The androgen-dependent rat prostatic binding protein: comparison of the sequences in the 5' part and upstream region of the C1 and C2 genes and analysis of their transcripts.

The complete gene encoding the polypeptide C1 of the complex androgen-controlled prostatic binding protein was isolated from a rat genomic library. A new genomic fragment (C2B) containing only the 5' part of a C2-related gene was also purified. The segments containing exon 1 and a large part of the adjacent sequences were analysed and compared with the corresponding region of the C2A gene which has been completely sequenced previously. The high structural similarity extending over a large part of all three genomic fragments suggests the duplication of a common ancestral gene, followed by a more recent duplication of the C2-coding region. However, since the structural similarity upstream of position -150 between C2A and C2B abruptly disappears and no transcripts specific for the C2B region can be detected in prostate RNA, we propose that at a later stage in evolution the C2B region was disrupted and inactivated. Despite the common origin and the similar regulation of the two active genes, C1 and C2A, the only obvious conserved structural element is the homopurine stretch located at position -400, although sequence motifs resembling steroid hormone response elements are present at several locations.

Effect of moderate or severe hepatic impairment on clarithromycin pharmacokinetics.

The pharmacokinetic and safety profiles of clarithromycin (C) and its 14-hydroxy-clarithromycin (HC) metabolite were determined after a multiple-dose oral clarithromycin regimen (250 mg twice daily for five doses) in six healthy subjects and seven patients with moderate or severe hepatic impairment (Pugh grades B and C). Plasma and urine C and HC concentrations were determined using high-performance liquid chromatography. Hepatic impairment resulted in increased harmonic mean C terminal disposition half-life and mean +/- SD C renal clearance (CLR) compared with normal volunteers (5.0 vs. 3.3 hr and 170 +/- 69 vs. 111 +/- 17 mL/min, respectively). Hepatic impairment also resulted in decreased metabolite peak plasma concentration and area under the plasma concentration-versus-time curve and decreased metabolite/parent concentration ratios compared with normal volunteers. These data suggest that 14-hydroxylation of C was reduced by moderate to severe hepatic impairment. No adverse events were noted in either study group and there were no study-related clinically significant changes in laboratory parameters. The decrease in C metabolic clearance appears to be partially offset by an increase in C CLR, resulting in comparable steady-state concentrations of parent drug. In those indications in which the metabolite may be a necessary element of the antimicrobial activity of C, it would seem prudent to be cautious in using C in patients with moderate to severe hepatic impairment due to reduced production of HC. Otherwise, no dosage adjustment for C appears necessary for subjects with moderate or severe hepatic impairment provided that renal function is not impaired.

Plasma-kinetic characteristics of purified and isolated green tea catechin epigallocatechin gallate (EGCG) after 10 days repeated dosing in healthy volunteers.

This randomized, double-blind, placebo-controlled study assessed the safety, tolerability, and plasma-kinetic behavior of 94% pure crystalline epigallocatechin gallate (EGCG) after ten days' repeated dosing in 36 healthy male volunteers. Each of the three treatment groups consisted of 12 subjects; nine of them received oral EGCG in one dose of 200, 400, or 800 mg daily, and three received a placebo. Blood samples for plasma-kinetic EGCG characterization were taken on day 1 and day 10. Kinetic parameters for rate and extent, elimination half-lives, and accumulation factor (R) were determined and compared between day 1 and day 10 for each dosage group. Orally administered EGCG is rapidly absorbed from the gut. Dose linearity was applied for single-dose application (day 1). After repeated dosing (day 10) dose linearity was applied between the 200 mg and 400 mg group. Dose escalation to 800 mg was more than dose-proportional in rate and extent, and statistically different from the 200 mg and 400 mg group. An increase in elimination half-life (t1/2.z) and in the accumulation factor (R) in the 800 mg dosage group indicates dose-dependent saturation of capacity-limited excretion routes or an increase of hepato-duodenal re-circulation. Ten days' repeated administration of oral doses of EGCG of up to 800 mg per day were found to be safe and very well tolerated.

A single ascending dose study of epigallocatechin gallate in healthy volunteers.

This randomized, double-blind, placebo-controlled study assessed the safety, tolerability and plasma kinetic behaviour of single oral doses of 94% pure crystalline bulk epigallocatechin gallate (EGCG) under fasting conditions in 60 healthy male volunteers. In each group of 10 subjects, eight received oral EGCG in single doses of 50 mg, 100 mg, 200 mg, 400 mg, 800 mg or 1600 mg, and two received placebo. Blood samples were taken at intervals until 26 h later. The area under the concentration-time curve from 0 h to infinity (AUC(0-infinity)), the maximum plasma concentration (Cmax) of EGCG, the time taken to reach the maximum concentration (Tmax), and the terminal elimination half-life (t1/2z) of EGCG were determined. Safety and tolerability were assessed. In each dosage group, the kinetic profile revealed rapid absorption with a one-peak plasma concentration versus time course, followed by a multiphasic decrease consisting of a distribution phase and an elimination phase. The mean AUC(0-infinity) of total EGCG varied between 442 and 10,368 ng.h/ml. The according mean Cmax values ranged from 130 to 3392 ng/ml and were observed after 1.3-2.2 h. The mean t1/2z values were seen between 1.9 and 4.6 h. Single oral doses of EGCG up to 1600 mg were safe and very well tolerated.

The kinetic profiles of amlodipine and of a sustained release form of diltiazem.

