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B Carritt

Publications and source records attributed to B Carritt.

At least 55 records · Page 3Linked to original sources
PubMed1987

Genome analysis of small cell lung cancer (SCLC) and clinical significance.

A chromosome analysis of three cell lines derived from SCLC showed deletions of the short arm of chromosome 3 with bands p21-p23 as the shortest region of overlap. Hybridization of a polymorphic 3p21 probe to DNA from leukocytes of seven SCLC patients revealed heterozygosity for two of them. In the tumours of both these patients the probe detected homozygosity. This suggests the presence of a mutant cancer gene in the short arm of chromosome 3 which might express itself and/or activate some oncogene(s) after deletion of a suppressing normal allele. Amplification of the oncogene C-MYC was found in four cell lines including the ones cytogenetically analyzed. Amplification of C-MYC, though to a lesser degree, was also found in an available pleural effusate from which one of these lines had been established. As shown by in situ hybridization, the amplified oncogene was present in double minutes in three of the cell lines. In the remaining line it was in a homogeneously staining chromosome region. All patients from whom cell lines with C-MYC amplification were obtained had a negative response to chemotherapy. The observed correlation between amplification of C-MYC, occurrence of so-called variant type SCLC-derived cell lines, and negative response to chemotherapy indicates that a genome analysis of SCLC might provide further criteria for the characterization and subdivision of this highly malignant cancer and thereby a base for an optimal selection of therapy for distinct cases of SCLC.

Carcinoma, Small Cell↗
PubMed1986

Restriction fragment length polymorphisms in the D7S1 region of human chromosome 7.

A restriction fragment length polymorphism in the D7S1 region of chromosome 7 is detected by hybridizing the recombinant plasmid pA2H3 to HindIII- or HinfI-digested human DNA. Three HindIII and two HinfI alleles were detected, and it was found that all individuals carrying the variant HinfI allele also had the commoner of the two variant HindIII alleles. All variants seem to result from point mutation in restriction enzyme recognition sites. Restriction mapping of the D7S1 region revealed that the associated HindIII and HinfI alleles are defined by sites 300 base-pairs (bp) apart, and it is suggested that the close proximity of these sites is sufficient to account for the strong phenotype association observed.

Alleles↗
PubMed1986

Assignment of the human gene for beta-glycerol phosphatase to chromosome 8.

The segregation of the human gene for beta-glycerol phosphatase (GPB) was examined in human-Syrian hamster and human-Chinese hamster somatic cell hybrids. Electrophoretic analysis of the GPB in hybrids suggested that the enzyme is a dimer. Human GPB cosegregated with chromosome 8 in the twenty-five hybrids examined.

Animals↗
PubMed1986

Sequences homologous to the human D1S1 locus present on human chromosome 3.

We have investigated the segregation, in somatic cell hybrids, of the human D1S1 locus, previously assigned to 1p36 by in situ hybridization. We have shown that the clone which defines this locus, lambda Ch4A-H3, originates from human chromosome 3, but contains a 1.7-kilobase (kb) PstI-HindIII repetitive element that is also present on chromosome 1, probably distal to PGD. The clone recognizes restriction fragment length polymorphisms within the single-copy sequence on chromosome 3 and one for the enzyme StuI in the repeated sequence on chromosome 1. These experiments thus expose a level of complexity in the D1S1 locus not revealed by earlier in situ hybridization studies.

Animals↗
PubMed1984

The identification of a DNA polymorphism of the alpha fibrinogen gene, and the regional assignment of the human fibrinogen genes to 4q26-qter.

We have identified a common restriction fragment length polymorphism of the alpha fibrinogen gene with the enzyme TaqI. This polymorphism is probably due to a single base change that creates or destroys a TaqI recognition site about 1000 basepairs from the 3' end of the alpha fibrinogen géne. The frequency of the rare allele in 83 unrelated healthy individuals is 0.33. We have used in situ hybridisation of the alpha fibrinogen cDNA to localise the gene on chromosome 4q29-31. We have confirmed this regional localisation by restriction fragment detection in a human X Chinese hamster somatic cell hybrid which contains a translocated human chromosome 4 with a breakpoint at 4q26. The alpha, beta, and gamma fibrinogen genes are all present on human chromosome 4q26-qter.

Base Sequence↗
PubMed1983

Isolation of a polymorphic DNA segment unique to human chromosome 7 by molecular cloning of hybrid cell DNA.

DNA isolated from a rodent-human hybrid cell line containing human chromosomes 3, 7, 9, 10, 14 and 22 was cloned in the plasmid vector pAT153. Recombinant plasmids containing inserts of human origin were identified by colony hybridization to 32P-labelled human DNA under conditions in which only repetitive sequences interact. Single- and low-copy sequences were liberated from these plasmids by restriction endonuclease digestion and used as hybridization probes against human DNA and DNA isolated from a panel of Chinese hamster-human hybrids. One single-copy probe was shown to react with a genomic sequence unique to human chromosome 7 and to recognize an apparent restriction fragment size polymorphism in human DNA.

