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The Mr values for aspartate carbamoyltransferase (ACTase) from nine species were determined by gel filtration on Sephacryl S-200. The mean value was 104 000 and there was no evidence for differing size classes of plant ACTase. At 200 mmol m−3, the only nucleotide which caused any inhibition was UMP; there was no evidence for differing patterns of nucleotide regulation. Ornithine carbamoyltransferase (OCTase) was isolated from eight species and the Km values for ornithine and carbamoyl phosphate were determined. The Km values for ornithine ranged from 0.3 mol m−3 to 3.0 mol m-3; the Km values for carbamoyl phosphate ranged from 0.11 mol m−3 to 0.55 mol m−3. The Mr values for the various OCTase isolates were determined by gel filtration on Sephacryl S-200 and ranged from 148 000 to 167 000 with a mean of 158 000. When pure wild oat OCTase was subjected to SDS—PAGE analysis, a single protein of Mr 38 000 was detected. These values are consistent with a tetrameric structure for OCTase. We have demonstrated N-(phosphonacetyl)-L-aspartate (PALA) and N-(phosphonacetyl)-L-ornithine (PALO) to be very potent in vitro inhibitors of plant ACTase and OCTase, respectively. Of the seven species tested, the K1 values for PALA ranged from 30 μmol m−3 to 100 μmol m−3 and those for PALO ranged from 170 umol m−3 to 350 μmol m−3; the inhibition was competitive with carbamoyl phosphate as the variable substrate. Although PALA and PALO were very potent in vitro inhibitors, they were poor herbicides. Mechanisms are discussed which may account for the lack of herbicidal activity of PALA and PALO.

Competing Interests: The authors declare that there are no conflicts of interest.

Competing Interests: The view(s) expressed herein are those of the authors and do not reflect the official policy or position of Brooke Army Medical Center, the US Army Medical Department, the US Army Office of the Surgeon General, the Department of the Air Force, the Department of the Army, the Department of Defense, or the US Government.

The American College of Cardiology, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, and American Association for Thoracic Surgery, along with key specialty and subspecialty societies, have completed a 2-part revision of the appropriate use criteria (AUC) for coronary revascularization. In prior coronary revascularization AUC documents, indications for revascularization in acute coronary syndromes and stable ischemic heart disease (SIHD) were combined into 1 document. To address the expanding clinical indications for coronary revascularization, and to align the subject matter with the most current American College of Cardiology/American Heart Association guidelines, the new AUC for coronary artery revascularization were separated into 2 documents addressing SIHD and acute coronary syndromes individually. This document presents the AUC for SIHD.Clinical scenarios were developed to mimic patient presentations encountered in everyday practice. These scenarios included information on symptom status; risk level as assessed by noninvasive testing; coronary disease burden; and, in some scenarios, fractional flow reserve testing, presence or absence of diabetes, and SYNTAX score. This update provides a reassessment of clinical scenarios that the writing group felt were affected by significant changes in the medical literature or gaps from prior criteria. The methodology used in this update is similar to the initial document but employs the recent modifications in the methods for developing AUC, most notably, alterations in the nomenclature for appropriate use categorization.A separate, independent rating panel scored the clinical scenarios on a scale of 1 to 9. Scores of 7 to 9 indicate that revascularization is considered appropriate for the clinical scenario presented. Scores of 1 to 3 indicate that revascularization is considered rarely appropriate for the clinical scenario, whereas scores in the mid-range of 4 to 6 indicate that coronary revascularization may be appropriate for the clinical scenario.As seen with the prior coronary revascularization AUC, revascularization in clinical scenarios with high symptom burden, high-risk features, and high coronary disease burden, as well as in patients receiving antianginal therapy, are deemed appropriate. Additionally, scenarios assessing the appropriateness of revascularization before kidney transplantation or transcatheter valve therapy are now rated. The primary objective of the AUC is to provide a framework for the assessment of practice patterns that will hopefully improve physician decision making.

The American College of Cardiology, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, and American Association for Thoracic Surgery, along with key specialty and subspecialty societies, have completed a 2-part revision of the appropriate use criteria (AUC) for coronary revascularization. In prior coronary revascularization AUC documents, indications for revascularization in acute coronary syndromes (ACS) and stable ischemic heart disease were combined into 1 document. To address the expanding clinical indications for coronary revascularization, and in an effort to align the subject matter with the most current American College of Cardiology/American Heart Association guidelines, the new AUC for coronary artery revascularization were separated into 2 documents addressing ACS and stable ischemic heart disease individually. This document presents the AUC for ACS. Clinical scenarios were developed to mimic patient presentations encountered in everyday practice and included information on symptom status, presence of clinical instability or ongoing ischemic symptoms, prior reperfusion therapy, risk level as assessed by noninvasive testing, fractional flow reserve testing, and coronary anatomy. This update provides a reassessment of clinical scenarios that the writing group felt to be affected by significant changes in the medical literature or gaps from prior criteria. The methodology used in this update is similar to the initial document but employs the recent modifications in the methods for developing AUC, most notably, alterations in the nomenclature for appropriate use categorization. A separate, independent rating panel scored the clinical scenarios on a scale of 1 to 9. Scores of 7 to 9 indicate that revascularization is considered appropriate for the clinical scenario presented. Scores of 1 to 3 indicate that revascularization is considered rarely appropriate for the clinical scenario, whereas scores in the mid-range (4 to 6) indicate that coronary revascularization may be appropriate for the clinical scenario. Seventeen clinical scenarios were developed by a writing committee and scored by the rating panel: 10 were identified as appropriate, 6 as may be appropriate, and 1 as rarely appropriate. As seen with the prior coronary revascularization AUC, revascularization in clinical scenarios with ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction were considered appropriate. Likewise, clinical scenarios with unstable angina and intermediate- or high-risk features were deemed appropriate. Additionally, the management of nonculprit artery disease and the timing of revascularization are now also rated. The primary objective of the AUC is to provide a framework for the assessment of practice patterns that will hopefully improve physician decision making.