Biomedical subjects
K Carlson
Publications and source records attributed to K Carlson.
Ultracentrifugation of human lipoproteins.
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Varieties of "disordered" thinking on the Rorschach: findings in schizophrenic and nonschizophrenic patients.
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Chlamydomonas flagella. I. Isolation and electrophoretic analysis of microtubules, matrix, membranes, and mastigonemes.
Methods were developed for the isolation of Chlamydomonas flagella and for their fractionation into membrane, mastigoneme, "matrix," and axoneme components. Each component was studied by electron microscopy and acrylamide gel electrophoresis. Purified membranes retained their tripartite ultrastructure and were shown to contain one high molecular weight protein band on electrophoresis in sodium dodecyl sulfate (SDS)-urea gels. Isolated mastigonemes (hairlike structures which extend laterally from the flagellar membrane in situ) were of uniform size and were constructed of ellipsoidal subunits joined end to end. Electrophoretic analysis of mastigonemes indicated that they contained a single glycoprotein of approximately 170,000 daltons The matrix fraction contained a number of proteins (particularly those of the amorphous material surrounding the microtubules), which became solubilized during membrane removal. Isolated axonemes retained the intact "9 + 2" microtubular structure and could be subfractionated by treatment with heat or detergent. Increasing concentrations of detergent solubilized axonemal microtubules in the following order: one of the two central tubules; the remaining central tubule and the outer wall of the B tubule; the remaining portions of the B tubule; the outer wall of the A tubule; the remainder of the A tubule with the exception of a ribbon of three protofilaments. These three protofilaments appeared to be the "partition" between the lumen of the A and B tubule. Electrophoretic analysis of isolated outer doublets of 9 + 2 flagella of wild-type cells and of "9 + 0" flagella of paralyzed mutants indicated that the outer doublets and central tubules were composed of two microtubule proteins (tubulins 1 and 2) Tubulins 1 and 2 were shown to have apparent molecular weights of 56,000 and 53,000 respectively
Chlamydomonas flagella. II. The distribution of tubulins 1 and 2 in the outer doublet microtubules.
Quantitative ultrastructural analysis and quantitative gel electrophoresis of preparations of selectively solubilized Chlamydomonas outer doublets indicated that tubulins 1 and 2 were present in both the A tubule and the B tubule, and that only tubulin 1 was present in the three protofilaments which form the wall ("partition") between the lumens of the A and B tubules. The data suggested that the remaining protofilaments of the outer doublet were grouped together in pairs containing the same type of tubulin, pairs containing tubulin 1 alternating with pairs containing tubulin 2. These findings were used to construct models for the arrangement of the two tubulins in the outer doublet. Further analysis by isoelectric focusing resolved tubulins 1 and 2 into at least five bands.
Comparison of the microtubule proteins of neuroblastoma cells, brain, and Chlamydomonas flagella.
Intact A microtubules isolated from outer doublet microtubules of Chlamydomonas flagella contain two separable proteins (tubulins) that differ in molecular weight and in amino-acid composition. The microtubule protein isolated from brain or neuroblastoma cells also has two electrophoretically distinct tubulins. Although the two tubulins of brain and neuroblastoma cells are electrophoretically similar to each other, only one of these tubulins migrates with the flagellar tubulins. This is the first evidence that (a) isolated, morphologically intact, single microtubules from flagella contain at least two different tubulins, and (b) at least one of these tubulins differs from tubulins that are isolated from other sources.
Nitrogen retention of young men fed rice with or without supplementary chicken.
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Simple method for quantitive densitometry of polyacrylamide gels using fast green.
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Isolation of microtubule protein from cultured mouse neuroblastoma cells.
The addition of vinblastine to high-speed supernatants derived from homogenates of cultured mouse neuroblastoma cells results in the formation of a precipitate which has been characterized as microtubule protein by the following criteria: colchicine-binding activity, molecular weight, amino acid composition, and electrophoretic mobility. The method therefore permits the rapid isolation of microtubule protein from crude supernatants of neuroblastoma cells.
Requirements of adult human subjects for methionine and cystine.
