Year in Review 2022: Noteworthy Literature in Cardiac Anesthesiology.

Last year researchers made substantial progress in work relevant to the practice of cardiac anesthesiology. We reviewed 389 articles published in 2022 focused on topics related to clinical practice to identify 16 that will impact the current and future practice of cardiac anesthesiology. We identified 4 broad themes including risk prediction, postoperative outcomes, clinical practice, and technological advances. These articles are representative of the best work in our field in 2022.

Airway and Hemodynamic Considerations for the Anesthetic Management of an Intraluminal Tracheal Plasmacytoma.

Central airway obstruction due to tracheal tumors presents unique challenges to the anesthesiologist. We present the case of a 44-year-old male taken to the OR for biopsy and resection of an undiagnosed tracheal mass. Intraoperative management was complicated by bleeding and significant hemodynamic instability, necessitating rapid surgical and anesthetic intervention. This ultimately led to abortion of surgical resection. Pathologic examination revealed a primary tracheal plasmacytoma, a rare type of tracheal tumor. Here, we describe anesthetic and hemodynamic considerations for a tracheal plasmacytoma. We discuss the approach to airway management in variable intrathoracic tracheal obstruction and the unpredictability of tracheal tumors.

Year in Review 2021: Noteworthy Literature in Cardiothoracic Anesthesia.

In 2021, progress in clinical science related to Cardiac Anesthesiology continued, but at a slower rate due to the ongoing pandemic and disruptions to clinical research. Most progress was incremental and addressed persistent questions related to our field. To identify articles for this review, we completed a structured review using our previously reported methods (1). Specifically, we used the search terms: "cardiac anesthesiology and outcomes" (n = 177), "cardiothoracic anesthesiology" (n = 34), "cardiac anesthesia," and "clinical outcomes" (n = 42) filtered on clinical trials and the year 2021 in PubMed. We also reviewed clinical trials from the most prominent clinical journals to identify additional studies for a narrative review. We then selected the most noteworthy publications for inclusion in this review and identified key themes.

Tailoring Heterogeneous Catalysts at the Atomic Level: In Memoriam, Prof. Chia-Kuang (Frank) Tsung.

Professor Chia-Kuang (Frank) Tsung made his scientific impact primarily through the atomic-level design of nanoscale materials for application in heterogeneous catalysis. He approached this challenge from two directions: above and below the material surface. Below the surface, Prof. Tsung synthesized finely controlled nanoparticles, primarily of noble metals and metal oxides, tailoring their composition and surface structure for efficient catalysis. Above the surface, he was among the first to leverage the tunability and stability of metal-organic frameworks (MOFs) to improve heterogeneous, molecular, and biocatalysts. This article, written by his former students, seeks first to commemorate Prof. Tsung's scientific accomplishments in three parts: (1) rationally designing nanocrystal surfaces to promote catalytic activity; (2) encapsulating nanocrystals in MOFs to improve catalyst selectivity; and (3) tuning the host-guest interaction between MOFs and guest molecules to inhibit catalyst degradation. The subsequent discussion focuses on building on the foundation laid by Prof. Tsung and on his considerable influence on his former group members and collaborators, both inside and outside of the lab.

Year in Review 2020: Noteworthy Literature in Cardiothoracic Anesthesiology.

The year 2020 was marred by the emergence of a deadly pandemic that disrupted every aspect of life. Despite the disruption, notable research accomplishments in the practice of cardiothoracic anesthesiology occurred in 2020 with an emphasis on optimizing care, improving outcomes, and expanding what is possible for patients undergoing cardiac surgery. This year's edition of Noteworthy Literature Review will focus on specific themes in cardiac anesthesiology that include preoperative anemia, predictors of acute kidney injury following cardiac surgery, pain management modalities, anticoagulation strategies after transcatheter aortic valve replacement, mechanical circulatory support, and future directions in research.

Noteworthy Literature in Cardiac Anesthesia for 2019.

This article represents a selective review of literature published in 2019. Initial results from PubMed searching for a combination of terms, including cardiac anesthesiology and anesthesiology outcomes, yielded more than 1400 publications. From there, we manually screened the results and identified 5 major themes for the year of 2019, including transcatheter techniques, delirium and anesthesiology, coagulation management following cardiopulmonary bypass, perfusion management with del Nido cardioplegia, and applied clinical research. The following research accomplishments have expanded what is possible and set ambitious goals for the future.

Current Neurologic Assessment and Neuroprotective Strategies in Cardiac Anesthesia: A Survey to the Membership of the Society of Cardiovascular Anesthesiologists.

