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N De Clercq

Publications and source records attributed to N De Clercq.

15 recordsLinked to original sources
PubMed2001

A prospective, randomized, comparative US trial of a combination hepatitis A and B vaccine (Twinrix) with corresponding monovalent vaccines (Havrix and Engerix-B) in adults.

In an open, randomized, multicenter, controlled clinical trial in the US, 773 adults were administered either a combination hepatitis vaccine (Twinrix: 720 EL.U inactivated hepatitis A antigen and 20 mcg recombinant hepatitis B surface antigen per milliliter) on a 0, 1, 6 month schedule or corresponding monovalent vaccines concurrently (Havrix, 1440 EL.U/ml of hepatitis A antigen at 0, 6 months and Engerix-B, 20 mcg of hepatitis B surface antigen at 0, 1, 6 months). Non-inferiority testing for the primary endpoint, severe soreness, and equivalence testing for the secondary endpoints, anti-HAV seroconversion and anti-HBs seroprotection, showed that safety and immunogenicity were comparable in the two groups.

Adult↗
PubMed2001

A prophylactic hepatitis B vaccine with a novel adjuvant system.

Studies with recombinant hepatitis B vaccines show seroprotection rates varying between 91 and 100%. Thus, a limited risk may remain for non-responding populations (e.g. non-responders, haemodialysis patients, elderly) who could benefit from a more immunogenic hepatitis B vaccine. One strategy to enhance the immune response is the use of novel adjuvants. SmithKline Beecham has developed a new adjuvant system containing alum and 3-deacylated monophosphoryl lipid A: SBAS4 (SmithKline Beecham Adjuvant System 4). Pilot studies showed that SBAS4 improved in vivo humoral and in vitro cellular immune responses compared to the response to classical recombinant hepatitis B vaccines and was safe and well-tolerated. Several studies assessed the profile of the HBsAg/SBAS4 vaccine in a healthy population, non-responders or elderly. In general the HBsAg/SBAS4 vaccine was well tolerated. Compared to an established recombinant hepatitis B vaccine, we observed an increased local reactogenicity but few symptoms were reported as severe. The HBsAg/SBAS4 vaccine elicits a strong immune response: subjects are protected faster and the GMTs are usually much higher. HBsAg/SBAS4 thus has the potential to protect those subjects who fail to be protected by well established hepatitis B vaccines.

Adjuvants, Immunologic↗
PubMed2000

A comparison of two commercial recombinant vaccines for hepatitis B in adolescents.

The immunogenicity and reactogenicity profiles of three doses each of Engerix-B(R) (10 microg hepatitis B surface antigen) and Recombivax(R) (5 microg hepatitis B surface antigen), given on a 0, 1, 6 month schedule to healthy adolescents were compared in a single-blind, randomized clinical trial. One month following the third dose, seroprotection rates after Engerix-B and Recombivax were similar (99 and 98%, respectively). The geometric mean titre (GMT) was statistically significantly higher following vaccination with Engerix-B (3961 vs. 1001 mIU/ml; P=0.0001, Fisher's exact test). Most of the symptoms reported were mild or moderate in intensity and transient. There were no vaccine-related serious adverse events.

Adolescent↗
PubMed2000

Reactogenicity and immunogenicity of a Lyme disease vaccine in children 2-5 years old.

Two doses of a recombinant Lyme disease vaccine (15 and 30 microg) were administered to children 2-5 years old (0-1-month schedule) and were well tolerated. Both doses were highly immunogenic with geometric mean titers 1 month after vaccination of 4366 and 9877 ELISA units (EU)/mL, respectively. Nearly all subjects had antibody levels of > or = 1400 EU/mL, suggesting protective tick titre for one tick season.

Antibodies, Bacterial↗
PubMed1999

Immunogenicity of a recombinant Borrelia burgdorferi outer surface protein A vaccine against Lyme disease in children.

BACKGROUND AND OBJECTIVE: A recombinant lipoprotein vaccine against Lyme disease, containing 30 microg of Borrelia burgdorferi outer surface protein A (OspA) with aluminum adjuvant, has been shown in a large US field trial of subjects >/=15 years of age to offer 76% efficacy against clinical Lyme disease after 3 injections given at 0, 1, and 12 months. Lyme disease is also an important problem in children; thus, OspA vaccine trials in children are needed. The purpose of this study was to investigate the safety and immunogenicity of 2 different doses of lipoprotein OspA with aluminum adjuvant vaccine in healthy children 5 to 15 years of age in a double-blind, randomized study. STUDY DESIGN: In a double-blind study, 250 children from the Czech Republic were randomly assigned to receive 15 microg or 30 microg of OspA vaccine at 0, 1, and 2 months. Serum samples, obtained before vaccination and 1 month after the second and third doses, were analyzed for antiOspA antibody. Solicited and unsolicited symptoms were collected from diary cards. RESULTS: Local pain at the injection site was reported by approximately 76% of the 250 children. Headaches (after 5% to 18% of the injections) and malaise (after 2% to 16% of the injections) were the most frequently reported general symptoms. Local and generalized symptoms were not different between the 15 microg and 30 microg groups, and all symptoms resolved within 4 days. Both doses were highly immunogenic, with the 30 microg dose eliciting higher antibody levels. Seroconversion occurred in 99% of the 250 children. CONCLUSIONS: The OspA vaccine against Lyme disease was well tolerated and highly immunogenic in children.

