Nuclear F-actin assembly on damaged chromatin is regulated by DYRK1A and Spir1 phosphorylation.

Nuclear actin-based movements support DNA double-strand break (DSB) repair. However, molecular determinants that promote filamentous actin (F-actin) formation on the damaged chromatin remain undefined. Here we describe the DYRK1A kinase as a nuclear activity that promotes local F-actin assembly to support DSB mobility and repair, accomplished in part by its targeting of actin nucleator spire homolog 1 (Spir1). Indeed, perturbing DYRK1A-dependent phosphorylation of S482 mis-regulated Spir1 accumulation at damaged-modified chromatin, and led to compromised DSB-associated actin polymerization and attenuated DNA repair. Our findings uncover a role of the DYRK1A-Spir1 axis in nuclear actin dynamics during early DSB responses, and highlight the intricate details of nuclear cytoskeletal network in DSB repair and genome stability maintenance.

Peri-mortem rigidity in a fatal case of severe salicylate poisoning.

INTRODUCTION: There has been a previous case report of peri-arrest muscle rigidity in the setting of severe salicylate poisoning (serum salicylate concentration 1,500 mg/L), described as paratonia or rapid rigor mortis. We present an image of rapid rigor mortis in another fatal salicylate poisoning. CASE SUMMARY: We report a 42-year-old male with severe salicylate poisoning (peak salicylate concentration 1,600 mg/L). During the peri-arrest period, the patient developed isotonic flexion of the upper and lower extremities, the clinical signs of rapid-occurring rigor mortis. Despite resuscitative efforts, the patient died. IMAGE: Our patient is exhibiting peri-arrest rigidity in the upper extremities. DISCUSSION: Peri-mortem rigidity is due to depletion of adenosine triphosphate. Severe salicylate poisoning causes uncoupling of oxidative phosphorylation which prevents the production of adenosine triphosphate, which is required to release myosin from actin to allow the muscle to relax. A limitation of our report is that we did not definitively exclude other uncouplers of oxidative phosphorylation, such as 2,4-dinitrophenol. However, the history of aspirin ingestion was provided by the patient and corroborated by his mother, and it was confirmed by measurement of his salicylate concentration. CONCLUSION: We hypothesize that in our patient, rapid-occurring rigor mortis likely resulted from depletion of adenosine triphosphate. This occurred as a result of uncoupling of oxidative phosphorylation in the mitochondria from severe salicylate poisoning, as adenosine triphosphate is required for muscle relaxation.

Autophosphorylation of the Tousled-like kinases TLK1 and TLK2 regulates recruitment to damaged chromatin via PCNA interaction.

Tousled-like kinases 1 and 2 (TLK1 and 2) are cell cycle-regulated serine/threonine kinases that are involved in multiple biological processes. Mutation of TLK1 and 2 confer neurodegenerative diseases. Recent studies demonstrate that TLK1 and 2 are involved in DNA repair. However, there is no direct evidence that TLK1 and 2 function at DNA damage sites. Here, we show that both TLK1 and TLK2 are hyper-autophosphorylated at their N-termini, at least in part, mediated by their homo- or hetero-dimerization. We found that TLK1 and 2 hyper-autophosphorylation suppresses their recruitment to damaged chromatin. Furthermore, both TLK1 and 2 associate with PCNA specifically through their evolutionarily conserved non-canonical PCNA-interacting protein (PIP) box at the N-terminus, and mutation of the PIP-box abolishes their recruitment to DNA damage sites. Mechanistically, the TLK1 and 2 hyper-autophosphorylation masks the PIP-box and negatively regulates their recruitment to the DNA damage site. Overall, our study dissects the detailed genetic regulation of TLK1 and 2 at damaged chromatin, which provides important insights into their emerging roles in DNA repair.

The Clinical Toxicology Recommendations Collaborative: purpose, organization, and methodology.

