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Biomedical subjects

C Jones

Publications and source records attributed to C Jones.

At least 559 records · Page 31Linked to original sources
PubMed1988

Mapping studies and expression of genes located on human chromosome 11, band q23.

Chromosome translocations and deletions may alter cellular proto-oncogenes and result in cellular changes that are important in the pathogenesis of malignancy. The region 11q23 is frequently involved in human malignancy. Utilizing a leukemic cell line with a reciprocal translocation involving 11q23 and somatic cell hybrids derived from this cell line, we analyzed five genes assigned to 11q23: NCAM, CD3D, CD3E, THY1, and ETS1. Our data showed no evidence of direct involvement of these genes in this leukemia but enabled a partial genetic map of this important region of the human genome to be constructed: 11cen--NCAM--CD3([G, D], E)--parallel--(ETS1, THY1)--11qter.

Animals↗
PubMed1988

The gene encoding the hydrophobic surfactant protein SP-C is located on 8p and identifies an EcoRI RFLP.

Pulmonary surfactant is composed primarily of phospholipids but also contains three known surfactant-specific proteins. These proteins are important in determining the physical properties of pulmonary surfactant--including its ability to adsorb to an air-liquid interface and its structure--but also appear to influence surfactant metabolism. We have previously assigned two surfactant proteins, SP-A (a 28-36-kDa glycoprotein) and SP-B (an 18-kDa hydrophobic protein), to the short arm of chromosome 10 and to chromosome 2, respectively. We now report that the gene encoding the 5-8 kDa hydrophobic surfactant protein SP-C is located on the short arm of chromosome 8. A cDNA clone encoding the entire protein recognizes a useful EcoRI restriction-site-length polymorphism. Evaluation of congenital syndromes manifesting autosomal abnormalities does not further elucidate the functional role of this protein in promoting normal respiratory physiology.

Animals↗
PubMed1988

Quantitation of human serum polymeric IgA, IgA1 and IgA2 immunoglobulin by enzyme immunoassay.

This report concerns the relative quantitation of serum polymeric IgA and polymeric IgA subclass concentrations by enzyme immunoassay (EIA). The assay relies on the specific binding of polymeric IgA to secretory component. Competition between pentameric IgM and polymeric IgA for binding to secretory component was observed. Thus, samples were adsorbed for IgM by affinity chromatography before the EIA was performed. The assay was used to determine an age-related range of serum polymeric IgA concentrations and to compare the polymeric IgA concentrations in patients with IgA nephropathy (n = 50) to those of controls (n = 50). The serum concentrations of both polymeric IgA and polymeric IgA1 increased with age reaching adult values of around 12 years of age. Polymeric IgA2 concentrations did not reach adult levels until 18 years of age. The ratio of the polymeric IgA concentration to the total serum IgA concentration was found to be significantly increased in children under 2 years of age compared with those over 4 years of age (Mann-Whitney U-test, P less than 0.01). Patients with IgA nephropathy had significantly increased concentrations of polymeric IgA (P = 0.001) and polymeric IgA1 (P = 0.001) but similar polymeric IgA2 concentrations to controls.

Adolescent↗
PubMed1988

2-[(Aminopropyl)amino] ethanethiol-mediated reductions in 60Co gamma-ray and fission-spectrum neutron-induced chromosome damage in V79 cells.

The radioprotector 2-[aminopropyl)amino] ethanethiol (WR1065), which has been reported to reduce the cytotoxic and mutagenic effects of low LET radiation, was investigated for its ability to protect against low LET (60Co gamma ray) and high LET (fission-spectrum neutron)-induced chromosome damage in V79 cells. Cells were irradiated in G2 phase in the presence or absence of 4 mM WR1065 and were harvested and analyzed 2 h later for chromatid-type aberrations. Irradiation of G2-phase V79 cells in the presence of WR1065 resulted in a 30 to 50% reduction in the frequency of gamma-ray and neutron-induced chromatid-type breaks and exchanges. The effects were found only after exposures of greater than 200 cGy gamma-ray or 50 cGy neutron irradiation. The radioprotector was effective at reducing neutron-induced aberrations after exposures at dose rates of both 10 and 43 cGy/min. Thus the radioprotector WR1065 is an effective anti-clastogenic agent in V79 cells, protecting against both 60Co gamma-ray and fission-spectrum neutron-induced aberrations, when present during irradiation.

Animals↗
PubMed1988

Subperiosteal hemangioma. A case report and review of the literature.

Subperiosteal hemangioma (SPH), an exceptionally rare lesion, was diagnosed in a 68-year-old man. SPH is usually small and is most commonly located in the midshaft of a long tubular bone such as the tibia or fibula. A wide range of age groups is affected. SPH may present with mild pain or local swelling unassociated with trauma. Radiologically, it usually appears as a shallow cup-shaped depression surrounded by cortical thickening. Several other periosteal and intracortical lesions must be considered in the differential diagnosis, but the final diagnosis rests on microscopic evaluation. The treatment of SPH is marginal excision; local recurrences have not been reported after such treatment.

