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A V Carrano

Publications and source records attributed to A V Carrano.

At least 19 recordsLinked to original sources
PubMed1992

Order and genomic distances among members of the carcinoembryonic antigen (CEA) gene family determined by fluorescence in situ hybridization.

Fluorescence in situ hybridization was used to establish the order of, and to estimate genomic distances among, members of the carcinoembryonic antigen (CEA) and pregnancy-specific glycoprotein (PSG) subgroups on chromosome 19. Fluorescence in situ hybridization to metaphase chromosomes localized the PSG subgroup telomeric to the CEA subgroup. Cosmid clones containing sequences for individual genes in the CEA and PSG subgroups were also hybridized to human sperm pronuclear and somatic interphase nuclear chromatin targets. The mapping results lead to the gene order cen-CGM7-CEA-NCA-CGM1-BGP-CGM9-CGM8-PSG-te l. The genomic distances between selected pairs of gene family members were estimated from the physical distances between hybridization sites measured in pronuclei. The CEA-PSG gene family region is estimated to span 1.1 to 1.2 Mb.

Carcinoembryonic Antigen↗
PubMed1979

Transcription and hybridization of 125I-cRNA from flow sorted chromosomes.

Metaphase chromosomes from the Chinese hamster cell line M3-1 were separated by means of a flow sorter. Two chromosome fractions were used for this study: A, which consisted of 95% pure chromosome no. 1, and B, which was 90% pure chromosome no. 2. The DNA of 10(6) chromosomes of each type was purified, and a 125I-cRNA transcript was synthesized in a reaction containing E. coli RNA polymerase and carrier-free 125I-CTP (1.7 Ci/mumole). The cRNA product synthesized with template DNA from 10(5) sorted chromosomes contained more than 10(6) dpm. The electrophoretic mobility profiles of the cRNAs on 7.5% SDS acrylamide gels demonstrated that more than 50% of the ribo-polymers were equal to or longer than marker E. coli met-tRNAf. In hybridization reactions 21% and 17% of the transcripts from Chinese hamster whole cell and sorted chromosome DNA hybridized to Chinese hamster DNA and did not hybridize significantly over background in reactions containing calf DNA at Crt values of 1.3 and 1.9 x 10(2) mole sec/l. Labelled cRNAs transcribed from the DNA of sorted chromosomes hybridized with the DNA of each sorted chromosome fractions at a Crt of 0.6 mole sec/l. This study demonstrated that the DNA can be (1) recovered from small numbers of highly purified flow sorted chromosomes, (2) used as template by E. coli RNA polymerase and (3) used to prepare a cRNA in reactions containing polymerase and carrier-free 125I-CTP to yield a product which can be employed for hybridization analysis.

Animals↗
PubMed1979

DNA crosslinking, sister-chromatid exchange and specific-locus mutations.

Chinese hamster ovary cells were treated with the DNA-crosslinking chemicals, mitomycin C (MMC) and porfiromycin (POR), and their monofunctional derivative decarbamoyl mitomycin C (DCMMC). After exposure, the cells were studied for the induction of sister-chromatid exchanges (SCEs) and mutations at the hypoxanthine phosphoribosyltransferase and adenine phosphoribosyltransferase loci. The frequency of SCEs varied significantly in successive sampling intervals, requiring the weighting of each interval by the percentage of second-division mitosis in that interval to obtain the mean SCE frequency for each dose. All 3 compounds were potent inducers of SCEs but weakly mutagenic. All 3 chemicals by concentration were approximately equally effective in inducing SCEs or mutations. When the induced SCEs and mutations were compared at equal levels of survival, DCMMC was slightly more effective than MMC or POR in inducing SCEs and somewhat less mutagenic. These results indicate that the DNA interstrand crosslink is not the major lesion responsible for the induction of SCE or mutation by these compounds.

Adenine Phosphoribosyltransferase↗
PubMed1979

Assignment of human beta-, gamma-, and delta-globin genes to the short arm of chromosome 11 by chromosome sorting and DNA restriction enzyme analysis.

