L Balant

University of Geneva, Genève, Geneva, Switzerland

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Publications (105)244.88 Total impact

  • Journal of Clinical Pharmacy and Therapeutics 06/2008; 4(2):87 - 93. · 2.10 Impact Factor
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    ABSTRACT: Digoxin serum levels are measured after intravenous infusion of a 2 mg dose. The pharmacokinetic parameters for a two and three-compartment open-body model are calculated by compartmental analysis using a digital computer; the three-compartment open-body model gives the superior fit.The behaviour of digoxin during multiple administration is predicted and compared to the experimental results obtained after eleven intravenous injections of 0·5 mg digoxin.For pharmacokinetic and pharmacodynamic purposes the behaviour of digoxin in man is best described by a three-compartment open body model. For clinical purposes, such as determining the optimum dosage regimen for individual patients, a simpler moder might be adequate and easier to use.
    Journal of Clinical Pharmacy and Therapeutics 06/2008; 5(1):35 - 42. · 2.10 Impact Factor
  • L. Balant, C. A. Hunt
    Journal of Clinical Pharmacy and Therapeutics 06/2008; 5(1):31 - 34. · 2.10 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the possible advantages of floating and high-density dosage forms and their influence on pharmacokinetic parameters. Atenolol was chosen as a model drug because of its poor absorption in the lower gastrointestinal tract. Three formulations containing 25 mg atenolol, a floating multiple-unit capsule, a high-density multiple-unit capsule, and an immediate-release tablet were compared with respect to estimated pharmacokinetic parameters. The two multiple-unit dosage forms were composed of compressed minitablets and had sustained release properties. The bioavailability of the two gastroretentive preparations with sustained release characteristics was significantly decreased when compared to the immediate-release tablet. The floating minitablets seemed to be retained longer in the stomach than the high-density dosage form. The first atenolol concentration detectable in the plasma and the time to peak Tmax were delayed for the floating dosage form. For the parameters Cmax and AUC 0-infinity, the lower limit of the 90% confidence interval was outside the bioequivalence range (0.80-1.25). This study showed that it was not possible to increase the bioavailability of a poorly absorbed drug such as atenolol using gastroretentive formulations. Atenolol absorption was delayed and the maximum plasma concentration was diminished.
    Pharmaceutica Acta Helvetiae 08/1998; 73(2):81-7.
  • Process Biochemistry 01/1998; 33(1). · 2.52 Impact Factor
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    ABSTRACT: The aim of this study was to quantitate the density of guanine nucleotide-binding (G) protein subunits (inhibitory G alpha i, stimulatory G alpha s, G alpha q/11, and G beta) in platelets of unipolar depressed patients to assess the status of these signal transduction proteins in depression and the effects of antidepressant drug treatment. Blood platelets were collected from 22 drug-free depressed patients and 22 age- and sex-matched healthy controls. The levels of the various G protein subunits were assessed by immunoblotting techniques. The immunoreactivity of G alpha 12 was increased (41%) and that of G alpha i3 decreased (25%) in platelets of depressed patients. The levels of other G protein subunits (G alpha s, G alpha q/11, G beta) did not change significantly with respect to those of control subjects. Chronic administration of cyclic antidepressant drugs (citalopram, clomipramine, imipramine) decreased the immunoreactivity of the up-regulated G alpha i2 protein (31%). Since platelet G alpha i2 is in line with the existence of supersensitivity of these receptors in major depression.
    Biological Psychiatry 11/1997; 42(8):704-12. · 9.47 Impact Factor
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    ABSTRACT: The objective of the present study was to determine the basis for dosing time-dependent changes in the ocular and systemic absorption of topically applied timolol in pigmented rabbits. The gamma scintigraphic technique was used to monitor the changes in precorneal solution retention following instillation. Changes in timolol concentration in the plasma over 120 min and in various anterior segment eye tissues at 30 min following the topical instillation of 25 microliters of 0.65% timolol maleate solutions at various dosing times were monitored using reversed phase HPLC. Corneal and conjunctival permeability at various dosing times was evaluated in the modified Ussing chamber. The results indicated that precorneal solution drainage was slowest at noon. Suppressing tear production by anesthesia led to an increase in ocular timolol absorption at 6 a.m. but not at other dosing times, in spite of the lowest corneal permeability then. There was no statistically significant dosing time influence on systemic timolol absorption following nasal or conjunctival dosing. In conclusion, possible diurnal changes in precorneal solution clearance may be the main factor underlying the diurnal changes in ocular as well as systemic timolol absorption in rabbits. In addition, diurnal changes in corneal permeability may also contribute to diurnal changes in ocular timolol absorption.
    Journal of Ocular Pharmacology and Therapeutics 02/1996; 12(2):103-13. · 1.42 Impact Factor
