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Biomedical subjects

L L Jackson

Publications and source records attributed to L L Jackson.

33 records · Page 2Linked to original sources
PubMed1981

Embryo resorptions in mice induced by diterpene resin acids of Pinus ponderosa needles.

Ingestion of hexane extract of Pinus ponderosa needles causes reproductive failure in mice during the early stages of gestation. Virgin mice of the ICR strain were mated with males of proven fertility. The day the copulatory plug was observed was designated day 1 of gestation. Hexane extracts were administered daily via stomach tube at various concentrations and for various feeding periods. Implantation sites were stained by injections of pontamine sky blue dye on day 8 of gestation, fifteen minutes before sacrifice by cervical dislocation. Embryonic resorptions were observed in the uterus. The active components of the hexane extracts were isolated and identified as a mixture of diterpene resin acids. The diterpene resin acids are pimaric, isopimaric, sandaracopimaric, palustric/levopimaric, abietic, dehydroabietic and neoabietic acid.

Animals↗
PubMed1979

Induction of Listeria monocytogenes infection by the consumption of ponderosa pine needles.

An infectious microorganism, identified as Listeria monocytogenes, has been isolated from the bloodstream of pregnant mice fed a diet containing Pinus ponderosa needles. When the isolate was injected into pregnant mice, reproductive dysfunction and other changes, including speckled livers, spleen atrophy, and hemorrhagic intestines, appeared to mimic the signs of the disease in pregnant mice fed pine needles. Moreover, these pathological changes are similar to those observed in cattle and other mammals experiencing abortions or toxemia, or both, attributed to the ingestion of P. ponderosa needles, suggesting that L. monocytogenes may be a part of the etiology of "pine needle abortion."

Abortion, Veterinary↗
PubMed1976

Cuticular lipids of insects: VIII. Alkanes of the Mormon cricket Anabrus simplex.

The cuticular hydrocarbons of the Mormon cricket, Anabrus simplex, are all saturated and consist of n-alkanes (29+%), 3-methylalkanes (12%), internally branched monomethylalkanes (26+%), and dimethylalkanes (28+%). The principal n-alkane is the C29 component, with a range from C23 to C33. The 3-methylalkanes range from C28 to C32, and the internally branched monomethyl- and dimethylalkanes range from C29 to C39. When the branched alkanes of A. simplex are compared to those from other insects in the order Orthoptera, interesting patterns of methyl branching are observed.

Alkanes↗
PubMed1975

Incorporation of oxygen-18 into secondary alcohols of grasshopper Melanoplus sanguinipes.

Incorporation of 18-O2 and H2-18-O into the secondary alcohol moiety of wax esters in the grasshopper Melanoplus sanguinipes was determined by mass spectrometry. Results of this study show that oxygen-18 from 18-O2 was incorporated into the secondary alcohol, whereas no incorporation of oxygen-18 from H2-18-O was detected. The data suggest that the reaction, which hydroxylates n-alkanes at or near the center of the carbon chain, involves a mixed function oxidase type enzyme.

Alcohols↗
PubMed1974

Cuticular lipids of insects. VI. Cuticular lipids of the grasshoppers Melanoplus sanguinipes and Melanoplus packardii.

The cuticular lipids of the grasshoppers Melanoplus sanguinipes and Melanoplus packardii contain 60 and 68% alkanes and 28 and 18% secondary alcohol wax esters, respectively, with lesser amounts of normal and sterol wax esters, triglycerides, alcohols, sterols, and free fatty acids. All the hydrocarbons are saturated, and four types of alkanes are present: n-alkanes, 3-methylalkanes, internally branched monomethylalkanes, and internally branched dimethylalkanes. The principal n-alkanes in both insects are C(29) and C(27), with a range from C(21) to C(33). Trace amounts of 3-methylalkanes of 28, 30, and 32 total carbons are present. The principal internally branched monomethylalkanes are C(32) and C(34), whereas the main dimethylalkane contains 35 carbons. The n-alkanes do not correspond in chain length to the secondary alcohols. The primary alcohols range from C(22) to C(32) in both insects, with C(24) and C(26) predominating. The fatty acids in the triglyceride and free fatty acid fractions range from C(12) to C(24) in M. sanguinipes and from C(12) to C(18) in M. packardii.

Alkanes↗