Orbital Crossings Activated through Electron Injection: Opening Communication between Orthogonal Orbitals in Anionic C1-C5 Cyclizations of Enediynes.

Generally, the long-range electronic communication between spatially orthogonal orbitals is inefficient and limited to field and inductive effects. In this work, we provide experimental evidence that such communication can be achieved via intramolecular electron transfer between two degenerate and mutually orthogonal frontier molecular orbitals (MOs) at the transition state. Interaction between orthogonal orbitals is amplified when the energy gap between these orbitals approaches zero, or at an "orbital crossing". The crossing between two empty or two fully occupied MOs, which do not lead to stabilization, can be "activated" when one of the empty MOs is populated (i.e., electron injection) or one of the filled MOs is depopulated (i.e., hole injection). In reductive cycloaromatization reactions, such crossings define transition states with energies defined by both the in-plane and out-of-plane π-systems. Herein, we provide experimental evidence for the utility of this concept using orbital crossings in reductive C1-C5 cycloaromatization reactions of enediynes. Communication with remote substituents via orbital crossings greatly enhances regioselectivity of the ring closure step in comparison to the analogous radical cyclizations. We also present photophysical data pertaining to the efficiency of electron injection into the benzannelated enediynes.

Impact of genotype on clinical course in sickle cell disease and the utility of neutrophil-lymphocyte ratio: a ten-year single-institution experience.

BACKGROUND: Sickle cell disease (SCD) is a diverse group of blood disorders with significant global disease burden. Contemporary interest in the underlying inflammatory paradigm of SCD has emphasized the role of the neutrophil-lymphocyte ratio (NLR) as a prognostic inflammatory marker. METHODS: We retrospectively reviewed 268 hospitalized patients with SCDs of different genotypes (HbSS, HbSß0 thalassemia, HbSß+ thalassemia, and HbSC), totaling 3329 hospital admissions over a 10-year period. Patients were stratified into SS/Sß0 and Sß+/SC groups for statistical analysis of parameters collected at steady state and at hospital admission. RESULTS: At steady state, per unit increase of hemoglobin values was associated with reduced odds of ≥ 2 hospital admissions per year in SS/Sß0 and Sß+/SC groups; per unit increase in platelet count and white blood cell count was associated with increased odds only in the SS/Sß0 group. The NLR had no association in either group. During admission, a cutoff of NLR = 3.5 discerned infection with a sensitivity of 60% and specificity of 57%. Performance improved when excluding patients on outpatient hydroxyurea therapy (cutoff of NLR = 3.5; sensitivity of 68% and specificity of 64%). CONCLUSION: This study supports the utility of NLR as an accessible adjunctive clinical tool in SCD prognostication.

Forming the Hematology-Oncology Collaborative Videoconferencing (CO-VID) Learning Initiative: Experiential Lessons Learned From a Novel Trainee-Led Multidisciplinary Virtual Learning Platform.

PURPOSE: COVID-19 challenged medical practice and graduate medical education. Building on previous initiatives, we describe and reflect on the formative process and goals of the Hematology-Oncology Collaborative Videoconferencing Learning Initiative, a trainee-led multi-institutional virtual COVID-19 learning model. METHODS: Clinical fellows and faculty from 13 US training institutions developed consensus needs, goals, and objectives, recruited presenters, and generated a multidisciplinary COVID-19 curriculum. Weekly Zoom conferences consisted of two trainee-led instructional segments and a trainee-moderated faculty Q&A panel. Hematology-oncology training program faculty and trainees were the targeted audience. Leadership evaluations consisted of anonymized baseline and concluding mixed methods surveys. Presenter evaluations consisted of session debriefs and two structured focus groups. Conference evaluations consisted of attendance, demographics, and pre- or postmultiple-choice questions on topic learning objectives. RESULTS: In 6 weeks, the initiative produced five conferences: antivirals, anticoagulation, pulmonology, provider resilience, and resource scarcity ethics. The average attendance was 100 (range 57-185). Among attendees providing both pre- and postconference data, group-level knowledge appeared to increase: antiviral (n = 46) pre-/postcorrect 82.6%/97.8% and incorrect 10.9%/2.2%, anticoagulation (n = 60) pre-/postcorrect 75%/93.3% and incorrect 15%/6.7%, and pulmonary (n = 21) pre-/postcorrect 66.7%/95.2% and incorrect 33.3%/4.8%. Although pulmonary management comfort appeared to increase, comfort managing of antivirals and anticoagulation was unchanged. At the conclusion of the pilot, leadership trainees reported improved self-confidence organizing multi-institutional collaborations, median (interquartile range) 58.5 (50-64) compared with baseline 34 (26-39), but did not report improved confidence in other educational or leadership skills. CONCLUSION: During crisis, trainees built a multi-institutional virtual education platform for the purposes of sharing pandemic experiences and knowledge. Accomplishment of initiative goals was mixed. Lessons learned from the process and goals may improve future disaster educational initiatives.

