Search PubMed⌕ Search

Biomedical subjects

C M Strom

Publications and source records attributed to C M Strom.

44 records · Page 3Linked to original sources

Isolation and characterization of genomic clones corresponding to the human type II procollagen gene.

A recombinant human DNA library was screened using probes corresponding to the chick alpha 1 (II) procollagen gene. This resulted in the isolation of 2 different genomic clones, LgHCol(II)a and LgHCol(II)b. LgHCol(II)a was identified as corresponding to the alpha 1(II) gene by comparative hybridization and DNA sequence analysis. DNA sequence established that LgHCol(II)a extends at least from amino acid 694 of the triple helix through 54 amino acids of the COOH-propeptide. Hybridization with a probe containing only the exon at the 3' end of the chicken gene suggests that the clone contains the 3' end of the human gene. Thus LgHCol(II)a contains approximately 40% of the coding sequences of the human type II collagen gene.

Amino Acid Sequence↗

Localization of human type II procollagen gene (COL2A1) to chromosome 12.

DNA was prepared from 39 human-mouse somatic cell hybrid lines, and mouse and human parental cell lines. The DNA was digested to completion with EcoRI and Southern filters were prepared. These filters were hybridized at high stringency conditions to the human genomic subclone phHCol(II) A which corresponds to the human alpha 1(type II) procollagen gene (COL2A1). The mouse DNA yielded a single band at greater than 10 kb, whereas the human DNA had the expected single band at 4.8kb. Analyses of these human-mouse cell hybrids demonstrated that the human alpha 1(type II) procollagen gene segregates with chromosome 12.

Chromosome Mapping↗

Hypoplastic pulmonary arteries and aorta with obstructive uropathy in 2 siblings.

Two sisters who presented with diffuse hypoplasia of pulmonary arteries, relative hypoplasia of ascending aorta, obstructive uropathy, bilateral ureteral reflux, and hydronephrosis, are described. The subsequent course was characterized by progressive and gradual onset of right heart failure, failure to thrive, chronic malabsorption and systemic hypertension. The syndrome which appears to be transmitted by autosomal recessive inheritance can possibly represent a generalized hypoplasia and growth failure of a part or the entire arterial system. Peripheral pulmonary stenosis can occur as an isolated lesion or in association with other congenital cardiac anomalies, as well as in rubella syndrome and the syndrome of supravalvular aortic stenosis. This communication reports two siblings with a hitherto unreported combination of hypoplastic pulmonary arteries, and aorta with identical genito-urinary tract abnormalities.

Abnormalities, Multiple↗

Amplification of DNA sequences during chicken cartilage and neural retina differentiation.

[3H]BrdUrd-substituted DNA probes were prepared from organ cultures of differentiating chicken neural retina and cell cultures of stage 24 chicken limb buds. Reassociation reactions using the neural retina probe demonstrated amplification of DNA sequences during differentiation of neural retina. This probe also contained sequences present in greater numbers in heart DNA than in DNA from undifferentiated neural retina. Reassociation reactions of both differentiated cartilage and differentiated neural retina DNA with both the neural retina probe and the cartilage probe demonstrated that at least part of the amplified sequences are tissue specific.

Animals↗

Amplification of moderately repetitive DNA sequences during chick cartilage differentiation.

A 5-bromo-2'-[3H]deoxyuridine (BrdUrd) probe was isolated to analyze DNAs obtained from various chick tissues and cell types. [3H]BrdUrd-substituted DNA, prepared from limb bud cultures, was sheared and freed from palindromic DNA. Nonradioactive DNA was prepared from embryonic liver, undifferentiated limb bud mesenchyme, sternal cartilage, differentiated limb bud cultures, and BrdUrd-blocked cultures, and was sheared. These DNAs were used in 100-fold excess to drive the reassociation of the [3H]-BrdUrd-DNA probe. Purified mature cartilage DNAs of embryonic sternae or differentiated limb bud cultures drove the reassociation of the probe approximately two times faster than did DNA from liver, undifferentiated limb bud, or BrdUrd-blocked cells. These data indicate that cartilage DNA contains a greater number of sequences complementary to the BrdUrd probe than do DNAs of noncartilage or undifferentiated precartilage cells. Calculations determined an average substitution of 10% of thymidine residues by BrdUrd in purified probe, whereas CsCl density gradients of unsheared probe revealed radioactive peaks of greater than 20% substitution. The BrdUrd appears to be clustered in the genome.

Alleles↗

Distribution of 5-bromodeoxyuridine and thymidine in the DNA of developing chick cartilage.

In order to study the mechanism of the irreversible effects of BrdUrd on the differentiation of limb bud mesenchyme to cartilage, the reannealing behavior of DNA obtained from such cells was examined. Cells incubated with [3H]thymidine ([3H]dThd) during days 1 and 2 of culture incorporated label into repetitive, moderately repetitive, and unique classes of DNA. In contrast, when 5-bromo-2'-[3H]deoxyuridine ([3H]Brd Urd) was added during the first 48 hr (in the presence of 32 muM BrdUrd), the label was preferentially incorporated into a late moderately repetitive region. Simultaneous incubation of unlabeled BrdUrd and [3H]dThd revealed a selective inhibition of [3H]dThd incorporation into moderately repetitive regions. Cultures incubated during days 3 and 4 with [3H]dThd incorporated label into all three classes of DNA; however, when [3H]dThd was present during days 3 and 4 in cultures previously incubated with BrdUrd during days 1 and 2, the [3H]dThd was incorporated preferentially in the late moderately repetitive region. The melting behavior of this reannealed DNA was identical with that of the reannealed 1-2 day [3H]BrdUrd-labeled, late moderately repetitive DNA. Turnover experiments revealed that whereas there was no loss of [3H]deoxycytidine or [3H]dThd, 37% of [3H]BrdUrd activity was lost from the DNA in 2 days after removal of the isotopes.

Animals↗

Genotype-phenotype correlation and frequency of the 3199del6 cystic fibrosis mutation among I148T carriers: results from a collaborative study.

PURPOSE: We expect that the mutation panel currently recommended for preconception/prenatal CF carrier screening will be modified as new information is learned regarding the phenotype associated with specific mutations and allele frequencies in various populations. One such example is the I148T mutation, originally described as a severe CF mutation. After implementation of CF population-based carrier screening, we learned that I148T exists as a complex allele with 3199del6 in patients with clinical CF, whereas asymptomatic compound heterozygotes for I148T and a second severe CF mutation were negative for 3199del6. METHODS: We performed reflex testing for 3199del6 on 663 unrelated specimens, including I148T heterozygotes, compound heterozygotes, and a homozygous individual. RESULTS: Less than 1% of I148T carriers were also positive for 3199del6. Excluding subjects tested because of a suspected or known CF diagnosis or positive family history, 0.6% of I148T-positive individuals were also positive for 3199del6. We identified 1 I148T homozygote and 6 unrelated compound heterozygous individuals with I148T and a second CF variant (2 of whom also carried 3199del6). In addition, one fetus with echogenic bowel and one infertile male were heterozygous for I148T (3199del6 negative). CONCLUSIONS: Reflex testing for 3199del6 should be considered whenever I148T is identified. Reflex testing is of particular importance for any symptomatic patient or whenever one member of a couple carries a deleterious CF mutation and the other member is an I148T heterozygote. Further population data are required to determine if I148T, in the absence of 3199del6, is associated with mild or atypical CF or male infertility.

Cystic Fibrosis↗