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C Gaillard

Publications and source records attributed to C Gaillard.

At least 127 records · Page 7Linked to original sources
PubMed1983

Genomic environment of variant surface antigen genes of Trypanosoma equiperdum.

Expression of variant antigen genes in Trypanosoma equiperdum is accompanied by the duplication of a silent basic copy gene and the transposition of the copy to an expression site elsewhere in the genome. We have analyzed the genomic locations of both the basic and expression-linked copies of the T. equiperdum gene for variable surface glycoprotein VSG-1. Both copies are situated proximal to termini in both extracted DNA and in chromatin. The regions between the VSG-1 genes and the termini have a very high buoyant density in CsCl and contain an unidentified nucleoside that replaces deoxycytidine.

Animals↗
PubMed1983

[A study of pharmacokinetics of cefoperazone in children].

A study of the pharmacokinetics of cefoperazone (CPZ), used as the sole antibiotic, was performed in 17 children and neonates. The types of infections treated were 7 UTI, 2 otitis media, 2 RTI, 4 septicemia or severe neonatal infections. Causative bacteria included 6 E. coli, 3 Pseudomonas aeruginosa, 1 C perfringens, 1 Klebsiella pneumoniae and 2 Staphylococcus aureus. Cefoperazone was administered by means of rapid IV injections (over 5 min) or IV infusions BID. The blood samples were taken by means of capillary microtubes at time 0, 0.25, 0.50, 0.75, 1, 2, 4, 6, 8 and 12 hours after the end of the first injection. After centrifugation and freezing at -80 degrees DEG method using modified Difco M2 Agar (Nall plus sodium citrate) and stock organinism Bacillus subtilis Atcc 6633. The results achieved in children and neonates were compared, in the 11 children (mean age 6.5 years). The mean single dose was 53 mg/kg. The mean maxima concentration was 145 mcg/ml and was obtained at 0.5 h. Mean serum half-life is 2.4 h. For the neonates mean age was 16 days and the dosage was 47 mg/kg, the maxima concentration was 232 micrograms/ml and was obtained at 0.6 h. The mean serum half-life was 3.4 h in the 2 groups, serum levels at 12 h were still high with a mean of 6.2 micrograms/ml for the 17 children. It appears that doses of 25-50 mg/kg given BID would be satisfactory.

Adolescent↗
PubMed1983

Comparison of the metabolism of oltipraz in the mouse, rat and monkey and in man. Distribution of the metabolites in each species.

4-Methyl-5-(2-pyrazinyl)-1,2-dithiole-3-thione (35 972 R.P., oltipraz) and its metabolites were extracted from human urine and from mouse, rat and monkey urine using Amberlite XAD4 resin. The metabolites were identified by GLC, TLC and HPLC and isolated by preparative TLC or HPLC. The structures of 11 compounds were determined by spectroscopic examination (MS, IR, NMR). Six of the principal metabolites isolated in sufficient quantity from human urine were administered to the mouse, confirming the metabolic pathways of oltipraz.

Acetylation↗
PubMed1982

Thawing time and nonreturn rate of bovine semen frozen in fine French straws.

Bovine semen packaged in fine French straws was thawed for 8 or 25 s in warm water baths (38 +/- 2 degrees C). During 12 months, 43 inseminators performed alternately 87,486 first inseminations. The nonreturn rate was highly and significantly affected by month of first service, region, inseminator within region, herd with our without contract for progeny testing, parity group and the bull. When the semen was thawed for 25 s, the 75-day nonreturn rate was 0.54% and the 120-day nonreturn rate 0.45% higher than for 8 s. Though these differences were barely significant (P<.08, P<.16, resp.), they confirm nevertheless the observations of other authors. No significant interaction was found between thawing time and inseminator. According to the results of this trial, the semen temperature should be brought to the temperature of the water bath (38 +/- 2 degrees C) when thawed. A thawing time of 25 s is recommended.

Journal Article↗
PubMed1981

The primary structure of bovine satellite 1.715.

The primary structure of the 1402 bp repeat unit of bovine satellite 1.715 has been determined using a dimer inserted at the SalI site of plasmid pBR322 and cloned in E. coli. In contrast with bovine satellites 1.706, 1.720b and 1.711a, the 1.715 satellite has a complex sequence with no obvious internal short prototype repeat. The sequence consists however of repeats ranging in length from 6 to 13 nucleotides. In addition, the hexanucleotide, AGATGA, present in the prototype sequences of satellites 1.706, 1.720b and 1.711a, is found in satellite 1.715 in repeats as long as, or longer than, 8 nucleotides, establishing a homology link among those satellites on one hand and satellite 1.715 (and the related satellite 1.711b) on the other. In turn, this suggests a common evolutionary origin. A comparison of the maps for 15 restriction enzymes of cloned and uncloned satellite indicates very little sequence divergence among the repeat units of the latter, most of the differences being due to methylation.

