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R Reeder

Publications and source records attributed to R Reeder.

12 recordsLinked to original sources
PubMed1983

Ventilation and CSF ions during isocapnic HCl and HNO3 acidosis in conscious rabbits.

In conscious rabbits with preimplanted arterial, central venous, and cisterna magna catheters, we infused HCl or HNO3 over 9 h to reduce plasma [HCO-3] by 9-14 mmol/l. We hypothesized that greater entry into cerebrospinal fluid (CSF) of a strong anion, NO-3 vs. Cl-, would reduce the strong ion difference and the [HCO-3], and we used isocapnic conditions to minimize the effects of PCO2-specific mechanisms of CSF HCO-3 regulation. Although CSF pH decreased slightly in both groups reflecting a small increase in CSF PCO2, we observed no significant change in CSF [HCO-3]. With HCl, there was no significant increase in CSF [Cl-], even though plasma [Cl-] increased 15-16 mmol/l. With HNO3, CSF [NO-3] increased 3.6-7.9 mmol/l, owing to the 18-22 mmol/l increase in plasma [NO-3], and resulted, not in a decrease in [HCO-3], as hypothesized, but in a decrease in [Cl-]. There was no difference in the ventilatory responses of the two groups. These results emphasize the importance of PCO2-dependent mechanisms in determining the CSF [HCO-3] and indicate that the strong anion mechanisms of CSF HCO-3 regulation can utilize changes in both NO-3 and Cl-.

Acidosis↗
PubMed1980

Ultrastructural analysis of ribosomal gene transcription in vitro.

Xenopus laevis oocyte nuclei were manually isolated and incubated in vitro to synthesize RNA. Aliquots were removed before and during the reaction and prepared for electron microscopy, in order to observe the amplified ribosomal RNA (rRNA) genes. Before in vitro incubation the rRNA transcription units are covered with close-packed RNA polymerase molecules and attached rRNP fibers, which are interpreted to have initiated in vivo. With incubation, these close-packed transcription complexes move down the gene at a rate of 2.2 nucleotides per s. Behind this close-packed region we see RNA polymerase x nascent chain complexes at about one-fifth the in vivo frequency. These are interpreted to be in vitro initiation events. After 45 min of incubation, when most of the in vivo-initiated transcripts have terminated transcription, the in vitro-initiated transcripts define the same length transcription unit seen prior to incubation. These observations are consistent with correct in vitro initiation and termination by RNA polymerases on the endogenous amplified ribosomal DNA of Xenopus laevis.

Animals↗
PubMed1976

Evaluation of the cognitive component of political issues by use of classical conditioning.

The direct use of verbal and physiological response measures to assess the cognitive component of a sociopolitical attitude is made difficult by the multiple meanings of sociopolitical stimuli. In the present study a modified differential classical conditioning procedure was used to produce an unambiguous physiological (skin conductance) response to stimuli related to a discrete social concept (black relatedness and not black relatedness). It was demonstrated that conditioned stimuli clearly related to this specific concept produced a conditioned response. The results also showed that a series of more ambiguous test stimuli related to the 1972-1974 election campaigns produced a gradient of skin conductance responses that was related to the degree of black relatedness or not black relatedness of each stimulus as measured by other means. The implications of the results of this study to further research and other indicators of the cognitive component of attitude are discussed.

Attitude↗
PubMed1965

Short- and long-lived messenger RNA in embryonic chick lens.

Cells of the embryonic chick lens pass through a definite sequence of macromolecular synthesis as they differentiate and migrate from one zone of the organ to another. Auto-radiographic studies of RNA synthesis and protein synthesis show that long-and short-lived messenger RNA's are both present in the lens.

Animals↗