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Biomedical subjects

K Carlson

Publications and source records attributed to K Carlson.

At least 145 records · Page 8Linked to original sources
PubMed1980

Correlation between genetic map and map of cleavage sites for sequence-specific endonucleases SalI, KpnI, BglI, and BamHI in bacteriophage T4 cytosine-containing DNA.

Cleavage sites for SalI, KpnI, BglI, and BamHI in cytosine-containing DNA from T4 alc10(alc) nd28(denA) D2a2(denB) amE51x5(56) amN55x5(42) have been mapped relative to each other, and the positions of deletions sa delta 9 (D1-stp), r1589(rII), del(39-56)12, and tk2(rI-tk) relative to these cleavage sites have been determined. Based on these analyses, a physical map of the T4 genome containing 166 kilobase pairs has been constructed.

Chromosome Mapping↗
PubMed1980

Studies on the protein composition of human serum very low density lipoproteins with particular reference to the presence or absence of late pre-beta lipoprotein (Lp beta).

The amount of tetramethylurea and isopropanol soluble protein, total protein, triglycerides and cholesterol was determined in very low density lipoprotein (VLDL) showing either pre-beta mobility, or combined pre-beta and late pre-beta (Lp beta) or beta-mobility from twenty-two different sera. The ratios cholesterol to triglyceride of the VLDL preparations varied between 0.30 and 1.75. A very strong positive linear correlation between soluble protein and triglycerides over the whole range of VLDL preparations was obtained. There was no difference between sera with and without Lp beta for this relationship. When apolipoprotein B, was plotted against triglycerides, a weak correlation was obtained, and VLDL preparations without Lp beta separated into a group below the regression line, indicating that Lp beta is triglyceride poor in relation to apolipoprotein B. The corresponding plot against cholesterol gave a better correlation but with an even distribution of values of VLDL with and without Lp beta. Total and soluble protein put against cholesterol showed a pronounced tendency of VLDL with pure pre-beta mobility and those with Lp beta mobility to separate into groups, demonstrating that Lp beta is cholesterol rich relative to protein. The findings indicate that Lp beta-containing VLDL may represent the presence of a partly degraded VLDL.

Apolipoproteins↗
PubMed1979

Cleavage map of bacteriophage T4 cytosine-containing DNA by sequence-specific endonucleases SalI and KpnI.

Cytosine-containing T4 DNA from endoII- endoIV- dCTPase- alc2 phage grown in a sup+ rB- mB- host is cleaved by endo R.EcoRI and endo R.HindIII to greater than 40 fragments and by endo R.SalI and endo R.KpnI to 8 and 6 fragments, respectively. The latter two fragment sets have been correlated to each other to produce a cleavage map of the genome. The sum of the molecular weights of the fragments calculated from electrophoretic mobility in agarose gels yields a genome molecular weight for cytosine-containing T4 DNA of 105 x 10(6).

Cytosine↗
PubMed1979

Approaches to wage and salary determination. Implications for hospital dietitians.

Although many types of rewards are to be found in work, salaries and benefits remain primary concerns. Thus the compensation policy of the employer is of great importance to the employee. Described here are current salary administration approaches and practices, i.e., market pricing and internal equity systems. Also explained are components of wage and salary plans, including job evaluation, labor market surveys, and job pricing. A detailed discussion of methods of job evaluation--qualitative and quantitative--is presented. The paper concludes by reporting figures from a recent salary survey of four hospitals in the Chicago area.

Chicago↗
PubMed1978

Conversion of the electrophoretic pattern of type IV hyperlipidaemia to type III by intravenous heparin.

Heparin was given i.v. to subjects with type IV hyperlipoproteinaemia who had only ordinary pre-beta lipoproteins and no late pre-beta lipoproteins (LP-beta) in their very low density lipoproteins (VLDL, d less than 1.006) upon agarose gel lipoprotein electrophoresis. Within 15 min the electrophoretic pattern of VLDL had changed completely. The normal pre-beta lipoproteins had disappeared and a discrete LP-beta lipoprotein had appeared. This new electrophoretic pattern, induced 15 min after heparin, is similar to that diagnostic of type III hyperlipoproteinaemia. It is suggested that the LP-beta lipoproteins represent an end stage in the catabolism of VLDL.

Cholesterol↗
PubMed1977

Effect of storage conditions of serum lipoproteins on electrophoretic mobility in agarose gel and on lipid composition.

The effect of conditions of storage of sera and lipoprotein fractions on electrophoretic mobility in argarose gel and on lipid composition has been assessed. It was found that sera or lipoprotein fractions may be stored at 4 degrees C in the presence of ethylene diamine tetra-acetate for up to 5 days before electrophoresis or up to 8 days before estimation of cholesterol and triglycerides. Addition of mercurothiolate of p-chloromercuriphenyl sulphonate offerred no further advantage.

