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Biomedical subjects

C Jones

Publications and source records attributed to C Jones.

At least 595 records · Page 33Linked to original sources
PubMed1986

Localization of the gene encoding 3-hydroxy-3-methylglutaryl-coenzyme A synthase to human chromosome 5.

A series of hybrids between primary human cells and a Chinese hamster somatic cell mutant (Mev-1), defective in expression of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) synthase [(S)-3-hydroxy-3-methylglutaryl-CoA acetoacetyl-CoA-lyase (CoA-acetylating, EC 4.1.3.5], has been prepared that complements the mutant defect. A technique based on differential sensitivity of this enzyme activity to inhibition by magnesium ion is described that allows the discrimination of expression of human and hamster HMG-CoA synthase in these hybrids. The results indicate a structural gene defect in expression of HMG-CoA synthase activity in Mev-1 cells. Segregation of human chromosomes that do not possess the complementing marker have allowed the assignment of human HMG-CoA synthase activity to chromosome 5. This is the second demonstrably transcriptionally regulated enzyme of cholesterologenesis to be assigned to chromosome 5, the other being HMG-CoA reductase.

Chromosome Mapping↗
PubMed1986

Production of Chinese hamster monoclonal antibody to a human cell-surface antigen using a hamster-human somatic cell hybrid as antigen.

Hybridomas producing monoclonal antibody (MAb) of predefined specificity were isolated from a Chinese hamster that had received injections of a Chinese hamster-human somatic cell hybrid. A standard method for the production of murine hybridomas was used to produce Chinese spleen lymphocyte X murine plasmacytoma hybridomas, and they were screened for complement-mediated cytotoxicity against a panel of Chinese hamster-human somatic cell hybrids and agglutination of human erythrocytes. Two hybridomas were established in tissue culture following limiting dilution cloning, and their reactivity with a panel of Chinese hamster-human somatic cell hybrids indicates that they are specific for the previously identified human cell-surface antigen a1. The Chinese hamster appears to respond preferentially to human antigens of Chinese hamster-human somatic cell hybrids, and it will serve as a useful tool for the production of MAb specific for human cell-surface antigens expressed in the many well-characterized Chinese hamster-human somatic cell hybrids available.

Animals↗
PubMed1986

The human type II collagen gene (COL2A1) assigned to 12q14.3.

A cosmid clone containing the entire human type II alpha 1 collagen gene (COL2A1) was used as probe in the Southern analysis of DNA from a panel of human/hamster somatic cell hybrids containing different portions of human chromosome 12. Two of the hybrids exhibited a similar terminal deletion q14.3----qter, but one was positive for the gene while the other was negative. Therefore, the gene must reside in the region q14.3.

Animals↗
PubMed1986

Comparison of the MicroScan system with the API Staph-Ident system for species identification of coagulase-negative staphylococci.

To evaluate the accuracy of the MicroScan System (American Hospital Supply Corp., Sacramento, Calif.) for identification of coagulase-negative staphylococci, we tested 175 clinical isolates of coagulase-negative staphylococci. The results obtained by the MicroScan system were compared with those of the API Staph-Ident system (Analytab Products, Plainview, N.Y.). Forty-three discrepancies between the two systems were resolved by the conventional method of Kloos and Schleifer (W.E. Kloos and K.H. Schleifer, J. Clin. Microbiol. 1:82-88, 1975). The MicroScan and the Staph-Ident systems correctly identified 146 (86.4%) and 154 (88%) of 175 strains, respectively. The API system failed to identify phosphatase-negative Staphylococcus epidermidis. The MicroScan system demonstrated the greatest accuracy in the identification of S. epidermidis and S. saprophyticus, whereas lesser accuracy was achieved with S. hominis, S. warneri, and S. sciuri.

Bacteriological Techniques↗
PubMed1986

Inability of the Chemstrip LN compared with quantitative urine culture to predict significant bacteriuria.

The Chemstrip LN (Boehringer Mannheim Biochemicals, Indianapolis, Ind.), designed to detect pyuria and bacteriuria, was compared with culture of 1,020 unselected, consecutive midstream urine specimens and evaluated on its ability to predict colony counts at three levels. At the level of greater than or equal to 10(5) CFU/ml, the combined test (detection of leukocyte esterase and nitrite) had sensitivity of 82.3%, specificity of 67.9%, positive predictive value of 41.3%, and negative predictive value of 93.3% at prevalence rate of 21.6%. The test would have rejected 9.4% of the specimens with significant bacteriuria if the Chemstrip alone had been used.

Bacteria↗
PubMed1986

Treatment of uncomplicated gonorrhoea with single dose aztreonam.

Infection with Neisseria gonorrhoeae was cleared in 61 men and 26 women at all sites (except in the pharynx of one male bisexual patient with urethral and pharyngeal gonorrhoea) after treatment with aztreonam as a single 1 g intramuscular injection. Aztreonam was well tolerated with no adverse effects. This monobactam antibiotic was effective against both penicillin sensitive and resistant strains.

