drijkoningen, Judith; Gilligan, Peter; Esther, Charles R; Noone, Peadar G; Giddings, Olivia; Bell, Scott C.; Thomson, Rachel; Wainwright, Claire E.; Coulter, Chris; Pandey, Sushil; Wood, Michelle E; Stockwell, Rebecca E; Ramsay, Kay A; Sherrard, Laura J; Kidd, Timothy J; Jabbour, Nassib; Johnson, Graham R; Knibbs, Luke D; Morawska, Lidia; Sly, Peter D; Jones, Andrew; Bilton, Diana; Laurenson, Ian; Ruddy, Michael; Bourke, Stephen; Bowler, Ian CJW; Chapman, Stephen J; Clayton, Andrew; Cullen, Mairi; Daniels, Thomas; Dempsey, Owen; Denton, Miles; Desai, Maya; Drew, Richard J; Edenborough, Frank; Evans, Jason; Folb, Jonathan; Humphrey, Helen; Isalska, Barbara; Jensen-Fangel, Søren; Jönsson, Bodil; Jones, Andrew M.; Katzenstein, Terese L; Lillebaek, Troels; MacGregor, Gordon; Mayell, Sarah; Millar, Michael; Modha, Deborah; Nash, Edward F; O’Brien, Christopher; O’Brien, Deirdre; Ohri, Chandra; Pao, Caroline S; Peckham, Daniel; Perrin, Felicity; Perry, Audrey; Pressler, Tania; Prtak, Laura; Qvist, Tavs; Robb, Ali; Rodgers, Helen; Schaffer, Kirsten; Shafi, Nadia; van Ingen, Jakko; Walshaw, Martin; Watson, Danie; West, Noreen; Whitehouse, Joanna; Haworth, Charles S; Harris, Simon R; Ordway, Diane; Parkhill, Julian; Floto, R. Andres

2016-01-01

Lung infections with Mycobacterium abscessus, a species of multidrug resistant nontuberculous mycobacteria, are emerging as an important global threat to individuals with cystic fibrosis (CF) where they accelerate inflammatory lung damage leading to increased morbidity and mortality. Previously, M. abscessus was thought to be independently acquired by susceptible individuals from the environment. However, using whole genome analysis of a global collection of clinical isolates, we show that the majority of M. abscessus infections are acquired through transmission, potentially via fomites and aerosols, of recently emerged dominant circulating clones that have spread globally. We demonstrate that these clones are associated with worse clinical outcomes, show increased virulence in cell-based and mouse infection models, and thus represent an urgent international infection challenge. PMID:27846606

Multidrug therapy for leprosy: a game changer on the path to elimination.

Science.gov (United States)

Smith, Cairns S; Aerts, Ann; Saunderson, Paul; Kawuma, Joseph; Kita, Etsuko; Virmond, Marcos

2017-09-01

Leprosy is present in more than 100 countries, where it remains a major cause of peripheral neuropathy and disability. Attempts to eliminate the disease have faced various obstacles, including characteristics of the causative bacillus Mycobacterium leprae: the long incubation period, limited knowledge about its mode of transmission, and its poor growth on culture media. Fortunately, the leprosy bacillus is sensitive to several antibiotics. The first antibiotic to be widely used for leprosy treatment was dapsone in the 1950s, which had to be taken over several years and was associated with increasing bacterial resistance. Therefore, in 1981, WHO recommended that all registered patients with leprosy should receive combination therapy with three antibiotics: rifampicin, clofazimine, and dapsone. Global implementation of this highly effective multidrug therapy took about 15 years. In 1985, 5·3 million patients were receiving multidrug therapy; by 1991, this figure had decreased to 3·1 million (a decrease of 42%) and, by 2000, to 597 232 (a decrease of almost 90%). This reduction in the number of patients registered for treatment was due to shortening of the treatment regimen and achievement of 100% coverage with multidrug therapy. This achievement, which owed much to WHO and the donors of the multidrug therapy components, prompted WHO in 1991 to set a global target of less than one case per 10 000 population by 2000 to eliminate the disease as a public health problem. All but 15 countries achieved this target. Since 2000, about 250 000 new cases of leprosy have been detected every year. We believe an all-out campaign by a global leprosy coalition is needed to bring that figure down to zero. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thyroid hormone receptor inhibits hepatoma cell migration through transcriptional activation of Dickkopf 4

Energy Technology Data Exchange (ETDEWEB)

Chi, Hsiang-Cheng; Liao, Chen-Hsin [Department of Biochemistry, School of Medicine, Chang-Gung University, Taoyuan 333, Taiwan, ROC (China); Huang, Ya-Hui [Medical Research Central, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan, ROC (China); Wu, Sheng-Ming; Tsai, Chung-Ying; Liao, Chia-Jung; Tseng, Yi-Hsin; Lin, Yang-Hsiang; Chen, Cheng-Yi; Chung, I-Hsiao; Wu, Tzu-I [Department of Biochemistry, School of Medicine, Chang-Gung University, Taoyuan 333, Taiwan, ROC (China); Chen, Wei-Jan [First Cardiovascular Division, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan, ROC (China); Lin, Kwang-Huei, E-mail: khlin@mail.cgu.edu.tw [Department of Biochemistry, School of Medicine, Chang-Gung University, Taoyuan 333, Taiwan, ROC (China)

2013-09-13

Highlights: •T{sub 3} affects DKK4 mRNA and protein expression in HepG2-TR cells. •Regulation of DKK4 by T{sub 3} is at transcriptional level. •DKK4 overexpression suppresses hepatoma cell metastasis. -- Abstract: Triiodothyronine (T{sub 3}) is a potent form of thyroid hormone mediates several physiological processes including cellular growth, development, and differentiation via binding to the nuclear thyroid hormone receptor (TR). Recent studies have demonstrated critical roles of T{sub 3}/TR in tumor progression. Moreover, long-term hypothyroidism appears to be associated with the incidence of human hepatocellular carcinoma (HCC), independent of other major HCC risk factors. Dickkopf (DKK) 4, a secreted protein that antagonizes the canonical Wnt signaling pathway, is induced by T{sub 3} at both mRNA and protein levels in HCC cell lines. However, the mechanism underlying T{sub 3}-mediated regulation of DKK4 remains unknown. In the present study, the 5′ promoter region of DKK4 was serially deleted, and the reporter assay performed to localize the T{sub 3} response element (TRE). Consequently, we identified an atypical direct repeat TRE between nucleotides −1645 and −1629 conferring T{sub 3} responsiveness to the DKK4 gene. This region was further validated using chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). Stable DKK4 overexpression in SK-Hep-1 cells suppressed cell invasion and metastatic potential, both in vivo andin vitro, via reduction of matrix metalloproteinase-2 (MMP-2) expression. Our findings collectively suggest that DKK4 upregulated by T{sub 3}/TR antagonizes the Wnt signal pathway to suppress tumor cell progression, thus providing new insights into the molecular mechanism underlying thyroid hormone activity in HCC.

Nano-hole induction by nanodiamond and nanoplatinum liquid, DPV576, reverses multidrug resistance in human myeloid leukemia (HL60/AR

Directory of Open Access Journals (Sweden)

Ghoneum A

2013-07-01

Full Text Available Alia Ghoneum,1,2 Shivani Sharma,1,3 James Gimzewsk1,3 1Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, 2Department of Otalaryngology, Drew University of Medicine and Science, Los Angeles, 3California Nanosystems Institute (CNSI at University of California, Los Angeles, Los Angeles, CA, USA Abstract: Recently nanoparticles have been extensively studied and have proven to be a promising candidate for cancer treatment and diagnosis. In the current study, we examined the chemo-sensitizing activity of a mixture of nanodiamond (ND and nanoplatinum (NP solution known as DPV576, against multidrug-resistant (MDR human myeloid leukemia (HL60/AR and MDR-sensitive cells (HL60. Cancer cells were cultured with different concentrations of daunorubicin (DNR (1 × 10-9–1 × 10-6 M in the presence of selected concentrations of DPV576 (2.5%–10% v/v. Cancer cell survival was determined by MTT assay, drug accumulation by flow cytometry and confocal laser scanning microscopy (CLSM, and holes and structural changes by atomic force microscopy (AFM. Co-treatment of HL60/AR cells with DNR plus DPV576 resulted in the reduction of the IC50 to 1/4th. This was associated with increased incidences of holes inside the cells as compared with control untreated cells. On the other hand, HL60 cells did not show changes in their drug accumulation post-treatment with DPV576 and DNR. We conclude that DPV576 is an effective chemo-sensitizer as indicated by the reversal of HL60/AR cells to DNR and may represent a potential novel adjuvant for the treatment of chemo-resistant human myeloid leukemia. Keywords: nanodiamond, nanoplatinum, daunorubicin, flow cytometry, AFM

The spleen can influence the metastasis of AH130 hepatoma cells in rats.

Science.gov (United States)

Toyonaga, M; Hiraoka, T; Tanaka, H; Miyauchi, Y

1993-06-01

The effect of pathophysiological conditions due to disturbance of the spleen is still unclear. We studied the effects of splenectomy in normal and methylcellulose-induced hypersplenic rats on the development of pulmonary metastases created by intravenous injection of ascites containing AH130 hepatoma cells from male Hos-Donryu rats. Growth of metastatic lesions in the lung was not affected by splenectomy in normal rats, but was increased by splenectomy in hypersplenic rats. Overall, there were fewer pulmonary metastases in rats with hypersplenism, but after splenectomy rats with hypersplenism had a significantly greater number of metastases than did normal rats. The metastases rate correlated somewhat with changes in the blood coagulation and T lymphocyte profile. There is a relationship between the spleen and formation of metastases in cancer. Formation of metastases in the lung was affected most by splenectomy in hypersplenism. To elucidate the mechanism by which metastases are formed in the lung under these pathologic conditions, further studies on the exact role of the spleen are required.

Case of radiation gastroduodenitis caused by /sup 60/Co-irradiation therapy for hepatoma

Energy Technology Data Exchange (ETDEWEB)

Nishikawa, H; Hayashi, N; Morise, K; Tunekawa, J; Kaneshiro, K [Nagoya Univ. (Japan). Faculty of Medicine

1981-02-01

A 56-year-old man with hepatoma, who had been treated with total 3,960 rad of /sup 60/Co-irradiation 2 months previously, was readmitted to the hospital because of fever and anemia. Following admission, he passed tarry stools every day. Barium meal examination revealed esophageal varices and erosive gastritis of the antrum. At endoscopy, many hemorrhagic erosions were found in the gastric antrum and the first part of duodenum, which were located in the irradiation area. Since repeated blood transfusion failed to improve anemia, a complete fasting with intravenous hyperalimentation and antacid therapy were started. Two months later, feeding was started and thereafter continued without any appreciable GI bleeding or worsening of anemia. Endoscopic examination at this time revealed only a few erosions scattered over the edematous antral mucosa as well as the proximal duodenum. IVH, antacids and abstinence from food seem to be an effective measure in the treatment of radiation injury of the gut.

Isolation and characterization of antimicrobial compounds in plant extracts against multidrug-resistant Acinetobacter baumannii.

Directory of Open Access Journals (Sweden)

Yoko Miyasaki

Full Text Available The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against A. baumannii. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in Rosa rugosa; norwogonin in Scutellaria baicalensis; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in Terminalia chebula. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of A. baumannii. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant A. baumannii strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant A. baumannii.

Prevalence of multidrug resistant pathogens in children with urinary tract infection: a retrospective analysis

Directory of Open Access Journals (Sweden)

Srinivasan S, Madhusudhan NS

2014-11-01

Full Text Available Urinary tract infection (UTI is one of the commonest medical problems in children. It can distress the child and may cause kidney damage. Prompt diagnosis and effective treatment can prevent complications in the child. But treatment of UTI in children has now become a challenge due to the emergence of multidrug resistant bacteria. Aims & Objectives: To know the bacteriological profile and susceptibility pattern of urinary tract infections in children and to know the prevalence of multidrug resistant uropathogens. Materials & Methods: A retrospective analysis was done on all paediatric urine samples for a period of one year. A total of 1581 samples were included in the study. Antimicrobial susceptibility testing was done on samples showing significant growth by Kirby-Bauer disc diffusion method. Statistical analysis: Prevalence and pattern were analyzed using proportions and percentages. Results: E.coli was the most predominant organism (56% causing UTI in children followed by Klebsiella sp (17%. Fifty three percent of gram negative organisms isolated from children were found to be multidrug resistant. Majority of E. coli isolates were found to be highly resistant to Ampicillin (91% and Cotrimoxazole (82% and highly sensitive to Imipenem (99% and Amikacin (93%. Conclusion: Paediatric UTI was common in children less than 5 years of age. Gram negative bacteria (E. coli and Klebsiella sp were more common than gram positive bacteria. Our study revealed that multidrug resistance was higher in E.coli.

A yeast endoribonuclease stimulated by Novikoff hepatoma small nuclear RNAs U1 and U2

International Nuclear Information System (INIS)

Stevens, A.

1982-01-01

Using [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) from yeast as a substrate, an endoribonuclease has been detected in enzyme fractions derived from a high salt wash of ribonucleoprotein particles of Saccharomyces cerevisiae. The [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) seems to be a preferred substrate since other polyribonucleotides are hydrolyzed more slowly, if at all. The enzyme is inhibited by ethidium bromide, but fully double-stranded polyribonucleotides are not hydrolyzed. The hydrolysis of [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) is stimulated about 2.5-fold by the addition of small nuclear RNAs U1 and U2 of Novikoff hepatoma cells. Results show that the stimulation involves an interaction of the labeled RNA with the small nuclear RNA

Clinical and biological significance of hepatoma-derived growth factor in Ewing's sarcoma.

Science.gov (United States)

Yang, Yang; Li, Hui; Zhang, Fenfen; Shi, Huijuan; Zhen, Tiantian; Dai, Sujuan; Kang, Lili; Liang, Yingjie; Wang, Jin; Han, Anjia

2013-11-01

We sought to investigate the clinicopathological significance and biological function of hepatoma-derived growth factor (HDGF) in Ewing's sarcoma. Our results showed that HDGF expression is up-regulated in Ewing's sarcoma. Nuclear HDGF expression is significantly associated with tumour volume (p Ewing's sarcoma cell growth, proliferation and enhances tumourigenesis, both in vitro and in vivo. Meanwhile, HDGF knock-down causes cell cycle arrest and enhanced sensitization to serum starvation-induced apoptosis. Furthermore, recombinant HDGF promotes proliferation and colony formation of Ewing's sarcoma cells. Ninety-eight candidate HDGF downstream genes were identified in Ewing's sarcoma cells using cDNA microarray analysis. In addition, we found that HDGF knock-down inhibited FLI1 expression in Ewing's sarcoma cells at the mRNA and protein levels. Our findings suggest that HDGF exhibits oncogenic properties and may be a novel prognostic factor in Ewing's sarcoma. Targeting HDGF might be a potential therapeutic strategy for Ewing's sarcoma. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Optimizing the Safety of Multidrug-resistant Tuberculosis Therapy in Namibia

NARCIS (Netherlands)

Sagwa, Evans

2017-01-01

Introduction: Multidrug-resistant tuberculosis (MDR-TB), a growing global menace, is seriously undermining the previous successes made in the elimination of TB. MDR-TB treatment takes a long time, is complex, and is frequently associated with the occurrence of adverse drug reactions, some of which

Multidrug-resistant tuberculosis in pregnancy

International Nuclear Information System (INIS)

Dhingra, V.K.; Arora, V.K.; Rajpal, S.

2007-01-01

This is a case report of 26 years old pregnant woman with multidrug-resistant tuberculosis (MDR TB), treated at outpatient department of New Delhi Tuberculosis (NDTB) Centre, India with second line agents. Before presentation at NDTB Centre, she had been treated with first line drugs for approximately one and-a-half-year, including category II re-treatment DOTS regimen under RNTCP. Patient conceived twice during her anti-TB treatment. The first one was during her category II treatment, when put on second line drugs. We describe congenital abnormalities documented in her second child exposed in-utero to second line anti-tubercular drugs with a brief review of treatment of MDR TB in pregnancy. (author)

Mixture model to assess the extent of cross-transmission of multidrug-resistant pathogens in hospitals.

Science.gov (United States)

Mikolajczyk, Rafael T; Kauermann, Göran; Sagel, Ulrich; Kretzschmar, Mirjam

2009-08-01

Creation of a mixture model based on Poisson processes for assessment of the extent of cross-transmission of multidrug-resistant pathogens in the hospital. We propose a 2-component mixture of Poisson processes to describe the time series of detected cases of colonization. The first component describes the admission process of patients with colonization, and the second describes the cross-transmission. The data set used to illustrate the method consists of the routinely collected records for methicillin-resistant Staphylococcus aureus (MRSA), imipenem-resistant Pseudomonas aeruginosa, and multidrug-resistant Acinetobacter baumannii over a period of 3 years in a German tertiary care hospital. For MRSA and multidrug-resistant A. baumannii, cross-transmission was estimated to be responsible for more than 80% of cases; for imipenem-resistant P. aeruginosa, cross-transmission was estimated to be responsible for 59% of cases. For new cases observed within a window of less than 28 days for MRSA and multidrug-resistant A. baumannii or 40 days for imipenem-resistant P. aeruginosa, there was a 50% or greater probability that the cause was cross-transmission. The proposed method offers a solution to assessing of the extent of cross-transmission, which can be of clinical use. The method can be applied using freely available software (the package FlexMix in R) and it requires relatively little data.

