PubMed Health⌕ Search

Biomedical subjects

B Lindner

Publications and source records attributed to B Lindner.

79 records · Page 5Linked to original sources
PubMed1975

Differences in occipital cortical synapses from environmentally enriched, impoverished, and standard colony rats.

Initial and replication experiments were studied with littermate, S1, male rats 25-55 days of age placed in enriched (EC), standard colony (SC), and impoverished (IC) environments. Measurements of the length of postsynaptic thickenings were taken from asymmetrical axodendritic synapses in layer IV of the dorsal medial occipital cortex. This experiment differed from others of this nature, for animals from both experimental conditions were compared with the standard colony animals. The 8% (p less than 0.01) difference in postsynaptic thickening length between 675 synapses from EC and 680 synapses from IC was primarily due to the IC, as can be seen by comparing both with the SC. The number of synapses per unit area of neuropil was 15% (p less than 0.01) more in the IC than in the EC and this difference was primarily due to impoverishment. Both the original and the replication experiment verified this direction of change. Thus, environmental experience does significantly affect synaptic length and number, although the large magnitude previously reported by Mphillgaard et al. (1971) was not confirmed in the present experiments. The 7% cortical depth difference between the enriched and impoverished animals was seen to be attributed to both conditions when each was compared with the standard colony rats. The plasticity of synaptic dimensions is discussed in relation to our previous work and to work of others.

Animals↗
PubMedDate not supplied

[The cause of loosening in cemented hip joint prostheses. Light and electron microscopy study and laser microprobe mass analysis].

Aseptic loosening of joint prostheses is a quantitatively increasing problem. For evaluation of the pathogenesis of prosthesis loosening joint capsules and tissue membranes taken from the femoral and acetabular bone-cement-interface of 23 hips revised for aseptic loosening were examined. In all cases we found an excessive inflammatory histiocytic reaction with intracytoplasmatic incorporation of a small granular foreign material. This could be identified to be zirconium oxide by LAMMA-analysis. Zirconium oxide and polymethylmethacrylate (PMMA) wear particles could be shown in the cytoplasm of histiocytes by transmission electron microscopy. By quantitative grading of the histiocytic reaction and the intracellular granular wear particles we found that both were evenly distributed around the loosened prosthesis. Chronic inflammation due to bone cement abrasion is regarded as a leading cause of aseptic prosthesis loosening.

Adult↗
PubMedDate not supplied

Chemical structure and biologic activity of bacterial and synthetic lipid A.

The chemical structure of the lipid A component of enterobacterial lipopolysaccharide (LPS) is now known in some detail. For example, lipid A of Escherichia coli consists of a beta(1----6)-linked D-glucosamine disaccharide that carries four (R)-3-hydroxytetradecanoyl groups in positions 2, 3, 2', and 3' and two phosphoryl residues in positions 1 and 4'. The hydroxy fatty acids at positions 2' and 3' are acylated at their 3-hydroxyl groups by dodecanoic acid and tetradecanoic acid, respectively. The hydroxyl groups in positions 4 and 6' are free, the latter serving as the attachment site for the polysaccharide component in intact LPS. On the basis of this structure, E. coli-type lipid A and partial structures thereof have been chemically synthesized (group of T. Shiba, Osaka University, Osaka, Japan) and analyzed for endotoxic activity. In all in vivo and in vitro test systems employed (including lethal toxicity, pyrogenicity, local Shwartzman reactivity, B lymphocyte mitogenicity, macrophage activation, and serologic cross-reactivity with lipid A antiserum), synthetic lipid A has activity identical to that of E. coli lipid A. These findings support the structural proposal for lipid A and prove the previous hypothesis that the endotoxic principle is embedded in lipid A.

Animals↗
PubMedDate not supplied

Hypochlorite adulteration of urine causing decreased concentration of delta 9-THC-COOH by GC/MS.

Marijuana is confirmed and quantitated in urine as 11-nor-delta 9-THC-9-COOH by GC/MS in the selected ion monitoring mode after extraction from urine. The addition of varying amounts of household bleach causes significant decreases in the quantitated amounts of tetrahydrocannabinol (THC). Urine samples containing various known amounts of THC (25-219 ng/mL) were spiked with increasing amounts of household bleach (0-64 microL/mL of urine). The samples were extracted using a solid-phase extraction procedure, derivatized, and analyzed by GC/MS. The area counts for the deuterated internal standard versus the native drug, as well as the quantitation for the various spiked samples, were compared with those of the non-adulterated samples. The results demonstrated that there was an inverse relationship between the amount of bleach used and the amount of THC recovered. The area counts for both the deuterated and native THC decreased as the amount of bleach increased. There appeared to be a consistent decrease in the ratio of native to deuterated THC, suggesting that the bleach affected the native drug more than the deuterated compound. The same decrease in THC concentrations were noted when the samples were assayed by an RIA methodology (Roche Abuscreen) as well as by an FPIA assay (Abbott TDx).

Dronabinol↗