Myosin-5 varies its step length to carry cargo straight along the irregular F-actin track.

Molecular motors employ chemical energy to generate unidirectional mechanical output against a track while navigating a chaotic cellular environment, potential disorder on the track, and against Brownian motion. Nevertheless, decades of nanometer-precise optical studies suggest that myosin-5a, one of the prototypical molecular motors, takes uniform steps spanning 13 subunits (36 nm) along its F-actin track. Here, we use high-resolution interferometric scattering microscopy to reveal that myosin takes strides spanning 22 to 34 actin subunits, despite walking straight along the helical actin filament. We show that cumulative angular disorder in F-actin accounts for the observed proportion of each stride length, akin to crossing a river on variably spaced stepping stones. Electron microscopy revealed the structure of the stepping molecule. Our results indicate that both motor and track are soft materials that can adapt to function in complex cellular conditions.

Clinical and Histopathologic Spectrum of Toxic Erythema of Chemotherapy: A Series of 56 Cases From a Single Institution.

INTRODUCTION: Although many individual cases and small series of toxic erythema of chemotherapy (TEC) have been described, the full spectrum of findings is not well understood. OBJECTIVE: To provide a comprehensive review of the clinical and histopathologic features of TEC with an emphasis on novel histopathologic findings. METHODS: We searched our electronic medical record for "toxic erythema of chemotherapy" or "neutrophilic eccrine hidradenitis." Fifty-six cases meeting clinical and histopathologic criteria were identified. The electronic medical record and accompanying hematoxylin and eosin-stained slides were retrospectively reviewed. RESULTS: The clinical findings were heterogeneous but included classic presentations such as intertriginous eruptions (34%) and acral erythema (25%). The most common histopathologic features were apoptotic keratinocytes (95%), basal vacuolar change (91%), and epithelial dysmaturation (79%). Eccrine squamous syringometaplasia was seen in over half of the cases (33/56; 59%), whereas neutrophilic eccrine hidradenitis was uncommon (16%). Interestingly, many cases showed prominent interstitial histiocytes (55%). Other novel findings included irregular orthohyperkeratosis (23%), irregular epidermal hyperplasia (14%), and acantholysis (9%). LIMITATIONS: As a retrospective study, it is subject to information bias. CONCLUSION: This is the largest reported series of TEC. In addition to confirming previously reported features, we identify novel histopathologic findings to add to the spectrum of TEC.

Perioperative Brain Health in the Older Adult: A Patient Safety Imperative.

While people 65 years of age and older represent 16% of the population in the United States, they account for >40% of surgical procedures performed each year. Maintaining brain health after anesthesia and surgery is not only important to our patients, but it is also an increasingly important patient safety imperative for the specialty of anesthesiology. Aging is a complex process that diminishes the reserve of every organ system and often results in a patient who is vulnerable to the stress of surgery. The brain is no exception, and many older patients present with preoperative cognitive impairment that is undiagnosed. As we age, a number of changes occur in the human brain, resulting in a patient who is less resilient to perioperative stress, making older adults more susceptible to the phenotypic expression of perioperative neurocognitive disorders. This review summarizes the current scientific and clinical understanding of perioperative neurocognitive disorders and recommends patient-centered, age-focused interventions that can better mitigate risk, prevent harm, and improve outcomes for our patients. Finally, it discusses the emerging topic of sleep and cognitive health and other future frontiers of scientific inquiry that might inform clinical best practices.

Anesthesia Patient Safety: Next Steps to Improve Worldwide Perioperative Safety by 2030.