Genetic diversity of drug and multidrug-resistant Mycobacterium tuberculosis circulating in Veracruz, Mexico

Science.gov (United States)

Munro-Rojas, Daniela; Fernandez-Morales, Esdras; Zarrabal-Meza, José; Martínez-Cazares, Ma. Teresa; Parissi-Crivelli, Aurora; Fuentes-Domínguez, Javier; Séraphin, Marie Nancy; Lauzardo, Michael; González-y-Merchand, Jorge Alberto; Rivera-Gutierrez, Sandra

2018-01-01

Background Mexico is one of the most important contributors of drug and multidrug-resistant tuberculosis in Latin America; however, knowledge of the genetic diversity of drug-resistant tuberculosis isolates is limited. Methods In this study, the genetic structure of 112 Mycobacterium tuberculosis strains from the southeastern Mexico was determined by spoligotyping and 24-loci MIRU-VNTRs. Findings The results show eight major lineages, the most of which was T1 (24%), followed by LAM (16%) and H (15%). A total of 29 (25%) isolates were identified as orphan. The most abundant SITs were SIT53/T1 and SIT42/LAM9 with 10 isolates each and SIT50/H3 with eight isolates. Fifty-two spoligotype patterns, twenty-seven clusters and ten clonal complexes were observed, demonstrating an important genetic diversity of drug and multidrug-resistant tuberculosis isolates in circulation and transmission level of these aggravated forms of tuberculosis. Being defined as orphan or as part of an orphan cluster, was a risk factor for multidrug resistant-tuberculosis (OR 2.5, IC 1.05–5.86 and OR 3.3, IC 1–11.03, respectively). Multiple correspondence analyses showed association of some clusters and SITs with specific geographical locations. Conclusions Our study provides one of the most detailed description of the genetic structure of drug and multidrug-resistant tuberculosis strains in southeast Mexico, establishing for the first time a baseline of the genotypes observed in resistant isolates circulating, however further studies are required to better elucidate the genetic structure of tuberculosis in region and the factors that could be participating in their dispersion. PMID:29543819

A case of multidrug-resistant monoarticular joint tuberculosis in a renal transplant recipient.

Science.gov (United States)

Regmi, A; Singh, P; Harford, A

2014-01-01

Tuberculosis (TB) is a common opportunistic infection after renal transplantation. The risk of TB in renal transplant recipients is reported to be 20 to 74 times higher than in the general population. Although extrapulmonary TB occurs frequently, isolated ankle joint TB is a rare form of extrapulmonary TB infection. It is often difficult to diagnose because of its atypical presentation; management is complex, especially with multidrug-resistant TB, the need for a prolonged course of therapy, and the risks of drug interactions and drug toxicity. We report herein a case of a 60-year-old female renal allograft recipient who developed multidrug-resistant ankle joint TB 11 months after her deceased donor renal transplantation. She presented to the emergency department with escalating pain and swelling of the left ankle, difficulty in ambulation, and a low-grade fever. An x-ray of the ankle revealed an effusion and soft tissue swelling. A synovial fluid culture was performed which tested positive for acid fast bacilli which grew a multidrug-resistant form of Mycobacterium tuberculosis. She was initially treated with isoniazid, rifampin, ethambutol, and pyrazinamide; then therapy was tailored secondary to the resistant nature of the organism. She received a combination of extensive debridement of the joint and institution of second-line anti-TB therapy with pyrazinamide, ethambutol, moxifloxacin, and ethionamide. To our knowledge, no other cases of multidrug-resistant TB have been reported in the literature after renal transplantation. This case shows both an atypical presentation of TB and the difficulties in managing a transplant patient with this disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Candida auris: An emerging multidrug-resistant pathogen

Directory of Open Access Journals (Sweden)

David Sears

2017-10-01

Full Text Available Candida aurisis an emerging multidrug-resistant pathogen that can be difficult to identify using traditional biochemical methods. C. auris is capable of causing invasive fungal infections, particularly among hospitalized patients with significant medical comorbidities. Echinocandins are the empiric drugs of choice for C. auris, although not all isolates are susceptible and resistance may develop on therapy. Nosocomial C. auris outbreaks have been reported in a number of countries and aggressive infection control measures are paramount to stopping transmission.

Functional study of the novel multidrug resistance gene HA117 and its comparison to multidrug resistance gene 1

Directory of Open Access Journals (Sweden)

Chen Tingfu

2010-07-01

Full Text Available Abstract Background The novel gene HA117 is a multidrug resistance (MDR gene expressed by all-trans retinoic acid-resistant HL-60 cells. In the present study, we compared the multidrug resistance of the HA117 with that of the classical multidrug resistance gene 1 (MDR1 in breast cancer cell line 4T1. Methods Transduction of the breast cancer cell line 4T1 with adenoviral vectors encoding the HA117 gene and the green fluorescence protein gene (GFP (Ad-GFP-HA117, the MDR1 and GFP (Ad-GFP-MDR1 or GFP (Ad-GFP was respectively carried out. The transduction efficiency and the multiplicity of infection (MOI were detected by fluorescence microscope and flow cytometry. The transcription of HA117 gene and MDR1 gene were detected by reverse transcription polymerase chain reaction (RT-PCR. Western blotting analysis was used to detect the expression of P-glycoprotein (P-gp but the expression of HA117 could not be analyzed as it is a novel gene and its antibody has not yet been synthesized. The drug-excretion activity of HA117 and MDR1 were determined by daunorubicin (DNR efflux assay. The drug sensitivities of 4T1/HA117 and 4T1/MDR1 to chemotherapeutic agents were detected by Methyl-Thiazolyl-Tetrazolium (MTT assay. Results The transducted efficiency of Ad-GFP-HA117 and Ad-GFP-MDR1 were 75%-80% when MOI was equal to 50. The transduction of Ad-GFP-HA117 and Ad-GFP-MDR1 could increase the expression of HA117 and MDR1. The drug resistance index to Adriamycin (ADM, vincristine (VCR, paclitaxel (Taxol and bleomycin (BLM increased to19.8050, 9.0663, 9.7245, 3.5650 respectively for 4T1/HA117 and 24.2236, 11.0480, 11.3741, 0.9630 respectively for 4T1/MDR1 as compared to the control cells. There were no significant differences in drug sensitivity between 4T1/HA117 and 4T1/MDR1 for the P-gp substrates (ADM, VCR and Taxol (P Conclusions These results confirm that HA117 is a strong MDR gene in both HL-60 and 4T1 cells. Furthermore, our results indicate that the MDR

Synthesis of Nanodiamond-Daunorubicin Conjugates to Overcome Multidrug Chemoresistance in Leukemia

Science.gov (United States)

Man, Han B.; Kim, Hansung; Kim, Ho-Joong; Robinson, Erik; Liu, Wing Kam; Chow, Edward Kai-Hua; Ho, Dean

2013-01-01

Nanodiamonds (NDs) are promising candidates in nanomedicine, demonstrating significant potential as gene/drug delivery platforms for cancer therapy. We have synthesized ND vectors capable of chemotherapeutic loading and delivery with applications towards chemoresistant leukemia. The loading of Daunorubicin (DNR) onto NDs was optimized by adjusting reaction parameters such as acidity and concentration. The resulting conjugate, a novel therapeutic payload for NDs, was characterized extensively for size, surface charge, and loading efficiency. A K562 human myelogenous leukemia cell line, with multidrug resistance conferred by incremental DNR exposure, was used to demonstrate the efficacy enhancement resulting from ND-based delivery. While resistant K562 cells were able to overcome treatment from DNR alone, as compared with non-resistant K562 cells, NDs were able to improve DNR delivery into resistant K562 cells. By overcoming efflux mechanisms present in this resistant leukemia line, ND-enabled therapeutics have demonstrated the potential to improve cancer treatment efficacy, especially towards resistant strains. PMID:23916889

Potential antimicrobial agents for the treatment of multidrug-resistant tuberculosis

NARCIS (Netherlands)

Alsaad, Noor; Wilffert, Bob; van Altena, Richard; de Lange, Wiel C. M.; van der Werf, Tjip S.; Kosterink, Jos G. W.; Alffenaar, Jan-Willem C.

2014-01-01

Treatment of multidrug-resistant (MDR) tuberculosis (TB) is challenging because of the high toxicity of second-line drugs and the longer treatment duration than for drug-susceptible TB patients. In order to speed up novel treatment for MDR-TB, we suggest considering expanding the indications of

Effect of biocides on biofilms of some multidrug resistant clinical ...

African Journals Online (AJOL)

The ability of Escherichia coli and Klebsiella aerogenes to form biofilms was most affected. There was little inhibition of biofilm formation by the biocides on Staphylococcus aureus. This study has shown a relationship between biocide and multidrug resistance. Keywords: Biocides, Multi drug resistance, sodium hypochlorite, ...

Transfer and persistence of a multi-drug resistance plasmid in situ of the infant gut microbiota in the absence of antibiotic treatment

DEFF Research Database (Denmark)

Gumpert, Heidi; Kubicek-Sutherland, Jessica Z.; Porse, Andreas

2017-01-01

lineage was maintained for months, demonstrating that antibiotic resistance genes can disseminate and persist in the gut microbiome; even in absence of antibiotic selection. Furthermore, through in vivo competition assays, we suggest that the resistant transconjugant can persist through a fitness......The microbial ecosystem residing in the human gut is believed to play an important role in horizontal exchange of virulence and antibiotic resistance genes that threatens human health. While the diversity of gut-microorganisms and their genetic content has been studied extensively, high...... infections, as well as the loss and acquisition of plasmids in these lineages during their colonization of the human gut. In particular, we captured the exchange of multidrug resistance genes, and identified a clinically relevant conjugative plasmid mediating the transfer. This resistant transconjugant...

The commensal infant gut meta-mobilome as a potential reservoir for persistent multidrug resistance integrons.

Science.gov (United States)

Ravi, Anuradha; Avershina, Ekaterina; Foley, Steven L; Ludvigsen, Jane; Storrø, Ola; Øien, Torbjørn; Johnsen, Roar; McCartney, Anne L; L'Abée-Lund, Trine M; Rudi, Knut

2015-10-28

Despite the accumulating knowledge on the development and establishment of the gut microbiota, its role as a reservoir for multidrug resistance is not well understood. This study investigated the prevalence and persistence patterns of an integrase gene (int1), used as a proxy for integrons (which often carry multiple antimicrobial resistance genes), in the fecal microbiota of 147 mothers and their children sampled longitudinally from birth to 2 years. The study showed the int1 gene was detected in 15% of the study population, and apparently more persistent than the microbial community structure itself. We found int1 to be persistent throughout the first two years of life, as well as between mothers and their 2-year-old children. Metagenome sequencing revealed integrons in the gut meta-mobilome that were associated with plasmids and multidrug resistance. In conclusion, the persistent nature of integrons in the infant gut microbiota makes it a potential reservoir of mobile multidrug resistance.

Anticancer Effects of the Nitric Oxide-Modified Saquinavir Derivative Saquinavir-NO against Multidrug-Resistant Cancer Cells12

Science.gov (United States)

Rothweiler, Florian; Michaelis, Martin; Brauer, Peter; Otte, Jürgen; Weber, Kristoffer; Fehse, Boris; Doerr, Hans Wilhelm; Wiese, Michael; Kreuter, Jörg; Al-Abed, Yousef; Nicoletti, Ferdinando; Cinatl, Jindrich

2010-01-01

The human immunodeficiency virus (HIV) protease inhibitor saquinavir shows anticancer activity. Although its nitric oxide-modified derivative saquinavir-NO (saq-NO) was less toxic to normal cells, it exerted stronger inhibition of B16 melanoma growth in syngeneic C57BL/6 mice than saquinavir did. Saq-NO has been shown to block proliferation, upregulate p53 expression, and promote differentiation of C6 glioma and B16 cells. The anticancer activity of substances is frequently hampered by cancer cell chemoresistance mechanisms. Therefore, we here investigated the roles of p53 and the ATP-binding cassette (ABC) transporters P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), and breast cancer resistance protein 1 (BCRP1) in cancer cell sensitivity to saq-NO to get more information about the potential of saq-NO as anticancer drug. Saq-NO exerted anticancer effects in lower concentrations than saquinavir in a panel of human cancer cell lines. Neither p53 mutation or depletion nor expression of P-gp, MRP1, or BCRP1 affected anticancer activity of saq-NO or saquinavir. Moreover, saq-NO sensitized P-gp-, MRP1-, or BCRP1-expressing cancer cells to chemotherapy. Saq-NO induced enhanced sensitization of P-gp- or MRP1-expressing cancer cells to chemotherapy compared with saquinavir, whereas both substances similarly sensitized BCRP1-expressing cells. Washout kinetics and ABC transporter ATPase activities demonstrated that saq-NO is a substrate of P-gp as well as of MRP1. These data support the further investigation of saq-NO as an anticancer drug, especially in multidrug-resistant tumors. PMID:21170266

Expression and localization of p-glycoprotein, multidrug resistance protein 4, and breast cancer resistance protein in the female lower genital tract of human and pigtailed macaque.

Science.gov (United States)

Zhou, Tian; Hu, Minlu; Pearlman, Andrew; Patton, Dorothy; Rohan, Lisa

2014-11-01

Antiretroviral drug absorption and disposition in cervicovaginal tissue is important for the effectiveness of vaginally or orally administered drug products in preexposure prophylaxis (PrEP) of HIV-1 sexual transmission to women. Therefore, it is imperative to understand critical determinants of cervicovaginal tissue pharmacokinetics. This study aimed to examine the mRNA expression and protein localization of three efflux transporters, P-glycoprotein (P-gp), multidrug resistance-associated protein 4 (MRP4), and breast cancer resistance protein (BCRP), in the lower genital tract of premenopausal women and pigtailed macaques. Along the human lower genital tract, the three transporters were moderately to highly expressed compared to colorectal tissue and liver, as revealed by real-time reverse transcriptase polymerase chain reaction (RT-PCR). In a given genital tract segment, the transporter with the highest expression level was either BCRP or P-gp, while MRP4 was always expressed at the lowest level among the three transporters tested. The immunohistochemical staining showed that P-gp and MRP4 were localized in multiple cell types including epithelial cells and vascular endothelial cells. BCRP was predominantly localized in the vascular endothelial cells. Differences in transporter mRNA level and localization were observed among endocervix, ectocervix, and vagina. Compared to human tissues, the macaque cervicovaginal tissues displayed comparable expression and localization patterns of the three transporters, although subtle differences were observed between the two species. The role of these cervicovaginal transporters in drug absorption and disposition warrants further studies. The resemblance between human and pigtailed macaque in transporter expression and localization suggests the utility of the macaque model in the studies of human cervicovaginal transporters.

Multidrug transporters from bacteria to man : similarities in structure and function

NARCIS (Netherlands)

van Veen, HW; Konings, WN

Organisms ranging from bacteria to man possess transmembrane transporters which confer resistance to toxic corn pounds. Underlining their biological significance, prokaryotic and eukaryotic multidrug transport proteins are very similar in structure and function. Therefore, a study of the factors

Pattern of intensive phase treatment outcomes of multi-drug resistant ...

African Journals Online (AJOL)

Pattern of intensive phase treatment outcomes of multi-drug resistant tuberculosis in University of Port Harcourt Treatment Centre: a review of records from ... Data on patients' age, sex, HIV status, treatment outcomes were extracted from the hospital book records into a computer data sheet at the UPTH treatment centre.

bmr3, a third multidrug transporter gene of Bacillus subtilis.

OpenAIRE

Ohki, R; Murata, M

1997-01-01

A third multidrug transporter gene named bmr3 was cloned from Bacillus subtilis. Although Bmr3 shows relatively low homology to Bmr and Blt, the substrate specificities of these three transporters overlap. Northern hybridization analysis showed that expression of the bmr3 gene was dependent on the growth phase.

Modulation of P-glycoprotein-mediated multidrug resistance in K562 leukemic cells by indole-3-carbinol

International Nuclear Information System (INIS)

Arora, Annu; Seth, Kavita; Kalra, Neetu; Shukla, Yogeshwer

2005-01-01

Resistance to chemotherapeutic drugs is one of the major problems in the treatment of cancer. P-glycoprotein (P-gp) encoded by the mdr gene is a highly conserved protein, acts as a multidrug transporter, and has a major role in multiple drug resistance (MDR). Targeting of P-gp by naturally occurring compounds is an effective strategy to overcome MDR. Indole-3-carbinol (I3C), a glucosinolates present in cruciferous vegetables, is a promising chemopreventive agent as it is reported to possess antimutagenic, antitumorigenic, and antiestrogenic properties in experimental studies. In the present investigation, the potential of I3C to modulate P-gp expression was evaluated in vinblastine (VBL)-resistant K562 human leukemic cells. The resistant K562 cells (K562/R10) were found to be cross-resistant to vincristine (VCR), doxorubicin (DXR), and other antineoplastic agents. I3C at a nontoxic dose (10 x 10 -3 M) enhanced the cytotoxic effects of VBL time dependently in VBL-resistant human leukemia (K562/R10) cells but had no effect on parent-sensitive cells (K562/S). The Western blot analysis of K 562/R 10 cells showed that I3C downregulates the induced levels of P-gp in resistant cells near to normal levels. The quantitation of immunocytochemically stained K562/R10 cells showed 24%, 48%, and 80% decrease in the levels of P-gp by I3C for 24, 48, and 72 h of incubation. The above features thus indicate that I3C could be used as a novel modulator of P-gp-mediated multidrug resistance in vitro and may be effective as a dietary adjuvant in the treatment of MDR cancers

Amikacin Concentrations Predictive of Ototoxicity in Multidrug-Resistant Tuberculosis Patients.

Science.gov (United States)

Modongo, Chawangwa; Pasipanodya, Jotam G; Zetola, Nicola M; Williams, Scott M; Sirugo, Giorgio; Gumbo, Tawanda

2015-10-01

Aminoglycosides, such as amikacin, are used to treat multidrug-resistant tuberculosis. However, ototoxicity is a common problem and is monitored using peak and trough amikacin concentrations based on World Health Organization recommendations. Our objective was to identify clinical factors predictive of ototoxicity using an agnostic machine learning method. We used classification and regression tree (CART) analyses to identify clinical factors, including amikacin concentration thresholds that predicted audiometry-confirmed ototoxicity among 28 multidrug-resistant pulmonary tuberculosis patients in Botswana. Amikacin concentrations were measured for all patients. The quantitative relationship between predictive factors and the probability of ototoxicity were then identified using probit analyses. The primary predictors of ototoxicity on CART analyses were cumulative days of therapy, followed by cumulative area under the concentration-time curve (AUC), which improved on the primary predictor by 87%. The area under the receiver operating curve was 0.97 on the test set. Peak and trough were not predictors in any tree. When algorithms were forced to pick peak and trough as primary predictors, the area under the receiver operating curve fell to 0.46. Probit analysis revealed that the probability of ototoxicity increased sharply starting after 6 months of therapy to near maximum at 9 months. A 10% probability of ototoxicity occurred with a threshold cumulative AUC of 87,232 days · mg · h/liter, while that of 20% occurred at 120,000 days · mg · h/liter. Thus, cumulative amikacin AUC and duration of therapy, and not peak and trough concentrations, should be used as the primary decision-making parameters to minimize the likelihood of ototoxicity in multidrug-resistant tuberculosis. Copyright © 2015, Modongo et al.

