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Biomedical subjects

M B Baird

Publications and source records attributed to M B Baird.

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

Formation of lipid peroxides in isolated rat liver microsomes by singlet molecular oxygen.

Rat liver microsomes were incubated in neutral aqueous solution of potassium peroxychromate, a system which generates singlet molecular oxygen. Such incubation resulted both in a rapid decline in NADPH-cytochrome c reductase activity, and in an increase in formation of lipid peroxides. These reactions were not inhibited by either superoxide dismutase (SOD) or mannitol, nor were they entirely duplicated by incubating microsomes with hydrogen peroxide. However, a high concentration of 1,4-diazabicyclo-[2,2,2]octane (DABCO), a known scavenger of singlet oxygen, prevented both decline in reductase activity and formation of lipid peroxides. These results suggest that the observed effects are, in fact, attributable to singlet oxygen, and not to hydrogen peroxide, superoxide radical, or hydroxyl radical.

Animals↗
PubMed1976

Pregnenolone-16alpha-carbonitrile-inducible cytochrome P450 in rat liver.

The progesterone derivative, pregnenolone-16alpha-carbonitrile, induces the synthesis of a unique cytochrome P450 peptide in hepatic microsomes of male rats. This form, detectable both spectrally and electrophoretically, is distinct from the cytochrome P450 components synthesized in response to barbiturates or polycyclic hydrocarbons, but may be identical to the major peptide in control microsomes.

Animals↗
PubMed1975

Lack of increase in DNA crosslinking in Drosophila melanogaster with age.

Adult Drosophila melanogaster fruit flies ranging in age from 2 to 7.5 weeks with a median colony survival time of 6.4 weeks at 25 degrees C showed no increase in DNA crosslinking with age. The purified denatured DNA used for crosslink determinations varied in molecular weight from 2.02 to 3.84 times 10(5) daltons and was crosslinked to the extent of 6.2-8.8% with no age-related trend.

Aging↗
PubMed1975

Loss of mitochondrial DNA with aging in Drosophila melanogaster.

The buoyant densities of nuclear and mitochondrial DNA from Drosophila melanogaster lysates has been found to show no change with increasing age in both CsCl and Cs2SO4 equilibrium density gradients. Whole fly homogenates were used to demonstrate no change in nuclear DNA content during adult life. Mitochondrial DNA increased from 1.2 to 4.3% of the total DNA during the first week of adult life and then decreased during senescence to a minimum of 1.5% at 10 weeks of age which represented a 65% loss in mitochondrial DNA content with age. These data are interpreted to support the proposal that mitochondria destruction occurs during senescence.

Aging↗
PubMed1974

Deuterium oxide effect on temperature-dependent survival in populations of Drosophila melanogaster.

A comparison of the mean life-spans for populations of Drosophila melanogaster at 10 degrees , 20 degrees , 25 degrees , and 30 degrees C maintained on media prepared with distilled water and with 50 percent deuterium oxide shows that deuteration decreases longevity at all four temperatures. The magnitude of the difference between the mean survival times of populations maintained on deuterated and nondeuterated media is inversely related to temperature between 10 degrees and 30 degrees C.

Animals↗