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Biomedical subjects

C Gaillard

Publications and source records attributed to C Gaillard.

At least 109 records · Page 6Linked to original sources
PubMed1992

The sucrose carrier of the plant plasmalemma. III. Partial purification and reconstitution of active sucrose transport in liposomes.

The proteins from plasma membranes from sugar beet leaves were solubilized by 1% CHAPS and separated by size exclusion chromatography and by ion-exchange chromatography. The fractions enriched in sucrose transporter were monitored in three ways: differential labeling, ELISA, and reconstitution in proteoliposomes. When the plasma membranes were differentially labeled by N-ethylamaleimide in the presence of sucrose, a major peak of differential labeling was found at 120 kDa upon gel filtration. When this peak was recovered, denaturated by sodium dodecyl sulfate and reinjected on the gel filtration column, it yielded a peak of differential labeling at 42 kDa. When unlabeled membranes were used, the fractions eluted from the column were monitored by ELISA for their ability to recognize a serum directed against a 42 kDa previously identified as a putative sucrose carrier. The results paralleled those obtained by differential labeling, i.e. a major ELISA-reactive peak was found at 120 kDa upon gel filtration, and this peak yielded a peak most reactive at 40 kDa after denaturation. The 120 kDa peak prepared from unlabeled membranes was further separated on a Mono-Q column. The fractions were monitored by ELISA as described above, and reconstituted into proteoliposomes using asolectin. Active transport of sucrose, but not of valine could be observed with the reconstituted 120 kDa fraction. When the eluates from the Mono-Q column were reconstituted, the fractions exhibiting highest transport activity were enriched with a 42 kDa band. The data provide the first report concerning reconstitution of sucrose transport activity and confirm the involvement of a 42 kDa polypeptide in sucrose transport.

Biological Transport, Active↗
PubMed1992

Plasma membrane vesicles from source and sink leaves : changes in solute transport and polypeptide composition.

Plasma membrane vesicles (PMVs) were prepared by phase partitioning from microsomal fractions of either sink or source leaves of sugar beet (Beta vulgaris L.). The purity, the internal volume, the sidedness, and the sealingness of PMVs prepared from sink leaves did not differ from those measured with PMVs from source leaves. Yet, in response to an imposed proton motive force, PMVs from source leaves accumulated about 4-fold more sucrose than PMVs from sink leaves. The developmental stage did not affect the uptake of glucose and valine in PMVs prepared from leaf tissues. It was concluded that the sink/source transition is accompanied either by the incorporation into the plasma membrane of leaf cells of proteins mediating proton-sucrose cotransport, or by their activation. N-ethylmaleimide and a polyclonal ascitic fluid directed against the 42-kD region of the plasma membrane containing a putative sucrose carrier inhibited the uptake of sucrose in PMVs from source leaves, but not in PMVs from sink leaves. Sodium dodecyl sulfate gel electrophoresis and western blot suggested that the 42 polypeptide was more abundant in the PMVs from source leaves than in the PMVs from sink leaves.

Journal Article↗
PubMed1992

Selective Inhibition of Active Uptake of Sucrose into Plasma Membrane Vesicles by Polyclonal Sera Directed against a 42 Kilodalton Plasma Membrane Polypeptide.

Several polyclonal sera were raised in rabbits and in mice against putative sucrose carrier proteins, i.e. a 42 kilodalton (O Gallet, R Lemoine, C Larsson, S Delrot [1989] Biochim Biophys Acta 978: 56-64) and a 62 kD (KG Ripp, PV Viitanen, WD Hitz, VR Fransceschi [1988] Plant Physiol 88: 1435-1445) polypeptide of the plasma membrane. The effects of these sera on the active uptake of sucrose and of valine into purified plasma membrane vesicles from sugar beet (Beta vulgaris L.) leaves and roots were studied. At a dilution of 1/50, the anti-42 kilodalton sera consistently inhibited sucrose uptake in plasma membranes from leaves or from roots. They had no effect on valine uptake. Under the same experimental conditions, the anti-62 kilodalton sera had no effect on active uptake of sucrose. The data further support the view that a 42 kilodalton polypeptide is a component of the transport system mediating sucrose uptake across the plasma membrane of plant cells.

Journal Article↗
PubMed1992

DNA fingerprinting in cattle using the probe pV47.

