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Biomedical subjects

V Beensen

Publications and source records attributed to V Beensen.

16 recordsLinked to original sources

Insulin-like growth factor serum concentrations reflect insufficient growth in a hypoplastic infant with partial trisomy 9q in the 12th week of life.

This report presents changes of IGFs and IGFBPs in a female infant with partial trisomy 9q in the 12th week of life. Studying deficient growth in this hypoplastic infant (birth weight 1405 g, birth length 36 cm) with dysmorphic features, the following changes in IGFs and IGFBPs were detected (microg/l): IGF-I: 26.5 vs 48.1 in healthy infants; IGF-II: 420 vs 728; IGFBP-2: 931 vs 524; IGFBP-3: 800 vs 1070. This demonstrates that IGFs and IGFBPs may reflect individual insufficient growth even at this early age.

Adult↗

Maternal UPD 20 in a hyperactive child with severe growth retardation.

Maternal uniparental disomy was observed in a 4-year-old boy with severe pre- and postnatal growth retardation (body height: 85 cm = 12 cm < third percentile, head circumference: 48 cm = 10 cm < third percentile), a few minor facial findings, and with apparent hyperactivity. His intelligence is within the normal range for his age. Karyotype analysis revealed two cell lines, one apparently normal with 46,XY, the other with a tiny marker (47,XY, + mar). Microdissection and reverse chromosome painting using the marker DNA library as a probe, as well as PCR analysis revealed that the marker is from chromosome 20 and contains only the centromere and pericentromeric segments, but none of the pericentromeric loci for microsatellites. Microsatellite analysis of 25 chromosome 20 loci disclosed maternal uniparental disomy for all 16 informative markers. Maternal heterodisomy was evident for seven loci of the short arm segment 20p11.2-pter. Maternal isodisomy was found at five loci, three of them map to the proximal 20p11.2 segment and two to 20q. To our knowledge, this is the first case of maternal disomy 20 in humans.

Child Behavior Disorders↗

Translocation trisomy dup(21q) and free trisomy 21 can be distinguished by interphase-FISH.

The possibility of distinguishing in routine diagnostics translocation trisomy dup(21q) from disomy 21 as well as from free trisomy 21 using interphase fluorescence in situ hybridization (FISH) with a single copy probe (LSI 21) localized on chromosome 21q22.13-q22.2 is described. In free trisomy 21 and translocation trisomy dup(21q) 94%-98% of the nuclei exhibit 3 specific signals, while in disomy 21 only up to 6% of them have 3 false positive signals. Furthermore, reliable differentiation between free and translocation trisomy dup(21q) can be achieved by evaluating the percentage of nuclei with one single and two co-localized chromosome 21q22.13-q22.2 specific signals in 50-100 interphase nuclei. While in translocation trisomy 75+/-4.3% are co-localized due to a chromosomal rearrangement, in free trisomy 21 only 40+/-2.83% of the nuclei have two co-localized signals by chance. No differences in interphase signal distribution could be detected in two cases with a dicentric chromosome dup(21q) compared to one case with a monocentric one, a comparison not previously carried out. In addition, the single copy probe LSI 21 was compared with the alphoid probe D13Z1/D21Z1 which was found to be unsuitable for such assays due to polymorphisms in the á satellite regions of chromosome 21.

Amniotic Fluid↗

Molecular cytogenetic characterization of a prenatally detected supernumerary minute marker chromosome 8.

The characterization of a prenatally detected very small (approximately half of 18p-(karyotype: 47,XX,+mar[16]/46,XX[7]) supernumerary marker chromosome (SMC) identified by GTG-banding analysis is described. The marker has been identified as derived from chromosome 8 centromeric material using a combination of different cytogenetic (GTG-, NOR-, CBG banding), molecular cytogenetic (24 colour-fluorescent in situ hybridization [FISH], three-colour FISH using centromeric probes for all human chromosomes) and molecular genetic techniques (microsatellite analysis). This is the first case described with such a minute SMC derived from chromosome 8 diagnosed prenatally, the 15th case reporting on a SMC originating from chromosome 8 and the third such case without any severe clinical features.

Adult↗

Interstitial deletion of chromosome 6q: precise definition of the breakpoints by microdissection, DNA amplification, and reverse painting.

