Nuclear pore density controls heterochromatin reorganization during senescence.

During oncogene-induced senescence (OIS), heterochromatin is lost from the nuclear periphery and forms internal senescence-associated heterochromatin foci (SAHFs). We show that an increased nuclear pore density during OIS is responsible for SAHF formation. In particular, the nucleoporin TPR is necessary for both formation and maintenance of SAHFs. Loss of SAHFs does not affect cell cycle arrest but abrogates the senescence-associated secretory phenotype-a program of inflammatory cytokine gene activation. Our results uncover a previously unknown role of nuclear pores in heterochromatin reorganization in mammalian nuclei and demonstrate the importance of heterochromatin organization for a specific gene activation program.

Ultrasound-guided pericapsular nerve block compared with IV opioids in hip injuries: A randomised controlled trial.

STUDY OBJECTIVES: The study aimed to compare the analgesic effect of USG-guided PENG (Peri capsular nerve group) block with Intravenous Nalbuphine hydrochloride (IVN) in patients with hip fracture coming to the emergency department (ED). The purpose was also to monitor the adverse effects and rescue analgesic requirements in both treatment modalities. METHODS: The study was an open-label randomised controlled trial (RCT) comparing PENG block versus IVN in treating patients with femoral head and neck fractures, as well as pubic rami fracture of the hip (HF). The participants in the PENG group received a USG-guided PENG block by injection of 25 ml of 0.25% bupivacaine, whereas the IVN group received 0.15 mg/kg of nalbuphine. An emergency physician with expertise in ultrasound-guided nerve blocks performed the PENG blocks. The primary outcome was to measure the improvement of the NRS (Numerical rating scale) score at 30 min in both static position (Patient-chosen position for the best comfort) and dynamic position (15-degree passive affected lower limb elevation). Secondary outcomes were to measure static and dynamic NRS pain scores at 2 h, 4 h, and 6 h after intervention in both groups. The requirement for rescue analgesia, adverse events and any block-related complications were also recorded. RESULTS: A total of 60 patients with HF were included in the final analysis. The static and dynamic NRS score was significantly lower in the PENG group compared to the IVN group at 30 min, 2 h, 4 h, and 6 h post-intervention. In the PENG group, the static NRS score was improved by 5.73 ± 1.17, while In the IVN group, the static NRS score was just improved by 2.13 ± 0.97 at 30 min. In the same duration, the Dynamic NRS score in the PENG group was improved by 6.13 ± 1.38, while In the IVN group, it improved just by 2.43 ± 1.28. Rescue analgesia was required in 50.0% of patients in the IVN group but none in the PENG group. Further, no block-related complications or adverse events were observed in the patients of the PENG group. CONCLUSION: The study provides evidence that the ultrasound-guided PENG block has a better analgesic effect and has fewer adverse events than IV opioids in patients with HF.

Evaluation of a scoring system for vein suitability in platelet apheresis donors.

INTRODUCTION: Donor vein assessment for the selection of good quality veins is crucial for a successful apheresis procedure. This study intends to find out the effectiveness of a vein assessment scoring tool (VST) used and found to be effective in selecting whole blood donors to reduce the difficulty in identifying good quality veins for the plateletpheresis procedure. MATERIALS AND METHODS: This was a prospective observational study on platelet apheresis donors with the application of a VST consisting of three vein descriptor parameters (vein visibility, vein palpability, and vein size) with 5 Likert-type responses constituting a score of 0-12 for each arm. Two vein assessors independently evaluated the vein in both arms and marked their responses blinded from each other as well from the principal investigator. The scores were then calculated and analyzed at the end of the study for their association with phlebotomy and procedural outcomes. RESULTS: A total of 190 donors were recruited. The mean scores for the arms with successful and failed phlebotomy were 9.1 and 9.4 (SD 2.3), respectively. The intra-class correlation Alpha Cronbach value was 0.834 and 0.837 for total scoring in the left arm and right arm, respectively, between the two assessors. Scores neither showed a correlation with other outcomes like low flow alarms, hematoma formation, number of phlebotomy attempts, and procedure completion. CONCLUSION: The study showed that the vein score tool did not truly predict the phlebotomy outcome in apheresis donors, though there was a good degree of inter-assessor reliability.