This study in normotensive subjects compared plasma concentrations of amlodipine (5 mg) and of a sustained release form of diltiazem (300 mg) after single and multiple oral dosings of the two drugs. As a consequence of the galenic form of administered formulations, plasma concentration of diltiazem versus time curves exhibited two peaks corresponding to fast and slow releases of diltiazem. Conversely, the curves of amlodipine plasma concentration depicted only one peak. There was less variability in plasma concentrations and in pharmacokinetics with amlodipine than with diltiazem after both single and multiple oral dosings of the two drugs. These results suggested that amlodipine displayed less variability in blood pressure response at steady-state. The rate of decrease in plasma levels of diltiazem between 24 and 48 hours post-dose was higher than that of amlodipine. So, even after a missed dose, there is only a small decline in plasma concentrations of amlodipine and therefore it suggests a small repercussion on the blood pressure attenuation.

[Pharmacokinetic properties of Bilobalide and Ginkgolides A and B in healthy subjects after intravenous and oral administration of Ginkgo biloba extract (EGb 761)]. / Propriétés pharmacocinétiques du Bilobalide et des Ginkgolides A et B chez le sujet sain après administrations intraveineuses et orales d'extrait de Ginkgo biloba (EGb 761).

The pharmacokinetics of Ginkgolide A, Ginkgolide B and Bilobalide, which are compounds extracted from the dried leaves of the Ginkgo biloba tree, were investigated in 12 young healthy volunteers (six men and six women; mean +/- SD age = 25 +/- 5 years) after single-dose administration of Ginkgo biloba extract. Subjects were given, on three occasions, Ginkgo biloba extract as a solution either orally (in fasting conditions and after a standard meal) or intravenously; corresponding to single doses of Ginkgolide A, Ginkgolide B and Bilobalide ranging from 0.90 mg to 3.36 mg. After each dosing, blood and urine samples were collected for up to 36 h and 48 h, for measurements of Ginkgolide A, Ginkgolide B and Bilobalide. Plasma and urine concentrations of these compounds were quantitatively measured by gas chromatography/mass spectrometry using negative chemical ionization, by applying a very sensitive method which allowed plasma concentrations as low as 0.2 ng/ml of each compound to be measured. When given orally, while fasting, the extents of bioavailability are high, as shown by bioavailability coefficients (FAUC) mean (+/- SD) values equal to 0.80 (+/- 0.09), 0.88 (+/- 0.21) and 0.79 (+/- 0.30) for Ginkgolide A, Ginkgolide B and Bilobalide respectively. Food intake does not change AUC quantitatively but increases Tmax. For the three compounds of interest, after oral dosing while fasting, differences can be noted for the elimination half-lives (T1/2Z), which exhibit mean values equal to 4.50, 10.57 and 3.21 h, as well as mean residence times (MRT), equal to 5.86, 11.25 and 4.89 h, for Ginkgolide A, Ginkgolide B and Bilobalide respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Human T cell clone identifies a potentially protective 54-kDa protein antigen of Toxoplasma gondii cloned and expressed in Escherichia coli.

Protective immunity against Toxoplasma gondii is recognized to be cell mediated and IFN-gamma is considered to be the major mediator of resistance. Thus, protective Ag of the parasite must induce IFN-gamma-producing T cells. In order to identify such Ag, we have constructed a T. gondii cDNA library in the cloning/expression vector lambda gt11, screened this library with a pool of sera of immune donors, and further screened the set of selected recombinant Ag using, as probe, a T. gondii-reactive T-cell clone (TCC) derived from an infected/immune individual and producing a high level of IFN-gamma. One recombinant Ag was shown to induce TCC proliferation and was characterized. The corresponding mature T. gondii Ag has an apparent molecular mass of 54 kDa and the sequence of the cDNA clone suggests that it is membrane associated. The epitope defined by the TCC on this Ag was found to be present in three Toxoplasma strains independently of their phenotype (virulent or cyst forming). Recognition of this Ag by the TCC was shown to be restricted by HLA-DPw4, the most frequent allele in the Caucasian population (approximately 40%). The use of this Ag as a vaccine component is proposed.

Rat prostatic binding protein: the complete sequence of the C2 gene and its flanking regions.

The complete sequence (2879 bp) of the androgen-controlled rat prostatic binding protein C2 gene and 1023 bp of the 5'- and 2127 bp of the 3'-flanking regions have been determined. The gene contains three exons (93, 203 and 147 bp) and two introns (1630 and 806 bp). It is flanked by two homopurine-homopyrimidine stretches of 55 and 131 nucleotides respectively, located at positions -405 and 4151. These sequences are remarkably sensitive towards S1-nuclease, indicating an altered DNA conformation under superhelical stress. Several palindromes and dyad structures are observed in the 5'-upstream region of the gene and at position -457, and 80% homology to the consensus sequence of a glucocorticoid receptor binding site is found.

The development of specific rRNA-derived oligonucleotide probes for Haemophilus ducreyi, the causative agent of chancroid.

Part of a ribosomal ribonucleic acid (rRNA) cistron of Haemophilus ducreyi was enzymically amplified using conserved primers within the rRNA molecules, cloned in a plasmid vector, and sequenced. From the nucleotide sequence, eight oligonucleotides complementary to different regions in the 16S and 23S rRNA molecules were selected, chemically synthesized, and used as hybridization probes. Hybridization experiments with at least 41 H. ducreyi strains and 13 or 14 non-H. ducreyi strains revealed that all eight oligonucleotide probes were highly reliable and completely specific for H. ducreyi strains. Comparisons of 16S rRNA sequences confirm that H. ducreyi is a member of the Pasteurellaceae though not closely related to other species in this family.