BACKGROUND: Neurologic injury and cognitive disorder after cardiac surgery are associated with morbidity and mortality. Variability in the application of neuroprotective strategies likely exists during cardiac surgery. The Society of Cardiovascular Anesthesiologists (SCA) conducted a survey among its members on common perioperative neuroprotective strategies: assessment of aortic atheromatous burden, management of intraoperative blood pressure, and use of cerebral oximetry. METHODS: A 15-item survey was developed by 3 members of the SCA Continuous Practice Improvement - Cerebral Protection Working Group. The questionnaire was then circulated among all working group members, adapted, and tested for face validity. On March 26, 2018, the survey was sent to members of the SCA via e-mail using the Research Electronic Data Capture system. Responses were recorded until April 16, 2018. RESULTS: Of the 3645 surveys e-mailed, 526 members responded (14.4%). Most responders worked in academic institutions (58.3%), followed by private practices (38.7%). Epiaortic ultrasound for the assessment of aortic atheromatous burden was most commonly utilized at the surgeon's request (46.5%). Cerebral oximetry was most commonly used in patients with increased perioperative risk of cerebral injury (41.4%). Epiaortic ultrasound (1.9%) and cerebral oximetry (5.2%) were rarely part of a standardized monitoring approach. A majority of respondents (52.0%) reported no standardized management strategies for neuroprotection during cardiac surgery at their institution. A total of 55.3% stated that no standardized institutional guidelines were in place for managing a patient's blood pressure intraoperatively or during cardiopulmonary bypass. When asked about patients at risk for postoperative cerebral injury, 41.3% targeted a blood pressure goal >65 mmHg during cardiopulmonary bypass. The majority of responders (60.4%) who had access to institutional rates of postoperative stroke/cerebral injury had standard neuroprotective strategies in place. CONCLUSIONS: Our data indicate that approximately half of the respondents to this SCA survey do not use standardized guidelines/standard operating procedures for perioperative cerebral protection. The lack of standardized neuroprotective strategies during cardiac surgery may impact postoperative neurologic outcomes. Further investigations are warranted and should assess the association of standardized neuroprotective approaches and postoperative neurological outcomes.

Driving CO2 to a Quasi-Condensed Phase at the Interface between a Nanoparticle Surface and a Metal-Organic Framework at 1 bar and 298 K.

We demonstrate a molecular-level observation of driving CO2 molecules into a quasi-condensed phase on the solid surface of metal nanoparticles (NP) under ambient conditions of 1 bar and 298 K. This is achieved via a CO2 accumulation in the interface between a metal-organic framework (MOF) and a metal NP surface formed by coating NPs with a MOF. Using real-time surface-enhanced Raman scattering spectroscopy, a >18-fold enhancement of surface coverage of CO2 is observed at the interface. The high surface concentration leads CO2 molecules to be in close proximity with the probe molecules on the metal surface (4-methylbenzenethiol), and transforms CO2 molecules into a bent conformation without the formation of chemical bonds. Such linear-to-bent transition of CO2 is unprecedented at ambient conditions in the absence of chemical bond formation, and is commonly observed only in pressurized systems (>105 bar). The molecular-level observation of a quasi-condensed phase induced by MOF coating could impact the future design of hybrid materials in diverse applications, including catalytic CO2 conversion and ambient solid-gas operation.

Shielding against Unfolding by Embedding Enzymes in Metal-Organic Frameworks via a de Novo Approach.

We show that an enzyme maintains its biological function under a wider range of conditions after being embedded in metal-organic framework (MOF) microcrystals via a de novo approach. This enhanced stability arises from confinement of the enzyme molecules in the mesoporous cavities in the MOFs, which reduces the structural mobility of enzyme molecules. We embedded catalase (CAT) into zeolitic imidazolate frameworks (ZIF-90 and ZIF-8), and then exposed both embedded CAT and free CAT to a denature reagent (i.e., urea) and high temperatures (i.e., 80 °C). The embedded CAT maintains its biological function in the decomposition of hydrogen peroxide even when exposed to 6 M urea and 80 °C, with apparent rate constants kobs (s-1) of 1.30 × 10-3 and 1.05 × 10-3, respectively, while free CAT shows undetectable activity. A fluorescence spectroscopy study shows that the structural conformation of the embedded CAT changes less under these denaturing conditions than free CAT.

Pneumomediastinum and Bilateral Pneumothoraces Causing Respiratory Failure after Thyroid Surgery.

We report the first case of severe respiratory failure after thyroid surgery requiring venovenous extracorporeal membrane oxygenation (vvECMO). The patient was a 41-year-old woman with metastatic thyroid cancer. She underwent thyroidectomy, including left lateral and bilateral central neck dissection. During surgery, the patient developed pneumomediastinum with bilateral pneumothoraces. Despite early treatment with bilateral chest tubes and no evidence of a tracheal perforation, the patient developed severe respiratory failure after extubation on the intensive care unit. Because pneumothorax and pneumomediastinum might be more common than reported, and considering increasing cases of thyroid surgery, staff should remain vigilant of pulmonary complications after thyroid surgery.

Formation of hollow and mesoporous structures in single-crystalline microcrystals of metal-organic frameworks via double-solvent mediated overgrowth.

