Search PubMed⌕ Search

Biomedical subjects

C Lundsteen

Publications and source records attributed to C Lundsteen.

At least 73 records · Page 4Linked to original sources
PubMed1983

Interstitial deletion in the "critical region" of the long arm of the X chromosome in a mentally retarded boy and his normal mother.

A family in which an intestitial deletion of the X chromosome, del(X)(q13q21.3), is segregating was ascertained through a boy with cleft lip and palate, agenesis of the corpus callosum, and severe mental retardation. The possible causal relationship to his chromosome abnormality is discussed. Although the deletion occurred within the critical region, the mother showed no signs of gonadal dysgenesis. A phenotypically normal daughter was, as her mother, monosomic for this region of the X, and both showed random inactivation of the X chromosome.

Abnormalities, Multiple↗
PubMed1981

Aneuploidy as a marker for carcinoma-in-situ of the testis.

A microspectrophotometric study of the DNA content of carcinoma-in-situ germ cells in the testes of eight infertile men revealed an aneuploid DNA distribution pattern. The results support the assumption that carcinoma-in-situ germ cells are of a malignant nature. The findings also indicate that the DNA content can be used to discriminate between carcinoma-in-situ germ cells and spermatogonia.

Aneuploidy↗
PubMed1981

A 5;7, 5;12 double reciprocal translocation in a normal mother and a 5;7 translocation with a recombinant chromosome 5 in her normal child.

A phenotypically normal mother had two apparently balanced translocations involving chromosomes 5, 7, and 12. Her karyotype was 46,XX,t(5;7) (5;12) (p14q34;p14;q21), while her daughter, who was also phenotypically normal, had inherited only one of the translocations. Her karyotype was 46,XX,-5,-7,+rec(5)t(5;7) (q34;p14)mat,+der(7)t(5;7) (q34;p14)mat. The other was lost during a meiotic crossing over, giving the daughter an apparently balanced chromosome complement.

Adult↗
PubMed1981

A complex four-break rearrangement between chromosomes 4 and 13 resulting in a recombinant chromosome 4.

A complex four-break rearrangement between chromosomes 4 and 13 was ascertained in a 10-year-old mentally retarded girl. The rearrangement was inherited from the phenotypically normal mother, who had an inverted insertion of part of the long arm of chromosome 4 into the long arm of 13 and, in addition, a pericentric inversion of the deleted 4. Meiotic crossing-over between the normal and the inverted 4 resulted in a recombinant chromosome 4, which was inherited by the proband, together with the 13/4 insertion. In this way the proband became monosomic for 4q35 leads to qter and trisomic for 4pter leads to 4p15, but she showed only minor physical malformations, as compared with other reports on the trisomy 4p syndrome. The cytogenetic findings are difficult to describe using the ISCN nomenclature.

Chromosome Aberrations↗
PubMed1981

Automatic chromosome analysis. II. Karyotyping of banded human chromosomes using band transition sequences.

Human chromosomes, represented by band transition sequences, chromosome area, centromeric index by area and centromeric index by density, were karyotyped by computer. A reference set of chromosomes provided frequencies of occurrence of each density class and difference class of the band transition sequence as well as of each of the three global features. The karyotyping program was designed to handle all metaphases, even those from which severely bent and overlapped chromosomes were excluded. In one experiment, 21 metaphases were karyotyped on the basis of a reference set and the results were compared with earlier results of visual analysis of band transition profiles developed from band transition sequences: 0.8% errors were made in the visual experiment and 1.4% errors were made in the computer based experiment. In a second experiment, 179 metaphases were divided into reference and test sets and karyotyped by computer with an error rate of 3.4%. By further analysis it was found that metaphases with many misclassified chromosomes could often be automatically distinguished from metaphases with few errors. Thus by automatic rejection of 7% of the metaphases the error rate could be reduced to 2.6%. The computer program for chromosome karyotyping will now be implemented in a semi-automatic system for practical clinical chromosome analysis.

