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PubMed2001

Recombinant expression of perchloric acid-soluble protein reduces cell proliferation.

Perchloric acid-soluble protein (PSP) may play an important role in the regulation of cellular physiological functions because it has been highly conserved throughout evolution; however, this role has not been well elucidated. In previous reports, we suggested that PSP regulates cell proliferation. In this study, we examined the effect of PSP expression on proliferation of the normal rat kidney cell line NRK-52E, the rat hepatocyte cell line RLN-10, and the rat hepatoma cell line dRLh-84. Cells transfected with pcDNA-sense-PSP (pcDNA-S-PSP) over-expressed PSP mRNA and protein, and cell proliferation of the transfected cells was suppressed compared with that of cells transfected with pcDNA-empty (pcDNA-E). Cell viability of pcDNA-S-PSP-transfected cells was similar to that of pcDNA-E-transfected cells. Thus, over-expression of PSP suppresses cell proliferation without any influence on cell viability. These findings are the first to report an inhibitory activity of PSP on cell proliferation.

Animals↗

PubMed1999

Ribonuclease activity of rat liver perchloric acid-soluble protein, a potent inhibitor of protein synthesis.

Rat liver perchloric acid-soluble protein (L-PSP) is a potent inhibitor of cell-free protein synthesis; however, its mechanism of action is not known. Here we show that the protein is a unique ribonuclease and that this activity is responsible for the inhibition of translation. The addition of perchloric acid-soluble protein to a rabbit reticulocyte cell-free system at a concentration of 6.2 microM led to an almost complete inhibition of protein synthesis. The kinetics are unlike those of hemin-controlled inhibitor, a protein that acts at the initiation step. The inhibition appears to be due to an endoribonucleolytic activity of perchloric acid-soluble protein because L-PSP directly affects mRNA template activity and induces disaggregation of the reticulocyte polysomes into 80 S ribosomes, even in the presence of cycloheximide. These effects were observed with authentic as well as recombinant L-PSP. Analysis by thin-layer chromatography of [alpha-32P]UTP-labeled mRNA incubated with the protein showed production of the ribonucleoside 3'-monophosphates Ap, Gp, Up, and Cp, providing direct evidence that the protein is an endoribonuclease. When either 5'- or 3'-32P-labeled 5 S rRNA was the substrate, L-PSP cleaved phosphodiester bonds only in the single-stranded regions of the molecule.

Animals↗

PubMed1993

[Serological property of perchloric acid-soluble glycoprotein fractions of human meconium].

Perchloric acid-soluble fractions (PASFs) were separated, in yields of 87.0-151.9 mg per 1.0 g of wet meconium sample, from six samples of human meconium, and identified as glycoproteins having 41.2-74.1% carbohydrate by chemical composition analysis. Six PASFs reacted with anti-A, -B, -Lea and -Leb sera, but did not react with anti-M and -N sera. These PASFs alos reacted with many lectins such as DBA, UEA-I, Vicia graminea lectin (VGA), Vicia unijuga lectin (VUA), Con A, WGA, RCA-I, PHA-E, SBA, SJA, and influenza A and B viruses. The serological results show that six PASFs contained VGA or VUA-binding (Vgu) glycoproteins as new oncofetal substances, but did not contain M and N blood group substances.

Amino Acids↗

PubMed2004

Evaluating heavy metal contents in nine composts using four digestion methods.

