Ochratoxin A in pig blood: method of analysis and use as a tool for feed studies

A procedure is presented for screening the quality of feed in respect to ochratoxin A contamination based upon the analysis of ochratoxin A in pig blood. Representative samples from large feed lots may be obtained by using pigs as in vivo sample collectors which enrich the toxin and forms homogeneous samples in the blood. The spectrofluorometric procedure for ochratoxin A analysis (K. Hult and S. Gatenbeck, J. Assoc. Off. Anal. Chem. 59:128-129, 1976) has been adapted to pig blood and has been simplified to involve only three extraction steps. A volume of 2.5 ml of blood or plasma is needed, and the detection limit is 2 ng of ochratoxin A per ml. The disappearance of ochratoxin A from pig blood as a function of time has been studied. A feeding experiment with ochratoxin A has been performed, and the time course of the concentration of ochratoxin A in blood has been followed during the experiment.     

Ochratoxin A in pig blood: method of analysis and use as a tool for feed studies.

A procedure is presented for screening the quality of feed in respect to ochratoxin A contamination based upon the analysis of ochratoxin A in pig blood. Representative samples from large feed lots may be obtained by using pigs as in vivo sample collectors which enrich the toxin and forms homogeneous samples in the blood. The spectrofluorometric procedure for ochratoxin A analysis (K. Hult and S. Gatenbeck, J. Assoc. Off. Anal. Chem. 59:128-129, 1976) has been adapted to pig blood and has been simplified to involve only three extraction steps. A volume of 2.5 ml of blood or plasma is needed, and the detection limit is 2 ng of ochratoxin A per ml. The disappearance of ochratoxin A from pig blood as a function of time has been studied. A feeding experiment with ochratoxin A has been performed, and the time course of the concentration of ochratoxin A in blood has been followed during the experiment.     

Bacteria of the genus Acinetobacter. Their systematics and ecological analysis

The content of A. lwoffi and A. calcoaceticus in water and sewage has been determined. A considerable prevalence of A. lwoffi in both objects has been revealed. The most definite results have been obtained with the use of selective media: ethanol-ammonium medium and Baumann's modified nitrate-acetate medium. The seasonal dynamics of both species in water has been determined, the peak being observed in June and the decrease (and with A. calcoaceticus even disappearance), in August.     

Molecular-genetic organization of plasmid R89S of the incompatibility group Q

A new IncQ plasmid R89S has been analysed by molecular-genetic methods. A restriction map of this plasmid has been constructed and regions of homology with the plasmid RSF1010 have been identified. A genetic map of the plasmid R89S has been prepared based on the deletion and insertion plasmid derivatives. The phenotypic analysis of the derivatives has identified the location of genes coding for replication, incompatibility, mobilization for genetic transfer and resistance to streptomycin in the genome of R89S.     

Saponin Adjuvants. IV. Evaluation of The Adjuvant Quil a in the Vaccination of Cattle Against Foot-And-Mouth Disease

The saponin adjuvant Quil A has been investigated in the vaccination of cattle against foot-and-mouth disease. Using a Frenkel type vaccine a dose-response relationship has been established between Quil A and neutralizing antibody titres. Ten ml of vaccine was combined with 0, 50, 200, 800, and 3200 µg of Quil A. The combinations were each injected into 4 animals. The local reaction on the site of injection produced by injection of the vaccine alone and in combination with different doses of Quil A has been estimated. On this basis a therapeutical dose at 1 mg of Quil A has been estimated to combine maximum adjuvant effect with a minimum of adverse reactions. This dose has been tested in the vaccination of cattle with FMD vaccines derived from BHK suspension cell virus of type O and A respectively. The vaccines were tested in 10 ml and 5 ml doses with or without Quil A, and each in 4 animals. It is concluded that Quil A is a valuable adjuvant for use in the induction of neutralizing antibodies against foot-and-mouth disease in cattle.     

The SPR-based biosensor test system for analysis of small compounds interaction with human cytochrome P450 51A1 (CYP51A1)

The SPR-based test for human cytochrome P450 51A1 (CYP51A1) ligand screening has been developed. Applicability of this system has been validated with known azole inhibitors of cytochromes P450. The studied azoles selectively interacted with human cytochrome P450 51A1, which showed the highest affinity towards ketoconazole. The efficiency of the SPR based assay has been tested using 19 steroid and triterpene compounds, which have not been investigated as potential ligands of CYP51A1.     

