bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro susceptibility to quinine and microsatellite variations of the Plasmodium falciparum Na+/H+ exchanger (Pfnhe-1) gene: the absence of association in clinical isolates from the Republic of Congo
Authors: Briolant Sébastien , Pelleau Stéphane , Bogreau Hervé , Hovette Philippe , Zettor Agnès , Castello Jacky , Baret Eric , Amalvict Rémy , Rogier Christophe , Pradines Bruno 
Published: February 2011

Abstract

Background
Quinine is still recommended as an effective therapy for severe cases of Plasmodium falciparum malaria, but the parasite has developed resistance to the drug in some cases. Investigations into the genetic basis for quinine resistance (QNR) suggest that QNR is complex and involves several genes, with either an additive or a pairwise effect. The results obtained when assessing one of these genes, the plasmodial Na+/H+ exchanger, Pfnhe-1, were found to depend upon the geographic origin of the parasite strain. Most of the associations identified have been made in Asian strains; in contrast, in African strains, the influence of Pfnhe on QNR is not apparent. However, a recent study carried out in Kenya did show a significant association between a Pfnhe polymorphism and QNR. As genetic differences may exist across the African continent, more field data are needed to determine if this association exists in other African regions. In the present study, association between Pfnhe and QNR is investigated in a series of isolates from central Africa.

Methods
The sequence analysis of the polymorphisms at the Pfnhe-1 ms4760 microsatellite and the evaluation of in vitro quinine susceptibility (by isotopic assay) were conducted in 74 P. falciparum isolates from the Republic of Congo.

Results
Polymorphisms in the number of DNNND or NHNDNHNNDDD repeats in the Pfnhe-1 ms4760 microsatellite were not associated with quinine susceptibility.

Conclusions
The polymorphism in the microsatellite ms4760 in Pfnhe-1 that cannot be used to monitor quinine response in the regions of the Republic of Congo, where the isolates came from. This finding suggests that there exists a genetic background associated with geographic area for the association that will prevent the use of Pfnhe as a molecular marker for QNR. The contribution of Pfnhe to the in vitro response to quinine remains to be assessed in other regions, including in countries with different levels of drug pressure.
Soluble Frizzled-7 receptor inhibits Wnt signaling and sensitizes hepatocellular carcinoma cells towards doxorubicin
Authors: Wei Wei , Chua Mei-Sze , Grepper Susan , So Samuel K 
Published: February 2011

AbstractBackgroundThere are limited therapeutic options for hepatocellular carcinoma (HCC), the most common liver malignancy worldwide. Recent studies have identified the Frizzled-7 receptor (FZD7), important for activation of Wnt-mediated signaling, as a potential therapeutic target for HCC and other cancers.MethodsWe hypothesized that the extracellular domain of FZD7 (sFZD7) would be a clinically more relevant therapeutic modality than previously studied approaches to target FZD7. We expressed and purified sFZD7 from E. coli, and tested its functional activity to interact with Wnt3, its ability to inhibit Wnt3-mediated signaling, and its potential for combinatorial therapy in HCC.ResultssFZD7 pulled down Wnt3 from Huh7 cells, and decreased β-catenin/Tcf4 transcriptional activity in HCC cells.In vitro, sFZD7 dose-dependently decreased viability of three HCC cell lines (HepG2, Hep40, and Huh7, all with high FZD7 and Wnt3 mRNA), but had little effect on normal hepatocytes from three donors (all with low level FZD7 and Wnt3 mRNA). When combined with doxorubicin, sFZD7 enhanced the growth inhibitory effects of doxorubicin against HCC cellsin vitro, and against Huh7 xenograftsin vivo. Reduced expressions of c-Myc, cyclin D1, and survivin were observedin vitroandin vivo. Additionally, sFZD7 altered the levels of phosphorylated AKT and ERK1/2 induced by doxorubicin treatmentin vitro, suggesting that several critical pathways are involved in the chemosensitizing effect of sFZD7.ConclusionsWe propose that sFZD7 is a feasible therapeutic agent with specific activity, which can potentially be combined with other chemotherapeutic agents for the improved management of HCC.
In vitro study of the PLA2 inhibition and antioxidant activities of Aloe vera leaf skin extracts
Authors: Kammoun Maher , Miladi Sonia , Ali Yassine Ben , Damak Mohamed , Gargouri Youssef , Bezzine Sofiane 
Published: February 2011