Routine chromosomal analysis using GTG-banding alone showed a mosaic terminal deletion of 6q in a 14-week-old boy with developmental retardation, facial anomalies, agenesis of corpus callosum, cleft palate, hypotonia, short neck and pterygium colli, and minor anomalies of hands and feet. Discrepancies between the clinical findings on our patient and those described in the literature on patients having terminal deletions led to a more precise analysis of the karyotype. Reverse painting was performed on normal G-banded metaphases for exact determination of the breakpoints and on metaphases of the patient for evaluation of mosaicism. A DNA library that was obtained by microdissection of three deleted chromosomes 6 was used as a painting probe. Subsequent DNA amplification was performed with the help of topoisomerase-pretreated degenerate oligonucleotide primers. Unexpectedly, the hybridization pattern on normal metaphase chromosomes revealed an interstitial deletion with breakpoints at 6q25.1 and 6q27 instead of a terminal deletion. Hybridization on metaphases of the patient showed one deleted chromosome 6 in all metaphases analyzed at a higher resolution rather than mosaicism as previously assumed [karyotype, 46,XY,del(6)(q25.1 --> q27)]. We assume that in the single cases of 6q- described in the literature the deletions are misclassified. This might be due to difficulties in distinguishing between interstitial and terminal deletions at 6q and in precisely defining chromosomal breakpoints after GTG-banding alone.

Abnormalities, Multiple↗

[Complete trisomy 22].

In a 2 6/12-years-old girl a complete trisomy 22 was verified with the G-banding (CTG-technique). She presented with Pierre-Robin-Sequence, cardiac and renal malformations, craniofacial dysmorphia and psychomotoric retardation as it often occurs in trisomy 22. Additionally, we observed tonic-clonic seizures, remarkable dumbles on both elbows and a clavicular anomaly.

Abnormalities, Multiple↗

[Fetal triploidy--diagnosis and sequelae].

A pregnancy in the 22nd week of gestation with severe asymmetric retardation of growth without malformations by ultrasonography is described. A triploidy was found by prenatal cytogenetic investigation. Possible signs for triploidy in pregnancy and the necessary conclusions are discussed.

Abnormalities, Multiple↗

[The Ro/SSA antigen-antibody system. Studies of the effect of UVA-/PUVA irradiation and fibroblast activity on immune reaction with autoantibodies].

The Ro/SSA antigen-antibody system is of great importance with regard to the cutaneous manifestations and the photosensitivity of patients suffering from lupus erythematosus (LE). On account of in vitro investigations on cultured fibroblasts taken from psoriatic skin, we evaluated both the effect of UVA/PUVA irradiation and that of the metabolic activity of cells on this antigen-antibody system. We found that UVA irradiation is able to demask Ro/SSA. Thus it becomes accessible so subsequent antibody binding, which can be seen as nuclear fluorescence positive for IgM. Incubation of vital cells with these autoantibodies and subsequent irradiation resulted in a high degree of cytoplasmic fluorescence (IgG, IgM) in part of the fibroblasts exposed to UVA. Regarding the clinical application of light protective agents in LE patients with antibodies to Ro/SSA, UVA light--aside from UVB--should be taken into consideration.

Antibodies, Antinuclear↗

Differential effects of treatment with UV-light (365 nm) and 8-methoxypsoralen on chromosomes of healthy persons and psoriatic patients.

The effect of 8-methoxypsoralen (8-MOP, 5 X 10(-5) M), near UV-light of 365 wavelength (UVA, 1.5 J/cm2) and the combination of both (PUVA treatment) were studied on lymphocytes in vitro taken from healthy persons and patients with psoriasis vulgaris and psoriasis arthritis (psoriasis arthropathica). Chromosomes isolated from cell nuclei were visualized by means of Giemsa staining technique and analyzed for induction of chromosomal defects, i.e. premature centromere division (PCD), major coiling (MC), and formation of gaps and fragile sites. Exposure of nonpsoriatic lymphocytes to 8-MOP, UVA or PUVA increased the rate of PCD or MC generation. In experiments with psoriatic lymphocytes a much weaker effect was found, with a moderate increase of PCD and MC after UVA or PUVA treatment in the case of psoriasis vulgaris, and of MC after UVA treatment of psoriasis arthritis. On the average the number of chromosomes per metaphase plate displaying PCD did not exceed 10. No indication was obtained for the preference of certain chromosome groups or the appearance of "fragile sites". Under all experimental conditions the number of chromosome gaps ranged in the order of their spontaneous induction. Our findings suggest PCD and MC investigations as possible sensitive tools for diagnosing latent psoriasis and for refined analysis of psoriatic cells or chromosomes. However, more experiments along this line are needed.

Chromosomes, Human↗