Normal human metaphase chromosomes isolated from fibroblasts were resolved into 14 peaks based on total Hoechst 33258 fluorescence and sorted with the fluorescence-activated cell sorter. The chromosomal DNA was extracted and characterized by EcoRI analysis. As expected, analysis of the peak containing chromosomes 16 and 18 detected the alpha-globin genes and of the peak containing chromosomes 9, 10, 11, and 12 detected the beta-, gamma-, and delta-globin genes. Translocations were then used to localize further the beta-, gamma-, and delta-globin genes. The first translocation t(11;22)(q25;q11), which moved nearly all of chromosome 11 to a different peak, confirmed that the beta-, gamma-, and delta-globin genes are on this chromosome. The second, t(4;11)(q25;q13), which moved the distal portion of the long arm of chromosome 11 to a new peak, showed that the genes are not in this segment. The third, t(X;11)(q11;p13), moved the distal region of the short arm of chromosome 11 to a peak which now contained the beta-, gamma-, and delta-globin genes. Therefore, the beta-, gamma-, and delta-globin genes residue on the distal portion of the chromosome 11 short arm including bands p13, p14, and p15. This sorting method may be used generally to assign other genes to chromosomal segments of the entire chromosome complement.

Cell Fractionation↗
PubMed1979

Measurement and purification of human chromosomes by flow cytometry and sorting.

The 24 human chromosome types of normal diploid fibroblast cell strain were classified into 15 groups by high-resolution flow cytometry on the basis of 33258 Hoechst fluorescence. Chromosomes associated with each group were flow sorted onto microscope slides and identified by quinacrine banding analysis. DNA cytophotometry of metaphase chromosomes from the same cell strain supported and extended this identification. Four of the groups purified were due to chromosomes of a single type--namely, chromosomes 5, 6, 13, and 17. Eight additional groups were also separated and found to contain the following chromosomes: 1 and 2; 3 and 4; 7, 8, and X; 9--12; 14 and 15; 16 and 18; 20 and Y; and 19, 21, and 22. The average purity for the 12 sorted fractions was 78%.

Cell Line↗
PubMed1979

Do homologous chromosomes differ? A preliminary investigation based on DNA measurements.

This paper is concerned with the problem of deciding whether measurements from homologous chromosomes differ. First, a general mathematical model is proposed for studying the distribution of chromosome measurements. Next, log-likelihood ratios are used to test for correlation between homolog pairs and for differences between homolog means and variances. The tests are applied to measurments on 1946 pairs of chromosomes from 10 normal individuals. Test results are interpreted taking into account the large number (2025 total tests) required by the study. Our results demonstrate that, at the current level of resolution, most homologs do not show differences in DNA content. However, there is some evidence that several homologs pairs differ by small amounts of DNA (less than 0.2% of the autosomal genome). Power studies indicate that sample sizes of 20 to 30 measurements are required to detect differences of this size.

Chromosomes, Human↗
PubMed1979

DNA measurements of mitotic chromosomes of the rabbit (Orytolagus cuniculus).

DNA cytophotometry was used to obtain the relative DNA content of mitotic chromosomes of Orytolagus cuniculus. DNA ranking of the rabbit chromosomes is presented, and related to the quinacrine and Giemsa-banded karyotype. In addition, the relative DNA content of the short and long arms of each chromosome was calculated and the DNA-based centromeric index, (i.e., the ratio of long-arm DNA to total chromosomal DNA) determined. The Y chromosome is clearly a submetacentric chromosome on the basis of the DNA measurements.

Animals↗
PubMed1979

Chromosomal DNA cytophotometry in 20q- nonspecific myeloid disorders.

DNA cytophotometry was used to quantify the chromosomal alterations in the bone marrow and blood of three patients with nonspecific myeloid disorders. All patients possessed a population of cells with a morphologically abnormal chromosome 20, del(20)(qll). In two of the patients, the abnormal chromosome 20 showed nearly identical DNA measurements with a net loss of 0.37% of the total autosomal DNA in one patient and 0.38% in the second. The third patient had a net loss of only 0.25% of the autosomal DNA. Analysis of the DNA content of the long arm and short arm of the abnormal No. 20 indicated that all three cases had chromosomal material added to the short arm (0.10 to 0.14% of the autosomal DNA). About 0.50% of the autosomal DNA was deleted from the long arm in two of the patients; only 0.35% of the autosomal DNA was deleted from the long arm in the third case. Within the limit of resolution, there is no evidence that the material lost has been translocated intact to another chromosome. The origin of the 20q- chromosome as the result of an incomplete pericentric inversion is suggested.