Functional imaging of the multidrug resistance in vivo

International Nuclear Information System (INIS)

Lee, Jae Tae

2001-01-01

Although diverse mechanisms are involved in multidrug resistance for chemotherapeutic drugs, the development of cellular P-glycoprotein(Pgp) and multidrug-resistance associated protein (MRP) are improtant factors in the chemotherapy failure to cancer. Various detection assays provide information about the presence of drug efflux pumps at the mRNA and protein levels. However these methods do not yield information about dynamic function of Pgp and MRP in vivo. Single photon emission tomograpy (SPECT) and positron emission tomograpy (PET) are available for the detection of Pgp and MRP-mediated transport. 99m Tc-sestaMIBI and other 99m Tc-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies of tumor imaging, and to visualize blockade of Pgp-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with 11 C have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and N- (11 C]acetyl-leukotriene E4 provides an opportunity to study MRP function non-invasively in vivo. Results obtained from recent publications are reviewed to confirm the feasibility of using SPECT and PET to study the functionality of MDR transportes in vivo

Understanding institutional stakeholders’ perspectives on multidrug-resistant bacterial organism at the end of life: a qualitative study

Directory of Open Access Journals (Sweden)

Heckel M

2017-10-01

Full Text Available Maria Heckel,1 Franziska A Herbst,2 Thomas Adelhardt,3 Johanna M Tiedtke,4 Alexander Sturm,5 Stephanie Stiel,2 Christoph Ostgathe1 1Department of Palliative Medicine, Comprehensive Cancer Center Erlangen-EMN, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU, Universitätsklinikum Erlangen, Bavaria, Germany; 2Institute for General Practice, Hannover Medical School, Hannover, Germany; 3Division of Health Management, School of Business and Economics, Institute of Management (IFM, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU, Bavaria, Germany; 4Institute of Psychogerontology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU, Bavaria, Germany; 5Department of General Internal and Geriatric Medicine, Institute for Biomedicine of Aging, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU, Hospital of the Order of St John of God Regensburg, Bavaria, Germany Background: Information lacks about institutional stakeholders’ perspectives on management approaches of multidrug-resistant bacterial organism in end-of-life situations. The term “institutional stakeholder” includes persons in leading positions with responsibility in hospitals’ multidrug-resistant bacterial organism management. They have great influence on how strategies on multidrug-resistant bacterial organism management approaches in institutions of the public health system are designed. This study targeted institutional stakeholders’ individual perspectives on multidrug-resistant bacterial organism colonization or infection and isolation measures at the end of life. Methods: Between March and December 2014, institutional stakeholders of two study centers, a German palliative care unit and a geriatric ward, were queried in semistructured interviews. Interviews were audiotaped, transcribed verbatim, and analyzed qualitatively with the aid of the software MAXQDA for qualitative data analysis using principles of Grounded Theory. In addition, two external

Hepatitis B virus X protein accelerates the development of hepatoma

International Nuclear Information System (INIS)

Zhang, Xiao-Dong; Wang, Yuan; Ye, Li-Hong

2014-01-01

The chronic infection of hepatitis B virus (HBV) is closely related to the occurrence and development of hepatocellular carcinoma (HCC). Accumulated evidence has shown that HBV X protein (HBx protein) is a multifunctional regulator with a crucial role in hepatocarcinogenesis. However, information on the mechanism by which HBV induces HCC is lacking. This review focuses on the pathological functions of HBx in HBV-induced hepatocarcinogenesis. As a transactivator, HBx can modulate nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transcription factor AP-2. Moreover, HBx can affect regulatory non-coding RNAs (ncRNAs) including microRNAs and long ncRNAs (lncRNAs), such as miRNA-205 and highly upregulated in liver cancer (HULC), respectively. HBx is also involved in epigenetic modification, including methylation and acetylation. HBx interacts with various signal-transduction pathways, such as protein kinase B/Akt, Wnt/β-catenin, signal transducer and activator of transcription, and NF-κB pathways. Moreover, HBx affects cellular fate by shifting the balance toward cell survival. HBx may lead to the loss of apoptotic functions or directly contributes to oncogenesis by achieving transforming functions, which induce hepatocarcinogenesis. Additionally, HBx can modulate apoptosis and immune response by direct or indirect interaction with host factors. We conclude that HBx hastens the development of hepatoma

Prevalence and behavior of multidrug-resistant Salmonella strains on raw whole and cut nopalitos (Opuntia ficus-indica L.) and on nopalitos salads.

Science.gov (United States)

Gómez-Aldapa, Carlos A; Gutiérrez-Alcántara, Eduardo J; Torres-Vitela, M Refugio; Rangel-Vargas, Esmeralda; Villarruel-López, Angelica; Castro-Rosas, Javier

2017-09-01

The presence of multidrug-resistant Salmonella in vegetables is a significant public health concern. Nopalito is a cactaceous that is commonly consumed either raw or cooked in Mexico and other countries. The presence of antibiotic-resistant Salmonella strains on raw whole nopalitos (RWN, without prickles), raw nopalitos cut into squares (RNCS) and in cooked nopalitos salads (CNS) samples was determined. In addition, the behavior of multidrug-resistant Salmonella isolates on RWN, RNCS and CNS at 25° ± 2 °C and 3° ± 2 °C was investigated. One hundred samples of RWN, 100 of RNCS and 100 more of CNS were collected from public markets. Salmonella strains were isolated and identified in 30, 30 and 10% of the samples, respectively. Seventy multidrug-resistant Salmonella strains were isolated from all the nopalitos samples. Multidrug-resistant Salmonella isolates survived at least 15 days on RWN at 25° ± 2 °C or 3° ± 2 °C. Multidrug-resistant Salmonella isolates grew in the RNCS and CNS samples at 25° ± 2 °C. However, at 3° ± 2 °C the bacterial growth was inhibited. This is the first report about multidrug-resistant Salmonella isolation from raw nopalitos and nopalitos salads. Nopalitos from markets are very likely to be an important factor contributing to the endemicity of multidrug-resistant Salmonella-related gastroenteritis in Mexico. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Improved Survival and Cure Rates With Concurrent Treatment for Multidrug-Resistant Tuberculosis-Human Immunodeficiency Virus Coinfection in South Africa.

Science.gov (United States)

Brust, James C M; Shah, N Sarita; Mlisana, Koleka; Moodley, Pravi; Allana, Salim; Campbell, Angela; Johnson, Brent A; Master, Iqbal; Mthiyane, Thuli; Lachman, Simlatha; Larkan, Lee-Megan; Ning, Yuming; Malik, Amyn; Smith, Jonathan P; Gandhi, Neel R

2018-04-03

Mortality in multidrug-resistant (MDR) tuberculosis-human immunodeficiency virus (HIV) coinfection has historically been high, but most studies predated the availability of antiretroviral therapy (ART). We prospectively compared survival and treatment outcomes in MDR tuberculosis-HIV-coinfected patients on ART to those in patients with MDR tuberculosis alone. This observational study enrolled culture-confirmed MDR tuberculosis patients with and without HIV in South Africa between 2011 and 2013. Participants received standardized MDR tuberculosis and HIV regimens and were followed monthly for treatment response, adverse events, and adherence. The primary outcome was survival. Among 206 participants, 150 were HIV infected, 131 (64%) were female, and the median age was 33 years (interquartile range [IQR], 26-41). Of the 191 participants with a final MDR tuberculosis outcome, 130 (73%) were cured or completed treatment, which did not differ by HIV status (P = .50). After 2 years, CD4 count increased a median of 140 cells/mm3 (P = .005), and 64% had an undetectable HIV viral load. HIV-infected and HIV-uninfected participants had high rates of survival (86% and 94%, respectively; P = .34). The strongest risk factor for mortality was having a CD4 count ≤100 cells/mm3 (adjusted hazards ratio, 15.6; 95% confidence interval, 4.4-55.6). Survival and treatment outcomes among MDR tuberculosis-HIV individuals receiving concurrent ART approached those of HIV-uninfected patients. The greatest risk of death was among HIV-infected individuals with CD4 counts ≤100 cells/mm3. These findings provide critical evidence to support concurrent treatment of MDR tuberculosis and HIV.

Piperine activates human pregnane X receptor to induce the expression of cytochrome P450 3A4 and multidrug resistance protein 1

Energy Technology Data Exchange (ETDEWEB)

Wang, Yue-Ming; Lin, Wenwei; Chai, Sergio C.; Wu, Jing; Ong, Su Sien [Department of Chemical Biology and Therapeutics, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States); Schuetz, Erin G. [Department of Pharmaceutical Sciences, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States); Chen, Taosheng, E-mail: taosheng.chen@stjude.org [Department of Chemical Biology and Therapeutics, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States)

2013-10-01

Activation of the pregnane X receptor (PXR) and subsequently its target genes, including those encoding drug transporters and metabolizing enzymes, while playing substantial roles in xenobiotic detoxification, might cause undesired drug-drug interactions. Recently, an increased awareness has been given to dietary components for potential induction of diet–drug interactions through activation of PXR. Here, we studied, whether piperine (PIP), a major component extracted from the widely-used daily spice black pepper, could induce PXR-mediated expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance protein 1 (MDR1). Our results showed that PIP activated human PXR (hPXR)-mediated CYP3A4 and MDR1 expression in human hepatocytes, intestine cells, and a mouse model; PIP activated hPXR by recruiting its coactivator SRC-1 in both cellular and cell-free systems; PIP bound to the hPXR ligand binding domain in a competitive ligand binding assay in vitro. The dichotomous effects of PIP on induction of CYP3A4 and MDR1 expression observed here and inhibition of their activity reported elsewhere challenges the potential use of PIP as a bioavailability enhancer and suggests that caution should be taken in PIP consumption during drug treatment in patients, particularly those who favor daily pepper spice or rely on certain pepper remedies. - Highlights: • Piperine induces PXR-mediated CYP3A4 and MDR1 expression. • Piperine activates PXR by binding to PXR and recruiting coactivator SRC-1. • Piperine induces PXR activation in vivo. • Caution should be taken in piperine consumption during drug treatment.

Multidrug-Resistant Escherichia fergusonii: a Case of Acute Cystitis▿

Science.gov (United States)

Savini, Vincenzo; Catavitello, Chiara; Talia, Marzia; Manna, Assunta; Pompetti, Franca; Favaro, Marco; Fontana, Carla; Febbo, Fabio; Balbinot, Andrea; Di Berardino, Fabio; Di Bonaventura, Giovanni; Di Zacomo, Silvia; Esattore, Francesca; D'Antonio, Domenico

2008-01-01

We report a case in which Escherichia fergusonii, an emerging pathogen in various types of infections, was associated with cystitis in a 52-year-old woman. The offending strain was found to be multidrug resistant. Despite in vitro activity, beta-lactam treatment failed because of a lack of patient compliance with therapy. The work confirms the pathogenic potential of E. fergusonii. PMID:18256229

Add-On Therapy with Ertapenem in Infections with Multidrug Resistant Gram-Negative Bacteria: Pediatric Experience

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Sevgen Tanır Basaranoglu

2017-01-01

Full Text Available Optimal therapy for infections with carbapenem resistant GNB is not well established due to the weakness of data. Patients presenting with bloodstream infections caused by multidrug resistant Klebsiella pneumoniae were treated with a combination treatment. Optimal therapy for infections with carbapenem resistant Gram-negative bacteria is a serious problem in pediatric patients. We presented three cases who were successfully treated with addition of ertapenem to the combination treatment for bacteremia with multidrug resistant Klebsiella pneumoniae. Dual carbapenem treatment approach is a new approach for these infections and requires more data in children.

Multidrug resistance in Pseudomonas aeruginosa isolated from nosocomial respiratory and urinary infections in Aleppo, Syria.

Science.gov (United States)

Mahfoud, Maysa; Al Najjar, Mona; Hamzeh, Abdul Rezzak

2015-02-19

Pseudomonas aeruginosa represents a serious clinical challenge due to its frequent involvement in nosocomial infections and its tendency towards multidrug resistance. This study uncovered antibiotic susceptibility patterns in 177 isolates from inpatients in three key hospitals in Aleppo, the largest city in Syria. Exceptionally low susceptibility to most routinely used antibiotics was uncovered; resistance to ciprofloxacin and gentamicin was 64.9% and 70.3%, respectively. Contrarily, susceptibility to colistin was the highest (89.1%). Multidrug resistance was rife, found at a rate of 53.67% among studied P. aeruginosa isolates.

R-Flurbiprofen Traps Prostaglandins within Cells by Inhibition of Multidrug Resistance-Associated Protein-4

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Ivonne Wobst

2016-12-01

Full Text Available R-flurbiprofen is the non-COX-inhibiting enantiomer of flurbiprofen and is not converted to S-flurbiprofen in human cells. Nevertheless, it reduces extracellular prostaglandin E2 (PGE2 in cancer or immune cell cultures and human extracellular fluid. Here, we show that R-flurbiprofen acts through a dual mechanism: (i it inhibits the translocation of cPLA2α to the plasma membrane and thereby curtails the availability of arachidonic acid and (ii R-flurbiprofen traps PGE2 inside of the cells by inhibiting multidrug resistance–associated protein 4 (MRP4, ABCC4, which acts as an outward transporter for prostaglandins. Consequently, the effects of R-flurbiprofen were mimicked by RNAi-mediated knockdown of MRP4. Our data show a novel mechanism by which R-flurbiprofen reduces extracellular PGs at physiological concentrations, particularly in cancers with high levels of MRP4, but the mechanism may also contribute to its anti-inflammatory and immune-modulating properties and suggests that it reduces PGs in a site- and context-dependent manner.

The drug-binding activity of the multidrug-responding transcriptional regulator BmrR resides in its C-terminal domain.

OpenAIRE

Markham, P N; Ahmed, M; Neyfakh, A A

1996-01-01

Rhodamine and tetraphenylphosphonium, the substrates of the Bacillus subtilis multidrug efflux transporter Bmr, induce the expression of Bmr through direct interaction with its transcriptional activator BmrR. Here we show that the C-terminal domain of BmrR, expressed individually, binds both these compounds and therefore can be used as a model for molecular analysis of the phenomenon of multidrug recognition.

Isolation and characterization of DNA-dependent ATPases from the Novikoff Hepatoma

International Nuclear Information System (INIS)

Thomas, D.C.

1984-01-01

Four DNA-dependent ATPases have been purified to apparent homogeneity from extracts of the Novikoff Hepatoma, and named ATPases II, III, IV, and V. The physical and enzymological properties of ATPases II, III, and V are nearly identical, and from tryptic peptide mapping these proteins were determined to be related, though they are still chromatographically distinct; all appear to be dimers. ATPaseIV is unique among the ATPases, and is probably a monomer. ATPase V appears much more stable to thermal inactivation than the similar curves generated by ATPases II, and III. ATPase IV, however, projects of a heat-inactivation curve intermediate to these two types. ATPase II is labelled to a much higher degree than the others when treated with a heterologous protein kinase using gamma-[ 32 P]-ATP. When ATPase II was treated with this kinase, and subsequently run over a DNA-cellulose column, the profile of ATPase II was found to contain small peaks of activity in the positions where ATPases III and V normally elute, suggesting that ATPase II may be a dephosphorylated form of the other two. The ATPases have been extensively characterized with respect to reaction products and requirements, substrate utilization, DNA effector requirements, and effects of ATP analogs

Study of multidrug resistance and radioresistance

International Nuclear Information System (INIS)

Kang, Yoon Koo; Yoo, Young Do

1999-04-01

We investigated the mechanism of 5-FU, adriamycin, radiation resistance in Korean gastric cancer cells. First we investigated the relation between Rb and multidrug resistance. Rb stable transfectants exhibited 5- to 10- fold more resistance to adriamycin than the control cells. These Rb transfectants showed increased MDR1 expression. We also investigated up-regulation in radiation-resistant tumor tissues. HSP27, MRP-8, GST, and NKEF-B were up-regulated in radiation resistant tumor. Expression of NKEF-B was also increased by radiation exposure in Head and Neck cells. These results demonstrated that NKEF-B is a stress response protein and it may have an important role in radiation resistance

Involvement of c-Met- and phosphatidylinositol 3-kinase dependent pathways in arsenite-induced downregulation of catalase in hepatoma cells.

Science.gov (United States)

Kim, Soohee; Lee, Seung Heon; Kang, Sukmo; Lee, Lyon; Park, Jung-Duck; Ryu, Doug-Young

2011-01-01

Catalase protects cells from reactive oxygen species-induced damage by catalyzing the breakdown of hydrogen peroxide to oxygen and water. Arsenite decreases catalase activity; it activates phosphatidylinositol 3-kinase (PI3K) and its key downstream effector Akt in a variety of cells. The PI3K pathway is known to inhibit catalase expression. c-Met, an upstream regulator of PI3K and Akt, is also involved in the regulation of catalase expression. To examine the involvement of c-Met and PI3K pathways in the arsenite-induced downregulation of catalase, catalase mRNA and protein expression were analyzed in the human hepatoma cell line HepG2 treated with arsenite and either an inhibitor of c-Met (PHA665752 (PHA)) or of PI3K (LY294002 (LY)). Arsenite treatment markedly activated Akt and decreased the levels of both catalase mRNA and protein. Both PHA and LY attenuated arsenite-induced activation of Akt. PHA and LY treatment also prevented the inhibitory effect of arsenite on catalase protein expression but did not affect the level of catalase mRNA. These findings suggest that arsenite-induced inhibition of catalase expression is regulated at the mRNA and post-transcriptional levels in HepG2 cells, and that the post-transcriptional regulation is mediated via c-Met- and PI3K-dependent mechanisms.

Comparison of the effects of Mylabris and Acanthopanax senticosus on promising cancer marker polyamines in plasma of a Hepatoma-22 mouse model using HPLC-ESI-MS.

