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Acid Extract (acid + extract)
Kinds of Acid Extract Selected AbstractsAbsence of detectable measles virus genome sequence in blood of autistic children who have had their MMR vaccination during the routine childhood immunization schedule of UKJOURNAL OF MEDICAL VIROLOGY, Issue 5 2006M.A. Afzal Abstract Leukocyte preparations from children with documented evidence of MMR vaccination and confirmed diagnosis of autism were examined by several assays designed to target multiple regions of the measles virus genome sequence. No sample was found positive by any method. The assays applied were highly sensitive, specific and robust in nature, and were based on the amplification of measles virus RNA transcripts by real-time quantitative RT-PCR (QRT-PCR) as well as by conventional RT-PCR-nested PCR. The assays applied were potentially able to detect measles virus RNA down to single figure copy numbers per reaction. The amount of total nucleic acid extract of leukocytes subjected to various measles virus-specific investigations was several fold higher than minimally required of a sample where measles virus persistence is well documented. This study failed to substantiate reports of the persistence of measles virus in autistic children with development regression. J. Med. Virol. 78:623,630, 2006. © 2006 Wiley-Liss, Inc. [source] Isolation and characterization of antimicrobial proteins and peptide from chicken liverJOURNAL OF PEPTIDE SCIENCE, Issue 6 2007Guan-Hong Li Abstract Endogenous antimicrobial peptides and proteins are crucial components of the innate immune system and play an essential role in the defense against infection. Antimicrobial activity was detected in the acid extract of livers harvested from healthy adult White Leghorn hens, Gallus gallus. Two antimicrobial proteins and one antimicrobial polypeptide were isolated from the liver extract by cation-exchange and gel filtration chromatography, followed by two-step reverse-phase high-performance liquid chromatography (RP-HPLC). These antimicrobial components were identified as histones H2A and H2B.V, and histone H2B C -terminal fragment using peptide mass fingerprinting and partial sequencing by tandem nanoelectrospray mass spectrometry. The proteins and the peptide identified in the present study, which exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria, were thermostable and showed salt-resistant activity. The antimicrobial properties of histones and histone fragment in chicken provide further evidence that histones, in addition to their role in nucleosome formation, may play an important role in innate host defense against intracellular or extracellular microbe invasion in a wide range of animal species. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd. [source] Cytotoxic activity of an octadecenoic acid extract from Euphorbia kansui (Euphorbiaceae) on human tumour cell strainsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2008Farong Yu We have investigated the cytotoxic and antitumour activity of an octadecenoic acid extract, mainly containing oleic and linoleic acids, from Euphorbia kansui on human gastric (SGC-7901), hepatocellular carcinoma (BEL-7402), and leukaemia (HL-60) tumour cell strains. Significant and dose-dependent antiproliferation effects were observed on tumour cells from the dose of 3.2 ,g mL,1, which were comparable with or better than those of the common antitumour agent 5-fluorouracil. Results from the clone formation assay and flow cytometry indicated that the mixture of octadecenoic acids resulted in a dose-dependent reduction in the number of tumour cells and significantly inhibited cell proliferation, with induced apoptosis and G0/G1 phase cell cycle arrest. Also, the octadecenoic acids could not only cause cell apoptosis/necrosis but also functionally and structurally damage the tumour cell membrane and cell ultra-structures. These observations encourage further clinical evaluation of the inhibitory effects of octadecenoic acids on various forms of cancer. [source] Increased vigabatrin entry into the brain by polysorbate 80 and sodium caprateJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2001D. Dimitrijevic The effects of a non-ionic surfactant, polysorbate 80, and the sodium salt of the saturated fatty acid, sodium caprate (C10), as potential brain absorption enhancers for vigabatrin were studied. Vigabatrin is an enzyme-activated irreversible inhibitor of ,-aminobutyric acid (GABA) transaminase that increases brain and cerebrospinal GABA concentrations in animals and man. Before intravenous administration, a range of concentrations of the surfactants were tested using erythrocyte lysis or the red blood cell lysis test to establish the non-toxic concentration range. Vigabatrin was dissolved in 0.1% polysorbate 80 and 0.1% sodium caprate and administered intravenously in doses of 4 mL kg,1 to male Wistar rats (230,250 g; n = 3). Rats were killed 2 h after drug and surfactant administration and the brains were immediately removed and homogenized in 0.4m perchloric acid. Selected ion monitoring electrospray mass spectrometry was used to determine the concentration of vigabatrin and GABA directly from the perchloric acid