The production and application of compost potentially contaminate the environment with heavy metals. The heavy metal contents of composts must be exactly determined. Therefore, this study aims to understand the heavy metal contents in composts, using different digestion methods and to recommend the most appropriate digestion method making this measurement. Nine composts from different sources, including swine manure, poultry litter, food waste, municipal sewage sludge, soybean meal, wood residues, flesh-bone dust, fish-bone meal and guano, were selected to be digested by four methods to determine the contents of Cd, Cr, Cu, Mn, Ni, Pb and Zn by AAS. The four digestion methods were nitric acid, dry ashing, nitric-perchloric acid and sulfuric acid methods. Analytical results indicated that the nitric acid procedure was the most efficient for recovering Cd, Mn and Ni from most compost samples. The sulfuric acid procedure yielded the lowest recovery of Pb from the certified reference material (BCR 146) and the compost samples, especially from the composts with high pH and EC values potentially high in Ca. The nitric acid procedure was recommended as the method for digesting the composts herein, based on recovery analysis, cost and time taken. Dry ashing was recommended as a flexible method. Nitric-perchloric acid procedure was not recommended because perchloric acid is potentially hazardous during digestion and it recovers relatively little heavy metal.

Chemistry Techniques, Analytical↗

PubMed2006

Comparative determination of halofantrine tablets by titrimetry, spectrophotometry and liquid chromatography.

Comparative determination of halofantrine tablets by titrimetry, ultraviolet spectrophotometry and liquid chromatography (LC) is described. Non-aqueous titrimetry on halofantrine hydrochloride tablets was carried out using glacial acetic acid as solvent, perchloric acid as titrant and crystal violet as indicator. Simultaneous potentiometric monitoring of end point delineated an exact color shade of indicator at the end point. Direct measurement of methanol solution, at 254 nm, was adopted for UV spectrophotometric method while reversed-phase liquid chromatographic (LC) method employed a C8 column (4.6 mm x 25 cm) with mobile phase consisting of methanol / 0.05 M NaH2PO4 (76:24, v/v) containing 55 mmol/L perchloric acid (pH 3.4) at a flow rate of 1 ml / min. The three methods gave precise and accurate results. Mean percentage recovery were obtained respectively as 100.73 +/- 0.41, 100.36 +/- 0.79 and 99.93 +/- 3.74% while coefficient of variation were 0.41, 1.36 and 3.74% for non-aqueous. UV spectrophotometry and LC. The three methods were successfully applied to analysis of halofantrine tablets (Halfan) and showed no statistically significant difference in accuracy (P > 0.05, ANOVA). Validated assay methods for halofantrine tablets have been developed. The titrimetric and spectrophotometric methods are of equivalent accuracy with the liquid chromatographic method and could be used for routine quality control of halofantrine tablets where LC method is not readily available.

Antimalarials↗

PubMed1995

Plasma level determination of 1,4-butanedisulphonate by ion chromatography and conductimetric detection.

A rapid, specific and reproducible liquid chromatographic method was developed for the determination of 1,4-butanedisulphonate in plasma. The method involves protein precipitation with perchloric acid, precipitation of perchlorate ions by addition of potassium carbonate followed by ion chromatography on an ion-exchange column connected with a conductimetric detector. Calibration graphs were linear over the concentration range 2.5-25 micrograms/ml; the intra-assay precision was < or equal to 3.6% and the inter-assay precision was < or equal to 5.8%. The analyte was stable in plasma and in perchloric acid at 37 degrees C for 24 h. The assay procedure was applied to monitoring plasma levels in animals receiving chronic intravenous and oral administration of the analyte.

Alkanesulfonates↗

PubMed2005

Nuclear transfer of perchloric acid-soluble protein by endoplasmic reticulum stressors.

Perchloric acid-soluble protein (PSP) is highly conserved during evolution from bacteria to mammals. Although PSP has been recognized as an inhibitor of translation and proliferation in vitro, its precise biological role has not yet been elucidated. Since we previously found similar distributions for PSP and the endoplasmic reticulum (ER) and Golgi complex, the intracellular distribution of PSP was analyzed in more detail. Immunofluorescence studies indicated that PSP co-localized with the ER and Golgi complex, since the distribution pattern of PSP was well matched to both of these organelles. An immunoelectron microscopic study revealed PSP was located not only in the cytosol but also on the surface of the outer ER membrane. Since PSP was present on the ER, we speculated that it may be associated with ER function. Therefore, we analyzed whether or not the ER stress response, which is one of the ER functions, affected PSP expression. The results showed that various ER stressors (thapsigargin, A23187, tunicamycin, brefeldin A, and cisplatin) provoked a dramatic change in the localization of PSP from outside of the nucleus to inside the nucleus within 3 h. Moreover, the ER stressors induced PSP expression. These results suggest that PSP is involved in the cellular response to ER stressors, and that the change in localization of PSP from the ER to the nucleus may be associated with ER stress responses.

