Hyperbaric pressure of 51 atmospheres is without effect on the depression of oxygen uptake in kidney tissue culture produced by halothane

Although anesthetized animals are awakened when subjected to increased pressure, compression does not result in antagonism of all phenomena associated with these drugs. It has recently been demonstrated that halothane's inhibition of respiration of isolated rat liver mitochondria is not reversed by hydraulic compression to 51 atmospheres. In order to determine whether this phenomenon can be extrapolated to the whole cell, we have investigated the effect of hydraulic compression of intact renal cells equilibrated with halothane, and conclude that pressure does not overcome the inhibitory effect of this anesthetic.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25565/1/0000107.pd

Enrichment of measles virus-like RNA in the nucleocapsid fraction isolated from subacute sclerosing panencephalitis brains

A procedure has been developed which facilitates the detection of measles virus RNA sequences in human brains. The procedure involves isolating subviral components (nucleocapsids) from brain tissues prior to RNA purification, followed by hybridization of these RNAs to cDNA synthesized from measles virus 50 S RNA template. Using these techniques we were able to obtain an RNA fraction which was manyfold enriched in measles virus-specific RNA, relative to unfractionated subacute sclerosing panencephalitis (SSPE) brain RNAs. 70-100% of the measles virus-specific RNA present in these SSPE brain samples were recovered in this enriched fraction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24061/1/0000313.pd

The Ig-Like Domain of Tapasin Influences Intermolecular Interactions

Abstract Presentation of antigenic peptides to T lymphocytes by MHC class I molecules is regulated by events involving multiple endoplasmic reticulum proteins, including tapasin. By studying the effects of substitutions in the tapasin Ig-like domain, we demonstrated that H-2Ld/tapasin association can be segregated from reconstitution of folded Ld surface expression. This finding suggests that peptide acquisition by Ld is influenced by tapasin functions that are independent of Ld binding. We also found that the presence of a nine-amino acid region in the Ig-like domain of mouse or human tapasin is required for association with Ld, and certain point substitutions in this sequence abrogate human, but not mouse, tapasin association with Ld. These data are consistent with a higher overall affinity between Ld and mouse tapasin compared with human tapasin. In addition, we found that other point mutations in the same region of the tapasin Ig-like domain affect MHC class I surface expression and Ag presentation. Finally, we showed that the cysteine residues in the Ig-like domain of tapasin influence tapasin’s stability, its interaction with the MHC class I H chain, and its stabilization of TAP. Mutagenesis of these cysteines decreases tapasin’s electrophoretic mobility, suggesting that these residues form an intramolecular disulfide bond. Taken together, these results reveal a critical role for the tapasin Ig-like domain in tapasin function.</jats:p

Studies on Prokaryotic and Eukaryotic Polynucleotide Ligases

132 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1977.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Inhibiting Effects of Enflurane and Isoflurane Anesthesia on Measles Virus Replication: Comparison with Halothane

Replication of measles virus in BSC cells was studied in the presence of enflurane (2-chloro-1,1,2-trifluoroethyl difluoromethyl ether), a commonly used volatile anesthetic agent, and its isomer, isoflurane (1-chloro-2,2,2-trifluoroethyl difluoromethyl ether). At clinical concentrations of the anesthetics (up to 4%), cell division was retarded, whereas only minimal toxic cellular effects were observed. The appearance of progeny virus from the cell cultures exposed to these anesthetics was decreased in a dose-related manner. Incorporation of [(3)H]uridine into measles virus nucleocapsids also decreased progressively with increasing anesthetic concentrations. In comparing the inhibition of measles virus replication in the presence of halothane (2-bromo-2-chloro,1,1,1-trifluoroethane), enflurane, or isoflurane, it was found that both inhibition of the appearance of infectious virus at 48 h postinfection and incorporation of [(3)H]uridine into measles virus nucleocapsids were proportional to the anesthetic concentrations. An equivalent degree of effect was produced by anesthetically equivalent concentrations of the three anesthetics (minimal alveolar concentration) but not by absolute concentrations. In addition, recovery of infectious virus synthesis from the inhibition encountered during exposure of infected BSC cells to halothane or isoflurane was also investigated. In cultures exposed to halothane or enflurane, recovery of infectious virus synthesis was rapid and complete. Recovery of virus synthesis was slower after isoflurane removal and did not reach the peak control titers of infected cultures not exposed to the anesthetic. Treatment with halothane resulted in the formation of a preponderance of slowly sedimenting virus nucleocapsid particles which contained less than full-length ribonucleic acids after anesthetic removal. Neither enflurane nor isoflurane treatment of BSC cultures resulted in the formation of significant levels of these slowly sedimenting particles with short genomes after anesthetic removal