Aged↗
PubMed1987

Association of viral and plasmid DNA with the nuclear matrix during productive infection.

The association of simian virus 40 (SV40) DNA or plasmid DNA in subcellular fractions from either infected or transfected cells was examined. In lytically infected cells, approx. 25% of viral specific DNA during the infection cycle was retained in nuclei after washing with low ionic strength buffer and 1% Triton X-100. Viral replicating DNA found in the nuclear matrix was capable of performing limited DNA synthesis by the endogenous DNA polymerase in vitro. Viral DNA synthesized in vitro hybridized preferentially to SV40 Hind-III B and C fragments which are in proximity to the origin of replication. In plasmid-transfected COS-7 cells (SV40-transformed cells), the amount of plasmid DNA found in the nuclear matrix was related to its replication efficiency in cells. More than 80% of the plasmid DNA was tightly associated with subnuclear structures. Little or no plasmid DNA was found in the cytoplasmic fraction. The results suggest that, in extrachromosomal model systems, the association of DNA with nuclear matrix is important for the regulation of DNA replication.

Animals↗
PubMed1987

Different subfamilies of alphoid repetitive DNA are present on the human and chimpanzee homologous chromosomes 21 and 22.

The alphoid repeat DNA on chimpanzee chromosome 22 was compared with alphoid repeat DNA on its human homologue, chromosome 21. Hybridization of different alphoid probes under various conditions of stringency show that the alphoid repeats of chimpanzee chromosome 22 are not closely related to those of human chromosome 21. Sequence analysis of cloned dimer and tetramer EcoRI fragments from chimpanzee chromosome 22 confirm the low overall level of homology, but reveal the presence of several nucleotide changes which are exclusive to the chromosome 21 subfamily of human alphoid DNA. Southern blot analysis of alphoid repeat DNA on the chimpanzee X chromosome suggests this subfamily has been strongly conserved during and since the separation of chimpanzee and man although the two subfamilies can be distinguished on the basis of Taq I restriction fragments.

Animals↗
PubMed1987

Regional localization of the gene coding for sphingolipid activator protein SAP-1 on human chromosome 10.

Sphingolipid activator protein SAP-1 is required for the enzymatic hydrolysis of GMI ganglioside and sulfatide. The gene coding for SAP-1 was previously mapped to human chromosome 10 using monospecific antibodies prepared against SAP-1 in synteny analysis of somatic cell hybrids. In this study, we used a cDNA probe for SAP-1 and in situ hybridization to regionally localize the SAP1 gene to the long arm of chromosome 10, region q21-22. Additional mapping data using cell hybrids containing partial chromosome 10 and skin fibroblasts with trisomy 10p are consistent with the in situ hybridization mapping results.

Chromosome Banding↗
PubMed1987

Molecular cloning of MER-2, a human chromosome-11-encoded red blood cell antigen, using linkage of cotransfected markers.

We report the molecular cloning of a human gene MER-2 located on chromosome 11 that encodes a cell surface antigen which is polymorphic on red blood cells. An essential element of the cloning strategy was cotransfection-induced linkage of pSV2-neo, which encodes resistance to the antibiotic G418, to the human MER-2 gene. An important feature of the pSV2-neo construct is that the same gene (the transposon, Tn5) that encodes G418 resistance in eukaryotic cells confers neomycin resistance in bacteria. Chinese hamster ovary (CHO) cells were cotransfected with pSV2-neo and genomic DNA from a CHO X human cell hybrid containing a single human chromosome (chromosome 11). Transfectants expressing both the human MER-2 gene and G418 resistance were isolated by selection in the antibiotic G418, followed by indirect immunofluorescence using the monoclonal antibody 1D12, which recognizes the MER-2 antigen, manual enrichment, and single-cell cloning. Genomic DNA from a primary transfectant positive for MER-2 expression and G418 resistance was used to construct a cosmid library and cosmid clones able to grow in neomycin were isolated. Of 150,000 cosmid clones screened, 90 were resistant to neomycin and of these, 11 contained human repetitive sequences. Five neomycin-resistant cosmid clones containing human repetitive DNA were able to transfect CHO cells for G418 resistance and MER-2 expression.

Animals↗
PubMed1987

Analysis of human chromosome 11 by somatic cell genetics: reexamination of derivatives of human-hamster cell line J1.