Acquired von Willebrand syndrome in association with multiple myeloma: remission after stem cell transplant.

Acquired von Willebrand syndrome is a rare bleeding disorder characterised by a later age of onset without a personal or family history of bleeding diathesis. It is vital to discern acquired von Willebrand syndrome from inherited von Willebrand disease and other acquired bleeding disorders as management differs significantly. Acquired von Willebrand syndrome is usually secondary to an underlying disorder such as lymphoproliferative disorder, myeloproliferative neoplasm, solid tumour, cardiovascular disorder, autoimmune disorders or hypothyroidism. Diagnosis is often delayed with a significant risk of morbidity and even mortality. Here we present a case of a 74-year-old man with an acquired bleeding disorder and work up suggestive of acquired von Willebrand syndrome secondary to immunoglobulin G kappa multiple myeloma. He was treated successfully with intravenous immunoglobulin, von Willebrand Factor/Coagulation Factor VIII Complex (human), myeloma directed chemotherapy and autologous stem cell transplantation. We also discuss the management strategies that are largely based on retrospective studies and case reports.

Syncope caused by lymphomatous encasement of the internal carotid artery.

We present a case of a 77-year-old man who reported 5 months of syncopal episodes. He was found to have diffuse large B-cell lymphoma encasing the left internal carotid artery but not impeding blood flow. The syncopal episodes resolved after his first cycle of chemotherapy. Recurrent syncope in non-cardiac lymphomas and other head and neck masses is exceedingly rare and may be due to reflex syncope prompted by carotid baroreceptor activation. There are 11 previously described cases of recurrent syncope associated with non-cardiac lymphoma. In all cases, lymphadenopathy abutting the carotid artery was present and the syncopal episodes resolved with treatment. Our case illustrates that malignancy should be considered in patients with unexplained recurrent syncope.

Rapid onset vancomycin-induced thrombocytopenia confirmed by vancomycin antibody test.

We report a case of vancomycin-induced thrombocytopenia (VIT) with rapid onset after re-exposure to vancomycin. A 58-year-old man with cellulitis was initiated on vancomycin. Approximately 1 hour into the vancomycin infusion, the patient developed an infusion-related reaction. Vancomycin infusion was stopped. A complete blood count obtained 4 hours after discontinuation of the vancomycin infusion revealed a platelet count of 31 ×10-9/L. Investigations ruled out likely causes of thrombocytopenia. VIT was diagnosed based on clinical symptoms and confirmed with drug-dependent platelet antibody testing. Without complications, platelet counts recovered within 7 days after discontinuation of vancomycin. No correlation between vancomycin level and VIT was observed.

A Case of Plasmablastic Lymphoma Achieving Complete Response and Durable Remission after Lenalidomide-Based Therapy.

BACKGROUND: Plasmablastic lymphoma (PBL) is an uncommon variant of diffuse large B-cell lymphoma that is characterized by its plasmacytoid features, aggressive tendencies, and frequent association with human immunodeficiency virus (HIV) infection or other immunocompromised states. Multi-agent, intensive chemotherapy regimens are recommended as first-line treatment by the National Comprehensive Cancer Network. However, the toxicity of these regimens is high and prognosis remains poor. CASE REPORT: We report a patient with HIV-negative PBL who achieved complete response and durable remission using a lenalidomide-based chemotherapy regimen as first-line therapy. CONCLUSION: Cyclophosphamide, lenalidomide, dexamethasone (CRD) may provide an alternative initial therapeutic option for patients with PBL who cannot tolerate the intensive chemotherapy regimens currently recommended.

Suspected autoimmune myocarditis and cardiac conduction abnormalities with nivolumab therapy for non-small cell lung cancer.

Checkpoint inhibitors such as nivolumab represent a novel class of agents that are being increasingly used in the treatment of various cancers. Their toxicities represent unique challenges to the oncologists prescribing them, patients' primary care physicians and other specialists who may encounter these patients during consultations. It is important for physicians to remain vigilant and include autoimmune toxicities in the list of potential differential diagnoses in patients receiving novel cancer therapeutics who present with unusual toxicities. We report the unusual case of a 68-year-old woman with advanced lung cancer on the novel chemotherapeutic Nivolumab whom we suspect developed autoimmune myocarditis with significant cardiac conduction disease as an unintended, and as of yet unrecognised, side effect from this medication.