Adult↗
PubMed1986

Anti-ulcer drugs and intrinsic factor secretion.

Twelve healthy volunteers were randomly allocated to take two of the following treatments; cimetidine, misoprostol (a prostaglandin E1 analogue) and carbenoxolone, for two weeks. A further four subjects took ranitidine. Gastric aspirates were collected before and on the 14th day of therapy for each drug, and analysed for intrinsic factor concentration and total output. Both randitine and cimetidine inhibited pentagastrin stimulated output by 47% and 27% respectively in comparison to control, but had no effect on stimulated mean intrinsic factor concentrations. No changes were observed with misoprostol and carbenoxolone treatment.

Adult↗
PubMed1986

The p97 antigen is mapped to the q24-qter region of chromosome 3; the same region as the transferrin receptor.

Since the p97 antigen, a membrane-associated iron-binding protein, has extensive amino acid sequence with homology with transferrin, is functionally related to the transferrin receptor, and has been previously mapped to chromosome 3, we have performed additional studies for regional mapping of the gene expressing p97 antigen. In these experiments, Chinese hamster-human cell lines were chosen that contained a large spectrum of autosomal human chromosomes, but mainly consisted of clones expressing all or a part of chromosome 3. These cell lines included a clone that previously allowed for mapping of human transferrin receptor to q22-qter region. Human p97 expression was assessed by specific binding of [125I]monoclonal antibody 96.5, and human transferrin receptor expression was tested by specific [125I]human transferrin binding and [125I]monoclonal antibody OKT-9 specific for human transferrin receptor. Based on these analyses, both human p97 antigenic expression and human transferrin receptor are mapped concordantly to the q24-qter region. These data and previous reports, therefore, suggest that the related iron-transport proteins are closely linked and may be under coordinate regulation. However, studies of several cell lines that exhibit up-regulation of human transferrin receptor expression with cellular proliferation, and down-regulation of receptor with increased transferrin-iron in the media, showed no change in expression of p97 antigen. p97 antigenic expression increased when melanocyte-stimulating hormone was added to a human melanoma cell line in tissue culture. These latter studies suggest that in mammalian cells the two proteins do not show coordinate regulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Martial arts for the quadriplegic.

A program has been developed for teaching of martial arts to the spinal cord injured. Despite the great challenges, quadriplegic patients have been able not only to participate along with paraplegics, but have helped to develop innovative methods to modify techniques to their abilities. The benefits of the program are described.

Exercise Therapy↗
PubMed1985

Blood content of broiler chicken carcases prepared by different slaughter methods.

Two trials using broiler chickens were undertaken to determine if variations in commercial slaughter techniques affected either the appearance or the residual blood content of the carcases produced. In the first trial groups of broilers were either stunned (55, 80 or 105 volts), electrocuted (240 volts) or anaesthetised and the subsequent bleed-out volumes after one, two, three and four minutes exsanguination were measured. The method of slaughter made no difference to the amount of blood lost after venesection. Haemoglobin content of the pectoral muscle was used to measure residual blood and was uniformly low in all groups (0.7 to 0.16 mg haemoglobin/g of muscle). In the second trial groups of chickens were either stunned and bled out, electrocuted, electrocuted and bled out, decapitated or halal killed before processing. The edible portions of the carcases were minced and the average haemoglobin content for each group was 0.19, 0.36, 0.22, 0.17 and 0.17 mg/g of soft tissue. The appearance of chickens that were stunned and bled out was the same as that of chickens that were electrocuted and bled out. The authors conclude that killing chickens by electrocution before exsanguination does not adversely affect the carcase appearance. Furthermore, electrocution ensures that broiler chickens are humanely slaughtered.

Abattoirs↗
PubMed1985

Identification of the tetrasaccharide repeating-unit of the Streptococcus pneumoniae type 23 polysaccharide by high-field proton n.m.r. spectroscopy.

One- and two-dimensional 500-MHz 1H-n.m.r. studies of the capsular polysaccharide from Streptococcus pneumoniae type 23 have been used to determine its structure, which was confirmed by limited degradation. The proposed structure (1) differs from those suggested previously and the phosphate group has been located tentatively at position 3 of the glucosyl residue. (Formula: see text).

Carbohydrate Conformation↗
PubMed1985

Human T-cell receptor alpha-chain genes: location on chromosome 14.

The genes encoding the alpha chain of the human T-cell receptor have been mapped to chromosome 14, the chromosome on which the human immunoglobulin heavy chain locus resides. Thus, genes encoding two different classes of antigen receptor are present on the same chromosome. Furthermore, breaks involving chromosome 14 are frequently seen in tumors of T-cell origin. The potential relation of these chromosome abnormalities to alpha-chain genes is discussed.

Animals↗
PubMed1985

The gene coding for a sphingolipid activator protein, SAP-1, is on human chromosome 10.