Blood Preservation↗
PubMed1975

Comparison of behaviour of very low density lipoproteins of type III hyperlipoproteinaemia on electrophoresis on paper and on agarose gel with a note on a late (slow) pre-beta VLDL liproprotein.

The diagnosis of type III hyperlipoproteinaemia is based on the presence of a very low density lipoprotein (VLDL) that on electrophoresis has beta instead of the usual pre-beta mobility. This definition is based on paper electrophoresis. Lipoproteins of type III sera were studied by simultaneous electrophoresis on paper and on agarose gel. On paper the ultracentrifugally isolated VLDL had beta mobility, but on agarose gel their mobility was slightly more rapid than beta. It is thus important to consider the electrophoretic conditions in the diagnosis of type III. The diagnosis of type III is further complicated by the presence of agarose gel electrophoresis - contrary to paper - of a second, a 'late pre-beta VLDL' lipoprotein (LPbeta) in 20-30 per cent of both normal and hyperlipoproteinaemic sera. Quantitative lipoprotein analysis of 609 consecutive sera showed that when LPbeta was present, both in normo- and hyperlipoproteinaemia, certain significant lipoprotein changes occurred. Thus VLDL had a high cholesterol content and a raised cholesterol to triglyceride ratio. Furthermore, the triglyceride content of low density lipoproteins (LDL) was increased. These lipoprotein abnormalities are also seen in type III hyperlipoproteinaemia. With regard both to chemical composition of VLDL and LDL and to electrophoretic mobility on agarose gel of VLDL, type III hyperlipoproteinaemia and LPbeta are similar. The possibility of a metabolic relation is discussed.

Cholesterol↗
PubMed1974

Nonreplicated DNA and DNA fragments in T4 r- bacteriophage particles: phenotypic mixing of a phage protein.

"Conservative phage" containing a genome derived from an infecting phage particle which has not undergone replication in the cell but nevertheless has become encapsulated and released in a normal phage particle, are found after infection of Escherichia coli with rII(-) or rI(-) mutants under conditions which result in rapid lysis. If such conservative phage are derived from a mixed infection with v(+) and v(1) phage, they display phenotypic mixing of the v gene product (an endonuclease carried in the phage particle). Populations of rI and rII mutant phage grown under conditions of rapid lysis include particles containing short DNA fragments. It is suggested that a "maturation defect", common to rI and rII mutants, but absent in rIII mutants, may account for the encapsulation of nonreplicated DNA as well as that of the DNA fragments.

Bacteriolysis↗
PubMed1973

Host-mediated repair of discontinuities in DNA from T4 bacteriophage.

Discontinuities of T4 DNA which are caused by excision of UV-damaged areas, by decay of (32)P atoms, or which are present in DNA from rII(-)lig(am) (-) phage produced in a host nonpermissive for amber mutants are all repaired by bacterial enzymes after infection in the presence of chloramphenicol. Escherichia coli DNA polymerase I participates in the host-mediated repair, but an approximately 20-fold variation in the levels of host polynucleotide ligase does not affect either the kinetics or the extent of repair observed. Upon removal of chloramphenicol, host-repaired DNA from UV-irradiated phage undergoes a secondary cycle of breakage, which ultimately results in solubilization of most of the phage DNA. If the cells are co-infected with nonirradiated helper phage, the secondary breaks are repaired and the continuity of the polynucleotide chain is restored. The close coincidence in the extent of primary and secondary breakage suggests that phage-coded enzymes recognize and excise areas improperly repaired by the host. In contrast to host-mediated repair, repair mediated by rescuing phage probably restored functionality to the damaged DNA.

Centrifugation, Density Gradient↗
PubMed1973

Multiple initiation of bacteriophage T4 DNA replication: delaying effect of bromodeoxyuridine.

Effects of bromodeoxyuridine (BUdR) substitutions in phage T4 DNA on the initial stages of DNA replication were investigated. Electron microscope studies of partially replicated, light (thymidine-containing) T4 DNA revealed the presence of multiple loops and forks. These DNA preparations had no BUdR in either parental or newly synthesized DNA, and the observations thus show that multiple initiation of DNA replication is a normal event in T4 development and is not caused by the presence of BUdR. A comparison of early replicative stages of light and heavy (BUdR-containing) DNA in cells mixedly infected with light and heavy T4 phage showed that early DNA synthesis occurs preferentially on the light template. Heavy and light parental DNA became associated with the protein complex of replicative DNA with equal efficiency, and there was no effect of BUdR on the net rate of DNA synthesis after infection. Newly synthesized DNA from heavy templates sedimented more slowly through alkaline sucrose gradients than did newly synthesized DNA from light templates and appeared to represent fewer replicative regions per molecule. These data indicate that BUdR substitutions in the DNA caused a slight delay in initiation but that replication of heavy DNA proceeded normally once initiated.

Bromodeoxyuridine↗