Adolescent↗
PubMed1996

Deterioration of sperm quality in young healthy Belgian men.

We have retrospectively analysed the sperm characteristics of 416 consecutive healthy young men who presented themselves in the past 19 years as candidate sperm donors. Ejaculate volume increased slightly (P = 0.067), and average sperm concentration decreased (P = 0.035) by 12.4 x 10(6)/ml over the observation period, so that sperm count per ejaculate remained unchanged (P = 0.91). In contrast, sperm morphology (r = - 0.23, P < 0.0001), rapid progressive motility (r = - 0.42, P < 0.0001) and total motility (r = - 0.33, P < 0.0001) presented an important and time-related decrease. When a quadratic model was used rather than a linear one to analyse the data on rapid progressive motility, there appeared to have been no further decline since 1990. The average proportion of spermatozoa with normal morphology decreased from 39.2% in the period 1977-1980 to 26.6% in 1990-1995 (P < 0.0001), and the mean percentage of spermatozoa with rapid progressive motility decreased from 52.7 to 31.7% (P < 0.0001). The percentage of candidate donors with sperm characteristics below the 5th percentile cut-off value of a normal fertile population increased from 13 to 54% during the observation period (P < 0.0001). Since the technique of semen analysis has remained essentially unchanged in-so-far as has been practically possible, as has the method of recruitment of candidate sperm donors, the observed deterioration of sperm characteristics is considered to reflect degeneration of sperm production among men aged between 20 and 40 years.

Adult↗
PubMed1995

Statement on the general reduction in sperm quality.

Over a period of 17 years, 360 young healthy men presented themselves as candidate donors for the sperm bank of the University Hospital of Ghent. Semen characteristics of these men were assessed using unaltered methods, and analysis was performed on the first sample delivered before any donor selection was performed. Sperm motility and morphology, but not the total sperm count per ejaculate, exhibited a highly significant decrease. Over 40% of candidate donors since 1990 exhibited subnormal sperm characteristics, as against only 5% of the group investigated before 1980.

Adult↗
PubMed1994

Methodological aspects of sperm morphology evaluation: comparison between strict and liberal criteria.

OBJECTIVE: To compare the methodological accuracy of different sperm morphology criteria. SETTING: A multicenter study including 10 laboratories with high expertise in semen analysis. PATIENTS: Semen preparations of subfertile men with a variable degree of teratozoospermia and of fertile semen donors. INTERVENTIONS: Detailed assessment of sperm morphology on 10 air-dried semen smears, of which 3 originated from the same ejaculate. RESULTS: The average coefficient of variation calculated on the three smears of the same ejaculate was higher when strict criteria for morphological normality were used and borderline cells were classified as abnormal than when criteria of abnormality were applied and borderline cells were considered normal. The correspondence between individual centers mutually and of each center with the average result of all centers was better when the latter approach was taken. The performance of two computer-assisted systems was intermediate between that of the two approaches, whereas one system gave unreliable results. CONCLUSIONS: Strict criteria for normality of sperm morphology, with borderline cells considered abnormal, gives results that are less reproducible and less accurate than the approach that classifies sperm as abnormal, with borderline cells considered normal.

Fertility↗
PubMed1993

Structure of rat genes encoding androgen-regulated cystatin-related proteins (CRPs): a new member of the cystatin superfamily.

Cystatin-related proteins (CRPs) are abundant androgen-regulated secretory glycoproteins that are specifically synthesized in the ventral prostate and lachrymal gland of the rat. Two complete 6-kb genes, Crp1 and Crp2, have been cloned and characterized. They are differentially expressed and encode slightly different proteins. The genes each contain four exons which are interrupted by large introns. An alignment of their sequences demonstrates an overall homology of 90%. The 3' end of a third gene, Crp3, from which only a 1.5-kb fragment was isolated, displays a sequence identity of 84%. These data indicate the existence of a Crp multigene family. The 5' flanking regions of Crp1 and Crp2 are highly homologous and contain a GATAAA sequence 29 nt upstream from the transcription start point. This TATA-box-like element is also found in the promoters of the genes encoding cystatin type-2 proteins. No other recognizable transcription control elements can be detected. Potential binding sites (ARE) for the androgen receptor are scattered throughout the entire genes. The exon/intron organization of the genes encoding CRPs, the size of the exons and their encoding amino acid sequences exhibiting a characteristic spacing of the Cys residues are structural elements displaying a remarkable similarity with the corresponding elements in the genes encoding cystatin type-2 proteins. CRPs must therefore belong to the cystatin superfamily. However, due to their additional domain encoded in an extra exon 2, CRPs must be classified as a new family, type 5.