Patient safety is a core principle of anesthesia care worldwide. The specialty of anesthesiology has been a leader in medicine for the past half century in pursuing patient safety research and implementing standards of care and systematic improvements in processes of care. Together, these efforts have dramatically reduced patient harm associated with anesthesia. However, improved anesthesia patient safety has not been uniformly obtained worldwide. There are unique differences in patient safety outcomes between countries and regions in the world. These differences are often related to factors such as availability, support, and use of health care resources, trained personnel, patient safety outcome data collection efforts, standards of care, and cultures of safety and teamwork in health care facilities. This article provides insights from national anesthesia society leaders from 13 countries around the world. The countries they represent are diverse geographically and in health care resources. The authors share their countries' current and future initiatives in anesthesia patient safety. Ten major patient safety issues are common to these countries, with several of these focused on the importance of extending initiatives into the full perioperative as well as intraoperative environments. These issues may be used by anesthesia leaders around the globe to direct collaborative efforts to improve the safety of patients undergoing surgery and anesthesia in the coming decade.

Primary cutaneous malignant perivascular epithelioid cell tumor: Case of a rare tumor with review of the literature.

Perivascular epithelioid cell tumors (PEComas) are mesenchymal neoplasms with characteristic epithelioid or spindled cytomorphology that typically grow around blood vessels. These tumors are phenotypically and immunohistochemically distinct, expressing markers of both melanocytic and smooth muscle differentiation. Herein, we describe a case of histopathologically malignant cutaneous PEComa without metastatic spread, with review of the pertinent literature. Telescoping punch biopsy demonstrated an epithelioid neoplasm with marked atypia, hypercellularity, and increased mitotic activity. Immunohistochemical stains for HMB-45, NK1-C3, PGP9.5, MiTF, CD10, and CD68 were positive within tumor cells. In addition, there was diffuse expression of caldesmon and focal cytoplasmic staining for smooth muscle actin on the excision specimen. The patient underwent treatment with surgical excision with adjuvant radiation and surveillance computed tomography (CT). The patient remains free of recurrence or metastatic disease after 10 months of follow-up. To our knowledge, this is only the third reported case of a malignant cutaneous PEComa reported in the literature to date.

Anesthesiologists' Role in Value-based Perioperative Care and Healthcare Transformation.

Health care is undergoing major transformation with a shift from fee-for-service care to fee-for-value. The advent of new care delivery and payment models is serving as a driver for value-based care. Hospitals, payors, and patients increasingly expect physicians and healthcare systems to improve outcomes and manage costs. The impact of the coronavirus disease 2019 (COVID-19) pandemic on surgical and procedural practices further highlights the urgency and need for anesthesiologists to expand their roles in perioperative care, and to impact system improvement. While there have been substantial advances in anesthesia care, perioperative complications and mortality after surgery remain a key concern. Anesthesiologists are in a unique position to impact perioperative health care through their multitude of interactions and influences on various aspects of the perioperative domain, by using the surgical experience as the first touchpoint to reengage the patient in their own health care. Among the key interventions that are being effectively instituted by anesthesiologists include proactive engagement in preoperative optimization of patients' health; personalization and standardization of care delivery by segmenting patients based upon their complexity and risk; and implementation of best practices that are data-driven and evidence-based and provide structure that allow the patient to return to their optimal state of functional, cognitive, and psychologic health. Through collaborative relationships with other perioperative stakeholders, anesthesiologists can consolidate their role as clinical leaders driving value-based care and healthcare transformation in the best interests of patients.

Multiple Myeloma in Hispanics: Incidence, Characteristics, Survival, Results of Discovery, and Validation Using Real-World and Connect MM Registry Data.

BACKGROUND: Multiple myeloma (MM) in Hispanics has never been studied. We therefore sought to determine the clinical characteristics and overall survival in MM of Hispanics compared to non-Hispanic whites (NHW) and non-Hispanic blacks (NHB). PATIENTS AND METHODS: A single-center analysis of 939 patients diagnosed with MM from 2000 to 2017 with a large representation of NHB (n = 489), Hispanics (n = 281), and NHW (n = 169) was conducted to evaluate outcomes and disease characteristics. We used the Connect MM Registry, a large US multicenter prospective observational study with newly diagnosed MM patients, as a validation cohort. RESULTS: Hispanics had a higher incidence of MM compared to NHW. The median age at presentation was 5 years younger (median, 65 years) in Hispanics compared to NHW (median, 70 years), and patients were more likely to present with renal dysfunction (estimated glomerular filtration rate < 30 mL/min). Hispanics had a higher proportion of Revised International Staging System (R-ISS) stage I disease compared to NHW and NHB (P = .03), while there was no difference in cytogenetics between Hispanics and NHB/NHW. In the multivariate analysis, only high-risk disease and response to first-line therapy significantly affected survival. CONCLUSION: In this first and largest analysis of MM in Hispanics, we found that Hispanics present at a younger age, have a higher incidence of renal dysfunction, and have low R-ISS stage disease at presentation. With equal access to therapy, Hispanics have survival similar to NHW/NHB.