Chromosome Banding↗
PubMed1980

Quantitative analysis of 6985 digitized trypsin G-banded human metaphase chromosomes.

The frequency and staining intensity of the dark bands were measured in 6985 trypsin G-banded human chromosomes, described by so-called band transition sequences which represent the chromosome banding patterns in a condensed quantitative way. In the haploid chromosome complement a maximum of 351 bands were registered: 181 white and 170 dark bands. The frequency with which bands occurred and the staining intensity of the bands differed considerably between the chromosome types. Among the dark bands the darker stained bands occurred more frequently than the lighter stained bands. A study of the relationship between the degree of chromosome contraction and the frequency of band occurrence revealed that for all chromosome types the average band frequency increased with increasing chromosome elongation. Twenty of the 23 dark bands chosen as landmarks by the Paris Conference (1971) occurred with high frequency and staining intensity. The remaining three landmarks occurred less frequently, due to fusion of dark and white bands, respectively. A study of global features showed, as expected, good agreement between chromosome length, area and density. there was good agreement between the centromeric indices determined by length and area, respectively, and no difference was found between contracted and elongated chromosomes, with the exception of the acrocentrics where elongated chromosomes showed higher centromeric indices than contracted chromosomes. Most often, the centromeric index by density differed considerably from the centromeric indices by length and area, respectively. The data presented here may be used in clinical cytogenetics as a supplement to the ISCN idiograms (ISCN 1978), as the band frequencies and staining intensities may help in identifying and characterizing specific bands.

Chromosome Banding↗
PubMed1980

Automatic chromosome analysis. I. A simple method for classification of B- and D-group chromosomes represented by band transition sequences.

This paper describes an approach to the automatic analysis of banded B- and D-group chromosomes, represented by band transition sequences (BT-sequences), using Bayes formula in a simple way. The analysis considers the 14 BT-codes constituting the BT-sequence as being independent variables. Error rates of 6-8% in classification experiments and 3-4% in karyotyping experiments are clearly smaller than those reported by other authors using other methods. If the error rates of karyotyping are adjusted for errors in the basic material, they are reduced to 2-3%. The reason for the small error rate is presumably that the BT-sequences are superior to other methods for condensed band-pattern description. The method will be incorporated into a programme system for automatic karyotyping.

Chromosome Banding↗
PubMed1979

Prader-Willi syndrome and chromosomal mosaicism 46,XY/47,XY,+mar in two cases.

Two cases of the Prader-Willi syndrome with 46,XY/47,XY,+mar are reported. The majority of Prader-Willi patients with chromosome abnormalities have either 15/15 translocations or mosaicism. Both of these aberrations presumably occur after fertilization. A possible relationship between high parental age and chromosome abnormalities in the Prader-Willi syndrome is discussed.

Child↗
PubMed1979

Description of chromosome banding patterns by band transition sequences: a new basis for automated chromosome analysis.

For visual and automated analysis of banded human chromosomes, the band pattern features of chromosome profiles considered essential for the cytogeneticist were evaluated. These features were found to be related to each peak (dark band) and its adjacent valley (light band) in the direction p--q. A method for extracting and describing these features was developed and implemented on a computer. The method determines three normalized parameters for each peak and adjacent valley: (1) density of peak; (2) density difference (transition) between peak and valley; and (3) position of peak. Each profile is described by a simple sequence of band transitions (BT-sequence). The BT-sequence was visualized as a profile (BT-profile) using only the information retained in the BT-sequence. Visual classification of BT-profiles shows error rates comparable to visual classification of ordinary density profiles (Lundsteen & Granum 1979). It is therefore concluded that the BT-profiles do retain the important band pattern features of the profiles, and it is supposed that the simple and condensed BT-sequences constitute an appropriate basis for automated karyotyping.

Chromosome Banding↗
PubMed1979

Visual classification of banded human chromosomes. III. Classification and karyotyping of density profiles described by band transition sequences.