Active Transport, Cell Nucleus↗

PubMed1995

Analysis of ethanol and acetaldehyde recovery from perchloric acid-treated blood.

Recovery of acetaldehyde (0-20 microM) or ethanol (0-50 mM) added to blood and subsequently treated with perchloric acid (PCA) was evaluated using head-space gas chromatography and compared with controls. Using blood from five dogs, < 100% of acetaldehyde and ethanol was recovered from PCA-treated samples. Mathematical models of putative binding mechanisms indicated acetaldehyde partitioned simply between supernatant and PCA-induced precipitate and occupied < 1% of acetaldehyde binding sites on precipitate; ethanol partitioned simply between supernatant and precipitate and occupied > 62% of ethanol binding sites. The mathematical model also indicated acetaldehyde binding is 2500-fold stronger than ethanol binding. These results indicate as much as 46.4% of acetaldehyde may be bound to PCA-induced precipitate formed in whole blood. This loss of acetaldehyde is 3- to 4-fold greater than acetaldehyde loss caused by evaporation from PCA-treated blood.

Acetaldehyde↗

PubMed1987

A direct determination of taurine in perchloric acid-deproteinized biological samples.

A high-performance liquid chromatographic method was developed to estimate the amount of taurine in tissue extracts and body fluids. Shodex Ionpak C-811, an adsorption-distribution type column, was chosen and combined with 3 mM perchloric acid as the mobile phase. The eluted taurine was derivatized with o-phthaladehyde-2-mercaptoethanol reagent and measured at an absorbance of 350 nm instead of fluorescent intensity. Using this method, it was possible to isolate and estimate the amount of taurine from other coexisting substances or structural analogs such as hypotaurine, cysteamine, or cysteinesulfinic acid. For rapid routine assays of taurine in many biological samples, it is advisable that the tissue extracts be pretreated with cation-exchange resin to exclude other interfering substances including O-phosphoserine. The linear relationship between the concentration of taurine and absorbance achieved over the concentration range 0.1-10.0 nmol and the recoveries obtained were 98-101% by the internal standard method. The specificity, reproducibility, and sensitivity of this method for taurine were good enough to be used for biological applications. Examples of the tissue levels of taurine in various organs of the rat, as determined by this new method, are also presented.

Animals↗

PubMed1987

A procedure for measuring peptides in rumen fluid and evidence that peptide uptake can be a rate-limiting step in ruminal protein degradation.

A relatively simple and sensitive procedure was developed to measure the concentration of peptides in rumen fluid. Feed particles and microorganisms were removed by centrifugation, and the supernatant was treated with perchloric acid (5% final concentration). Perchloric acid precipitated macromolecules that included protein, RNA, and DNA. Perchlorate was subsequently removed by precipitation with an excess of potassium carbonate. Ammonia was removed by boiling the alkaline sample. Supernatant samples were then analyzed for ninhydrin reactive material before and after HCl hydrolysis. Because ninhydrin reaction was 3 to 7.5 times greater after HCl hydrolysis, peptides rather than amino acids were the primary source of nonprotein, nonammonia nitrogen. Rumen fluid from a cow fed timothy hay and concentrate supplement (16% crude protein) contained more than 1200 mg peptides/L (192 mg N/L), 1 h after feeding, and this value declined the prefeeding value of 400 mg/L (64 mg N/L) by 8 h after feeding. Comparison of ninhydrin reactivity with and without HCl hydrolysis indicated that peptides present before feeding contained more peptide bonds than the peptides soon after feeding. High pressure liquid chromatography revealed a variety of peaks soon after feeding and fewer dominant peaks 8 h later. The data suggest that peptide uptake into rumen microorganisms can be a rate-limiting step in ruminal protein degradation.

