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D L Meyer

Publications and source records attributed to D L Meyer.

At least 109 records · Page 6Linked to original sources
PubMed1978

[The influence of alcohol on central nervous compensating mechanisms following labyrinthic lesions (author's transl)].

The influence of alcohol on mechanisms compensating for labyrinthine lesions was studied in 180 guinea-pigs. The animals were subjected to either unilateral or to successive bilateral labyrinthectomy which was induced by an injection of chloroform into the middle ear. No significant influences of alcohol on vestibular compensation were found up to alcohol levels of 1g/kg. Dosages higher than 2 g/kg exerted inhibitory effects on compensation after unilateral labyrinthectomy. Compensation after successive bilateral labyrinthine lesions could not clearly be influenced. In animals which had achieved natural compensation after labyrinthectomy alcohol dosages of 0,5--1 g/kg re-elicited some of the formerly present symptoms. The data presented are interpreted with regard to their significance for the action of alcohol patients with cerebral dysfunction.

Animals↗
PubMed1977

The Mauthner-initiated startle response in teleost fish.

1. A characteristic behaviour, the 'Mauthner-initiated startle response', was recorded and quantitatively analysed with high-speed cinematography (200 frames/sec) after vibrational stimulation in 11 of 13 teleost species which possess Mauthner cells. 2. The latency of the response is 5-10 msec. This behaviour has: (a) an initial phase, the 'fast-body-bend', lasting about 20 msec and consisting of a stereotyped displacement of the head and tail to one side and (b), a second phase, the 'return-flip', consisting of a non-stereotyped flip of the tail to the opposite side. 3. Within 100 msec after the start of the Mauthner-initiated startle response, most fish were displaced 0-5-1-5 body lengths from their initial position. The variability of the animal's location after 100 msec suggests that the behaviour is adaptively non-predictable; 4. In goldfish, the Mauthner-initiated startle response could also be elicited by visual stimulation. 5. We conclude that the fast-body-bend is the direct result of activation of one Mauthner cell and its spinal motor neurone pool. 6. In four species we described examples of apparently non-Mauthner initiated startle responses.

Animals↗
PubMed1976

Radioimmunoassay of prostaglandins E1, E2, and F2alpha in unextracted plasma, serum and myocardium.

A radioimmunoassay procedure for the determination of PGE1, PGE2, and PGF2alpha is presented. The procedure involves the pre-precipitation of each prostaglandin specific antiserum with the precipitating antisera (ARGG), and the use of these antisera mixtures in assaying for PGE1, PGE2, and PGF2alpha. Applicability of the methods to unextracted plasma, serum and myocardial homogenate has been demonstrated through tests of specificity, recovery, reproducability and parallelism. A mathematical correction for cross-reactivity between PGE1 and PGE2, and their opposing antisera is given. To demonstrate the utility of the methodology in differentiation of experimental variables, prostaglandin concentrations in unincubated serum, incubated serum, and the rate of prostaglandin production in serum of dogs are given.

Animals↗
PubMed1975

Linoleate enrichment of diet and prostaglandin metabolism in rats.

Evidence that biosynthesis of prostaglandins (PG) in tissues of animals deficient in essential fatty acids is dependent on the availability of their precursors has been demonstrated. The purpose of this study was to determine the following: (1) effects of dietary linoleate enrichment on PG biosynthesis in rats; (2) effects of exogenous PGE2 and dietary linoleate on plasma free fatty acids and serum cholesterol in fed and fasted rats. Rats were fed three different concentrations of dietary linoleate as beef tallow, hydrogenated vegetable fat, or corn oil. The concentrations of PGE1 and PGF2a measured by radioimmunoassay were higher in rats fed the fed the beef tallow diet independent of energy status. A decrease in the concentration of PG between fasted and fed rats receiving hydrogenated vegetable fat is discussed in respect to the possible influence of trans isomers of unsaturated fatty acids on the biosynthesis of PG. There were significant effects of fasting on serum cholesterol concentration regardless of diet and significant interactions among effects of PGE2, fasting, and diet, suggesting regulatory effects of PGE2 on serum cholesterol concentration. The increase in plasma free fatty acids associated with fasting was prevented by PGE2 for all diets, but had the most marked effect on rats fed hydrogenated vegetable fat.

Animal Nutritional Physiological Phenomena↗
PubMedDate not supplied

Kinetics of the dissociation of indium-(p-substituted-benzyl)ethylenediaminetetraacetic acid hapten analogues from the monoclonal anti-hapten antibody CHA255.

Half-lives were measured for the dissociation of a series of 20 indium-benzyl-EDTA derivatives from a monoclonal antibody that binds to them. Most haptens gave expected monoexponential dissociation curves with half-lives ranging from approximately 8 to approximately 100 min at 22 +/- 1 degree C. Precise (+/- approximately 2.5%) determinations were made using centrifugal ultrafiltration to separate free from bound hapten. A strong pH dependence of the dissociation half-life was found for the two haptens studied. Activation enthalpies were identical (23 +/- 1 kcal/mol) for the dissociation of four haptens, suggesting that, in contrast to individual rate constants, this parameter is insensitive to hapten modification. The dissociation half-lives provided evidence for the location of a positive charge in the binding site, but gave no clear indication of the role of hydrophobic interactions or of steric requirements in hapten binding. While variations in ionic strength had no effect on the dissociation rate, lowering surface tension with dioxane increased the rate somewhat. Three hapten-antibody complexes showed biexponential dissociation rates. It is postulated that this results from distinct conformations of the complex dissociating at different rates. The dissociation rate constant was found to be an extremely sensitive indicator of the hapten-antibody interaction that can be measured very precisely.

Albumins↗
PubMedDate not supplied

A robust method for the preparation and purification of antibody/streptavidin conjugates.

The many uses of antibody-protein conjugates, especially antibody-streptavidin conjugates, give rise to the need for a reliable conjugation method offering reasonable yields and reproducible quality. We describe a method for preparing antibody-streptavidin conjugates that has consistently produced conjugates of quality and in sufficient quantity to be used in the clinical development and evaluation of the Pretarget delivery system. In this method antibody disulfides are reduced to generate reactive thiols, and maleimides are linked to streptavidin with the heterobifunctional cross-linking agent, SMCC. The two activated proteins are then mixed briefly before the conjugation is terminated with an oxidizing agent that reforms disulfides from unreacted thiols. The preponderance of the conjugate produced is 1:1 and 1:2 Ab:SA conjugate. This fraction is isolated from unconjugated proteins and high molecular weight byproduct by iminobiotin affinity and ion-exchange chromatography. The resulting conjugate is at least 90% 1:1 + 1:2 Ab:SA conjugate, contains no SA or Ab, and is produced reproducibly in 37% yield.

Animals↗