Human Neural Larva Migrans Caused by Ophidascaris robertsi Ascarid.

We describe a case in Australia of human neural larva migrans caused by the ascarid Ophidascaris robertsi, for which Australian carpet pythons are definitive hosts. We made the diagnosis after a live nematode was removed from the brain of a 64-year-old woman who was immunosuppressed for a hypereosinophilic syndrome diagnosed 12 months earlier.

Successful Use of Cefepime-Zidebactam (WCK 5222) as a Salvage Therapy for the Treatment of Disseminated Extensively Drug-Resistant New Delhi Metallo-ß-Lactamase-Producing Pseudomonas aeruginosa Infection in an Adult Patient with Acute T-Cell Leukemia.

With limited and often toxic treatment options, carbapenem-resistant Gram-negative infections are associated with significant mortality. Cefepime-zidebactam is a promising antibiotic option undergoing a phase 3 trial that has activity against diverse antibiotic-resistant mechanisms in Gram-negative pathogens due to its ß-lactam enhancer mechanism, mediating multiple PBP binding. We report a case of disseminated infection caused by a New Delhi metallo-ß-lactamase-producing, extensively drug-resistant Pseudomonas aeruginosa isolate in a patient with acute T-cell leukemia, successfully managed with cefepime-zidebactam as a salvage therapy.

Ultrasound-guided selective peripheral nerve block compared with the sub-dissociative dose of ketamine for analgesia in patients with extremity injuries.

STUDY OBJECTIVE: To compare the analgesic efficacy of ultrasound-guided selective peripheral nerve block (PNB) and sub-dissociative dose ketamine (SDK) for management of acute pain in patients with extremity injuries presenting to the emergency department (ED). METHODS: This prospective, open-label randomized clinical trial was conducted in the ED of a tertiary care Institute. The patients were provided with either ultrasound-guided selective PNB or SDK. The primary outcome was a reduction in pain in numerical rating scale (NRS) by at least 3 points without rescue analgesia. The secondary outcomes were the need for rescue analgesia, adverse events, and patient satisfaction on either arm. RESULTS: A total of 111 patients with isolated traumatic extremity injuries were included in the final analysis. The NRS score was significantly lower in the PNB group compared to the SDK group at 30, 60,120, 180-, and 240-min post-intervention [group ∼ time interaction, F (5, 647) = 21.53, p ≤ 0.001]. All the patients in the PNB group exhibited primary outcome (NRS ≥3 reductions) at 30 min post-intervention compared with 36 (65%) in the SDK group [-1.02(-1.422,0.622)]. Rescue analgesia was required in 10 (18%) patients in the SDK group compared to none in the PNB group [0.663(0.277,1.050)]. The decrease in NRS score from baseline at 30 min was significantly higher in PNB groups compared to the SDK group [-2.166(-2.640, -1.692)]. The most common side effect reported in the SDK group was dizziness 35(64%), followed by nausea 15(27%). None of the patients in the PNB group reported any complications. Patient satisfaction was higher in the PNB group than SDK group. CONCLUSION: The study provides evidence that ultrasound-guided PNB is superior to SDK in terms of its analgesic efficacy in the management of acute pain due to extremity injuries and is associated with higher patient satisfaction. The need for rescue analgesia was significantly less in the PNB group. SDK was associated with a high incidence of dizziness and nausea.

Genome wide survey, and expression analysis of Ornithine decarboxylase gene associated with alkaloid biosynthesis in plants.

Plant ODC (ornithine decarboxylase) plays a vital role in normalizing cell division in actively growing tissues. The ODC is a key precursor enzyme for nicotine and nornicotine biosynthesis in plants. ODCs are widely present in many plant families but have not been functionally validated and characterized at the molecular level. In the present study, 58 plant ODCs were identified and were found to contain two putative regulatory motifs, specifically PLP (Pyridoxal 5'-phosphate) and Orn/DAP/Arg decarboxylase family 2 pyridoxal-phosphate, that are highly conserved among diverse plant species. Further, the cis-regulatory elements and interacting partners of the gene revealed the importance of ODC in various metabolic pathways. The qRT-PCR revealed highest relative expression of ODC in floral meristem and roots. Our results suggest that ODC can be effectively used as an ideal candidate for engineering polyamine biosynthesis and would be crucial for developing ultra-low nicotine content tobacco lines via genome editing.