Animals↗

PubMed2003

Determination of trace levels of haloacetic acids and perchlorate in drinking water by ion chromatography with direct injection.

Disinfection by products of haloacetic acids and perchlorate pose significant health risks, even at low microg/l levels in drinking water. A new method for the simultaneous determination of nine haloacetic acids (HAAs) and perchlorate as well as some common anions in one run with ion chromatography was developed. The HAAs tested included mono-, di-, trichloroacetic acids, mono, di-, tribromoacetic acids, bromochloroacetic acid, dibromochloroacetic acid, and bromodichloroacetic acid. Two high-capacity anion-exchange columns, a carbonate-selective column and a hydroxide-selective hydrophilic one, were used for the investigation. With the carbonate-selective column, the nine HAAs as well as fluoride, chloride, nitrite, nitrate, phosphate and sulfate could be well separated and determined in one run. With the very hydrophilic column and a gradient elution of sodium hydroxide, methanol and deionized water, the nine HAAs, fluoride, chloride, nitrite, nitrate as well as perchlorate could be simultaneously determined in one run within 34 min. The detection limits for HAAs were between 1.11 and 9.32 microg/l. For perchlorate, it was 0.60 microg/l.

Acetates↗

PubMed2003

Comparison of microdialysis and push-pull perfusion for retrieval of serotonin and norepinephrine in the spinal cord dorsal horn.

Both push-pull and microdialysis methods are utilized to measure norepinephrine and serotonin in the dorsal horn of the spinal cord. This experiment was designed to determine which technique is better for measurement of norepinephrine and serotonin in the spinal cord and also to determine if the samples are best collected with or without perchloric acid. Sample stability and an assay validation for precision, limit of quantification, and limit of detection were also performed. Push-pull or microdialysis catheters were placed transversely through the dorsal horn and the catheter was perfused with artificial cerebrospinal fluid. Noxious pinch (20 s/min for 10 min) was used to evoke a change in the concentration of catecholamines. Samples were collected before, during and after pinch. No basal concentrations of epinephrine and serotonin were found with microdialysis. Although basal concentrations of norepinephrine were measured by microdialysis, there was no change in response to noxious pinch. The push-pull technique coupled with collection of samples without perchloric acid showed that significant increases in serotonin and norepinephrine are measurable in response to noxious pinch. In contrast, when samples were collected with perchloric acid present there was no change in serotonin or norepinephrine in response to pinch. The stability of catecholamines is greatly affected by perchloric acid such that there is a near complete loss of ability to detect serotonin and norepinephrine by 24 h in samples collected by push-pull. In contrast, samples collected without perchloric acid showed only a 20% reduction in concentration by 24 h. Even without perchloric acid, by 1 wk there was a 50% or greater loss in the concentrations of norepinephrine in push-pull samples. Thus, to measure changes in catecholamines in the dorsal horn, push-pull collected without perchloric provides measurable, reliable and valid results if analyzed by high performance liquid chromatography within 24 h.

Animals↗

PubMed1990

Determination of selenium in blood plasma and serum by flow injection hydride generation atomic absorption spectrometry.

A flow injection hydride generation atomic absorption spectrometric (AAS) method has been used to determine the selenium concentrations of human serum and plasma samples following digestion with nitric, sulphuric and perchloric acids. In the hydride generation process, reduction was carried out by sodium tetrahydroborate to produce a hydride that was atomized in a flame-heated atomisation cell. The method had a detection limit of 1.2 ng ml-1 and a sensitivity of 2.1 ng ml-1. Within-run precisions of 5.8% at 20 ng ml-1 and 4.5% at 80 ng ml-1, and between-run precisions of 4.8% at 69 ng ml-1 and 3.4% at 80 ng ml-1 were obtained. An inter-laboratory comparison study with a graphite furnace AAS method was carried out and the results showed excellent agreement. The flow injection method of sample introduction allowed the use of a sample volume of 330 microliters with an injection rate of 90 injections per hour.