Aged↗
PubMed1978

Induction of long-lived chromosome damage, as manifested by sister-chromatid exchange, in lymphocytes of animals exposed to mitomycin-C.

The cytogenetic effects of repeated vs. acute exposure to a chemical mutagen--carcinogen were determined with an in vivo system in which chemicals injected into rabbits induce sister-chromatid exchanges (SCEs). SCE induction can be monitored when the animal's peripheral lymphocytes are cultured in the presence of bromodeoxyuridine (BrdUrd) and then scored for SCE frequency. Mitomycin-C (MMC), 0.5 mg/kg, was injected intraperitoneally once a week for 8 weeks. This treatment initially induced small increases in SCE frequency within one day of injection, followed by a return to control levels within 1 week. After the 4th injection, however, the frequency failed to return to normal. After the 5th injection, however it showed a 4-fold increase over the control which was sustained for the remaining 3 weeks of treatment and for an additional 2 weeks thereafter. The frequency then dropped to twice the control value and remained at this level for more than 4 months. All of the high SCE values after the first 4 weeks were due in part to the appearance and persistence of a population of cells with high SCE frequencies. Exposure to the same total dose given as a single injection resulted in a transient elevation in the SCE frequency and a subsequent return to lower values, with no evidence of a delayed effect such as the increase observed after 4 weeks in repeatedly exposed animals. Overall, repeated exposure is at least as effective as acute exposure in eliciting long-lived SCEs in vivo.

Animals↗
PubMed1977

The distribution of mitomycin C-induced sister chromatid exchanges in the euchromatin and heterochromatin of the Indian muntjac.

The frequency of sister chromatid exchanges (SCEs) induced by mitomycin C (MMC) in Indian Muntjac chromosomes was determined by the fluorescence plus Giemsa (FPG) technique. Using scanning cytophotometry the relative DNA content of each chromosome was measured with and without acid or alkali pretreatments for C-banding. During acid and alkali treatments, euchromatin lost 20 to 30% of its DNA, while heterochromatin lost less than 5%; an intermediate DNA loss was observed for the short arm of the X chromosome. After growth of cells in the presence of MMC during the first cycle and in the presence of bromodeoxyuridine (BrdU) during the first and second cycles of DNA replication, SCEs in the euchromatin were proportional to DNA content. SCEs at the junctions between the neck of the X chromosome and the long and short arms occurred more frequently than expected. A threshold effect for the induction of SCEs was observed in regions resistant to DNA extraction by acid and alkali treatments (i.e., the neck and short arm of the X chromosome). At high concentrations of MMC, the frequency of SCE at each junction appears to plateau at 0.5.

Animals↗
PubMed1977

The interaction of Hoechst 33258 and BrdU substituted DNA in the formation of sister chromatid exchanges.

Sister chromatid exchanges (SCEs) are induced in cultured Chinese hamster cells by treatment with 5-bromodeoxyuridine (BrdU) or with Hoechst 33258 (H33258) plus BrdU. The SCE frequencies depend upon the number of H33258 molecules available per cell (or per base pair) and the number of brdU molecules available per cell, and not solely upon molarity. In addition, H33258 and BrdU act synergistically to induce SCEs. At low BrdU concentrations H 33258 induces very few SCEs. At high BrdU concentrations and similar concentrations of H33258, however, SCE frequencies are significantly increased. SCE frequencies decrease with time in successively harvested cells because of the depletion of H33258 from the medium due to DNA binding.

Benzimidazoles↗
PubMed1977

The DNA content of micronuclei induced in mouse bone marrow by gamma-irradiation: evidence that micronuclei arise from acentric chromosomal fragments.

The DNA contents of 75 micronuclei found in mouse bone marrow 48 h after a 260 R dose of gamma-rays were measured individually and compared to 71 diploid G1 nuclei. The coefficient of variation for the diploid cells was 6.3%. The DNA content of micronuclei varied from 0.5 to 11.1% of the diploid G1 nuclei with a mean of 3.5%. These results are in agreement with the expectations based upon the hypothesis that micronuclei arise from acentric chromosomal fragments produced by random breakage of the mouse genome.

Animals↗