Establishment of a human carcinoembryonic antigen-producing colon adenocarcinoma cell line.
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A human carcinoembryonic antigen-producing colon carcinoma cell line has been established. The cells form acinar structures and signet ring cells. The lumen of the acini presents microvilli and a glycocalyx. Neighboring cells show desmosomes and terminal bars. The cells present an aneuploid karyotype with a modal number of 49. No marker chromosomes are found, although a significant proportion of cells show an altered A2 chromosome and an extra B. Exponentially growing cultures produce 54 ng of carcinoembryonic antigen/10(6) cells. Kinetic parameters are as follows: doubling time, 37 hr; mitotic index, 0.8%; labeling index, 31%; generation time, 30 hr; G1 phase, 7 hr; S phase, 18 hr; G2 phase, 5 hr; growth fraction 90%. This cell line, designated line LoVo, represents an in vitro model for human colon carcinoma. (+info)
Reciprocal translocation, 4q-; 21p+, giving rise to Down's syndrome.
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A reciprocal translocation is described, t(4;21)(q27;p11), which occurs in a balanced carrier mother and her Down's syndrome child, 47,XX,t(4q-;21p+),+21. A review is presented of Down's syndrome associated with reciprocal translations involving chromosome No. 21. (+info)
Nature of telomere dimers and chromosome looping in human spermatozoa.
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Specific and well-organized chromosome architecture in human sperm cells is supported by the prominent interactions between centromeres and between telomeres. The telomere-telomere interactions result in telomere dimers that are positioned at the nuclear periphery. It is unknown whether composition of sperm telomere dimers is random or specific. We now report that telomere dimers result from specific interactions between the two ends of each chromosome. FISH using pairs of subtelomeric DNA probes that correspond to the small and long arms of seven human chromosomes demonstrates that subtelomeres of one chromosome are brought together. Statistical analysis confirmed that telomere associations could not result from the random proximity of DNA sequences. Therefore, chromosomes in human sperm nuclei adopt a looped conformation. This higher-order chromosome structure is most likely required for chromosome withdrawal/decondensation during the early fertilization events leading to zygote formation. (+info)
Association of three genetic loci with uric acid concentration and risk of gout: a genome-wide association study.
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Locus for familial migrainous vertigo disease maps to chromosome 5q35.
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OBJECTIVES: Migrainous vertigo (episodic vertigo associated with migraine) is sometimes inherited as an autosomal dominant trait. However, neither disease genes nor loci that might be responsible have been reported. We sought to map the genetic locus for familial migrainous vertigo in a 4-generation family and to define the progression of disease in this family. METHODS: We studied 23 members in a family in whom migrainous vertigo was inherited as an autosomal dominant trait. Clinical information obtained included case histories and results of otolaryngological, neurologic, audiometric, and imaging evaluations. Genome-wide linkage analysis was performed with Affymetrix Genechip Human Mapping 10K microarrays. Genotyping of family members' DNA with microsatellite markers was used to further assess candidate loci identified from the whole-genome scan. RESULTS: Of 23 family members, 10 suffered from migrainous vertigo beginning after 35 years of age. Migraine headaches usually preceded the onset of vertigo by 15 to 20 years. Longitudinal audiometric studies over 12 years showed stable, high-frequency sensorineural hearing loss consistent with presbycusis. Low-frequency or fluctuating hearing loss was not observed. The results of vestibular testing and imaging studies were unremarkable. Genetic analysis defined a 12.0 MB interval on chromosome 5q35 between loci rs244895 and D5S2073 that contained the disease gene (logarithm of odds score, 4.21). CONCLUSIONS: We report the first locus for familial migrainous vertigo, which mapped to 5q35. (+info)
Sequence variations in the 5' flanking and IVS-II regions of the G gamma- and A gamma-globin genes of beta S chromosomes with five different haplotypes.
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We have amplified and sequenced the 5' flanking and the second intervening sequence (IVS-II) regions of both the G gamma- and A gamma-globin genes of the beta S chromosomes from sickle cell anemia (SS) patients with homozygosities for five different haplotypes. The sequencing data, compared with previously published sequences for the normal chromosomes A and B, show many similarities to chromosome B for haplotypes 19, 20, and 17, while haplotypes 3 and 31 are remarkably similar to chromosome A and also similar to each other. Several unique mutations were found in the 5' flanking regions (G gamma and A gamma) of haplotypes 19 and 20 and in the IVS-II segments of the same genes of haplotypes 19, 20, and 17; the IVS-II of haplotypes 3 and 31 were identical to those of chromosome A. Dot-blot analyses of amplified DNA from additional SS patients with specific probes have confirmed that these mutations are unique for each haplotype. The two general patterns that have been observed among the five haplotypes have most probably arisen by gene conversion events between the A and B type chromosomes in the African population. These patterns correlate with high and low fetal hemoglobin expression, and it is speculated that these and other yet unknown gene conversions may contribute to the variations in hemoglobin F and G gamma levels observed among SS patients. In vitro expression experiments involving the approximately 1.3-kb 5' flanking regions of the G gamma- and A gamma-globin genes of the beta S chromosomes with the five different haplotypes failed to detect differences between the levels of expression, suggesting that the sequence variations observed between these segments of DNA are not the primary cause of the differences in hemoglobin F levels among the SS patients. (+info)
HPV type-related chromosomal profiles in high-grade cervical intraepithelial neoplasia.
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In vitro culture of leukemic cells in t(4;11) acute leukemia.
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In the present study we utilized a semisolid culture system with feeder cells and enriched media to evaluate the growth of acute leukemia associated with the 4;11 chromosomal translocation. We compared growth of t(4;11) leukemia to typical acute nonlymphocytic leukemia (ANL) and acute lymphocytic leukemia (ALL). The two cases of t(4;11) leukemia tested exhibited the highest cloning efficiency of cells tested. The growth characteristics of t(4;11) leukemia were more similar to ANL than ALL. (+info)