Science.gov (United States)

Wang, Qian; Wang, Yixiang; Liu, Ran; Yan, Xu; Li, Yujiao; Fu, Hui; Bi, Kaishun; Li, Qing

2013-02-01

A simple and sensitive method for the simultaneous determination of plasma concentrations of five polyamines in normal and Hepatoma-22 mice, and mice treated with Mylabris and Acanthopanax senticosus was developed by HPLC-ESI-MS. Male Kunming mice were divided into nine groups, a control group (inoculation without treatment), a positive group (Cyclophosphamide), treatment groups [Mylabris (4, 8, 16 mg/kg), Acanthopanax senticosus (6, 12, 24 g/kg)] and a normal group (without inoculation). Twenty-four hours after the last administration, plasma samples were collected. The derived polyamines were separated on a C(18) column by a gradient elution using methanol-water with excellent linearity within the range from 2.5 to 1000 ng/mL. Polyamines were confirmed as useful biochemical markers of hepatoma. The differences in anti-cancer therapeutic efficacy between Mylabris and Acanthopanax senticosus might contribute to the variability of polyamine levels in vivo. This HPLC-ESI-MS method was successfully applied to investigate the relationship between polyamines and cancer in mice and might be a useful method to test the activity of potential anti-tumor drugs. Copyright © 2012 John Wiley & Sons, Ltd.

Multidrug resistance among new tuberculosis cases: detecting local variation through lot quality-assurance sampling.

Science.gov (United States)

Hedt, Bethany Lynn; van Leth, Frank; Zignol, Matteo; Cobelens, Frank; van Gemert, Wayne; Nhung, Nguyen Viet; Lyepshina, Svitlana; Egwaga, Saidi; Cohen, Ted

2012-03-01

Current methodology for multidrug-resistant tuberculosis (MDR TB) surveys endorsed by the World Health Organization provides estimates of MDR TB prevalence among new cases at the national level. On the aggregate, local variation in the burden of MDR TB may be masked. This paper investigates the utility of applying lot quality-assurance sampling to identify geographic heterogeneity in the proportion of new cases with multidrug resistance. We simulated the performance of lot quality-assurance sampling by applying these classification-based approaches to data collected in the most recent TB drug-resistance surveys in Ukraine, Vietnam, and Tanzania. We explored 3 classification systems- two-way static, three-way static, and three-way truncated sequential sampling-at 2 sets of thresholds: low MDR TB = 2%, high MDR TB = 10%, and low MDR TB = 5%, high MDR TB = 20%. The lot quality-assurance sampling systems identified local variability in the prevalence of multidrug resistance in both high-resistance (Ukraine) and low-resistance settings (Vietnam). In Tanzania, prevalence was uniformly low, and the lot quality-assurance sampling approach did not reveal variability. The three-way classification systems provide additional information, but sample sizes may not be obtainable in some settings. New rapid drug-sensitivity testing methods may allow truncated sequential sampling designs and early stopping within static designs, producing even greater efficiency gains. Lot quality-assurance sampling study designs may offer an efficient approach for collecting critical information on local variability in the burden of multidrug-resistant TB. Before this methodology is adopted, programs must determine appropriate classification thresholds, the most useful classification system, and appropriate weighting if unbiased national estimates are also desired.

ANTIMICROBIAL ACTIVITY OF PINEAPPLE (ANANAS COMOSUS L. MERR EXTRACT AGAINST MULTIDRUG-RESISTANT OF PSEUDOMONAS AERUGINOSA: AN IN VITRO STUDY

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Rahmat Sayyid Zharfan

2017-08-01

Full Text Available Pseudomonas aeruginosa is the main cause of nosocomial infection which is responsible for 10% of hospital-acquired infection. Pseudomonas aeruginosa tends to mutate and displays potential for development of antibiotic resistance. Approximately, 10% of global bacterial isolates are found as Multidrug-resistant Pseudomonas aeruginosa. Pseudomonas aeruginosa have a quite tremendous severity index, especially on pneumonia and urinary tract infections, even sepsis, which 50% mortality rate. Pineapple (Ananas comosus L. Merr has antimicrobial properties. The active antimicrobial compounds in Ananas comosus L. Merr include saponin and bromelain. This research aims to find the potency of antimicrobial effect of pineapple (Ananas comosus L. Merr extract towards Multidrug-resistant Pseudomonas aeruginosa. Multidrug-resistant Pseudomonas aeruginosa specimen is obtained from patient’s pus in orthopaedic department, Dr Soetomo Public Hospital, Surabaya. Multidrug-resistant Pseudomonas aeruginosa specimen is resistant to all antibiotic agents except cefoperazone-sulbactam. This research is conducted by measuring the Minimum Inhibitory Concentration (MIC through dilution test with Mueller-Hinton broth medium. Pineapple extract (Ananas comosus L. Merr. is dissolved in aquadest, then poured into test tube at varying concentrations (6 g/ml; 3 g/ml; 1.5 g/ml; 0.75 g/ml, 0.375 g/ml; and 0.1875 g/ml. After 24 hours’ incubation, samples are plated onto nutrient agar plate, to determine the Minimum Bactericidal Concentration (MBC. The extract of pineapple (Ananas comosus L. Merr has antimicrobial activities against Multidrug-resistant Pseudomonas aeruginosa. Minimum Inhibitory Concentration (MIC could not be determined, because turbidity changes were not seen. The Minimum Bactericidal Concentration (MBC of pineapple extract (Ananas comosus L. Merr to Multidrug-resistant Pseudomonas aeruginosa is 0.75 g/ml. Further study of in vivo is needed.

Excision of foreign gene product with cathepsin D in chicken hepatoma cell line

International Nuclear Information System (INIS)

Sato, Masaharu; Kawashima, Tsuyoshi; Aosasa, Masayoshi; Horiuchi, Hiroyuki; Furusawa, Shuichi; Matsuda, Haruo

2005-01-01

To easily and rapidly recover exogenous gene products from chicken egg yolk, we constructed pVTG-catD (VTG, vitellogenin; catD, cathepsin D), a vector cassette carrying two catD-recognition signal peptides (catD-RSPs) in addition to the cloning site. An enhanced green fluorescence protein (EGFP)-encoding DNA fragment was ligated into the pVTG-catD. When the resultant construct pVTG-EGFP-catD containing histidine- and myc-tags was transfected into the chicken hepatoma cell line LMH, EGFP-expression at 24 h post-cultivation was confirmed by fluorescence microscopy. Because a signal peptide (NTVLAEF) encoded in pVTG-EGFP-catD is recognized by catD, the VTG-EGFP fusion protein digested with catD was detectable by Western blotting. Digested exogenous gene product was recovered with nickel resin. These results indicate that catD-recognition sites bearing pVTG-catD and His-tags are functional in chicken LMH cells. Therefore, the system described here may be of use in making excision exogenous gene products in the chicken and in creating homozygous knock-in chickens

Isolation and establishment of radiotolerant hepatoma cell subline

International Nuclear Information System (INIS)

Jin Wensen; Kong Zhaolu; Zhang Jianghong; Shen Zhifen; Tong Shungao; Ji Huajun; Jin Yizun

2009-01-01

Objective: To induce and isolate the monoclonal cell subline, in order to establish the experimental model for further investigating biologic characteristics in radiotolerant hepatoma cells. Methods: HepG2 cells were irradiated by γ-rays at the dose of 2 Gy each time with the total absorbed dose of 60 Gy. After monoclonal cell being selected and extensively cultured, the cell subline was named as HepG2/R60. Furthermore, HepG2/R60 cells were identified by observing the changes of morphology, ultrastructure, growth characteristics and radiosensitivity. The levels of radioresistant correlative gene mRNA in HepG2/R60 cells after exposure to 2 Gy irradiation, were also detected by RT-PCR, and then compared with parental HepG2 cells. Results: HepG2/R60 cell subline was successfully established by fractionated irradiation at 2 Gy. HepG2/R60 cells displayed higher irregularity, the clearer appearance and dissociation of cell junctions compared with parental HepG2 cells. Ultrastnictural investigations through transmission electron microscopy (TEM) showed that there was an increase of microvillus on the surfaces of HepG2/R60 cells with plenty of rough endo-plasmic reticulum, abundance of mitochondria and viable Golgi complex. Further observation found that the growth of HepG2/R60 cells was slower and its population doubling time (PDT) prolonged arrived at 34.9 h. Moreover, the radiosensitivity of HepG2/R60 cells was lower than that of parental HepG2 cells. Additionally, the levels of radioresistance correlative genes were increased in HepG2/R60 cells by 2 Gy irradiaiton Conclusions: Radiotolerant cell subline - HepG2/R60 was successfully isolated and established by fractionated irradiation. (authors)

pH-Dependent doxorubicin release from terpolymer of starch, polymethacrylic acid and polysorbate 80 nanoparticles for overcoming multi-drug resistance in human breast cancer cells.

Science.gov (United States)

Shalviri, Alireza; Raval, Gaurav; Prasad, Preethy; Chan, Carol; Liu, Qiang; Heerklotz, Heiko; Rauth, Andrew Michael; Wu, Xiao Yu

2012-11-01

This work investigated the capability of a new nanoparticulate system, based on terpolymer of starch, polymethacrylic acid and polysorbate 80, to load and release doxorubicin (Dox) as a function of pH and to evaluate the anticancer activity of Dox-loaded nanoparticles (Dox-NPs) to overcome multidrug resistance (MDR) in human breast cancer cells in vitro. The Dox-NPs were characterized by Fourier transform infrared spectroscopy (FTIR), isothermal titration calorimetry (ITC), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The cellular uptake and cytotoxicity of the Dox-loaded nanoparticles were investigated using fluorescence microscopy, flow cytometry, and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay. The nanoparticles were able to load up to 49.7±0.3% of Dox with a high loading efficiency of 99.9±0.1%, while maintaining good colloidal stability. The nanoparticles released Dox at a higher rate at acidic pH attributable to weaker Dox-polymer molecular interactions evidenced by ITC. The Dox-NPs were taken up by the cancer cells in vitro and significantly enhanced the cytotoxicity of Dox against human MDR1 cells with up to a 20-fold decrease in the IC50 values. The results suggest that the new terpolymeric nanoparticles are a promising vehicle for the controlled delivery of Dox for treatment of drug resistant breast cancer. Copyright © 2012 Elsevier B.V. All rights reserved.

Draft Genome Sequences of Six Multidrug-Resistant Clinical Strains of Acinetobacter baumannii, Isolated at Two Major Hospitals in Kuwait.

Science.gov (United States)

Nasser, Kother; Mustafa, Abu Salim; Khan, Mohd Wasif; Purohit, Prashant; Al-Obaid, Inaam; Dhar, Rita; Al-Fouzan, Wadha

2018-04-19

Acinetobacter baumannii is an important opportunistic pathogen in global health care settings. Its dissemination and multidrug resistance pose an issue with treatment and outbreak control. Here, we present draft genome assemblies of six multidrug-resistant clinical strains of A. baumannii isolated from patients admitted to one of two major hospitals in Kuwait. Copyright © 2018 Nasser et al.

Technetium-99m-hexakis-2-methoxyisobutylisonitrile scintigraphy and multidrug resistance-related protein expression in human primary lung cancer

International Nuclear Information System (INIS)

Duan Xiaoyi; Wang Jiansheng; Liu Min; Guo Youmin

2008-01-01

The occurrence of multidrug resistance (MDR) is a major cause of resistance to chemotherapeutic agents in patients with lung cancer, in part owing to the overexpression of MDR-related proteins. Technetium-99m-hexakis-2-methoxyisobutylisonitrile ( 99m Tc-MIBI) has been shown to be a substrate for some MDR-related proteins. The aim of this study is to evaluate the role of 99m Tc-MIBI scintigraphy for functional imaging of MDR-related protein phenotypes. To determine the correlation between 99m Tc-MIBI scintigraphy and the expression level of P-glycoprotein (Pgp), multidrug-resistance protein (MRP), and glutathione-S-transferase Pi (GSTπ), 26 patients (17 men and 9 women, median age 57.5 years) with primary lung cancer were investigated. Following intravenous administration of 925 MBq 99m Tc-MIBI, single-photon emission computed tomography (SPECT) and computed tomography (CT) were performed at 15 min and 2 h. On the basis of the fused images, tumor to background (T/B) ratio of both early and delayed images, and washout rate (WR%) of 99m Tc-MIBI were calculated. The immunohistochemical staining of Pgp, MRP, and GSTπ was performed, and the expression level was semiquantitated using a pathoimage analysis system. The imaging results were compared with the status of Pgp, MRP, and GSTπ expression. The WR% of 99m Tc-MIBI showed a significant positive correlation with Pgp expression (r=0.560, P=0.003), as no correlation was observed between WR% and MRP or GSTπ (r=0.354, P=0.076; r=0.324, P=0.106). Neither early T/B nor delayed T/B correlated with the expression level of Pgp, MRP, and GSTπ. WR%, Pgp, and GSTπ expression showed significant differences between squamous cell carcinoma (group A) and adenocarcinoma (group B). There was no significant difference among Pgp, MRP, and GSTπ expression levels in any cases (P>0.05). Our data confirmed that 99m Tc-MIBI scintigraphy is useful for determining the MDR caused by Pgp in patients with primary lung cancer. (author)

The secondary resistome of multidrug-resistant Klebsiella pneumoniae.

Science.gov (United States)

Jana, Bimal; Cain, Amy K; Doerrler, William T; Boinett, Christine J; Fookes, Maria C; Parkhill, Julian; Guardabassi, Luca

2017-02-15

Klebsiella pneumoniae causes severe lung and bloodstream infections that are difficult to treat due to multidrug resistance. We hypothesized that antimicrobial resistance can be reversed by targeting chromosomal non-essential genes that are not responsible for acquired resistance but essential for resistant bacteria under therapeutic concentrations of antimicrobials. Conditional essentiality of individual genes to antimicrobial resistance was evaluated in an epidemic multidrug-resistant clone of K. pneumoniae (ST258). We constructed a high-density transposon mutant library of >430,000 unique Tn5 insertions and measured mutant depletion upon exposure to three clinically relevant antimicrobials (colistin, imipenem or ciprofloxacin) by Transposon Directed Insertion-site Sequencing (TraDIS). Using this high-throughput approach, we defined three sets of chromosomal non-essential genes essential for growth during exposure to colistin (n = 35), imipenem (n = 1) or ciprofloxacin (n = 1) in addition to known resistance determinants, collectively termed the "secondary resistome". As proof of principle, we demonstrated that inactivation of a non-essential gene not previously found linked to colistin resistance (dedA) restored colistin susceptibility by reducing the minimum inhibitory concentration from 8 to 0.5 μg/ml, 4-fold below the susceptibility breakpoint (S ≤ 2 μg/ml). This finding suggests that the secondary resistome is a potential target for developing antimicrobial "helper" drugs that restore the efficacy of existing antimicrobials.

New-Onset Psychosis in a Multi-Drug Resistant Tuberculosis Patient ...

African Journals Online (AJOL)

Drug-resistant tuberculosis poses a serious challenge to global control of TB. These forms of TB do not respond to the standard six-month treatment; it can take two years or more to treat with category IV drugs that are less potent, more toxic and much more expensive. Treatment of multi-drug resistant tuberculosis is still ...

Multidrug resistant shigella flexneri infection simulating intestinal intussusception

Directory of Open Access Journals (Sweden)

Srirangaraj Sreenivasan

2016-01-01

Full Text Available Shigella enteritis remains an important cause of mortality and morbidity in all age groups, in developing as well as developed countries. Owing to the emerging resistance to multiple antibiotics among Shigella spp., it has been recognized as a major global public health concern and warrants constant monitoring of its resistance pattern. We report a case of segmental ileitis caused by non.-ESBL producing multidrug resistant Shigella flexneri in an infant clinically mimicking intussusception, which was effectively treated by ceftriaxone.

Repurposing ebselen for treatment of multidrug-resistant staphylococcal infections

OpenAIRE

Shankar Thangamani; Waleed Younis; Mohamed N. Seleem

2015-01-01

Novel antimicrobials and new approaches to developing them are urgently needed. Repurposing already-approved drugs with well-characterized toxicology and pharmacology is a novel way to reduce the time, cost, and risk associated with antibiotic innovation. Ebselen, an organoselenium compound, is known to be clinically safe and has a well-known pharmacology profile. It has shown potent bactericidal activity against multidrug-resistant clinical isolates of staphylococcus aureus, including methic...

Influence of multidrug resistance on 18F-FCH cellular uptake in a glioblastoma model

International Nuclear Information System (INIS)

Vanpouille, Claire; Jeune, Nathalie le; Clotagatide, Anthony; Dubois, Francis; Kryza, David; Janier, Marc; Perek, Nathalie

2009-01-01

Multidrug resistance, aggressiveness and accelerated choline metabolism are hallmarks of malignancy and have motivated the development of new PET tracers like 18 F-FCH, an analogue of choline. Our aim was to study the relationship of multidrug resistance of cultured glioma cell lines and 18 F-FCH tracer uptake. We used an in vitro multidrug-resistant (MDR) glioma model composed of sensitive parental U87MG and derived resistant cells U87MG-CIS and U87MG-DOX. Aggressiveness, choline metabolism and transport were studied, particularly the expression of choline kinase (CK) and high-affinity choline transporter (CHT1). FCH transport studies were assessed in our glioblastoma model. As expected, the resistant cell lines express P-glycoprotein (Pgp), multidrug resistance-associated protein isoform 1 (MRP1) and elevated glutathione (GSH) content and are also more mobile and more invasive than the sensitive U87MG cells. Our results show an overexpression of CK and CHT1 in the resistant cell lines compared to the sensitive cell lines. We found an increased uptake of FCH (in % of uptake per 200,000 cells) in the resistant cells compared to the sensitive ones (U87MG: 0.89±0.14; U87MG-CIS: 1.27±0.18; U87MG-DOX: 1.33±0.13) in line with accelerated choline metabolism and aggressive phenotype. FCH uptake is not influenced by the two ATP-dependant efflux pumps: Pgp and MRP1. FCH would be an interesting probe for glioma imaging which would not be effluxed from the resistant cells by the classic MDR ABC transporters. Our results clearly show that FCH uptake reflects accelerated choline metabolism and is related to tumour aggressiveness and drug resistance. (orig.)

Degradation of surface-labeled hepatoma membrane polypeptides: effect of inhibitors

International Nuclear Information System (INIS)

Hare, J.F.; Huston, M.

