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Biomedical subjects

C Kittel

Publications and source records attributed to C Kittel.

10 recordsLinked to original sources

Optimization of baculovirus transduction on FreeStyle293 cells for the generation of influenza B/Lee/40.

Recombinant baculovirus expression vectors derived from the Autographa californica nuclear polyhedrosis virus can serve as efficient gene-transfer vehicles for transient expression of recombinant proteins in a wide range of mammalian cell types and are able to produce multisubunit particles such as viruses or virus like particles. In this study, we constructed eight recombinant baculoviruses each containing one of the influenza B/Lee/40 virus genes in a bidirectional expression cassette for simultaneous mRNA and viral RNA transcription. Baculoviruses were transduced into FreeStyle293 in combination with the specific histone deacetylase inhibitor trichostatin A (TSA). Cotransduction conditions were optimized with a set of five baculoviruses (influenza B/Lee/40 PB1, PB2, PA, and NP and the control construct NCR-NS-minus-sense orientated encoding green fluorescent protein [rGFP]), which led to GFP expression in each host cell transduced with all five constructs. Based on the optimization with five constructs, transduction with eight baculoviruses was performed at MOI 50 and 100 with high yield stocks and 1 microM TSA and led to successful rescue of infectious influenza B/Lee/40 viruses.

Animals↗

Inhibition by prostaglandin E2 of the release of vasopressin and beta-endorphin from rat pituitary neurointermediate lobe or medial basal hypothalamus in vitro.

The present study was performed to examine the effect of the cyclo-oxygenase inhibitor, indomethacin, and that of various prostaglandins on the release of vasopressin and beta-endorphin-like immunoreactivity (beta-EI) from the rat neurointermediate lobe of the hypophysis, which was superfused in vitro. Indomethacin (2.8 and 28 mumol/l) changed neither basal secretion of vasopressin nor that evoked by electrical stimulation, whereas the resting release of beta-EI was enhanced by indomethacin (28 mumol/l). Prostaglandin (PG) E2 did not influence resting release of vasopressin but markedly inhibited (by about 50%) electrically induced release of vasopressin (least effective concentration: 300 nmol/l) as well as spontaneous secretion of beta-EI (least effective concentration: 100 nmol/l) in the presence of indomethacin (28 mumol/l). Prostaglandin F2 alpha (5 mumol/l) also inhibited the evoked release of vasopressin, whereas PGD2 (5 mumol/l) did not. Prostaglandin F2 alpha (5 mumol/l), D2 and I2 (1.5 mumol/l each) produced no effects on beta-EI release. As observed in the neurohypophysis, PGE2 inhibited the electrically induced release of vasopressin from the medial basal hypothalamus in vitro. We conclude that prostaglandins (especially PGE2) can inhibit (1) the stimulated release of vasopressin when acting on vasopressin-containing nerve terminals of either neurosecretory system (neurohypophysis, median eminence region), and (2) the secretion of beta-EI and, as can be inferred, alpha-MSH, by a direct action on intermediate lobe cells.

Animals↗

Postulational basis of the law of increase of entropy.

The law increase of entropy is shown to be a consequence of the central assumption, in the manner of Gibbs, for the construction of the ensemble that represents the physical system. It is no longer necessary to make two separate assumptions in the Gibbs-Tolman development of the bases of statistical mechanics.

Journal Article↗

Van der waals interactions and exciton condensation.

It is shown that the van der Waals interaction can lead at low temperatures to a condensed state of excitons with properties in qualitative agreement with the observations of exciton droplets. Our calculation gives a binding energy of the correct sign and magnitude for the exciton condensate. In a diclectric medium, the strong enhancement of the exciton polarizability leads to a giant van der Waals interaction, and this interaction appears to make possible a condensed exciton phase.

Journal Article↗

Vaccine potential of influenza vectors expressing Mycobacterium tuberculosis ESAT-6 protein.

We generated several attenuated recombinant influenza A vectors expressing the Mycobacterium tuberculosis early secretory antigenic target (ESAT-6) protein. The ESAT-6 protein was recently identified as one of the most promising protective antigens for cell-mediated immunity. The obtained vectors appeared to be capable of inducing ESAT-6 specific Th1 immune response in mice after intranasal immunization. We found that double immunization with two influenza vectors of different subtypes provided a significant level of protection in mice, when applied as prophylactic vaccine, as well as substantial therapeutic effect in mice with pre-established tuberculosis infection. Moreover, we found a strong synergistic effect when vaccination with Flu/ESAT-6 vectors was combined with isoniazid treatment, resulting in a dramatic reduction of bacterial load in the lungs of infected mice.

Administration, Intranasal↗