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Massive stars are a major source of chemical elements in the cosmos, ejecting freshly produced nuclei through winds and core-collapse supernova explosions into the interstellar medium. Among the material ejected, long-lived radioisotopes, such as 60 Fe (iron) and 26 Al (aluminum), offer unique signs of active nucleosynthesis in our galaxy. There is a long-standing discrepancy between the observed 60 Fe/ 26 Al ratio by γ-ray telescopes and predictions from supernova models. This discrepancy has been attributed to uncertainties in the nuclear reaction networks producing 60 Fe, and one reaction in particular, the neutron-capture on 59 Fe. Here we present experimental results that provide a strong constraint on this reaction. We use these results to show that the production of 60 Fe in massive stars is higher than previously thought, further increasing the discrepancy between observed and predicted 60 Fe/ 26 Al ratios. The persisting discrepancy can therefore not be attributed to nuclear uncertainties, and points to issues in massive-star models., (© 2024. The Author(s).)

Objectives: To determine the short- and long-term outcomes of patients treated operatively for Takayasu's arteritis and the effect of disease activity on results., Methods: Forty-two (17%) of the 251 patients enrolled in our Takayasu's arteritis registry between 1975 and 2002 required operation for symptomatic disease. Data were obtained from the registry, patient records, phone correspondence, and written surveys., Results: There were 38 females and 4 males with a median age of 29 years (range, 12 to 56 years), and 32 (76%) were white. Sixty operations were performed for symptomatic disease. The mean duration of symptoms before operation was 5.6 months (range, 0 to 25 months). Thirteen (31%) patients had active disease and underwent operation for acute presentation or failure of medical management. Thirty-nine patients (93%) had operation for occlusive disease. Twenty-two (52%) patients had involvement of both the great and abdominal aortic branch vessels; 10 (24%) had great vessel disease alone; 9 (21%) had involvement of abdominal arteries; and 1 (2%) had coronary artery disease. There was no operative death, myocardial infarction, major stroke, or renal failure. Three patients had early graft thrombosis, two had a minor stroke, and two developed hyperperfusion syndrome. The median follow-up was 6.7 years (range, 1 month to 19.3 years). Eleven (26%) patients required 15 graft revisions; five of the patients had active disease at the time of initial operation. All early revisions (<1 year) were in patients with active disease. By Kaplan-Meier analysis, freedom from revision at 5 and 10 years was 100% in patients with quiescent disease not requiring steroids (group I, n = 5, 12%), 95% and 81% in patients whose disease was quiescent on steroids (group II, n = 24, 57%), 57% in patients with active disease on steroids (group III, n = 7, 17%), and 33% in patients with active disease and no long-term steroids (group IV, n = 6, 14%) (P < .006). The rate of revision or progression of disease at another site in 5 years was 0% in group 1, 10% in group 2, 57% in group 3, and 67% in group 4 (P < .001) The differences were even more pronounced when an analysis was done on the basis of disease activity alone, irrespective of steroid use. During the follow-up period, 3 of 39 great vessel, 2 of 18 mesenteric/renal, and 1 of 9 aortofemoropopliteal reconstructions occluded. The predicted mortality for patients was 4% at both 5 and 10 years (95% CI) respectively (confidence interval [CI], 0% to 11%) and 10 (CI, 0% to 14%) years, respectively., Conclusions: The minority of patients with Takayasu's arteritis require operation. In our predominantly white female patient population, occlusive symptoms were the most common indication for operation. Operation for these selected patients was safe, with no operative mortality, myocardial infarction, major stroke, or renal failure. Patients with active disease requiring operation are more likely to require revision or develop progressive symptomatic disease at another site. Long-term survival is excellent, regardless of disease activity at the time of operation.

Carotid body tumors (CBT) are rare and usually benign neoplasms (60%-90%), originating from the mesoderm and neural ectoderm. In view of the extensive and unrelenting growth of unresected CBT, encasing vital neurovascular structures, and the significant incidence of malignancy (> or = 10%), surgical excision is the standard treatment of choice. Despite progress in CBT imaging and surgical technique, cranial nerve deficit, stroke, and death continue to affect 10% to 40% of patients undergoing curative surgical resection, particularly in large tumors proximal to the skull base. In such cases, CBT shrinkage by preoperative embolization, improved surgical access utilizing mandibular subluxation, and electroencephalographic monitoring combined with meticulous surgical technique may enable curative tumor resection, without prohibitive morbidity. In light of associated disability, preoperative acknowledgment of the ever-present substantial risk of cranial nerve injury cannot be overemphasized. We report on a patient with a large symptomatic CBT treated surgically with the aid of mandibular subluxation and preoperative embolization.