Animals↗
PubMed1983

A genetic characterization of the human diaphorase-4 deficiency.

Analyses of DIA4 activity in cultured cells from a random population, a small family and human/rodent somatic cell hybrids support the view that the quantitative polymorphism of human DIA4 can be attributed to the segregation of a 'low activity' allele. (1) In a series of lymphoblastoid cell lines from 52 unrelated individuals, three lines were found which did not exhibit DIA4 after electrophoresis and showed low levels of NADPH diaphorase activity. The frequency (6%) of the DIA4 'absent' phenotype is close to that (4%) determined previously by analysis of post-mortem tissue. (2) Cultured fibroblasts from a small family in which the DIA 4 low-activity allele was apparently segregating were analysed. The NADPH diaphorase activity of the propositus (DIA4 'absent' phenotype) was very low (less than 6% of normal). He also exhibited very weak DIA4 isozymes of unusual electrophoretic mobility. The activity of both parents and sib was about half the normal level, suggesting that these individuals are heterozygous for the low-activity allele. (3) Analysis of a series of independent human/hamster hybrid clones, made using a human parent heterozygous for phosphoglycolate phosphatase (PGP) and DIA4, suggested that in this particular individual the DIA 4 low-activity allele segregates with the PGP 2 allele. However, there were 2 hybrids amongst a total of 16 which gave discordant results and these are to be the subject of further analysis by subcloning.

Alleles↗
PubMed1982

Diverse origins of multiple ovarian teratomas in a single individual.

Centromere heteromorphisms and enzyme markers were examined in cells cultured from seven benign ovarian teratomas arising in a single patient. Three of the teratomas were homozygous for all eight enzyme and centromere markers found to be heterozygous in the host. The other four tumors were heterozygous at the centromeres of chromosomes 1, 16, 17, and 18, as in the patient, but were homozygous for at least one of the enzyme markers. The linkage phases of the heterozygous enzyme markers phosphogluconate dehydrogenase and phosphoglucomutase 1 and the chromosome 1 centromere heteromorphism were established for the patient and for three of the heterozygous teratomas by analysis of Chinese hamster-human somatic cell hybrids. The linkage phase of these markers in homozygous and heterozygous tumors was in every case different from that in the host. The finding of heterozygous centromeres in ovarian teratomas excludes suppression of meiosis II as a mechanism for their origin, and we suggest rather that they arise by failure of meiosis I. The linkage phases in the fully homozygous tumors are most readily derived from that in the patient, we suggest, by endoreduplication of a haploid gamete. The varied origin of ovarian teratomas has important implications for the suitability of such material for centromere-based gene mapping.

Adult↗
PubMed1980

Assignment of the human locus determining phosphoglycolate phosphatase (PGP) to chromosome 16.

The segregation of human phosphoglycolate phosphatase has been studied in 52 independent human-rodent hybrids and 69 subclones. The results suggest that human PGP is on chromosome 16. Family data suggest that PGP is not close to 16qh or alpha Hp. The most likely regional assignment for PGP would appear to be 16p13 or 16p12, but a site on 16q cannot be entirely excluded. New data on 16qh and alpha Hp suggest that the male recombination fraction between these loci is about 0.2.

Alleles↗
PubMed1979

Regional asssignments of the loci AK3, ACONS, and ASS on human chromosome 9.

Experiments are described in which human cells carrying balanced reciprocal translocations involving four different regions of chromosome 9 were fused with a Chinese hamster cell line and the resulting hybrids used to obtain subchromosomal assignments of the loci ASS, AK3, and ACONS. ASS was localized on the distal portion of the long arm of chromosome 9, in the region 9q34 leads to 9qter, and AK3 and ACONS on the short arm, in the region 9pter leads to 9p13.

Aconitate Hydratase↗
PubMed1977

Variant Chinese hamster cells resistant to the proline analog L-azetidine 2-carboxylic acid.

Variants resistant to the toxic effects of the proline analog L-azetidine 2-carboxylic acid (AZCA) have been isolated from the Chinese hamster tissue culture line G3 by a three-step selection procedure using increasing concentrations of AZCA. Cells surviving each of the three selective steps have been examined for AZCA resistance and for proline uptake, biosynthesis, and degradation. The largest increment in AZCA resistance is acquired in the third step and is due to overproduction of proline as a result of increased activity of the enzyme system responsible for the conversion of glutamic acid to glutamic gamma-semialdehyde. It is not accompanied by an increase in the rate of formation of proline from ornithine or in the rate of proline uptake or degradation.

Azetidinecarboxylic Acid↗