SAP-1 is a sphingolipid activator protein found in human tissues required for the enzymatic hydrolysis of GM1 ganglioside and sulfatide. It appears to be missing in patients who have a genetic lipidosis resembling juvenile metachromatic leukodystrophy. Using rabbit antibodies against human SAP-1 it could be visualized in extracts from cultured human skin fibroblasts after sodium dodecylsulfate-polyacrylamide gel electrophoresis, followed by electroblotting to nitrocellulose membrane and immunochemical staining (Western blotting). A series of 23 human-Chinese hamster ovary cell hybrids containing different human chromosomes were examined. The parent Chinese hamster ovary cells did not have a reacting protein in the region of human SAP-1. Only in the eight hybrid clones containing human chromosome 10 was a reacting protein identified. Other chromosomes were excluded by this method. Therefore the gene for SAP-1 and the genetic mutation resulting in a fatal lipidosis are located on human chromosome 10.

Animals↗
PubMed1985

Association of phosphorylated simian virus 40 T-antigen with subnuclear fractions of infected and transformed cells.

To define the roles of subnuclear structure in SV40 infection, the relative distribution of T-antigen (T-ag) in various subnuclear fractions obtained from both lytically infected and transformed African green monkey kidney cells was determined. Depending on the differential sensitivity of nuclear T-ag to extraction by salt and detergent, nuclear T-ag could be separated into nucleoplasmic T-ag, salt-sensitive T-ag and matrix-bound T-ag subclasses. At least fivefold less matrix-bound T-ag was found in transformed cells than in lytically infected cells. While a cAMP-independent protein kinase was detected in the nuclear matrix, the matrix-bound T-ag (94K) could not be phosphorylated in vitro. The removal of cellular chromosomes by DNase caused changes in the interaction of T-ag with nuclear components. The results suggest that the compartmentalization of nuclear T-ag may be determined by its interaction with host chromosomes.

Animals↗
PubMed1985

Specific-locus mutation response to unequal, 1 + 9 Gy X-ray fractionations at 24-h and 4-day fraction intervals.

The specific-locus mutation frequency obtained from mouse spermatogonial stem cells following unequal, 1 + 9 Gy X-ray fractionation with a 24-h fractionation interval is low, and consistent with the two fractions acting additively. The response is therefore markedly different from the augmented mutation frequencies obtained with 500 + 500 R and 100 + 500 R, 24-h fractionations. The lower yield compared with the 100 + 500 R response also indicates a clear difference from the translocation data which demonstrate increases in yield with increasing second dose over the same dose range. The decline in specific locus mutation yield with the increase in the second dose from 500 R to 9 Gy suggests that the stem cells surviving the first fraction are heterogeneous in their sensitivities to this class of genetic damage. A similar, additive specific locus mutation frequency is obtained with unequal, 1 + 9 Gy X-irradiation when the interval between fractions is 4 days. This is consistent with 500 + 500 R, 4-day and 7-day interval responses obtained previously but again differs from the sub-additive translocation responses obtained with such X-ray fractionation. Taken together with the data from previous studies the present results suggest that (1) 24 h after the first fraction, (a) the surviving stem cell have two components; survivors of the formerly radiosensitive, cycling component of the normal stem cell population and the formerly radioresistant, G0 or arrested G1 cells, which are being 'triggered' into a rapid cell cycle to achieve repopulation of the testis; (b) these two components are of near-equal sensitivity to translocation induction and cell killing, hence the additive translocation yields with equal X-ray fractionations and yields consistent with those extrapolated from lower doses with higher, unequal fractionations, e.g. 1 + 7 Gy, 1 + 9 Gy; but (c) the formerly radioresistant, triggered component is much more sensitive than the surviving cycling component to specific locus mutation and cell killing, hence the augmented mutation response with 500 + 500 R fractionation and the drop in yield with 1 + 9 Gy compared with 100 + 500 R X-irradiation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Role of the SulB (FtsZ) protein in division inhibition during the SOS response in Escherichia coli: FtsZ stabilizes the inhibitor SulA in maxicells.

Induction of the SOS response in Escherichia coli by DNA-damaging treatments results in the synthesis of the SulA polypeptide, and this is sufficient to cause the resulting inhibition of cell division. Mutations at either sulA (sfiA) or sulB (sfiB) suppress this division inhibition. The SulB protein is identical to FtsZ, a protein required for normal division in E. coli. In the presence of FtsZ, the half-life of SulA synthesized in maxicells is approximately 12 min. In contrast, in the absence of FtsZ or in the presence of a mutant form of FtsZ (SulB114) that prevents division inhibition in vivo, SulA is extremely unstable with a half-life of only 3 min. Both FtsZ and SulA are isolated with the inner membrane of E. coli maxicells in the presence of MgCl2. We propose that the SulA inhibitor interacts directly with FtsZ in vivo to block the essential division function of this protein.

Bacterial Proteins↗