AbstractBackgroundIn the present work we determined the total phenolic content ofAloe veraleaf skin (AVLS) extracts by using various solvents (hexane, chloroform-ethanol (1/1), ethyl acetate, butanol and water). We have also evaluated the antioxidant and the anti-PLA2 properties of these extracts by measuring their inhibition potency on the human pro-inflammatory phospholipase A2 (group IIA).ResultsThe water extract exhibits the highest inhibitory effect with an IC50= 0.22 mg/ml and interestingly no effect was observed on the digestive phospholipase A2 (group IB) even at a concentration of 5 mg/ml. Antioxidant activities were also analyzed and the most active extracts were observed when using chloroform ethanol (1/1) and ethyl acetate (IC50= 0.274 and 0.326 mg/ml, respectively). Analysis of the total phenolic content reveals that the water extract, with the best anti-PLA2 effect, was poor in phenolic molecules (2 mg GAE/g). This latter value has to be compared with the chloroform-ethanol and the ethyl acetate extracts (40 and 23.8 mg GAE/g, respectively), mostly responsible for the antioxidant activity.ConclusionA significant correlation was established between the total phenolic content and the antioxidant capacity but not with the anti PLA2 activity. Results from phytochemical screening suggest that the anti PLA2 molecules were probably catechin tannins compounds.
Biochemical isolation and purification of ovulation-inducing factor (OIF) in seminal plasma of llamas
Authors: Ratto Marcelo H , Delbaere Louis TJ , Leduc Yvonne A , Pierson Roger A , Adams Gregg P 
Published: February 2011

Abstract

Background
The objective of the present study was to isolate and purify the protein fraction(s) of llama seminal plasma responsible for the ovulation-inducing effect of the ejaculate.

Methods
Semen collected from male llamas by artificial vagina was centrifuged and the seminal plasma was harvested and stored frozen. Seminal plasma was thawed and loaded onto a Type 1 macro-prep ceramic hydroxylapatite column and elution was carried out using a lineal gradient with 350 mM sodium phosphate. Three protein fractions were identified clearly (Fractions A, B, and C), where a prominent protein band with a mass of 14 kDa was identified in Fraction C. Fraction C was loaded into a sephacryl gel filtration column for further purification using fast protein liquid chromatography (FPLC). Isocratic elution resulted in 2 distinct protein fractions (Fractions C1 and C2). An in vivo bioassay (n = 10 to 11 llamas per group) was used to determine the ovarian effect of each fraction involving treatment with saline (negative control), whole seminal plasma (positive control), or seminal plasma Fractions A, B or C2. Ultrasonography was done to detect ovulation and CL formation, and blood samples were taken to measure plasma progesterone and LH concentrations.

Results
Ovulation and CL formation was detected in 0/10, 10/11, 0/10, 2/11, and 10/11 llamas treated with saline, whole seminal plasma, Fractions A, B and C2 respectively (P < 0.001). A surge in circulating concentrations of LH was detected within 2 hours only in llamas treated with either whole seminal plasma or Fraction C2. Plasma progesterone concentration and CL diameter profiles were greatest (P < 0.05) in llamas treated with Fraction C2.

Conclusion
Ovulation-inducing factor was isolated from llama seminal plasma as a 14 kDa protein molecule that elicits a preovulatory LH surge followed by ovulation and CL formation in llamas, suggesting an endocrine effect at the level of the hypothalamus (release of GnRH) or the pituitary (gonadotrophs).
Decentralization of the provision of health services to people living with HIV/AIDS in rural China: the case of three counties
Authors: Zhang Xiulan , Miège Pierre , Zhang Yurong 
Published: February 2011