Amino Acid Sequence↗
PubMed1992

The 4.4-kilodalton proline-rich polypeptides of the rat ventral prostate are the proteolytic products of a 637-kilodalton protein displaying highly repetitive sequences and encoded in a single exon.

We have determined the complete sequence of the 637-kilodalton precursor for the proline-rich polypeptides (PRPs). This protein is encoded in one large exon of a single copy gene. The acidic precursor of 5761 residues comprises a signal peptide and three large domains displaying a high proline content (11-15%). The sequence of domain A (928 residues) is unique and contains several small clusters of acidic amino acids. Domain B (830 residues) exhibits seven tandem repeats, four of them displaying a strongly diverged sequence. In domain C (3914 residues) 39 units, of which only 8 are degenerate, occur in a tandem repeat. Their sequence of 100 amino acids shows a high structural similarity (76-92%) and contains all the PRP variants which are produced by specific proteolytic processing. The COOH-terminal part (35 residues) is basic. Two variant PRP-precursor alleles occur which slightly differ in the number of repeats in domain C. The high degree of sequence conservation within the repeat regions suggests that the gene presumably evolved by multiple amplification and dispersion of two internal segments. In the 5097-base pair genomic region 5' upstream from the translation start, several control elements for transcription are recognized. A potential binding site for the Sp1 factor (GGGCGG) separated by 47 nucleotides from an initiator motif, most probably elements of the promoter, is detected in the vicinity of the ATG codon. Several putative androgen response elements (TGTYCT) are found in the 5' adjacent region and far upstream two Alu type III repeats and two (CA)n repeats are located. These results provide the basis for a detailed study of the androgen-regulated and tissue-specific expression of the PRP-precursor gene.

Amino Acid Sequence↗
PubMed1990

Tissue-specific expression and androgen regulation of different genes encoding rat prostatic 22-kilodalton glycoproteins homologous to human and rat cystatin.

22-Kilodalton (kDa) protein cDNA clones were isolated from a rat prostatic library. Nucleotide sequence analysis revealed three different cDNA sequences encoding two somewhat different open reading frames of 176 amino acids. The N-terminal 24 amino acids of these sequences show the typical characteristics of signal peptides of secretory proteins. The C-terminal end of the derived protein sequences displays sequence similarity to a number of cysteine proteinase inhibitors, called cystatins, suggesting a common physiological function. Upon Northern blotting with a labeled cDNA fragment, three different 22-kDa protein mRNAs, i.e. 950 nucleotides (nt), 920 nt and 860 nt, could be detected in the rat ventral prostate and the lacrymal gland. In both tissues these messengers were regulated by androgens showing the most rapid androgen response for the 950 nt mRNA form. Administration of cycloheximide nearly completely abolished the observed androgen effect suggesting that a short-living protein is required for the full induction of the 22-kDa protein genes. Hybridization experiments with specific oligonucleotides which distinguish between the mRNAs encoding both 22-kDa protein variants indicate that one protein form is less androgen dependent in the ventral prostate and not expressed in the lacrymal gland.

Amino Acid Sequence↗
PubMed1988

A single 12.5-kilobase androgen-regulated mRNA encoding multiple proline-rich polypeptides in the ventral prostate of the rat.

Synthetic 32P-labeled oligonucleotides have been used to identify the prostatic proline-rich polypeptide (PRP) mRNA which has partially been characterized. The 14-mer d(G-G-T-T-C-T-G-C-A-T-A-A-T-G) complementary to the coding sequence for His-Tyr-Ala-Glu-Pro, a sequence element occurring in all 38-residue PRP variants, hybridizes specifically with a 12.5-kilobase mRNA which is clearly androgen-controlled. This oligonucleotide was used as an efficient primer for the construction of a PRP-specific lambda gt10 cDNA library. The nucleotide sequence of the inserts from several recombinant clones has been determined. This structural analysis revealed a PRP mRNA encoding a large precursor containing a number of tandemly repeated units. Each repeat codes for a sequence of 100 amino acids in which the highly conserved PRP sequence is embedded. From this polyprotein the large number of PRP variants must be generated by a post-translational processing mechanism which is still unknown. The high degree of conservation of both nucleotide and amino acid sequence in the entire unit also indicates that the PRP gene(s) likely evolved by multiplication of a 300-base pair ancestral DNA sequence. This has resulted in a noninterrupted repetitive DNA coding segment which is detected at the genomic level.

Amino Acid Sequence↗
PubMedDate not supplied

[Human epiphyseal concrements in schizophrenia].

The epiphysis is a gland containing firm extracellular bodies (brain sand) the number of which increases with age. Microscopy and roentgen microtomography showed that in some cases of schizophrenia the amount of brain sand decreases. In parallel, cytoplasm of pinealocytes appears to contain concrements of a new type--irregular hollow spheres of 0.1-1.5 microm in size. They may contain fluoride. Typical hydroxyapatite retaining organic stroma may dissolve starting from the center both in health and schizophrenia.

Adult↗