Repurposing an Antiepileptic Drug for the Treatment of Glioblastoma.

PURPOSE: Glioblastoma multiforme (GBM) is a grade IV, highly proliferative, and malignant form of brain tumor with a 5-year survival rate at ~ 5%. Current treatment strategies for GBM include surgery, radiation, and chemotherapy. Major challenges in GBM management include difficulties in surgical resection due to brain's vital functions and GBM metastasis, development of resistance to temozolomide (TMZ), and protection of tumor by blood brain barrier (BBB). Therefore, we aimed to discover a novel therapeutic for GBM by targeting its metabolic reprogramming. METHOD: We screened metabolic inhibitors by their effects on GBM cell viability by MTT assay. We discovered an FDA-approved drug stiripentol (STP) in our screening of metabolic inhibitors in GBM cells. STP is used for Dravet syndrome (a rare epilepsy). We further tested efficacy of STP using proliferation assay, clonogenic assay, in vitro migration assay, cell cycle assay, apoptosis assay, and in U87 3D spheroids. We also tested the toxicity of STP, and combinations used in the study on normal human dermal fibroblasts. RESULTS: STP was effective in decreasing GBM cell viability, proliferation, clonogenic ability, and migration. Moreover, cell cycle changes were involved but robust apoptosis was absent in STP's anticancer effects. STP was effective in 3D spheroid models, and in TMZ-resistant cells. STP showed additive or synergistic effect with TMZ in different anticancer assays on GBM cells and was considerably less toxic in normal cells. CONCLUSION: Our results indicate that STP can be an effective GBM therapeutic that enhances the effects of TMZ on GBM cells. Importantly, STP reduced viability of TMZ-resistant cells. Our results warrant further studies in the mechanistic basis of STP's effects on GBM cells and the preclinical potential of STP in animal models.

Influence of 3% Hypertonic Saline Versus 0.9% Saline on Intraoperative Maintenance Fluid Requirements in Adult Patients Undergoing Major Open Abdominal Surgeries: Randomized Controlled Study.

BACKGROUND: Three percent hypertonic saline (3% HTS) acts like an osmotic buffer and draws fluid from the extracellular space into the intravascular compartment. Primary objective was to evaluate whether use of 3% HTS resulted in a difference in intraoperative maintenance fluid requirement versus 0.9% saline (NS). Secondary objectives were to evaluate differences in 24 h fluid requirements and safety of 3% HTS. METHODS: Adult patients of either sex, 18-65 years, undergoing elective major open abdominal surgeries were randomized to receive infusions of 3% HTS or NS at 1 ml/kg/hr through large bore peripheral i.v cannulas, or central venous catheters after anesthesia induction. Intraoperative maintenance fluids were administered to maintain mean arterial pressure (≥70 mmHg), urine output (≥0.5 ml/kg/hr) and central venous pressure of 8-10 cm H2O. RESULTS: Ninety-three patients completed the study (46 in 3% HTS and 47 in NS group). No difference was seen in the volume of intraoperative maintenance fluids (3% HTS vs NS; 2243.9 ± 896.7 ml vs 2093.6 ± 868.7 ml; P = 0.34). Similarly, the 24 h postoperative fluid requirement was not different (3% HTS vs NS; 2006.6 ± 398.6 ml vs 2018.3 ± 389.3 ml; P = 0.94). Patients in 3% HTS group had statistically but not clinically significant higher serum sodium values at postoperative 12th and 24 h. No complication like thrombophlebitis or tissue ischemia was reported due to administration of 3% HTS through peripheral lines. CONCLUSION: Administration of 3% HTS did not reduce intraoperative maintenance fluid requirements in patients undergoing major open abdominal surgeries. TRIAL REGISTRATION: CTRI/2019/09/021032.