Abstract
This study is based on a large-scale household survey and in-depth interviews of key informants that was conducted in villages in three counties of two provinces in China. We assess the new decentralized service provision system for people living with HIV/AIDS in rural populations in China. Since 2003, new social assistance schemes, and, more importantly, decentralization of routine treatment and care to community health stations, were progressively implemented in rural areas most affected by the HIV/AIDS epidemic. Though some problems remain, such as persistent discrimination towards infected patients and the lack of sufficient training of medical staff, the new decentralized pattern of service provision has lowered barriers to health access and alleviated economic pressure on affected households.
On the direct insulator-quantum Hall transition in two-dimensional electron systems in the vicinity of nanoscaled scatterers
Authors: Liang Chi-Te , Lin Li-Hung , Kuang Yoa Chen , Lo Shun-Tsung , Wang Yi-Ting , Lou Dong-Sheng , Kim Gil-Ho , Yuan-Huei Chang , Ochiai Yuichi , Aoki Nobuyuki , Chen Jeng-Chung , Lin Yiping , Chun-Feng Huang , Lin Sheng-Di , Ritchie David A 
Published: February 2011

AbstractA direct insulator-quantum Hall (I-QH) transition corresponds to a crossover/transition from the insulating regime to a high Landau level filling factor ν > 2 QH state. Such a transition has been attracting a great deal of both experimental and theoretical interests. In this study, we present three different two-dimensional electron systems (2DESs) which are in the vicinity of nanoscaled scatterers. All these three devices exhibit a direct I-QH transition, and the transport properties under different nanaoscaled scatterers are discussed.
Near-surface processing on AlGaN/GaN heterostructures: a nanoscale electrical and structural characterization
Authors: Greco Giuseppe , Giannazzo Filippo , Frazzetto Alessia , Raineri Vito , Roccaforte Fabrizio 
Published: February 2011

AbstractThe effects of near-surface processing on the properties of AlGaN/GaN heterostructures were studied, combining conventional electrical characterization on high-electron mobility transistors (HEMTs), with advanced characterization techniques with nanometer scale resolution, i.e., transmission electron microscopy, atomic force microscopy (AFM) and conductive atomic force microscopy (C-AFM). In particular, a CHF3-based plasma process in the gate region resulted in a shift of the threshold voltage in HEMT devices towards less negative values. Two-dimensional current maps acquired by C-AFM on the sample surface allowed us to monitor the local electrical modifications induced by the plasma fluorine incorporated in the material.The results are compared with a recently introduced gate control processing: the local rapid thermal oxidation process of the AlGaN layer. By this process, a controlled thin oxide layer on surface of AlGaN can be reliably introduced while the resistance of the layer below increase locally.
Synthesis and magnetic properties of single-crystalline Na2-

x
Mn8O16 nanorods
Authors: Lan Changyong , Gong Jiangfeng , Liu Shijiang , Yang Shaoguang 
Published: February 2011

AbstractThe synthesis of single-crystalline hollandite-type manganese oxides Na2-
x
Mn8O16 nanorods by a simple molten salt method is reported for the first time. The nanorods were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and a superconducting quantum interference device magnetometer. The magnetic measurements indicated that the nanorods showed spin glass behavior and exchange bias effect at low temperatures. The low-temperature magnetic behaviors can be explained by the uncompensated spins on the surface of the nanorods.
Expression of sphingosine kinase 1 in amoeboid microglial cells in the corpus callosum of postnatal rats
Authors: Lin Haiyan , Baby Nimmi , Lu Jia , Kaur Charanjit , Zhang Chuansen , Xu Jiajun , Ling Eng-Ang , Dheen S Thameem 
Published: February 2011

AbstractSphingosine kinase 1 (SphK1), a key enzyme responsible for phosphorylating sphingosine into sphingosine-1-phosphate (S1P) has been shown to be expressed in monocytes and monocyte-derived peripheral macrophages. This study demonstrates SphK1 immunoexpression in amoeboid microglial cells (AMC), a nascent monocyte-derived brain macrophage in the corpus callosum of developing rat brain. SphK1 immunofluorescence expression, which appeared to be weak in AMC in normal brain, was markedly induced by lipopolysaccharide (LPS) or hypoxia treatment. Western blot analysis also showed increased expression level of SphK1 in the corpus callosum rich in AMC after LPS treatment. Detection of SphK1 mRNA and its upregulation after LPS treatment was confirmed in primary culture AMC by RT-PCR. Administration of N, N-dimethylsphingosine (DMS), a specific inhibitor of SphK1, effectively reduced upregulated SphK1 immunoexpression in AMC bothin vivoandin vitro. This was corroborated by western blot which showed a decrease in SphK1 protein level of callosal tissue with DMS pretreatment. Remarkably, LPS-induced upregulation of the transcription factor NFκB was suppressed by DMS. We conclude that SphK1 expression in AMC may be linked to regulation of proinflammatory cytokinesviaan NFκB signaling pathway.
Bioinformatic analyses identifies novel protein-coding pharmacogenomic markers associated with paclitaxel sensitivity in NCI60 cancer cell lines
Authors: Eng Lawson , Ibrahim-zada Irada , Jarjanazi Hamdi , Savas Sevtap , Meschian Mehran , Pritchard Kathleen I , Ozcelik Hilmi 
Published: February 2011