Band transition profiles (BT-profiles) representing extracted band pattern features of 898 density profiles of banded chromosomes were classified and karyotyped by a cytogeneticist in order to investigate how much information was lost by substituting for the original density profiles their extracted features. The results were evaluated and compared with visual classification and karyotyping of the same 898 density profiles from which the BT-profiles were derived. Six per cent errors were made in classification of isolated BT-profiles and 0.7% errors were made in karyotyping BT-profiles. These error rates were comparable to the corresponding error rates in classifying and karyotyping density profiles, which were 5% and 0.5%, respectively. It is concluded that most of the important band pattern information of the density profiles is retained in the BT-profiles, and it is supposed that the condensed BT-sequences (from which the BT-profiles are derived) constitute a sufficient and appropriate basis for automated karyotyping.

Chromosome Banding↗
PubMed1977

Visual classification of banded human chromosomes ii. classification and karyotyping of integrated density profiles.

Visual classification and karyotyping of 897 integrated density profiles generated from straight and non-overlapping chromosomes from 22 trypsin-banded metaphases of average quality was carried out and evaluated. The results were compared with visual classification of photographic prints of the same 897 chromosomes. The experiments were carried out by one observer. About 5% errors were made in classification of isolated profiles; 0-5% errors were made in karyotyping profiles and about 3% errors were made in classification of isolated chromosome prints. The reason for the small error rate obtained by karyotyping profiles as compared to the error rate when classifying isolated profiles was assumed to be the use of a priori knowledge of the composition of (normal) metaphases and the possibility of making appropriate comparisons between the individual profiles within the metaphase. Comparison between classification of isolated prints and of profiles showed different error patterns on the basis of which it was assumed that prints constitute a better basis for visual classification than profiles. The results seemed to indicate two ways of improving computer classification of banded chromosomes: (1) information of value in the chromosomes (band pattern, shape etc.) should be extracted from the digitized chromosome image in a manner superior to the simple integration by which profiles are produced; (2) computer karyotyping should simulate the human method, thus taking advantage of a priori knowledge of the composition of the metaphases and being able to make appropriate comparisons between individual chromosomes.

Chromosomes↗
PubMed1977

Indication of primary immune deficiency in Fanconi's anemia.

A girl with various congenital malformations developed pancytopenia and hypoplastic bone marrow at the age of 6 year. A chromosome study of lymphocytes showed numerous breaks, gaps and rearrangements, allowing the diagnosis of Fanconi's anemia. Treatment with corticosteroids and splenectomy did not result in hematologic remission. Repeated immunologic studies showed increasingly deficient T cell function as judged by lymphocyte transformation studies and skin test reactivity, whereas T cell number, T/B cell ratio, immunoglobulins, complement factors and neutrophil function were normal. A sever Pneumocystis carinii pneumonitis developed, but was successfully treated with pentamidine, sulfametoxazole with trimetoprim and transfer factor. Improvement of T cell function followed transfer factor therapy. Combined therapy with corticosteroids and androgens caused partial remission of the hematologic abnormalities. The probability of a primary immune deficiency in the patient is discussed.

Abnormalities, Multiple↗
PubMed1977

Trisomy 8 syndrome. A psychological and somatic study of a mentally non-retarded male with 46,XY/47,XY,+8 chromosome constitution.

A 27-year-old, non-retarded male with trisomy 8 mosaicism (46,XY/47,XY,+8) had a short head, a short broad-bridged nose, a protruding upper lip, pterygium colli, moderate kypho-scoliosis, camptodactyly of all fingers and deep furrowing on the soles. Radiographic examination of columna showed spina bifida of L1 and fusion of L5 and S1. These findings are characteristic for the trisomy 8 syndrome. A psychological study showed a personality characterized by immaturity and lack of spontaneity and self-confidence. An intelligence test (WAIS) placed him within the normal range, but presented an uneven development of the cognitive functions with special difficulties in synthetic abilities and visual scanning. His auditive span was rather low, and his memory functions were somewhat below average.

Abnormalities, Multiple↗