1984-01-01

When their membrane proteins were labeled with 125I by lactoperoxidase, dividing hepatoma cells lost radioactivity to the medium in a biphasic manner (T1/2 . 16-26 h, greater than 40 h). Lysosomotropic weak bases, chloroquine, and NH4Cl inhibited the rapid phase by 59%. More than 50% of the radioactivity which accumulates in the media from dividing cells during the first 4 h after labeling was trichloroacetic acid-soluble, and was identified as iodotyrosine. Iodotyrosine release from labeled membrane proteins was 60-71% inhibited by lysosomotropic agents chloroquine and NH4Cl as well as the sodium-proton ionophore, monensin. The inhibitory effect of NH4Cl and monensin was reversible. Inhibitors of microtubule and microfilament function and transglutamination had no effect on release of iodotyrosine to the medium, but trypsin-like protease inhibitors, p-aminobenzamidine, tosyl-L-lysine/chloromethylketone, and phenylmethylsulfonyl fluoride, as well as the cathepsin B inhibitor, leupeptin, inhibited by 21-24%. Iodotyrosine release showed a biphasic Arrhenius plot with an activation energy of 17 kcal/mol above but 27 kcal/mol below 20 degrees C. These results indicate that cell membrane polypeptides require a temperature-limiting event as well as passage through an ion-sensitive compartment prior to their complete degradation to constituent amino acids. In contrast to other lysosomal-mediated events, however, iodinated membrane proteins of dividing cells are degraded in a manner insensitive to agents which disrupt the cytoskeleton

Carbapenem Susceptibility and Multidrug-Resistance in Pseudomonas aeruginosa Isolates in Egypt.

Science.gov (United States)

Hashem, Hany; Hanora, Amro; Abdalla, Salah; Shawky, Alaa; Saad, Alaa

2016-11-01

Resistant Pseudomonas aeruginosa is a serious concern for antimicrobial therapy, as the common isolates exhibit variable grades of resistance, involving beta-lactamase enzymes, beside native defense mechanisms. The present study was designed to determine the occurrence of Metallo-β- Lactamases (MBL) and Amp C harboring P. aeruginosa isolates from Suez Canal university hospital in Ismailia, Egypt. A total of 147 P. aeruginosa isolates, recovered from 311 patients during a 10-month period, were collected between May 2013 and February 2014; the isolates were collected from urine, wound and sputum. Minimum inhibitory concentration (MIC) determined by agar dilution methods was ≥2 μg/mL for meropenem and imipenem. Identification of P. aeruginosa was confirmed using API 20NE. Metallo-β- Lactamases and Amp C were detected based on different phenotypic methods. Overall, 26.5% of P. aeruginosa isolates (39/147) were carbapenem resistant isolates. Furthermore, 64.1% (25/39) were MBL producers, these isolates were screened by the combined disc and disc diffusion methods to determine the ability of MBL production. Both MBL and Amp C harbored P. aeruginosa isolates were 28% (7/25). Sixty-four percent of P. aeruginosa isolates were multidrug resistant (MDR) (16/25). The sensitivity toward polymyxin, imipenem, norfloxacin, piperacillin-tazobactam and gentamicin was 99%, 91%, 88%, 82% and 78%, respectively. The resistance rate towards cefotaxime, ceftazidime, cefepime, aztreonam and meropenem was 98.6%, 86%, 71.4%, 34% and 30%, respectively. Multidrug resistance was significantly associated with MBL production in P. aeruginosa . Early detection of MBL-producing P. aeruginosa and hospital antibiotic policy prescription helps proper antimicrobial therapy and avoidance of dissemination of these multidrug resistance isolates.

Antimicrobial peptides as potential anti-biofilm agents against multidrug-resistant bacteria.

Science.gov (United States)

Chung, Pooi Yin; Khanum, Ramona

2017-08-01

Bacterial resistance to commonly used drugs has become a global health problem, causing increased infection cases and mortality rate. One of the main virulence determinants in many bacterial infections is biofilm formation, which significantly increases bacterial resistance to antibiotics and innate host defence. In the search to address the chronic infections caused by biofilms, antimicrobial peptides (AMP) have been considered as potential alternative agents to conventional antibiotics. Although AMPs are commonly considered as the primitive mechanism of immunity and has been extensively studied in insects and non-vertebrate organisms, there is now increasing evidence that AMPs also play a crucial role in human immunity. AMPs have exhibited broad-spectrum activity against many strains of Gram-positive and Gram-negative bacteria, including drug-resistant strains, and fungi. In addition, AMPs also showed synergy with classical antibiotics, neutralize toxins and are active in animal models. In this review, the important mechanisms of action and potential of AMPs in the eradication of biofilm formation in multidrug-resistant pathogen, with the goal of designing novel antimicrobial therapeutics, are discussed. Copyright © 2017. Published by Elsevier B.V.

The dietary flavonoid kaempferol effectively inhibits HIF-1 activity and hepatoma cancer cell viability under hypoxic conditions.

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Mylonis, Ilias; Lakka, Achillia; Tsakalof, Andreas; Simos, George

2010-07-16

Hepatocellular carcinoma (HCC) is characterized by high mortality rates and resistance to conventional treatment. HCC tumors usually develop local hypoxia, which stimulates proliferation of cancer cells and renders them resilient to chemotherapy. Adaptation of tumor cells to the hypoxic conditions depends on the hypoxia-inducible factor 1 (HIF-1). Over-expression of its regulated HIF-1alpha subunit, an important target of anti-cancer therapy, is observed in many cancers including HCC and is associated with severity of tumor growth and poor patient prognosis. In this report we investigate the effect of the dietary flavonoid kaempferol on activity, expression levels and localization of HIF-1alpha as well as viability of human hepatoma (Huh7) cancer cells. Treatment of Huh7 cells with kaempferol under hypoxic conditions (1% oxygen) effectively inhibited HIF-1 activity in a dose-dependent manner (IC(50)=5.16microM). The mechanism of this inhibition did not involve suppression of HIF-1alpha protein levels but rather its mislocalization into the cytoplasm due to inactivation of p44/42 MAPK by kaempferol (IC(50)=4.75microM). Exposure of Huh7 cells to 10microM kaempferol caused significant reduction of their viability, which was remarkably more evident under hypoxic conditions. In conclusion, kaempferol, a non-toxic natural food component, inhibits both MAPK and HIF-1 activity at physiologically relevant concentrations (5-10microM) and suppresses hepatocarcinoma cell survival more efficiently under hypoxia. It has, therefore, potential as a therapeutic or chemopreventive anti-HCC agent. Copyright 2010 Elsevier Inc. All rights reserved.

Prevalence and multidrug resistance pattern of Salmonella isolated from resident wild birds of Bangladesh

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Abdullah Al Faruq

2016-10-01

Full Text Available Aim: Salmonellosis is one of the most common zoonotic diseases, and the presence of antimicrobial resistant Salmonella in wild birds is global public health threat. Throughout the last decades, multidrug resistance of Salmonella spp. has increased, particularly in developing countries. Therefore, a cross-sectional study was conducted to investigate the prevalence of Salmonella spp. and antimicrobial resistance pattern against Salmonella spp. from two species of resident wild birds namely house crow (Corvus splendens and Asian pied starling (Gracupica contra. Materials and Methods: Samples were collected from cloacal swabs of house crows and Asian pied starling for isolating Salmonella spp. (bacteriological culture methods followed by antimicrobial susceptibility testing (disk diffusion method against Salmonella spp. isolates during March to December 2014. Results: The prevalence of Salmonella in Asian pied starling and house crows were 67% and 65%, respectively. Within the category of samples from different species, the variation in prevalence was not varied significantly (p>0.05. Isolated Salmonella spp. was tested for resistance to six different antimicrobial agents. Among six antimicrobial tested, 100% resistance were found to penicillin, oxacillin, and clindamycin followed by erythromycin (50-93%, kanamycin (7-20%, and cephalothin (30-67% from both species of birds. Kanamycin remained sensitive in (70-73%, cephalothin (26-70%, and erythromycin appeared to be (0-30% sensitive against Salmonella spp. isolates. Isolated Salmonella spp. was multidrug resistant up to three of the six antimicrobials tested. Conclusion: It can be said that the rational use of antimicrobials needs to be adopted in the treatment of disease for livestock, poultry, and human of Bangladesh to limit the emergence of drug resistance to Salmonella spp.

Epidemiology and molecular characterization of multidrug-resistant Gram-negative bacteria in Southeast Asia

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Nuntra Suwantarat

2016-05-01

Full Text Available Abstract Background Multidrug-resistant Gram-negative bacteria (MDRGN, including extended-spectrum β-lactamases (ESBLs and multidrug-resistant glucose-nonfermenting Gram-negative bacilli (nonfermenters, have emerged and spread throughout Southeast Asia. Methods We reviewed and summarized current critical knowledge on the epidemiology and molecular characterization of MDRGN in Southeast Asia by PubMed searches for publications prior to 10 March 2016 with the term related to “MDRGN definition” combined with specific Southeast Asian country names (Thailand, Singapore, Malaysia, Vietnam, Indonesia, Philippines, Laos, Cambodia, Myanmar, Brunei. Results There were a total of 175 publications from the following countries: Thailand (77, Singapore (35, Malaysia (32, Vietnam (23, Indonesia (6, Philippines (1, Laos (1, and Brunei (1. We did not find any publications on MDRGN from Myanmar and Cambodia. We did not include publications related to Shigella spp., Salmonella spp., and Vibrio spp. and non-human related studies in our review. English language articles and abstracts were included for analysis. After the abstracts were reviewed, data on MDRGN in Southeast Asia from 54 publications were further reviewed and included in this study. Conclusions MDRGNs are a major contributor of antimicrobial-resistant bacteria in Southeast Asia. The high prevalence of ESBLs has been a major problem since 2005 and is possibly related to the development of carbapenem resistant organisms in this region due to the overuse of carbapenem therapy. Carbapenem–resistant Acinetobacter baumannii is the most common pathogen associated with nosocomial infections in this region followed by carbapenem-resistant Pseudomonas aeruginosa. Although Southeast Asia is not an endemic area for carbapenem-resistant Enterobacteriaceae (CRE, recently, the rate of CRE detection has been increasing. Limited infection control measures, lack of antimicrobial control, such as the presence of

Multidrug-resistant tuberculosis in Europe, 2010-2011

DEFF Research Database (Denmark)

Günther, Gunar; van Leth, Frank; Alexandru, Sofia

2015-01-01

Drug-resistant Mycobacterium tuberculosis is challenging elimination of tuberculosis (TB). We evaluated risk factors for TB and levels of second-line drug resistance in M. tuberculosis in patients in Europe with multidrug-resistant (MDR) TB. A total of 380 patients with MDR TB and 376 patients...... with non-MDR TB were enrolled at 23 centers in 16 countries in Europe during 2010-2011. A total of 52.4% of MDR TB patients had never been treated for TB, which suggests primary transmission of MDR M. tuberculosis. At initiation of treatment for MDR TB, 59.7% of M. tuberculosis strains tested were...

Recombinant Newcastle disease virus (NDV/Anh-IL-2 expressing human IL-2 as a potential candidate for suppresses growth of hepatoma therapy

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Yunzhou Wu

2016-09-01

Full Text Available Newcastle disease virus (NDV have shown oncolytic therapeutic efficacy in preclinical study and are currently approved for clinical trials. NDV Anhinga strain which is a mesogenic strain should be classified as lytic strain and has a therapeutic efficacy in hepatocellular cancer. In this study, we evaluated the capacity of NDV Anhinga strain to elicit immune reaction in vivo and the possibility for using as a vaccine vector for expressing tumor therapeutic factors. Interleukin-2 (IL-2 could boost the immune response against the tumor cells. Therefore, we use NDV Anhinga strain as backbone to construct a recombinant virus (NDV/Anh-IL-2 expressing IL-2. The virus growth curve showed that the production of recombinant NDV/Anh-IL-2 was slightly delayed compared to the wild type. The NDV/Anh-IL-2 strain could express soluble IL-2 and effectively inhibit the growth of hepatocellular carcinoma in vivo. 60 days post-treatment, mice which were completely cured by previous treatment were well protected when rechallenged with the same tumor cell. From the H&E-stained sections, intense infiltration of lymphocyte was observed in the NDV Anhinga strain treated group, especially in NDV/Anh-IL-2 group. The NDV Anhinga strain could not only kill the tumor directly, but could also elicit immune reaction and a potent immunological memory when killing tumor in vivo. In conclusion, the Anhinga strain could be an effective vector for tumor therapy; the recombinant NDV/Anh-IL-2 strain expressing soluble IL-2 is a promising candidate for hepatoma therapy.

Structures of BmrR-Drug Complexes Reveal a Rigid Multidrug Binding Pocket And Transcription Activation Through Tyrosine Expulsion

Energy Technology Data Exchange (ETDEWEB)

Newberry, K.J.; Huffman, J.L.; Miller, M.C.; Vazquez-Laslop, N.; Neyfakh, A.A.; Brennan, R.G.

2009-05-22

BmrR is a member of the MerR family and a multidrug binding transcription factor that up-regulates the expression of the bmr multidrug efflux transporter gene in response to myriad lipophilic cationic compounds. The structural mechanism by which BmrR binds these chemically and structurally different drugs and subsequently activates transcription is poorly understood. Here, we describe the crystal structures of BmrR bound to rhodamine 6G (R6G) or berberine (Ber) and cognate DNA. These structures reveal each drug stacks against multiple aromatic residues with their positive charges most proximal to the carboxylate group of Glu-253 and that, unlike other multidrug binding pockets, that of BmrR is rigid. Substitution of Glu-253 with either alanine (E253A) or glutamine (E253Q) results in unpredictable binding affinities for R6G, Ber, and tetraphenylphosphonium. Moreover, these drug binding studies reveal that the negative charge of Glu-253 is not important for high affinity binding to Ber and tetraphenylphosphonium but plays a more significant, but unpredictable, role in R6G binding. In vitro transcription data show that E253A and E253Q are constitutively active, and structures of the drug-free E253A-DNA and E253Q-DNA complexes support a transcription activation mechanism requiring the expulsion of Tyr-152 from the multidrug binding pocket. In sum, these data delineate the mechanism by which BmrR binds lipophilic, monovalent cationic compounds and suggest the importance of the redundant negative electrostatic nature of this rigid drug binding pocket that can be used to discriminate against molecules that are not substrates of the Bmr multidrug efflux pump.

Growth characteristics and imaging properties of the morris hepatoma 3924a in ACI rats: A suitable model for transarterial chemoembolization

International Nuclear Information System (INIS)

Truebenbach, Jochen; Graepler, Florian; Pereira, Philippe L; Ruck, Peter; Lauer, Ulrich; Gregor, Michael; Claussen, Claus-D.; Huppert, Peter E.

2000-01-01

Purpose: For experimental studies investigating modalities and efficacy of transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) an animal model resembling the human situation as closely as possible would be appropriate. Specifically, reproducible tumor growth characteristics with the capability for appropriate in vivo imaging to monitor treatment efficacy are required.Methods: Morris hepatoma 3924A was implanted into the liver of 30 ACI rats. Tumor growth was followed by angiography (n=10), ultrasound (US, n=30), native computed tomography (CT. n=16), and native magnetic resonance imaging (MRU n=30) between day 8 and day 36 after implantation. The radiological morphological characteristics were compared with the macroscopic and microscopic histological findings of the explanted tumors.Results: In all 30 animals a solitary liver tumor was found and macroscopically no signs of metastases, ascites, or peritoneal tumor were visible. On histopathological examination tumor sizes ranged between 27 ± 3 mm 3 (day 8) and 3468 ± 79 mm 3 (day 36). The first signs of tumor necrosis occurred at day 16. US allowed tumor visualization from day 8, MRI from day 8, angiography from day 10, and CT from day 14.Conclusions: The tumor model has the potential to be used for the visualization of tumor growth by MRI and US. The potential for monitoring therapeutic effects of TACE needs to be investigated.

Effects of currently used pesticides in the AhR-CALUX assay: comparison between the human TV101L and the rat H4IIE cell line

DEFF Research Database (Denmark)

Long, M.; Laier, Peter; Vinggaard, Anne

2003-01-01

TV101L hepatoma cell lines. In comparison the results indicated that the rat H4IIE cell line is more sensitive than the human TV101L for detection of TCDD inducing AhR-CALUX activity. The pesticides iprodione, chlorpyrifos and prochloraz showed dose-dependent AhR agonistic effects in both cell lines...

Purification of a Multidrug Resistance Transporter for Crystallization Studies

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Kamela O. Alegre

2015-03-01

Full Text Available Crystallization of integral membrane proteins is a challenging field and much effort has been invested in optimizing the overexpression and purification steps needed to obtain milligram amounts of pure, stable, monodisperse protein sample for crystallography studies. Our current work involves the structural and functional characterization of the Escherichia coli multidrug resistance transporter MdtM, a member of the major facilitator superfamily (MFS. Here we present a protocol for isolation of MdtM to increase yields of recombinant protein to the milligram quantities necessary for pursuit of structural studies using X-ray crystallography. Purification of MdtM was enhanced by introduction of an elongated His-tag, followed by identification and subsequent removal of chaperonin contamination. For crystallization trials of MdtM, detergent screening using size exclusion chromatography determined that decylmaltoside (DM was the shortest-chain detergent that maintained the protein in a stable, monodispersed state. Crystallization trials of MdtM performed using the hanging-drop diffusion method with commercially available crystallization screens yielded 3D protein crystals under several different conditions. We contend that the purification protocol described here may be employed for production of high-quality protein of other multidrug efflux members of the MFS, a ubiquitous, physiologically and clinically important class of membrane transporters.

Repurposing ebselen for treatment of multidrug-resistant staphylococcal infections.

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Thangamani, Shankar; Younis, Waleed; Seleem, Mohamed N

2015-06-26

Novel antimicrobials and new approaches to developing them are urgently needed. Repurposing already-approved drugs with well-characterized toxicology and pharmacology is a novel way to reduce the time, cost, and risk associated with antibiotic innovation. Ebselen, an organoselenium compound, is known to be clinically safe and has a well-known pharmacology profile. It has shown potent bactericidal activity against multidrug-resistant clinical isolates of staphylococcus aureus, including methicillin- and vancomycin-resistant S. aureus (MRSA and VRSA). We demonstrated that ebselen acts through inhibition of protein synthesis and subsequently inhibited toxin production in MRSA. Additionally, ebselen was remarkably active and significantly reduced established staphylococcal biofilms. The therapeutic efficacy of ebselen was evaluated in a mouse model of staphylococcal skin infections. Ebselen 1% and 2% significantly reduced the bacterial load and the levels of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), and monocyte chemo attractant protein-1 (MCP-1) in MRSA USA300 skin lesions. Furthermore, it acts synergistically with traditional antimicrobials. This study provides evidence that ebselen has great potential for topical treatment of MRSA skin infections and lays the foundation for further analysis and development of ebselen as a potential treatment for multidrug-resistant staphylococcal infections.