Abstract

Background
Paclitaxel is a microtubule-stabilizing drug that has been commonly used in treating cancer. Due to genetic heterogeneity within patient populations, therapeutic response rates often vary. Here we used the NCI60 panel to identify SNPs associated with paclitaxel sensitivity. Using the panel's GI50 response data available from Developmental Therapeutics Program, cell lines were categorized as either sensitive or resistant. PLINK software was used to perform a genome-wide association analysis of the cellular response to paclitaxel with the panel's SNP-genotype data on the Affymetrix 125 k SNP array. FastSNP software helped predict each SNP's potential impact on their gene product. mRNA expression differences between sensitive and resistant cell lines was examined using data from BioGPS. Using Haploview software, we investigated for haplotypes that were more strongly associated with the cellular response to paclitaxel. Ingenuity Pathway Analysis software helped us understand how our identified genes may alter the cellular response to paclitaxel.

Results
43 SNPs were found significantly associated (FDR < 0.005) with paclitaxel response, with 10 belonging to protein-coding genes (CFTR, ROBO1, PTPRD, BTBD12, DCT, SNTG1, SGCD, LPHN2, GRIK1, ZNF607). SNPs in GRIK1, DCT, SGCD and CFTR were predicted to be intronic enhancers, altering gene expression, while SNPs in ZNF607 and BTBD12 cause conservative missense mutations. mRNA expression analysis supported these findings as GRIK1, DCT, SNTG1, SGCD and CFTR showed significantly (p < 0.05) increased expression among sensitive cell lines. Haplotypes found in GRIK1, SGCD, ROBO1, LPHN2, and PTPRD were more strongly associated with response than their individual SNPs.

Conclusions
Our study has taken advantage of available genotypic data and its integration with drug response data obtained from the NCI60 panel. We identified 10 SNPs located within protein-coding genes that were not previously shown to be associated with paclitaxel response. As only five genes showed differential mRNA expression, the remainder would not have been detected solely based on expression data. The identified haplotypes highlight the role of utilizing SNP combinations within genomic loci of interest to improve the risk determination associated with drug response. These genetic variants represent promising biomarkers for predicting paclitaxel response and may play a significant role in the cellular response to paclitaxel.
Larval migration in PERL chambers as an in vitro model for percutaneous infection stimulates feeding in the canine hookworm Ancylostoma caninum
Authors: Franke Daniela , Strube Christina , Epe Christian , Welz Claudia , Schnieder Thomas 
Published: February 2011

Abstract

Background

Ancylostoma caninum third-stage larvae are the non-feeding infective stage of this parasite and are able to infect potential hosts via different infection routes. Since percutaneous infection is one of the most important routes and skin penetration is the first step into parasitic life, an existing in vitro model for percutaneous migration was modified and evaluated. The main parameter used to evaluate migration was the migration ratio (migrated larvae as a percentage of total number of larvae recovered). Additionally, the skin lag was calculated, expressing the percentage of larvae remaining in the skin and therefore not being recovered. Since initiation of feeding is proposed to be an important step in the transition from free-living to parasitic A. caninum larvae, feeding assays were performed with in vitro percutaneously migrated larvae. Additionally, infective larvae of A. caninum were activated via serum-stimulation and feeding behaviour was analysed and compared between percutaneously migrated and serum-stimulated larvae.

Results
Maximum skin migration levels of infective larvae were observed at temperatures above 32°C when larvae were placed on the epidermal side of skin for more than 12 hours. The medium beneath the skin had no effect on migration ratio, and no significant difference between the migration ratios through fresh and frozen/thawed skin was observed.
Maximum feeding levels of 93.2% were observed for percutaneously migrated larvae after 48 h incubation, whereas serum-stimulated larvae reached the maximum of 91.0% feeding larvae after 24 h.