INTRODUCTION: Scientific societies aim to provide a collective voice and unified stance on important issues. The Clinical Toxicology Recommendations Collaborative was formed in 2016 to develop evidence- and consensus-based recommendations for the management of patients exposed to common and/or serious poisonings for which the management is unclear or controversial. ORGANIZATION: The Clinical Toxicology Recommendations Collaborative is led jointly by the American Academy of Clinical Toxicology, the Asia Pacific Association of Medical Toxicology, and the European Association of Poison Centres and Clinical Toxicologists. The Governance Committee is chaired by a Past-President of one of these Societies and comprised of the six Presidents and Immediate Past-Presidents of the three Societies. A Steering Committee oversees the process of each project workgroup. METHODOLOGY: The overall process is guided by standards set forth by the Institute of Medicine for developing trustworthy guidelines and the Appraisal of Guidelines for Research and Evaluation Instrument. Systematic reviews are produced using the framework set in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. Workgroup members jointly review the evidence and prepare statements on which they vote anonymously using a 9-point Likert scale. A two-round modified Delphi method is used to reach a consensus on clinical recommendations using the RAND/UCLA Appropriateness Method. Final recommendations are approved by unanimous consent of the workgroup and are expressed as both levels of evidence and strength of recommendations. LIMITATIONS: The major limitations of the Clinical Toxicology Recommendations Collaborative process centre around the amount and quality of evidence, the assessment of that evidence, and the voting of the panel. CONCLUSIONS: By using a transparent evidence- and consensus-based approach to produce systematic reviews and clinical recommendations, the Clinical Toxicology Recommendations Collaborative aims to create an international framework for clinical toxicology education and decision-making and foster positive change for the benefit of poisoned patients.

Rare SNP in the HELB gene interferes with RPA interaction and cellular function of HELB.

HELB is a human helicase involved in initiation of DNA replication, the replication stress response, and regulation of double-strand DNA break repair. rs75770066 is a rare SNP in the HELB gene that affects age at natural menopause. rs75770066 results in a D506G substitution in an acidic patch within the 1A domain of the helicase that is known to interact with RPA. We found that this amino acid change dramatically impairs the cellular function of HELB. D506G-HELB exhibits impaired interaction with RPA, which likely results in the effects of rs75770066 as this reduces recruitment of HELB to sites of DNA damage. Reduced recruitment of D506G-HELB to double-strand DNA breaks and the concomitant increase in homologous recombination likely alters the levels of meiotic recombination, which affects the viability of gametes. Because menopause occurs when oocyte levels drop below a minimum threshold, altered repair of meiotic double-stranded DNA breaks has the potential to directly affect the age at natural menopause.

The exocyst complex is required for the trafficking and delivery of KCa3.1 to the basolateral membrane of polarized epithelia.

Control of the movement of ions and water across epithelia is essential for homeostasis. Changing the number or activity of ion channels at the plasma membrane is a significant regulator of epithelial transport. In polarized epithelia, the intermediate-conductance calcium-activated potassium channel, KCa3.1 is delivered to the basolateral membrane where it generates and maintains the electrochemical gradients required for epithelial transport. The mechanisms that control the delivery of KCa3.1 to the basolateral membrane are still emerging. Herein, we investigated the role of the highly conserved tethering complex exocyst. In epithelia, exocyst is involved in the tethering of post-Golgi secretory vesicles with the basolateral membrane, which is required before membrane fusion. In our Fisher rat thyroid cell line that stably expresses KCa3.1, siRNA knockdown of either of the exocyst subunits Sec3, Sec6, or Sec8 significantly decreased KCa3.1-specific current. In addition, knockdown of exocyst complex subunits significantly reduced the basolateral membrane protein level of KCa3.1. Finally, co-immunoprecipitation experiments suggest associations between Sec6 and KCa3.1, but not between Sec8 and KCa3.1. Collectively, based on these data and our previous studies, we suggest that components of exocyst complex are crucially important in the tethering of KCa3.1 to the basolateral membrane. After which, Soluble N-ethylmaleimide-sensitive factor (SNF) Attachment Receptors (SNARE) proteins aid in the insertion of KCa3.1-containing vesicles into the basolateral membrane of polarized epithelia.NEW & NOTEWORTHY Our Ussing chamber and immunoblot experiments demonstrate that when subunits of the exocyst complex were transiently knocked down, this significantly reduced the basolateral population and functional expression of KCa3.1. These data suggest, combined with our protein association experiments, that the exocyst complex regulates the tethering of KCa3.1-containing vesicles to the basolateral membrane prior to the SNARE-dependent insertion of channels into the basolateral membrane of epithelial cells.

