We have demonstrated previously that sympathetic and vagal afferents travel in an apical-to-basal course in the heart, and can be stimulated selectively with epicardial applications of bradykinin and nicotine, respectively. In this study we tested the hypothesis that transmural myocardial infarction interrupts sympathetic and vagal afferent fibers traveling through the infarction and produces regions of afferent denervation in areas apical to the infarction. In open-chest, chloralose-anesthetized dogs, transmural myocardial infarction was created by embolizing a diagonal branch of the left anterior descending coronary artery with a vinyl latex solution that was injected directly into the artery and hardened rapidly. The transmural nature of the infarction was verified by the nitro blue tetrazolium staining technique for dehydrogenase enzymes. Epicardial applications of bradykinin (5 micrograms) and nicotine (50 micrograms) were used to stimulate chemically sensitive sympathetic and vagal afferent nerve endings, respectively. Twenty-nine dogs were studied before and 90 min after creation of transmural myocardial infarction. In 20 dogs, epicardial bradykinin applied before production of transmural myocardial infarction produced a maximal pressor response of 13 +/- 3 mm Hg 40 sec after application (p less than .01 vs preapplication values), while topical nicotine produced a maximal depressor response of 14 +/- 2 mm Hg (p less than .01 vs preapplication values) 20 sec after application at all sites tested. Ninety minutes after production of transmural myocardial infarction, epicardial sites basal to the infarction continued to respond normally to both drugs, while sites within the area of infarction and apical to the area (noninfarcted myocardium) no longer showed a pressor response to topical bradykinin or a depressor response to topical nicotine.(ABSTRACT TRUNCATED AT 250 WORDS)
Rhodobacter sphaeroides f. sp. denitrificans biotin sulfoxide reductase has been heterologously expressed in Escherichia coli as a functional 106-kDa glutathione S-transferase fusion protein. Following cleavage with Factor Xa and purification to homogeneity, the soluble 83-kDa enzyme retained biotin sulfoxide reductase activity using reduced methyl viologen or reduced benzyl viologen as artificial electron donors. Initial rate kinetics indicated a specific activity at pH 8.0 of 0.9 μmol of biotin sulfoxide reduced per min/nmol of enzyme and Km values of 29 and 15 μM for reduced methyl viologen and biotin sulfoxide reductase, respectively. Biotin sulfoxide reductase was also capable of reducing nicotinamide N-oxide, methionine sulfoxide, trimethylamine-N-oxide, and dimethyl sulfoxide, although with varying efficiencies, and could directly utilize NADPH as a reducing agent, both for the reduction of biotin sulfoxide and ferricyanide. The enzyme contained the prosthetic group, molybdopterin guanine dinucleotide, and did not require any accessory proteins for functionality. These results represent the first successful heterologous expression and characterization of a functional molybdopterin guanine dinucleotide-containing enzyme and the demonstration of reduced pyridine nucleotide-dependent biotin sulfoxide reductase activity. Rhodobacter sphaeroides f. sp. denitrificans biotin sulfoxide reductase has been heterologously expressed in Escherichia coli as a functional 106-kDa glutathione S-transferase fusion protein. Following cleavage with Factor Xa and purification to homogeneity, the soluble 83-kDa enzyme retained biotin sulfoxide reductase activity using reduced methyl viologen or reduced benzyl viologen as artificial electron donors. Initial rate kinetics indicated a specific activity at pH 8.0 of 0.9 μmol of biotin sulfoxide reduced per min/nmol of enzyme and Km values of 29 and 15 μM for reduced methyl viologen and biotin sulfoxide reductase, respectively. Biotin sulfoxide reductase was also capable of reducing nicotinamide N-oxide, methionine sulfoxide, trimethylamine-N-oxide, and dimethyl sulfoxide, although with varying efficiencies, and could directly utilize NADPH as a reducing agent, both for the reduction of biotin sulfoxide and ferricyanide. The enzyme contained the prosthetic group, molybdopterin guanine dinucleotide, and did not require any accessory proteins for functionality. These results represent the first successful heterologous expression and characterization of a functional molybdopterin guanine dinucleotide-containing enzyme and the demonstration of reduced pyridine nucleotide-dependent biotin sulfoxide reductase activity.
I show that campaign finance-based measures of ideology (CFScores) and vote-based measures of ideology (NOMINATE) have become entirely uncorrelated among Democratic legislators in the US Congress. This is not the case for Republican members of Congress or for state legislators of either party. I show this by comparing Bonica's CFScores with NOMINATE scores from 1980 to 2018 and with state legislator ideology scores (NPAT) from 1996 to 2012. The decline in correlation begins in the early 2000s and approaches zero in 2014, where it has remained since 2014. These previously undocumented results illustrate a dramatic change among Democrats in Congress in the relationship between fund-raising and voting—two activities that consume a significant portion of legislators' time and attention. Furthermore, scholars of representation need to be aware that different latent measures of ideology can lead to different conclusions about the relationship between legislators and their constituents.
This replication file contains the data and code necessary to replicate all results in “The Evolution of National Constitutions” by Scott Abramson and Michael Barber