Coordinated Actions of Cas9 HNH and RuvC Nuclease Domains Are Regulated by the Bridge Helix and the Target DNA Sequence.

CRISPR-Cas systems are RNA-guided nucleases that provide adaptive immune protection in bacteria and archaea against intruding genomic materials. Cas9, a type-II CRISPR effector protein, is widely used for gene editing applications since a single guide RNA can direct Cas9 to cleave specific genomic targets. The conformational changes associated with RNA/DNA binding are being modulated to develop Cas9 variants with reduced off-target cleavage. Previously, we showed that proline substitutions in the arginine-rich bridge helix (BH) of Streptococcus pyogenes Cas9 (SpyCas9-L64P-K65P, SpyCas92Pro) improve target DNA cleavage selectivity. In this study, we establish that kinetic analysis of the cleavage of supercoiled plasmid substrates provides a facile means to analyze the use of two parallel routes for DNA linearization by SpyCas9: (i) nicking by HNH followed by RuvC cleavage (the TS (target strand) pathway) and (ii) nicking by RuvC followed by HNH cleavage (the NTS (nontarget strand) pathway). BH substitutions and DNA mismatches alter the individual rate constants, resulting in changes in the relative use of the two pathways and the production of nicked and linear species within a given pathway. The results reveal coordinated actions between HNH and RuvC to linearize DNA, which is modulated by the integrity of the BH and the position of the mismatch in the substrate, with each condition producing distinct conformational energy landscapes as observed by molecular dynamics simulations. Overall, our results indicate that BH interactions with RNA/DNA enable target DNA discrimination through the differential use of the parallel sequential pathways driven by HNH/RuvC coordination.

Liver transplantation in propionic and methylmalonic acidemia: A single center study with literature review.

BACKGROUND: Organic acidemias, especially propionic acidemia (PA) and methylmalonic acidemia (MMA), may manifest clinically within the first few hours to days of life. The classic presentation in the newborn period includes metabolic acidosis, hyperlactatemia, and hyperammonemia that is precipitated by unrestricted protein intake. Implementation of newborn screening to diagnose and initiate early treatment has facilitated a reduction in neonatal mortality and improved survival. Despite early diagnosis and appropriate management, these individuals are prone to have recurrent episodes of metabolic acidosis and hyperammonemia resulting in frequent hospitalizations. Liver transplantation (LT) has been proposed as a treatment modality to reduce metabolic decompensations which are not controlled by medical management. Published reports on the outcome of LT show heterogeneous results regarding clinical and biochemical features in the post transplantation period. As a result, we evaluated the outcomes of LT in our institution and compared it to the previously published data. STUDY DESIGN/METHODS: We performed a retrospective chart review of nine individuals with PA or MMA who underwent LT and two individuals with MMA who underwent LT and kidney transplantation (KT). Data including number of hospitalizations, laboratory measures, cardiac and neurological outcomes, dietary protein intake, and growth parameters were collected. RESULTS: The median age of transplantation for subjects with MMA was 7.2 years with a median follow up of 4.3 years. The median age of transplantation for subjects with PA was 1.9 years with a median follow up of 5.4 years. The survival rate at 1 year and 5 years post-LT was 100%. Most of our subjects did not have any episodes of hyperammonemia or pancreatitis post-LT. There was significant reduction in plasma glycine post-LT. One subject developed mild elevation in ammonia post-LT on an unrestricted protein diet, suggesting that protein restriction may be indicated even after LT. CONCLUSION: In a large single center study of LT in MMA and PA, we show that LT may reduce the incidence of metabolic decompensation. Moreover, our data suggest that LT may be associated with reduced number of hospitalizations and improved linear growth in individuals with PA and MMA.

CXCL12 regulates platelet activation via the regulator of G-protein signaling 16.