We report a patient treated for infection of an ascending aorta to bilateral common carotid artery bypass graft. The superficial femoral arteries were used for the reconstruction after local treatment failed. The patient is free from infection and the grafts are patent 4 years after operation. We believe this is the only report in the literature in which the superficial femoral arteries were used to reconstruct an infected great vessel graft.

Upper extremity vascular injuries are common in trauma. The mortality rate from these injuries is quite low; however, the morbidity rate is quite significant. Prompt diagnosis and treatment can reduce the amputation rate for these injuries to minimal. Furthermore, morbidity from late complications of chronic ischemia, restenosis, and cold intolerance can be decreased as well. Fasciotomy, although less frequently required than in lower extremity injuries, should be used in all cases of suspected compartment syndrome.

Vasomotor tone is the end result of a complex set of interactions that control relaxation and contraction of blood vessels. The critical role of nitric oxide (NO) in modulating vasomotor tone has become increasingly apparent over the last 15 years. A phenomenal amount of resources have been invested in the study of this simple molecule, and the volume of scientific literature that has resulted is astounding. In this review, we discuss the pertinent physiology and biochemistry of NO as it relates to the control of vasomotor tone. Methods of measuring NO in basic science and clinical settings are outlined, and the derangements of endothelial NO production and release (endothelial dysfunction) in pathophysiologic and disease states are discussed. Finally, potential therapies aimed at preserving endothelial function and augmenting NO production also are reviewed.

Spin trapping of free radicals during the hepatic metabolism of tamoxifen was investigated; the spin trap employed in this study was 5,5-dimethyl-1-pyrroline-1-oxide (DMPO). The spin adduct 2-hydroxy-5,5-dimethyl-1-pyrrolidinyloxyl (DMPO-OH) was detected in an in vitro incubation mixture of phenobarbital-treated rat hepatocytes containing tamoxifen, dimethyl sulfoxide, and DMPO. However, since the spin adduct 2,5,5-trimethyl-1-pyrrolidinyloxyl (DMPO-CH3) was not observed, the DMPO-OH resulted from the cellular bioreduction of 2-hydroperoxy-5,5-dimethyl-1-pyrrolidinyloxyl (DMPO-OOH) by glutathione peroxidase. Addition of superoxide dismutase (SOD) to the in vitro system indicated that superoxide production was intracellular. When noninduced hepatocytes were utilized, free radical production was not evident. Thus, the cytochrome P450 monooxygenase system was responsible, in part, for the intermediacy of superoxide anion during hepatic metabolism.

Experiments were conducted to determine which free radicals are generated during the metabolism of adriamycin (ADM) by canine tracheal epithelial (CTE) cells, guinea pig enterocytes, and rat hepatocytes. The technique employed in this study was spin trapping; the spin trap utilized was 5,5-dimethyl-1-pyrroline-1-oxide (DMPO). The spin adduct 2-hydroxy-5,5-dimethyl-1-pyrrolidinyloxyl (DMPO-OH) was observed during the metabolism of ADM by CTE cells. However, the addition of dimethyl sulfoxide to the in vitro system suggested that superoxide is initially spin trapped by the nitrone, and that the adduct 2-hydroperoxy-5,5-dimethyl-1-pyrrolidinyloxyl (DMPO-OOH) is rapidly bioreduced to afford DMPO-OH. The addition of superoxide dismutase to the system indicated that superoxide generation was primarily intracellular. The adriamycin semiquinone free radical (ADM-SQ) was produced during the metabolism by enterocytes and hepatocytes. The rate of the production of ADM-SQ was enhanced under anaerobic conditions, suggesting that molecular oxygen was responsible for the degradation of this carbon-centered free radical. However, spin trapping of oxygen radicals was not observed; this observation suggests that these reactive intermediates are not produced at concentrations sufficient for detection by spin-trapping experiments.