extract of the rat brain. This method was developed to increase the speed and efficiency of the analysis by removing the need for complex extraction and derivatization procedures while retaining the specificity of the mass spectrometer as a detector. The stability of both vigabatrin and GABA in perchloric acid was established by monitoring their pseudo molecular ions in standard solutions at timed intervals over 24 h. Although the detection level for vigabatrin and GABA was at least 50 pg, only GABA was detected in rat brain. Vigabatrin caused a small increase in whole brain GABA. However, GABA levels were higher in the samples with vigabatrin + enhancer than in the samples where vigabatrin alone was administered. One-way analysis of variance indicated a significant effect of the surfactants on GABA levels (F (5,17) = 11.86, P < 0.01) and vigabatrin absorption was presumed. The rectal temperature of the rats is lowered by the presence of vigabatrin in the brain. Vigabatrin alone decreased rectal temperature by 6%. When given with either polysorbate 80 or sodium caprate, the extent of temperature lowering was significantly greater (P < 0.001). There was no significant difference after 2 h between polysorbate 80 + vigabatrin, and sodium caprate + vigabatrin. [source] Brain GABA editing by localized in vivo1H magnetic resonance spectroscopyNMR IN BIOMEDICINE, Issue 2 2004G. Bielicki Abstract Editing of GABA by 1H MRS in a specific brain area is a unique tool for in vivo non-invasive investigation of neurotransmission disorders. Selective GABA detection is achieved using sequences based on double quantum coherence (DQC). Our pulse sequence makes accurate measurements without artefacts due to spatial localization. The sequence was tested on a phantom solution. The effect of vigabatrin, a specific inhibitor of GABA transaminase, was measured in rat brain and GABA detection was performed in vivo in monkey brain using this procedure. Rats were spilt into two groups. In the control group, the rats had access to water and, in the other group (vigabatrin, VGB, rats), animals were allowed free access to drinking water containing vigabatrin. After 3 weeks of treatment, rats were anesthetized for in vivo NMR spectroscopy investigation. At the end of the experiment, brains were quickly removed, freeze-clamped and extracted with 4% perchloric acid. One part of the acid extract was used for GABA concentrations assessment by ion exchange chromatography with ninhydrin detection. The second was used for high-resolution NMR analysis. By chromatography measurements, the GABA concentration was 1.23±0.06,,mol/g for controls, while for vigabatrin-treated rats the GABA concentration was 4.89±1.60,,mol/g. The NMR in vivo results were closely correlated with the NMR ex vivo (r=0.99, p<0.01) and chromatography results (r=0.98, p<0.01). The correlation between ex vivo results and chromatography results was also high (r=0.99, p<0.001). This pulse sequence performed GABA editing from a 376,,l voxel located on the right basal ganglia area in a non-human primate brain. This in vivo GABA editing scheme can thus be proposed for accurate measurement of brain GABA concentrations. Copyright © 2004 John Wiley & Sons, Ltd. [source] The turnover of the H3 deuterons from (2- 13C) glutamate and (2- 13C) glutamine reveals subcellular trafficking in the brain of partially deuterated ratsJOURNAL OF NEUROCHEMISTRY, Issue 2009Sebastián Cerdán Abstract We investigated by 13C NMR the turnover of the H3 deuterons of (2- 13C) glutamate and (2- 13C) glutamine in the brain of partially deuterated rats. Adult animals (150,200 g) fed ad libitum received 50%2H2O or tap water 9 days before infusing (1- 13C) glucose or (2- 13C) acetate for 5, 10, 15, 30, 60, or 90 min. The brains were then funnel-frozen and acid extracts were prepared and analyzed by high-resolution 13C NMR. The deuteration of one or the two H3 hydrogens of (2- 13C) glutamate or glutamine resulted in single (,0.07 ppm) or double (,0.14 ppm) isotopic shifts upfield of the corresponding C2 perprotonated resonance, demonstrating two sequential deuteration steps. The faster monodeuteration generated 3R or 3S (2- 13C, 3- 2H) glutamate or glutamine through the alternate activities of cerebral aconitase or isocitrate dehydrogenase, respectively. The slower process produced bideuterated (2- 13C, 3,3,- 2H2) glutamate or glutamine through the consecutive activity of both enzymes. The kinetics of deuteration was fitted to a Michaelis,Menten model including the apparent Km, and Vmax, values for the observed deuterations. Our results revealed different kinetic constants for the alternate and consecutive deuterations, suggesting that these processes were caused by the different cytosolic or mitochondrial isoforms of aconitase and isocitrate dehydrogenase, respectively. The deuterations of (2- 13C) glutamate or glutamine followed also different kinetics from (1- 13C) glucose or (2- 13C) acetate, revealing distinct deuteration environments in the neuronal or glial compartments. [source] In vitro1H magnetic resonance spectroscopy differences between meningeoma and astrocytomaJOURNAL OF NEUROCHEMISTRY, Issue 2003K. Likav, anová Tumor transformation of the human brain cells causes