Borohydrides↗

PubMedDate not supplied

Determination of selenium in meat products by hydride generation atomic absorption spectrophotometry.

Wet digestion using a mixture of nitric, sulfuric, and perchloric acids and an aluminum block digester effectively and rapidly decomposed meat samples for selenium determination by hydride generation atomic absorption spectrophotometry. Digestion did not require constant attention by an operator. Selenium recoveries (range, 94-105%) from National Institute of Standards and Technology standard reference materials and spiked samples were used to validate method accuracy. Coefficients of variation (CVs) of repeatability of in-house reference materials used for precision study were 6.4 and 5.6%, respectively, for seafood mix and mutton liver. Selenium levels in meat products from Brisbane markets varied widely: 0.042-0.142, 0.081-0.42, and 0.050-0.198 microgram/g (wet weight) respectively, for beef, chicken, and pork. Overall, selenium levels in manufactured meat ranged from 0.041 to 0.189 microgram/g. The levels of selenium found in this study were generally lower than those reported in Finland but comparable with those reported in some parts of the United States.

Animals↗

PubMed2002

A convenient one-step extraction of cellular ATP using boiling water for the luciferin-luciferase assay of ATP.

Cellular ATP is commonly determined as production of bioluminescence using a luciferin-luciferase reaction system. Before the measurement of bioluminescence, cellular ATP must first be extracted. Two commonly used extraction methods are: () Tris-borate buffer (pH 9.2) coupled with a heating process (to inactivate ATPase) and () perchloric acid followed by neutralization. However, we found that both Tris-borate buffer and perchloric acid interfered with the luciferin-luciferase system. Here, we report a convenient single-step boiling deionized water (DW) method for extracting cellular ATP to replace perchloric acid and Tris-borate buffer. We showed that the boiling DW method did not interfere with the bioluminescence and was effective in inhibiting ATPase. This improved method required no neutralization and dilution and thus was more convenient than the perchloric acid method. Unlike the Tris-borate/heating procedure, our method did not require a separate heating step because boiling DW effectively inhibited ATPase and thus accomplished the two missions in one step for both suspended and attached cells. The improved method was precise for both suspended cells and attached cells, when cell numbers were between 10(3) and 10(6). The method also was more sensitive than other methods because it required much fewer cells (10(4) to 10(5)) than other methods for ATP determination. Thus, this one-step method is suitable for routine assay of cellular ATP for both suspended and attached cells.

Adenosine Triphosphate↗

PubMed1987

Monoclonal antibody against carcinoembryonic antigen (CEA) identifies two new forms of crossreacting antigens of molecular weight 90,000 and 160,000 in normal granulocytes.