The regulators of G protein signaling (RGS) protein superfamily negatively controls G protein-coupled receptor signal transduction pathways. One of the members of this family, RGS16, is highly expressed in megakaryocytes and platelets. Studies of its function in platelet and megakaryocyte biology have been limited, in part, due to lack of pharmacological inhibitors. For example, RGS16 overexpression inhibited CXC chemokine receptor 4 (CXCR4)-mediated megakaryocyte migration. More recent studies showed that the chemokine stromal cell-derived factor (SDF1α or CXCL12) regulates platelet function via CXCR4. Based on these considerations, the present study investigated the capacity of RGS16 to regulate CXCL12-dependent platelet function, using the RGS16 knockout mouse model (Rgs16(-/-)). RGS16-deficient platelets had increased protease activated receptor 4 and collagen-induced aggregation, as well as increased CXCL12-dependent agonist-induced aggregation, dense and alpha granule secretion, integrin αIIbß3 activation and phosphatidylserine exposure compared to those from WT littermates. CXCL12 alone did not stimulate aggregation or secretion in either RGS16-deficient or WT platelets. Furthermore, platelets from Rgs16(-/-) mice displayed enhanced phosphorylation of ERK and Akt following CXCL12 stimulation relative to controls. Finally, we also found that PKCδ is involved in regulating CXCL12-dependent activation of ERK and Akt, in the Rgs16-deficient platelets. Collectively, our findings provide the first evidence that RGS16 plays an important role in platelet function by modulating CXCL12-dependent platelet activation.

Characterization of a novel function-blocking antibody targeted against the platelet P2Y1 receptor.

OBJECTIVE: Platelet hyperactivity is associated with vascular disease and contributes to the genesis of thrombotic disorders. ADP plays an important role in platelet activation and activates platelets through 2 G-protein-coupled receptors, the Gq-coupled P2Y1 receptor (P2Y1R), and the Gi-coupled P2Y12 receptor. Although the involvement of the P2Y1R in thrombogenesis is well established, there are no antagonists that are currently available for clinical use. APPROACH AND RESULTS: Our goal is to determine whether a novel antibody targeting the ligand-binding domain, ie, second extracellular loop (EL2) of the P2Y1R (EL2Ab) could inhibit platelet function and protect against thrombogenesis. Our results revealed that the EL2Ab does indeed inhibit ADP-induced platelet aggregation, in a dose-dependent manner. Furthermore, EL2Ab was found to inhibit integrin GPIIb-IIIa activation, dense and α granule secretion, and phosphatidylserine exposure. These inhibitory effects translated into protection against thrombus formation, as evident by a prolonged time for occlusion in a FeCl3-induced thrombosis model, but this was accompanied by a prolonged tail bleeding time. We also observed a dose-dependent displacement of the radiolabeled P2Y1R antagonist [(3)H]MRS2500 from its ligand-binding site by EL2Ab. CONCLUSIONS: Collectively, our findings demonstrate that EL2Ab binds to and exhibits P2Y1R-dependent function-blocking activity in the context of platelets. These results add further evidence for a role of the P2Y1R in thrombosis and validate the concept that targeting it is a relevant alternative or complement to current antiplatelet strategies.

The regulator of G-protein signaling 18 regulates platelet aggregation, hemostasis and thrombosis.

Regulators of G protein signaling (RGS) proteins are known to interact with and negatively regulate/turn-off G protein activation. RGS18 is identified as an R4 subfamily member of this family with specific expression in hematopoietic progenitors, myeloerythroid cells, megakaryocytes and platelets. Studies focused on understanding its function in platelet biology have been limited, in part, due to lack of pharmacological inhibitors. Thus, the present study investigated the function of RGS18 in platelets, using the RGS18 knockout mouse model (RGS18(-/-)). We identified phenotypic differences between RGS18(-/-) and wild-type (WT) mice, and show that RGS18 plays a significant role in hemostasis and thrombosis. Hence, RGS18 deficiency markedly shortened bleeding as well as occlusion times (in vivo). Furthermore, RGS18(-/-) platelets displayed hyper-responsiveness with regards to agonist induced aggregation (in vitro). This gain of function phenotype may serve as the mechanism or explain, at least in part, the enhanced hemostasis and thrombosis phenotype observed in the RGS18 deletion mice. Collectively, our findings provide valuable insight and highlight a critical and direct role for RGS18 in modulating platelet function.

Arachidonic acid-derived signaling lipids and functions in impaired healing.