Through the fusion of a CHO cell population to a human cell population, a hybrid cell line which has lost all human chromosomes except chromosome 11 was derived. This cell line, J1, does not appear to segregate human chromosome 11 during growth. A series of deletion segregants were isolated from J1 which had lost a portion of either the long, short, or both arms of chromosome 11. This panel of deletion segregants was used for mapping a number of genetic markers on the short arm of chromosome 11. Karyotypic analysis led to the interpretation that derivatives of J1 selected for the loss of cell surface antigens encoded by genes on the short arm of the chromosome had simple terminal deletions of this chromosome arm. More recently, we have applied recombinant DNA and in situ hybridization techniques to the analysis of the structure of chromosome 11. In the course of this analysis, we have obtained data that indicate that all J1 deletion segregants retain a small chromosomal segment containing the structural genes for insulin and HRAS1. Analysis of in situ hybridization data indicates that in cell lines in which a chromosome 11 fragment cannot be identified by karyotype analysis, human DNA has been translocated to a Chinese Hamster chromosome. These results suggest that the original interpretation of the karyotypes of deletion segregants derived from J1 as simple terminal deletions is not correct. A reanalysis of gene localization studies based on these deletion segregants suggests that some assignments of genes to specific bands on chromosome 11 should be reconsidered. In particular, data on additional deletion segregants are consistent with localization of the beta-globin gene complex to band 11p15. The data presented here suggest that in several hybrid derivatives of J1, a continuous DNA segment of approximately 10(7) base pairs in length which includes the insulin and HRAS1 (cellular homolog of retroviral oncogene Harvey ras) genes has been isolated from the remainder of the human genome. We propose that the stability of chromosome 11 in the original hybrid was due to complementation of a genetic defect in the original CHO cell parent by a gene located in close physical proximity to the insulin and HRAS1 genes on chromosome 11. Data are presented which test and support this hypothesis.

Animals↗
PubMed1987

Three distinct epitopes of the human MSK20 cell surface antigen are expressed on human and nonhuman primate cells.

Five monoclonal antibodies which indirectly agglutinate human rbc were isolated and designated 2D8, 4E12, 4H10, 5A8, and 5H5. Expression of the antigen defined by 2D8 was 100% concordant with the presence of human chromosome 19 in a panel of human-Chinese hamster somatic cell hybrids. Secondary clones isolated from antigen positive hybrids exposed to antibody 2D8 and complement were shown to have lost both the cell surface antigen and chromosome 19. Small terminal deletions of 19p were observed in the karyotypes of two antigen negative clones that continued to express human GPI. All five monoclonal antibodies and the previously isolated F10 labelled the surface of parental cells and did not label the surface of deletion mutants, and the five monoclonal antibodies produced in this study inhibited the binding of F10 to the human rbc surface. Therefore, all must recognize the MSK20 cell surface antigen which was defined previously by antibody F10. Chimpanzee cells bind 5A8 and 5H5, orangutan cells bind 4E12, and neither bind 2D8 and 4H10. Therefore, the monoclonal antibodies produced in this study must recognize at least three distinct epitopes of the MSK20 cell surface antigen which are expressed on the human rbc.

Animals↗
PubMed1987

The disconnection in anomic aphasia between semantic and phonological lexicons.

PB, a right handed woman aged 26, has developed anomic language disturbances following right frontal and left temporal brain damage due to a road traffic accident. Her anomia shows exceptional features: it occurs in naming tasks in test conditions but not in continuous speech; it involves comprehension deficits but very few semantic errors in expression; it improves with phonemic, but not with semantic cues. These features, it is argued, indicate the disconnection between two intact lexicons: the semantic and the phonological.

Adult↗
PubMed1987

Human chromosomes 6 and 21 are required for sensitivity to human interferon gamma.

The human interferon gamma receptor has previously been assigned to chromosome 6. Chromosome 6 also encodes HLA, the human class I major histocompatibility antigens. However, the presence of chromosome 6 in hamster-human hybrids is by itself insufficient to confer sensitivity to human immune interferon as measured by the induction of human HLA. Human chromosome 21 was found to be the second chromosome essential for HLA inducibility. Similar results were found with mouse-human somatic cell hybrids. Thus, at least two steps are involved in the action of human interferon gamma: the binding of interferon gamma to its receptor coded by chromosome 6 and the linkage of this binding event through a factor coded by chromosome 21 to trigger biological action. Both of these steps are species-specific.

Animals↗
PubMed1987

The progesterone receptor gene maps to human chromosome band 11q13, the site of the mammary oncogene int-2.

Progesterone is involved in the development and progression of breast cancers, and progesterone receptors (PR) are important markers of hormone dependence and disease prognosis. We have used a human PR cDNA probe, genomic DNA blotting of a series of Chinese hamster-human cell hybrids, and in situ hybridization to map the human PR gene to chromosome 11, band q13. This band also contains the human homolog of the mouse mammary tumor virus integration site, int-2, which surrounds a protooncogene thought to be involved in the development of murine mammary cancers. That these two genes share the same chromosomal location raises important questions about their possible linkage and about the relationship between the mammary-specific oncogene and the steroid hormone in the development, growth, and hormone dependence of human breast cancers.

Animals↗