Determination of protein A I staphylococcus aureus strains isolated from monkeys

Protein A content in Staphylococcus aureus isolated from 6 species of monkeys at the Sukhumi Monkey Nursery has been studied. Protein A has been detected in 73% of the studied strains. One strain isolated from a rhesus macaque has been found to release high amounts of protein A into the environment.     

A family of repetitive nucleotide sequences (Sau 3A family) in the genome of 2 forms of the sockeye salmon Oncorhynchus nerka

A family of DNA sequences (Sau3A repeat sequences) has been revealed in genomes of two forms of O. nerka. A DNA fragment belonging to this "family" has been cloned in bacterial plasmid. Its copy number (in genomes of normal (570 +/- 33) and dwarf (66 +/- 12) forms) has been counted. The structural organization of sequences of Sau3A family in genomes of males and females of normal form is not the same. The organization of Sau3A sequences is the same in genomes of dwarf males and dwarf females of normal form, but the quantity of Sau3A sequences copies is smaller. It is supposed that the DNA sequences of Sau3A family bear the sex determination of dwarf form of O. nerka. The fragment of rRNA gene of nerka has been cloned and the number of rRNA gene copies in genomes of normal (200 +/- 62) and dwarf (1690 +/- 24) forms has been defined.     

The effect of oligomycin on rat liver mitochondria respiring in state 4

It has been found that oligomycin inhibits up to at least 50% state-4 mitochondrial respiration. A time dependence of oligomycin inhibition has been shown. A titration curve for state-4 respiration of sigmoidal profile has been presented. The possibility of misreading this oligomycin effect, so far never reported, has been excluded by evaluating the quality of mitochondrial preparations used in respect to their morphological, functional and electrochemical properties. The conclusion has therefore been put forward that the most part of respiration in steady-state-4 is driven by ATP synthesis.     

Lipid metabolism indices and their correlation with vitamin D levels in indigenous populations of northern European Russia

The level of 25-OH vitamin D in the blood plasma in indigenous residents of northern European Russia has been studied. Vitamin D deficiency has been shown to be widespread. The lowest prevalence of vitamin D deficiencies (15%) has been found in male reindeer herders; the highest (80–100%) one, in adolescents aged 13–15 years. A significant decrease in the 25-OH vitamin D₃ level has been found in the inhabitants of the Far North in March. A relationship has been found between the serum 25-OH vitamin D concentration and lipid metabolism parameters in residents of the Far North, which is confirmed by significant correlations with the total cholesterol, apolipoprotein A, high- and low-density lipoprotein, and vitamin A and E levels.     

Human placental 17 beta-estradiol dehydrogenase: enzymatic activity in the last weeks of pregnancy and electrophoretic data.

A specific electrophoretic method for human placental 17 beta-estradiol dehydrogenase (17-HSD; EC 1.1.1.62) has been performed and a sample of about 180 placentae from Italian women has been examined. A common phenotype and only one electrophoretic variant have been observed. Also 17-HSD activity has been tested. A statistically significant negative correlation has been found between 17-HSD activity and both gestational age and birth weight in the last weeks of gestation in a group of at term newborns with weight appropriate for date. This reduction in enzymatic activity is in good agreement with the data on estrone and estradiol which both show a declining rate of increase in the last weeks of pregnancy.     

Single-strand and double-strand cleavage at half-modified and fully modified recognition sites for the restriction nucleases Sau3a and Taqi

The influence of cytosine methylation on the cleavage of DNA by the restriction nucleases Sau3A and TaqI has been investigated. Bovine satellite DNA fragments containing a GATCGA sequence, i.e. a Sau3A site overlapping with a TaqI site have been used in this study. The methylation of these fragments has been determined by sequence analysis. It has been found that a TaqI site (TCGA) methylated at cytosine in both DNA strands is still sensitive to double-strand cleavage. A Sau3A site (GATC), however, is rendered resistant to double-strand cleavage by methylation of a single cytosine. Fragments containing the "half-modified" Sau3A site are nicked in the unmethylated DNA strand. It has been shown by sequence analysis of nicked DNA that the single-strand break occurs at the same position which is cleaved in unmodified DNA.     

Immunological study of a hemophiliac treated according to the Bonn protocol for 2 1/2 years

A major haemophiliac A, 27 years old, has been treated during 30 months, with high dosage of imported Factor VIII, in order to reduce the titer of a F VIII antibody. A good clinical result has been obtained. No sign of immunodeficiency has been observed. Normal values were obtained for T4/T8, ratio B2 microglobulin and no antibody was detected against the LAV virus isolated from cases of AIDS.     