Two new forms of non-specific crossreacting antigens (NCAs) were identified in the Nonidet P40 (NP-40) extracts of normal granulocytes by precipitation with the monoclonal antibody (MAb) 192 directed against carcinoembryonic antigen (CEA) and already known to crossreact with the perchloric acid soluble NCA-55. The NP-40 soluble NCAs recognized by MAb 192 have apparent mol. wts of 90,000 and 160,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Both NCAs appear to consist of a single monomeric polypeptide chain, since they have the same electrophoretic mobility in SDS-PAGE under reduced and non-reduced conditions. When granulocytes were extracted with perchloric acid instead of NP-40, only the 55,000 mol. wt antigen, corresponding to the previously described NCA-55, was precipitated by MAb 192. Furthermore, it was shown that NCA-55 is not a degradation product of NCA-90 or NCA-160 due to the perchloric acid treatment because exposure to perchloric acid of NCA preparations purified from NP-40 extracts did not change their apparent mol. wts in SDS-PAGE. It was also shown that NCA-160 is not a granulocytic form of CEA because it was not precipitated by the MAb 35 reacting exclusively with CEA. Immunocytochemical studies of granulocytes and macrophages showed that MAb 192 stained both types of cells whereas MAb 47 stained only the granulocytes and MAb 35 none of these cells. In granulocytes both MAbs reacted with antigens associated with granules and also present at the periphery of the nucleus as well as in the Golgi apparatus. The NCA-90 identified by MAb 192 was found by sequential immunodepletion to be antigenically distinct from the NCA-95 precipitated by MAb 47. The epitope recognized by MAb 192 on CEA and NCA molecules appears to be on the peptidic moiety because the antigens deglycosylated by the enzyme Endo F were still precipitated by this MAb. Taken together, the results indicate that MAb 192 identifies two novel forms of NCA (NCA-90 and NCA-160) in NP-40 extracts of granulocytes, which are distinct from CEA and the previously described NCA-55 and NCA-95 identified by MAbs 192 and 47, respectively, in perchloric acid extracts of granulocytes.

Antibodies, Monoclonal↗

PubMed2005

Energetic quaternary salts containing bi(1,2,4-triazoles).

New energetic salts (2, 3, 9, 10, and 11) were synthesized via the protonation of 4,4'-bi(1,2,4-triazole) or N-4-(1,2,4-triazole)-N-3-(4-methyl-1,2,4-triazole)amine with nitric acid or perchloric acid or 5-nitro-tetrazole. The structures of 4,4'-bi(1,2,4-triazolium) nitrate (2), N,N-dimethyl-N'-(5-methyl-tetrazole)methanimidamide (8), and N-4-(1,2,4-triazole)-N-3-(4-methyl-1,2,4-triazolium)amine perchlorate (10) were confirmed by a single-crystal X-ray analysis. The physical properties and heats of combustion of the new ionic salts were measured, and the heats of formation were also determined.

Journal Article↗

PubMed1992

Identification and characterization of new antigenic fragments related to carcinoembryonic antigen in adult feces.

Antigens in human adult feces related to carcinoembryonic antigen (CEA) were analyzed with respect to their molecular masses, CEA domain compositions, and N-terminal amino acid sequences. By avoiding perchloric acid treatment, new fecal antigens related to CEA were identified. The fecal antigens revealed by Western blot were M(r) 78,000, 70,000, 60,000, 50,000, 44,000, 36,000, 33,000, and 25,000 and a species M(r) less than or equal to 14,000. Unlike native CEA, all of the fecal antigens were very poorly soluble in perchloric acid and did not bind to concanavalin A, suggesting that they had undergone significant deglycosylation in the digestive tract. The major fecal antigens were purified by immunoaffinity chromatography and their N-terminal amino acid sequences determined. FA78, FA60, FA33, and the M(r) less than or equal to 14,000 antigen had the N-terminal amino acid sequence of the CEA N-domain, and FA44 and FA25, the sequence of the CEA A2 domain. The CEA domain compositions of the fecal antigens were investigated by probing them with anti-CEA monoclonal antibodies of known domain specificities. The N-terminal amino acid sequences, immunoreactivities with anti-CEA monoclonal antibodies, and apparent molecular masses of the fecal antigens allowed the following domain assignments (based on CEA as N-A1B1-A2B2-A3B3): FA78, N-A1B1-A2B2-A3B3; FA60, N-A1B1-A2B2; FA44, A2B2-A3B3; FA33, N-A1B1; and FA25, A2B2. The M(r) less than or equal to 14,000 antigen was shown to be the N-domain of CEA or nonspecific cross-reacting antigen. FA36 was assigned the N-AB domain structure of nonspecific cross-reacting antigen. The results suggested that FA78, FA60, FA44, FA33, and FA25 were degradation products (including deglycosylation and proteolysis) of CEA and that FA36 was a degradation product of nonspecific cross-reacting antigen.

Adult↗