Rapid induction onto extended-release injectable buprenorphine following opioid overdose: A case series.

Background: Buprenorphine treatment has been associated with reduced non-prescribed opioid use and opioid related overdose (OD). We evaluated initial outcomes of rapid induction onto extended-release injectable buprenorphine (BUP-XR) within 7 days of emergency department presentation for unintentional OD. Methods: Between February 2019-February 2021, N = 19 patients with opioid use disorder received buprenorphine/naloxone (4/1 mg), followed by BUP-XR (300 mg) at induction and continued BUP-XR outpatient for 6 months. Primary outcomes included adverse events, repeat OD, and death. Results: For patients who received at least one dose of BUP-XR, there were no treatment related serious adverse events or symptoms of precipitated withdrawal. In addition, there were no repeat visits for ODs or deaths within 6 months of the initial OD. Discussion: These preliminary findings support the need for larger controlled clinical trials to examine the safety and efficacy of rapid induction of BUP-XR in patients with opioid use disorder at high risk of opioid OD. Rapid induction onto long-lasting injectable buprenorphine may be a promising and protective treatment approach in the future.

Implant removal rate after partial carpal arthrodesis in dogs: A retrospective analysis of 22 cases.

Introduction: The purpose of this study is to determine the rate of implant removal after partial carpal arthrodesis and to investigate factors associated with implant removal. Methods: Case records of 22 dogs that underwent partial carpal arthrodesis at two private veterinary referral hospitals were reviewed. Details retrieved were body weight at time of surgery, sex, neuter status, breed, age, cause of carpal hyperextension injury, joint(s) involved in carpal hyperextension injury, laterality, type of implant, administration of post-operative antibiotics, post-operative outcome and indication for implant removal. Association between these factors and implant removal was evaluated. Results: Of 22 partial carpal arthrodesis, 12 (55%) had implant removal due to persistent lameness and 9/12 (75%) returned to full and acceptable function after implant removal. Indications for implant removal were implant interference (8), infection (4), and migration (1). When comparing type of implant, there was a significant difference when observing implant removal rates (p = 0.04). All 5 dogs with pins and wires (100%) required implant removal. Of 17 dogs with a plate, 7 (41.2%) required implant removal. Implant removal was performed on average 114 days post-operative. Discussion: Implant removal after partial carpal arthrodesis was frequent and was commonly indicated due to pin and wire fixation or plate implant interference. This study may impact how we prepare clients for potential post-operative complications and implant removal when recommending partial carpal arthrodesis.

Effects of exercise countermeasures on multisystem function in long duration spaceflight astronauts.

Exercise training is a key countermeasure used to offset spaceflight-induced multisystem deconditioning. Here, we evaluated the effects of exercise countermeasures on multisystem function in a large cohort (N = 46) of astronauts on long-duration spaceflight missions. We found that during 178 ± 48 d of spaceflight, ~600 min/wk of aerobic and resistance exercise did not fully protect against multisystem deconditioning. However, substantial inter-individual heterogeneity in multisystem response was apparent with changes from pre to postflight ranging from -30% to +5%. We estimated that up to 17% of astronauts would experience performance-limiting deconditioning if current exercise countermeasures were used on future spaceflight missions. These findings support the need for refinement of current countermeasures, adjunct interventions, or enhanced requirements for preflight physiologic and functional capacity for the protection of astronaut health and performance during exploration missions to the moon and beyond.

Erratum: Size effects in energy transport between thermal contacts mediated by nanoparticles [Phys. Rev. E 99, 032141 (2019)].

This corrects the article DOI: 10.1103/PhysRevE.99.032141.

Evaluation of Strontium Interference in Calcium Measurement Procedures and Content in Supplements as Measured by ICP-MS.