Post Prostatectomy Pathologic Findings of Patients With Clinically Significant Prostate Cancer and no Significant PI-RADS Lesions on Preoperative Magnetic Resonance Imaging.

OBJECTIVES: We present postprostatectomy pathology results from a series of prostate cancer (Pca) Gleason grade group ≥2 patients who did not have findings suggestive of cancer on preoperative pelvic magnetic resonance imaging (MRI). METHODS: We performed an institutional retrospective study of prostate magnetic resonance imaging (MRI) examinations done from October 2015 to February 2018. We identified patients who underwent prostatectomy for Pca Gleason ≥3 + 4 diagnosed on prostate biopsy with no associated MRI findings suggestive of malignancy and analyzed their postprostatectomy pathologic findings and MRI imaging results. RESULTS: At our institution, 850 men with Pca received MRI between 2015 and 2018, and 156/850 patients received robotic-assisted radical prostatectomy. Thirty-three patients (33/156 = 21%) had negative MRI for PIRAD 3 or greater but had a biopsy showing significant Pca. Their mean (range) age was 62.7 (50-86) years. Their median (interquartile range) PSA, and PSA density were, 4.6 (3.7) ng/mL and 0.12 (0.05) ng/mL/cm2, respectively; all not significantly different from patients with visible lesions on MRI who underwent surgery. On post prostatectomy pathology, 27/33 (82%) men had Pca Gleason score 7 or greater. The most common pattern was infiltrative growth with cancer glands intermingling between benign glands. CONCLUSION: We describe the pathologic and imaging findings in an extensive series of men with clinically significant Pca with no significant lesions on preoperative MRI. Our results support the importance of patient counseling on the risk of missing significant Pca on MRI in isolation from other clinical variables.

Case Fatality Rate of Cancer Patients with COVID-19 in a New York Hospital System.

Patients with cancer are presumed to be at increased risk from COVID-19 infection-related fatality due to underlying malignancy, treatment-related immunosuppression, or increased comorbidities. A total of 218 COVID-19-positive patients from March 18, 2020, to April 8, 2020, with a malignant diagnosis were identified. A total of 61 (28%) patients with cancer died from COVID-19 with a case fatality rate (CFR) of 37% (20/54) for hematologic malignancies and 25% (41/164) for solid malignancies. Six of 11 (55%) patients with lung cancer died from COVID-19 disease. Increased mortality was significantly associated with older age, multiple comorbidities, need for ICU support, and elevated levels of D-dimer, lactate dehydrogenase, and lactate in multivariate analysis. Age-adjusted CFRs in patients with cancer compared with noncancer patients at our institution and New York City reported a significant increase in case fatality for patients with cancer. These data suggest the need for proactive strategies to reduce likelihood of infection and improve early identification in this vulnerable patient population. SIGNIFICANCE: COVID-19 in patients with cancer is associated with a significantly increased risk of case fatality, suggesting the need for proactive strategies to reduce likelihood of infection and improve early identification in this vulnerable patient population.This article is highlighted in the In This Issue feature, p. 890.

Targeting the unfolded protein response in head and neck and oral cavity cancers.