Crystallization and preliminary X-ray analysis of flavocytochrome c(3), the fumarate reductase from Shewanella frigidimarina.

The fumarate reductase (flavocytochrome c(3)) from Shewanella frigidimarina (formerly S. putrefaciens) NCIMB400 has been crystallized in the space group P2(1), with cell dimensions of a = 45.447 A, b = 92.107 A, c = 78.311 A, and beta = 91.038 degrees and one molecule per asymmetric unit. A native data set has been collected to 1.8 A. The gene encoding Fcc(3) from the S. frigidimarina type strain ACAM591 has been cloned and sequenced and the protein crystallized in space group P2(1) with cell dimensions of a = 45.359 A, b = 88.051 A, c = 77.473 A, and beta = 104.499 degrees. Anomalous data have also been collected from the NCIMB400 crystal allowing the heme iron positions to be identified.     

A study of conformational states of substrates of cytochrome P450 3A4

A multiconformational study of substrates of cytochrome P450 3A4 has been carried out within the BiS/MC algorithm. The method allowed one to create a pseudoatomic model of the cytochrome and to find the substrate conformers responsible for the interaction with the cytochrome. It has been found that, in most cases, the geometry of the acting conformer is much different from the geometry of the global minimum conformer. It has been shown that the mirror conformational antipodes ("enantioconformers") are characterized as a rule by different Michaelis constants. A quantitative relationship between the Michaelis constants and the parameters of interactions in "model 3A4 isoform-substrate" complexes has been determined. The relationship describes the experimental value of Michaelis constant with the squared cross-validation correlation coefficient of 0.88.     

Genealogical approach to the formation of the winter wheat core collection

The correctness of the genealogical approach to the estimation of genetic diversity has been substantiated. The approach implies a comparison of the estimates of similarity based on genetic markers and coefficients of parentage. A method of the application of the genealogical approach to the formation of the core collection has been developed. The adequacy of the core set has been estimated using Shannon's diversity index adapted for genetic profiles and the correlation between the distributions of ancestors' contributions. A core collection has been formed. This collection contains 25% of the accessions of the original winter wheat (Triticum aestivum L.) collection from the Czech Genebank and represents 70-76% of the intracluster diversity. A decrease in intercluster diversity has not been found in the core collection.     

Alu-like sequences in the regions of replication initiation in plasmids p15A and R6K]

A method of computer analysis of DNA sequences has been proposed. It is based on information similarity of compared sequences and it significantly increases the usefulness of the computer analysis. This approach has been applied to the search of interconnected areas of Alu-repeats and replication origins of p15A and R6K plasmids. An Alu-like region located in the first stem of the secondary structure of RNA-1 and E. coli RNA-polymerase binding site has been found in the p15A. On R6K replication origin, Alu-like repeats have been found in the area of tandem 22 bp repeats. This comparison also allowed to reveal hidden periodicity of the sequence of human Alu-repeat. A hypothesis that explained the data obtained has been proposed. The proposed approach may be used as a method for revealing DNA sequences that have similar genetic functions.     

Genealogical Approach to the Formation of the Winter Wheat Core Collection

The correctness of the genealogical approach to the estimation of genetic diversity has been substantiated. The approach implies a comparison of the estimates of similarity based on genetic markers and coefficients of parentage. A method of the application of the genealogical approach to the formation of the core collection has been developed. The adequacy of the core set has been estimated using Shannon's diversity index adapted for genetic profiles and the correlation between the distributions of ancestors' contributions. A core collection has been formed. This collection contains 25% of the accessions of the entire winter wheat (Triticum aestivum L.) collection from the Czech Genebank and represents 70–76% of the within-cluster diversity. A decrease in between-cluster diversity has not been found in the core collection.     

Extracellular protein A from a methicillin-resistant strain of Staphylococcus aureus

Protein A has been isolated from a methicillin-resistant strain of Staphylococcus aureus, A676, which produces only extracellular protein A. The material is homogeneous after a one-step separation and has a molecular weight of 41000. Its physicochemical and immunochemical properties have been studied.     

Regional distribution of choline acetyltransferase and acetylcholinesterase in rabbit brain

Regional distribution of choline acetyltransferase (CAT) and acetylcholinesterase (AChE) in seventeen regions of the rabbit CNS has been determined by means of the cation exchange radiometric method. A significant correlation has been found between the activities of AChE and CAT which allows computation of their potencies. A comparison between activities of the cholinergic enzymes in the human and rabbit brain has been discussed.