The creation of hierarchical porosity in metal-organic frameworks (MOFs) could benefit various applications of MOFs such as gas storage and separation. Having single-crystalline microcrystals instead of poly-crystalline composites is critical for these potential applications of MOFs with hierarchical porosity. We developed a room temperature synthetic method to generate uniform hollow and mesoporous zeolitic imidazolate framework-8 (ZIF-8) microcrystals with a single-crystalline structure via overgrowing a ZIF-8 shell in methanol solution on a ZIF-8 core with water adsorbed in the pores. The cavities formed as a result of the different solvent micro-environment. This double-solvent mediated overgrowth method could be applied to prepare other MOFs with hierarchical porosity.

Imparting functionality to biocatalysts via embedding enzymes into nanoporous materials by a de novo approach: size-selective sheltering of catalase in metal-organic framework microcrystals.

We develop a new concept to impart new functions to biocatalysts by combining enzymes and metal-organic frameworks (MOFs). The proof-of-concept design is demonstrated by embedding catalase molecules into uniformly sized ZIF-90 crystals via a de novo approach. We have carried out electron microscopy, X-ray diffraction, nitrogen sorption, electrophoresis, thermogravimetric analysis, and confocal microscopy to confirm that the ~10 nm catalase molecules are embedded in 2 µm single-crystalline ZIF-90 crystals with ~5 wt % loading. Because catalase is immobilized and sheltered by the ZIF-90 crystals, the composites show activity in hydrogen peroxide degradation even in the presence of protease proteinase K.

Molecular encapsulation beyond the aperture size limit through dissociative linker exchange in metal-organic framework crystals.

Under linker exchange conditions, large guests with molecular diameters 3-4 times the framework aperture size have been encapsulated into preformed nanocrystals of the metal-organic framework ZIF-8. Guest encapsulation is facilitated by the formation of short-lived "open" states of the pores upon linker dissociation. Kinetic studies suggested that linker exchange reactions in ZIF-8 proceed via a competition between dissociative and associative exchange mechanisms, and guest encapsulation was enhanced under conditions where the dissociative pathway predominates.

Tissue-specific regulation of porcine prolactin receptor expression by estrogen, progesterone, and prolactin.

Prolactin (PRL) acts through its receptor (PRLR) via both endocrine and local paracrine/autocrine pathways to regulate biological processes including reproduction and lactation. We analyzed the tissue- and stage of gestation-specific regulation of PRL and PRLR expression in various tissues of pigs. Abundance of pPRLR-long form (LF) mRNA increased in the mammary gland and endometrium during gestation while in other tissues it remained constant. There was a parallel increase in the abundance of the pPRLR-LF protein in the mammary gland and endometrium during gestation. We determined the hormonal regulation of pPRLR-LF mRNA expression in various tissues from ovariectomized, hypoprolactinemic gilts given combinations of the replacement hormones estrogen (E(2)), progestin (P), and/or haloperidol-induced PRL. Abundance of pPRLR-LF mRNA in kidney and liver was unaffected by hormone treatments. Expression of uterine pPRLR-LF mRNA was induced by E(2) whereas the effect of E(2) was abolished by co-administering P. The expression of pPRLR-LF mRNA in the mammary gland stroma was induced by PRL, whereas E(2) induced its expression in the epithelium. In contrast to these changes in pPRLR expression, pPRL expression was relatively constant and low during gestation in all tissues except the pituitary. Taken together, these data reveal that specific combinations of E(2), P, and PRL differentially regulate pPRLR-LF expression in the endometrium and mammary glands, and that the action of PRL on its target tissues is dependent upon pPRLR-LF abundance more so than the local PRL expression.

A 5' distal palindrome within the mouse mammary tumor virus-long terminal repeat recruits a mammary gland-specific complex and is required for a synergistic response to progesterone plus prolactin.

Progesterone (P) and prolactin (PRL) fulfill crucial roles during growth and differentiation of the mammary epithelium, and each has been implicated in the pathogenesis of mammary cancer. We previously identified that these hormones synergistically stimulate the proliferation of mouse mammary epithelial cells in vivo, although the mechanism(s) underlying their cooperative effect are unknown. We now report a novel pathway by which P and PRL synergize to activate transcription from the long terminal repeat (LTR) of the mouse mammary tumor virus-LTR (MMTV-LTR) in T47D breast cancer cells. Using serial 5' and 3' deletions of the MMTV-LTR, in addition to selective mutations, we identified that a previously uncharacterized inverted palindrome on the distal enhancer (-941/-930), in addition to a signal transducer and activator of transcription 5 site, was essential for the synergistic activation of transcription by P and PRL. Notably, hormone synergy occurred via a mechanism that was independent of the P receptor DNA-binding elements found in the proximal MMTV-LTR hormone-response element. The palindrome specifically recruited a protein complex (herein termed mammary gland-specific complex) that was almost exclusive to normal and cancerous mammary cells. The synergy between P and PRL occurred via a Janus kinase 2 and c-Src/Fyn-dependent signaling cascade downstream of P and PRL receptors. Combined, our data outline a novel pathway in T47D cells that may facilitate the action(s) of P and PRL during mammary development and breast cancer.