different biochemical changes. Here we employed 1H magnetic resonance spectroscopy to compare the presence of low molecular weight metabolites in meningeoma and astrocytoma tumors by measuring perchloric acid extracts of the cells. In 1H spectra of meningeoma we detected high signal from lactate but were unable to detect any signal of NAA and creatine. In contrast, astrocytoma samples revealed significantly higher level of inositol and glycine and significant decrease in glutamate and glutamine compared with meningeoma but no presence of taurine. Our results suggest that 1H MRS can provide useful information about biochemical changes in different types of brain tumors. Acknowledgements: This work was supported by the Grant Category C and Comenius University Grant No. X/2003. [source] Sensitive and Specific Digoxigenin-labelled RNA Probes for Routine Detection of Citrus tristeza virus by Dot-blot HybridizationJOURNAL OF PHYTOPATHOLOGY, Issue 6 2006L. Barbarossa Abstract A non-radioactive dot-blot hybridization assay for the successful detection of Citrus tristeza virus (CTV) RNA in total nucleic acid extracts of infected citrus was developed. Two digoxigenin (DIG)-labelled minus-sense riboprobes, complementary to the coat protein gene sequence of a Chinese and an Apulian CTV isolate were synthesized. Several citrus tissues were evaluated as optimal virus source and leaf petioles were found appropriate material for reliable detection. The hybridization assay showed a detection limit corresponding to 0.2 mg of fresh infected tissue. The riboprobes allowed CTV detection in isolates from different geographical areas, grown in the screenhouse or in the field, resulting in similar hybridization patterns. The infected trees were tested during different seasons with positive results, although from July to August most of the samples gave a weaker hybridization signal, compared to other seasons. The high sensitivity and reliability of the molecular hybridization assay described make it a good alternative to serological methods for CTV detection. [source] The effect of experimental conditions on the detection of spermine in cell extracts and tissuesNMR IN BIOMEDICINE, Issue 2 2010Nicholas G. Spencer Abstract The aim of this work was to investigate the effect of experimental conditions on the visibility of polyamines. In solution the chemical shift of the three groups of peaks (at approximately 1.8, 2.1 and 3.1,ppm) were found to be pH dependent. Relaxation times in aqueous solution at pH 7.0, 298,K and 11.74,T were measured to be: putrescine (T1,=,2.49,s, T2,=,2.07,s), spermidine (T1,=,1.27,s, T2,=,1.05,s) and spermine (T1,=,1.02,s, T2,=,0.82,s). Simple spin-echo sequences could not be used to measure T2 as the spins also experience phase evolution from homonuclear coupling which imposes a modulation on the T2 decay curve. This modulation is eliminated by using CPMG sequences with an echo spacing of <500,µs. Relaxation times for spermine in solution in presence of metal ions and protein showed that metal ions had little effect on T2; however, addition of 15,mg/ml bovine serum albumin reduced T2 of spermine (0.41,s at 298,K and 0.19,s at 277,K) but was not as short as the T2 of the polyamine peak in prostatic tissue (0.03,s at 277,K). The MR visibility of polyamines in prostate cell extracts, PC-3 xenograft (intact as well as extracted) and intact human prostatic tissues were investigated. Polyamines were not detected in methanol/chloroform extracts, but were visible in perchloric acid extracts of prostate tumour cells. No polyamines were detected in the HR MAS spectra of three samples of whole PC-3 xenograft tissue studied. In summary, the chemical shift of polyamine species is pH dependent, while protein binding causes peak broadening and reduction in T2. Perchloric acid extraction improves visibility of intracellular polyamines, but whole tissue polyamines are not seen in xenografts without epithelial/ ductal structure. Copyright © 2009 John Wiley & Sons, Ltd. [source] High-resolution magic angle spinning MRS of breast cancer tissueNMR IN BIOMEDICINE, Issue 5 2002Beathe Sitter Abstract High-resolution magic angle spinning (HR MAS) may develop into a new diagnostic tool for studying intact tissue samples, and several types of cancer have been investigated with promising results. In this study HR MAS spectra of breast cancer tissue from 10 patients have been compared to conventional high-resolution spectra of perchloric acid extracts of the same tissue type. The HR MAS spectra show resolution comparable to spectra of extracts, and two-dimensional techniques lead to identification of a majority of the constituents. More than 30 different metabolites have been detected and assigned. To our knowledge this is the most detailed assignment of biochemical components in intact human breast tissue. The spectra of intact breast cancer tissue differ from perchloric acid extracts by the presence of lipids and fewer signals in the low field region. HR MAS analysis of intact breast tissue specimens is a rapid method, providing spectra with resolution where relative quantification of the majority of the detected metabolites is possible. Copyright © 2002 John Wiley & Sons, Ltd. [source] | |||||||||||||