Very little is known about lipid function during wound healing, and much less during impaired healing. Such understanding will help identify what roles lipid signaling plays in the development of impaired/chronic wounds. We took a lipidomics approach to study the alterations in lipid profile in the LIGHT(-/-) mouse model of impaired healing which has characteristics that resemble those of impaired/chronic wounds in humans, including high levels of oxidative stress, excess inflammation, increased extracellular matrix degradation and blood vessels with fibrin cuffs. The latter suggests excess coagulation and potentially increased platelet aggregation. We show here that in these impaired wounds there is an imbalance in the arachidonic acid (AA) derived eicosonoids that mediate or modulate inflammatory reactions and platelet aggregation. In the LIGHT(-/-) impaired wounds there is a significant increase in enzymatically derived breakdown products of AA. We found that early after injury there was a significant increase in the eicosanoids 11-, 12-, and 15-hydroxyeicosa-tetranoic acid, and the proinflammatory leukotrienes (LTD4 and LTE) and prostaglandins (PGE2 and PGF2α ). Some of these eicosanoids also promote platelet aggregation. This led us to examine the levels of other eicosanoids known to be involved in the latter process. We found that thromboxane (TXA2 /B2 ), and prostacyclins 6kPGF1α are elevated shortly after wounding and in some cases during healing. To determine whether they have an impact in platelet aggregation and hemostasis, we tested LIGHT(-/-) mouse wounds for these two parameters and found that, indeed, platelet aggregation and hemostasis are enhanced in these mice when compared with the control C57BL/6 mice. Understanding lipid signaling in impaired wounds can potentially lead to development of new therapeutics or in using existing nonsteroidal anti-inflammatory agents to help correct the course of healing.

Third-hand Smoke: Impact on Hemostasis and Thrombogenesis.

Cigarette smoking is a major risk factor for acute coronary thrombosis. In fact, both active/first-hand smoke and passive/second-hand smoke exposure are known to increase the risk of coronary thrombosis. Although recently a new risk has been identified and termed third-hand smoke (THS), which is the residual tobacco smoke contaminant that remains after a cigarette is extinguished, it remains to be determined whether it can also enhance the risk of thrombogenesis, much like first-hand smoke and second-hand smoke. Therefore, the present studies investigated the impact of THS exposure in the context of platelet biology and related disease states. It was found that THS-exposed mice exhibited an enhanced platelet aggregation and secretion responses as well as enhanced integrin GPIIb-IIIa activation. Furthermore, it was found that THS exposure shortens the tail bleeding time and the occlusion time in a model of thrombosis. Thus, our data demonstrate for the first time (at least in mice) that THS exposure increases the risk of thrombosis-based disease states, which is attributed, at least in part, to their hyperactive platelets.

Tumor necrosis factor inhibitor-induced serositis.

A 46-year-old man with a history of asthma and psoriatic arthritis on adalimumab presented with fever, tachycardia, and hypoxia. He was diagnosed with pleural effusion and started on antibiotics, as it was noted to be an exudative effusion. Patient failed to improve on multiple courses of antibiotics, and his blood and pleural fluid cultures were negative. He was then started on prednisone 1 mg/kg and showed remarkable recovery. He was diagnosed with adalimumab-induced serositis.

The impact of atrial fibrillation and its treatment on dementia.

Atrial fibrillation (AF) is a very common tachyarrhythmia and is becoming increasingly prevalent, while dementia is a neurological condition manifested as loss of memory and cognitive ability. Both these conditions share several common risk factors. It is becoming increasingly evident that AF increases the risk of dementia. There are several pathophysiological mechanisms by which AF can cause dementia. AF increases the stroke risk and strokes are strongly associated with dementia. Besides stroke, altered cerebral blood flow in AF and cerebral microbleeds from anticoagulation may enhance the risk of dementia. Maintaining sinus rhythm may therefore decrease this risk. Catheter ablation is emerging as an effective alternative to maintain patients in sinus rhythm. This procedure has also shown promise in decreasing the risk of all types of dementia. Besides maintaining sinus rhythm and oral anticoagulation, aggressive risk factor modification may reduce the likelihood or delay the onset of dementia.