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    ABSTRACT: Glycoprotein modifications in the glycan moiety can occur in diseases such as cancers, inflammatory processes and alcoholism. We combined high-resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) with lectin affinoblotting in order to establish the normal human plasma glycoprotein map. Human plasma proteins were separated by mini 2-D PAGE (7 x 9 cm), transferred onto polyvinylidene difluoride membranes and incubated with biotinylated lectins. We focused our study on lectins binding sialic acid and galactose residues. Known plasma glycoproteins such as alpha 1-antitrypsin, alpha 1-antichymotrypsin, alpha 2-HS glycoprotein, alpha 1-acid glycoprotein, haptoglobin beta-chain and transferrin were easily detected in ng amounts. This protocol was adequate to establish a normal plasma glycoprotein map and will allow the study of glycoproteins in diseases.
    Electrophoresis 08/1995; 16(7):1187-9. · 3.16 Impact Factor
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    ABSTRACT: Self reports of flushing reaction after drinking, cutaneous sensitivity to alcohol (patch test), and genotypic determination of ADH2, ADH3, and ALDH2 were studied in 53 Brazilian volunteers of different ethnic groups. Genotypes were determined using single-strand conformation polymorphism in discontinuous buffer electrophoresis. Analysis of the results indicated several cases of a reported flushing reaction among ALDH2 1/1 individuals, while all but 2 cases of ALDH2 heterozygotes reported a flushing reaction. The latter subjects also had a negative result in the patch test. These preliminary results indicate that variability in the facial flushing reaction to alcohol seems to be a phenomenon resulting not only from the presence of a deficient ALDH2*2 allele, but also from other polymorphisms of alcohol-metabolizing enzymes.
    Brazilian Journal of Medical and Biological Research 06/1995; 28(5):513-8. · 1.03 Impact Factor
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    ABSTRACT: The influence of genetic variation in alcohol dehydrogenase (ADH; EC 1.1.1.1) and aldehyde dehydrogenase (ALDH; EC 1.2.1.3) on the metabolic pattern of serotonin (5-hydroxytryptamine, 5-HT) in humans was examined from the relative urinary concentrations of the end products 5-hydroxyindole-3-acetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTOL). Healthy Caucasian (Swedish) and Oriental (Chinese) subjects were genotyped for ADH2, ADH3 and ALDH2 by a PCR/SSCP technique. The 5-HTOL/5-HIAA ratios ranged between 0.9-9.4 pmol/nmol (4.4 +/- 1.8, mean +/- SD, n = 143). No significant difference in the 5-HT metabolic pattern was observed between Caucasians and Orientals (4.3 +/- 1.8 and 4.4 +/- 1.8 pmol/nmol, respectively), nor between any of the ADH2, ADH3 and ALDH2 genotypes. Despite the modulatory effects of genetic variation of these enzymes on ethanol metabolism, the present results indicate that the individual isozyme composition of ADH2, ADH3 and ALDH2 is not important for the metabolic pattern of 5-HT.
    Life Sciences 02/1994; 55(5):359-66. · 2.30 Impact Factor
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    ABSTRACT: Under appropriate conditions single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) products allows the detection of single base mutations in a given DNA fragment. We adapted this method for the routine determination of allele variants of human alcohol and acetaldehyde dehydrogenase without radioisotopic labeling. After PCR amplification of the selected exon, the DNA fragments were heat-denatured and loaded on a polyacrylamide gel containing glycerol. For electrophoresis a discontinuous buffer system was used with sulfate as leading ion and borate as trailing ion. The DNA bands were revealed by silver staining. Acrylamide concentrations, ionic strength and electrophoresis temperature were systematically investigated for each DNA fragment. The polymorphisms detected by SSCP were identical to those found by hybridization with 32P-labeled allele-specific oligonucleotides. This method avoids the use of radioactivity, is less expensive and simpler than the allele-specific oligonucleotide (ASO) methodology and thus particularly suited for routine analysis.
    Electrophoresis 08/1993; 14(7):566-9. · 3.16 Impact Factor
  • J Fabre, J P Assal, L Balant, P Dayer
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    ABSTRACT: Approximately one half of the patients takes prescribed medications irregularly or omits these altogether. On the basis of our own observations and published reports we analyze the factors influencing compliance. The motivation of the patients plays a decisive role, it is rooted in the meaning the patient gives to his existence, to where the strength of his family bonds and the confidence in the care-taking persons lays as well as the possibility to express himself which is most important. The better guidance and training of the doctors in the difficult task of strengthening such motivation may contribute to substantially improve this situation.
    Schweizerische Rundschau fur Medizin Praxis = Revue suisse de medecine Praxis 03/1992; 81(6):129-32.
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    ABSTRACT: The aim of this study was (a) to establish a red blood cell (RBC) protein map with immobilized pH gradient for the first dimension (b) to compare the pattern with previously published RBC protein map obtained with carrier-ampholyte pH gradients and (c) to localize four new enzymes on the map (i.e. 6-phosphogluconic dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutathione peroxidase and superoxide dismutase). This publication provides the most updated RBC polypeptide pattern with twelve proteins or enzymes localized on the map.
    Applied and theoretical electrophoresis: the official journal of the International Electrophoresis Society 02/1992; 3(2):77-82.
