Search PubMed⌕ Search

Biomedical subjects

P Pfeiffer

Publications and source records attributed to P Pfeiffer.

At least 163 records · Page 9Linked to original sources
PubMed1985

IgE synthesis in vitro during infection of mice with the nematode Nippostrongylus brasiliensis: effects of mitogens and antigens.

In vitro IgE synthesis by lymphoid cells was studied during the course of infection of mice with Nippostrongylus brasiliensis. The studies involved inbred strains of mice which had been shown to be high IgE responders (A.CA, B10.M), or non-responders (Balb/c, B10.D2) to parasite antigen. In addition, F1 hybrids of low and high responders and irradiated non-responders were studied. Infection with N. brasiliensis led to an increase in IgE synthesis in vitro which was most pronounced during reinfection of mice. Addition of mitogens e.g. pokeweed mitogen (PWM), lipopolysaccharide (LPS), concanavalin A (ConA) to the cultures induced enhancement, suppression or had no effect on IgE synthesis. Addition of N. brasiliensis homogenate or worm culture supernatant led to a fluctuating pattern of IgE synthesis. No correlation was found between lymphocyte proliferative response to mitogen and worm antigens and IgE synthesis. Our data suggest, that PWM is more likely to enhance IgE synthesis in vitro than LPS or ConA. An enhancement is more easily observed with the cells of non-infected animals or during the early phase of infection or reinfection. The mitogen-induced increase in IgE synthesis did not exceed the values obtained during infection or reinfection.

Animals↗
PubMed1985

[High performance liquid chromatographic determination of organic acids, sugars, glycerin and alcohol in wine on a cation exchange resin].

The main constituents of wine (ethanol, glycerol, glucose, fructose, tartrate, malate, lactate, succinate, acetate and citrate) were separated by HPLC in one run and determined quantitatively in a time of 25 min. The stationary phase was the cation exchange resin HPX 87H and the mobile phase was dilute sulfuric acid. The results of the HPLC analysis of several wines are presented. Good agreement is observed with the results obtained by conventional methods.

Acids↗
PubMed1985

[Motor, sensory electroneurographic and electromyographic results as well as somatosensory evoked potentials in comparison to clinical findings following nerve suture].

A group of 37 patients (total 41 nerves) with a traumatic transection of median or ulnar nerves at the wrist were reinvestigated clinically and electrophysiologically 4-59 months after primary or secondary suture or grafting. Clinically there was no relation between the time after the operation, and sensory recovery determined according to the schedule of Nicholson and Seddon (1957), two-point discrimination, vibration threshold. There was also no relationship between the time after suture, and the motor latencies as well as amplitudes of evoked muscle action potentials from the abductor pollicis brevis or hypothenar muscles. In sensory nerve fibres there was a statistically significant increase of the maximum amplitude and of the cumulative amplitude during the period after operation, due to an increasing number of regenerated nerve fibres. Sensory nerve conduction velocities showed no relation to the time after suture. Cumulative amplitudes were significantly related to two-point discrimination and to restitution of sensibility. As indicated by the great scatter, however, this parameter is merely a moderate predictor for the degree of clinical recovery. Somatosensory evoked potentials can be helpful in some cases to indicate nerve regeneration when nerve action potentials in peripheral nerves cannot be recorded. However, latencies and amplitudes of the individual peaks did not reveal any relationship to either clinical findings or to period of time after operation. Needle electromyography also yielded highly variable findings. A constant finding was a persistent loss of motor units. Most of these were increased sin size, as indicated by prolonged duration of their action potentials during slight voluntary effort.

Adolescent↗
PubMed1985

Effect of thiol-activated toxins (streptolysin O, alveolysin, and theta toxin) on the generation of leukotrienes and leukotriene-inducing and -metabolizing enzymes from human polymorphonuclear granulocytes.

The generation of leukotrienes (LTC4, LTD4, LTE4, and LTB4; 12-epi-LTB4 isomer) from human granulocytes by thiol-activated toxins (streptolysin O, alveolysin from Bacillus alvei, and theta toxin from Clostridium perfringens) is described. The release occurs under noncytolytic conditions. Although LTB4 is the major component after calcium ionophore stimulation, more LTC4 as compared with LTB4 is released with the toxins. The 5-lipoxygenase pathway of toxin-mediated activation can effectively be inhibited by caffeic acid, a lipoxygenase inhibitor. The toxins also induce the release of leukotriene-metabolizing enzymes such as gamma-glutamyltranspeptidase, which transfers LTC4 into LTD4, and dipeptidase, which metabolizes LTD4, into LTE4. Dipeptidase activity is more pronounced than the gamma-glutamyltranspeptidase activity but still does not reach the levels obtained when cells were triggered with opsonized zymosan.

Arachidonate Lipoxygenases↗
PubMed1985

The role of immunoglobulin E receptors in allergic diseases.

Recent studies presented evidence that subpopulations of lymphocytes, monocytes and eosinophils carry immunoglobulin (IgE)-specific membrane receptors which differ from the classical Fc epsilon-receptors on basophil granulocytes and mast cells. The analysis of IgE-receptor interactions with various cells has led to important insights as to the requirements of IgE-antibody regulations. In addition, the membrane biochemical mechanisms in the induction of mediator release became better understood. The expression of low affinity receptors on lymphocytes appears to by intimately involved in the generation of IgE enhancing and suppressive factors. In future, these molecules might be available for immunotherapy. A summary of the recent knowledge combined with our data is presented.

Animals↗
PubMed1984

Comparison of the killer toxin of several yeasts and the purification of a toxin of type K2.

A total of 13 killer toxin producing strains belonging to the genera Saccharomyces, Candida and Pichia were tested against each other and against a sensitive yeast strain. Based on the activity of the toxins 4 different toxins of Saccharomyces cerevisiae, 2 different toxins of Pichia and one toxin of Candida were recognized. The culture filtrate of Pichia and Candida showed a much smaller activity than the strains of Saccharomyces. Extracellular killer toxins of 3 types of Saccharomyces were concentrated and partially purified. The pH optimum and the isoelectric point were determined. The killer toxins of S. cerevisiae strain NCYC 738, strain 399 and strain 28 were glycoproteins and had a molecular weight of Mr = 16,000. The amino acid composition of the toxin type K2 of S. cerevisiae strain 399 was determined and compared with the composition of two other toxins.

Amino Acids↗