Animals↗
PubMed1981

Helical periodicity of DNA, Poly(dA) . poly(dT) and poly(dA-dT). poly(dA-dT) in solution.

Helical periodicity of DNA, poly(dA) . poly(dT) and poly(dA-dT) . poly(dA-dT) has been measured in solution by using the band shift method fo Wang [Wang, J. (1979) Proc. Natl Acad. Sci. USA, 76, 200-203]. The method makes use of the effect, on the superhelicity of closed circular DNA molecules, of the insertion of specific nucleotide sequences of known length. The method was applied to a variety of recombinant plasmid DNAs which were constructed by inserting DNA, poly(dA) . poly(dT) or poly(dA-dT) . poly(dA-dT) into pBR322 DNA. When compared to DNA, poly(dA) . poly (dT) was found to have a smaller pitch (by about 0.5 base pair/turn), whereas poly(dA-dT) . poly(dA-dT) has a slightly larger pitch (by 0.1 base pair/turn). These features correlate well with the known ability of the alternating copolymer to reconstitute nucleosomes upon incubation with histones, in contrast to the non-alternating one which fails to do so. Finally, a detailed analysis of the principles underlying the methods developed by Wang [reference quoted above and Wang, J. (1978) Cold Spring Harb. Symp. Quant. Biol. 42, 29-33] leads to an increase in the estimate of the helical periodicity of DNA of 0.15 base pair/turn, over the reported value of 10.4 base pairs/turn (references quoted above). This essentially accounts for the discrepancy observed with the value of 10.6 base pairs/turn obtained by nuclease digestion of DNA immobilized on a surface [Rhodes, D & Klug, A. (1980) Nature (Lond.) 286, 573-578].

Base Sequence↗
PubMed1980

Excision sequences in the mitochondrial genome of yeast.

It is well established that spontaneous cytoplasmic 'petite' mutants of Saccharomyces cerevisiae have mitochondrial genome units in which an excised segment of the parental wild-type genome has been tandemly amplified (Fig. 1), so that the excised segment becomes the repeat unit of the petite genome; the latter may in turn undergo further deletions leading to secondary petite genomes having shorter repeat units (see ref. 1 for a brief review). Recent investigations on the mitochondrial genomes of several spontaneous petite mutants have shown that frequently the ends of the excised segment correspond to short sequences of the wild-type genome which are extremely rich in GC, the GC clusters; alternatively, they seem to be located in the long AT-rich stretches, the AT spacers, which form at least half of the genome. As sequence repetitions have been demonstrated in both GC clusters and AT spacers, it is very likely that excision takes place by a mechanism involving illegitimate site-specific recombination events between homologous sequences, as previously postulated. We show here that the sequences involved in the excision of a particular spontaneous petite genome are direct nucleotide repeats located in the AT spacers.

Base Sequence↗
PubMed1979

Identification of nosiheptide in feeds and detection of residues in animal tissues.

Nosiheptic is determined in fermentation broths of Streptomyces actuosus either by a microbiological method using Staphylococcus aureus or, more easily, by an automated colorimetric method. The results obtained with both methods correspond well for concentrations greater than 100 microgram/mL with a standard deviation of 1-3%. For determination of nosiheptide as a feed additive, the microbiological assay is made more specific by pretreatment with petroleum ether and 1N HCl. Standard deviation is less than 4%, and the assay is sensitive to 1 ppm. Nosiheptide is identified in feed containing other frequently used antibiotics by thin layer chromatography with bioautography; sensitivity is 1 ppm. The absence of traces of nosiheptide in tissues of treated swine and broiler is confirmed by microbiological diffusion, sensitive to 0.025 ppm.

Animal Feed↗
PubMed1975

The specificity of five DNAases as studied by the analysis of 5'-terminal doublets.

The 5'-terminal dinucleotides released by five deoxyribonucleases (spleen acid DNase, snail acid DNase, pancreatic DNase, Escherichia coli endonuclease I and crab DNase) have been determined on E. coli DNA (51% dG & dC) digests having different average sizes (Pn) in the range 50 to 10. It has been shown that the composition of the 5'-terminal dinucleotide (a) is independent upon the degradation level, at least in the range explored; (b) is strongly different from the composition of E. coli DNA doublets, these differences being characteristic for each enzyme; (c) is very significantly different from the statistical composition of 5'-terminal dinucleotides, as calculated from the composition of 5'-terminal and penultimate nucleotides. A calculation of the statistical composition of the trinucleotides split by each enzyme, using the 3'-terminal nucleotide data in conjunction with the 5'-terminal dinucleotide results provided a qualitative "specificity spectrum" for each enzyme.

Animals↗