Conclusions
The PERL chamber system was optimised and standardised as an in vitro model for percutaneous migration. The larvae recovered after percutaneous migration showed characteristic signs of activation similar to that of serum-stimulated larvae. The observed difference in time course of resumption of feeding indicates that percutaneously migrated larvae are not identical to serum-stimulated larvae, which are currently representing the model for early parasitic stages.
The combination of the entomopathogenic fungus Metarhizium anisopliae with the insecticide Imidacloprid increases virulence against the dengue vector Aedes aegypti (Diptera: Culicidae)
Authors: Paula Adriano R , Carolino Aline T , Paula Cátia O , Samuels Richard I 
Published: February 2011

Abstract

Background
Dengue fever transmitted by the mosquito Aedes aegypti, is one of the most rapidly spreading insect borne diseases, stimulating the search for alternatives to current control measures. The dengue vector A. aegypti has received less attention than anophelene species, although more than 2.5 billion people are at risk of infection worldwide. Entomopathogenic fungi are emerging as potential candidates for the control of mosquitoes. Here we continue our studies on the pathogenicity of the entomopathogenic fungus Metarhizium anisopliae against adult A. aegypti females. With the aim of further reducing mean survival times of A. aegypti exposed to fungus impregnated surfaces, a sub-lethal concentration of the neonicotinoid insecticide Imidacloprid (IMI) was added to fungal suspensions.

Results
A sub-lethal concentration of IMI that did not significantly alter the daily survival rates or mean survival percentages of mosquitoes was identified to be 0.1 ppm. This sub-lethal concentration was combined with M. anisopliae conidia (1 × 109 conidia mL-1). Both the combined treatment and the conidia alone were able to reduce the survival of A. aegypti compared with untreated or IMI treated mosquitoes. Importantly, mosquito survival following exposure to the combined treatment for 6 and 12 hrs was significantly reduced when compared with mosquitoes exposed to conidia alone.

Conclusions
This is the first time that a combination of an insecticide and an entomopathogenic fungus has been tested against A. aegypti. Firstly, the study showed the potential of IMI as an alternative to the currently employed pyrethroid adulticides. Secondly, as an alternative to applications of high concentrations of chemical insecticides, we suggest that adult A. aegypti could be controlled by surface application of entomopathogenic fungi and that the efficiency of these fungi could be increased by combining the fungi with ultra-low concentrations of insecticides, resulting in higher mortality following relatively short exposure times.
Imprisoned and imperiled: access to HIV and TB prevention and treatment, and denial of human rights, in Zambian prisons
Authors: Todrys Katherine W , Amon Joseph J , Malembeka Godfrey , Clayton Michaela 
Published: February 2011

BackgroundAlthough HIV and tuberculosis (TB) prevalence are high in prisons throughout sub‐Saharan Africa, little research has been conducted on factors related to prevention, testing and treatment services.MethodsTo better understand the relationship between prison conditions, the criminal justice system, and HIV and TB in Zambian prisons, we conducted a mixed‐method study, including: facility assessments and in‐depth interviews with 246 prisoners and 30 prison officers at six Zambian prisons; a review of Zambian legislation and policy governing prisons and the criminal justice system; and 46 key informant interviews with government and non‐governmental organization officials and representatives of international agencies and donors.ResultsThe facility assessments, in‐depth interviews and key informant interviews found serious barriers to HIV and TB prevention and treatment, and extended pre‐trial detention that contributed to overcrowded conditions. Disparities both between prisons and among different categories of prisoners within prisons were noted, with juveniles, women, pre‐trial detainees and immigration detainees significantly less likely to access health services.ConclusionsCurrent conditions and the lack of available medical care in Zambia's prisons violate human rights protections and threaten prisoners' health. In order to protect the health of prisoners, prison‐based health services, linkages to community‐based health care, general prison conditions and failures of the criminal justice system that exacerbate overcrowding must be immediately improved. International donors should work with the Zambian government to support prison and justice system reform and ensure that their provision of funding in such areas as health services respect human rights standards, including non‐discrimination. Human rights protections against torture and cruel, inhuman or degrading treatment, and criminal justice system rights, are essential to curbing the spread of HIV and TB in Zambian prisons, and to achieving broader goals to reduce HIV and TB in Zambia.