Cytotoxic and multidrug resistance reversal activity of a vegetable, 'Anastasia Red', a variety of sweet pepper.

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Motohashi, Noboru; Wakabayashi, Hidetsugu; Kurihara, Teruo; Takada, Yuko; Maruyama, Shichiro; Sakagami, Hiroshi; Nakashima, Hideki; Tani, Satoru; Shirataki, Yoshiaki; Kawase, Masami; Wolfard, Kristina; Molnár, Joseph

2003-04-01

The vegetable, Anastasia Red, Capsicum annuum L. var. angulosum Mill. (Solanaceae) was successively extracted with hexane, acetone, methanol and 70% methanol, and the extracts were further separated into a total of 21 fractions by silica gel or octadecylsilane (ODS) column chromatography. The biological activities of extracts and fractions were determined. These extracts showed relatively higher cytotoxic activity against two human oral tumor cell lines (HSC-2, HSG) than against normal human gingival fibroblasts (HGF), suggesting a tumor-specific cytotoxic activity. The cytotoxic activity of these extracts was enhanced by fractionation on silica gel [H2, A2, M1-M3] or ODS column chromatography [70M]. Several fractions [H2, H4, H5, A1, A2, A3, A5, A6, A7, M2] reversed the multidrug resistance (MDR) phenotype with L5178 mouse lymphoma T cells, more efficiently than (+/-)-verapamil. The extracts and fractions did not show any detectable anti-human immunodeficiency virus (HIV) or anti-Helicobacter pylori activity. Thus, this study suggests the effective and selective antitumor potential of 'Anastasia Red' of sweet pepper for further phytochemical and biological investigation. Copyright 2003 John Wiley & Sons, Ltd.

Antibiotics: Pharmacokinetics, toxicity, resistance and multidrug efflux pumps.

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Yılmaz, Çiğdem; Özcengiz, Gülay

2017-06-01

The discovery of penicillin followed by streptomycin, tetracycline, cephalosporins and other natural, semi-synthetic and synthetic antimicrobials completely revolutionized medicine by reducing human morbidity and mortality from most of the common infections. However, shortly after they were introduced to clinical practice, the development of resistance was emerged. The decreasing interest from antibiotic industry in spite of rapid global emergence of antibiotic resistance is a tough dilemma from the pointview of public health. The efficiency of antimicrobial treatment is determined by both pharmacokinetics and pharmacodynamics. In spite of their selective toxicity, antibiotics still cause severe, life-threatening adverse reactions in host body mostly due to defective drug metabolism or excessive dosing regimen. The present article aims at updating current knowledge on pharmacokinetics/pharmacodynamics concepts and models, toxicity of antibiotics as well as antibiotic resistance mechanisms, resistome analyses and search for novel antibiotic resistance determinants with special emphasis given to the-state-of-the-art regarding multidrug efflux pumps and their additional physiological functions in stress adaptation and virulence of bacteria. All these issues are highly linked to each other and not only important for most efficient and prolonged use of current antibiotics, but also for discovery and development of new antibiotics and novel inhibitors of antibiotic resistance determinants of pathogens. Copyright © 2016 Elsevier Inc. All rights reserved.

Putative supramolecular complexes formed by carotenoids and xanthophylls with ascorbic acid to reverse multidrug resistance in cancer cells.

Science.gov (United States)

Molnár, József; Serly, Julianna; Pusztai, Rozália; Vincze, Irén; Molnár, Péter; Horváth, Györgyi; Deli, József; Maoka, Takashi; Zalatnai, Attila; Tokuda, Harukuni; Nishino, Hoyoku

2012-02-01

The molecular basis of interaction of selected carotenoids and xanthophylls with ascorbic acid on cancer cells was studied to determine their anticancer effects. Drug accumulation was measured in a human ABCB1 gene-transfected mouse lymphoma cell line and in a human lung cancer cell line by flow cytometry; furthermore, their anticancer effects were determined in mice in vivo. Several carotenoids inhibited the multidrug resistance of cancer cells. Ascorbic acid improved the effect of certain xanthophylls, but the effect of capsanthin was not modified. Capsanthin had weak (12%) but capsorubin (85%) had a remarkable antiproliferative effect on A549 lung cancer cells. Capsorubin reduced immediate-early tumor antigen expression, while capsanthin was not effective. Capsorubin accumulates selectively in the nuclei of cancer cells. The Authors suggest a special complex formation between membrane-bound capsorubin and ascorbic acid, which can be exploited in experimental chemotherapy.

A programmed release multi-drug implant fabricated by three-dimensional printing technology for bone tuberculosis therapy

International Nuclear Information System (INIS)

Wu Weigang; Zheng Qixin; Guo Xiaodong; Sun Jianhua; Liu Yudong

2009-01-01

In the world, bone tuberculosis is still very difficult to treat and presents a challenge to clinicians. In this study, we utilized 3D printing technology to fabricate a programmed release multi-drug implant for bone tuberculosis therapy. The construction of the drug implant was a multi-layered concentric cylinder divided into four layers from the center to the periphery. Isoniazid and rifampicin were distributed individually into the different layers in a specific sequence of isoniazid-rifampicin-isoniazid-rifampicin. The drug release assays in vitro and in vivo showed that isoniazid and rifampicin were released orderly from the outside to the center to form the multi-drug therapeutic alliance, and the peak concentrations of drugs were detected in sequence at 8 to 12 day intervals. In addition, no negative effect on the proliferation of rabbit bone marrow mesenchymal stem cells was detected during the cytocompatibility assay. Due to its ideal pharmacologic action and cytocompatibility, the programmed release multi-drug implant with a complex construction fabricated by 3D printing technology could be of interest in prevention and treatment of bone tuberculosis.

A programmed release multi-drug implant fabricated by three-dimensional printing technology for bone tuberculosis therapy

Energy Technology Data Exchange (ETDEWEB)

Wu Weigang; Zheng Qixin; Guo Xiaodong; Sun Jianhua; Liu Yudong, E-mail: Zheng-qx@163.co [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China)

2009-12-15

In the world, bone tuberculosis is still very difficult to treat and presents a challenge to clinicians. In this study, we utilized 3D printing technology to fabricate a programmed release multi-drug implant for bone tuberculosis therapy. The construction of the drug implant was a multi-layered concentric cylinder divided into four layers from the center to the periphery. Isoniazid and rifampicin were distributed individually into the different layers in a specific sequence of isoniazid-rifampicin-isoniazid-rifampicin. The drug release assays in vitro and in vivo showed that isoniazid and rifampicin were released orderly from the outside to the center to form the multi-drug therapeutic alliance, and the peak concentrations of drugs were detected in sequence at 8 to 12 day intervals. In addition, no negative effect on the proliferation of rabbit bone marrow mesenchymal stem cells was detected during the cytocompatibility assay. Due to its ideal pharmacologic action and cytocompatibility, the programmed release multi-drug implant with a complex construction fabricated by 3D printing technology could be of interest in prevention and treatment of bone tuberculosis.

Doripenem: an expected arrival in the treatment of infections caused by multidrug-resistant Gram-negative pathogens.

Science.gov (United States)

Poulakou, Garyphallia; Giamarellou, Helen

2008-05-01

Potent new drugs against multidrug-resistant Gram-negative bacteria, namely Pseudomonas aeruginosa and Acinetobacter spp. and pan-drug-resistant Klebsiella pneumoniae, which constitute an increasing medical threat, are almost absent from the future pharmaceutical pipeline. This drug evaluation focuses on the position of doripenem, a novel forthcoming carbapenem. Mechanisms of resistance and new drugs with anti-Gram-negative activity are also briefly reviewed. Literature search was performed for new carbapenems, new antibiotics, doripenem, metallo-beta-lactamase inhibitors, multidrug-resistant pathogens, antipseudomonal antibiotics and multidrug-resistant epidemiology. Doripenem possesses a broad spectrum of activity against Gram-negative bacteria, similar to that of meropenem, while retaining the spectrum of imipenem against Gram-positive pathogens. Against P. aeruginosa, doripenem exhibits rapid bactericidal activity with 2 - 4-fold lower MIC values, compared to meropenem. Exploitation of pharmacokinetic/pharmacodynamic applications could offer a treatment opportunity against strains exhibiting borderline resistance to doripenem. Stability against numerous beta-lactamases, low adverse event potential and more potent in vitro antibacterial activity against P. aeruginosa and A. baumanni compared to the existing carbapenems, are its principal features.

Radiation-induced cell disintegrations in cultured rat hepatoma cells JTC 2

International Nuclear Information System (INIS)

Sakka, Masatoshi

1979-01-01

Disintegration of hepatoma cells of rat were recorded by time lapse cinemicrography for more than 5 days and about 1000 pedigrees were analyzed. Five generations were followed up in control and 2 or 3 generations in irradiated cells. Cells were attached on vessel wall spreading themselves in intermitotic phase while they stood up from the wall in mitotic phase taking a roun form. When a cell disintegrates in interphase the disintegration is called D sub( s) and one in mitotic period D sub( r). The frequency of D sub( s)S' is about 3 times as much as D sub( r)S'. An age of a disintegrated cell in generation 1 and 2 was measured as the previous mitosis was age 0. Generation times of the comparable generations of surviving sister branches of the same pedigrees were used as controls. Most disintegration took place at the same age with surviving sisters indicating a determined, not at random, age of cell death. A cell in an initial state flowed to any one of the following states with or without irradiation; surviving, disintegrated, end cell or escaping out of observation field. A single exposure of 400 to 900 R induced a typical reproductive death but effective extinction of clones was observed only in small pedigrees. Temporary hypothermia and hyperthermia immediately after exposure had no remarkable lethal effects on several early generations. (author)

The ABC-Type Multidrug Resistance Transporter LmrCD Is Responsible for an Extrusion-Based Mechanism of Bile Acid Resistance in Lactococcus lactis

NARCIS (Netherlands)

Zaidi, Arsalan Haseeb; Bakkes, Patrick J.; Lubelski, Jacek; Agustiandari, Herfita; Kuipers, Oscar P.; Driessen, Arnold J. M.

2008-01-01

Upon prolonged exposure to cholate and other toxic compounds, Lactococcus lactis develops a multidrug resistance phenotype that has been attributed to an elevated expression of the heterodimeric ABC-type multidrug transporter LmrCD. To investigate the molecular basis of bile acid resistance in L.

Multidrug Efflux Pumps in Staphylococcus aureus: an Update

Science.gov (United States)

Costa, Sofia Santos; Viveiros, Miguel; Amaral, Leonard; Couto, Isabel

2013-01-01

The emergence of infections caused by multi- or pan-resistant bacteria in the hospital or in the community settings is an increasing health concern. Albeit there is no single resistance mechanism behind multiresistance, multidrug efflux pumps, proteins that cells use to detoxify from noxious compounds, seem to play a key role in the emergence of these multidrug resistant (MDR) bacteria. During the last decades, experimental data has established their contribution to low level resistance to antimicrobials in bacteria and their potential role in the appearance of MDR phenotypes, by the extrusion of multiple, unrelated compounds. Recent studies suggest that efflux pumps may be used by the cell as a first-line defense mechanism, avoiding the drug to reach lethal concentrations, until a stable, more efficient alteration occurs, that allows survival in the presence of that agent. In this paper we review the current knowledge on MDR efflux pumps and their intricate regulatory network in Staphylococcus aureus, a major pathogen, responsible from mild to life-threatening infections. Particular emphasis will be given to the potential role that S. aureus MDR efflux pumps, either chromosomal or plasmid-encoded, have on resistance towards different antimicrobial agents and on the selection of drug - resistant strains. We will also discuss the many questions that still remain on the role of each specific efflux pump and the need to establish appropriate methodological approaches to address all these questions. PMID:23569469

Multidrug Efflux Pumps in Staphylococcus aureus: an Update.

Science.gov (United States)

Costa, Sofia Santos; Viveiros, Miguel; Amaral, Leonard; Couto, Isabel

2013-01-01

The emergence of infections caused by multi- or pan-resistant bacteria in the hospital or in the community settings is an increasing health concern. Albeit there is no single resistance mechanism behind multiresistance, multidrug efflux pumps, proteins that cells use to detoxify from noxious compounds, seem to play a key role in the emergence of these multidrug resistant (MDR) bacteria. During the last decades, experimental data has established their contribution to low level resistance to antimicrobials in bacteria and their potential role in the appearance of MDR phenotypes, by the extrusion of multiple, unrelated compounds. Recent studies suggest that efflux pumps may be used by the cell as a first-line defense mechanism, avoiding the drug to reach lethal concentrations, until a stable, more efficient alteration occurs, that allows survival in the presence of that agent. In this paper we review the current knowledge on MDR efflux pumps and their intricate regulatory network in Staphylococcus aureus, a major pathogen, responsible from mild to life-threatening infections. Particular emphasis will be given to the potential role that S. aureus MDR efflux pumps, either chromosomal or plasmid-encoded, have on resistance towards different antimicrobial agents and on the selection of drug - resistant strains. We will also discuss the many questions that still remain on the role of each specific efflux pump and the need to establish appropriate methodological approaches to address all these questions.

Immunological response induced by cryoablation against murine H22 hepatoma cell line in vivo.

Science.gov (United States)

Yang, Xueling; Li, Xiaoli; Guo, Zhi; Si, Tongguo; Yu, Haipeng; Xing, Wenge

2018-02-01

To describe immunological consequences induced by cryoablation against H22 cells in vivo. Adult BALB/c mice underwent subcutaneous implantation of H22 cells. All of them were assigned into three groups randomly: group A (false surgery), group B (cryoablation) and group C (cryoablation plus Freund's adjuvant). Animals were sacrificed 1, 2 and 3 weeks after treatment. Serum IFN-γ and IL-4, Th1/Th2 in spleens and cytotoxicity were detected. Compared with that of group A, (1) INF-γ of group B was higher, but IL-4 was lower; cryoablation plus Freund's adjuvant enhanced these effects. (2) Th1/Th2 rose significantly in both group B and group C. (3) Strong cytolytic activity against H22 cells of group B and group C was found on day 7, 14 and 21. Our study showed a marked shift toward Th1 and IFN-γ expression after cryoablation, with an immuno-stimulatory effect against murine H22 hepatoma Cell. Copyright © 2017. Published by Elsevier Inc.

Antibacterial activities of ethanol extracts of Philippine medicinal plants against multidrug-resistant bacteria

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Demetrio L. Valle Jr.

2015-07-01

Conclusions: P. betle had the greatest potential value against both Gram-negative and Gram-positive multidrug-resistant bacteria. Favorable antagonistic activities were also exhibited by the ethanol extracts of Psidium guajava, Phyllanthus niruri and Ehretia microphylla.

Modulation of P-glycoprotein activity by novel synthetic curcumin derivatives in sensitive and multidrug-resistant T-cell acute lymphoblastic leukemia cell lines

International Nuclear Information System (INIS)

Ooko, Edna; Alsalim, Tahseen; Saeed, Bahjat; Saeed, Mohamed E.M.; Kadioglu, Onat; Abbo, Hanna S.; Titinchi, Salam J.J.; Efferth, Thomas

2016-01-01

Background: Multidrug resistance (MDR) and drug transporter P-glycoprotein (P-gp) represent major obstacles in cancer chemotherapy. We investigated 19 synthetic curcumin derivatives in drug-sensitive acute lymphoblastic CCRF–CEM leukemia cells and their multidrug-resistant P-gp-overexpressing subline, CEM/ADR5000. Material and methods: Cytotoxicity was tested by resazurin assays. Doxorubicin uptake was assessed by flow cytometry. Binding modes of compounds to P-gp were analyzed by molecular docking. Chemical features responsible for bioactivity were studied by quantitative structure activity relationship (QSAR) analyses. A 7-descriptor QSAR model was correlated with doxorubicin uptake values, IC 50 values and binding energies. Results: The compounds displayed IC 50 values between 0.7 ± 0.03 and 20.2 ± 0.25 μM. CEM/ADR5000 cells exhibited cross-resistance to 10 compounds, collateral sensitivity to three compounds and regular sensitivity to the remaining six curcumins. Molecular docking studies at the intra-channel transmembrane domain of human P-gp resulted in lowest binding energies ranging from − 9.00 ± 0.10 to − 6.20 ± 0.02 kcal/mol and pKi values from 0.24 ± 0.04 to 29.17 ± 0.88 μM. At the ATP-binding site of P-gp, lowest binding energies ranged from − 9.78 ± 0.17 to − 6.79 ± 0.01 kcal/mol and pKi values from 0.07 ± 0.02 to 0.03 ± 0.03 μM. CEM/ADR5000 cells accumulated approximately 4-fold less doxorubicin than CCRF–CEM cells. The control P-gp inhibitor, verapamil, partially increased doxorubicin uptake in CEM/ADR5000 cells. Six curcumins increased doxorubicin uptake in resistant cells or even exceeded uptake levels compared to sensitive one. QSAR yielded good activity prediction (R = 0.797 and R = 0.794 for training and test sets). Conclusion: Selected derivatives may serve to guide future design of novel P-gp inhibitors and collateral sensitive drugs to combat MDR. - Highlights: • Novel derivatives of curcumin in reversing multidrug

Modulation of P-glycoprotein activity by novel synthetic curcumin derivatives in sensitive and multidrug-resistant T-cell acute lymphoblastic leukemia cell lines

Energy Technology Data Exchange (ETDEWEB)

Ooko, Edna [Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz (Germany); Alsalim, Tahseen; Saeed, Bahjat [Department of Chemistry, College of Education for Pure Sciences, University of Basrah, P.O. Box 49 Basrah, Al Basrah (Iraq); Saeed, Mohamed E.M.; Kadioglu, Onat [Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz (Germany); Abbo, Hanna S. [Department of Chemistry, University of the Western Cape, P/B X17, Bellville, 7535 Cape Town (South Africa); Titinchi, Salam J.J., E-mail: stitinchi@uwc.ac.za [Department of Chemistry, University of the Western Cape, P/B X17, Bellville, 7535 Cape Town (South Africa); Efferth, Thomas, E-mail: efferth@uni-mainz.de [Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz (Germany)

2016-08-15

Background: Multidrug resistance (MDR) and drug transporter P-glycoprotein (P-gp) represent major obstacles in cancer chemotherapy. We investigated 19 synthetic curcumin derivatives in drug-sensitive acute lymphoblastic CCRF–CEM leukemia cells and their multidrug-resistant P-gp-overexpressing subline, CEM/ADR5000. Material and methods: Cytotoxicity was tested by resazurin assays. Doxorubicin uptake was assessed by flow cytometry. Binding modes of compounds to P-gp were analyzed by molecular docking. Chemical features responsible for bioactivity were studied by quantitative structure activity relationship (QSAR) analyses. A 7-descriptor QSAR model was correlated with doxorubicin uptake values, IC{sub 50} values and binding energies. Results: The compounds displayed IC{sub 50} values between 0.7 ± 0.03 and 20.2 ± 0.25 μM. CEM/ADR5000 cells exhibited cross-resistance to 10 compounds, collateral sensitivity to three compounds and regular sensitivity to the remaining six curcumins. Molecular docking studies at the intra-channel transmembrane domain of human P-gp resulted in lowest binding energies ranging from − 9.00 ± 0.10 to − 6.20 ± 0.02 kcal/mol and pKi values from 0.24 ± 0.04 to 29.17 ± 0.88 μM. At the ATP-binding site of P-gp, lowest binding energies ranged from − 9.78 ± 0.17 to − 6.79 ± 0.01 kcal/mol and pKi values from 0.07 ± 0.02 to 0.03 ± 0.03 μM. CEM/ADR5000 cells accumulated approximately 4-fold less doxorubicin than CCRF–CEM cells. The control P-gp inhibitor, verapamil, partially increased doxorubicin uptake in CEM/ADR5000 cells. Six curcumins increased doxorubicin uptake in resistant cells or even exceeded uptake levels compared to sensitive one. QSAR yielded good activity prediction (R = 0.797 and R = 0.794 for training and test sets). Conclusion: Selected derivatives may serve to guide future design of novel P-gp inhibitors and collateral sensitive drugs to combat MDR. - Highlights: • Novel derivatives of curcumin in reversing

Hepatoma-derived growth factor: A survival-related protein in prostate oncogenesis and a potential target for vitamin K2.

