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Biomedical subjects

R W Miller

Publications and source records attributed to R W Miller.

At least 163 records · Page 9Linked to original sources
PubMed1980

Three-dimensional perspective of U.S. cancer mortality.

Data from U.S. death certificates, 1950--77, can now be displayed as computer-generated three-dimensional graphs. The results provide a panoramic view of the rise and fall in cancer rates by age, sex, and calendar year for Whites and non-Whites. Sample graphs depict the rising rates for lung cancer, the falling rates for stomach cancer, the relatively constant rates for breast cancer, and the dramatic change in rates for childhood leukaemia.

Adolescent↗
PubMed1980

Spin-label Studies of Membranes in Rye Protoplasts during Extracellular Freezing.

Protoplasts isolated from epicotyls of nonhardened winter rye seedlings were spin-labeled with the N-oxyl-4-4-dimethyloxazolidine derivatives of 5-ketostearic (5NS) and 16-ketostearic (16NS) acids. Spectra of the membrane-bound labels showed motional broadening with a rotational correlation time of 1.5 x 10(-8) second for 5NS and 1.5 x 10(-10) second for 16NS at 0 C. A procedure was developed to follow membrane changes in these protoplasts during extracellular freezing. With freezing, molecular motion of 5NS, but not of 16NS, spin probes was restricted. The increase in molecular order near the hydrated end of the membrane did not result from lowered temperatures inasmuch as no such change was observed in supercooled samples. These changes are probably due to dehydration of protoplast membranes during extracellular freezing. Similar results were obtained with multilayered egg yolk lecithin and are consistent with previous observations of changes in lecithin multibilayers during dehydration. Such alterations in membrane order might lead to irreversible membrane damage during extracellular freezing of plant cells.

Journal Article↗
PubMed1980

Lipid involvement in oleoyl CoA desaturase activity of Fusarium oxysporum microsomes.

Desaturation of oleoyl CoA by the microsomal fraction of Fusarium oxysporum hyphal cells required O2, NADPH, MgCl2, and the addition of either bovine serum albumin or the 105 000g supernatant fraction. In the absence of reduced nucleotide, [14C]oleoyl CoA was rapidly incorporated into phospholipid and triacylglycerol and hydrolyzed to free fatty acids. After addition of NADPH, oleate was desaturated at the normal rate. Analysis of the distribution of [14C]oleate and [14C]linoleate between different lipid classes revealed that phosphatidylcholine and phosphatidylethanolamine were labeled with [14C]linoleate before any other lipid class. These results are consistent with oleoyl phospholipid being a direct intermediate in the desaturation of oleoyl CoA. The preference of the oleoyl-desaturase for NADPH, the relatively high pH optimum of 8.2, and the sensitivity to thenoyltrifluoroacetone inhibition suggest that some components of the microsomal electron-transport chain are common to both the oleoyl desaturase and stearoyl CoA desaturase systems in this fungus.

Fatty Acid Desaturases↗
PubMed1980

Catalysis of exchange of terminal phosphate groups of ATP and ADP by purified nitrogenase proteins.

A crude Azotobacter nitrogenase complex contained a highly active adenylate kinase which caused rapid equilibration of AMP, ADP, and ATP. Purified molybdenum-iron protein preparations also contained measurable adenylate kinase activity which could be removed by adsorption and elution from hydroxylapatite. Independent of adenylate kinase, the highly purified molybdenum-iron protein from both Klebsiella pneumoniae and Azotobacter chroococcum catalyzed the exchange of [32P]orthophosphate with the terminal phosphate of ATP or ADP. The exchange labeling of ATP was stimulated by ferricyanide ion due to the inhibition of ATP hydrolysis linked to substrate reductions which cannot occur in the absence of reductant. This exchange reaction is responsible for reported ATP synthesis by crude nitrogenase preparations. Binding of ATP labeled with 32P in the terminal phosphate group was measured directly with concentrated solutions of the molybdenum-iron nitrogenase protein from K. pneumoniae by the column gel filtration method. The protein was saturated with ATP at a calculated ratio of 4.0 +/- 0.3 mol ATP/mol protein; half-saturation of 220 microM protein occurred at 600 +/- 100 microM. The interactions between adenine nucleotides and the molybdenum-iron protein suggest the involvement of the nucleotides in a role distinct from the established reactions with the iron protein of the nitrogenase complex. A dual role for ATP in the reduction of dinitrogen by isolated nitrogenase proteins would be consistent with the existence of binding sites for ATP on both the iron and molybdenum-iron proteins.

Adenosine Diphosphate↗
PubMed1980

Temperature-induced physical changes in fungal plasma membranes.

Ordered structures suggesting phase separation of lipids were observed in freeze-fracture replicas of plasma membranes of Fusarium sulphureum after free protoplasts had been fixed at 0 degrees C. Areas representing up to 50% of the protoplast plasma membrane inner fractured face assumed a lateral, hexagonally ordered structure from which the normally randomly distributed 25-nm membrane protein complexes had been excluded. Intact macroconidia only rarely showed small regions of lateral ordering of this type when fixed at the same, nonlethal temperature. The normal impermeability of the macroconidial plasma membrane to divalent cations such as Ni2+ declined rapidly when the cells were incubated at temperatures 5 degrees C or more above the physiological growth temperature range of the organism. Admission of divalent cations and death of the cells was associated with an irreversible thermotropic change in the fluidity in the membrane lipids as indicated by lipophilic spin probes. Partitioning spin probe and freeze-fracture techniques were best suited to the observation of thermotropic physical changes in the fungal plasma membrane which were induced at supra- and sub-physiological temperatures, respectively.

Cations, Divalent↗
PubMed1980

Rx with a dose of info.

Information similar to that provided to physicians will be available to patients who get new prescriptions for 10 drugs, as part of a 3-year pilot program of the Food and Drug Administration. The information, in leaflet form, is to be handed out to the customer at the time the prescription is filled. Included will be possible side effect, proper uses for the drug, and any precautions in taking the particular medicine.

Drug Labeling↗
PubMed1979

US cancer incidence and mortality in the first year of life.

Based on the Third National Cancer Survey (1969 to 1971), the incidence of malignant neoplasms in the United States was 183.4 per million live births per year in infants younger than 1 year and 36.5 in newborns younger than 29 days. In both age groups, neuroblastoma was the most commonly diagnosed neoplasm. Overall, cancer incidence in infants younger than 1 year was almost 3.5 times greater than mortality determined from US death certificates from 1960 to 1969. For individual tumor types, the ratio between incidence and mortality varied between 159 for retinoblastoma and 1.5 for leukemia largely reflecting relative differences in survival due to treatment.

Central Nervous System Diseases↗
PubMed1979

Statistics and biomedical research.

Medical observations of leukemia or Hodgkin's disease clusters in time and space have led statisticians to invent techniques to evaluate the probability that these occurrences were due to chance. A difficult computation in human genetics was simplified by a matrix devised by a non-genetical statistician, and readily adapted to newly emerging computer-processing. The experiences exemplify the special opportunity in Japan to enhance research by merging mathematical talent with biomedical observations.

Computers↗