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    ABSTRACT: Examined the feasibility and accuracy of the Brief Psychiatric Rating Scale (BPRS) as an evaluative tool. 80 psychiatric inpatients (aged 17–63 yrs) were evaluated with the BPRS on the day of admission and every subsequent 10th day. Results indicate that the BPRS shows a factor structure that is consistent with previous studies (e.g., J. E. Overall; 1974). The BPRS represents a level of abstraction that is compatible with the way clinicians think and communicate about manifest psychopathology. Finally, the BPRS is sensitive to changes in the patient's condition during pharmacological treatment. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
    European Psychiatry 01/1991; · 3.21 Impact Factor
  • Revue medicale de la Suisse romande 01/1988; 107(12):1007-12.
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    ABSTRACT: The aim of this study was to investigate the effect of chronic renal insufficiency on absorption, distribution and elimination of D-xylose which was chosen as a "test substance". Pharmacokinetic analysis was based on eighteen D-xylose tests carried out either by the enteral or parenteral route in a randomized fashion on nine patients suffering from chronic renal insufficiency. These results were compared with those obtained in healthy volunteers. The renal clearance was simultaneously measured with the 51Cr-EDTA test. In the experimental conditions the intestinal absorption of D-xylose was not modified qualitatively (absorption rate) nor quantitatively (systemic availability). Inspite of this, the maximal concentration of the D-xylose was higher in these patients and was reached later than in healthy volunteers. This fact should be taken into consideration when interpreting the results of a D-xylose test in patients suffering from chronic renal insufficiency.
    Gastroentérologie Clinique et Biologique 01/1988; 12(6-7):542-7. · 1.14 Impact Factor
  • A E Balant-Gorgia, L Balant
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    ABSTRACT: Antipsychotic drugs (neuroleptics) are candidates for plasma concentration monitoring, but not all agents have the same potential in this respect. The present review analyses the available data on the kinetics and metabolism of fluphenazine, perphenazine, thiothixene, flupenthixol, clopenthixol, haloperidol, pimozide, penfluridol, sulpiride and clozapine. Although some of the drugs described in this review have been in use for many years, knowledge of their pharmacokinetics is still only approximate. This is primarily because determination in biological fluids is not always feasible. Accordingly, analytical methods useful for pharmacokinetic studies or plasma concentration monitoring of these antipsychotic drugs are discussed. With the exception of sulpiride, all the neuroleptics reviewed share some basic pharmacokinetic properties: good gastrointestinal absorption but reduced systemic availability because of hepatic first-pass metabolism, high hepatic clearance and a large apparent volume of distribution leading to an apparent elimination half-life of about 24 hours for most of these compounds. The renal elimination is negligible and it seems that these drugs do not possess active metabolites. The pharmacokinetic properties of antipsychotic drugs are important for the inclusion of a set of drugs in a psychiatric institution where there is a possibility of drug concentration monitoring. In addition, the availability of a depot preparation is of importance. These factors are discussed in view of the experience made during the last years in the University Psychiatric Institutions of Geneva.
    Clinical Pharmacokinetics 09/1987; 13(2):65-90. · 5.49 Impact Factor
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    ABSTRACT: A patient showed excessive concentrations of desmethylclomipramine after receiving normal daily doses of clomipramine (Anafranil) and the elimination kinetics of the desmethylated metabolite was zero-order/saturable. Investigation showed that she was a poor metabolizer of debrisoquine and that, in addition, she had been treated with allopurinol, an inhibitor of hepatic drug metabolism.
    European Journal of Clinical Pharmacology 02/1987; 32(1):101-2. · 2.70 Impact Factor
  • Revue medicale de la Suisse romande 01/1987; 106(12):1073-87.
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    ABSTRACT: In man, unabsorbed disaccharide lactitol is fermented by colonic flora with an H2 breath production proportional to the absorbed quantity. The osmolality of the ingested solution is without effect either on the oro-cecal transit time and the time of H2 peak, or on the output and peak value of H2 expired. The intestinal symptoms seemed less prominent with slighter osmolality. The beginning of H2 production and the amount of H2 recorded varied widely between different subjects and in the same subject. It is thus important to consider this variability when measuring transit time and evaluating the amount of unabsorbed sugar. The comparison between two analogous doses of lactitol and lactulose (Duphalac) shows lower H2 production with lactulose, but clinical symptoms are slightly more pronounced. The glycemic peak was significantly higher for lactulose than for lactitol.
    Schweizerische medizinische Wochenschrift 05/1986; 116(15):469-72. · 1.68 Impact Factor

Publication Stats

859 Citations
244.88 Total Impact Points

Institutions

  • 1970–2008
    • University of Geneva
      • • Department of Psychiatry
      • • Department of Rehabilitation and Geriatrics
      • • Department of Biochemistry
      Genève, Geneva, Switzerland
  • 1994
    • Karolinska Institutet
      • Institutionen för klinisk neurovetenskap
      Solna, Stockholm, Sweden
  • 1980–1981
    • Policlinique Médicale Universitaire Lausanne
      Lausanne, Vaud, Switzerland