The multilocus probe pV47 detected an average of nine bands in cattle between 23 kb and 4 kb. Band sharing was estimated for three groups of unrelated animals. The first group comprised 20 individuals of 12 different breeds, the second group 10 individuals of the Swiss Simmental population and the third group 11 individuals of the Swiss Brown Swiss population. The band sharing probabilities were 33%, 42% and 58% respectively. The DNA fingerprints of 38 offspring with a total of 277 bands revealed no bands that could not be traced to the parents.

Animals↗
PubMed1991

Reconstitution of active sucrose transport in plant proteoliposomes.

The proteins of purified plasma membranes from sugar beet (Beta vulgaris L.) leaf were solubilized and separated on a size exclusion column. The fractions eluted from the column were monitored by ELISA with antibodies directed to a putative sucrose carrier protein. The peak most reactive in ELISA was approximately 120 kDa, and yielded a 40 kDa peak after denaturation by SDS. The 120-kDa peak was recovered and used for reconstitution experiments with asolectin. Upon imposition of an artificial pH gradient and electrical gradient, the obtained proteoliposomes exhibited active transport of sucrose, but not of valine. The active transport of sucrose was inhibited by N-ethylmaleimide and HgCl2.

Antibody Specificity↗
PubMed1990

Sequence-specific single-strand-binding protein for the simian virus 40 early promoter stimulates transcription in vitro.

We have detected, in nuclear extracts of non-infected cultured monkey cells, a protein (protein H16) that binds a specific single-stranded DNA sequence in the early promoter of simian virus 40 (SV40). This protein does not bind double-stranded DNA, nor RNA. In the present paper, the DNA-binding properties of protein H16 and its effects on transcription by RNA polymerase II in vitro have been investigated. The protein binds only to the late strand of the early promoter, within the region of the 21 base-pair repeats, and shows no affinity for any other SV40 sequence. The high percentage of cytosine residues in the late strand in this region appears to be important for recognition by the protein. Protein H16 does not bind the control region of SV40 in negatively supercoiled DNA circles. When bound to the late strand, the protein is displaced from its binding site by reassociation of the early strand with the late strand. Its binding to DNA is not sensitive to methylation of the dinucleotide CG in its binding site. The protein has been purified to near homogeneity by preparative gel retardation, and has an apparent molecular weight of 70,000. Purified protein H16 stimulates transcription by purified RNA polymerase II in vitro. The possible role of sequence-specific single-strand-binding proteins in transcription is discussed.

Base Sequence↗
PubMed1990

Influence of major histocompatibility complex on reproduction and production traits in swine.

The effects of the swine lymphocyte antigen (SLA) system on different performance traits were investigated in Swiss pig breeds. Litter size and piglet weight at birth and at weaning were considered and in gilts the average daily weight gain, backfat and muscle thickness as well as percentage valuable cuts were measured. These data were analysed with least squares procedures. Although the effect of SLA on these traits was very small, a few haplotypes seemed to have some influence. Sows of the Large White breed carrying H12 had a significant smaller and those with H24 had a bigger litter size at weaning. Some mating studies were performed to investigate the effects of SLA homozygosity. The obtained results suggest that this has a negative effect on the litter size, especially when H19 in the Large White breed and H7 in Landrace are involved.

Analysis of Variance↗
PubMed1990

[Diseases and culling of Swiss dairy cows. 2. Culling and relation between diseases and milk production parameters].

During three years (1982 to 1984) data were collected concerning diseases and reasons for culling in 612 dairy farms with Brown Swiss, Simmental and Black and White cattle. The frequency of culling increases in all three breeds with increasing age, from 20% at the first lactation up to 33% from the 4th lactation on. The main reasons for disposal are insufficient production, reproductive problems or udder diseases. After treatment for reproductive problems, mastitis or acetonemia, the risk for culling within the same lactation period is increased. Reproductive problems (no heat symptoms, repeat breeder, ovarian cysts) and acetonemia increase with increasing milk production in all three breeds. In cows with high 100-day-performance they are also more frequent. The occurrence of acute mastitis shows no general trend with increasing milk production or with high 100-day-performance. No systematic relationship is found between reproductive disorders or acute mastitis and persistency of milk production. On the other hand, acetonemia is somewhat more frequent in cows showing higher persistency.

Age Factors↗
PubMed1989

Pharmacokinetics of nicorandil.