Science.gov (United States)

Shetty, Aditya; Dasari, Subramanyam; Banerjee, Souresh; Gheewala, Taher; Zheng, Guoxing; Chen, Aoshuang; Kajdacsy-Balla, Andre; Bosland, Maarten C; Munirathinam, Gnanasekar

2016-11-01

Hepatoma-derived growth factor (HDGF) is a heparin-binding growth factor, which has previously been shown to be expressed in a variety of cancers. HDGF overexpression has also previously been correlated with a poor prognosis in several cancers. The significance of HDGF in prostate cancer, however, has not been investigated. Here, we show that HDGF is overexpressed in both androgen-sensitive LNCaP cells and androgen-insensitive DU145, 22RV1, and PC-3 cells. Forced overexpression enhanced cell viability of RWPE-1 cells, whereas HDGF knockdown reduced cell proliferation in human prostate cancer cells. We also show that HDGF may serve as a survival-related protein as ectopic overexpression of HDGF in RWPE cells up-regulated the expression of antiapoptosis proteins cyclin E and BCL-2, whereas simultaneously down-regulating proapoptotic protein BAX. Western blot analysis also showed that HDGF overexpression modulated the activity of phospho-AKT as well as NF-kB, and these results correlated with in vitro migration and invasion assays. We next assessed the therapeutic potential of HDGF inhibition with a HDGF monoclonal antibody and vitamin k 2 , showing reduced cell proliferation as well as inhibition of NF-kB expression in HDGF overexpressed RWPE cells treated with a HDGF monoclonal antibody and vitamin K 2 . Collectively, our results suggest that HDGF is a relevant protein in prostate oncogenesis and may serve as a potential therapeutic target in prostate cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of vandetanib as an inhibitor of various human renal transporters: inhibition of multidrug and toxin extrusion as a possible mechanism leading to decreased cisplatin and creatinine clearance.

Science.gov (United States)

Shen, Hong; Yang, Zheng; Zhao, Weiping; Zhang, Yueping; Rodrigues, A David

2013-12-01

Vandetanib was evaluated as an inhibitor of human organic anion transporter 1 (OAT1), OAT3, organic cation transporter 2 (OCT2), and multidrug and toxin extrusion (MATE1 and MATE2K) transfected (individually) into human embryonic kidney 293 cells (HEK293). Although no inhibition of OAT1 and OAT3 was observed, inhibition of OCT2-mediated uptake of 1-methyl-4-phenylpyridinium (MPP(+)) and metformin was evident (IC(50) of 73.4 ± 14.8 and 8.8 ± 1.9 µM, respectively). However, vandetanib was an even more potent inhibitor of MATE1- and MATE2K-mediated uptake of MPP(+) (IC(50) of 1.23 ± 0.05 and 1.26 ± 0.06 µM, respectively) and metformin (IC(50) of 0.16 ± 0.05 and 0.30 ± 0.09 µM, respectively). Subsequent cytotoxicity studies demonstrated that transport inhibition by vandetanib (2.5 µM) significantly decreased the sensitivity [right shift in concentration of cisplatin giving rise to 50% cell death; IC(50(CN))] of MATE1-HEK and MATE2K-HEK cells to cisplatin [IC(50(CN)) of 1.12 ± 0.13 versus 2.39 ± 0.44 µM; 0.85 ± 0.09 versus 1.99 ± 0.16 µM; P cisplatin nephrotoxicity (reduced cisplatin clearance), in some subjects receiving vandetanib therapy.

Cells for bioartificial liver devices: the human hepatoma-derived cell line C3A produces urea but does not detoxify ammonia.

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Mavri-Damelin, Demetra; Damelin, Leonard H; Eaton, Simon; Rees, Myrddin; Selden, Clare; Hodgson, Humphrey J F

2008-02-15

Extrahepatic bioartificial liver devices should provide an intact urea cycle to detoxify ammonia. The C3A cell line, a subclone of the hepatoma-derived HepG2 cell line, is currently used in this context as it produces urea, and this has been assumed to be reflective of ammonia detoxification via a functional urea cycle. However, based on our previous findings of perturbed urea-cycle function in the non-urea producing HepG2 cell line, we hypothesized that the urea produced by C3A cells was via a urea cycle-independent mechanism, namely, due to arginase II activity, and therefore would not detoxify ammonia. Urea was quantified using (15)N-ammonium chloride metabolic labelling with gas chromatography-mass spectrometry. Gene expression was determined by real-time reverse transcriptase-PCR, protein expression by western blotting, and functional activities with radiolabelling enzyme assays. Arginase inhibition studies used N(omega)-hydroxy-nor-L-arginine. Urea was detected in C3A conditioned medium; however, (15)N-ammonium chloride-labelling indicated that (15)N-ammonia was not incorporated into (15)N-labelled urea. Further, gene expression of two urea cycle genes, ornithine transcarbamylase and arginase I, were completely absent. In contrast, arginase II mRNA and protein was expressed at high levels in C3A cells and was inhibited by N(omega)-hydroxy-nor-L-arginine, which prevented urea production, thereby indicating a urea cycle-independent pathway. The urea cycle is non-functional in C3A cells, and their urea production is solely due to the presence of arginase II, which therefore cannot provide ammonia detoxification in a bioartificial liver system. This emphasizes the continued requirement for developing a component capable of a full repertoire of liver function. (c) 2007 Wiley Periodicals, Inc.

DACHPt-Loaded Nanoparticles Self-assembled from Biodegradable Dendritic Copolymer Polyglutamic Acid-b-D-α-Tocopheryl Polyethylene Glycol 1000 Succinate for Multidrug Resistant Lung Cancer Therapy

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Hsiang-I Tsai

2018-02-01

Full Text Available The clinical applications of platinum-based antitumor agents are still largely limited by severe side effects as well as multidrug resistance (MDR. To solve these problems, we developed an 1,2-diaminocyclohexane-platinum(II (DACHPt-loaded nanoparticle (NP-TPGS-Pt by self-assembly of poly(amidoamine-polyglutamic acid-b-D-α-tocopheryl polyethylene glycol 1000 succinate (PAM-PGlu-b-TPGS and DACHPt. NP-TPGS-Pt showed robust stability and pH-responsive DACHPt release profile in vitro similar to the PEG-containing nanoparticle (NP-PEG-Pt. Meanwhile, in contrast with NP-PEG-Pt, NP-TPGS-Pt exhibited efficient nanoparticle-based cellular uptake by the Pt-resistant A549/DDP human lung cancer cells and caused much more cytotoxicity than free Oxaliplatin and NP-PEG-Pt. Finally, this NP-TPGS-Pt was proved to perform outstanding inhibition of Pt-resistant tumor growth, much superior than free Oxaliplatin and NP-PEG-Pt. Thus, this NP-TPGS-Pt provides a novel powerful nanomedicine platform for combatting multidrug resistant cancer.

Ribosomal mutations promote the evolution of antibiotic resistance in a multidrug environment.

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Gomez, James E; Kaufmann-Malaga, Benjamin B; Wivagg, Carl N; Kim, Peter B; Silvis, Melanie R; Renedo, Nikolai; Ioerger, Thomas R; Ahmad, Rushdy; Livny, Jonathan; Fishbein, Skye; Sacchettini, James C; Carr, Steven A; Hung, Deborah T

2017-02-21

Antibiotic resistance arising via chromosomal mutations is typically specific to a particular antibiotic or class of antibiotics. We have identified mutations in genes encoding ribosomal components in Mycobacterium smegmatis that confer resistance to several structurally and mechanistically unrelated classes of antibiotics and enhance survival following heat shock and membrane stress. These mutations affect ribosome assembly and cause large-scale transcriptomic and proteomic changes, including the downregulation of the catalase KatG, an activating enzyme required for isoniazid sensitivity, and upregulation of WhiB7, a transcription factor involved in innate antibiotic resistance. Importantly, while these ribosomal mutations have a fitness cost in antibiotic-free medium, in a multidrug environment they promote the evolution of high-level, target-based resistance. Further, suppressor mutations can then be easily acquired to restore wild-type growth. Thus, ribosomal mutations can serve as stepping-stones in an evolutionary path leading to the emergence of high-level, multidrug resistance.

Functional characterization of the antibiotic resistance reservoir in the human microflora

DEFF Research Database (Denmark)

Sommer, Morten; Church, George M; Dantas, Gautam

2010-01-01

The increasing levels of multi-drug resistance in human pathogenic bacteria are compromising our ability to treat infectious disease. Since antibiotic resistance determinants are readily exchanged between bacteria through lateral gene transfer, there is an increasing interest in investigating res...

Multidrug ATP-binding cassette transporters are essential for hepatic development of Plasmodium sporozoites.

Science.gov (United States)

Rijpma, Sanna R; van der Velden, Maarten; González-Pons, Maria; Annoura, Takeshi; van Schaijk, Ben C L; van Gemert, Geert-Jan; van den Heuvel, Jeroen J M W; Ramesar, Jai; Chevalley-Maurel, Severine; Ploemen, Ivo H; Khan, Shahid M; Franetich, Jean-Francois; Mazier, Dominique; de Wilt, Johannes H W; Serrano, Adelfa E; Russel, Frans G M; Janse, Chris J; Sauerwein, Robert W; Koenderink, Jan B; Franke-Fayard, Blandine M

2016-03-01

Multidrug resistance-associated proteins (MRPs) belong to the C-family of ATP-binding cassette (ABC) transport proteins and are known to transport a variety of physiologically important compounds and to be involved in the extrusion of pharmaceuticals. Rodent malaria parasites encode a single ABC transporter subfamily C protein, whereas human parasites encode two: MRP1 and MRP2. Although associated with drug resistance, their biological function and substrates remain unknown. To elucidate the role of MRP throughout the parasite life cycle, Plasmodium berghei and Plasmodium falciparum mutants lacking MRP expression were generated. P. berghei mutants lacking expression of the single MRP as well as P. falciparum mutants lacking MRP1, MRP2 or both proteins have similar blood stage growth kinetics and drug-sensitivity profiles as wild type parasites. We show that MRP1-deficient parasites readily invade primary human hepatocytes and develop into mature liver stages. In contrast, both P. falciparum MRP2-deficient parasites and P. berghei mutants lacking MRP protein expression abort in mid to late liver stage development, failing to produce mature liver stages. The combined P. berghei and P. falciparum data are the first demonstration of a critical role of an ABC transporter during Plasmodium liver stage development. © 2015 John Wiley & Sons Ltd.

Tigecycline use in two cases with multidrug-resistant Acinetobacter baumannii meningitis.

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Tutuncu, E Ediz; Kuscu, Ferit; Gurbuz, Yunus; Ozturk, Baris; Haykir, Asli; Sencan, Irfan

2010-09-01

The treatment of post-surgical meningitis due to multidrug-resistant (MDR) Acinetobacter baumannii is a therapeutic dilemma. The cases of two patients with MDR A. baumannii meningitis secondary to surgical site infections, successfully treated with combination regimens including tigecycline, are presented. Copyright © 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Identification and characterization of SSE15206, a microtubule depolymerizing agent that overcomes multidrug resistance

KAUST Repository

Manzoor, Safia

2018-02-13

Microtubules are highly dynamic structures that form spindle fibres during mitosis and are one of the most validated cancer targets. The success of drugs targeting microtubules, however, is often limited by the development of multidrug resistance. Here we describe the discovery and characterization of SSE15206, a pyrazolinethioamide derivative [3-phenyl-5-(3,4,5-trimethoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide] that has potent antiproliferative activities in cancer cell lines of different origins and overcomes resistance to microtubule-targeting agents. Treatment of cells with SSE15206 causes aberrant mitosis resulting in G2/M arrest due to incomplete spindle formation, a phenotype often associated with drugs that interfere with microtubule dynamics. SSE15206 inhibits microtubule polymerization both in biochemical and cellular assays by binding to colchicine site in tubulin as shown by docking and competition studies. Prolonged treatment of cells with the compound results in apoptotic cell death [increased Poly (ADP-ribose) polymerase cleavage and Annexin V/PI staining] accompanied by p53 induction. More importantly, we demonstrate that SSE15206 is able to overcome resistance to chemotherapeutic drugs in different cancer cell lines including multidrug-resistant KB-V1 and A2780-Pac-Res cell lines overexpressing MDR-1, making it a promising hit for the lead optimization studies to target multidrug resistance.

Converging risk factors but no association between HIV infection and multidrug-resistant tuberculosis in Kazakhstan.

Science.gov (United States)

van den Hof, S; Tursynbayeva, A; Abildaev, T; Adenov, M; Pak, S; Bekembayeva, G; Ismailov, S

2013-04-01

Kazakhstan is a country with a low HIV/AIDS (human immunodeficiency virus/acquired immune-deficiency syndrome) burden, but a high prevalence of multidrug-resistant tuberculosis (MDR-TB). We describe the epidemiology of multidrug resistance and HIV among TB patients, using the 2007-2011 national electronic TB register. HIV test results were available for 97.2% of TB patients. HIV prevalence among TB patients increased from 0.6% in 2007 to 1.5% in 2011. Overall, 41.6% of patients had a positive smear at diagnosis, 38.6% a positive culture and 51.7% either a positive smear or culture. Drug susceptibility testing (DST) results were available for 92.7% of culture-positive cases. Socio-economic factors independently associated with both HIV and MDR-TB were urban residency, drug use, homelessness and a history of incarceration. In adjusted analysis, HIV positivity was not associated with MDR-TB (OR 1.0, 95%CI 0.86-1.2). Overall, among TB patients with DST and HIV test results available, 65.0% were positive for neither HIV nor MDR-TB, 33.5% only for MDR-TB, 0.9% only for HIV and 0.6% for both HIV and MDR-TB. Among injection drug users, 12.5% were positive for HIV and MDR-TB. We showed increasing HIV prevalence among TB patients in Kazakhstan. HIV was not an independent risk factor for MDR-TB, but risk factors were largely overlapping and we did identify subgroups at particular risk of HIV-MDR-TB co-infection, notably drug users. Enhanced efforts are necessary to provide care to these socially vulnerable populations.

Distribution and physiology of ABC-Type transporters contributing to multidrug resistance in bacteria

NARCIS (Netherlands)

Lubelski, Jacek; Konings, Wil N.; Driessen, Arnold J. M.

Membrane proteins responsible for the active efflux of structurally and functionally unrelated drugs were first characterized in higher eukalyotes. To date, a vast number of transporters contributing to multidrug resistance (MDR transporters) have been reported for a large variety of organisms.

Genetic characterisation of multidrug-resistant Salmonella enterica serotypes isolated from poultry in Cairo, Egypt

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Mohammed Abdel-Maksoud

2015-05-01

Full Text Available Background: Food-borne diseases pose serious health problems, affecting public health and economic development worldwide. Methods: Salmonella was isolated from samples of chicken parts, skin samples of whole chicken carcasses, raw egg yolks, eggshells and chicken faeces. Resulting isolates were characterised by serogrouping, serotyping, antimicrobial susceptibility testing and detection of extended-spectrum β-lactamase (ESBL production. Antibiotic resistance genes and integrons were identified by polymerase chain reaction (PCR. Results: The detection rates of Salmonella were 60%, 64% and 62% in chicken parts, skin, and faeces, respectively, whereas the egg yolks and eggshells were uniformly negative. Salmonella Kentucky and S. Enteritidis serotypes comprised 43.6% and 2.6% of the isolates, respectively, whilst S. Typhimurium was absent. Variable resistance rates were observed against 16 antibiotics; 97% were resistant to sulfamethoxazole, 96% to nalidixic acid and tetracycline and 76% to ampicillin. Multidrug resistance was detected in 82% (64/78 of the isolates and ESBL production was detected in 8% (6/78. The β-lactamase blaTEM-1 gene was detected in 57.6% and blaSHV-1 in 6.8% of the isolates, whilst the blaOXA gene was absent. The sul1gene was detected in 97.3% and the sul2 gene in 5.3% of the isolates. Sixty-four of the 78 isolates (82% were positive for the integrase gene (int I from class 1 integrons, whilst int II was absent. Conclusion: This study reveals the presence of an alarming number of multidrug-resistant Salmonella isolates in the local poultry markets in Cairo. The high levels of drug resistance suggest an emerging problem that could impact negatively on efforts to prevent and treat poultry and poultry-transmitted human diseases in Egypt.