BACKGROUND: Bone health supplements containing strontium are available without prescription, however, the effects of strontium interference on clinical laboratory calcium measurement procedures are unknown. METHODS: To evaluate strontium interference on total calcium measurements, plasma pools with exogenously added strontium were measured by 3 total calcium measurement procedures. For ionized calcium measurements, whole blood pools prepared with exogenously added strontium were measured by 2 ionized calcium measurement procedures. An inductively coupled plasma mass spectrometry assay (ICP-MS) was validated for research measurements of strontium content in commercially available supplements. RESULTS: Exogenous strontium addition to plasma caused positive bias for total calcium measurements. Strontium concentrations of 1.0 mg/dL (0.114 mmol/L), 2.5 mg/dL (0.284 mmol/L), and 5.0 mg/Dl (0.568 mmol/L) resulted in mean biases of 1.9% to 3.5%, 4.9% to 9.0%, and 10.8% to 19.2%, respectively, for total calcium measurement procedures. Biases for ionized calcium measurements were less than 4.5% for a strontium concentration of 5.0 mg/dL (0.568 mmol/L). An in-house-developed ICP-MS assay for strontium in commercially available supplements exhibited within-laboratory and within-run coefficients of variation of less than 3%, and a linear response was obtained over the assay analytical measurement range of 10 to 100 000 ng/mL (0.0001 to 1.141 mmol/L). Strontium recovery for the ICP-MS assay was 97.1% to 105.3%. The largest amount of strontium measured in dietary supplements was 395 mg in a 1054 mg tablet. CONCLUSIONS: Some dietary supplements contain larger amounts of strontium than indicated on the product label. High concentrations of strontium may cause significant interference for total calcium measurement procedures, but ionized calcium measurement procedures are not significantly affected.

Clinical characteristics and outcomes using dexmedetomidine in nonintubated patients: A poison center observational study.

PURPOSE: Dexmedetomidine is a central α2 agonist commonly used on intubated patients. It is increasingly being used off-label in nonintubated agitated patients. We sought to determine the overall clinical course, adverse effects, and need for subsequent mechanical ventilation in toxicology patients after treatment with dexmedetomidine. METHODS: This was a retrospective cohort study conducted by chart review of electronic records from the Virginia Poison Control Center from January 1, 2019 to February 4, 2022. Inclusion criteria consisted of all poison center cases where dexmedetomidine was used. The primary outcome was the presence or absence of clinical improvement following dexmedetomidine use. Secondary outcomes included adverse effects, subsequent intubation, or death. RESULTS: During this study period, there were 220 cases in which dexmedetomidine was used to treat agitation. After exclusions, 70 cases were analyzed. The categories included antimuscarinic (n = 19), polysubstance (n = 16), sedative withdrawal (n = 10), unknown agitation (n = 7), sympathomimetic (n = 5), baclofen withdrawal (n = 3), unknown ingestion (n = 3), sedative/hypnotic (n = 2), antipsychotic (n = 2), hallucinogenic (n = 2), and opioid withdrawal (n = 1). Clinical improvement occurred in 62 of 70 patients (89%). There were no deaths. A total of 4 patients were intubated after starting dexmedetomidine, 2 for refractory agitation and 2 for hypoxia after aspiration. CONCLUSION: Global clinical improvement was observed in the agitated toxicology patients administered dexmedetomidine. There was one case of intubation secondary to oversedation. Dexmedetomidine could be a useful adjunctive treatment for agitated toxicologic patients but should be studied further before routinely used.

Capturing the lived experiences of women with lymphoma in pregnancy: a qualitative study.