Many FDA-approved anti-cancer therapies, targeted toward a wide array of molecular targets and signaling networks, have been demonstrated to activate the unfolded protein response (UPR). Despite a critical role for UPR signaling in the apoptotic execution of cancer cells by many of these compounds, the authors are currently unaware of any instance whereby a cancer drug was developed with the UPR as the intended target. With the essential role of the UPR as a driving force in the genesis and maintenance of the malignant phenotype, a great number of pre-clinical studies have surged into the medical literature describing the ability of dozens of compounds to induce UPR signaling in a myriad of cancer models. The focus of the current work is to review the literature and explore the role of the UPR as a mediator of chemotherapy-induced cell death in squamous cell carcinomas of the head and neck (HNSCC) and oral cavity (OCSCC), with an emphasis on preclinical studies.

Endocrine, Sexual Function, and Infertility Side Effects of Immune Checkpoint Inhibitor Therapy for Genitourinary Cancers.

PURPOSE OF REVIEW: Immune checkpoint therapy has grown in prominence in the last few decades and is being increasingly utilized in treatment of advanced cancers. Although information on toxicities of these drugs is forthcoming, not much is known regarding the toxicity profile of these drugs from a sexual function standpoint. We undertook the current review to appraise the literature for endocrine/sexual side effects of anti-PD-1/PD-L1 and anti-CTLA-4 therapy. RECENT FINDINGS: Our review included 32 articles and focused primarily on the programmed death (PD) pathway. We found that endocrine side effects after anti-PD-1/PD-L1 therapy are relatively rare, with hypothyroidism (range < 1 to 40%) and hypophysitis (range < 1 to 10%) being the two most common. None of the studies specifically commented on the infertility or sexual side effects of these drugs. However, two studies evaluating biochemical profiles of patients undergoing therapy with ipilimumab (a CTLA-4 inhibitor) or combination therapy (CTLA-4 + PD-1/PD-L1 inhibitors) noted that about < 1 to ~ 60% of the patients developed hypogonadotropic hypogonadism. None of the studies provided information regarding clinically meaningful sexual health endpoints such as libido, erectile function assessments, or sexual function-related quality of life. Endocrine side effects, although uncommon, are important and unique side effects of immune checkpoint therapy because they are often complex and can be life threatening. While side effects on sexual health may not be life threatening, they are lifestyle limiting. Thus, long-term follow-up, post-marketing surveillance, and future studies will need to elucidate the true rates of endocrine/sexual side effects and the mechanisms underlying them. This will aid in better counseling of the patients, as more of them undergo these novel immune checkpoint inhibitor therapies.

Acute scrotum in setting of acute pancreatitis.

Acute scrotum is a urologic emergency with many aetiologies. Acute scrotum in setting of acute pancreatitis is a rare occurrence and results from an effusion of pancreatic juices into the inguinal canal along a retroperitoneal tract. Knowledge regarding the existence of this obscure condition is essential for its diagnosis. It is thus important for medical professionals, particularly internists, surgical trainees and emergency physicians, to be aware of the condition and the options for its management.

Cardiovascular Complications of Proteasome Inhibitors Used in Multiple Myeloma.

The use of proteasome inhibitors (PI) as targeted chemotherapeutics have significantly improved survival in patients with multiple myeloma (MM). However, rare and serious cardiovascular complications have occurred as a result of their use, most commonly congestive heart failure, hypertension, and arrhythmias. MM occurs in an aged population with many concurrent cardiovascular risk factors. The primary disease process also contributes to cardiovascular complications. Furthermore, many MM patients have prior exposure to cardiotoxic chemotherapy such as anthracyclines. Because of these occurrences, the identification, prevention, and management of cardiovascular complications is made increasingly difficult. Various clinical studies and case reports have documented cardiotoxicity among all 3 of the currently approved PIs, bortezomib, carfilzomib, and ixazomib. Carfilzomib has shown the highest rates of cardiotoxicity, whereas there is conflicting evidence regarding bortezomib's role in producing cardiotoxicity. However, various case reports have documented the existence of adverse cardiac effects. Higher frequencies of complications have also been seen in "real-life" populations with cardiovascular co-morbidities who were originally excluded from clinical studies. Ixazomib, the most recently approved PI, has also been proposed to cause cardiotoxicity, elucidating a possible class effect. PIs are thought to cause cardiotoxicity through the unfolded protein response, leading to apoptosis in cardiac myocytes. Apremilast and rutin have been used in an animal model to reverse this signaling. Standardized guidelines identifying patients at greatest risk, to prevent and manage complications, have not yet been developed. Efforts have been made to prioritize patients older than 60 years with anthracycline exposure, cardiovascular risk factors, or amyloidosis. Withholding medication, using slower-infusion times, limiting fluids and providing supportive therapy have been successful. Screening echocardiograms have not been proven effective.

