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Biomedical subjects

A C Olson

Publications and source records attributed to A C Olson.

At least 37 records · Page 2Linked to original sources
PubMed1977

The use of alpha-galactosidase and invertase in hollow fiber reactors.

Invertase and alpha-galactosidase have been immobilized in hollow fiber cartridges with no detectable enzyme leakage and used for the hydrolysis of sucrose and raffinose, respectively. For both hollow fiber immobilized enzymes nearly complete substrate conversion is possible. Enzyme stabilities in polysulfonate hollow fibers which have been preconditioned with bovine albumin approach the stabilities of the free enzymes.

Enzymes, Immobilized↗
PubMed1977

Electron microscopic studies of bacteriophage M13 DNA replication.

Intracellular forms of M13 phage DNA isolated after infection of Escherichia coli with wild-type phage have been studied by electron microscopy and ultracentrifugation. The data indicate the involvement of rolling-circle intermediates in single-stranded DNA synthesis. In addition to single-stranded circular DNA, we observed covalently closed and nicked replicative-form (RF) DNAs, dimer RF DNAs, concatenated RF DNAs, RF DNAs with single-stranded tails (theta, rolling circles), and, occasionally, RF DNAs with theta structures. The tails in theta molecules are always single stranded and are never longer than the DNA from mature phage; the proportion of theta to other RF molecules does not change significantly with time after infection. The origin of single-stranded DNA synthesis has been mapped by electron microscopy at a unique location on RF DNA by use of partial denaturation mapping and restriction endonuclease digestion. This location is between gene IV and gene II, and synthesis proceeds in a counterclockwise direction on the conventional genetic map.

Coliphages↗
PubMed1977

Asymphylodora atherinopsidis (Trematoda: Monorchiidae) from the California grunion, Leuresthes tenuis, including a redescription.

Asymphylodora (Asymphylodoroides) atherinopsidis from the California grunion, Leuresthes tenuis, a new host record, and jacksmelt, Atherinopsis californiensis, the type host, is redescribed and illustrated using more symmetrical as well as larger and smaller specimens than the holotype. The geographic distribution is extended from the type locality of Stinson Beach, Marin Co., California to Estero Beach, 10 km south of Ensenada, Baja California Norte, Mexico. Two tubular externat seminal vesicles opening independently into the internal seminal vesicle are reported apparently for the first time in a trematode. The genital pore is at the left posterolateral margin of the acetabulum which is midway between the lateral margins. Worms may grow to a length of 5.6 mm but eggs were present in one specimen 1.3 mm long.

Animals↗
PubMed1976

DNA replication in Chinese hamster ovary cells made permeable to nucleotides by tween-80 treatment.

We have developed a method for permeabilizing CHO cells to nucleotides under conditions which allow most cells to remain viable. Permeabilized cells can carry out ATP-dependent, semiconservative synthesis of DNA. The data are consistent with the continuation of DNA synthesis in those cells in S phase at the time of treatment, possibly limited to completion of replicon synthesis without new initiations.

Cell Line↗
PubMed1976

Hydrogen production in the rat following ingestion of raffinose, stachyose and oligosaccharide-free bean residue.

Raffinose and stachyose were compared to cooked California Small White beans (CSW) containing 4% alpha-oligosaccharides (stachyose and raffinose) and to oligosaccharide-free CSW solids (residue from hexane and 70% ethanol extraction of CSW) as sources of hydrogen when ingested by rats maintained in life support systems. If the oligosaccharide content were the only hydrogen source in CSW, it would have had to be 25 times as potent as CSW, but raffinose was only five times and stachyose seven times as potent as CSW. Oligosaccharide-free residue was 0.4 to 0.5 as active as CSW. Hydrogen producing potencies of stachyose and raffinose were enhanced by feeding in combinations with residue. The increases in hydrogen production from the combinations were more than additive. Thus, CSW contains at least one 70% alcohol-insoluble substance which, in addition to the oligosaccharides, is essential to bring about quantitatively the physiological response to whole beans observed in rats.

Animals↗
PubMed1969

Plant suspension culture media macromolecules-pectic substances, protein, and peroxidase.

Macromolecules secreted into the media by a nondifferentiating suspension culture of tobacco cells were found to be composed of protein and polysaccharide, and to account for the viscosity of the media. The concentration, composition, and viscosity of these macromolecules changed significantly with the age of the culture and growth temperature. The concentration changed from 0.02 mg/ml in newly inoculated cultures to over 1 mg/ml in older cultures. The macromolecules contained from 6 to 18% protein and 3 to 4 mumoles hydroxy-proline/mg nitrogen, more than 20 times the level found in whole cells. The macromolecules contained 5 to 25% pectic substances whose carboxyl groups were either methyl esterified or combined with calcium. Arabinose, xylose, glucose, galactose, and mannose were identified in acid hydrolysates of the macromolecules. Peroxidase activity of the macromolecules increased as cultures became older. Peroxidase isoenzyme patterns changed with culture age and growth temperature. The relation of the macromolecules to cell walls and intercellular substances is discussed.

Journal Article↗