Lymphoma in pregnancy is a rare and challenging diagnosis that complicates ∼1:6000 pregnancies; posing a series of unique therapeutic, social, and ethical challenges to the patient, her family, and the medical professionals involved. These difficulties are compounded by the paucity of real-world data on the management of LIP, and a lack of relevant support systems for women in this setting. We conducted a retrospective multicenter qualitative study, interviewing women aged ≥18 years of age diagnosed with Hodgkin (HL) or non-Hodgkin lymphoma (NHL) during pregnancy or within 12 months postpartum, between 1 January 2009 and 31 December 2020 from 13 Australasian sites. Semi-structured telephone interviews were conducted, recorded, and analyzed using QSR Int NVivo 12 Pro (March 2020, USA) to quantify salient themes. Of the 32 women interviewed, 20 (63%) were diagnosed during pregnancy (16, 34, and 13% in the 1st, 2nd, and 3rd trimesters, respectively), while 12 (37%) were diagnosed post-partum. Women recalled that their chief concerns at diagnosis were the welfare of their child (n = 13, 41%) and a fear of dying (n = 9, 28%). Perceived diagnostic delay attributed to pregnancy was reported by 41% of participants. Other key themes were communication, educational materials, psychosocial supports, and oncofertility issues. To our knowledge this is the first report capturing the lived experiences of survivors of lymphoma during pregnancy, affording a unique opportunity to consider the management, psychosocial supports, and delivery of care to meet the needs of these women.What is the NEW aspect of your work? To our knowledge, this is the first report capturing and analyzing the healthcare experiences of survivors of Lymphoma in Pregnancy (LIP).What is the CENTRAL finding of your work? Women valued clear and empathic communication, provision of tailored educational materials, access to psychosocial supports (particularly childcare and financial supports), and timely oncofertility management in their healthcare journey.What is (or could be) the SPECIFIC clinical relevance of your work? Women's personal accounts of positive and negative experiences of LIP care provide insights into their specific concerns and needs which can shape healthcare policy and development of a specific framework for managing and supporting patients with LIP (and other cancers).

Clinical outcomes of canine total hip replacement utilizing a BFX lateral bolt femoral stem: 195 consecutive cases (2013-2019).

OBJECTIVE: To evaluate the clinical outcomes of total hip replacements (THR) utilizing a BFX lateral bolt stem in dogs with coxofemoral joint disease. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: A total of 149 dogs representing 195 THR. METHODS: Consecutive THRs utilizing a BFX lateral bolt stem were studied. Preoperative, immediate postoperative, 1-, 2-, 3-, 4-, and 12-month postoperative radiographs were performed. All major and minor complications, revisions, outcomes, subsidence, canal flare index (CFI) were recorded. RESULTS: An intraoperative complication rate of 11.8% was observed. The postoperative complication rate was 13.6%, with 9.2% major and 4.4% minor complications. Complications included: postoperative femur fractures (3.6%), coxofemoral luxation (3.6%), stem failure (0.5%), septic loosening (0.5%), aseptic loosening (0.5%), and acetabular fracture (0.5%). Three dogs underwent prophylactic plating after subjective assessment of cortical thickness. Five of 195 (2.6%) cases underwent explant of their prostheses (median = 3 months). Mean stem subsidence at 1 month postoperatively was 1.22 ± 0.16 mm. An increased CFI was associated with postoperative femur fractures (p < .05). A total of 190 of 195 (97.4%) cases returned to normal function in the long-term follow-up period. CONCLUSION: Use of the BFX lateral bolt stem resulted in minimal postoperative subsidence, a low femoral stem complication rate, and a high rate of achieving normal limb function. CLINICAL SIGNIFICANCE: The BFX lateral bolt stem should be considered in canine THR as the femoral failure rate is low and the long-term success rate is high.

Retained bullets and lead toxicity: a systematic review.

INTRODUCTION: Lead toxicity secondary to retained bullet(s) (RB) after a penetrating gunshot wound is a rare but likely underdiagnosed condition, given the substantial number of firearm injuries in the United States. There is currently no consensus on the indications for surveillance, chelation, or surgical intervention. OBJECTIVE: The purpose of our review is to summarize the literature on systemic lead toxicity secondary to RBs to help guide clinicians in the management of these patients. METHODOLOGY: The primary literature search was conducted in Medline (PubMed), EMBASE, Cochrane, and CENTRAL using the following MESH terms: "chelation" and "lead poisoning" or "lead toxicity" or "lead" and "bullet" or "missile" or "gunshot", or "bullet". RESULTS: The search identified 1,082 articles. After exclusions, a total of 142 articles were included in our final review, the majority of which were case reports. Several factors appear to increase the risk of developing lead toxicity including the location of the RB, the presence of a fracture or recent trauma, number of fragments, hypermetabolic states, and bullet retention duration. Particularly, RBs located within a body fluid compartment like an intra-articular space appear to be at a substantially higher risk of developing lead toxicity. Even though patients with lead toxicity from RBs will have similar symptoms to patients with lead toxicity from other sources, the diagnosis of lead poisoning may occur months or years after a gunshot wound. Symptomatic patients with high blood lead levels (BLLs) tended to improve with a combination of chelation and surgical removal of RBs. CONCLUSIONS: We suggest surveillance with serial BLLs should be performed. Patients with intra-articular RBs appear to be at increased risk of lead toxicity and if possible, early surgical removal of the RBs is warranted, especially given that signs of toxicity are vague, and patients may not have access to follow-up. Long-term chelation should not be used as a surgical alternative and management should be multidisciplinary.