This report presents the findings of some studies on single intravenous and oral dosing performed in healthy volunteers to determine the pharmacokinetics and preliminary metabolism of nicorandil, a new vasodilator acting via increase of both membrane potassium conductance and intracellular cyclic guanosine monophosphate in vascular smooth muscle. Nicorandil (5 to 40 mg) is rapidly and completely absorbed after oral administration. Absolute bioavailability is 75 +/- 23% (mean +/- standard deviation) indicating that no significant hepatic first-pass effect exists; peak plasma levels occur within 0.30 to 1.0 hours after dosing. Maximal concentration and area under the plasma concentration time curve of the parent drug are linearly related to a dose range of 5 to 40 mg, which covers the therapeutic regimen proposed for the treatment of patients with angina pectoris. The apparent distribution volume is about 1.4 liters/kg and the plasma concentrations decline according to 2 different processes: (1) a rapid elimination phase (apparent t1/2 beta congruent to 1 hour) that involves about 96% of the dose found in plasma, and a slower phase between the eighth and twenty-fourth hour that could be the consequence of the vascular affinity of the compound. Nicorandil is weakly bound to human plasma proteins (free fraction greater than 75%) and its mean residence time is close to 1.25 hour. Both in animals and in humans, preliminary metabolic studies show that the main biotransformation pathways are denitration and then introduction into the nicotinamide metabolism. However, unchanged nicorandil and denitrated metabolite excreted into the urine represent only about 1 and 4% of the dose, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1988

A sequence-specific single-strand-binding protein for the late-coding strand of the simian virus 40 control region.

We have purified a protein from uninfected monkey CV1 cells that binds specifically in vitro to the late-coding simian virus 40 DNA strand in the region of transcription control without any detectable binding to the complementary single strand. Nuclease protection experiments detected two binding sites in the 21-base-pair repeat region. The protein did not bind to this region in the double-stranded form, nor did it bind to RNA synthesized in vitro by using either DNA strand as a template. This protein, and perhaps other DNA single-strand-sequence-specific proteins, may play a role in the control of gene expression in higher organisms.

Base Sequence↗
PubMed1985

Carpipramine metabolism in the rat, rabbit and dog and in man after oral administration.

Carpipramine administered orally is excreted via the urine and faeces in rat, rabbit, dog and man. Many metabolites are formed, including several conjugates in the urine. A total of 20-25 metabolites was detected by t.l.c. and h.p.l.c., 16 of which were isolated and identified. Three metabolic pathways were observed: hydroxylation of the iminodibenzyl ring to a phenol or alcohol without modification of the side-chain, hydroxylation of the terminal piperidine of the 2-piperidinol side-chain, and cyclization and dehydrogenation of the same 2-piperidinol group.

Animals↗
PubMed1984

[Peptic lesions of the upper digestive tract and drugs. Prospective study].

The association between drugs and diseases of the gastrointestinal tract is well known but has always been evaluated qualitatively and not quantitatively. To study the importance of this association, a prospective study was undertaken at the University of Geneva Hospital in 456 subjects. A statistically significant (p less than 0.05) correlation was found in the following associations: aspirin and multiple gastric ulcers, aspirin and severe erosive gastritis; non-steroidal antiinflammatory drugs and multiple duodenal ulcers, non-steroidal antiinflammatory drugs and mild erosive gastritis. On the other hand, no correlation was found between any of the observed gastrointestinal diseases and prednisone, alcohol or tobacco.

Adult↗
PubMed1983

[Quantitative approach to drug compliance of diabetics].

Many patients do not take their medication according to the instructions of their physician. Patient compliance is particularly poor in the long-term treatment of diseases, which produce only minor symptoms in the patient. The aim of the present study was to quantitate patient compliance in diabetics treated with tolbutamide. The amount of tolbutamide taken by the patient was estimated on the basis of its 24 hours urinary excretion. The collection of the 24 hours urine is a standard procedure in our outpatient clinic for the measurement of glycosuria. The study involved 33 diabetics followed over several months. In those reliable patients, who conscientiously took their medication, we found a good correlation between the prescribed dose and the 24 hours urinary excretion. In contrast, when the data from the entire group of 33 out-patients was evaluated, the correlation between these two parameters of prescribed dose and urinary excretion was poor. The correlation between urinary excretion and the dose admitted by the patient was just as poor. According to our results, only one out of two diabetics took the prescribed dose. After our initial observations, we informed the outpatients about their inclusion in this study. In spite of the fact that the patients knew that they were under observation for compliance, we found large interindividual differences in the urinary excretion of tolbutamide over several months. In contrast, the intraindividual variability was low. We found that interviews with patients are a poor means to detect non-compliance, whereas urinary excretion measurements appear to be more reliable.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus↗