Characterization and purification of a bacteriocin from Lactobacillus paracasei subsp. paracasei BMK2005, an intestinal isolate active against multidrug-resistant pathogens.

Science.gov (United States)

Bendjeddou, Kamel; Fons, Michel; Strocker, Pierre; Sadoun, Djamila

2012-04-01

A strain of Lactobacillus paracasei subsp. paracasei BMK2005 isolated from healthy infant faeces has shown a remarkable antibacterial activity against 32 bacterial pathogenic strains of human clinical isolates. Among them, 13 strains belonging to species of Escherichia coli, Citrobacter freundii, Citrobacter diversus, Klebsiella oxytoca, Enterobacter cloacae and Pseudomonas aeruginosa were resistant to Cefotaxime (CTX) and Ceftazidime (CAZ), and 4 strains of Staphylococcus aureus were resistant to Methicillin (MRSA). This antibacterial activity was attributed to a bacteriocin designated as Paracaseicin A. It was heat-stable up to 120°C for 5 min and active within the pH range of 2-5. Its activity was lost when treated with proteases, which reveals its proteinaceous nature. This bacteriocin was successfully purified only by two steps of reversed phase chromatography. Its molecular mass, determined by mass spectrometry analysis, was 2,462.5 Da. To our knowledge, the present study is the first report on characterization and purification of a bacteriocin, produced by a L. paracasei subsp. paracasei strain exhibiting an antibacterial activity against various multidrug-resistant species of Gram-positive and Gram-negative bacteria, which reveals its potential for use in prevention or treatment of infections caused by multidrug-resistant species especially in cases of antibiotics-associated diarrhea (AAD).

Bactericidal activity of herbal volatile oil extracts against multidrug-resistant Acinetobacter baumannii.

Science.gov (United States)

Intorasoot, Amornrat; Chornchoem, Piyaorn; Sookkhee, Siriwoot; Intorasoot, Sorasak

2017-01-01

The aim of the study is to investigate the antibacterial activity of 10 volatile oils extracted from medicinal plants, including galangal ( Alpinia galanga Linn.), ginger ( Zingiber officinale ), plai ( Zingiber cassumunar Roxb.), lime ( Citrus aurantifolia ), kaffir lime ( Citrus hystrix DC.), sweet basil ( Ocimum basilicum Linn.), tree basil ( Ocimum gratissimum ), lemongrass ( Cymbopogon citratus DC.), clove ( Syzygium aromaticum ), and cinnamon ( Cinnamomum verum ) against four standard strains of Staphylococcus aureus , Escherichia coli , Pseudomonas aeruginosa , Acinetobacter baumannii , and 30 clinical isolates of multidrug-resistant A. baumannii (MDR- A. baumannii ). Agar diffusion, minimum inhibitory concentration, and minimum bactericidal concentration (MBC) were employed for the determination of bactericidal activity of water distilled medicinal plants. Tea tree oil ( Melaleuca alternifolia ) was used as positive control in this study. The results indicated the volatile oil extracted from cinnamon exhibited potent antibacterial activity against the most common human pathogens, S. aureus , E. coli , P. aeruginosa , and A. baumannii . Most of volatile oil extracts were less effective against non-fermentative bacteria, P. aeruginosa . In addition, volatile oil extracted from cinnamon, clove, and tree basil possessed potent bactericidal activity against MDR- A. baumannii with MBC 90 of 0.5, 1, and 2 mg/mL, respectively. The volatile oil extracts would be useful as alternative natural product for the treatment of the most common human pathogens and MDR- A. baumannii infections.

Antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model: implications for prophylaxis and treatment of combat-related wound infections.

Science.gov (United States)

Zhang, Yunsong; Zhu, Yingbo; Gupta, Asheesh; Huang, Yingying; Murray, Clinton K; Vrahas, Mark S; Sherwood, Margaret E; Baer, David G; Hamblin, Michael R; Dai, Tianhong

2014-06-15

In this study, we investigated the utility of antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model. A bioluminescent clinical isolate of multidrug-resistant A. baumannii was obtained. The susceptibility of A. baumannii to blue light (415 nm)-inactivation was compared in vitro to that of human keratinocytes. Repeated cycles of sublethal inactivation of bacterial by blue light were performed to investigate the potential resistance development of A. baumannii to blue light. A mouse model of third degree burn infected with A. baumannii was developed. A single exposure of blue light was initiated 30 minutes after bacterial inoculation to inactivate A. baumannii in mouse burns. It was found that the multidrug-resistant A. baumannii strain was significantly more susceptible than keratinocytes to blue light inactivation. Transmission electron microscopy revealed blue light-induced ultrastructural damage in A. baumannii cells. Fluorescence spectroscopy suggested that endogenous porphyrins exist in A. baumannii cells. Blue light at an exposure of 55.8 J/cm(2) significantly reduced the bacterial burden in mouse burns. No resistance development to blue light inactivation was observed in A. baumannii after 10 cycles of sublethal inactivation of bacteria. No significant DNA damage was detected in mouse skin by means of a skin TUNEL assay after a blue light exposure of 195 J/cm(2). © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Several Virulence Factors of Multidrug-Resistant Staphylococcus aureus Isolates From Hospitalized Patients in Tehran

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Abdolmajid Ghasemian

2015-05-01

Full Text Available Background: Biofilm formation plays an important role in resistance of Staphylococcus aureus isolates; especially multidrug-resistant isolates are a threat to healthcare settings. Objectives: The aims of this study were to detect biofilm formation and presence of several related genes among multidrug-resistant (MDR isolates of Staphylococcus aureus. Patients and Methods: A total Of 209 S. aureus strains were isolated from patients and identified by conventional diagnostic tests. The multidrug-resistant MRSA isolates were detected by antibiotic susceptibility test. The phenotypic biofilm formation was detected by micro-titre tissue plate assay. The polymerase chain reaction (PCR was performed to detect the mecA, Staphylococcal Cassette Chromosome mec (SCCmec types, accessory gene regulatory (agr genes, the icaADBC and several genes encoding staphylococcal surface proteins including clfAB, fnbAB, fib, eno, can, ebps and bbp genes with specific primers. Results: Sixty-four (30.6% isolates were methicillin-resistant, among which thirty-six (56.2% were MDR. These isolates were resistant to amoxicillin, tetracycline, ciprofloxacin, gentamicin, erythromycin and trimethoprim-sulfamethoxazole (except to 6 isolates. All the isolates were susceptible to vancomycin and linezolid. All the MDR-MRSA harbored SCCmec type III. All the MDR- MRSA isolates were strong biofilm producers in the phenotypic test. The majority of MDR- MRSA was belonged to agrI (67%, n = 24, followed by agr II (17%, n = 6, agrIV (11%, n = 4 and agrIII (5.5%, n = 2. The frequency of icaADBC genes were 75% (n = 27, 61% (n = 22, 72% (n = 26 and 72% (n = 26, respectively. Furthermore, the prevalence of clfA, clfB, fnbA, fnbB, fib, can, eno, ebps and bbp genes was 100%, 100%, 67%, 56%, 80%, 63%, 78%, 7% and 0%, respectively. Furthermore, approximately all the MRSA was strong biofilm producers. Conclusions: Multidrug-resistant isolates produced biofilm strongly and the majority harbored most

New Roads Leading to Old Destinations: Efflux Pumps as Targets to Reverse Multidrug Resistance in Bacteria

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Gabriella Spengler

2017-03-01

Full Text Available Multidrug resistance (MDR has appeared in response to selective pressures resulting from the incorrect use of antibiotics and other antimicrobials. This inappropriate application and mismanagement of antibiotics have led to serious problems in the therapy of infectious diseases. Bacteria can develop resistance by various mechanisms and one of the most important factors resulting in MDR is efflux pump-mediated resistance. Because of the importance of the efflux-related multidrug resistance the development of new therapeutic approaches aiming to inhibit bacterial efflux pumps is a promising way to combat bacteria having over-expressed MDR efflux systems. The definition of an efflux pump inhibitor (EPI includes the ability to render the bacterium increasingly more sensitive to a given antibiotic or even reverse the multidrug resistant phenotype. In the recent years numerous EPIs have been developed, although so far their clinical application has not yet been achieved due to their in vivo toxicity and side effects. In this review, we aim to give a short overview of efflux mediated resistance in bacteria, EPI compounds of plant and synthetic origin, and the possible methods to investigate and screen EPI compounds in bacterial systems.

Concentration of sup(99m)Tc-Sn-N-pyridoxyl-5-methyltryptophan, a biliary agent, in distant metastases of hepatomas

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Y; Nakano, S; Ibuka, K; Hashizume, T; Sasaki, Y; Imaoka, S; Ishiguro, S; Tanaka, S; Kasugai, H; Okano, Y

1985-03-01

During the last 2 years, eight patients with hepatocellular carcinoma who were suspected of having distant metastases have been studied to determine whether a new biliary agent, sup(99m)Tc-Sn-N-pyridoxyl-5-methyl-tryptophan (sup(99m)Tc-PMT), is taken up by extrahepatic tumors. In all eight patients, scintigrams showed a clearly increased uptake of sup(99m)Tc-PMT radioactivity by the extrahepatic tumors. In contrast, an increased uptake by the tumors of gallium citrate Ga 67 was only detected in four of the seven patients examined. The results obtained in this study suggest that sup(99m)Tc-PMT is useful both for characterizing the nature of extrahepatic tumors in patients with hepatoma and for detecting the metastases.

Dioxin-like activity of brominated dioxins as individual compounds or mixtures in in vitro reporter gene assays with rat and mouse hepatoma cell lines.

Science.gov (United States)

Suzuki, G; Nakamura, M; Michinaka, C; Tue, N M; Handa, H; Takigami, H

2017-10-01

In vitro reporter gene assays detecting dioxin-like compounds have been developed and validated since the middle 1990's, and applied to the determination of dioxin-like activities in various samples for their risk management. Data on characterizing the potency of individual brominated dioxins and their activity in mixture with chlorinated dioxins are still limited on the cell-based assay. This study characterized the dioxin-like activities of the 32 brominated dioxins, such as polybrominated dibenzo-p-dioxins, polybrominated dibenzofurans (PBDFs), coplanar polybrominated biphenyls, mixed halogenated dibenzo-p-dioxins and dibenzofurans (PXDFs), as a sole component or in a mixture by DR-CALUX (dioxin-responsive chemically activated luciferase expression) using the rat hepatoma H4IIE cell line and XDS-CALUX (xenobiotic detection systems-chemically activated luciferase expression) assays using the mouse hepatoma H1L6.1 cell line. The 2,3,7,8-TCDD-relative potencies (REPs) of most of the brominated dioxins were within a factor of 10 of the WHO toxicity equivalency factor (WHO-TEF) for the chlorinated analogues. The REPs of a few PXDFs were an order of magnitude higher than the corresponding WHO-TEFs, indicating their toxicological importance. Results with reconstituted mixtures suggest that the activity of brominated and chlorinated dioxins in both CALUX assays was dose-additive. Thus, obtained results indicated the applicability of the CALUX assays as screening tools of brominated dioxins together with their chlorinated analogues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Conspicuous multidrug-resistant Mycobacterium tuberculosis cluster strains do not trespass country borders in Latin America and Spain.

Science.gov (United States)

Ritacco, Viviana; Iglesias, María-José; Ferrazoli, Lucilaine; Monteserin, Johana; Dalla Costa, Elis R; Cebollada, Alberto; Morcillo, Nora; Robledo, Jaime; de Waard, Jacobus H; Araya, Pamela; Aristimuño, Liselotte; Díaz, Raúl; Gavin, Patricia; Imperiale, Belen; Simonsen, Vera; Zapata, Elsa M; Jiménez, María S; Rossetti, Maria L; Martin, Carlos; Barrera, Lucía; Samper, Sofia

2012-06-01

Multidrug-resistant Mycobacterium tuberculosis strain diversity in Ibero-America was examined by comparing extant genotype collections in national or state tuberculosis networks. To this end, genotypes from over 1000 patients with multidrug-resistant tuberculosis diagnosed from 2004 through 2008 in Argentina, Brazil, Chile, Colombia, Venezuela and Spain were compared in a database constructed ad hoc. Most of the 116 clusters identified by IS6110 restriction fragment length polymorphism were small and restricted to individual countries. The three largest clusters, of 116, 49 and 25 patients, were found in Argentina and corresponded to previously documented locally-epidemic strains. Only 13 small clusters involved more than one country, altogether accounting for 41 patients, of whom 13 were, in turn, immigrants from Latin American countries different from those participating in the study (Peru, Ecuador and Bolivia). Most of these international clusters belonged either to the emerging RD(Rio) LAM lineage or to the Haarlem family of M. tuberculosis and four were further split by country when analyzed with spoligotyping and rifampin resistance-conferring mutations, suggesting that they did not represent ongoing transnational transmission events. The Beijing genotype accounted for 1.3% and 10.2% of patients with multidrug-resistant tuberculosis in Latin America and Spain, respectively, including one international cluster of two cases. In brief, Euro-American genotypes were widely predominant among multidrug-resistant M. tuberculosis strains in Ibero-America, reflecting closely their predominance in the general M. tuberculosis population in the region, and no evidence was found of acknowledged outbreak strains trespassing country borders. Copyright © 2011 Elsevier B.V. All rights reserved.

Detection of multidrug resistance using molecular nuclear technique

International Nuclear Information System (INIS)

Lee, Jae Tae; Ahn, Byeong Cheol

2004-01-01

Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. 99 m-Tc-MIBI and other 99 m-Tc-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of Pgp-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with 11 C have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and N-( 11 C)acetyl-leukotriene E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo

Insulin regulation of Na/K pump activity in rat hepatoma cells

International Nuclear Information System (INIS)

Gelehrter, T.D.; Shreve, P.D.; Dilworth, V.M.

1984-01-01

Insulin rapidly increases Na/K pump activity in HTC rat hepatoma cells in tissue culture, as measured by the ouabain-sensitive influx of the potassium analogue 86Rb+. Increased influx is observed within minutes and is maximal (70% above control) within 1-2 h. The effect appears to be mediated by the insulin receptors, as: the concentration dependence on insulin is identical to that for insulin induction of tyrosine aminotransferase and stimulation of 2-aminoisobutyric acid transport, proinsulin is 6% as potent as insulin, and the effect is blocked by anti-receptor antibodies. The early stimulation of potassium influx is not blocked by cycloheximide and is not associated with an increased number of pump sites as measured by 3 H-ouabain binding. The insulin effect is blocked by amiloride, which blocks sodium influx, and is mimicked by the sodium ionophore monensin, which increases sodium influx and intracellular accumulation. Insulin also rapidly increases the initial rate of 22 Na+ influx, suggesting that insulin may enhance Na/K pump activity, in part, by increasing intracellular sodium concentration. Incubation of HTC cells with insulin for 24 h causes complete unresponsiveness to the insulin induction of transaminase and stimulation of amino acid transport, a phenomenon mediated by postbinding mechanisms. In contrast, similar incubation with insulin does not cause unresponsiveness to the insulin stimulation of Na/K pump activity. Therefore, the site of regulation of responsiveness to insulin must be distal to, or separate from, those events causing stimulation of ion fluxes

Bodipy-FL-Verapamil: A Fluorescent Probe for the Study of Multidrug Resistance Proteins

Directory of Open Access Journals (Sweden)

Anna Rosati

2004-01-01

Full Text Available Most of the substances used as fluorescent probes to study drug transport and the effect of efflux blockers in multidrug resistant cells have many drawbacks, such as toxicity, unspecific background, accumulation in mitochondria. New fluorescent compounds, among which Bodipy‐FL‐verapamil (BV, have been therefore proposed as more useful tools. The uptake of BV has been evaluated by cytofluorimetry and fluorescence microscopy using cell lines that overexpress P‐glycoprotein (P388/ADR and LLC‐PK1/ADR or MRP (multidrug resistance‐related protein (PANC‐1 and clinical specimens from patients. The effect of specific inhibitors for P‐glycoprotein (verapamil and vinblastine or MRP (MK571 and probenecid has been also studied. BV intracellular concentrations were significantly lower in the two P‐glycoprotein overexpressing cell lines in comparison with the parental lines. In addition, verapamil and vinblastine increased the intracellular concentrations of the dye; MK571 and probenecid, two MRP inhibitors, increased BV levels in PANC‐1 cells, that express this protein. These findings were confirmed in clinical specimens from patients. Fluorescence microscopy revealed a faint fluorescence emission in P‐glycoprotein or MRP expressing cell lines; however, treatment with specific inhibitors significantly increased the fluorescence. BV is a useful tool for studying multidrug resistance proteins with different techniques such as cytofluorimetry and fluorescence microscopy, but does not discriminate between P‐glycoprotein and MRP. In comparison with other classic fluorescent probes, the assay with this dye is extremely rapid, simple, not toxic for cells, devoid of fluorescent background, and can be useful in the clinical settings.

Phenotypic and genotypic profile of clinical and animal multidrug-resistant Salmonella enterica isolates from Mexico.

Science.gov (United States)

Aguilar-Montes de Oca, S; Talavera-Rojas, M; Soriano-Vargas, E; Barba-León, J; Vázquez-Navarrete, J; Acosta-Dibarrat, J; Salgado-Miranda, C

2018-01-01

The objective of this study was to obtain a phenotypic and genotypic profile of Salmonella enterica including multidrug-resistant (MDR) isolates from food-producing animals and clinical isolates, as well as their genetic relatedness in two different States of Mexico (Jalisco and State of Mexico). A total of 243 isolates were evaluated in terms of antimicrobial resistance (AMR) and related genes through a disk diffusion method and PCR respectively; we found 16 MDR isolates, all of them harbouring the bla CMY gene but not qnr genes, these isolates represent less than 10% of the collection. The pulsed-field gel electrophoresis revealed a higher genotypic similitude within isolates of State of Mexico than Jalisco. A low percentage of Salmonella isolates were resistant to relevant antibiotics in human health, nevertheless, the AMR and involved genes were similar despite the different serovars and origin of the isolates. This investigation provided an insight of the current status of AMR of Salmonella isolates in two States of Mexico and pinpoint the genes involved in AMR and their epidemiological relationship, the information could help to determine an adequate therapy in human and veterinary medicine. © 2017 The Society for Applied Microbiology.