Systemic toxicity from subcutaneous brimonidine injection successfully treated with naloxone.

Brimonidine is a topical ophthalmic alpha-2 adrenergic agonist solution used to treat glaucoma. The toxidrome includes drowsiness, lethargy, hypotension, bradycardia, and respiratory depression when ingested in infants. We report a case of intentional subcutaneous injection of brimonidine in an elderly patient resulting in hypotension and CNS depression that responded to naloxone. A 73-year-old female with a past medical history significant for glaucoma, hypertension, and indwelling pacemaker presented to the emergency department after injecting her brimonidine tartrate ophthalmic solution subcutaneously (SQ). The patient was not taking any antihypertensive medications or opioids. Initial presentation consisted of lethargy, a paced rhythm of 60 bpm, and blood pressure of 91/24 mmHg with a MAP of 46. Due to central nervous system depression, 3 mg of intranasal naloxone was administered. The patient was treated with intravenous fluids and escalating doses of naloxone and required a continuous infusion. Mental status and vital signs subsequently improved. The patient was admitted to the ICU and naloxone was subsequently weaned over 12 h. Systemic central alpha-2 adrenergic agonist toxicity resulted from SQ brimonidine injection. Central alpha-2 adrenergic agonist overdoses present as sympatholytic effects including CNS depression, bradycardia, hypotension, and may mimic the opioid toxidrome. Brimonidine SQ injection has not previously been reported and this case has similar findings to other central alpha-2 adrenergic agonist poisonings. Naloxone has previously shown variable reversal of CNS depression in central alpha-2 overdose. In this case, high-dose naloxone was useful for reversing CNS depression and hemodynamic instability.

Role of SNARE Proteins in the Insertion of KCa3.1 in the Plasma Membrane of a Polarized Epithelium.

Targeting proteins to a specific membrane is crucial for proper epithelial cell function. KCa3.1, a calcium-activated, intermediate-conductance potassium channel, is targeted to the basolateral membrane (BLM) in epithelial cells. Surprisingly, the mechanism of KCa3.1 membrane targeting is poorly understood. We previously reported that targeting of KCa3.1 to the BLM of epithelial cells is Myosin-Vc-, Rab1-and Rab8-dependent. Here, we examine the role of the SNARE proteins VAMP3, SNAP-23 and syntaxin 4 (STX-4) in the targeting of KCa3.1 to the BLM of Fischer rat thyroid (FRT) epithelial cells. We carried out immunoblot, siRNA and Ussing chamber experiments on FRT cells, stably expressing KCa3.1-BLAP/Bir-A-KDEL, grown as high-resistance monolayers. siRNA-mediated knockdown of VAMP3 reduced BLM expression of KCa3.1 by 57 ± 5% (p ≤ 0.05, n = 5). Measurements of BLM-localized KCa3.1 currents, in Ussing chambers, demonstrated knockdown of VAMP3 reduced KCa3.1 current by 70 ± 4% (p ≤ 0.05, n = 5). Similarly, siRNA knockdown of SNAP-23 reduced the expression of KCa3.1 at the BLM by 56 ± 7% (p ≤ 0.01, n = 6) and reduced KCa3.1 current by 80 ± 11% (p ≤ 0.05, n = 6). Also, knockdown of STX-4 lowered the BLM expression of KCa3.1 by 54 ± 6% (p ≤ 0.05, n = 5) and reduced KCa3.1 current by 78 ± 11% (p ≤ 0.05, n = 5). Finally, co-immunoprecipitation experiments demonstrated associations between KCa3.1, VAMP3, SNAP-23 and STX-4. These data indicate that VAMP3, SNAP-23 and STX-4 are critical for the targeting KCa3.1 to BLM of polarized epithelial cells.