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Physiological Streptomycin Resistance in a Multiauxotroph of Escherichia coli Strain 15 T.
Escherichia coli strain WWU was found to be moderately resistant to streptomycin when grown in a minimal medium, although the strain was sensitive if grown in nutrient broth. Transfer experiments showed that cells grown in minimal medium retain the resistant state for a period of time after dilution into nutrient broth; and conversely, sensitive cells grown in nutrient broth were sensitive after dilution into minimal medium for a period of time. The kinetics of transition from resistant to sensitive and from sensitive to resistant were observed, and kinetics of (3)H-dihydrostreptomycin accumulation by resistant and sensitive cells were compared. The data suggested that cells grown in minimal medium were physiologically resistant because they accumulated streptomycin poorly. Inactivation per incorporated antibiotic molecule was the same in resistant and sensitive cells.
Parent-to-progeny transfer and recombination of T4rII bacteriophage.
Transfer of parental, light (not substituted with 5-bromodeoxyuridine) (32)P-deoxyribonucleic acid (DNA) from rII(-) mutants of T4 bacteriophage to heavy (5-bromodeoxyuridine-substituted) progeny in Escherichia coli B was less homogeneous than in wild phages. The net transfer was 5 to 20% of the value for wild T4 phage, and the parental contribution per progeny DNA molecule amounted to 7 to 100% of the genome. Three classes could be distinguished, based on the density distribution of parental label in CsCl analysis of the progeny phages. "Far recombined" phages contain parental material only in semiconservatively replicated subunits covalently attached to progeny DNA, amounting to 5 to 10% parental contribution per genome. "Intermediate recombinants" contain, aside from conventional recombinant DNA, parental DNA banding at the original, light density. This DNA may be unattached to heavy progeny DNA or attached by weak bonds which are very sensitive to shearing during the extraction procedure. The parental contribution is 10 to 50% per progeny DNA molecule in this class. "Conservative" phages band close to the parental, light density in CsCl; their DNA is purely light. When the parental phage is labeled with both (3)H-leucine (capsid) and (32)P (DNA), the specific activity of (3)H/(32)P in the "conservative progeny" is 10 to 40% of that in the parental, showing that at least some of the (32)P in this area belongs to phages with parental DNA as the sole DNA component inside an unlabeled capsid, i.e., parental DNA which has been injected into the host and matured in a new capsid without replication or recombination. This phenomenon occurs to about the same extent in both single and multiple infection.
Cilia regeneration in Tetrahymena and its inhibition by colchicine.
The cilia of Tetrahymena were amputated by the use of a procedure in which the cells remained viable and regenerated cilia. Deciliated cells were nonmotile, and cilia regeneration was assessed by scoring the percentage of motile cells at intervals following deciliation. After a 30-min lag, the deciliated cells rapidly recovered motility until more than 90% of the cells were motile at 70 min after amputation. Cycloheximide inhibited both protein synthesis and cilia regeneration. This indicated that cilia formation in Tetrahymena was dependent on protein synthesis after amputation. Conversely, colchicine was found to inhibit cilia regeneration without affecting either RNA or protein synthesis. This observation suggested the action of colchicine to be an interference with the assembly of ciliary subunit proteins. The finding that colchicine binds to microtubule protein subunits isolated from cilia and flagella (13) supports this possibility. The potential of the colchicine-blocked cilia-regenerating system in Tetrahymena for studying the assembly of microtubule protein subunits during cilia formation and for isolating ciliary precursor proteins is discussed.
Intracellular fate of deoxyribonucleic acid from T7 bacteriophages.
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Hemodynamics associated with the diagnosis and treatment of pheochromocytoma in pregnancy.
A pregnant woman with an undiagnosed pheochromocytoma is described. Her presentation at 29 weeks' gestation was consistent with preeclampsia. Noninvasive measurement of cardiac output and ambulatory monitoring of blood pressure provided data that facilitated making the appropriate diagnosis and managing the patient until delivery at term.
Presidential address (risk management).
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Typing a blood transfusion reaction. Is it hemolytic or nonhemolytic?
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