Loss of APOBEC1 RNA-editing function in microglia exacerbates age-related CNS pathophysiology.

Microglia (MG), a heterogeneous population of phagocytic cells, play important roles in central nervous system (CNS) homeostasis and neural plasticity. Under steady-state conditions, MG maintain homeostasis by producing antiinflammatory cytokines and neurotrophic factors, support myelin production, and remove synapses and cellular debris, as well as participating in "cross-correction," a process that supplies neurons with key factors for executing autophagy-lysosomal function. As sentinels for the immune system, MG also detect "danger" signals (pathogenic or traumatic insult), become activated, produce proinflammatory cytokines, and recruit monocytes and dendritic cells to the site of damage through a breached blood-brain barrier or via brain lymphatics. Failure to effectively resolve MG activation can be problematic and can lead to chronic inflammation, a condition proposed to underlie CNS pathophysiology in heritable brain disorders and age-related neurodegenerative and cognitive decline. Here, we show that APOBEC1-mediated RNA editing occurs within MG and is key to maintaining their resting status. Like bone marrow-derived macrophages, RNA editing in MG leads to overall changes in the abundance of edited proteins that coordinate the function of multiple cellular pathways. Conversely, mice lacking the APOBEC1 editing function in MG display evidence of dysregulation, with progressive age-related signs of neurodegeneration, characterized by clustering of activated MG, aberrant myelination, increased inflammation, and lysosomal anomalies that culminate in behavioral and motor deficiencies. Collectively, our study identifies posttranscriptional modification by RNA editing as a critical regulatory mechanism of vital cellular functions that maintain overall brain health.

Computationally-guided optimization of small-molecule inhibitors of the Aurora A kinase-TPX2 protein-protein interaction.

Free energy perturbation theory, in combination with enhanced sampling of protein-ligand binding modes, is evaluated in the context of fragment-based drug design, and used to design two new small-molecule inhibitors of the Aurora A kinase-TPX2 protein-protein interaction.

In situ Synthesis of Fluorescent Gold Nanoclusters by Nontumorigenic Microglial Cells.

To date, the directed in situ synthesis of fluorescent gold nanoclusters (AuNCs) has only been demonstrated in cancerous cells, with the theorized synthesis mechanism prohibiting AuNC formation in nontumorigenic cell lines. This limitation hinders potential biostabilized AuNC-based technology in healthy cells involving both chemical and mechanical analysis, such as the direct sensing of protein function and the elucidation of local mechanical environments. Thus, new synthesis strategies are required to expand the application space of AuNCs beyond cancer-focused cellular studies. In this contribution, we have developed the methodology and demonstrated the direct in situ synthesis of AuNCs in the nontumorigenic neuronal microglial line, C8B4. The as-synthesized AuNCs form in situ and are stabilized by cellular proteins. The clusters exhibit bright green fluorescence and demonstrate low (<10%) toxicity. Interestingly, elevated ROS levels were not required for the in situ formation of AuNCs, although intracellular reductants such as glutamate were required for the synthesis of AuNCs in C8B4 cells. To our knowledge, this is the first-ever demonstration of AuNC synthesis in nontumorigenic cells and, as such, it considerably expands the application space of biostabilized fluorescent AuNCs.